https://visualize.jove.com/140303-a-model-for-histone-nonhistone-control-of-ontogenesis monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11537.jpg Histone Modification The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression. Acetylation The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,... https://www.jove.com/v/11537 152 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11541.jpg Histone Variants at the Centromere Histone variants are the histone proteins with structural and sequence variations. These variants may be regarded as “mutant” forms that replace their canonical histone counterparts in the nucleosomes. Specific post-translational modifications on the histone variants enable further chromatin complexity and regulate tissue-specific gene expression. The most common histone variants are from histone H2A, H2B, and linker histone H1 families. However, several variants of histone H3 variants are also... https://www.jove.com/v/11541 150 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11542.jpg Inheritance of Chromatin Structures Epigenetics is the study of inherited changes in a cell's phenotype without changing the DNA sequences. It provides a form of memory for the differential gene expression pattern to maintain cell lineage, position-effect variegation, dosage compensation, and maintenance of chromatin structures such as telomeres and centromeres. For example, the structure and location of the centromere on chromosomes are epigenetically inherited. Its functionality is not dictated or ensured by the underlying DNA... https://www.jove.com/v/11542 197 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12222.jpg Heterochromatin The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions that take up more dye are called heterochromatin. Heterochromatin is further classified into two forms – constitutive heterochromatin and facultative heterochromatin. Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th... https://www.jove.com/v/12222 158 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12222.jpg Heterochromatin The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions that take up more dye are called heterochromatin. Heterochromatin is further classified into two forms – constitutive heterochromatin and facultative heterochromatin. Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th... https://www.jove.com/v/13186 158 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11537.jpg Histone Modification The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression. Acetylation The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,... https://www.jove.com/v/13187 152 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56631.jpg Isolation and Cultivation of Neural Progenitors Followed by Chromatin-Immunoprecipitation of Histone 3 Lysine 79 Dimethylation Mark We present an effective and reproducible method to isolate and culture neural progenitor cells from embryonic and postnatal brain tissue for chromatin immunoprecipitation (ChIP) of histone 3 lysine 79 dimethylation (H3K79me2) - a histone mark located within the globular domain of histone 3. https://www.jove.com/v/56631 609 2018-01-26T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58222.jpg Repressing Gene Transcription by Redirecting Cellular Machinery with Chemical Epigenetic Modifiers Regulation of the chromatin environment is an essential process required for proper gene expression. Here, we describe a method for controlling gene expression through the recruitment of chromatin-modifying machinery in a gene-specific and reversible manner. https://www.jove.com/v/58222 628 2018-09-20T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59382.jpg HOX Loci Focused CRISPR/sgRNA Library Screening Identifying Critical CTCF Boundaries A CRISPR/sgRNA library has been applied to interrogating protein-coding genes.However, the feasibility of a sgRNA library to uncover the function of a CTCF boundary in gene regulation remains unexplored. Here, we describe a HOX loci specific sgRNA library to elucidate the function of CTCF boundaries in HOX loci. https://www.jove.com/v/59382 610 2019-03-31T21:00:00+00:00 JoVE no https://visualize.jove.com/226182-analysis-of-integrate-to-threshold-neural-coding-schemes monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12184.jpg The Role of Ion Channels in Neuronal Computation A postsynaptic neuron usually receives numerous impulses from several other presynaptic neurons. The axon hillock of the postsynaptic neuron integrates all these signals and determines the likelihood of firing an action potential. Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential. https://www.jove.com/v/12184 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14521.jpg Difference from Background: Limit of Detection The limit of detection (LOD) is the smallest amount of analyte that can be distinguished from the background noise. The LOD value corresponds to the concentration at which the analyte signal is three times larger than the standard deviation of the blank signal. Below this value, the analyte signal cannot be differentiated from the background noise. It is calculated by dividing the calibration slope by 3 times the standard deviation of the blank signals. The LOD indicates the presence or absence... https://www.jove.com/v/14521 65 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14891.jpg Graded Potential Graded potentials are localized fluctuations in the cell membrane's electrical charge, commonly found in the dendrites of neurons. The magnitude of these potential changes depends on the strength of the initiating stimulus. In a membrane at its resting potential, a graded potential signifies a voltage shift either above -70 mV or below -70 mV. Graded potentials fall into two categories: depolarizing and hyperpolarizing. Depolarizing graded potentials typically occur when sodium (Na+) or calcium... https://www.jove.com/v/14891 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14899.jpg Integration of Synaptic Events Synaptic integration mainly includes the summation of graded potentials. Graded potentials, regardless of their type, cause subtle alterations in membrane voltage, resulting in either depolarization or hyperpolarization. These incremental changes, when combined or summed, can propel the neuron toward its threshold. Consider, for example, a membrane experiencing a +15 mV shift, causing it to depolarize from -70 mV to -55 mV. In this scenario, graded potentials govern the membrane's ability to... https://www.jove.com/v/14899 88 2025-06-13T16:06:36+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14900.jpg Neural Circuits Neural circuits and neuronal pools are two of the main structures found in the nervous system. Neural circuits are networks of neurons that work together to carry out a specific task or process. They consist of interconnected neurons and glial cells, which provide structural and metabolic support. Neuronal pools are collections of nerve cells with similar functions and interact through chemical and electrical signals. These pools include both interneurons (the central neural circuit nodes that... https://www.jove.com/v/14900 85 2025-06-13T16:07:11+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15081.jpg Integrator and Differentiator Op-amp circuits have significant applications in various fields, including automotive engineering. One such application is cruise control systems in cars, where op-amp circuits are integral for maintaining a constant speed. In these systems, op-amps function as both integrators and differentiators. An integrator within an op-amp circuit produces an output directly proportional to the integral of the input signal. This is achieved by replacing the feedback resistor in a typical inverting... https://www.jove.com/v/15081 73 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63792.jpg Computational Modeling of Retinal Neurons for Visual Prosthesis Research - Fundamental Approaches We summarize a workflow to computationally model a retinal neuron's behaviors in response to electrical stimulation. The computational model is versatile and includes automation steps that are useful in simulating a range of physiological scenarios and anticipating the outcomes of future in vivo/in vitro studies. https://www.jove.com/v/63792 650 2022-06-21T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64898.jpg Open-Source Real-Time Closed-Loop Electrical Threshold Tracking for Translational Pain Research APTrack is a software plugin developed for the Open Ephys platform that enables real-time data visualization and the closed-loop electrical threshold tracking of neuronal action potentials. We have successfully used this in microneurography for human C-fiber nociceptors and mouse C-fiber and Aδ-fiber nociceptors. https://www.jove.com/v/64898 628 2023-04-21T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65042.jpg Automated Multimodal Stimulation and Simultaneous Neuronal Recording from Multiple Small Organisms We present a method for the flexible chemical and multimodal stimulation and recording of simultaneous neural activity from many Caenorhabditis elegans worms. This method uses microfluidics, open-source hardware and software, and supervised automated data analysis to enable the measurement of neuronal phenomena such as adaptation, temporal inhibition, and stimulus crosstalk. https://www.jove.com/v/65042 508 2023-03-03T22:10:00+00:00 JoVE no https://visualize.jove.com/285830-spectral-analysis-of-alpha-rhythm-during-schultzs-autogenic-training-a-tentative-approach-to-rapid-visualization monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/51412.jpg EEG Mu Rhythm in Typical and Atypical Development Assessment of the EEG mu rhythm provides a unique methodology for examining brain activity and when combined with behaviorally based assays, can be a powerful tool for elucidating aspects of social cognition, such as imitation, in clinical populations. https://www.jove.com/v/51412 710 2014-04-10T05:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53327.jpg Utilizing Electroencephalography Measurements for Comparison of Task-Specific Neural Efficiencies: Spatial Intelligence Tasks This manuscript describes an approach to measure neural activity of humans while solving spatially focused engineering problems. The electroencephalogram methodology helps interpret beta brain wave measurements in terms of neural efficiency, with the aim of ultimately enabling comparisons of task performance both between problem types and between participants. https://www.jove.com/v/53327 417 2016-08-09T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62256.jpg Multi-system Monitoring for Identification of Seizures, Arrhythmias and Apnea in Conscious Restrained Rabbits Using simultaneous video-EEG-ECG-oximetry-capnography, we developed a methodology to evaluate the susceptibility of rabbit models to develop provoked arrhythmias and seizures. This novel recording system establishes a platform to test the efficacy and safety of therapeutics and can capture the complex cascade of multi-system events that culminate in sudden death. https://www.jove.com/v/62256 625 2021-03-27T20:00:00+00:00 JoVE no https://visualize.jove.com/328072-models-of-membranes-of-cerebral-cells-as-substrates-for-information-storage monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/10698/10698_article_thumb_10698.jpg Fluid Mosaic Model The fluid mosaic model was first proposed as a visual representation of research observations. The model comprises the composition and dynamics of membranes and serves as a foundation for future membrane-related studies. The model depicts the structure of the plasma membrane with a variety of components, which include phospholipids, proteins, and carbohydrates. These integral molecules are loosely bound, defining the cell’s border and providing fluidity for optimal function.LipidsThe most... https://www.jove.com/v/10698 94 2026-06-01T13:27:40+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10971.jpg What are Membranes? A key characteristic of life is the ability to separate the external environment from the internal space. To do this, cells have evolved semi-permeable membranes that regulate the passage of biological molecules. Additionally, the cell membrane defines a cell’s shape and interactions with the external environment. Eukaryotic cell membranes also serve to compartmentalize the internal space into organelles, including the endomembrane structures of the nucleus, endoplasmic reticulum and Golgi... https://www.jove.com/v/10971 114 2025-10-23T18:49:36+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11655.jpg What are Membranes? A cell's plasma membrane demarcates the cell's borders and determines the nature of its interaction with the environment. Cells exclude certain substances, take in others, and excrete some others in controlled quantities. The plasma membrane must be flexible to allow certain cells, such as red and white blood cells, to change their shape while passing through narrow capillaries. These are the more obvious plasma membrane functions. In addition, the plasma membrane's surface carries markers that... https://www.jove.com/v/11655 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11657.jpg Fluid Mosaic Model Scientists identified the plasma membrane in the 1890s and its principal chemical components (lipids and proteins) by 1915. The model for plasma membrane structure, proposed in 1935 by Hugh Davson and James Danielli, was the first model to be widely accepted in the scientific community. The model was based on the plasma membrane's "railroad track" appearance in early electron micrographs. Davson and Danielli theorized that the plasma membrane's structure resembled a sandwich with the analogy of... https://www.jove.com/v/11657 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11655.jpg What are Membranes? A cell's plasma membrane demarcates the cell's borders and determines the nature of its interaction with the environment. Cells exclude certain substances, take in others, and excrete some others in controlled quantities. The plasma membrane must be flexible to allow certain cells, such as red and white blood cells, to change their shape while passing through narrow capillaries. These are the more obvious plasma membrane functions. In addition, the plasma membrane's surface carries markers that... https://www.jove.com/v/13929 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18174.jpg Storage A schema is a mental framework that helps individuals organize and interpret information. Schemata, formed from previous experiences, influence how we process new information: how we encode it, the inferences we make, and how we retrieve it. For instance, a schema for what a typical classroom looks like might include desks, a teacher's desk, a whiteboard, and students in such an environment. This expectation helps us quickly understand and navigate new classrooms without needing to analyze each... https://www.jove.com/v/18174 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58998.jpg Assembly and Characterization of Biomolecular Memristors Consisting of Ion Channel-doped Lipid Membranes Soft, low-power, biomolecular memristors leverage similar composition, structure, and switching mechanisms of bio-synapses. Presented here is a protocol to assemble and characterize biomolecular memristors obtained from insulating lipid bilayers formed between water droplets in oil. The incorporation of voltage-activated alamethicin peptides results in memristive ionic conductance across the membrane. https://www.jove.com/v/58998 487 2019-03-09T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61620.jpg A Model Membrane Platform for Reconstituting Mitochondrial Membrane Dynamics Mitochondrial fusion is an important homeostatic reaction underlying mitochondrial dynamics. Described here is an in vitro reconstitution system to study mitochondrial inner-membrane fusion that can resolve membrane tethering, docking, hemifusion, and pore opening. The versatility of this approach in exploring cell membrane systems is discussed. https://www.jove.com/v/61620 631 2020-09-02T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65712.jpg Realistic Membrane Modeling Using Complex Lipid Mixtures in Simulation Studies Membrane lipid diversity in structure and composition is an important contributor to cellular processes and can be a marker of disease. Molecular dynamics simulations allow us to study membranes and their interactions with biomolecules at atomistic resolution. Here, we provide a protocol to build, run, and analyze complex membrane systems. https://www.jove.com/v/65712 451 2023-09-01T21:10:00+00:00 JoVE no https://visualize.jove.com/395088-blood-glucose-monitoring-and-computer-regulation-by-means-of-an-artificial-endocrine-pancreas monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10878.jpg Feedback Loops In most cases, excessive hormone production is prevented by negative feedback—a loop that starts with a stimulus inducing the release of a particular substance, like a hormone, to maintain a certain level before triggering a signal that results in a decrease in further release of the hormone. Blood-sugar Levels For example, an increase in blood glucose levels releases the hormone insulin from beta cells of the pancreas into the bloodstream, delivering insulin to cells throughout the body. https://www.jove.com/v/10878 61 2025-10-23T18:46:57+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14991.jpg Cells and Secretions of the Pancreas The pancreas, a vital organ within the abdominal cavity, plays dual roles in the digestive and endocrine systems, collaborating with exocrine and endocrine cells to maintain optimal digestion and blood sugar levels. Exocrine function is carried out by acinar cells, organized into clusters known as acini. These cells contribute to digestion by releasing substantial quantities of enzyme-rich, alkaline digestive juices. Concurrently, the dispersed clusters of endocrine cells throughout the... https://www.jove.com/v/14991 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14992.jpg Hormones Regulating Blood Glucose Insulin is released by beta cells of the pancreas when blood glucose levels are high. It facilitates glucose absorption and utilization in insulin-dependent cells with insulin receptors on their plasma membranes. Insulin promotes glucose uptake by increasing the number of glucose transport proteins in the cell membrane, allowing glucose to enter the cell. As a result, glucose utilization and ATP production are enhanced. In addition to accelerating glucose uptake and utilization, insulin has... https://www.jove.com/v/14992 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17291.jpg Glucose Homeostasis: Regulation of Blood Glucose Carbohydrates consumed through foods are converted into glucose, a crucial energy source for the body. In the prandial state, high blood glucose levels stimulate the secretion of insulin from the pancreas. Insulin inhibits hepatic glucose production and stimulates glucose uptake and metabolism by muscle and adipose tissue. The excess glucose is converted into glycogen and stored in the liver and muscles. During fasting, when blood glucose levels are low, the pancreas secretes glucagon. it... https://www.jove.com/v/17291 62 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17292.jpg Glucose Homeostasis: Pancreatic Islets and Insulin Secretion The pancreatic islets comprising only 1%-2% of the volume are highly vascularized and innervated mini-organs. They contain five endocrine cell types, including β cells that secrete insulin, which is synthesized as a single polypeptide chain, preproinsulin, processed to proinsulin, and finally to insulin and C-peptide. This process is complex and regulated, involving the Golgi complex, the endoplasmic reticulum, and the secretory granules of the β cell. Insulin and C-peptide are co-secreted in... https://www.jove.com/v/17292 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17306.jpg Hypoglycemia and Glucagon Without prolonged fasting, healthy individuals maintain blood glucose levels above 3.5 mM due to a well-adapted neuroendocrine counterregulatory system that effectively prevents acute hypoglycemia, a potentially life-threatening condition. The primary clinical scenarios for hypoglycemia encompass diabetes treatment, inappropriate production of endogenous insulin or insulin-like substances by tumors, and the use of glucose-lowering agents in non-diabetic individuals. Notably, hypoglycemia in the... https://www.jove.com/v/17306 75 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50374.jpg A Method for Mouse Pancreatic Islet Isolation and Intracellular cAMP Determination Assaying in vitro β-cell function using isolated mouse islets of Langerhans is an important component in the study of diabetes pathophysiology and therapeutics. While many downstream applications are available, this protocol specifically describes the measurement of intracellular cyclic adenosine monophosphate (cAMP) as an essential parameter determining β-cell function. https://www.jove.com/v/50374 753 2014-06-25T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65259.jpg Human Pseudoislet System for Synchronous Assessment of Fluorescent Biosensor Dynamics and Hormone Secretory Profiles This protocol describes a method for the synchronous acquisition and co-registration of intracellular signaling events and the secretion of insulin and glucagon by primary human pseudoislets using the adenoviral delivery of a cyclic adenosine monophosphate (cAMP) biosensor, a cAMP difference detector in situ (cADDis), and a microperifusion system. https://www.jove.com/v/65259 484 2023-11-03T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65581.jpg Hyperglycemic Clamp and Hypoglycemic Clamp in Conscious Mice A hyperglycemic clamp is used for measuring insulin release with a maintained higher blood glucose concentration. A hypoglycemic clamp is for measuring glucose production induced by counter-regulatory responses. Both methods use the same surgical procedure. Here, we present a clamp technique to assess systemic glucose metabolism. https://www.jove.com/v/65581 455 2024-01-26T21:10:00+00:00 JoVE no https://visualize.jove.com/488204-effects-of-early-visual-and-complex-stimulation-on-learning-brain-biochemistry-and-electrophysiology monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14944.jpg Higher Mental Functions of Brain: Learning and Memory Memory is one of the most vital higher mental functions of the brain. Memory is closely related to learning because it enables us to retain information and experiences from our past to use them in our present life. It also helps us to remember facts, events, and skills, such as riding a bike or swimming. There are two types of memory — declarative memory, which involves memorizing facts or events, and procedural memory, which enables us to remember how to do something like writing or playing an... https://www.jove.com/v/14944 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17745.jpg Neuroplasticity Neuroplasticity reflects the brain's remarkable capacity to adapt and evolve, responding dynamically to learning, experiences, or injury by reorganizing its neural circuitry. This reorganization involves creating new neural connections and refining old ones through a series of biological processes that contribute to the brain's lifelong development and adaptability. • The brain's ability to change begins with the growth of dendrites and axons, which effectively increases the structural... https://www.jove.com/v/17745 61 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50694.jpg Visualizing the Effects of a Positive Early Experience, Tactile Stimulation, on Dendritic Morphology and Synaptic Connectivity with Golgi-Cox Staining This paper describes the procedures for tactile stimulation of rat pups and subsequent Golgi-Cox staining of neuronal morphology. Tactile stimulation is a positive experience that is administered in the perinatal period by stroking pups with a household duster. Golgi-cox staining is a reliable procedure permitting the visualization of entire neurons. https://www.jove.com/v/50694 523 2013-09-25T16:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53002.jpg Combined Shuttle-Box Training with Electrophysiological Cortex Recording and Stimulation as a Tool to Study Perception and Learning Shuttle-box avoidance learning is well-established in behavioral neuroscience. This protocol describes how shuttle-box learning in rodents can be combined with site-specific electrical intracortical microstimulation (ICMS) and simultaneous chronical in vivo recordings as a tool to study multiple aspects of learning and perception. https://www.jove.com/v/53002 523 2015-10-22T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61474.jpg Measuring Statistical Learning Across Modalities and Domains in School-Aged Children Via an Online Platform and Neuroimaging Techniques Presented here is a protocol introducing a set of child-friendly statistical learning tasks geared towards examining children’s learning of temporal statistical patterns across domains and sensory modalities. The developed tasks collect behavioral data using the web-based platform and task-based functional magnetic resonance imaging (fMRI) data for examining neural engagement during statistical learning. https://www.jove.com/v/61474 485 2020-06-30T21:00:00+00:00 JoVE no https://visualize.jove.com/527340-serum-prolactin-concentrations-related-to-copper-or-inert-intrauterine-devices-iuds-in-women monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10906.jpg Oogenesis In human women, oogenesis produces one mature egg cell or ovum for every precursor cell that enters meiosis. This process differs in two unique ways from the equivalent procedure of spermatogenesis in males. First, meiotic divisions during oogenesis are asymmetric, meaning that a large oocyte (containing most of the cytoplasm) and minor polar body are produced as a result of meiosis I, and again following meiosis II. Since only oocytes will go on to form embryos if fertilized, this unequal... https://www.jove.com/v/10906 127 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16276.jpg Hormonal Regulation of the Menstrual Cycle The ovarian cycle regulates endometrial changes throughout a single menstrual cycle via the coordinated action of gonadotrophin-releasing hormone (GnRH) and gonadotrophins. At puberty, GnRH begins a pulsatile release pattern, which triggers the anterior pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The frequency and amplitude of GnRH pulses vary across the menstrual cycle, with faster pulses favoring LH release and slower pulses favoring FSH release. https://www.jove.com/v/16276 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16316.jpg Birth Control Methods Vasectomy is a surgical form of male sterilization that involves severing and sealing the vasa deferentia, preventing sperm from mixing with semen during ejaculation. Because a vasectomy does not impact the testes' ability to produce testosterone, hormone levels, libido, and sexual function generally remain unchanged. While vasectomy is highly effective in preventing pregnancy, with a success rate near 99.85%, rare cases of recanalization (spontaneous reconnection) can occur. Although vasectomy... https://www.jove.com/v/16316 82 JoVE no https://cloudfront.jove.com/files/ftp_upload/17260/17260_article_thumb_17260.jpg Intrauterine Drug Delivery Systems Controlled-release systems for intravaginal and intrauterine drug delivery have been developed primarily for the administration of contraceptive steroid hormones. These delivery routes circumvent first-pass hepatic metabolism, thereby enhancing bioavailability and allowing for reduced systemic dosages compared to oral administration. Such approaches contribute to improved therapeutic efficacy and patient compliance, particularly in long-term contraceptive regimens.Intravaginal Drug Delivery... https://www.jove.com/v/17260 81 2026-02-12T19:17:26+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63378.jpg Quantitating Iron Transport Across the Mouse Placenta In Vivo Using Nonradioactive Iron Isotopes This article demonstrates how to prepare and administer transferrin-bound nonradioactive isotopic iron for studies of iron transport in mouse pregnancy. The approach for quantifying isotopic iron in fetoplacental compartments is also described. https://www.jove.com/v/63378 525 2022-05-10T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64042.jpg X-Ray Visualization of Intraductal Ethanol-Based Ablative Treatment for Prevention of Breast Cancer in Rat Models A procedure for the delivery of a chemical ablative solution to the rat mammary ductal tree for image-guided preventive treatment of breast cancer is described. Mammary epithelial cells can be targeted with minimal collateral tissue damage through cannulation directly into the nipple opening and intraductal infusion of a 70% ethanol-based ablative solution. https://www.jove.com/v/64042 777 2022-12-09T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65109.jpg Positron Emission Tomography Using 64-Copper as a Tracer for the Study of Copper-Related Disorders The present protocol describes how to perform 64Cu PET/CT and PET/MRI imaging in humans to study copper-related disorders, such as Wilson disease, and the treatment effect on copper metabolism. https://www.jove.com/v/65109 412 2023-04-28T19:40:00+00:00 JoVE no https://visualize.jove.com/561405-counteractive-effects-of-norepinephrine-and-amphetamine-on-quabain-induced-amnesia monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3798.jpg Single Cell Measurement of Dopamine Release with Simultaneous Voltage-clamp and Amperometry The amperometric technique measures dopamine release from a single cell by detecting the oxidative current produced by spontaneous dopamine oxidization. Simultaneous voltage clamp and amperometry methodology reveal the mechanistic relationship between the overall "activity" of dopamine transporter and the regulatory role of this activity on the reverse transport of dopamine. https://www.jove.com/v/3798 450 2012-11-21T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14462.jpg Drugs Acting on Autonomic Ganglia: Stimulants Ganglionic stimulants activate NM nicotinic receptors in autonomic ganglia, falling into two categories: nicotine mimetics [e.g., lobeline, dimethylpiperazine, tetramethylammonium] and muscarinic receptor agonists [e.g., muscarine, methacholine]. The first category's action is rapid and blocked by nicotinic receptor antagonists, while the second category's action is delayed and blocked by atropine-like agents. Nicotine, an alkaloid, affects the heart rate by stimulating sympathetic or... https://www.jove.com/v/14462 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14469.jpg Adrenergic Agonists: Indirect-Acting Agents Indirect-acting adrenergic agonists potentiate the effects of endogenous catecholamines through different mechanisms without directly binding to adrenoceptors. One mechanism involves depleting stored catecholamines by displacing them from synaptic vesicles. These agents, known as "displacers," are transported into vesicles at the expense of noradrenaline. Examples include amphetamine and tyramine, which lack a catechol moiety, resulting in prolonged action, improved oral bioavailability, and... https://www.jove.com/v/14469 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14479.jpg Drugs Affecting Neurotransmitter Release or Uptake Certain drugs can affect how neurotransmitters called catecholamines, are released or taken back up in the adrenergic neuron. They can have different effects on the body's sympathetic transmission. Reserpine, a natural compound found in the Rauwolfia shrub, blocks a transporter called vesicular monoamine transporter (VMAT), which leads to a buildup of catecholamines in the cell and reduces sympathetic transmission. Another drug called guanethidine works in multiple ways, including blocking... https://www.jove.com/v/14479 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15010.jpg Drugs Affecting Neurotransmitter Synthesis Drugs affecting neurotransmitter synthesis can impact the adrenergic neuron and the synthesis of neurotransmitters. For example, α-methyltyrosine and carbidopa target specific enzymes involved in catecholamine synthesis. α-methyltyrosine inhibits the enzyme tyrosine hydroxylase, which converts tyrosine into dopamine. By blocking this enzyme, α-methyltyrosine reduces dopamine production and other catecholamines. Carbidopa, on the other hand, inhibits the enzyme dopa decarboxylase, which converts... https://www.jove.com/v/15010 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15181.jpg CNS Stimulants: Cocaine, Amphetamines and Cannabinoids CNS stimulants, such as cocaine, amphetamines, and cannabinoids, have varying structures and mechanisms of action that lead to different therapeutic effects and side effects. Cocaine, with its molecular formula C17H21NO4, is a tropane alkaloid and a tertiary amino compound. It has two chemical forms: the hydrochloride salt and the "freebase." The former is in powder form, while the latter involves removing the hydrochloride salt to create a form that can be smoked. Cocaine exerts its effects by... https://www.jove.com/v/15181 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15183.jpg Cognitive Enhancers: Cholinesterase Inhibitors and NMDA Receptor Antagonists Cognitive enhancers, also known as "smart drugs," are substances used to enhance memory, mental alertness, and concentration. These can be natural or synthetic and improve cognition in conditions like Alzheimer's disease (AD) and other neurodegenerative diseases. Some common examples include caffeine, amphetamines, methylphenidate, modafinil, arecoline, donepezil, vortioxetine, and piracetam. These enhancers work on the principle of synaptic plasticity and altered circuit function. They... https://www.jove.com/v/15183 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52151.jpg Disrupting Reconsolidation of Fear Memory in Humans by a Noradrenergic β-Blocker Disrupting reconsolidation is a promising approach to dampen the behavioral expression of fear memory in patients with anxiety disorders or posttraumatic stress disorder. In a series of human fear conditioning studies we showed that disrupting reconsolidation by the noradrenergic β-blocker propranolol is very effective in erasing conditioned fear responding. https://www.jove.com/v/52151 512 2014-12-18T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62127.jpg A Plate-Based Assay for the Measurement of Endogenous Monoamine Release in Acute Brain Slices This method introduces a simple technique for the detection of endogenous monoamine release using acute brain slices. The setup uses a 48-well plate containing a tissue holder for monoamine release. Released monoamine is analyzed by HPLC coupled with electrochemical detection. Additionally, this technique provides a screening method for drug discovery. https://www.jove.com/v/62127 476 2021-08-11T20:00:00+00:00 JoVE no https://visualize.jove.com/576807-fast-isoamylases-in-saliva-from-mucoviscidosis-patients-authors-transl monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4108.jpg Sampling Human Indigenous Saliva Peptidome Using a Lollipop-Like Ultrafiltration Probe: Simplify and Enhance Peptide Detection for Clinical Mass Spectrometry Considering saliva sampling for future clinical application, a lollipop-like ultrafiltration (LLUF) probe was fabricated to fit in the human oral cavity. Direct analysis of undigested saliva by NanoLC-LTQ mass spectrometry demonstrated the ability of LLUF probes to remove large proteins and high abundance proteins, and make low-abundant peptides more detectable. https://www.jove.com/v/4108 517 2012-08-07T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10829.jpg What is Monogastric Digestion? The human body contains a monogastric digestive system. In a monogastric digestive system, the stomach only contains one chamber in which it digests food. Several other animal species also have monogastric digestive systems, including pigs, horses, dogs, and birds. This chapter, however, focuses on the human digestive system. Saliva and Diagnostics Saliva is a watery substance secreted by the salivary glands into the mouth. Human saliva contains 99.5% water with electrolytes, mucus, white... https://www.jove.com/v/10829 110 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10834.jpg Carbohydrate Digestion Carbohydrate digestion and metabolism break down simple and complex carbohydrates from food into saccharides (i.e., sugars) for the body to use as energy. Carbohydrate digestion starts in the mouth during mastication, or chewing. The masticated carbohydrates remain intact in the stomach. Digestion resumes in the duodenum of the small intestine, where pancreatic alpha-amylase and brush border enzymes of the microvilli convert complex carbohydrates to monosaccharides. Finally, the monosaccharides... https://www.jove.com/v/10834 57 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16187.jpg Salivary Glands and Saliva The salivary glands, of which there are three pairs known as the parotid, submandibular, and sublingual glands, play a crucial role in maintaining oral health and initiating the digestive process. Positioned near the ears, beneath the masseter muscle, the parotid glands secrete saliva into the oral cavity through the parotid duct of Stensen. Meanwhile, the submandibular glands, located on the floor of the mouth, secrete saliva through channels named submandibular ducts. The sublingual glands,... https://www.jove.com/v/16187 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62831.jpg Two-layered Membrane Sandwich Method for Laodelphax striatellus Saliva Collection The present protocol describes a method to collect sufficient saliva from piercing-sucking insects using an artificial medium. This is a convenient method for collecting insect saliva and studying salivary function on insect feeding behavior and vector-borne virus transmission. https://www.jove.com/v/62831 373 2021-08-27T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/69154.jpg Spatial Molecular Imaging of the Glycome Using Mass Spectrometry This protocol details the key steps to enable rigorous and reproducible measurement of both glycogen and N-linked glycans using mass spectrometry imaging. https://www.jove.com/v/69154 532 2025-11-28T20:40:00+00:00 JoVE no https://visualize.jove.com/598198-a-portable-integer-fft-in-fortran monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16065.jpg Discrete-Time Fourier Series The Discrete-Time Fourier Series (DTFS) is a fundamental concept in signal processing, serving as the discrete-time counterpart to the continuous-time Fourier series. It allows for the representation and analysis of discrete-time periodic signals in terms of their frequency components. Unlike its continuous counterpart, which utilizes integrals, the calculation of DTFS expansion coefficients involves summations due to the discrete nature of the signal. For a discrete-time periodic signal x[n]... https://www.jove.com/v/16065 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16066.jpg Continuous -time Fourier Transform The Fourier series is instrumental in representing periodic functions, offering a powerful method to decompose such functions into a sum of sinusoids. This technique, however, necessitates modification when applied to nonperiodic functions. Consider a pulse-train waveform consisting of a series of rectangular pulses. When these pulses have a finite period, they can be accurately represented by a Fourier series. Yet, as the period approaches infinity, resulting in a single, isolated pulse, the... https://www.jove.com/v/16066 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16070.jpg Parseval's Theorem for Fourier transform Parseval's theorem is a fundamental principle in signal processing that enables the calculation of a signal's energy in either the time domain or the frequency domain. This theorem is pivotal in demonstrating energy conservation between these two domains, ensuring that the computed energy value remains consistent regardless of the domain of analysis. To understand Parseval's theorem, it is essential to first comprehend how signal energy is typically calculated. When considering a signal's... https://www.jove.com/v/16070 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16071.jpg Discrete-time Fourier transform The Discrete-Time Fourier Transform (DTFT) is an essential mathematical tool for analyzing discrete-time signals, converting them from the time domain to the frequency domain. This transformation allows for examining the frequency components of discrete signals, providing insights into their spectral characteristics. In the DTFT, the continuous integral used in the continuous-time Fourier transform is replaced by a summation to accommodate the discrete nature of the signal. One of the notable... https://www.jove.com/v/16071 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16074.jpg Discrete Fourier Transform The Discrete Fourier Transform (DFT) is a fundamental tool in signal processing, extending the discrete-time Fourier transform by evaluating discrete signals at uniformly spaced frequency intervals. This transformation converts a finite sequence of time-domain samples into frequency components, each representing complex sinusoids ordered by frequency. The DFT translates these sequences into the frequency domain, effectively indicating the magnitude and phase of each frequency component present... https://www.jove.com/v/16074 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16075.jpg Fast Fourier Transform The Fast Fourier Transform (FFT) is a computational algorithm designed to compute the Discrete Fourier Transform (DFT) efficiently. By breaking down the calculations into smaller, manageable sections, the FFT significantly reduces the computational complexity involved. Direct computation of an N-point DFT requires N2 complex multiplications, whereas the FFT algorithm needs only (N/2)log⁡2N multiplications, offering a much faster performance. The computational efficiency of the FFT becomes... https://www.jove.com/v/16075 70 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65306.jpg Analysis of the Mitochondrial Density and Longitudinal Distribution in Rat Live-Skeletal Muscle Fibers by Confocal Microscopy Here, we present a protocol to analyze changes in mitochondrial density and longitudinal distribution by live-skeletal muscle imaging using confocal microscopy for mitochondrial network scanning. https://www.jove.com/v/65306 653 2023-12-01T21:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68515.jpg A Multimodal Wide-Field Fourier-Transform Raman Microscope A wide-field Fourier-transform microscope, based on a compact and ultra-stable birefringent interferometer, allows the parallel acquisition of spectra for all pixels of a 2D detector. The time-domain approach enables the disentanglement of photoluminescence and Raman signals, and allows rapid Raman mapping (~5 ms/pixel) with ~1-µm spatial and 23-cm-1 spectral resolution. https://www.jove.com/v/68515 408 2025-12-30T20:40:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/70425.jpg STFEEG-Tool: A Spatial-Temporal-Frequency EEG Analysis Tool for Motor Imagery Brain-Computer Interfaces This study presents a standardized and reproducible protocol for implementing the Spatial-Temporal-Frequency EEG analysis tool (STFEEG) for motor imagery EEG decoding, incorporating configurable spatial-temporal-frequency segmentation, Common Spatial Patterns (CSP)-based feature extraction, multiple classification algorithms, and visualization capabilities. https://www.jove.com/v/70425 336 2026-03-10T20:00:00+00:00 JoVE no https://visualize.jove.com/670586-a-comparison-of-human-and-automated-instruction-of-autistic-children monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4331.jpg Portable Intermodal Preferential Looking (IPL): Investigating Language Comprehension in Typically Developing Toddlers and Young Children with Autism A reliable home-based way to assess the language comprehension of very young typically developing children, as well as those with autism, is described. The method analyzes children's eye gaze while viewing side-by-side images but hearing an audio that matches only one image. Stimuli are designed with young participants in mind. https://www.jove.com/v/4331 611 2012-12-14T19:55:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18627.jpg Modeling in Therapy Modeling, a key technique in therapy, uses observational learning to help clients acquire and practice new skills by watching therapists demonstrate desired behaviors. This approach, rooted in Albert Bandura's concept of vicarious learning, plays a significant role in therapeutic interventions for various psychological conditions, including social anxiety, ADHD, and depression. Participant Modeling Participant modeling involves therapists demonstrating calm and effective behaviors in situations... https://www.jove.com/v/18627 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/19610.jpg Autism Spectrum Disorder Autism spectrum disorder (ASD) is a neurodevelopmental condition marked by persistent deficits in social communication and interaction alongside restrictive and repetitive behaviors or interests. ASD is sometimes accompanied by intellectual impairment. These core symptoms manifest differently among individuals, ranging from mild to severe. The disorder's complexity extends beyond its clinical presentation, encompassing a diverse range of biological, cognitive, and sociocultural influences.<br... https://www.jove.com/v/19610 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/19615.jpg Learning Disabilities Learning disabilities are cognitive disorders caused by neurological impairments that affect cognitive functions like language and reading, without indicating overall intellectual or developmental challenges. These disabilities differ from global intellectual or developmental disabilities as they are limited to distinct cognitive functions. Common learning disabilities include dysgraphia, dyslexia, and dyscalculia, each of which impacts unique aspects of learning. Dyslexia Dyslexia is a... https://www.jove.com/v/19615 85 2025-08-04T17:44:39+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19923/19923_article_thumb_19923.jpg Automatic Processing and Automatic Social Behavior Automatic processing refers to the cognitive operations that occur without conscious intent or awareness, playing a fundamental role in shaping social cognition and behavior. These processes enable individuals to navigate complex social environments efficiently by relying on mental shortcuts and pre-existing knowledge structures known as schemas. One of the most influential mechanisms underlying automatic processing is priming, which subtly activates mental representations through exposure to... https://www.jove.com/v/19923 88 2025-09-18T17:24:15+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58452.jpg Using the Visual World Paradigm to Study Sentence Comprehension in Mandarin-Speaking Children with Autism We present a protocol to examine the use of morphological cues during real-time sentence comprehension by children with autism. https://www.jove.com/v/58452 375 2018-10-03T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58694.jpg Comparing Eye-tracking Data of Children with High-functioning ASD, Comorbid ADHD, and of a Control Watching Social Videos This is a qualitative comparative case study analysis of eye-tracking data on the first moments of social video scenes as viewed by three participants: one with autism spectrum disorder, one with comorbid attention deficit-hyperactive disorder, and one neurotypical control. https://www.jove.com/v/58694 332 2018-12-07T21:00:00+00:00 JoVE no https://visualize.jove.com/685334-automated-information-processing-of-systolic-time-intervals monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13286.jpg Pulse rhythm Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding. Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle... https://www.jove.com/v/13286 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13311.jpg Equipments Used To Measure Blood Pressure Direct Method This invasive approach involves cannulating a peripheral artery. During each cardiac contraction, pressure generates mechanical motion within the catheter, transmitted through rigid, fluid-filled tubing to a transducer. This transducer converts mechanical motion into electrical signals displayed as waveforms on a monitor. An automatic flushing system prevents blood backflow. Due to the potential risk of unexpected arterial blood loss, this method is primarily used in intensive... https://www.jove.com/v/13311 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13314.jpg Assessment of blood pressure in brachial artery(one-step method) This procedural guide systematically measures blood pressure using an oscillometric digital sphygmomanometer, emphasizing accuracy, patient safety, and comfort. Prepare for the Procedure: • Begin with proper hand hygiene to minimize the risk of cross-infection. This practice is essential in all healthcare procedures to ensure patient and caregiver safety. Explain the Procedure to the Patient: • Clearly and thoroughly explain what the patient should expect during the blood pressure... https://www.jove.com/v/13314 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13315.jpg Assessment of blood pressure in brachial artery(two-step method) Measuring blood pressure is a fundamental skill in healthcare that aids in diagnosing and monitoring hypertension and other cardiovascular conditions. An aneroid sphygmomanometer, commonly used in clinical settings, offers a manual and precise method for blood pressure measurement. The technique for using this instrument involves specific steps that must be carefully executed to ensure accuracy. The following detailed description outlines a two-step technique for assessing blood pressure using... https://www.jove.com/v/13315 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13316.jpg Assessing Blood pressure using a doppler ultrasound To obtain accurate blood pressure measurements in clinical settings, especially when traditional methods are insufficient, healthcare professionals utilize the Doppler ultrasound technique. This method uses high-frequency sound waves to detect blood flow within the arteries, which is crucial for patients with conditions that complicate circulatory system assessment. Pre-Procedural Guidelines for Doppler Ultrasound Blood Pressure Assessment: Preparation of Equipment: • Assemble the necessary... https://www.jove.com/v/13316 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13318.jpg Special considerations while measuring blood pressure When assessing blood pressure (BP), healthcare professionals must consider various factors and potential unexpected outcomes to ensure accurate readings and provide proper patient care. Adhering to these guidelines is essential to achieving the most reliable results. Monitoring Both Arms: Monitoring BP in both arms during the initial assessment is advisable, as the systolic value may differ by five to ten mm Hg between arms. For subsequent BP assessments, use the arm with the higher reading.<br... https://www.jove.com/v/13318 88 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52809.jpg Development of an Algorithm to Perform a Comprehensive Study of Autonomic Dysreflexia in Animals with High Spinal Cord Injury Using a Telemetry Device The catheter of a telemetry device is implanted into the abdominal aorta in order to continuously collect beat-by-beat hemodynamic data from animals pre and post-high thoracic spinal cord transection. A novel JAVA software was employed to analyze hemodynamic parameters as well as frequency and intensity of spontaneous episodes of autonomic dysreflexia. https://www.jove.com/v/52809 411 2016-07-29T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55797.jpg Assessment of Sarcoplasmic Reticulum Calcium Reserve and Intracellular Diastolic Calcium Removal in Isolated Ventricular Cardiomyocytes Intracellular calcium recycling plays a critical role in regulation of systolic and diastolic function in cardiomyocytes. Here, we describe a protocol to evaluate sarcoplasmic reticulum Ca2+ reserve and diastolic calcium removal function in cardiomyocytes by a calcium imaging system. https://www.jove.com/v/55797 660 2017-09-18T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67222.jpg Software for Analysis of Heart Rate and Blood Pressure Time-series Data from the Valsalva Maneuver The ValsalvaAnalyzer software includes functions to analyze continuous beat-to-beat electrocardiogram and blood pressure (BP) measurements recorded during the Valsalva maneuver (VM). The computed clinical biomarkers and estimated model outputs provide insight into sympathetic and parasympathetic regulation of heart rate and BP during the VM. https://www.jove.com/v/67222 868 2025-06-27T19:40:00+00:00 JoVE no https://visualize.jove.com/745569-automated-family-classification-in-ambulatory-arrhythmia-monitoring monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13286.jpg Pulse rhythm Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding. Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle... https://www.jove.com/v/13286 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15276.jpg Disturbances in Heart Rhythm Arrhythmia or dysrhythmia refers to an abnormal heart rhythm caused by a defect in the heart's conduction system. It can cause the heart to beat irregularly, too quickly, or too slowly, leading to symptoms like chest pain, shortness of breath, and fainting. Factors such as stress, caffeine, alcohol, nicotine, cocaine, certain drugs, congenital defects, diseases, and electrolyte abnormalities can trigger arrhythmias. Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart... https://www.jove.com/v/15276 89 2025-07-29T16:29:05+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17887/17887_article_thumb_17887.jpg Holter Monitor: 24-Hour Monitoring Holter monitoring is a continuous electrocardiography (ECG) recording that tracks the heart's electrical activity over an extended period, generally 24 to 48 hours. This noninvasive diagnostic tool detects irregular heart rhythms that may not be captured during a standard ECG performed in a clinical setting.DeviceThe Holter monitor is a portable, small device connected to several electrodes on the patient's chest. These electrodes detect the heart's electrical signals and transmit them to the... https://www.jove.com/v/17887 83 2025-06-19T16:09:27+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17939/17939_article_thumb_17939.jpg Dysrhythmias II: Classification of Tachyarrhythmias Tachyarrhythmias are a type of dysrhythmia where the heart rate exceeds 100 beats per minute. Here are some common types of tachyarrhythmias:Sinus TachycardiaSinus tachycardia originates from increased impulses from the sinus node, leading to an elevated heart rate. It is often triggered by stress, fever, or exercise.Patients may experience palpitations, a sensation of a racing heart, dizziness, and chest discomfort.Causes and Risk Factors: Common causes include physical exertion, emotional... https://www.jove.com/v/17939 88 2025-06-19T16:35:48+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17942/17942_article_thumb_17942.jpg Dysrhythmias V: Evaluating Dysrhythmias Dysrhythmias, also known as arrhythmias, are disturbances in the heart's rhythm that range from benign to life-threatening. A thorough evaluation is crucial for appropriate management and involves a comprehensive medical history, physical examination, and various diagnostic tests.Medical HistorySymptoms: Collect detailed information on palpitations, dizziness, syncope, chest pain, and fatigue. Note their onset, frequency, and triggers.Previous Cardiac Issues: Document any history of heart... https://www.jove.com/v/17942 90 2025-06-19T16:36:46+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18437/18437_article_thumb_18437.jpg ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias Arrhythmia is a condition characterized by an irregular heart rhythm, with ECG changes that differ based on its origin and nature. The types of arrhythmias discussed below include atrial, junctional, and ventricular arrhythmias.Atrial ArrhythmiasPremature Atrial Complexes (PACs): PACs are early atrial beats caused by stress, caffeine, alcohol, electrolyte imbalances, hypoxia, hyperthyroidism, or certain medications (e.g., bronchodilators and decongestants). The ECG shows early P waves with an... https://www.jove.com/v/18437 85 2025-06-19T16:15:27+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50073.jpg Measuring Cardiac Autonomic Nervous System (ANS) Activity in Children Measurement of autonomic nervous system activity usually confines the researcher and participant to the laboratory, which may provide an intimidating environment to children. The VU University Ambulatory Monitoring System (VU-AMS) device can record cardiac autonomic control in any setting. The VU-AMS proved very amenable to testing in children. https://www.jove.com/v/50073 585 2013-04-29T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50124.jpg A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis Continuous 12-lead electrocardiographic (ECG) monitoring can identify transient myocardial ischemia, even when asymptomatic, among patients with suspected acute coronary syndrome (ACS). In this article we describe our method for initiating patient monitoring using a Holter device, downloading the ECG data for off-line analysis, and how to utilize the ECG software to identify transient ischemia. https://www.jove.com/v/50124 1091 2012-12-28T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62386.jpg Analyzing Long-Term Electrocardiography Recordings to Detect Arrhythmias in Mice Here we present a step-by-step protocol for a semiautomated approach to analyze murine long-term electrocardiography (ECG) data for basic ECG parameters and common arrhythmias. Data are obtained by implantable telemetry transmitters in living and awake mice and analyzed using Ponemah and its analysis modules. https://www.jove.com/v/62386 367 2021-05-23T20:00:00+00:00 JoVE no https://visualize.jove.com/807252-hybrid-alpha-amylases-produced-by-the-transformants-of-bacillus-subtilis-iii-a-possible-mechanism-of-formation-of-hybird-alpha-amylases monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40771/40771_article_thumb_40771.jpg Bioreactor Controls-III Strain improvement is a foundational strategy in industrial microbiology aimed at maximizing microbial productivity, particularly because natural isolates typically yield commercially valuable products in very low concentrations. Although optimizing the culture medium and environmental conditions can improve yields, these adjustments are inherently limited by the organism’s genetic potential. As a result, the focus shifts toward genetic modifications to enhance biosynthetic capacity. The... https://www.jove.com/v/40771 82 2026-03-12T20:57:27+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40778/40778_article_thumb_40778.jpg Production of Alcohol Continuous fermentation is a key strategy in industrial ethanol production, particularly when efficiency, scalability, and high yields are essential. This approach allows for uninterrupted operation and optimized resource utilization. The primary feedstock, corn starch, undergoes enzymatic hydrolysis facilitated by α-amylase and glucoamylase. These enzymes break down the starch into fermentable sugars such as glucose, which are readily assimilated by fermentative microorganisms.Fermentation... https://www.jove.com/v/40778 87 2026-05-20T18:24:13+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40779/40779_article_thumb_40779.jpg Production of Organic Acids Lactic acid, an important organic acid extensively applied in food, pharmaceutical, and biodegradable polymer industries, is primarily produced via microbial fermentation. This method is favored over chemical synthesis due to its environmental sustainability and capacity for enantiomerically pure product formation. Among various microbial processes, the fermentation of starch-based substrates stands out due to the abundance and renewability of raw materials like corn and potatoes.Hydrolysis of... https://www.jove.com/v/40779 85 2026-03-12T20:35:47+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40781/40781_article_thumb_40781.jpeg Production of Pharmaceuticals Industrial insulin production uses genetically engineered E. coli expressing a proinsulin gene controlled by a tryptophan promoter and containing a methionine linker for later cleavage. The cells also carry ampicillin resistance for selective growth. Seed cultures are stored at −80 °C and production begins by thawing a small amount to inoculate starter cultures, which are progressively scaled to a 50,000-L bioreactor. In the bioreactor, E. coli grow in nutrient-rich media under sterile, tightly... https://www.jove.com/v/40781 90 2026-03-12T20:36:06+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40782/40782_article_thumb_40782.jpg Production of Biopesticides Biopesticides offer a sustainable alternative to chemical pesticides, utilizing microbial agents to control agricultural pests. Bacillus thuringiensis (Bt) is a widely employed bacterium known for its potent insecticidal activity. Bt biopesticides are favored for their specificity to insect pests, minimal environmental impact, and natural degradability.Mechanism of Bt Toxin Action Bt produces insecticidal crystal (Cry) proteins during its sporulation phase. These proteins form parasporal... https://www.jove.com/v/40782 78 2026-03-12T20:35:54+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57488.jpg Ammonia Fiber Expansion (AFEX) Pretreatment of Lignocellulosic Biomass Ammonia fiber expansion (AFEX) is a thermochemical pretreatment technology that can convert lignocellulosic biomass (e.g., corn stover, rice straw, and sugarcane bagasse) into a highly digestible feedstock for both biofuels and animal feed applications. Here, we describe a laboratory-scale method for conducting AFEX pretreatment on lignocellulosic biomass. https://www.jove.com/v/57488 570 2020-04-18T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59169.jpg Inhibition of Aspergillus flavus Growth and Aflatoxin Production in Transgenic Maize Expressing the α-amylase Inhibitor from Lablab purpureus L. Here we present a protocol to analyze Aspergillus flavus growth and aflatoxin production in maize kernels expressing an antifungal protein. Using a GFP-expressing A. flavus strain we monitored the infection and spread of the fungus in mature kernels in real time. The assay is rapid, reliable, and reproducible. https://www.jove.com/v/59169 561 2019-02-15T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63231.jpg Generation of Null Mutants to Elucidate the Role of Bacterial Glycosyltransferases in Bacterial Motility Here, we describe the construction of null mutants of Aeromonas in specific glycosyltransferases or regions containing glycosyltransferases, the motility assays, and flagella purification performed to establish the involvement and function of their encoded enzymes in the biosynthesis of a glycan, as well as the role of this glycan in bacterial pathogenesis. https://www.jove.com/v/63231 749 2022-03-11T21:45:00+00:00 JoVE no https://visualize.jove.com/856615-peptide-antagonists-of-angiotensin-induced-adrenal-catecholamine-release monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14468.jpg Adrenergic Agonists: Direct-Acting Agents Drugs that mimic the action of endogenous catecholamines like noradrenaline and adrenaline are called adrenergic agonists or sympathomimetics. Based on their mechanism of action, sympathomimetics can be classified as direct-, indirect-, or mixed-acting sympathomimetics. Direct-acting adrenergic agonists activate adrenoceptors without affecting presynaptic neurons, making them independent of neuronal catecholamine-depleting agents like reserpine and guanethidine. These agents can be classified... https://www.jove.com/v/14468 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14473.jpg Adrenergic Agonists: Therapeutic Uses Adrenergic agonists have diverse therapeutic uses across various medical conditions and emergencies. Emergency and Intensive Care Unit (ICU) applications: Pressor agents increase blood pressure, heart rate, and contractility in shock and organ failure situations. Dopamine can induce vasodilation and stimulate adrenoceptors. Endogenous catecholamines are effective in treating cardiogenic shock. α2-agonists like clonidine can reverse anesthesia-induced hypertension. Allergies and anaphylaxis:... https://www.jove.com/v/14473 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15023.jpg Antihypertensive Drugs: Angiotensin-Converting Enzyme Inhibitors Angiotensin-converting enzyme (ACE), a vital component of the renin-angiotensin-aldosterone system, is abundant in lung endothelial cells. ACE converts the inactive decapeptide, angiotensin I, into the active octapeptide, angiotensin II. This potent vasoconstrictor narrows blood vessels, increasing resistance to blood flow and elevating blood pressure. Angiotensin II also stimulates aldosterone production, encouraging kidney cells to reabsorb more sodium and water from urine, thereby increasing... https://www.jove.com/v/15023 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15024.jpg Antihypertensive Drugs: Angiotensin II Receptor Blockers In the renin-angiotensin-aldosterone system, a hormone called angiotensin II plays a crucial role. It binds to the AT1 receptors in vascular smooth muscles coupled with Gq proteins. The activation of these receptors activates an enzyme called phospholipase C, which releases two molecules: inositol trisphosphate and diacylglycerol. These molecules cause a chain reaction that leads to the phosphorylation of myosin light chains and promotes interaction between actin and myosin, leading to smooth... https://www.jove.com/v/15024 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15025.jpg Antihypertensive Drugs: Direct Renin Inhibitors The renin-angiotensin-aldosterone system (RAAS) is an intricate physiological pathway involving numerous enzymes and hormones, including renin, angiotensin-converting enzyme (ACE), angiotensin I and II, and aldosterone. Imbalances within this system increase the production of angiotensin II and aldosterone. Increased angiotensin II levels promote vasoconstriction and blood pressure elevation. Concurrently, higher aldosterone levels stimulate sodium and water reabsorption in the kidneys,... https://www.jove.com/v/15025 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15037.jpg Heart Failure Drugs: Inhibitors of Renin-Angiotensin System The activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) contributes to cardiac remodeling, and inhibiting the RAAS is a pharmacological target in heart failure management. As a result, neurohumoral modulation is a crucial treatment principle for managing heart failure. This approach involves using medications like ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), β-blockers, mineralocorticoid receptor antagonists (MRAs), and neutral... https://www.jove.com/v/15037 86 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53866.jpg Receptor Autoradiography Protocol for the Localized Visualization of Angiotensin II Receptors Here we present a protocol to describe the localization of angiotensin II Type 1 receptors in the rat brain by quantitative, densitometric, in vitro receptor autoradiography using an iodine-125 labeled analog of angiotensin II. https://www.jove.com/v/53866 723 2016-06-07T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59391.jpg Nitropeptide Profiling and Identification Illustrated by Angiotensin II Proteomic profiling of tyrosine-nitrated proteins has been a challenging technique due to the low abundance of the 3-nitrotyrosine modification. Here we describe a novel approach for nitropeptide enrichment and profiling by using Angiotensin II as the model. This method can be extended for other in vitro or in vivo systems. https://www.jove.com/v/59391 451 2019-06-16T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63719.jpg Improved Renal Denervation Mitigated Hypertension Induced by Angiotensin II Infusion Here, we present a protocol for renal sympathetic denervation (RDN) in mice with hypertension induced by Angiotensin II infusion. The procedure is repeatable, convenient and allows to study the regulatory mechanisms of RDN on hypertension and cardiac hypertrophy. https://www.jove.com/v/63719 515 2022-05-26T20:00:00+00:00 JoVE no https://visualize.jove.com/879196-dynamic-cardiac-imaging-using-a-focused-phased-array-ultrasound-system monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4416.jpg Murine Fetal Echocardiography Fetal and perinatal death is a common feature when studying genetic alterations affecting cardiac development. High-frequency ultrasound imaging has improved 2-D resolution and can provide excellent information on early cardiac development and is an ideal method to detect the impact on cardiac structure and function prior to death. https://www.jove.com/v/4416 484 2013-02-15T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17881.jpg Imaging Studies for Cardiovascular System I:Echocardiography Cardiac imaging studies encompass a wide range of noninvasive and minimally invasive techniques designed to visualize the heart's structure and function in detail. One such technique is echocardiography, which uses high-frequency ultrasound waves to produce detailed images of the heart, known as echocardiograms. Indications: Echocardiography is utilized to diagnose heart failure, valve disorders, and myocardial infarction. It also assesses cardiac structures' size, shape, and motion, evaluates... https://www.jove.com/v/17881 77 JoVE no https://cloudfront.jove.com/files/ftp_upload/17885/17885_article_thumb_17885.jpg Imaging Studies for Cardiovascular System V: CT Cardiac computed tomography (CT) scanning is an advanced cardiac imaging technique that utilizes CT technology, with or without intravenous (IV) contrast, to produce accurate cross-sectional virtual slices of specific areas of the heart, coronary circulation, and major blood vessels such as the aorta, pulmonary veins, and arteries. The computer processes these slices to generate three-dimensional images. Multidetector CT (MDCT) is a rapid form of CT scanning that captures multiple slices... https://www.jove.com/v/17885 88 2025-06-19T16:08:22+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59148.jpg Evaluating Targeting Accuracy in the Focal Plane for an Ultrasound-guided High-intensity Focused Ultrasound Phased-array System This study describes a protocol to evaluate the targeting accuracy in the focal plane of an ultrasound-guided high-intensity focused ultrasound phased-array system. https://www.jove.com/v/59148 488 2019-03-06T22:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64547.jpg Troubleshooting FoCUS Image Acquisition: Patient Positioning, Transducer Manipulation, and Image Optimization Here, we present a protocol to allow providers to perform focused cardiac ultrasound (FoCUS) in the clinical environment. We describe methods of transducer manipulation, review common pitfalls of transducer movements, and suggest tips to optimize phased array transducer use. https://www.jove.com/v/64547 410 2023-03-03T22:25:00+00:00 JoVE no https://visualize.jove.com/901904-analysis-of-various-indefinite-self-associations monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11037.jpg The Sense of Self: Reflected Self-Appraisal and Social Comparison According to Charles Cooley, we base our image on what we think other people see (Cooley 1902). We imagine how we must appear to others, then react to this speculation. We don certain clothes, prepare our hair in a particular manner, wear makeup, use cologne, and the like—all with the notion that our presentation of ourselves is going to affect how others perceive us. We expect a certain reaction, and, if lucky, we get the one we desire and feel good about it. But more than that, Cooley... https://www.jove.com/v/11037 177 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11038.jpg Self-Schemas In general, a schema is a mental construct consisting of a cluster or collection of related concepts (Bartlett, 1932). There are many different types of schemata, and they all have one thing in common: schemata are a method of organizing information that allows the brain to work more efficiently. When a schema is activated, the brain makes immediate assumptions about the person or object being observed. More specifically, self-schemas refer to the mental representations that reflect who... https://www.jove.com/v/11038 136 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11040.jpg Self-Evaluation: Self-Enhancement and Self-Verification Social psychologists have documented that feeling good about ourselves and maintaining positive self-esteem is a powerful motivator of human behavior (Tavris & Aronson, 2008). In the United States, members of the predominant culture typically think very highly of themselves and view themselves as good people who are above average on many desirable traits (Ehrlinger, Gilovich, & Ross, 2005). Often, our behavior, attitudes, and beliefs are affected when we experience a threat to our... https://www.jove.com/v/11040 180 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18574.jpg Self-Concept Self-concept is the cognitive and emotional understanding individuals hold about their identity. It evolves through various developmental stages, beginning in infancy and maturing as children grow. This concept influences how individuals perceive their abilities, interact with others, and manage challenges throughout life. Infancy and Emerging Recognition During infancy, self-concept is virtually nonexistent. Babies do not distinguish themselves as separate entities and often mistake their... https://www.jove.com/v/18574 79 JoVE no https://cloudfront.jove.com/files/ftp_upload/19871/19871_article_thumb_19871.jpg Understanding the Self The self is a central aspect of human identity, encompassing an individual’s beliefs, emotions, perceptions, and experiences. It is a cognitive and psychological construct that enables individuals to interpret their traits and behaviors, influencing how they perceive themselves and interact with the world. While personality consists of stable and enduring characteristics, the self is shaped by self-perception and social experiences. This distinction highlights the dynamic nature of the self,... https://www.jove.com/v/19871 88 2025-09-18T17:24:27+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19872/19872_article_thumb_19872.jpg Understanding Self-Concept The self-concept encompasses individuals' beliefs about themselves, structured through cognitive frameworks known as self-schemas. These schemas function as mental representations of specific traits or behaviors, influencing how self-relevant information is perceived, processed, and remembered. For example, individuals who are schematic for body weight are more likely to interpret routine experiences—such as dining out or shopping—through the lens of that trait. Conversely, those aschematic for... https://www.jove.com/v/19872 80 2025-09-18T17:24:27+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54784.jpg Creating Virtual-hand and Virtual-face Illusions to Investigate Self-representation Here, we describe virtual-hand and virtual-face illusion paradigms that can be used to study body-related self-perception/-representation. They have already been used in various studies to demonstrate that, under specific conditions, a virtual hand or face can be incorporated into one's body representation, suggesting that body representations are rather flexible. https://www.jove.com/v/54784 413 2017-03-01T18:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61755.jpg Virtual Hand with Ambiguous Movement between the Self and Other Origin: Sense of Ownership and 'Other-Produced' Agency While previous research on bodily self-consciousness assumed that self- and other-origin movements were perceptually distinguishable, this protocol allows them to be ambiguous on a virtual hand with unintentional slight movements. This enables us to observe one’s experience formed by SoO and other-produced SoA, rather than the absence of SoA. https://www.jove.com/v/61755 481 2020-10-28T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65927.jpg A Modified Mirror Test as a Visual Guide for the Self-awareness Trait in Wild Antarctica Penguins, Pygoscelis adeliae A specially devised Modified Mirror Test has been used to find the traits of self-awareness in wild Adelie penguins. The experiment, conducted in different terrains of Antarctica during January-February 2020, is probably the first attempt to report the presence of these characteristics in penguins. https://www.jove.com/v/65927 291 2025-07-08T20:50:00+00:00 JoVE no https://visualize.jove.com/910084-cardio-respiratory-synchronisms-synchrony-with-artificial-circulation monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10887.jpg The Cardiac Cycle The heart beats rhythmically in a sequence called the cardiac cycle—a rapid coordination of contraction (systole) and relaxation (diastole). The Process Electrical signals—sent from the sinoatrial (SA) node in the right atrial wall to the atrioventricular (AV) node between the right atrium and right ventricle—cause both atria to simultaneously contract. When the signal reaches the AV node, it pauses for approximately a tenth of a second, allowing the atria to contract and empty blood into the... https://www.jove.com/v/10887 73 2025-10-23T18:49:10+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15270.jpg Overview of Systemic and Pulmonary Circulation The systemic and pulmonary circuits are crucial components of the circulatory system, working together to transport blood between the heart, lungs, and the rest of the body. The process begins with pulmonary circulation, where deoxygenated blood is pumped from the right ventricle to the lungs via the pulmonary trunk and arteries. Upon reaching the lungs, the blood becomes oxygenated and returns to the heart, specifically to the left atrium, via the pulmonary veins. The oxygenated blood is sent... https://www.jove.com/v/15270 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15274.jpg Cardiac Cycle The cardiac cycle refers to the sequence of events that occur in the heart from the beginning of one heartbeat to the next. It's characterized by alternating periods of contraction (systole) and relaxation (diastole) of the heart muscles. During the cardiac cycle, blood flow through the heart is regulated entirely by changing pressure gradients. This sequence of events begins with the heart in a state of total relaxation, known as mid-to-late diastole, during which blood passively flows from... https://www.jove.com/v/15274 89 2025-05-15T16:13:32+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15275.jpg Correlation between ECG and Cardiac Cycle The electrical signals recorded on an electrocardiogram (ECG) occur before the mechanical processes of contraction and relaxation during the cardiac cycle. A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before... https://www.jove.com/v/15275 85 2025-05-15T16:16:28+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/15283/15283_article_thumb_15283.jpg Imbalances in Cardiac Output The heart's primary function is to pump blood throughout the body, maintaining a balance between blood sent out (cardiac output) and blood returning (venous return). If this balance is disrupted, it can result in congestive heart failure (CHF), a severe condition where the heart becomes an inefficient pump, leading to inadequate blood circulation. CHF can occur due to the failure of either side of the heart. Left-side failure leads to pulmonary congestion—the right side continues to send blood... https://www.jove.com/v/15283 86 2025-05-15T16:19:11+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17947/17947_article_thumb_17947.jpg Cardiopulmonary Resuscitation II: ACLS Airway Management Airway management is a key skill in emergency and critical care settings, as maintaining a clear airway is essential for adequate oxygenation and ventilation.Head Tilt-Chin Lift TechniqueThe head tilt-chin lift maneuver is an essential technique primarily used in patients without suspected cervical spine injuries. To perform this maneuver, one hand is placed on the patient’s forehead, and gentle pressure is applied backward to tilt the head. The fingertips of the other hand are positioned under... https://www.jove.com/v/17947 82 2025-06-19T16:38:19+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50377.jpg Implantation of the Syncardia Total Artificial Heart The purpose of this manuscript is to briefly review indications, management, and outcomes for the total artificial heart. Video operative techniques for device implantation are presented. https://www.jove.com/v/50377 971 2014-07-18T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55961.jpg Use of Two Intracorporeal Ventricular Assist Devices As a Total Artificial Heart Here, we present a protocol using two centrifugal pumps as a total artificial heart replacement. https://www.jove.com/v/55961 529 2018-05-11T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56439.jpg Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing The establishment of a chronic asynchronous heart failure (HF) model by rapid pacing combined with left bundle branch ablation is presented. Two-dimensional speckle tracking imaging and aortic velocity time integral are applied to validate this stable HF model with left ventricular asynchrony and the benefits of cardiac resynchronization therapy. https://www.jove.com/v/56439 765 2017-12-11T21:00:00+00:00 JoVE no https://visualize.jove.com/1030604-automation-in-analysis-vii-automatic-mineralization-and-determination-of-organic-phosphorus monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2660.jpg High-Throughput Measurement and Classification of Organic P in Environmental Samples This protocol describes a high-throughput method of enzymatic hydrolysis that utilizes a microplate reader to measure and classify soil phosphorus as P monoesters, P diesters and inorganic P. Up to 96 samples can be measured at one time in a standard laboratory. https://www.jove.com/v/2660 538 2011-06-08T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14731.jpg Gravimetry: Inorganic And Organic Precipitating Agents In gravimetry, the precipitant is chosen carefully to obtain a pure solid that can be easily filtered. Common inorganic precipitants can be used to determine several cations and anions. In some cases, the formation of the same precipitate can be used to determine the cation and the anion. For example, the reaction of barium and chromate ions to give barium chromate is used to determine both barium and chromate. However, precipitates such as hydroxides, oxalates, and metal ammonium phosphates... https://www.jove.com/v/14731 49 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14776.jpg Sample Preparation for Analysis: Advanced Techniques Accurate analysis of complex samples often requires advanced preparation techniques to achieve reliable and reproducible results. Samples containing inorganic or organic materials can be challenging to dissolve or decompose effectively. Standard sample preparation methods include acid digestion, fusion, dry ashing, and wet digestion. Acid digestion with strong acids is commonly used to dissolve inorganic materials that are insoluble (do not dissolve) in water. This method can be useful for... https://www.jove.com/v/14776 68 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14807.jpg Photoluminescence: Applications Photoluminescence offers a wide range of applications due to its inherent sensitivity and selectivity. This technique allows for both direct and indirect analyses of the analyte. Direct quantitative analysis is possible when the analyte exhibits a favorable quantum yield for fluorescence or phosphorescence. However, an indirect analysis may be feasible if the analyte is not fluorescent or phosphorescent, or if the quantum yield is unfavorable. Indirect methods include reacting the analyte with... https://www.jove.com/v/14807 74 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57618.jpg Optimized Procedure for Determining the Adsorption of Phosphonates onto Granular Ferric Hydroxide using a Miniaturized Phosphorus Determination Method This paper introduces a procedure to investigate the adsorption of phosphonates onto iron-containing filter materials, particularly granular ferric hydroxide, with little effort and high reliability. In a buffered solution, the phosphonate is brought into contact with the adsorbent using a rotator and then analyzed via a miniaturized phosphorus determination method. https://www.jove.com/v/57618 501 2018-05-18T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58818.jpg Assaying for Inorganic Polyphosphate in Bacteria We describe a simple method for rapid quantification of inorganic polyphosphate in diverse bacteria, including Gram-negative, Gram-positive, and mycobacterial species. https://www.jove.com/v/58818 440 2019-01-21T23:00:00+00:00 JoVE no https://visualize.jove.com/1201666-effects-of-varying-laboratory-conditions-on-behavioral-state-organization-in-two-and-eight-week-old-infants monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11020.jpg Naturalistic Observations If you want to understand how behavior occurs, one of the best ways to gain information is to simply observe the behavior in its natural context. However, people might change their behavior in unexpected ways if they know they are being observed. How do researchers obtain accurate information when people tend to hide their natural behavior? As an example, imagine that your professor asks everyone in your class to raise their hand if they always wash their hands after using the restroom. Chances... https://www.jove.com/v/11020 150 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55435.jpg Experience is Instrumental in Tuning a Link Between Language and Cognition: Evidence from 6- to 7- Month-Old Infants' Object Categorization At 3-4 months, listening to human and nonhuman primate vocalizations boosts infants' cognition; by 6 months, only human vocalizations exert this cognitive advantage. We describe an exposure manipulation that reveals the powerful shaping role of experience as infants specify which sounds to link to cognition and which to tune out. https://www.jove.com/v/55435 335 2017-04-19T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55596.jpg A Within-subjects Experimental Protocol to Assess the Effects of Social Input on Infant EEG This novel protocol is designed to assess the neural bases of social interaction in infants. The paradigm is designed to tease apart how various social inputs such as language, joint attention, and face-to-face interaction relate to infant neural activation. Infant EEG power is recorded during both social and nonsocial conditions. https://www.jove.com/v/55596 500 2017-05-03T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60537.jpg Fear Incubation Using an Extended Fear-Conditioning Protocol for Rats We describe an extended fear-conditioning protocol that produces overtraining and fear incubation in rats. This protocol entails a single training session with 25 tone-shock pairings (i.e., overtraining) and a comparison of conditioned freezing responses during context and cue tests 48 h (short-term) and 6 weeks (long-term) after training. https://www.jove.com/v/60537 818 2020-08-22T20:00:00+00:00 JoVE no https://visualize.jove.com/1219372-recognition-between-trnas-and-aminoacyl-trna-synthetases-of-different-specificities monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2498.jpg Isolation of Translating Ribosomes Containing Peptidyl-tRNAs for Functional and Structural Analyses A major impediment to biochemical analyses of ribosomes containing nascent peptidyl-tRNAs has been the presence of other ribosomes in the same samples, ribosomes not involved in the translation of the specific mRNA sequence being analyzed. We developed a simple methodology to purify, exclusively, the ribosomes containing the nascent peptidyl-tRNA of interest. https://www.jove.com/v/2498 679 2011-02-26T00:03:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11591.jpg Transfer RNA Synthesis One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases. Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with... https://www.jove.com/v/11591 156 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11595.jpg tRNA Activation Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the... https://www.jove.com/v/11595 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11597.jpg Improving Translational Accuracy Base complementarity between the three base pairs of mRNA codon and the tRNA anticodon is not a failsafe mechanism. Inaccuracies can range from a single mismatch to no correct base pairing at all. The free energy difference between the correct and nearly correct base pairs can be as small as 3 kcal/ mol. With complementarity being the only proofreading step, the estimated error frequency would be one wrong amino acid in every 100 amino acids incorporated. However, error frequencies observed in... https://www.jove.com/v/11597 127 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12557.jpg Types of RNA Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in regulating gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use. RNA Performs Diverse... https://www.jove.com/v/12557 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11591.jpg Transfer RNA Synthesis One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases. Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with... https://www.jove.com/v/12569 156 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11595.jpg tRNA Activation Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the... https://www.jove.com/v/13132 146 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54273.jpg Residue-specific Incorporation of Noncanonical Amino Acids into Model Proteins Using an Escherichia coli Cell-free Transcription-translation System An easy-to-use, cell-free expression protocol for the residue-specific incorporation of noncanonical amino acid analogs into proteins, including downstream analysis, is presented for medical, pharmaceutic, structural and functional studies. https://www.jove.com/v/54273 707 2016-08-01T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56212.jpg Quantification of the Abundance and Charging Levels of Transfer RNAs in Escherichia coli Here we present a method for directly measuring transfer RNA charging levels from purified Escherichia coli RNA as well as a way to compare relative levels of transfer RNA, or any other short RNA, across different samples based on the addition of spike-in cells expressing a reference gene. https://www.jove.com/v/56212 634 2017-08-22T21:00:00+00:00 JoVE no https://visualize.jove.com/1289412-double-stranded-rna-and-interferon-alpha-induce-transcription-through-different-molecular-mechanisms monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10800.jpg Types of RNA Overview Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use. RNA... https://www.jove.com/v/10800 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10800.jpg Types of RNA Overview Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use. RNA... https://www.jove.com/v/11580 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11629.jpg siRNA - Small Interfering RNAs Small interfering RNAs, or siRNAs, are short regulatory RNA molecules that can silence genes post-transcriptionally, as well as the transcriptional level in some cases. siRNAs are important for protecting cells against viral infections and silencing transposable genetic elements. In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the ATP-dependent... https://www.jove.com/v/11629 150 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12557.jpg Types of RNA Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in regulating gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use. RNA Performs Diverse... https://www.jove.com/v/12557 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12557.jpg Types of RNA Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in regulating gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use. RNA Performs Diverse... https://www.jove.com/v/13946 80 JoVE no https://cloudfront.jove.com/files/ftp_upload/40862/40862_article_thumb_40862.jpg Inhibitors of Viral Protein Synthesis Protein synthesis is indispensable for viral replication, as viruses lack the cellular machinery required for this process and must hijack the host's translational apparatus. In response, host cells deploy a critical innate immune defense involving interferons, specialized cytokines that play a central role in inhibiting viral propagation.Upon viral detection, infected cells release interferons that bind to receptors on adjacent uninfected cells, activating the JAK-STAT signaling pathway and... https://www.jove.com/v/40862 90 2026-03-12T20:36:03+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52650.jpg High-throughput Quantitative Real-time RT-PCR Assay for Determining Expression Profiles of Types I and III Interferon Subtypes This protocol describes a high-throughput qRT-PCR assay for the analysis of type I and III IFN expression signatures. The assay discriminates single base pair differences between the highly similar transcripts of these genes. Through batch assembly and robotic pipetting, the assays are consistent and reproducible. https://www.jove.com/v/52650 600 2015-03-24T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54486.jpg Evaluation of the Efficacy And Toxicity of RNAs Targeting HIV-1 Production for Use in Gene or Drug Therapy Methods to evaluate the efficacy and toxicity of RNA molecules targeting post-integration steps of the HIV-1 replication cycle are described. These methods are useful for screening new molecules and optimizing the format of existing ones. https://www.jove.com/v/54486 723 2016-09-05T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59095.jpg Confocal Imaging of Double-Stranded RNA and Pattern Recognition Receptors in Negative-Sense RNA Virus Infection Double-stranded RNA produced during RNA virus replication can be recognized by pattern recognition receptors to induce an innate immune response. For negative-sense RNA viruses, the interaction between the low-level dsRNA and PRRs remains unclear. We have developed a confocal microscopy method to visualize arenavirus dsRNA and PRR in individual cells. https://www.jove.com/v/59095 404 2019-01-26T23:00:00+00:00 JoVE no https://visualize.jove.com/1296728-electrophysiological-evaluation-of-human-consciousness-level-by-automated-fluctuation-analysis-of-human-high-frequency-eeg monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14942.jpg Brain Waves Brain waves are electrical signals generated by the neurons in the brain, which are regularly monitored to measure mental activities. Brain waves and their frequency ranges can be measured using an electroencephalogram or EEG. There are four main types of brain waves, each with distinct characteristics: • Alpha Waves – Alpha brain waves, between 8 and 13 Hz ( Hertz), occur when a person is relaxed with eyes closed. The alpha waves then disappear when one is concentrating on specific tasks. <br... https://www.jove.com/v/14942 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54908.jpg High-density Electroencephalographic Acquisition in a Rodent Model Using Low-cost and Open-source Resources Instructions for the low-cost construction and surgical implantation of a chronic transcranial high-density electroencephalographic montage into mice are provided. Signal recording, extraction, and processing techniques are also described. https://www.jove.com/v/54908 759 2016-11-26T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68062.jpg Transauricular Vagus Nerve Stimulation and Electroencephalographic Assessment in Disorders of Consciousness This protocol aims to provide novel methodological insights into non-invasive neurostimulation, specifically transauricular vagus nerve stimulation (taVNS), in patients with disorders of consciousness. Additionally, a clinical and electroencephalographic analysis protocol is proposed to assess the efficacy of the treatment in this cohort, along with the discussion of relevant ethical considerations. https://www.jove.com/v/68062 244 2025-07-11T22:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68743.jpg The Combination of Transcranial Alternating Current Stimulation and Electroencephalogram This protocol establishes a practical approach for combining HD-tACS with EEG to examine stimulation effects on neural oscillations during cognitive tasks, using theta-frequency stimulation in working memory as an exemplar. https://www.jove.com/v/68743 374 2025-10-10T21:43:00+00:00 JoVE no https://visualize.jove.com/1343521-the-lithium-test-test-of-endogenous-criteria monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3769.jpg The Tail Suspension Test The tail-suspension test is validated as an experimental procedure to assess antidepressant efficacy of drug treatments in mice. Mice are suspended by their tails for six minutes and escape-related behaviors are assessed. We describe procedures used in conducting the tail suspension test. https://www.jove.com/v/3769 617 2012-01-29T05:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14577.jpg Effects of EDTA on End-Point Detection Methods Different methods, such as visual observance of metal-ion indicators, spectroscopic techniques, and potentiometric methods, can determine the endpoint of an EDTA titration. In the visual method, metal-ion indicators (metallochromic dyes), which have distinct colors in their free and complex forms, are added to the mixture to signal the titration's end point. They form stable complexes with metal ions, but these complexes are weaker than the corresponding metal–EDTA complexes. As a result, EDTA... https://www.jove.com/v/14577 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15197.jpg Mania and Antimanic Drugs: Overview Mania, a psychological condition characterized by elevated mood, increased energy, and reduced sleep need, is part of the bipolar disorder cycle. The exact cause of mania isn't entirely known, but it is thought to be a combination of genetic, environmental, and neurological factors. Bipolar disorder involves alternating manic and depressive episodes. Mood stabilizers like lithium, antipsychotics, and anticonvulsants help manage these episodes. Lithium carbonate is particularly effective as a... https://www.jove.com/v/15197 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54366.jpg 1,3,5-Triphenylbenzene and Corannulene as Electron Receptors for Lithium Solvated Electron Solutions The authors report on conductivity studies carried out on lithium solvated electron solutions (LiSES) prepared using 1,3,5-triphenylbenzene (TPB) and corannulene as electron receptors. https://www.jove.com/v/54366 416 2016-10-10T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57375.jpg In Situ Lithiated Reference Electrode: Four Electrode Design for In-operando Impedance Spectroscopy The incorporation of reference electrodes in a Li-ion battery provides valuable information to elucidate degradation mechanisms at high voltages. In this article, we present a cell design that accommodates multiple reference electrodes, along with the assembly steps to assure maximum accuracy of the data obtained in electrochemical measurements. https://www.jove.com/v/57375 576 2018-09-12T21:00:00+00:00 JoVE no https://visualize.jove.com/1363139-early-response-gene-induction-in-astrocytes-as-a-mechanism-for-encoding-and-integrating-neuronal-signals monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/51458.jpg Inducing Plasticity of Astrocytic Receptors by Manipulation of Neuronal Firing Rates Here we describe an adaptation of protocols used to induce homeostatic plasticity in neurons for the study of plasticity of astrocytic G protein-coupled receptors. Recently used to examine changes in astrocytic group I mGluRs in juvenile mice, the method can be applied to measure scaling of various astrocytic GPCRs, in tissue from adult mice in situ and in vivo, and to gain a better appreciation of the sensitivity of astrocytic receptors to changes in neuronal activity. https://www.jove.com/v/51458 767 2014-03-21T02:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51972.jpg Imaging Intracellular Ca 2+ Signals in Striatal Astrocytes from Adult Mice Using Genetically-encoded Calcium Indicators The properties and functions of astrocyte intracellular Ca2+ signals in the striatum remain incompletely explored. We describe methods to express genetically encoded calcium indicators in striatal astrocytes using adeno-associated viruses of serotype 2/5 (AAV2/5), as well as procedures to reliably image Ca2+ signals within striatal astrocytes in situ. https://www.jove.com/v/51972 739 2014-11-19T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58116.jpg Analyzing the Size, Shape, and Directionality of Networks of Coupled Astrocytes Here we present a protocol to assess the organization of astrocytic networks. The described method minimizes bias to provide descriptive measures of these networks such as cell count, size, area, and position within a nucleus. Anisotropy is assessed with a vectorial analysis. https://www.jove.com/v/58116 610 2018-10-04T20:00:00+00:00 JoVE no https://visualize.jove.com/1393562-a-two-trial-memory-task-with-automated-recording-study-in-young-and-aged-rats monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/51316.jpg Automated Visual Cognitive Tasks for Recording Neural Activity Using a Floor Projection Maze We describe protocols for training rats for chronic electrophysiological recordings in fully automated cognitive tasks on a Floor Projection Maze. https://www.jove.com/v/51316 675 2014-02-21T06:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58009.jpg Automated, Long-term Behavioral Assay for Cognitive Functions in Multiple Genetic Models of Alzheimer's Disease, Using IntelliCage This paper describes a protocol for cognitive assessments for genetic models of the Alzheimer's disease using the IntelliCage system, which is a high throughput automated behavioral monitoring system with operant conditioning. https://www.jove.com/v/58009 406 2018-08-04T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61494.jpg Simultaneous Monitoring of Wireless Electrophysiology and Memory Behavioral Test as a Tool to Study Hippocampal Neurogenesis The protocol presented here provides information on the simultaneous electroencephalography (EEG) and behavioral assessment in real-time. We have discussed all steps involved in this protocol as an attractive solution for researchers in many fields of neuroscience, particularly in learning and memory areas. https://www.jove.com/v/61494 445 2020-08-20T20:00:00+00:00 JoVE no https://visualize.jove.com/1428759-argyrophylic-nucleolar-organiser-regions-agnors-as-a-prognostic-indicator-in-breast-carcinoma monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11592.jpg The Nucleolus The nucleolus is the most prominent substructure of the nucleus. When it was first discovered, it was considered to be an isolated organelle that forms fibrils and granules. In 1931, the relationship between the nucleolus and chromosomes was first described by Heitz. He observed that the appearance and size of nucleolus varies depending on the stage of the cell cycle. He also noticed constricted regions on different chromosomes clustered together at definite cell cycle stages. These regions,... https://www.jove.com/v/11592 175 JoVE no https://cloudfront.jove.com/files/ftp_upload/19476/19476_article_thumb_19476.jpg Nucleoid The nucleoid represents a structurally and functionally distinct region within prokaryotic cells, where the cell's DNA and associated proteins are housed. Unlike eukaryotic cells, prokaryotes lack a membrane-bound nucleus, and the nucleoid facilitates the organization and accessibility of the genetic material within this constraint. The DNA in most bacteria and archaea exists as a single, circular, double-stranded molecule that is highly compacted through supercoiling and interactions with... https://www.jove.com/v/19476 84 2025-06-12T16:31:54+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55043.jpg A Model for Perineural Invasion in Head and Neck Squamous Cell Carcinoma Perineural invasion (PNI) is a common feature of head and neck squamous cell carcinoma (HNSCC), conferring lower survival rates. Its mechanisms are poorly understood. Utilizing neurites generated from murine dorsal root ganglia confined to a semisolid matrix, the pathways involved in the PNI of HNSCC cell lines can be investigated. https://www.jove.com/v/55043 539 2017-01-05T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57148.jpg Optimization of a Multiplex RNA-based Expression Assay Using Breast Cancer Archival Material Nucleic acid degradation in archival tissue, tumor heterogeneity, and a lack of fresh frozen tissue specimens can negatively impact cancer diagnostic services in pathology laboratories worldwide. This manuscript describes the optimization of a panel of biomarkers using a multiplex magnetic bead assay to classify breast cancers. https://www.jove.com/v/57148 672 2018-08-01T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59238.jpg Performing Data Mining And Integrative Analysis Of Biomarker in Breast Cancer Using Multiple Publicly Accessible Databases Here, we present a protocol to explore the biomarker and survival predictor of breast cancer based on the comprehensive analysis of pooled clinical datasets derived from a variety of publicly accessible databases, using the strategy of expression, correlation and survival analysis step by step. https://www.jove.com/v/59238 461 2019-05-17T20:00:00+00:00 JoVE no https://visualize.jove.com/1459664-intensive-respiratory-care-service-our-eight-year-experience monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13835.jpg Respiratory Assessment: Purpose and Indications Respiratory assessment is a cornerstone of nursing assessments, crucial for the early detection of patient deterioration. This evaluation transcends routine procedures, representing a critical skill nurses must master to ensure optimal patient care. Objectives and Importance: The primary goal of respiratory assessment is to evaluate patients at early risk of clinical deterioration. Since respiratory distress often precedes other signs of declining health, breathing patterns and sounds become a... https://www.jove.com/v/13835 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16349.jpg Acute Respiratory Failure-I Acute respiratory failure is a condition characterized by the inability of the lungs to perform their primary function: gas exchange. This failure leads to insufficient oxygen levels (hypoxemia) in the blood, elevated carbon dioxide levels (hypercapnia), or both, causing critical impairment in organ function. Definition: It is defined by specific criteria based on blood gas measurements. Hypoxemia happens when the partial pressure of oxygen (PaO2) falls below 60 mmHg. At the same time,... https://www.jove.com/v/16349 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16350.jpg Acute Respiratory Failure-II Type I Respiratory Failure, or hypoxemic respiratory failure, occurs when the partial pressure of oxygen (PaO2) in arterial blood falls below 60 mmHg while breathing room air without a corresponding increase in arterial carbon dioxide levels (PaCO2). This condition highlights a significant impairment in the lungs' capacity to oxygenate the blood. The underlying physiological abnormalities that contribute to hypoxemic respiratory failure include: • Ventilation-Perfusion (V/Q) Mismatch: The... https://www.jove.com/v/16350 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16351.jpg Acute Respiratory Failure-III Hypercapnic respiratory failure, also known as Type 2 or ventilatory respiratory failure, is a severe condition characterized by the body's inability to effectively remove carbon dioxide (CO2) from the bloodstream. It leads to an arterial CO2 pressure (PaCO2) exceeding 45 mmHg and a blood pH above 7.35. This situation indicates that the body's ventilatory demand, or the ventilation needed to maintain normal PaCO2 levels, surpasses its supply or the maximum gas flow achievable without causing... https://www.jove.com/v/16351 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16352.jpg Acute Respiratory Failure-IV Respiratory failure can manifest suddenly or gradually, characterized by a rapid decline in PaO2 and a rapid rise in PaCO2. This situation indicates a severe respiratory problem that may quickly become a life-threatening emergency. One of the early signs of hypoxemic Acute Respiratory Failure (ARF) is a change in mental status due to the brain's sensitivity to oxygen levels and changes in acid-base balance. Symptoms such as restlessness, confusion, and agitation suggest inadequate oxygen... https://www.jove.com/v/16352 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16353.jpg Acute Respiratory Failure-V The treatment for acute respiratory failure varies based on factors like the underlying cause, overall health, and severity. A collaborative healthcare team is essential for early detection, often through arterial blood gas analysis. Identifying the cause is the primary goal, with treatment strategies adjusted for ventilation/perfusion (V/Q) mismatch, shunting, or diffusion impairment. Ensure that patients are monitored continuously for their response to therapy, including changes in... https://www.jove.com/v/16353 89 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63243.jpg Conducting Respiratory Oscillometry in an Outpatient Setting We demonstrate a standard operating protocol to conduct respiratory oscillometry, highlighting key quality control and assurance procedures. https://www.jove.com/v/63243 889 2022-04-08T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66059.jpg Microbiological Rapid On-Site Evaluation for Pulmonary Infectious Diseases The protocol here demonstrates a fast and standardized microbiological rapid on-site evaluation (M-ROSE) workflow, including three steps: slide making, staining, and interpretation. This protocol will help physicians make rapid clinical decisions. https://www.jove.com/v/66059 202 2024-03-01T21:40:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66756.jpg Monitoring Lung Function with Electrical Impedance Tomography in the Intensive Care Unit Electrical Impedance Tomography is a non-invasive, radiation-free, real-time pulmonary ventilation monitoring tool. By measuring impedance changes in the thorax, it can visualize the distribution of air on a breath-by-breath basis. Initially intended for ventilation monitoring, electrical impedance tomography can also measure perfusion via intravenous injection of a saline solution. https://www.jove.com/v/66756 356 2024-09-06T20:10:00+00:00 JoVE no https://visualize.jove.com/1479891-identification-of-functional-regions-of-the-positively-acting-regulatory-gene-amdr-from-aspergillus-nidulans monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11609.jpg Prokaryotic Transcriptional Activators and Repressors The organization of prokaryotic genes in their genome is notably different from that of eukaryotes. Prokaryotic genes are organized, such that the genes for proteins involved in the same biochemical process or function are located together in groups. This group of genes, along with their regulatory elements, are collectively known as an operon. The functional genes in an operon are transcribed together to give a single strand of mRNA known as polycistronic mRNA. Transcription of prokaryotic... https://www.jove.com/v/11609 118 JoVE no https://cloudfront.jove.com/files/ftp_upload/19540/19540_article_thumb_19540.jpg Gene Regulation During Sporulation Sporulation is a complex developmental process that allows certain Gram-positive bacteria, such as Bacillus subtilis and Clostridium species, to survive extreme environmental conditions. This process is tightly regulated by a series of signaling cascades and transcriptional controls, ensuring the formation of a highly resistant endospore.Sporulation is triggered by unfavorable conditions, such as nutrient depletion, and is governed by a phosphorelay system. One of the sensor kinases, such as... https://www.jove.com/v/19540 77 2025-06-12T16:15:48+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51715.jpg DNA-affinity-purified Chip (DAP-chip) Method to Determine Gene Targets for Bacterial Two component Regulatory Systems This video article describes an in vitro microarray based method to determine the gene targets and binding sites for two component system response regulators. https://www.jove.com/v/51715 744 2014-07-21T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59169.jpg Inhibition of Aspergillus flavus Growth and Aflatoxin Production in Transgenic Maize Expressing the α-amylase Inhibitor from Lablab purpureus L. Here we present a protocol to analyze Aspergillus flavus growth and aflatoxin production in maize kernels expressing an antifungal protein. Using a GFP-expressing A. flavus strain we monitored the infection and spread of the fungus in mature kernels in real time. The assay is rapid, reliable, and reproducible. https://www.jove.com/v/59169 561 2019-02-15T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62778.jpg Quantitative Analysis of Aspergillus nidulans Growth Rate using Live Microscopy and Open-Source Software We present a label-free live imaging protocol using transmitted light microscopy techniques to capture images, analyze and quantify growth kinetics of the filamentous fungus A. nidulans in both submerged cultures and solid media. This protocol can be used in conjunction with fluorescence microscopy. https://www.jove.com/v/62778 690 2021-07-24T22:00:00+00:00 JoVE no https://visualize.jove.com/1504625-mammalian-artificial-chromosomes monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11002.jpg X-Inactivation The human X chromosome contains over ten times the number of genes as in the Y chromosome. Since males have only one X chromosome, and females have two, one might expect females to produce twice as many of the proteins, with undesirable results. Instead, in order to avoid this potential issue, female mammalian cells inactivate nearly all the genes in one of their X chromosomes during early embryonic development. In the nuclear envelope surrounding the cell nucleus, the inactivated X chromosome... https://www.jove.com/v/11002 118 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11539.jpg Lampbrush Chromosomes In 1882, Flemming observed lampbrush chromosomes (LBC) in salamander eggs. Later in 1892, Rückert observed LBCs in shark egg cells and coined the term "lampbrush chromosomes" because they looked like brushes used to clean kerosene lamps. LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops resemble the... https://www.jove.com/v/11539 111 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53164.jpg Bacterial Artificial Chromosomes: A Functional Genomics Tool for the Study of Positive-strand RNA Viruses Here, a protocol is presented for creating an infectious bacterial artificial chromosome containing a full-length cDNA of the positive-strand genomic RNA of Japanese encephalitis virus. This protocol can be used to construct a functional cDNA of other positive-strand RNA viruses, making it a powerful genomic tool for studying virus biology. https://www.jove.com/v/53164 740 2015-12-29T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59375.jpg Chromatin Immunoprecipitation Assay Using Micrococcal Nucleases in Mammalian Cells Chromatin immunoprecipitation (ChIP) is a powerful tool for understanding the molecular mechanisms of gene regulation. However, the method involves difficulties in obtaining reproducible chromatin fragmentation by mechanical shearing. Here, we provide an improved protocol for a ChIP assay using enzymatic digestion. https://www.jove.com/v/59375 702 2019-05-10T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61147.jpg Lineage Tracing and Clonal Analysis in Developing Cerebral Cortex Using Mosaic Analysis with Double Markers (MADM) A protocol to perform lineage tracing and functional genetic analysis of candidate genes at a single cell level using mosaic analysis with double markers (MADM) is presented. MADM clonal analysis provides a quantitative framework to measure the proliferative behavior, cellular output, and lineage relationship of individual progenitors and their daughter cells. https://www.jove.com/v/61147 565 2020-05-08T21:30:00+00:00 JoVE no https://visualize.jove.com/1507168-chromosome-analysis-by-image-processing-in-a-computerized-environment-clinical-applications monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3887.jpg Spectral Karyotyping to Study Chromosome Abnormalities in Humans and Mice with Polycystic Kidney Disease Spectral Karyotyping (SKY) is an advanced cytogenetics technique to identify genomic and chromosomal aberrations. This technique takes advantage of chromosome painting probes, which allow classification of all chromosomes. SKY can also identify complex chromosome aberrations and segregation defects in mice and humans with various diseases, including polycystic kidney disease. https://www.jove.com/v/3887 767 2012-02-03T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/4007.jpg High-throughput Physical Mapping of Chromosomes using Automated in situ Hybridization Genome assemblies based on massively parallel DNA sequencing technologies are usually highly fragmented. The development of physical chromosome maps can potentially improve genome assemblies. Here, we demonstrate innovative approaches to chromosome preparation, fluorescent in situ hybridization, and imaging that significantly increase throughput of the physical map development. https://www.jove.com/v/4007 528 2012-06-28T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/10787/10787_article_thumb_10787.jpg Karyotyping Describing the number and physical features of chromosomes can reveal abnormalities that underlie genetic diseases. This description is facilitated by special staining techniques that produce a particular banding pattern on each chromosome. State-of-the-art techniques make this approach even more powerful, enabling the detection of individual genes that cause disease.A Simple Chromosome Staining Technique Provides Valuable Scientific InsightSome genetic diseases can be detected by looking at... https://www.jove.com/v/10787 77 2026-06-01T13:28:21+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56245.jpg Expedited Radiation Biodosimetry by Automated Dicentric Chromosome Identification (ADCI) and Dose Estimation The cytogenetic dicentric chromosome (DC) assay quantifies exposure to ionizing radiation. The Automated Dicentric Chromosome Identifier and Dose Estimator software accurately and rapidly estimates biological dose from DCs in metaphase cells. It distinguishes monocentric chromosomes and other objects from DCs, and estimates biological radiation dose from the frequency of DCs. https://www.jove.com/v/56245 633 2017-09-04T20:00:00+00:00 JoVE no https://visualize.jove.com/1511606-development-of-an-expert-system-advisor-for-anaesthetic-control monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14748.jpg Local Anesthetics: Clinical Application as Epidural Anesthesia Epidural anesthetics are administered in the fat-filled epidural space, the outermost part of the spinal canal. This technique is commonly employed for pain management and anesthesia during lower abdomen and pelvis surgeries or labor and delivery. Since epidural anesthetics can be infused through an epidural catheter, all types of drugs, including short-acting ones, can be administered. Chloroprocaine and lidocaine are examples of short and long-duration anesthetics, respectively. Bupivacaine... https://www.jove.com/v/14748 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14749.jpg Local Anesthetics: Clinical Application as Intravenous Regional Anesthesia Intravenous regional anesthesia or the Bier block technique is used to anesthetize a specific limb or extremity. It uses exsanguinated or blood-drained vessels to transport local anesthetics or LAs to the peripheral nerve trunks. Lidocaine without vasoconstrictors like epinephrine is most commonly used for this technique. Other drugs used are prilocaine, ropivacaine, and chloroprocaine. Bupivacaine is not recommended for this technique due to its high cardiac toxicity. One of the advantages of... https://www.jove.com/v/14749 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15188.jpg General Anesthesia: Overview Anesthesia is a medical procedure that uses drugs for CNS suppression to enable painless surgeries and procedures. The selection of anesthetics is influenced by their pharmacokinetic properties, side effects, and patient characteristics. Various types of anesthesia include general, local, regional, spinal, and inhalational. General anesthesia induces unconsciousness in the whole body, while the others target specific areas or sensations. It is administered to minimize adverse effects, maintain... https://www.jove.com/v/15188 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15189.jpg Stages of General Anesthesia Various sedation levels offer significant advantages in facilitating procedural interventions for patients undergoing medical or invasive surgical procedures. These levels span from anxiolysis to general anesthesia, providing a spectrum of sedative effects to cater to specific patient needs. Anxiolysis reduces anxiety and is achieved through minimal sedation, enabling patients to remain awake and responsive while feeling more at ease during the procedure. This level can benefit minor... https://www.jove.com/v/15189 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15190.jpg Parenteral Anesthetics: Overview Intravenous anesthetics are drugs administered parenterally to induce anesthesia or sedation. Propofol is a widely used agent formulated as a 1% emulsion in soybean oil, glycerol, and egg phosphatide. It induces rapid anesthesia primarily due to its rapid distribution from the bloodstream to target tissues and is metabolized in the liver. However, it can cause significant pain on injection and hypertriglyceridemia. Fospropofol, a water-based prodrug of propofol, lacks these adverse effects. https://www.jove.com/v/15190 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16031.jpg Control Systems Control systems are everywhere in contemporary society, influencing diverse applications from aerospace to automated manufacturing. These systems can be found naturally within biological processes, such as blood sugar regulation and heart rate adjustment in response to stress, as well as in man-made systems like elevators and automated vehicles. A control system is essentially a network of subsystems and processes that collaboratively convert specific inputs into desired outputs. At the heart... https://www.jove.com/v/16031 70 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51079.jpg Assessing Changes in Volatile General Anesthetic Sensitivity of Mice after Local or Systemic Pharmacological Intervention Loss of the righting reflex has long served as a standard behavioral surrogate for unconsciousness, also called hypnosis, in laboratory animals. Alterations in volatile anesthetic sensitivity caused by pharmacological interventions can be detected with a carefully controlled high-throughput assessment system, which may be adapted for delivery of any inhaled therapeutic. https://www.jove.com/v/51079 529 2013-10-17T04:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54436.jpg Use of a Low-flow Digital Anesthesia System for Mice and Rats Here, we present a protocol to more safely and efficiently administer anesthetic gas to mice using a digital, low flow anesthesia system utilizing a syringe-driven direct injection vaporizer. https://www.jove.com/v/54436 486 2016-09-07T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61311.jpg Use of an Integrated Low-Flow Anesthetic Vaporizer, Ventilator, and Physiological Monitoring System for Rodents Here, we present a protocol to safely and effectively administer anesthetic gas to mice using a digital, low flow anesthesia system with integrated ventilator and physiological monitoring modules. https://www.jove.com/v/61311 417 2020-07-09T20:00:00+00:00 JoVE no https://visualize.jove.com/1515485-behavioral-effects-of-adrenal-medullary-transplants-in-non-human-primates monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14987.jpg Hormones of the Adrenal Glands Adrenal hormones play a pivotal role in maintaining the body's electrolyte balance and orchestrating responses to stress, showcasing the intricate functions of the adrenal cortex and medulla. The adrenal cortex, a powerhouse of hormone synthesis, generates over two dozen corticosteroid hormones. The zona glomerulosa produces mineralocorticoids, exemplified by aldosterone, influencing the electrolyte composition of body fluids. The synthesis of glucocorticoids such as cortisol and corticosterone... https://www.jove.com/v/14987 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14988.jpg Adrenal Gland Disorders Adrenal gland disorders manifest when the production of adrenal hormones deviates from the norm, resulting in either excessive or insufficient concentrations. Adrenal insufficiency, characterized by insufficient cortisol and aldosterone production, leads to conditions like Addison's disease. This disorder, affecting the adrenal cortex, exhibits symptoms such as skin bronzing, dehydration, low blood pressure, fatigue, and weight loss. Congenital adrenal hyperplasia, a genetic ailment causing... https://www.jove.com/v/14988 87 JoVE no https://cloudfront.jove.com/files/ftp_upload/40896/40896_article_thumb_40896.jpg Cushing Syndrome II: Pathophysiology Cortisol production is normally governed by the hypothalamic–pituitary–adrenal (HPA) axis, which maintains hormonal balance through tightly regulated feedback mechanisms. Disruption of this regulatory system is central to the development of Cushing syndrome, whether the excess cortisol originates from external medications or internal pathology. Persistent cortisol elevation alters metabolism, immune function, and endocrine signaling, producing the characteristic clinical features of the... https://www.jove.com/v/40896 79 2026-04-13T21:37:37+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58933.jpg Preparation and Gene Modification of Nonhuman Primate Hematopoietic Stem and Progenitor Cells The goal of this protocol is to isolate nonhuman primate CD34+ cells from primed bone marrow, to gene-modify these cells with lentiviral vectors, and to prepare a product for infusion into the autologous host. The total protocol length is approximately 48 h. https://www.jove.com/v/58933 676 2019-02-15T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59016.jpg Primary Culture of Rat Adrenocortical Cells and Assays of Steroidogenic Functions The hormone secreted by the adrenal cortex is vital for animals against stress and diseases. Here, we present a protocol to culture the primary rat adrenal cells. It could be a good in vitro platform for investigating the mechanisms of the reagent of interest in adrenal steroidogenesis and lipid biosynthesis. https://www.jove.com/v/59016 273 2019-03-12T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67387.jpg Restraint to Induce Stress in Mice and Rats This article covers the procedures to induce stress responses using physical restraint stress in mice and rats. Additional considerations that should be observed when selecting and using restraint stress in rodent models are discussed. https://www.jove.com/v/67387 228 2024-12-06T22:00:00+00:00 JoVE no https://visualize.jove.com/1562604-expression-and-aggregation-of-recombinant-alpha-a-crystallin-and-its-two-domains monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4204.jpg Purification and Aggregation of the Amyloid Precursor Protein Intracellular Domain A method for large-scale purification of the APP intracellular domain (AICD) is described. We also describe methodology to induce in vitro AICD aggregation and visualization by atomic force microscopy. The methods described are useful for biochemical/structural characterization of the AICD and the effects of molecular chaperones on its aggregation. https://www.jove.com/v/4204 608 2012-08-28T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10678.jpg Protein Organization Overview Proteins are one of the fundamental building blocks of life that carry out many diverse functions in the cell. Proteins are assembled from amino acids. The sequence of amino acids is known as the primary structure of a protein. Local interactions of individual amino acids cause the linear chain to fold into the secondary structures. Interactions of distant amino acids lead to further folding of the protein—the tertiary structure. The assembly of multiple folded chains (subunits) is... https://www.jove.com/v/10678 73 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10679.jpg Protein Folding Overview Proteins are chains of amino acids linked together by peptide bonds. Upon synthesis, a protein folds into a three-dimensional conformation which is critical to its biological function. Interactions between its constituent amino acids guide protein folding, and hence the protein structure is primarily dependent on its amino acid sequence. Protein Structure Is Critical to Its Biological Function Proteins perform a wide range of biological functions such as catalyzing chemical... https://www.jove.com/v/10679 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10898.jpg Antibody Structure Overview Antibodies, also known as immunoglobulins (Ig), are essential players of the adaptive immune system. These antigen-binding proteins are produced by B cells and make up 20 percent of the total blood plasma by weight. In mammals, antibodies fall into five different classes, which each elicits a different biological response upon antigen binding. The Y-Shaped Structure of Antibodies Consists of Four Polypeptide Chains Antibodies consist of four polypeptide chains: two identical heavy... https://www.jove.com/v/10898 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11503.jpg Conservation of Protein Domains Over Different Proteins Protein domains are small structurally independent units that are part of a single amino acid chain. Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms. A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form... https://www.jove.com/v/11503 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12488.jpg Protein Folding Proteins are chains of amino acids linked together by peptide bonds. Upon synthesis, a protein folds into a three-dimensional conformation, critical to its biological function. Interactions between its constituent amino acids guide protein folding, and hence the protein structure is primarily dependent on its amino acid sequence. Protein Structure Is Critical to Its Biological Function Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing... https://www.jove.com/v/12488 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13902.jpg Globular Proteins In organisms, proteins are the most abundant macromolecules. They act as the building blocks of life and play various crucial roles in the body. Proteins can be broadly classified into two distinct subtypes based on their shape and solubilities: globular proteins and fibrous proteins. Globular proteins serve many important physiological functions, such as acting as enzymes, cellular messengers, and molecular transporters. These roles often require the proteins to be soluble in the aqueous... https://www.jove.com/v/13902 87 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54886.jpg Combining Wet and Dry Lab Techniques to Guide the Crystallization of Large Coiled-coil Containing Proteins We describe a framework incorporating straightforward biochemical and computational analysis to guide the characterization and crystallization of large coiled-coil domains. This framework can be adapted for globular proteins or extended to incorporate a variety of high-throughput techniques. https://www.jove.com/v/54886 674 2017-01-06T18:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65828.jpg ABCG5/G8 Crystallization in a Lipidic Bicelle Environment for X-Ray Crystallography This protocol describes a setup for the crystallization of the sterol transporter ABCG5/G8. ABCG5/G8 is reconstituted into bicelles for hanging-drop crystallization. The protocol does not require specialized materials or substrates, making it accessible and easy to adapt in any laboratory for determining the protein structure through X-ray crystallography. https://www.jove.com/v/65828 407 2023-08-25T21:40:00+00:00 JoVE no https://visualize.jove.com/1570958-patient-classification-systems-a-new-approach-to-computing-reliability monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13101.jpg Classification of Illness The meaning of illness is individualized to each person who experiences an alteration in health. In contrast, disease is a medical term indicating a pathological change in the structure and function of the body or mind. It is a condition that has specific symptoms and boundaries. An illness is a response to a disease in which the person's level of functioning is changed compared with a previous level. The general classification of illness includes acute and chronic. Acute illness is severe and... https://www.jove.com/v/13101 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13551.jpg Nursing Interventions II: Selecting and Classifying the Nursing Interventions Creating and executing a nursing diagnosis helps nurses plan care and guide patient, family, and community interventions. They are developed based on a patient's physical evaluation and support measuring the outcomes. It is not recommended to select random interventions throughout the planning process. Instead, consider the following six essential factors when choosing interventions: Characteristics of the nursing diagnosis Goals and expected outcomes Evidence basis (e.g., research or... https://www.jove.com/v/13551 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14126.jpg Nursing Clinical Information System Nursing Clinical Information System (NCIS) A Nursing Clinical Information System (NCIS) is a specialized type of healthcare information system tailored to meet the unique needs of nursing practice. It incorporates the principles of nursing informatics to streamline information management and improve the quality of care delivery. Critical attributes of NCIS include: Efficient Information Management: NCIS is designed to manage patient information efficiently, making it easily accessible to... https://www.jove.com/v/14126 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16045.jpg Classification of Systems-I Linearity is a system property characterized by a direct input-output relationship, combining homogeneity and additivity. Homogeneity dictates that if an input x(t) is multiplied by a constant c, the output y(t) is multiplied by the same constant. Mathematically, this is expressed as: Additivity means that the response to the sum of multiple inputs is the sum of their individual responses. For inputs x1(t) and x2(t) producing outputs y1(t) and y2(t), respectively: Combining homogeneity and... https://www.jove.com/v/16045 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16046.jpg Classification of Systems-II Continuous-time systems have continuous input and output signals, with time measured continuously. These systems are generally defined by differential or algebraic equations. For instance, in an RC circuit, the relationship between input and output voltage is expressed through a differential equation derived from Ohm's law and the capacitor relation, Discrete-time systems have input and output signals at specific intervals, defined at distinct instants by difference equations. An example is a... https://www.jove.com/v/16046 91 JoVE no https://cloudfront.jove.com/files/ftp_upload/19555/19555_article_thumb_19555.jpg Microbial Classification System Classification is the process of organizing organisms into hierarchically inclusive groups based on their phenotypic similarities or evolutionary relationships. A species comprises one or more strains, and closely related species are grouped into genera. Genera are further classified into families, families into orders, orders into classes, and so forth, up to the domain level, which is the broadest taxonomic rank derived from a combination of phenotypic and genotypic data.The nomenclature of... https://www.jove.com/v/19555 84 2025-06-12T16:18:58+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59649.jpg A Machine Learning Approach to Design an Efficient Selective Screening of Mild Cognitive Impairment This methodology produces decision trees that target population groups more prone to suffering from mild cognitive impairment and are useful for cost-effective selective screening of the disease. https://www.jove.com/v/59649 738 2020-01-11T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59825.jpg Inverse Probability of Treatment Weighting (Propensity Score) using the Military Health System Data Repository and National Death Index When randomized controlled trials are not feasible, a comprehensive health care data source like the Military Health System Data Repository provides an attractive alternative for retrospective analyses. Incorporating mortality data from the national death index and balancing differences between groups using propensity weighting helps reduce biases inherent in retrospective designs. https://www.jove.com/v/59825 415 2020-01-08T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63848.jpg A Computer-Based Platform for Aiding Clinicians in Eating Disorder Analysis and Diagnosis Diagnosing eating disorders in healthcare is challenging. Therefore, the present protocol develops an algorithm based on 949 patient responses to a questionnaire, with the diagnosis displayed on an easy-to-use web-based interface. This system facilitates the accurate diagnosis of eating disorders while excluding those believed to have an eating disorder. https://www.jove.com/v/63848 259 2022-05-10T23:00:00+00:00 JoVE no https://visualize.jove.com/1574530-effects-of-amphetamine-and-nomifensine-on-intracranial-self-stimulation-discrimination-behavior-in-rats monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3798.jpg Single Cell Measurement of Dopamine Release with Simultaneous Voltage-clamp and Amperometry The amperometric technique measures dopamine release from a single cell by detecting the oxidative current produced by spontaneous dopamine oxidization. Simultaneous voltage clamp and amperometry methodology reveal the mechanistic relationship between the overall "activity" of dopamine transporter and the regulatory role of this activity on the reverse transport of... https://www.jove.com/v/3798 450 13300 2012-11-21T17:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53266.jpg A General Method for Evaluating Deep Brain Stimulation Effects on Intravenous Methamphetamine Self-Administration This article describes the delivery of intracranial electrical stimulation that is temporally and spatially separate from the drug-use environment for the treatment of IV methamphetamine... https://www.jove.com/v/53266 556 17600 2016-01-22T18:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60886.jpg Combined Infusion and Stimulation with Fast-Scan Cyclic Voltammetry CIS-FSCV to Assess Ventral Tegmental Area Receptor Regulation of Phasic Dopamine The goal of this protocol is to directly manipulate ventral tegmental area receptors to study their contribution to subsecond dopamine... https://www.jove.com/v/60886 400 2800 2020-04-23T18:00:00+00:00 JoVE no https://visualize.jove.com/1652432-adrenergic-and-cholinergic-regulation-of-cortisol-secretion-from-the-zona-fasciculatareticularis-of-bovine-adrenal-cortex monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10879.jpg Hypothalamic-Pituitary Axis The response to stress—be it physical or psychological, acute or chronic—involves activation of the Hypothalamic-Pituitary-Adrenal (HPA) axis. The HPA axis is part of the neuroendocrine system because it involves both neuronal and hormonal communication. Its function is to regulate homeostatic systems—metabolic, cardiovascular, and immune—providing the necessary means to respond to a stressor. What Happens During Stress In response to stress, the neurons in the hypothalamus release... https://www.jove.com/v/10879 97 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14465.jpg Adrenergic Receptors (Adrenoceptors): Classification Adrenergic receptors, or adrenoceptors, respond to the autonomic neurotransmitter noradrenaline and other endogenous catecholamine agonists. They are classified into two main families, α and β, based on their pharmacological response and are further subdivided depending on their location, elicited response, and affinity to specific agonists or antagonists. α-Adrenoceptors α-Adrenoceptors are classified into two main subtypes: α1 and α2. The α1 adrenoceptors, which are found on postsynaptic... https://www.jove.com/v/14465 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14467.jpg Adrenergic Receptors: β Subtype β-adrenoceptors have varied sensitivities towards adrenaline, noradrenaline, and isoprenaline. The order of agonist potency is as follows: Isoprenaline > Adrenaline > Noradrenaline Neurotransmitter binding to these receptors causes activation of adenylyl cyclase resulting in increased concentrations of cAMP and modulation of calcium ion channels within the cell. They are further classified into β1, β2, and β3 subtypes. β1-adrenoceptors: β1-adrenoceptors have equal affinities for... https://www.jove.com/v/14467 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14986.jpg Anatomy of the Adrenal Glands The adrenal or supra-renal glands, situated above the kidneys and aligned with the twelfth rib, are paired pyramid-shaped structures crucial for the body's stress response. During stress, these glands secrete hormones vital for adaptive physiological reactions. These glands possess a distinctive yellow tinge due to the stored cholesterol and fatty acids required for hormone synthesis. They are encased in a fibrous capsule and cushioned by fat. The adrenal gland comprises two distinct regions... https://www.jove.com/v/14986 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14987.jpg Hormones of the Adrenal Glands Adrenal hormones play a pivotal role in maintaining the body's electrolyte balance and orchestrating responses to stress, showcasing the intricate functions of the adrenal cortex and medulla. The adrenal cortex, a powerhouse of hormone synthesis, generates over two dozen corticosteroid hormones. The zona glomerulosa produces mineralocorticoids, exemplified by aldosterone, influencing the electrolyte composition of body fluids. The synthesis of glucocorticoids such as cortisol and corticosterone... https://www.jove.com/v/14987 91 JoVE no https://cloudfront.jove.com/files/ftp_upload/40896/40896_article_thumb_40896.jpg Cushing Syndrome II: Pathophysiology Cortisol production is normally governed by the hypothalamic–pituitary–adrenal (HPA) axis, which maintains hormonal balance through tightly regulated feedback mechanisms. Disruption of this regulatory system is central to the development of Cushing syndrome, whether the excess cortisol originates from external medications or internal pathology. Persistent cortisol elevation alters metabolism, immune function, and endocrine signaling, producing the characteristic clinical features of the... https://www.jove.com/v/40896 79 2026-04-13T21:37:37+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53479.jpg Fecal Glucocorticoid Analysis: Non-invasive Adrenal Monitoring in Equids Adrenal activity can be assessed in the equine species by analysis of feces for corticosterone metabolites. The method offers a non-invasive option to assess long term patterns in both domestic and free ranging horses. This protocol describes the enzyme linked immunoassay involved and the associated biochemical validation. https://www.jove.com/v/53479 482 2016-04-25T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58530.jpg Isolation, Fixation, and Immunofluorescence Imaging of Mouse Adrenal Glands Here we present a method to isolate adrenal glands from mice, fix the tissues, section them, and perform immunofluorescence staining. https://www.jove.com/v/58530 517 2018-10-02T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59016.jpg Primary Culture of Rat Adrenocortical Cells and Assays of Steroidogenic Functions The hormone secreted by the adrenal cortex is vital for animals against stress and diseases. Here, we present a protocol to culture the primary rat adrenal cells. It could be a good in vitro platform for investigating the mechanisms of the reagent of interest in adrenal steroidogenesis and lipid biosynthesis. https://www.jove.com/v/59016 273 2019-03-12T19:30:00+00:00 JoVE no https://visualize.jove.com/1701544-the-bin-area-method-a-computationally-efficient-technique-for-analysis-of-ventricular-and-atrial-intracardiac-electrograms monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15273.jpg Electrocardiogram An electrocardiogram (ECG or EKG) is a critical diagnostic tool that records the electrical signals produced by the heart during each heartbeat. This recording is achieved through electrodes placed strategically on the arms, legs, and chest. The electrocardiograph amplifies these signals and produces 12 distinct tracings, offering a comprehensive understanding of the heart's electrical activity. Three major waveforms are present in a typical ECG recording: the P wave, the QRS complex, and the T... https://www.jove.com/v/15273 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17877.jpg Electrocardiogram Fundamentals Introduction An electrocardiogram (ECG) is a diagnostic tool for identifying cardiac conditions such as arrhythmias, conduction abnormalities, and myocardial ischemia. Definition An electrocardiogram (ECG) visualizes the heart's electrical activity by tracing the electrical movement associated with each heartbeat on a graph or monitor. As the heart beats, an electrical wave passes through it, correlating with the cardiac cycle events. Parts of an ECG An ECG utilizes electrodes on the skin to... https://www.jove.com/v/17877 88 JoVE no https://cloudfront.jove.com/files/ftp_upload/18437/18437_article_thumb_18437.jpg ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias Arrhythmia is a condition characterized by an irregular heart rhythm, with ECG changes that differ based on its origin and nature. The types of arrhythmias discussed below include atrial, junctional, and ventricular arrhythmias.Atrial ArrhythmiasPremature Atrial Complexes (PACs): PACs are early atrial beats caused by stress, caffeine, alcohol, electrolyte imbalances, hypoxia, hyperthyroidism, or certain medications (e.g., bronchodilators and decongestants). The ECG shows early P waves with an... https://www.jove.com/v/18437 85 2025-06-19T16:15:27+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57234.jpg Ablation of Ischemic Ventricular Tachycardia Using a Multipolar Catheter and 3-dimensional Mapping System for High-density Electro-anatomical Reconstruction With the following protocol, we provide an approach to Ventricular Tachycardia (VT) ablation using high density mapping with a multipolar catheter and 3D mapping system enhancing the success of the procedure. https://www.jove.com/v/57234 417 2019-01-31T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63598.jpg Estimating Bilateral Atrial Function by Cardiovascular Magnetic Resonance Feature Tracking in Patients with Paroxysmal Atrial Fibrillation The atrial function is associated with the strain and strain rate. The cardiac magnetic resonance feature tracking (CMR-FT) technique was used in this study to quantify left and right atrial global and segmental longitudinal strain and strain rate in individuals with paroxysmal atrial fibrillation. https://www.jove.com/v/63598 490 2022-07-20T19:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67958.jpg Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System This study introduces a novel approach for real-time cardiac mapping using a noninvasive, imageless electrocardiographic imaging system. This system enables the acquisition of electrophysiological cardiac maps without requiring pre-procedural computed tomography or magnetic resonance imaging scans, enabling efficient guidance for cardiac procedures such as ablation and cardiac resynchronization therapy implants. https://www.jove.com/v/67958 617 2025-04-11T21:20:00+00:00 JoVE no https://visualize.jove.com/1706841-the-implantable-cardioverter-defibrillator-clinical-results monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3750.jpg A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation Dual-chamber implantable cardioverter-defibrillators (ICDs) may improve detection of atrial fibrillation as well as differentiation of tachycardias. However, this advantage is undermined by complications associated with the second electrode, which is required in conventional dual chamber devices. Therefore, BIOTRONIK has developed a new electrode called the LinoxSMART S DX that, when used in conjunction with the Lumax DX ICD, offers dual-chamber detection without the risks associated with the... https://www.jove.com/v/3750 1000 2012-02-28T22:00:00+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17930/17930_article_thumb_17930.jpg Acute Coronary Syndrome III: Diagnostic Studies Diagnosing acute coronary syndrome or ACS begins with a thorough patient history. Notable symptoms include central, crushing chest pain radiating to the left arm, neck, jaw, or back, along with shortness of breath, sweating (diaphoresis), nausea, vomiting, dizziness, and palpitations.It is crucial to note any history of cardiac illnesses and assess risk factors, including age, gender, smoking, hypertension, diabetes, hyperlipidemia, and a sedentary lifestyle.During physical examination, vital... https://www.jove.com/v/17930 90 2025-06-19T15:08:40+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17948/17948_article_thumb_17948.jpg Cardiopulmonary Resuscitation III: AED Use Introduction to AEDAn Automated External Defibrillator (AED) is a portable medical device that analyzes the heart's rhythm and, if necessary, delivers an electrical shock to help the heart re-establish an effective rhythm during sudden cardiac arrest (SCA). SCA occurs when the heart suddenly and unexpectedly stops beating, leading to a loss of blood flow to the brain and other vital organs. In such emergencies, time is of the essence, and using an AED, combined with Cardiopulmonary... https://www.jove.com/v/17948 83 2025-06-19T16:38:36+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17953/17953_article_thumb_17953.jpg Heart Failure III: Clinical Manifestations Heart failure (HF) manifests primarily as dyspnea, fatigue, and fluid retention, resulting in peripheral and pulmonary edema. Symptoms may vary depending on which ventricle is more affected, left or right.Left-Sided Heart FailureAlso known as left ventricular failure, this condition results from the left ventricle's inability to fill or eject sufficient blood into the systemic circulation. It leads to pulmonary congestion, which occurs when the left ventricle fails to eject blood effectively... https://www.jove.com/v/17953 86 2025-06-19T16:40:22+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17956/17956_article_thumb_17956.jpg Heart Failure VI: Adjunct Therapies Additional therapies for treating patients with heart failure (HF) may include procedural interventions, supplemental oxygen, the management of sleep disorders, and nutritional therapy.Procedural InterventionsImplantable Cardioverter-Defibrillator: For patients at risk of life-threatening arrhythmias due to severe left ventricular dysfunction, an Implantable Cardioverter-Defibrillator (ICD) can detect and terminate these arrhythmias, preventing sudden cardiac death and improving survival rates. https://www.jove.com/v/17956 82 2025-06-19T16:41:14+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17959/17959_article_thumb_17959.jpg Cardiomyopathy II: Dilated Cardiomyopathy Dilated cardiomyopathy, or DCM, is a progressive myocardial disorder characterized by ventricular chamber dilation and contractile dysfunction.EtiologyVarious factors can cause DCM, including hypertension and heavy alcohol intake, which contribute to the weakening and enlargement of the heart muscle. Viral infections, such as Coxsackievirus B, adenoviruses, and influenza, can lead to DCM by causing inflammation and damage to heart tissue. Certain chemotherapeutic agents, including daunorubicin,... https://www.jove.com/v/17959 90 2025-06-19T16:42:08+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17962/17962_article_thumb_17962.jpg Cardiomyopathy V: Interprofessional Care Managing cardiomyopathy involves addressing underlying or precipitating causes, treating heart failure with medications, and implementing dietary changes and a balanced exercise and rest regimen.Lifestyle ModificationsCardiomyopathy patients should adopt a low-sodium diet to reduce fluid retention and manage heart failure. A personalized exercise and rest plan helps maintain physical fitness without overstraining the heart. Avoiding alcohol and tobacco is essential to prevent further damage to... https://www.jove.com/v/17962 89 2025-06-19T16:42:59+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51569.jpg Implantation of Total Artificial Heart in Congenital Heart Disease This is a case report of a patient with congenitally corrected transposition of the great arteries (CCTGA) who received a total artificial heart (TAH) as a bridge to heart transplant. The TAH was successfully implanted with modifications to accommodate the patient's congenitally malformed heart. https://www.jove.com/v/51569 447 2014-07-18T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67958.jpg Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System This study introduces a novel approach for real-time cardiac mapping using a noninvasive, imageless electrocardiographic imaging system. This system enables the acquisition of electrophysiological cardiac maps without requiring pre-procedural computed tomography or magnetic resonance imaging scans, enabling efficient guidance for cardiac procedures such as ablation and cardiac resynchronization therapy implants. https://www.jove.com/v/67958 617 2025-04-11T21:20:00+00:00 JoVE no https://visualize.jove.com/1749201-the-spontaneous-course-of-small-abdominal-aortic-aneurysms-aneurysmal-growth-rates-and-life-expectancy monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15308.jpg The Aorta The aorta is the largest artery in the human body. It originates from the left ventricle of the heart and extends down to the abdomen, where it splits into two smaller arteries. Structurally, it can be divided into four main parts: the ascending aorta, the aortic arch, the thoracic aorta, and the abdominal aorta. The average diameter of the aorta is approximately 2-3 cm, but the size can vary depending on the section of the aorta and the individual's age, sex, and body size. The aorta is... https://www.jove.com/v/15308 74 JoVE no https://cloudfront.jove.com/files/ftp_upload/17903/17903_article_thumb_17903.jpg Aortic Regurgitation I: Introduction IntroductionAortic regurgitation is characterized by the backward flow of blood from the aorta into the left ventricle during diastole and arises from the improper closure of the aortic valve. This condition results in left ventricular volume overload and can stem from both acute and chronic etiologies, each contributing uniquely to the disease's progression and symptomatology.Acute and Chronic CausesAcute aortic regurgitation often results from events that suddenly impair the integrity of the... https://www.jove.com/v/17903 75 2025-06-19T16:20:10+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17979/17979_article_thumb_17979.jpg Aneurysm I: Introduction An aortic aneurysm is a localized outpouching or dilation at a weak point in the artery wall. It may involve different parts of the aorta, such as the abdominal aorta, aortic arch, or thoracic aorta.Etiological factorsSeveral disorders are associated with aortic aneurysms.Congenital causes, such as primary connective tissue disorders like Marfan syndrome, impact the integrity and strength of connective tissues, notably affecting the aorta. Marfan syndrome is a genetic disorder that specifically... https://www.jove.com/v/17979 90 2025-06-19T16:19:01+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17980/17980_article_thumb_17980.jpg Aneurysm II: Clinical Manifestations and Diagnostic Studies Thoracic, aortic arch and abdominal aneurysms are significant vascular conditions that can present with various clinical manifestations and lead to serious complications. Understanding these manifestations and the appropriate diagnostic studies is essential for effective management and treatment.Thoracic Aortic AneurysmsThoracic aortic aneurysms often remain asymptomatic until they reach a size that impinges on adjacent structures. They typically cause deep, diffuse chest pain that radiates to... https://www.jove.com/v/17980 81 2025-06-19T16:19:14+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17981/17981_article_thumb_17981.jpg Aneurysm III: Interprofessional Care Aneurysm management involves either conservative medical therapy or surgical intervention, depending on the size and symptoms of the aneurysm. Conservative management is generally reserved for smaller, asymptomatic aneurysms, while larger or symptomatic aneurysms often necessitate surgical repair.Conservative Medical TherapyFor small, asymptomatic aneurysms, particularly abdominal aortic aneurysms (AAA) less than 5.5 centimeters in diameter, conservative medical therapy is recommended. This... https://www.jove.com/v/17981 86 2025-06-19T16:19:25+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17982/17982_article_thumb_17982.jpg Aneurysm IV: Nursing Management Vigilant monitoring for aneurysm rupture is essential for patients undergoing aortic surgery.Preoperative Nursing ManagementContinuously monitor the patient for manifestations of aneurysm rupture, such as pallor, weakness, tachycardia, hypotension, abdominal, back, groin, or periumbilical pain, changes in consciousness, and a pulsating abdominal mass. Regularly assess the patient's peripheral pulses.Instruct the patient to consume a clear liquid diet the day before surgery and administer... https://www.jove.com/v/17982 82 2025-06-19T16:19:35+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55763.jpg Creation of a Rodent Model of Abdominal Aortic Aneurysm by Blocking Adventitial Vasa Vasorum Perfusion Polyurethane catheter insertion into the aortic lumen and suture ligation of the aorta induce chronic hypoxia due to hypoperfusion of the adventitial vasa vasorum. This article describes a novel animal model of abdominal aortic aneurysm (AAA) with characteristics similar to those of AAA in humans. https://www.jove.com/v/55763 517 2017-11-08T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57984.jpg Manufacturing Abdominal Aorta Hydrogel Tissue-Mimicking Phantoms for Ultrasound Elastography Validation Here we describe a method to manufacture aneurysmal, aortic tissue-mimicking phantoms for the use in testing ultrasound elastography. The combined use of computer-aided design (CAD) and 3-dimensional (3D) printing techniques produce aortic phantoms with predictable, complex geometries to validate the elastographic imaging algorithms with controlled experiments. https://www.jove.com/v/57984 572 2018-09-19T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60515.jpg Measurement of Pulse Propagation Velocity, Distensibility and Strain in an Abdominal Aortic Aneurysm Mouse Model This manuscript describes a detailed protocol for using high frequency ultrasound imaging to measure luminal diameter, pulse propagation velocity, distensibility and radial strain on a mouse model of abdominal aortic aneurysm. https://www.jove.com/v/60515 572 2020-02-23T21:00:00+00:00 JoVE no https://visualize.jove.com/1772567-alpha-oligonucleotides-a-unique-class-of-modified-chimeric-nucleic-acids monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10684.jpg Nucleic acids Nucleic acids are the most important macromolecules for the continuity of life. They carry the cell's genetic blueprint and carry instructions for its functioning. DNA and RNA The two main types of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA is the genetic material in all living organisms, ranging from single-celled bacteria to multicellular mammals. It is in the nucleus of eukaryotes and in the organelles, chloroplasts, and mitochondria. In prokaryotes, the... https://www.jove.com/v/10684 163 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11473.jpg Nucleic Acids Nucleic acids are the most important macromolecules for the continuity of life. They carry the cell's genetic blueprint and carry instructions for its functioning. DNA and RNA The two main types of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA is the genetic material in all living organisms, ranging from single-celled bacteria to multicellular mammals. It is in the nucleus of eukaryotes and in the organelles, chloroplasts, and mitochondria. In prokaryotes, the... https://www.jove.com/v/11473 163 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11474.jpg DNA Base Pairing Erwin Chargaff’s rules on DNA equivalence paved the way for the discovery of base pairing in DNA. Chargaff’s rules state that in a double-stranded DNA molecule, the amount of adenine (A) is equal to the amount of thymine (T); the amount of guanine (G) is equal to the amount of cytosine (C); and the sum of purines, A and G, is equal to the sum of pyrimidines, C and T (i.e., A+G = C+T). Later work by Watson and Crick revealed that in double-stranded DNA, A always forms two hydrogen bonds... https://www.jove.com/v/11474 147 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13908.jpg Nucleic Acids and Nucleotides Nucleic acids are the most important macromolecules for the continuity of life. They carry the cell's genetic blueprint and have instructions for its functioning. The two main types of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Deoxyribonucleic Acid (DNA) DNA is the genetic material in all living organisms, ranging from single-celled bacteria to multicellular mammals. It is in the nucleus of eukaryotes and the organelles such as chloroplasts and mitochondria. In... https://www.jove.com/v/13908 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14371.jpg Nucleic Acid Structure The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group on the ribose's second carbon and a hydrogen on the deoxyribose's second carbon. The phosphate residue attaches to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms a 5′ to 3′ phosphodiester linkage. DNA Structure DNA has a double-helix structure. The... https://www.jove.com/v/14371 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14446.jpg Direct-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship Cholinergic agonists or cholinomimetics mimic the action of acetylcholine to stimulate the parasympathetic nervous system. They are categorized into direct-acting and indirect-acting agents. The direct-acting cholinergic drugs induce the parasympathetic response by directly binding to the muscarinic or nicotine receptors. In comparison, the indirect-acting cholinergic drugs prevent acetylcholine hydrolysis, indirectly contributing to the extended parasympathetic response. The direct-acting... https://www.jove.com/v/14446 82 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56221.jpg Sequence-specific and Selective Recognition of Double-stranded RNAs over Single-stranded RNAs by Chemically Modified Peptide Nucleic Acids We report the protocols for the synthesis and purification of Peptide Nucleic Acid (PNA) oligomers incorporating modified residues. The biochemical and biophysical methods for the characterization of the recognition of RNA duplexes by the modified PNAs are described. https://www.jove.com/v/56221 544 2017-09-21T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58066.jpg Genetic Encoding of a Non-Canonical Amino Acid for the Generation of Antibody-Drug Conjugates Through a Fast Bioorthogonal Reaction Incorporating a cyclopropene derivative of lysine into antibodies allows the site-specific, rapid and efficient linkage of tetrazine-bearing molecules to generate antibody-drug conjugates. https://www.jove.com/v/58066 662 2018-09-14T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66930.jpg Using Modified Synthetic Oligonucleotides to Assay Nucleic Acid-Metabolizing Enzymes Here, a protocol for assaying nucleic acid metabolizing enzymes is presented, using examples of ligase, nuclease, and polymerase enzymes. The assay utilizes fluorescently labeled and unlabeled oligonucleotides that can be combined to form duplexes mimicking RNA and/or DNA damages or pathway intermediates, allowing for the characterization of enzyme behavior. https://www.jove.com/v/66930 333 2024-07-05T21:30:00+00:00 JoVE no https://visualize.jove.com/1799223-could-angiotensin-i-be-produced-from-a-renin-substrate-by-the-hiv-1-protease monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15023.jpg Antihypertensive Drugs: Angiotensin-Converting Enzyme Inhibitors Angiotensin-converting enzyme (ACE), a vital component of the renin-angiotensin-aldosterone system, is abundant in lung endothelial cells. ACE converts the inactive decapeptide, angiotensin I, into the active octapeptide, angiotensin II. This potent vasoconstrictor narrows blood vessels, increasing resistance to blood flow and elevating blood pressure. Angiotensin II also stimulates aldosterone production, encouraging kidney cells to reabsorb more sodium and water from urine, thereby increasing... https://www.jove.com/v/15023 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15024.jpg Antihypertensive Drugs: Angiotensin II Receptor Blockers In the renin-angiotensin-aldosterone system, a hormone called angiotensin II plays a crucial role. It binds to the AT1 receptors in vascular smooth muscles coupled with Gq proteins. The activation of these receptors activates an enzyme called phospholipase C, which releases two molecules: inositol trisphosphate and diacylglycerol. These molecules cause a chain reaction that leads to the phosphorylation of myosin light chains and promotes interaction between actin and myosin, leading to smooth... https://www.jove.com/v/15024 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15025.jpg Antihypertensive Drugs: Direct Renin Inhibitors The renin-angiotensin-aldosterone system (RAAS) is an intricate physiological pathway involving numerous enzymes and hormones, including renin, angiotensin-converting enzyme (ACE), angiotensin I and II, and aldosterone. Imbalances within this system increase the production of angiotensin II and aldosterone. Increased angiotensin II levels promote vasoconstriction and blood pressure elevation. Concurrently, higher aldosterone levels stimulate sodium and water reabsorption in the kidneys,... https://www.jove.com/v/15025 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15037.jpg Heart Failure Drugs: Inhibitors of Renin-Angiotensin System The activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) contributes to cardiac remodeling, and inhibiting the RAAS is a pharmacological target in heart failure management. As a result, neurohumoral modulation is a crucial treatment principle for managing heart failure. This approach involves using medications like ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), β-blockers, mineralocorticoid receptor antagonists (MRAs), and neutral... https://www.jove.com/v/15037 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/41743/41743_article_thumb_41743.jpg Inhibitors of Virion Maturation and Assembly As part of their replication cycle, certain viruses synthesize long precursor proteins called polyproteins within infected host cells. In human immunodeficiency virus (HIV), two major polyproteins are produced: Gag and Gag-Pol. The Gag polyprotein supplies the structural components of the virus, while Gag-Pol includes essential viral enzymes such as reverse transcriptase, integrase, and protease. After synthesis, these polyproteins move to the host cell membrane, where they assemble into an... https://www.jove.com/v/41743 79 2026-05-20T21:38:19+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53866.jpg Receptor Autoradiography Protocol for the Localized Visualization of Angiotensin II Receptors Here we present a protocol to describe the localization of angiotensin II Type 1 receptors in the rat brain by quantitative, densitometric, in vitro receptor autoradiography using an iodine-125 labeled analog of angiotensin II. https://www.jove.com/v/53866 723 2016-06-07T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58824.jpg Use of Recombinant Fusion Proteins in a Fluorescent Protease Assay Platform and Their In-gel Renaturation Here, we present the detailed procedure of a recently developed protease assay platform utilizing N-terminal hexahistidine/maltose-binding protein and fluorescent protein-fused recombinant substrates attached to the surface of nickel-nitrilotriacetic acid magnetic agarose beads. A subsequent in-gel analysis of the assay samples separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis is also presented. https://www.jove.com/v/58824 1163 2019-01-16T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60511.jpg Detection of Human Immunodeficiency Virus Type 1 (HIV-1) Antisense Protein (ASP) RNA Transcripts in Patients by Strand-Specific RT-PCR RNA hairpins and loops can function as primers for reverse transcription (RT) in absence of sequence-specific primers, interfering with the study of overlapping antisense transcripts. We have developed a technique able to identify strand-specific RNA, and we have used it to study HIV-1 antisense protein ASP. https://www.jove.com/v/60511 481 2019-11-27T22:00:00+00:00 JoVE no https://visualize.jove.com/1802345-suppression-of-amygdala-kindling-with-massed-stimulation-effect-of-noradrenaline-antagonists monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3446.jpg Habituation and Prepulse Inhibition of Acoustic Startle in Rodents Habituation and prepulse inhibition of startle are operational measures of sensory gating. Sensory gating is disrupted in schizophrenia, and some other mental disorders and neurodegenerative diseases. We here describe a standard protocol to assess short-term and long-term habituation as well as prepulse inhibition of acoustic startle responses in rats and mice. https://www.jove.com/v/3446 518 2011-09-01T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14439.jpg Desensitization and Tachyphylaxis Tachyphylaxis is described as a rapid decrease in response to a drug after repeated or continuous administration of the same drug dose. It is a phenomenon where the body becomes less responsive to a particular substance or intervention over time, requiring higher doses or stronger interventions to achieve the same effect. It results from adaptive changes in the body's receptors, signaling pathways, or physiological processes that occur in response to prolonged exposure to a stimulus. Several... https://www.jove.com/v/14439 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14464.jpg Adrenergic Neurons: Neurotransmission Postganglionic sympathetic fibers (except those supplying the sweat glands) releasing noradrenaline or norepinephrine are called noradrenergic or adrenergic neurons. Noradrenaline, dopamine, adrenaline, or epinephrine are collectively called "catecholamines" as they contain a catechol moiety and an amine side chain. The five stages of neurotransmitter release involve their synthesis, storage, release, reuptake and metabolism. Synthesis: Catecholamine synthesis requires tyrosine, which is taken... https://www.jove.com/v/14464 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14469.jpg Adrenergic Agonists: Indirect-Acting Agents Indirect-acting adrenergic agonists potentiate the effects of endogenous catecholamines through different mechanisms without directly binding to adrenoceptors. One mechanism involves depleting stored catecholamines by displacing them from synaptic vesicles. These agents, known as "displacers," are transported into vesicles at the expense of noradrenaline. Examples include amphetamine and tyramine, which lack a catechol moiety, resulting in prolonged action, improved oral bioavailability, and... https://www.jove.com/v/14469 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14473.jpg Adrenergic Agonists: Therapeutic Uses Adrenergic agonists have diverse therapeutic uses across various medical conditions and emergencies. Emergency and Intensive Care Unit (ICU) applications: Pressor agents increase blood pressure, heart rate, and contractility in shock and organ failure situations. Dopamine can induce vasodilation and stimulate adrenoceptors. Endogenous catecholamines are effective in treating cardiogenic shock. α2-agonists like clonidine can reverse anesthesia-induced hypertension. Allergies and anaphylaxis:... https://www.jove.com/v/14473 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14479.jpg Drugs Affecting Neurotransmitter Release or Uptake Certain drugs can affect how neurotransmitters called catecholamines, are released or taken back up in the adrenergic neuron. They can have different effects on the body's sympathetic transmission. Reserpine, a natural compound found in the Rauwolfia shrub, blocks a transporter called vesicular monoamine transporter (VMAT), which leads to a buildup of catecholamines in the cell and reduces sympathetic transmission. Another drug called guanethidine works in multiple ways, including blocking... https://www.jove.com/v/14479 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18185.jpg Role of Amygdala in Memory The amygdala is a small, almond-shaped structure responsible for processing and storing memories, particularly those linked to emotions like fear and stress. It plays an essential role in the brain's response to emotionally significant events and often enhances memory formation by triggering stress hormone release. The amygdala is vital for encoding and retrieving memories associated with fear or stress, a process that is adaptive by helping organisms avoid dangerous situations. One of the... https://www.jove.com/v/18185 76 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52151.jpg Disrupting Reconsolidation of Fear Memory in Humans by a Noradrenergic β-Blocker Disrupting reconsolidation is a promising approach to dampen the behavioral expression of fear memory in patients with anxiety disorders or posttraumatic stress disorder. In a series of human fear conditioning studies we showed that disrupting reconsolidation by the noradrenergic β-blocker propranolol is very effective in erasing conditioned fear responding. https://www.jove.com/v/52151 512 2014-12-18T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53032.jpg Vagus Nerve Stimulation as a Tool to Induce Plasticity in Pathways Relevant for Extinction Learning Vagus nerve stimulation (VNS) has emerged as a tool to induce targeted synaptic plasticity in the forebrain to modify a range of behaviors. This protocol describes how to implement VNS to facilitate the consolidation of fear extinction memory. https://www.jove.com/v/53032 662 2015-08-21T21:00:00+00:00 JoVE no https://visualize.jove.com/1806129-a-stochastic-model-for-the-development-of-an-aids-epidemic-in-a-heterosexual-population monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2312.jpg Comprehensive & Cost Effective Laboratory Monitoring of HIV/AIDS: an African Role Model Anti-retroviral therapy to treat HIV/AIDS is monitored in South Africa on a large scale. Flow cytometry is combined for haematology (CD45), immunology (CD4) and viral-load linked CD38 assay. Recorded at NHLS-SA laboratories, Johannesburg, these modern methods are cost-efficient with heightened local internal quality control, serving as role-models for resource-limited diagnostics. https://www.jove.com/v/2312 1436 2010-11-01T00:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10825.jpg Retrovirus Life Cycles Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the retrovirus to... https://www.jove.com/v/10825 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16319.jpg Sexually Transmitted Infections Sexually transmitted infections (STIs) are diseases transmitted primarily through unsafe sexual interactions. Bacteria, viruses, or parasites cause them and can result in severe health complications if untreated.ChlamydiaThe bacterium Chlamydia trachomatis is responsible for the disease Chlamydia, the most common STI in the United States. This peculiar pathogen requires human cells to reproduce, residing intracellularly. The initial infection often goes unnoticed because it typically does not... https://www.jove.com/v/16319 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/17240/17240_article_thumb_17240.jpg Pharmacodynamic Models: Additive and Proportional Drug Effect Model Drug response models describe how pharmacological agents interact with biological systems to produce measurable effects. Baseline responses are inherent physiological activities without a drug significantly influencing the observed pharmacological outcomes. Depending on the drug response model employed, these baseline responses may combine with the drug's effect in either an additive or proportional manner.Additive Drug Response ModelIn the additive model, the drug effect is independent of the... https://www.jove.com/v/17240 69 2026-02-12T19:17:24+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17610.jpg Statistical Methods for Analyzing Epidemiological Data Epidemiological data primarily involves information on specific populations' occurrence, distribution, and determinants of health and diseases. This data is crucial for understanding disease patterns and impacts, aiding public health decision-making and disease prevention strategies. The analysis of epidemiological data employs various statistical methods to interpret health-related data effectively. Here are some commonly used methods: Descriptive Statistics: These provide basic summaries... https://www.jove.com/v/17610 85 JoVE no https://cloudfront.jove.com/files/ftp_upload/40598/40598_article_thumb_40598_TN.jpg Modeling with Differential Equations Population dynamics can be described mathematically by considering the population size P(t) as a function of time. The rate of change of the population is then represented by the derivative of P(t). A simple assumption is that the rate of growth is proportional to the size of the population itself. This leads to an exponential growth model, where the population increases rapidly without bound. While this is a useful first approximation, it does not reflect realistic long-term... https://www.jove.com/v/40598 85 2026-01-12T20:24:36+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40856/40856_article_thumb_40856.jpg Amebiasis Entamoeba histolytica, a protozoan parasite, is responsible for intestinal and extraintestinal amebiasis. Though a significant proportion of infections remain asymptomatic, approximately 50 million individuals annually are estimated to present with clinical disease, resulting in up to 100,000 deaths globally. The disease burden is disproportionately high in regions with lower socioeconomic status, such as parts of India, Africa, Mexico, and Latin America.Etiology and TransmissionThe infective... https://www.jove.com/v/40856 88 2026-05-20T21:29:57+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58255.jpg Humanized NOD/SCID/IL2rγ null (hu-NSG) Mouse Model for HIV Replication and Latency Studies This protocol provides a method to establish humanized mice (hu-NSG) via intrahepatic injection of human hematopoietic stem cells into radiation-conditioned neonatal NSG mice. The hu-NSG mouse is susceptible to HIV infection and combinatorial antiretroviral therapy (cART) and serves as a suitable pathophysiological model for HIV replication and latency investigations. https://www.jove.com/v/58255 430 2019-01-07T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62137.jpg A Rat Model of EcoHIV Brain Infection Here, we present a protocol to establish a new rat model of active HIV infection using chimeric HIV (EcoHIV), which is critical for enhancing our understanding of HIV-1 viral reservoirs in the brain and offering a system to study HIV-associated neurocognitive disorders and associated comorbidities (i.e., drug abuse). https://www.jove.com/v/62137 528 2021-01-21T22:30:00+00:00 JoVE no https://visualize.jove.com/1822443-the-construction-of-different-types-of-aggregates-and-chimaeric-aggregates-from-individual-blastomeres-of-mouse-8-cell-embryos monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2677.jpg Chromatin Immunoprecipitation Assay for Tissue-specific Genes using Early-stage Mouse Embryos We demonstrate a chromatin immunoprecipitation (ChIP) method to identify factor interactions at tissue-specific genes during or after the onset of tissue-specific gene expression in mouse embryonic tissue. This protocol should be widely applicable for the study of tissue-specific gene activation as it occurs during normal embryonic development. https://www.jove.com/v/2677 662 2011-04-29T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/4458.jpg Blastomere Explants to Test for Cell Fate Commitment During Embryonic Development The fate of an individual embryonic cell can be influenced by inherited molecules and/or by signals from neighboring cells. Utilizing fate maps of the cleavage stage Xenopus embryo, single blastomeres can be identified for culture in isolation to assess the contributions of inherited molecules versus cell-cell interactions. https://www.jove.com/v/4458 848 2013-01-26T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10908.jpg Cleavage and Blastulation After a large-single-celled zygote is produced via fertilization, the process of cleavage occurs while zygotes travel through the uterine tube. Cleavage is a mitotic cell division that does not result in growth. With each round of successive cell division, daughter cells get increasingly smaller. Zygotic Genome Activation At the beginning of embryogenesis, maternal mRNAs control development. However, by the eight-cell stage of cleavage, embryonic genes become activated in a process called... https://www.jove.com/v/10908 93 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53252.jpg Generation of Aggregates of Mouse Embryonic Stem Cells that Show Symmetry Breaking, Polarization and Emergent Collective Behaviour In Vitro We have developed a protocol to generate aggregates of mouse embryonic stem cells that display self-organization, symmetry breaking and elongation paralleling axial development. This technique allows the study of axial developmental processes and the generation of cell types that are otherwise difficult to perform in monolayer culture. https://www.jove.com/v/53252 697 2015-11-24T23:00:00+00:00 JoVE no https://visualize.jove.com/1974726-23-dideoxyinosine-in-patients-with-aids-or-aids-related-complex monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10825.jpg Retrovirus Life Cycles Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the retrovirus to... https://www.jove.com/v/10825 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11572.jpg Retroviruses Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’... https://www.jove.com/v/11572 153 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15356.jpg Immunodeficiency Diseases Immunodeficiency disorders are conditions in which the immune system's ability to fight infectious disease and cancer is compromised or entirely absent. The immune system comprises a complex network of cells, tissues, and organs that work together to protect the body from potentially harmful invaders. When this system is deficient or not functioning properly, it leaves the body susceptible to infections, diseases, or other complications. There are three main causes of immunodeficiency disorders... https://www.jove.com/v/15356 85 JoVE no https://cloudfront.jove.com/files/ftp_upload/40851/40851_article_thumb_40851.jpg Cryptococcal Meningitis Cryptococcal meningitis is a life-threatening opportunistic infection predominantly associated with HIV/AIDS, accounting for over 100,000 deaths annually worldwide. However, it also affects individuals with other forms of immunosuppression, including those undergoing immunosuppressive therapy, organ transplant recipients, patients with innate immunodeficiencies, and individuals with hematological disorders. The infection is caused mainly by Cryptococcus neoformans and Cryptococcus gattii,... https://www.jove.com/v/40851 87 2026-05-20T21:22:09+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40862/40862_article_thumb_40862.jpg Inhibitors of Viral Protein Synthesis Protein synthesis is indispensable for viral replication, as viruses lack the cellular machinery required for this process and must hijack the host's translational apparatus. In response, host cells deploy a critical innate immune defense involving interferons, specialized cytokines that play a central role in inhibiting viral propagation.Upon viral detection, infected cells release interferons that bind to receptors on adjacent uninfected cells, activating the JAK-STAT signaling pathway and... https://www.jove.com/v/40862 90 2026-03-12T20:36:03+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40864/40864_article_thumb_40864.jpg Antiviral Nucleoside Inhibitors Antiviral Nucleoside InhibitorsAntiviral nucleoside inhibitors are structural analogs of natural nucleosides that interfere with viral DNA or RNA synthesis. These compounds selectively target viral polymerases due to their resemblance to host nucleosides, thereby disrupting viral genome replication.Mechanism of Acyclovir ActionAcyclovir is a guanosine analog with a three-carbon acyclic side chain. It selectively targets herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2),... https://www.jove.com/v/40864 82 2026-05-20T21:37:01+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51400.jpg Rapid Screening of HIV Reverse Transcriptase and Integrase Inhibitors Here we describe cellular cytotoxicity and single round infectivity assays that allow for the rapid and accurate screening of compounds to determine their cellular cytotoxicity (CC50) and IC50 values against WT and drug resistant HIV-1. https://www.jove.com/v/51400 346 2014-04-10T04:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63696.jpg Oral Combinational Antiretroviral Treatment in HIV-1 Infected Humanized Mice This protocol describes a novel method to deliver oral combinational antiretroviral drugs that successfully suppress HIV-1 RNA replication in humanized mice. https://www.jove.com/v/63696 367 2022-10-06T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67457.jpg Quantitative Structure-Activity Relationship, Activity Prediction, and Molecular Dynamics of Non-nucleotide Reverse Transcriptase Inhibitors This study used in-silico strategies to identify Enumerated Etravirine as a promising therapeutic agent for HIV. Our findings on molecular interactions and dynamics support the rational design of novel NNRTIs as possible HIV treatment alternatives. https://www.jove.com/v/67457 629 2025-05-09T19:40:00+00:00 JoVE no https://visualize.jove.com/2148555-norepinephrine-evoked-calcium-transients-in-cultured-cerebral-type-1-astroglia monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1142.jpg Measuring Near Plasma Membrane and Global Intracellular Calcium Dynamics in Astrocytes We describe how to measure near membrane and global intracellular calcium dynamics in cultured astrocytes using total internal reflection and epifluorescence microscopy. https://www.jove.com/v/1142 768 2009-04-27T06:27:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/4418.jpg Dual Electrophysiological Recordings of Synaptically-evoked Astroglial and Neuronal Responses in Acute Hippocampal Slices The preparation of acute brain slices from isolated hippocampi, as well as the simultaneous electrophysiological recordings of astrocytes and neurons in stratum radiatum during stimulation of schaffer collaterals is described. The pharmacological isolation of astroglial potassium and glutamate transporter currents is demonstrated. https://www.jove.com/v/4418 998 2012-11-26T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51458.jpg Inducing Plasticity of Astrocytic Receptors by Manipulation of Neuronal Firing Rates Here we describe an adaptation of protocols used to induce homeostatic plasticity in neurons for the study of plasticity of astrocytic G protein-coupled receptors. Recently used to examine changes in astrocytic group I mGluRs in juvenile mice, the method can be applied to measure scaling of various astrocytic GPCRs, in tissue from adult mice in situ and in vivo, and to gain a better appreciation of the sensitivity of astrocytic receptors to changes in neuronal activity. https://www.jove.com/v/51458 767 2014-03-21T02:30:00+00:00 JoVE no https://visualize.jove.com/2163294-expression-of-nak-atpase-alpha-and-beta-subunit-genes-during-preimplantation-development-of-the-mouse monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2797.jpg Whole Mount in Situ Hybridization of E8.5 to E11.5 Mouse Embryos This whole mount in situ hybridization protocol discusses critical steps that ensure reproducible high quality results for gene expression studies in E8.5-E11.5 day old mouse embryos. https://www.jove.com/v/2797 834 2011-10-10T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53654.jpg Quantitative Analysis of Protein Expression to Study Lineage Specification in Mouse Preimplantation Embryos This protocol presents a method to perform quantitative, single-cell in situ analysis of protein expression to study lineage specification in mouse preimplantation embryos. The procedures necessary for collection of blastocysts, whole-mount immunofluorescent detection of proteins, imaging of samples on a confocal microscope, and nuclear segmentation and image analysis are described. https://www.jove.com/v/53654 685 2016-02-22T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53696.jpg Loss- and Gain-of-function Approach to Investigate Early Cell Fate Determinants in Preimplantation Mouse Embryos The goal of this protocol is to describe a loss- and gain-of function method that is applicable to identify neogenin as a stage-specific receptor that leads to trophectoderm and inner cell mass differentiation in preimplantation mouse embryos. https://www.jove.com/v/53696 523 2016-06-06T20:00:00+00:00 JoVE no https://visualize.jove.com/2169592-anion-channels-activated-by-adrenaline-in-cardiac-myocytes monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13323.jpg G-Protein Gated Ion Channels GPCRs are primarily responsible for our sense of smell, taste, and vision. The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response. Sensory organs,... https://www.jove.com/v/13323 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14467.jpg Adrenergic Receptors: β Subtype β-adrenoceptors have varied sensitivities towards adrenaline, noradrenaline, and isoprenaline. The order of agonist potency is as follows: Isoprenaline > Adrenaline > Noradrenaline Neurotransmitter binding to these receptors causes activation of adenylyl cyclase resulting in increased concentrations of cAMP and modulation of calcium ion channels within the cell. They are further classified into β1, β2, and β3 subtypes. β1-adrenoceptors: β1-adrenoceptors have equal affinities for... https://www.jove.com/v/14467 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14951.jpg Sympathetic Signaling Sympathetic signaling, a vital part of the autonomic nervous system, plays a crucial role in mobilizing the body's resources in response to stress or emergencies. It involves the transmission of nerve impulses from sympathetic preganglionic fibers to postganglionic fibers. This results in the release of specific neurotransmitters and activation of adrenergic receptors. Sympathetic preganglionic fibers release the neurotransmitter acetylcholine (ACh) onto the ganglionic neurons in the... https://www.jove.com/v/14951 91 2025-08-12T19:30:45+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15022.jpg Antihypertensive Drugs: Action of Calcium Channel Blockers Calcium ions are essential to contract smooth muscle cells in blood vessels. They enter these cells through voltage-dependent calcium channels, specifically L-type calcium channels in the cell membrane. These L-type calcium channels are integral to the excitation-contraction coupling process in smooth muscle. When a stimulus is received by smooth muscle cells, their membrane depolarizes. This alteration in membrane potential instigates the opening of L-type calcium channels. As a result,... https://www.jove.com/v/15022 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15280.jpg Regulation of Heart Rates The regulation of heart rate is a complex process controlled by the autonomic nervous system (ANS), hormonal influences, and intrinsic cardiac mechanisms. The ANS has two main components: the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). The SNS increases heart rate through the release of norepinephrine and epinephrine, which act on beta-1 adrenergic receptors in the heart. This action increases the rate of depolarization in the sinoatrial (SA) node, the heart's... https://www.jove.com/v/15280 91 2025-05-15T16:18:44+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17864.jpg Cardiac Action Potential Cardiac action potentials are essential for proper heart function, enabling the rhythmic contractions needed for adequate blood circulation. Nodal cells and Purkinje fibers, specialized for electrical conduction, generate these action potentials. The cardiac action potential process involves a series of phases characterized by the movement of ions across the cardiac cell membranes, leading to the depolarization and repolarization of the cardiac myocytes. Ionic Basis of Cardiac Action Potentials<br... https://www.jove.com/v/17864 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50235.jpg Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca 2+ Transients and Membrane Currents We describe the isolation of human atrial myocytes which can be used for intracellular Ca2+ measurements in combination with electrophysiological patch-clamp studies. https://www.jove.com/v/50235 653 2013-07-03T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57617.jpg Impact of Intracardiac Neurons on Cardiac Electrophysiology and Arrhythmogenesis in an Ex Vivo Langendorff System Here, we present a protocol for the modulation of the intracardiac autonomic nervous system and the assessment of its influence on basic electrophysiology, arrhythmogenesis, and cAMP dynamics using an ex vivo Langendorff setup. https://www.jove.com/v/57617 400 2018-05-22T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59588.jpg Isolation of Atrial Myocytes from Adult Mice This protocol is used to isolate single atrial cardiomyocytes from the adult mouse heart using a chunk digestion approach. This approach is used to isolate right or left atrial myocytes that can be used to characterize atrial myocyte electrophysiology in patch-clamp studies. https://www.jove.com/v/59588 514 2019-07-25T21:00:00+00:00 JoVE no https://visualize.jove.com/2171048-administration-of-adrenocorticotropic-hormone-acth-enhances-fos-expression-in-the-rat-adrenal-cortex monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10879.jpg Hypothalamic-Pituitary Axis The response to stress—be it physical or psychological, acute or chronic—involves activation of the Hypothalamic-Pituitary-Adrenal (HPA) axis. The HPA axis is part of the neuroendocrine system because it involves both neuronal and hormonal communication. Its function is to regulate homeostatic systems—metabolic, cardiovascular, and immune—providing the necessary means to respond to a stressor. What Happens During Stress In response to stress, the neurons in the hypothalamus release... https://www.jove.com/v/10879 97 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14986.jpg Anatomy of the Adrenal Glands The adrenal or supra-renal glands, situated above the kidneys and aligned with the twelfth rib, are paired pyramid-shaped structures crucial for the body's stress response. During stress, these glands secrete hormones vital for adaptive physiological reactions. These glands possess a distinctive yellow tinge due to the stored cholesterol and fatty acids required for hormone synthesis. They are encased in a fibrous capsule and cushioned by fat. The adrenal gland comprises two distinct regions... https://www.jove.com/v/14986 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14987.jpg Hormones of the Adrenal Glands Adrenal hormones play a pivotal role in maintaining the body's electrolyte balance and orchestrating responses to stress, showcasing the intricate functions of the adrenal cortex and medulla. The adrenal cortex, a powerhouse of hormone synthesis, generates over two dozen corticosteroid hormones. The zona glomerulosa produces mineralocorticoids, exemplified by aldosterone, influencing the electrolyte composition of body fluids. The synthesis of glucocorticoids such as cortisol and corticosterone... https://www.jove.com/v/14987 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14988.jpg Adrenal Gland Disorders Adrenal gland disorders manifest when the production of adrenal hormones deviates from the norm, resulting in either excessive or insufficient concentrations. Adrenal insufficiency, characterized by insufficient cortisol and aldosterone production, leads to conditions like Addison's disease. This disorder, affecting the adrenal cortex, exhibits symptoms such as skin bronzing, dehydration, low blood pressure, fatigue, and weight loss. Congenital adrenal hyperplasia, a genetic ailment causing... https://www.jove.com/v/14988 87 JoVE no https://cloudfront.jove.com/files/ftp_upload/40895/40895_article_thumb_40895.jpg Cushing Syndrome I: Introduction Cushing syndrome refers to the collection of clinical manifestations that arise when tissues are exposed to excessive amounts of cortisol or cortisol-like medications over an extended period. Cortisol, a glucocorticoid produced by the adrenal cortex, regulates metabolism, immune responses, and the body’s adaptation to stress. When its concentration remains chronically elevated, these physiological pathways become dysregulated, resulting in the characteristic features of the syndrome.Exogenous... https://www.jove.com/v/40895 86 2026-04-13T21:37:50+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40896/40896_article_thumb_40896.jpg Cushing Syndrome II: Pathophysiology Cortisol production is normally governed by the hypothalamic–pituitary–adrenal (HPA) axis, which maintains hormonal balance through tightly regulated feedback mechanisms. Disruption of this regulatory system is central to the development of Cushing syndrome, whether the excess cortisol originates from external medications or internal pathology. Persistent cortisol elevation alters metabolism, immune function, and endocrine signaling, producing the characteristic clinical features of the... https://www.jove.com/v/40896 79 2026-04-13T21:37:37+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53613.jpg The c-FOS Protein Immunohistological Detection: A Useful Tool As a Marker of Central Pathways Involved in Specific Physiological Responses In Vivo and Ex Vivo Here, we present a protocol based on c-FOS protein immunohistological detection, a classical technique used for the identification of neuronal populations involved in specific physiological responses in vivo and ex vivo. https://www.jove.com/v/53613 344 2016-04-25T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58530.jpg Isolation, Fixation, and Immunofluorescence Imaging of Mouse Adrenal Glands Here we present a method to isolate adrenal glands from mice, fix the tissues, section them, and perform immunofluorescence staining. https://www.jove.com/v/58530 517 2018-10-02T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59016.jpg Primary Culture of Rat Adrenocortical Cells and Assays of Steroidogenic Functions The hormone secreted by the adrenal cortex is vital for animals against stress and diseases. Here, we present a protocol to culture the primary rat adrenal cells. It could be a good in vitro platform for investigating the mechanisms of the reagent of interest in adrenal steroidogenesis and lipid biosynthesis. https://www.jove.com/v/59016 273 2019-03-12T19:30:00+00:00 JoVE no https://visualize.jove.com/2220686-embedding-expert-systems-in-laboratory-information-systems monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13383.jpg Enzyme-Linked Immunosorbent Assay In 1971, Peter Perlman and Eva Engvall developed an Enzyme-linked immunosorbent assay (ELISA or EIA). ELISA differs from western blot in that the assays are conducted in microtiter plates or in vivo rather than on an absorbent membrane. There are many different types of ELISAs, but they all involve an antibody molecule whose constant region binds an enzyme, leaving the variable region free to bind its specific antigen. Enzyme-substrate reaction allows the antigen to be visualized or quantified. https://www.jove.com/v/13383 93 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14126.jpg Nursing Clinical Information System Nursing Clinical Information System (NCIS) A Nursing Clinical Information System (NCIS) is a specialized type of healthcare information system tailored to meet the unique needs of nursing practice. It incorporates the principles of nursing informatics to streamline information management and improve the quality of care delivery. Critical attributes of NCIS include: Efficient Information Management: NCIS is designed to manage patient information efficiently, making it easily accessible to... https://www.jove.com/v/14126 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16045.jpg Classification of Systems-I Linearity is a system property characterized by a direct input-output relationship, combining homogeneity and additivity. Homogeneity dictates that if an input x(t) is multiplied by a constant c, the output y(t) is multiplied by the same constant. Mathematically, this is expressed as: Additivity means that the response to the sum of multiple inputs is the sum of their individual responses. For inputs x1(t) and x2(t) producing outputs y1(t) and y2(t), respectively: Combining homogeneity and... https://www.jove.com/v/16045 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16046.jpg Classification of Systems-II Continuous-time systems have continuous input and output signals, with time measured continuously. These systems are generally defined by differential or algebraic equations. For instance, in an RC circuit, the relationship between input and output voltage is expressed through a differential equation derived from Ohm's law and the capacitor relation, Discrete-time systems have input and output signals at specific intervals, defined at distinct instants by difference equations. An example is a... https://www.jove.com/v/16046 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16098.jpg Electro-mechanical Systems Electromechanical systems are intricate configurations that effectively combine electrical and mechanical elements to achieve a desired outcome. Central to many of these systems is the DC motor, a device that converts electrical energy into mechanical motion, enabling various applications ranging from simple fans to complex robotic mechanisms. A key component of the DC motor is the armature, a rotating circuit positioned within a magnetic field. As an electric current passes through the... https://www.jove.com/v/16098 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18562.jpg Information Processing Approach The information-processing theory of cognitive development centers on fundamental mental processes, including attention, memory, and problem-solving skills. Researchers in this field examine how cognitive abilities, such as working memory, evolve and influence children's overall development. Studies indicate that children with stronger working memory tend to excel in reading comprehension, math, and problem-solving compared to peers with less efficient memory skills. Low working memory is also... https://www.jove.com/v/18562 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63342.jpg Interactive and Visualized Online Experimentation System for Engineering Education and Research This work describes an online experimentation system that provides visualized experiments, including the visualization of theories, concepts, and formulas, visualizing the experimental process with three-dimensional (3-D) virtual test rigs, and visualizing the control and monitoring system using widgets such as charts and cameras. https://www.jove.com/v/63342 515 2021-11-24T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66432.jpg Online Virtual Reality Networked Control Laboratory Applied in Control Engineering Education This study describes a WebVR-based online virtual reality (VR) laboratory system that provides users with immersive and interactive experimentation capabilities supported by VR devices. The proposed system not only helps to enhance the realism of user participation in online experiments but is also applicable to a wide range of online laboratory frameworks. https://www.jove.com/v/66432 255 2024-02-23T22:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68270.jpg Introduction of an Integrated Pathology Image Management, Artificial Intelligence, and Reporting System Integrated image management, artificial intelligence (AI), and reporting systems have revolutionized diagnostic pathology practice. In this paper, we introduce FlexLIS, a state-of-the-art system that enables AI to assist pathologists in performing histopathology image assessments and generating diagnostic reports. https://www.jove.com/v/68270 333 2025-07-11T22:40:00+00:00 JoVE no https://visualize.jove.com/2322271-a-smaller-initial-dose-protects-mice-against-several-lethal-doses-of-ammonium-acetate monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17273/17273_article_thumb_17273.jpg Toxicity Testing in Animals Toxicity tests in animals are grounded on two main assumptions: first, the effects observed in laboratory animals can be extrapolated to humans, especially when adjusted for body surface area; second, high-dose exposure in animals is essential to identify potential human hazards from lower doses. This is based on the quantal dose-response concept, which faces the challenge of extrapolating results from relatively few test animals to much larger human populations. For example, a 0.01% incidence... https://www.jove.com/v/17273 83 2026-02-12T19:17:01+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57570.jpg Intracerebroventricular Treatment with Resiniferatoxin and Pain Tests in Mice The transient receptor potential vanilloid type 1 (TRPV1) in the supraspinal region has been suggested to play some roles in the brain function. Described here is a protocol for intracerebroventricular injection of resiniferatoxin for supraspinal TRPV1 desensitization in mice. Procedures for some pain tests are also presented. https://www.jove.com/v/57570 364 2020-09-02T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58574.jpg A Controlled Mouse Model for Neonatal Polymicrobial Sepsis This protocol provides the necessary steps to establish and evaluate neonatal sepsis in 7-day-old mice. https://www.jove.com/v/58574 894 2019-01-27T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62097.jpg Visualizing Lung Cellular Adaptations during Combined Ozone and LPS Induced Murine Acute Lung Injury Combined ozone and bacterial endotoxin exposed mice show wide-spread cell death, including that of neutrophils. We observed cellular adaptations such as disruption of cytoskeletal lamellipodia, increased cellular expression of complex V ATP synthase subunit β and angiostatin in broncho-alveolar lavage, suppression of the lung immune response and delayed neutrophil recruitment. https://www.jove.com/v/62097 888 2021-03-21T21:00:00+00:00 JoVE no https://visualize.jove.com/2327928-aids-and-salmonella-infected-abdominal-aortic-aneurysm monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1947.jpg Chronic Salmonella Infected Mouse Model Establish a chronic bacterial infected mouse model with persistent Salmonella typhimurium colonization in intestine for 27 weeks. https://www.jove.com/v/1947 541 2010-06-01T00:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16344.jpg Pulmonary Tuberculosis I Tuberculosis, often called TB, is a contagious illness primarily caused by Mycobacterium tuberculosis. It mainly affects the lung parenchyma but can also impact other body parts. Causative Organism The primary infectious agent causing tuberculosis is Mycobacterium tuberculosis, a slow-growing, acid-fast, aerobic rod that exhibits sensitivity to heat and ultraviolet light. Instances of Mycobacterium bovis and Mycobacterium avium contributing to the development of TB infection are rare. Mode of... https://www.jove.com/v/16344 89 JoVE no https://cloudfront.jove.com/files/ftp_upload/17979/17979_article_thumb_17979.jpg Aneurysm I: Introduction An aortic aneurysm is a localized outpouching or dilation at a weak point in the artery wall. It may involve different parts of the aorta, such as the abdominal aorta, aortic arch, or thoracic aorta.Etiological factorsSeveral disorders are associated with aortic aneurysms.Congenital causes, such as primary connective tissue disorders like Marfan syndrome, impact the integrity and strength of connective tissues, notably affecting the aorta. Marfan syndrome is a genetic disorder that specifically... https://www.jove.com/v/17979 90 2025-06-19T16:19:01+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17980/17980_article_thumb_17980.jpg Aneurysm II: Clinical Manifestations and Diagnostic Studies Thoracic, aortic arch and abdominal aneurysms are significant vascular conditions that can present with various clinical manifestations and lead to serious complications. Understanding these manifestations and the appropriate diagnostic studies is essential for effective management and treatment.Thoracic Aortic AneurysmsThoracic aortic aneurysms often remain asymptomatic until they reach a size that impinges on adjacent structures. They typically cause deep, diffuse chest pain that radiates to... https://www.jove.com/v/17980 81 2025-06-19T16:19:14+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17981/17981_article_thumb_17981.jpg Aneurysm III: Interprofessional Care Aneurysm management involves either conservative medical therapy or surgical intervention, depending on the size and symptoms of the aneurysm. Conservative management is generally reserved for smaller, asymptomatic aneurysms, while larger or symptomatic aneurysms often necessitate surgical repair.Conservative Medical TherapyFor small, asymptomatic aneurysms, particularly abdominal aortic aneurysms (AAA) less than 5.5 centimeters in diameter, conservative medical therapy is recommended. This... https://www.jove.com/v/17981 86 2025-06-19T16:19:25+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40808/40808_article_thumb_40808.jpg Reservoir of Infection Infectious diseases arise from intricate interactions between pathogens and their reservoirs. A reservoir of infection refers to the natural habitat where a pathogen lives, grows, and multiplies, serving as a continual source of infection. Reservoirs are broadly classified as either living or nonliving, and each plays a unique role in disease transmission, significantly influencing public health interventions and control strategies.Humans act as reservoirs for a wide array of pathogens,... https://www.jove.com/v/40808 90 2026-03-12T20:36:10+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40856/40856_article_thumb_40856.jpg Amebiasis Entamoeba histolytica, a protozoan parasite, is responsible for intestinal and extraintestinal amebiasis. Though a significant proportion of infections remain asymptomatic, approximately 50 million individuals annually are estimated to present with clinical disease, resulting in up to 100,000 deaths globally. The disease burden is disproportionately high in regions with lower socioeconomic status, such as parts of India, Africa, Mexico, and Latin America.Etiology and TransmissionThe infective... https://www.jove.com/v/40856 88 2026-05-20T21:29:57+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60068.jpg Chronic Salmonella Infection Induced Intestinal Fibrosis This protocol describes a mouse model of Salmonella driven intestinal fibrosis that resembles key pathological hallmarks of Crohn’s disease including transmural inflammation and fibrosis. This method can be used to evaluate host factors that alter fibrotic outcomes using mutant mice maintained on a C57Bl/6 genetic background. https://www.jove.com/v/60068 520 2019-09-22T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63608.jpg Mouse Abdominal Aortic Aneurysm Model Induced by Perivascular Application of Elastase The present protocol describes a standardized surgical method for the elastase-induced AAA model through the direct application of elastase to the adventitia of infrarenal abdominal aorta in mice. https://www.jove.com/v/63608 289 2022-02-11T23:00:00+00:00 JoVE no https://visualize.jove.com/2370871-the-permissive-role-of-glucocorticoids-on-interleukin-1-stimulation-of-angiotensinogen-gene-transcription-is-mediated-by-an-interaction-between-inducible-enhancers monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11605.jpg Cell Specific Gene Expression Multicellular organisms contain a variety of structurally and functionally distinct cell types, but the DNA in all the cells originated from the same parent cells. The differences in the cells can be attributed to the differential gene expression. Liver cells, whose functions include detoxification of blood, production of bile to metabolize fats, and synthesis of proteins essential for metabolism, must express a specific set of genes to perform their functions. Gene expression also varies with... https://www.jove.com/v/11605 118 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11998.jpg NF-κB-dependent Signaling Pathway The transcription factor NF-κB was discovered in 1986 in the lab of Nobel laureate Professor David Baltimore, for its interaction with the immunoglobulin light chain enhancer in B-cells. After more than three decades of study, it is now evident that NF-κB regulates the expression of over 100 genes. Most of these genes play an essential role in the innate and adaptive immune responses as well as the inflammatory responses of animals. NF-κB-dependent Signaling Mechanism The heterodimer of NF-κB... https://www.jove.com/v/11998 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13210.jpg The JAK-STAT Signaling Pathway Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as SH2... https://www.jove.com/v/13210 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13212.jpg TGF - β Signaling Pathway The TGF-β signaling pathway regulates cell growth, differentiation, adhesion, motility, and development. TGF-β ligands that induce TGF-β signaling are synthesized in their latent form. Several proteases or cell surface receptors such as integrins act upon the latent form, releasing the active ligand. There are three types of mammalian TGF-βs: (TGF-β1, TGF-β2, and TGF-β3) that bind as homodimers or heterodimers to TGF-β receptors. The TGF-β receptors are of three kinds RI, RII, and RIII. The RI... https://www.jove.com/v/13212 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13324.jpg GPCRs Regulate Adenylyl Cylase Activity Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of cells. Two... https://www.jove.com/v/13324 69 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13325.jpg cAMP-dependent Protein Kinase Pathways Cyclic Adenosine Monophosphate (cAMP) is an essential second messenger that activates protein kinase A (PKA) and regulates various biological processes. A single epinephrine molecule binds to GPCR and activates several heterotrimeric G proteins, each stimulating multiple adenylyl cyclase, amplifying the signal, and synthesizing large numbers of cAMP molecules. Small changes in cAMP concentration affect PKA activity. The binding of four cAMP molecules induces a conformational change in PKA,... https://www.jove.com/v/13325 85 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53191.jpg Subcutaneous Angiotensin II Infusion using Osmotic Pumps Induces Aortic Aneurysms in Mice Subcutaneous implantation of osmotic pumps provides a convenient approach for prolonged and consistent delivery of compounds. This approach has been used extensively to study both abdominal and thoracic aortic aneurysms in mice. https://www.jove.com/v/53191 441 2015-09-28T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53978.jpg Prediction and Validation of Gene Regulatory Elements Activated During Retinoic Acid Induced Embryonic Stem Cell Differentiation In this work we provide an experimental workflow of how active enhancers can be identified and experimentally validated. https://www.jove.com/v/53978 547 2016-06-21T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59394.jpg Inducible, Cell Type-Specific Expression in Arabidopsis thaliana Through LhGR-Mediated Trans -Activation Here, we describe the generation and application of a set of transgenic Arabidopsis thaliana lines enabling inducible, tissue-specific expression in the three main meristems, the shoot apical meristem, the root apical meristem, and the cambium. https://www.jove.com/v/59394 571 2019-04-19T22:00:00+00:00 JoVE no https://visualize.jove.com/2403614-cutaneous-alternaria-infection-in-a-patient-on-chronic-corticosteroids monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14003.jpg Skin Diseases and Disorders Skin is the first line of defense and encounters a variety of microbes. Some pathogenic strains are often the cause of a broad range of infections of the skin and other body systems. These conditions can affect people of all ages and may have different causes, including genetic factors, infections, autoimmune reactions, environmental factors, and lifestyle choices. Gram-positive Staphylococcus spp. and Streptococcus spp. are responsible for many of the most common skin infections. However, many... https://www.jove.com/v/14003 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14004.jpg Skin Cancer Skin cancer is a type of cancer that occurs when there is an abnormal growth of skin cells, usually triggered by damage to the DNA within the skin cells. It is primarily caused by exposure to ultraviolet (UV) radiation from the sun or artificial sources like tanning beds. Skin cancer is the most common type of cancer worldwide, and its incidence continues to rise. Basal Cell Carcinoma (BCC): BCC is the most common type of skin cancer, accounting for about 80% of cases. It typically develops in... https://www.jove.com/v/14004 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15233.jpg Antiasthma Drugs: Inhaled Corticosteroids and Glucocorticoids Inhaled corticosteroids (ICS) are anti-inflammatory drugs used primarily in treating persistent asthma and providing long-term maintenance. They target the bronchial mucosa, the lining of the airways, to control inflammation, a critical factor in asthma progression and exacerbation. ICS work through a multifaceted mechanism of action. They suppress the inflammatory response caused by the proliferation of TH cells. They also reduce the transcription of the IL-2 gene, which is involved in the... https://www.jove.com/v/15233 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16344.jpg Pulmonary Tuberculosis I Tuberculosis, often called TB, is a contagious illness primarily caused by Mycobacterium tuberculosis. It mainly affects the lung parenchyma but can also impact other body parts. Causative Organism The primary infectious agent causing tuberculosis is Mycobacterium tuberculosis, a slow-growing, acid-fast, aerobic rod that exhibits sensitivity to heat and ultraviolet light. Instances of Mycobacterium bovis and Mycobacterium avium contributing to the development of TB infection are rare. Mode of... https://www.jove.com/v/16344 89 JoVE no https://cloudfront.jove.com/files/ftp_upload/40819/40819_article_thumb_40819.jpg Staphylococcal Skin Infections Staphylococcus aureus is a Gram-positive coccus that resides harmlessly on the skin and mucous membranes of healthy individuals. When the skin barrier is breached, it can shift from a commensal to an opportunistic pathogen. This transition is facilitated by surface adhesins, such as clumping factor B and S. aureus surface protein G (SasG), which bind to structural proteins, including loricrin and cytokeratin, in the damaged epidermis. Protein A, another key factor, binds the Fc region of... https://www.jove.com/v/40819 89 2026-03-12T20:35:44+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40857/40857_article_thumb_40857.jpg Candidiasis Candidiasis is a fungal infection caused by opportunistic species of Candida. It can affect various anatomical sites, including the skin, oral cavity, nails, and genitourinary tract. Among its forms, vaginal candidiasis is the most common type of mucosal infection. It typically results from the overgrowth of Candida albicans in the vaginal mucosa. Under normal conditions, C. albicans exists as a commensal organism within the vaginal microbiota, regulated by the dominance of lactobacilli, which... https://www.jove.com/v/40857 80 2026-05-20T21:31:18+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50509.jpg The Goeckerman Regimen for the Treatment of Moderate to Severe Psoriasis Psoriasis is a chronic, immune-mediated inflammatory skin disease. The Goeckerman regimen, formulated for the treatment of psoriasis, consists of exposure to ultraviolet B (UVB) light and application of crude coal tar (CCT). The following protocol is for the administration of Goeckerman therapy for the treatment of moderate-to-severe psoriasis. https://www.jove.com/v/50509 699 2013-07-11T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57574.jpg Deep Dermal Injection As a Model of Candida albicans Skin Infection for Histological Analyses Here we describe a protocol that allows histological and molecular analysis of skin samples after Candida albicans intradermal injection. This protocol maintains the structural integrity of the skin and allows for the localization of tissue-resident or newly recruited immune cells as well as the pathogen distribution. https://www.jove.com/v/57574 645 2018-06-13T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66430.jpg Examination of Oral Candida Infection in Primary Sjögren's Syndrome Patients Here, we present a protocol for the examination of oral Candida infection in patients with primary Sjögren's syndrome, which can be used for timely treatment and, thereafter, avoiding related complications. https://www.jove.com/v/66430 326 2024-03-01T22:25:00+00:00 JoVE no https://visualize.jove.com/2437397-effects-of-an-angiotensin-converting-enzyme-ace-inhibitor-sa446-on-tissue-ace-activity-in-normotensive-spontaneously-hypertensive-and-renal-hypertensive-rats monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15020.jpg Antihypertensive Drugs: Action of β 1 Blockers β1-receptors are primarily located in the heart and kidneys. In cardiac myocytes, these receptors interact with neurotransmitters released by the sympathetic nervous system during heightened activity or danger. As a result, β1-receptors get activated, initiating a series of biochemical processes. Excessive activation of beta receptors due to chronic stress can abnormally increase heart rate and contractility, resulting in high blood pressure or hypertension. To counteract this, β1-blockers... https://www.jove.com/v/15020 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15023.jpg Antihypertensive Drugs: Angiotensin-Converting Enzyme Inhibitors Angiotensin-converting enzyme (ACE), a vital component of the renin-angiotensin-aldosterone system, is abundant in lung endothelial cells. ACE converts the inactive decapeptide, angiotensin I, into the active octapeptide, angiotensin II. This potent vasoconstrictor narrows blood vessels, increasing resistance to blood flow and elevating blood pressure. Angiotensin II also stimulates aldosterone production, encouraging kidney cells to reabsorb more sodium and water from urine, thereby increasing... https://www.jove.com/v/15023 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15024.jpg Antihypertensive Drugs: Angiotensin II Receptor Blockers In the renin-angiotensin-aldosterone system, a hormone called angiotensin II plays a crucial role. It binds to the AT1 receptors in vascular smooth muscles coupled with Gq proteins. The activation of these receptors activates an enzyme called phospholipase C, which releases two molecules: inositol trisphosphate and diacylglycerol. These molecules cause a chain reaction that leads to the phosphorylation of myosin light chains and promotes interaction between actin and myosin, leading to smooth... https://www.jove.com/v/15024 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15025.jpg Antihypertensive Drugs: Direct Renin Inhibitors The renin-angiotensin-aldosterone system (RAAS) is an intricate physiological pathway involving numerous enzymes and hormones, including renin, angiotensin-converting enzyme (ACE), angiotensin I and II, and aldosterone. Imbalances within this system increase the production of angiotensin II and aldosterone. Increased angiotensin II levels promote vasoconstriction and blood pressure elevation. Concurrently, higher aldosterone levels stimulate sodium and water reabsorption in the kidneys,... https://www.jove.com/v/15025 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15037.jpg Heart Failure Drugs: Inhibitors of Renin-Angiotensin System The activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) contributes to cardiac remodeling, and inhibiting the RAAS is a pharmacological target in heart failure management. As a result, neurohumoral modulation is a crucial treatment principle for managing heart failure. This approach involves using medications like ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), β-blockers, mineralocorticoid receptor antagonists (MRAs), and neutral... https://www.jove.com/v/15037 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/17966/17966_article_thumb_17966.jpg Hypertension II: Pathophysiology Hypertension is a chronic condition in which the blood's force against artery walls is excessively high, posing risks such as heart disease. The condition's underlying mechanisms involve complex interactions among the cardiovascular, kidney, and autonomic nervous systems.Renin-Angiotensin-Aldosterone System (RAAS): This system significantly influences blood pressure regulation. When blood pressure decreases, the kidneys secrete renin. This enzyme transforms angiotensinogen, a plasma protein,... https://www.jove.com/v/17966 89 2025-06-19T16:16:31+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61058.jpg A Modified Two Kidney One Clip Mouse Model of Renin Regulation in Renal Artery Stenosis A modified 2 kidney 1 clip (2K1C) Goldblatt mouse model was developed using polyurethane tubing to initiate renal artery stenosis, inducing an increase in renin expression and kidney injury. Here, we describe a detailed procedure of preparing and placing the cuff onto the renal artery to generate a reproducible and consistent 2K1C mouse model. https://www.jove.com/v/61058 501 2020-10-26T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63719.jpg Improved Renal Denervation Mitigated Hypertension Induced by Angiotensin II Infusion Here, we present a protocol for renal sympathetic denervation (RDN) in mice with hypertension induced by Angiotensin II infusion. The procedure is repeatable, convenient and allows to study the regulatory mechanisms of RDN on hypertension and cardiac hypertrophy. https://www.jove.com/v/63719 515 2022-05-26T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65932.jpg The Antihypertensive Effects and Mechanisms of Huotan Jiedu Tongluo Decoction in Rats with H-Type Hypertension Here, we present a protocol to induce H-type hypertension and evaluate the antihypertensive effects of Huotan Jiedu Tongluo decoction (HTJDTLD) administered intragastrically. In rats with H-type hypertension, HTJDTLD had effective antihypertensive effects, possibly associated with inhibition of endoplasmic reticulum (ER) stress-induced apoptosis pathway activation. https://www.jove.com/v/65932 357 2024-05-17T20:20:00+00:00 JoVE no https://visualize.jove.com/2457309-amsacrine-is-safe-in-patients-with-ventricular-ectopy monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1730.jpg Programmed Electrical Stimulation in Mice Programmed electrical stimulation provides the ability to determine conduction properties of the heart, and the possibility to induce and terminate cardiac arrhythmias using various pacing protocols. Using a transvenous catheter, intracardiac electrogram recordings can be obtained in mice following programmed electrical stimulation protocols to identify arrhythmogenic substrates. https://www.jove.com/v/1730 449 2010-05-27T00:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15029.jpg Antiarrhythmic Drugs: Class I Agents as Sodium Channel Blockers Class I antiarrhythmic drugs are used to treat various types of arrhythmias or irregular heart rhythms. These drugs block the sodium (Na+) channels in the cardiac cells, thereby affecting the movement of electrical impulses across the heart. Class I antiarrhythmic drugs are divided into three subgroups: Class IA, Class IB, and Class IC, each with distinct mechanisms of action and effects on the heart. Class 1A Antiarrhythmic Drugs: These drugs work by moderately blocking sodium channels,... https://www.jove.com/v/15029 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15035.jpg Heart Failure Drugs: Inotropic Agents Positive inotropic agents are commonly used as the first line of treatment for heart failure. One such agent is digoxin, derived from the genus Digitalis, which has been known for centuries but effectively utilized since 1785. However, these cardiac glycosides can have potentially toxic effects due to their mechanism of action, which involves inhibiting Na+/K+-ATPase and increasing contractility. Digoxin is absorbed orally and distributed in various tissues, including the CNS. It has a long... https://www.jove.com/v/15035 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/17943/17943_article_thumb_17943.jpg Dysrhythmias VI: Management of Dysrhythmias Dysrhythmia management involves a multifaceted approach, incorporating pharmacological treatments, medical procedures, surgical interventions, lifestyle modifications, and patient education.Pharmacological ManagementAntiarrhythmic Drugs:Class I (Sodium Channel Blockers): This class includes quinidine and procainamide, which reduce the speed of impulse conduction in the heart, stabilize the cardiac membrane, and control arrhythmias. Quinidine and procainamide are Class IA agents that prolong the... https://www.jove.com/v/17943 85 2025-06-19T16:37:04+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17949/17949_article_thumb_17949.jpg Cardiopulmonary Resuscitation IV: Pharmacological Management Pharmacologic intervention is crucial in treating cardiac arrest patients during ACLS or Advanced Cardiovascular Life Support. The ACLS algorithms guide the administration of specific drugs based on the patient's cardiac arrest rhythm, which includes pulseless ventricular tachycardia (VT), ventricular fibrillation (VF), asystole, and pulseless electrical activity (PEA).EpinephrineIndication: Epinephrine is the first-line drug for all cardiac arrest rhythms.Mechanism of Action: Epinephrine... https://www.jove.com/v/17949 85 2025-07-31T20:24:37+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17960/17960_article_thumb_17960.jpg Cardiomyopathy III: Hypertrophic Cardiomyopathy Hypertrophic cardiomyopathy, or HCM, is an autosomal dominant genetic disorder characterized by asymmetric left ventricular hypertrophy without ventricular dilation. It is more common in men and is typically diagnosed in young, athletic adults.EtiologyHCM is primarily genetic and is caused by mutations in genes encoding sarcomeric proteins. Researchers have identified over 1400 mutations across at least 11 different genes. Among these, the most frequently occurring mutations are found in the... https://www.jove.com/v/17960 89 2025-08-11T17:09:32+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18437/18437_article_thumb_18437.jpg ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias Arrhythmia is a condition characterized by an irregular heart rhythm, with ECG changes that differ based on its origin and nature. The types of arrhythmias discussed below include atrial, junctional, and ventricular arrhythmias.Atrial ArrhythmiasPremature Atrial Complexes (PACs): PACs are early atrial beats caused by stress, caffeine, alcohol, electrolyte imbalances, hypoxia, hyperthyroidism, or certain medications (e.g., bronchodilators and decongestants). The ECG shows early P waves with an... https://www.jove.com/v/18437 85 2025-06-19T16:15:27+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63094.jpg Sterile Pericarditis in Aachener Minipigs As a Model for Atrial Myopathy and Atrial Fibrillation We describe a sterile pericarditis model in minipigs to study atrial myopathy and atrial fibrillation (AF). We present surgical and anesthetic techniques, strategies for vascular access, and a protocol to study the inducibility of AF. https://www.jove.com/v/63094 536 2021-09-24T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63597.jpg Cox-Maze IV Procedure Concomitant with Valvular Surgery In Situs Inversus Dextrocardia: A Single-Center Experience in China We summarize the Cox-Maze IV procedure concomitant with valvular surgery performed in patients with situs inversus dextrocardia at this institution. https://www.jove.com/v/63597 522 2022-02-11T22:45:00+00:00 JoVE no https://visualize.jove.com/2486500-dynamic-organization-of-intersensory-function monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10859.jpg Somatosensation The somatosensory system relays sensory information from the skin, mucous membranes, limbs, and joints. Somatosensation is more familiarly known as the sense of touch. A typical somatosensory pathway includes three types of long neurons: primary, secondary, and tertiary. Primary neurons have cell bodies located near the spinal cord in groups of neurons called dorsal root ganglia. The sensory neurons of ganglia innervate designated areas of skin called dermatomes. In the skin, specialized... https://www.jove.com/v/10859 93 2025-10-23T18:49:22+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14907.jpg Motor and Sensory Areas of the Cortex The cerebral cortex, the brain's outermost layer, is pivotal in processing complex cognitive tasks, emotions, and various sensory inputs and executing voluntary motor activities. This intricate structure is divided into three primary functional areas: the motor areas, sensory areas, and association areas. Motor Areas The motor areas located in the frontal lobe are central to controlling voluntary movements. This region is further subdivided into the primary motor cortex and the premotor cortex. https://www.jove.com/v/14907 74 2025-06-13T16:10:51+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14908.jpg Association Areas of the Cortex Association areas are regions of the cerebral cortex that do not have a specific sensory or motor function. Instead, they integrate and interpret information from various sources to enable higher cognitive processes such as memory, learning, and decision-making. Some key association areas include the following: Prefrontal Association Area: This area is located in the frontal lobe and is involved in planning, decision-making, and moderating social behavior. It connects with primary motor areas,... https://www.jove.com/v/14908 81 2025-06-13T16:11:09+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14933.jpg Sensory Perception: Organization of the Somatosensory System The somatosensory system is the central and peripheral nervous system component that senses and processes touch, pressure, pain, temperature, and body position or proprioception. The process of sensation takes place at three levels: The receptor level: The receptor level is the first stage of sensation. It involves the detection of a stimulus by specialized sensory receptors. The stimulus must arrive within the receptor's receptive field. Next, the receptor converts the energy of the stimulus... https://www.jove.com/v/14933 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17746.jpg Organization of the Brain The brain is an integral component of the nervous system and serves as the center for processing sensory inputs, making decisions, and directing bodily actions. This complex organ is organized into three primary sections: the hindbrain, midbrain, and forebrain, each responsible for a range of vital functions. Hindbrain The hindbrain, located at the base of the brain, plays a vital role in regulating automatic processes that sustain life. It includes the medulla oblongata, which is essential for... https://www.jove.com/v/17746 91 2026-06-29T19:11:34+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17749.jpg Somatosensory, Motor, and Association Cortex The somatosensory cortex in the parietal lobes is crucial for interpreting sensory data such as touch, temperature, and proprioception. The somatosensory cortex, situated in the parietal lobes, plays a vital role in interpreting sensory information like touch, temperature, and proprioception—awareness of body position. This specialized brain region features an organized structure wherein neurons at the top primarily process sensations originating from the lower body. In contrast, those at the... https://www.jove.com/v/17749 83 2026-03-20T20:23:54+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51422.jpg Methods to Explore the Influence of Top-down Visual Processes on Motor Behavior It is unclear how top-down signals from the ventral visual stream affect movement. We developed a paradigm to test motor behavior towards a target on a 3D depth inversion illusion. Significant differences are reported in both deliberate, goal-directed movements and automatic actions under illusory and veridical viewing conditions. https://www.jove.com/v/51422 589 2014-04-16T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52677.jpg Testing Sensory and Multisensory Function in Children with Autism Spectrum Disorder We describe how to implement a battery of behavioral tasks to examine the processing and integration of sensory stimuli in children with ASD. The goal is to characterize individual differences in temporal processing of simple auditory and visual stimuli and relate these to higher order perceptual skills like speech perception. https://www.jove.com/v/52677 553 2015-04-22T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59575.jpg Using the Race Model Inequality to Quantify Behavioral Multisensory Integration Effects The current study aims to provide a step-by-step tutorial for calculating the magnitude of multisensory integration effects in an effort to facilitate the production of translational research studies across diverse clinical populations. https://www.jove.com/v/59575 493 2019-05-10T21:45:00+00:00 JoVE no https://visualize.jove.com/2655647-expert-systems-in-histopathology-i-introduction-and-overview monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13393.jpg Immunocytochemistry and Immunohistochemistry Immunocytochemistry (ICC) and immunohistochemistry (IHC) are techniques that use antibodies to check for specific proteins or antigens in a sample. The technique was first published by Albert Coons in 1941 to detect the presence of pneumococcal antigen in tissue sections from mice infected with Pneumococcus. Immunocytochemistry helps localization of proteins or antigens in individual cells like blood cells, stem cells, etc., while immunohistochemistry does the same for tissue samples. These... https://www.jove.com/v/13393 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13965.jpg Classification of Epithelial Tissues: Overview Epithelial tissues are classified according to the shape of the cells and the number of cell layers formed. Cell shapes can be squamous (flattened and thin), cuboidal (square-like, as wide as it is tall), or columnar (rectangular, taller than it is wide). Additionally, the nucleus shape helps identify the type of epithelial cells. Squamous cells have flattened disc-shaped nuclei, cuboidal cells have spherical nuclei, and columnar cells have elongated nuclei. Based on the number of cell layers,... https://www.jove.com/v/13965 82 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53837.jpg Quantitation of Protein Expression and Co-localization Using Multiplexed Immuno-histochemical Staining and Multispectral Imaging Immunohistochemistry is a powerful lab technique for evaluating protein localization and expression within tissues. Current semi-automated methods for quantitation introduce subjectivity and often create irreproducible results. Herein, we describe methods for multiplexed immunohistochemistry and objective quantitation of protein expression and co-localization using multispectral imaging. https://www.jove.com/v/53837 520 2016-04-08T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58654.jpg Using Robotic Systems to Process and Embed Colonic Murine Samples for Histological Analyses Lack of standardization for murine tissue processing reduces the quality of murine histopathological analysis as compared to human specimens. Here, we present a protocol to perform histopathological examination of murine inflamed and uninflamed colonic tissues to show the feasibility of robotic systems routinely used for processing and embedding human samples. https://www.jove.com/v/58654 333 2019-01-07T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68270.jpg Introduction of an Integrated Pathology Image Management, Artificial Intelligence, and Reporting System Integrated image management, artificial intelligence (AI), and reporting systems have revolutionized diagnostic pathology practice. In this paper, we introduce FlexLIS, a state-of-the-art system that enables AI to assist pathologists in performing histopathology image assessments and generating diagnostic reports. https://www.jove.com/v/68270 333 2025-07-11T22:40:00+00:00 JoVE no https://visualize.jove.com/2670682-structure-and-expression-in-escherichia-coli-k-12-of-the-l-asparaginase-i-encoding-ansa-gene-and-its-flanking-regions monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4056.jpg Mapping Bacterial Functional Networks and Pathways in Escherichia Coli using Synthetic Genetic Arrays Systematic, large-scale synthetic genetic (gene-gene or epistasis) interaction screens can be used to explore genetic redundancy and pathway cross-talk. Here, we describe a high-throughput quantitative synthetic genetic array screening technology, termed eSGA that we developed for elucidating epistatic relationships and exploring genetic interaction networks in Escherichia coli. https://www.jove.com/v/4056 846 2012-11-12T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10984.jpg Operons Prokaryotes can control gene expression through operons—DNA sequences consisting of regulatory elements and clustered, functionally related protein-coding genes. Operons use a single promoter sequence to initiate transcription of a gene cluster (i.e., a group of structural genes) into a single mRNA molecule. The terminator sequence ends transcription. An operator sequence, located between the promoter and structural genes, prohibits the operon’s transcriptional activity if bound by a repressor... https://www.jove.com/v/10984 129 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12034.jpg Reporter Genes Reporter genes are a type of protein-coding gene that are often tagged to a gene of interest. Once inside a target cell, reporter genes usually produce visually identifiable characteristics like fluorescence and luminescence when expressed along with the gene of interest. Thus, reporter genes “report” the presence or absence of genes of interest in an organism, determine the gene expression pattern, or track the physical location of a DNA segment or protein in the cell. Commonly used reporter... https://www.jove.com/v/12034 131 JoVE no https://cloudfront.jove.com/files/ftp_upload/19524/19524_article_thumb_19524.jpg Prokaryotic Gene Structure and Organization Prokaryotic genomes exhibit a streamlined organization of coding and non-coding regions essential for gene expression and protein synthesis. While coding regions contain the genetic instructions for proteins or functional RNAs, non-coding regions regulate the precise transcription and translation of these genes.Coding Regions: Proteins and RNAsThe primary coding regions, known as structural genes, include sequences transcribed into messenger RNA (mRNA) and ultimately translated into... https://www.jove.com/v/19524 88 2025-06-12T15:55:52+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19532/19532_article_thumb_19532.jpg Operon Model The operon model represents a fundamental mechanism of gene regulation in prokaryotes, enabling coordinated expression of genes involved in related metabolic or functional pathways. Operons consist of structural genes, a promoter, and an operator, with transcription regulated by repressors, activators, and small effector molecules.Structure and Function of OperonsAn operon is a cluster of structural genes transcribed together under the control of a single promoter. The promoter region... https://www.jove.com/v/19532 83 2025-06-12T16:14:08+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19533/19533_article_thumb_19533.jpg Inducible Operons: lac Operon The lac operon in Escherichia coli is a model for understanding inducible gene regulation and metabolic flexibility. It integrates local control by lactose and global regulation through catabolite repression, enabling E. coli to preferentially metabolize glucose when available and switch to lactose utilization when glucose is scarce.Structure and Function of the lac OperonThe lac operon contains three structural genes: lacZ (β-galactosidase), lacY (lactose permease), and lacA (thiogalactoside... https://www.jove.com/v/19533 85 2025-06-12T16:14:20+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19541/19541_article_thumb_19541.jpg Stringent Response in E. coli Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs... https://www.jove.com/v/19541 83 2025-06-12T16:16:17+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59055.jpg A Fluorescence-based Method to Study Bacterial Gene Regulation in Infected Tissues Described here is a method for analyzing bacterial gene expression in animal tissues at a cellular level. This method provides a resource for studying the phenotypic diversity occurring within a bacterial population in response to the tissue environment during an infection. https://www.jove.com/v/59055 430 2019-02-19T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/70209.jpg Site-Specific Lysine Lactylation via Genetic Code Expansion in E. coli and Mammalian Cells This study established a method that utilizes genetic code expansion to successfully incorporate lactyl-lysine (Klac) at specific sites of the human enolase-1 (hENO1) and superfolder GFP (sfGFP) in Escherichia coli and mammalian cells. https://www.jove.com/v/70209 358 2026-02-24T21:25:00+00:00 JoVE no https://visualize.jove.com/2671271-alarms-and-their-limits-in-monitoring monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13313.jpg Errors occurring during blood pressure monitoring Blood pressure monitoring is a crucial clinical procedure in diagnosing and managing various cardiovascular conditions. Despite its significance, the accuracy of blood pressure measurements can be compromised by multiple factors, potentially leading to either falsely high or low readings. These inaccuracies are critical as they can significantly impact patient care. So, it is vital to understand these challenges deeply and adopt strategic approaches to minimize errors. Several factors... https://www.jove.com/v/13313 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14521.jpg Difference from Background: Limit of Detection The limit of detection (LOD) is the smallest amount of analyte that can be distinguished from the background noise. The LOD value corresponds to the concentration at which the analyte signal is three times larger than the standard deviation of the blank signal. Below this value, the analyte signal cannot be differentiated from the background noise. It is calculated by dividing the calibration slope by 3 times the standard deviation of the blank signals. The LOD indicates the presence or absence... https://www.jove.com/v/14521 65 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14790.jpg Gas Chromatography: Overview of Detectors Detectors in gas chromatography (GC) help identify and quantify the components of a mixture by translating chemical properties into measurable signals, which are displayed on a chromatogram. Detectors can be categorized into two main types: destructive and non-destructive. A non-destructive detector allows a sample to be analyzed without altering or consuming it, meaning the sample can be collected after detection for further analysis. Examples include thermal conductivity detectors and... https://www.jove.com/v/14790 73 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15076.jpg Operational Amplifiers The operational amplifier, often referred to as an op-amp, is a multifaceted building block of a circuit. This electronic component functions like a voltage-controlled voltage source and can also be used to create a voltage- or current-controlled current source. The design of an operational amplifier enables it to execute mathematical operations when external components like resistors and capacitors are linked to its terminals. An op-amp has the capacity to sum signals, amplify a signal,... https://www.jove.com/v/15076 77 JoVE no https://cloudfront.jove.com/files/ftp_upload/17887/17887_article_thumb_17887.jpg Holter Monitor: 24-Hour Monitoring Holter monitoring is a continuous electrocardiography (ECG) recording that tracks the heart's electrical activity over an extended period, generally 24 to 48 hours. This noninvasive diagnostic tool detects irregular heart rhythms that may not be captured during a standard ECG performed in a clinical setting.DeviceThe Holter monitor is a portable, small device connected to several electrodes on the patient's chest. These electrodes detect the heart's electrical signals and transmit them to the... https://www.jove.com/v/17887 83 2025-06-19T16:09:27+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40101/40101_article_thumb_40101_TN.jpg Types of Limits I Limits are a key mathematical concept for understanding how functions behave as their input approaches specific values, particularly when the function is undefined. They help reveal trends and discontinuities by examining the values a function approaches rather than its actual value.One-sided limits focus on the direction from which a value is approached. When a function behaves differently depending on whether the input approaches from the left or the right, the two one-sided limits may not... https://www.jove.com/v/40101 83 2025-11-26T13:43:43+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56036.jpg Continuous Instream Monitoring of Nutrients and Sediment in Agricultural Watersheds With the advancement of technology and the rise in end-user expectations, the need and use of higher temporal resolution data for pollutant load estimation has increased. This protocol describes a method for continuous in situ water quality monitoring to obtain higher temporal resolution data for informed water resource management decisions. https://www.jove.com/v/56036 770 2017-09-26T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57928.jpg A Video Surveillance System to Monitor Breeding Colonies of Common Terns ( Sterna Hirundo ) This paper describes a protocol that uses a remote video monitoring surveillance system to continuously monitor breeding colonies of ground-nesting waterbirds. The system includes five cameras monitoring individual nests and one camera monitoring the colony as a whole, and is powered by car batteries that are recharged via solar panels. https://www.jove.com/v/57928 459 2018-07-22T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58834.jpg Using a Real-Time Locating System to Measure Walking Activity Associated with Wandering Behaviors Among Institutionalized Older Adults This paper discusses the use of a continuous and objective real-time locating system to measure walking activity associated with wandering behaviors, focusing on older adults with cognitive impairment. Walking activity is measured by walking distance, sustained walking distance, and sustained gait speed. Also assessed are gait quality and balance ability. https://www.jove.com/v/58834 253 2019-02-08T21:30:00+00:00 JoVE no https://visualize.jove.com/2675802-alpha-aminoisobutyric-acid-transport-in-isolated-rat-submandibular-salivary-acinar-cells monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11879.jpg ABC Transporters: Importer ATP-binding cassette or ABC transporters are a class of ATP-driven pumps that hydrolyze ATP to move solutes across the membrane. They can be grouped into importers and exporters. While exporters are present in all domains of life, importers exist only in bacteria and some plants. In bacteria, based on the number of transmembrane helices and the chemical nature of their substrates, the ABC importers can be divided into three types: Type I imports mostly metabolites such as sugars and amino... https://www.jove.com/v/11879 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11892.jpg Overview of Secretory Vesicles Secretory vesicles, also known as dense core vesicles (DCVs), are membrane-bound vesicles that transport secretory proteins, such as hormones or neurotransmitters. Regulated secretory vesicles transport proteins from the trans-Golgi network to the exterior of the cell. Proteins present in regulated secretory vesicles are required to be rapidly exocytosed in large amounts upon a specific stimulus. Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins... https://www.jove.com/v/11892 93 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16512.jpg Methods for Studying Drug Absorption: In situ In situ experiments, such as the Doluisio method and Single-Pass Perfusion technique, provide critical insights into drug uptake by simulating in vivo conditions for drug absorption. The Doluisio method involves perfusing a prepared segment of a rat's small intestine with a solution of radiolabeled drug and a non-absorbable marker. This helps to differentiate between absorbed and non-absorbed drug concentrations. The intestinal segment is connected at both ends using tubing and syringes,... https://www.jove.com/v/16512 69 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51799.jpg Assessing the Secretory Capacity of Pancreatic Acinar Cells Isolated pancreatic acini retain their in vivo morphology and activity and offer powerful ways for monitoring and manipulating secretion. This work demonstrates how acini can be isolated from the mouse pancreas, and how their secretory capacities can be assessed. https://www.jove.com/v/51799 592 2014-08-28T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60009.jpg Characterization of Membrane Transporters by Heterologous Expression in E. coli and Production of Membrane Vesicles We describe a method for the characterization of proton-driven membrane transporters in membrane vesicle preparations produced by heterologous expression in E. coli and lysis of cells using a French press. https://www.jove.com/v/60009 796 2019-12-31T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66882.jpg Demonstration of Membrane Transport of Histidine using Goat Intestinal Inverted Sacs: An Experiential Pedagogical Tool for Undergraduates Here, we report an inexpensive and reproducible method demonstrating the membrane transport of histidine in a goat intestine. This process occurs by co-transporting histidine and sodium ions enabled by the sodium gradient across the enterocyte membrane. This method exploits experiential learning pedagogy to better understand solute movement across biological membranes. https://www.jove.com/v/66882 280 2024-10-04T20:45:00+00:00 JoVE no https://visualize.jove.com/2699761-intracellular-events-associated-with-autonomic-stimulation-of-salivary-secretion monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10835.jpg Neural Regulation Digestion begins with a cephalic phase that prepares the digestive system to receive food. When our brain processes visual or olfactory information about food, it triggers impulses in the cranial nerves innervating the salivary glands and stomach to prepare for food. The cephalic phase is a conditioned or learned response to familiar foods. Our appetite or desire for a particular food modifies the preparatory responses directed by the brain. Individuals may produce more saliva and stomach... https://www.jove.com/v/10835 97 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10840.jpg The Sympathetic Nervous System Overview The sympathetic nervous system—one of the two major divisions of the autonomic nervous system—is activated in times of stress. It prepares the body to meet the challenges of a demanding circumstance while inhibiting essential body functions—such as digestion—that are a lower priority at the moment. The “Fight or Flight” System As a student, you may have had the experience of walking into class and finding a surprise exam that you were not expecting. In the moment of realization, you... https://www.jove.com/v/10840 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14947.jpg Autonomic Nervous System The autonomic nervous system (ANS) is a critical component of the peripheral nervous system, primarily responsible for regulating involuntary bodily functions and maintaining homeostasis. It functions in tandem with the central nervous system (CNS) to seamlessly coordinate various physiological processes without the need for conscious control. The ANS comprises two main divisions: the sympathetic and parasympathetic divisions. These divisions function antagonistically to maintain a dynamic... https://www.jove.com/v/14947 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14951.jpg Sympathetic Signaling Sympathetic signaling, a vital part of the autonomic nervous system, plays a crucial role in mobilizing the body's resources in response to stress or emergencies. It involves the transmission of nerve impulses from sympathetic preganglionic fibers to postganglionic fibers. This results in the release of specific neurotransmitters and activation of adrenergic receptors. Sympathetic preganglionic fibers release the neurotransmitter acetylcholine (ACh) onto the ganglionic neurons in the... https://www.jove.com/v/14951 91 2025-08-12T19:30:45+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14952.jpg Sympathetic Activation The sympathetic division can influence tissues and organs by releasing norepinephrine at peripheral synapses and distributing epinephrine and norepinephrine through the bloodstream. In times of crisis or stress, sympathetic activation occurs, which is regulated by sympathetic centers in the hypothalamus. As a result, sympathetic activation prepares the body for physical exertion, rapid ATP production, and heightened alertness, allowing individuals to respond effectively to challenging or... https://www.jove.com/v/14952 76 2025-08-12T19:29:47+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16187.jpg Salivary Glands and Saliva The salivary glands, of which there are three pairs known as the parotid, submandibular, and sublingual glands, play a crucial role in maintaining oral health and initiating the digestive process. Positioned near the ears, beneath the masseter muscle, the parotid glands secrete saliva into the oral cavity through the parotid duct of Stensen. Meanwhile, the submandibular glands, located on the floor of the mouth, secrete saliva through channels named submandibular ducts. The sublingual glands,... https://www.jove.com/v/16187 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57203.jpg A Method for the Measurement of Salivary Gland Function in Mice Salivary gland hypofunction is a frequent consequence of autoimmune disease and radiation therapy. Reproducible evaluation of salivary gland function in mouse models of these diseases is a technical challenge. Here, a simple method for accurate and reproducible measurement of saliva production in mice is described. https://www.jove.com/v/57203 449 2018-01-25T22:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57283.jpg Preparation of Murine Submandibular Salivary Gland for Upright Intravital Microscopy We describe a protocol to surgically expose and stabilize the murine submandibular salivary gland for intravital imaging using upright intravital microscopy. This protocol is easily adaptable to other exocrine glands of the head and neck region of mice and other small rodents. https://www.jove.com/v/57283 493 2018-05-07T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65819.jpg Interrogating Cell-Cell Interactions in the Salivary Gland via Ex Vivo Live Cell Imaging Immunofluorescent imaging is constrained by the ability to observe complex, time-dependent biological processes in just a single snapshot in time. This study outlines a live-imaging approach conducted on precision-cut mouse submandibular gland slices. This approach allows for the real-time observation of cell-cell interactions during homeostasis and the processes of regeneration and repair. https://www.jove.com/v/65819 340 2023-11-17T21:10:00+00:00 JoVE no https://visualize.jove.com/2748081-more-assured-in-the-bag-placement-of-c-loop-posterior-chamber-intraocular-lenses monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14619.jpg Coagulation Colloidal solids are solid particles suspended in solution. They are usually negatively charged, attracting a compact primary layer of positively charged ions, which attract more counterions to form an electrical double layer. Electrostatic repulsion between the charged double layers prevents the particles from colliding, stabilizing the colloids. These solids are often undesirable because they can contain toxins that are difficult to remove. Coagulation is a technique that helps aggregate and... https://app.jove.com/v/14619 66 1500 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15256.jpg Coagulation The coagulation phase is a critical part of the body's process to prevent blood loss following injury to blood vessels. It involves chemical reactions that form a clot to seal the injured area. The clotting process begins shortly after injury, within 15-20 seconds for severe damage and 1-2 minutes for minor injuries. During the coagulation phase, clotting factors, or procoagulants, play a vital role in initiating and progressing the coagulation cascade. This cascade is a series of reactions... https://app.jove.com/v/15256 69 8400 JoVE no https://visualize.jove.com/2801249-future-applications-of-magic-lite-technology monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12979.jpg Issues And Trends In Healthcare Delivery System The issues and trends in healthcare delivery are constantly changing. The COVID-19 pandemic is one recent issue that wreaked havoc on healthcare systems, causing a shortage of healthcare workers, high demand for medicines and supplies, and increased medical expenditure due to a lack of insurance. Other issues include rising healthcare costs and care fragmentation. Cost Containment Payment for healthcare services has historically promoted adoption of costly and often unnecessary or inefficient... https://www.jove.com/v/12979 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13764.jpg Magnetism Magnets are commonly found in everyday objects, such as toys, hangers, elevators, doorbells, and computer devices. Experimentation on these magnets shows that all magnets have two poles: one is labeled north (N) and the other south (S). Magnetic poles repel if they are alike and attract if unlike. Moreover, both poles of a magnet attract unmagnetized pieces of iron. An individual magnetic pole cannot be isolated. No matter how small, every piece of a magnet contains a north pole and a south... https://www.jove.com/v/13764 90 JoVE no https://cloudfront.jove.com/files/ftp_upload/19466/19466_article_thumb_19466.jpg Microorganisms in Medicine and Therapeutics Microorganisms play a fundamental role in vaccine development, gene therapy, and therapeutic production. Their biological properties are harnessed to advance medicine and public health. Beyond immunization, microorganisms contribute to gut health, antibiotic synthesis, and genetic disease treatment.Live Attenuated and Inactivated VaccinesLive attenuated vaccines, such as the measles, mumps, and rubella (MMR) vaccine, utilize weakened forms of pathogens to closely resemble natural infections. https://www.jove.com/v/19466 89 2026-02-11T18:41:05+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19922/19922_article_thumb_19922.jpg Magical Thinking Magical thinking encompasses the belief in assumptions that defy logical reasoning yet appear intuitively convincing. It is a common psychological phenomenon that persists across various cultural and individual contexts. While these assumptions contradict empirical evidence and scientific laws, they often serve meaningful psychological roles in promoting emotional resilience and a sense of control, especially under stress or uncertainty.Thought-Action Fusion and the Law of SimilarityA key... https://www.jove.com/v/19922 89 2025-09-18T17:24:17+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53728.jpg Laser-induced Forward Transfer of Ag Nanopaste We demonstrate the use of the Laser-induced forward transfer technique (LIFT) for the printing of high-viscosity Ag paste. This technique offers a simple, low temperature, robust process for non-lithographically printing microscale 2D and 3D structures. https://www.jove.com/v/53728 487 2016-03-31T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61334.jpg Demonstration of Spin-Multiplexed and Direction-Multiplexed All-Dielectric Visible Metaholograms We present a protocol for fabrication of spin- and direction-multiplexed visible metaholograms, then conduct an optical experiment to verify their function. These metaholograms can easily visualize encoded information, so they can be used for projective volumetric display and information encryption. https://www.jove.com/v/61334 528 2020-09-25T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68126.jpg Laser Micromachining for Polymer Surface Topography Design A method for imposing surface topography of light-absorbing composite polymer materials, particularly magnetoactive elastomers (MAEs), by using laser micromachining is presented. This method enables large flexibility in topographical designs and rapid prototyping. An example of structuring MAE surfaces, characterization, and their response to the external magnetic field is demonstrated. https://www.jove.com/v/68126 349 2025-09-19T19:55:00+00:00 JoVE no https://visualize.jove.com/2809672-automating-the-recording-and-improving-the-presentation-of-the-anesthesia-record monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13540.jpg Data Reporting and Recording Reporting and recording are crucial in data documentation. The timely, thorough, and accurate documentation of facts is essential when recording patient data. Failure to record findings during an assessment or interpretation of a problem will result in loss of information and make the patient document unreliable. The reader is left with general impressions if the information is not specific. A recording is documenting data of the individual's health information in a traceable, secure, and... https://www.jove.com/v/13540 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14100.jpg Introduction to Documentation and Reporting Documentation is the systematic process of formally recording, maintaining, and communicating information. Nursing documentation records essential information and details regarding a patient's care and treatment in written or electronic form. It is a critical aspect of nursing practice that involves documenting assessments, interventions, outcomes, and other relevant details about a patient's health status. Documentation maps the patient's health journey by creating a comprehensive and precise... https://www.jove.com/v/14100 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14106.jpg Guidelines for Nursing Documentation II Effective documentation is an integral part of nursing practice. Here are some essential guidelines to follow when documenting patient care: Timely documentation is crucial to ensure continuity of care for patients. Any delays in recording or reporting medical information can result in medical errors and even adverse patient outcomes. From medication administration to diagnostic test results, every detail must be accurately and promptly documented to provide the best possible care for patients.<br... https://www.jove.com/v/14106 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14108.jpg Types of Records II: Educational and Administrative Records Maintaining nurses' educational and administrative records in healthcare settings, including hospitals and nursing schools, is paramount. Here's a breakdown of the types of academic records mentioned: • Qualification Documentation: Educational records are crucial in assessing nurses' qualifications. These include degrees, certifications, and specialized training. They play a vital role in ensuring nurses are suitably qualified. • Skill and Ability Assessment: Nurses' records of educational... https://www.jove.com/v/14108 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14116.jpg Guidelines and Strategies for Safe Computer Charting The guidelines and strategies provided by the American Nurses Association (ANA) and the Canadian Nurses Association (CNA) offer essential principles for ensuring safe and secure computer charting systems in healthcare settings. Let's break down each recommendation: Maintain Confidentiality and Security: • Never share computer signatures or passwords with anyone, including colleagues or float nurses, to prevent unauthorized access to patient records. • Always log out of computer terminals... https://www.jove.com/v/14116 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14123.jpg Legal Guidelines for Documentation The legal guidelines for nursing documentation are essential for ensuring accurate, professional, and ethical recording of patient care. The guidelines are discussed here: • Avoid Retaliatory or Critical Comments: Documenting disrespectful comments about patients or other professionals can reflect poorly on the quality of care and the professionalism of the healthcare environment. This kind of documentation can be interpreted as unprofessional and may have legal implications. • Include Date,... https://www.jove.com/v/14123 66 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56881.jpg Recording Brain Electromagnetic Activity During the Administration of the Gaseous Anesthetic Agents Xenon and Nitrous Oxide in Healthy Volunteers Simultaneous magnetoencephalography and electroencephalography provides a useful tool to search for common and distinct macro-scale mechanisms of reductions in consciousness induced by different anesthetics. This paper illustrates the empirical methods underlying the recording of such data from healthy humans during N-Methyl-D-Aspartate-(NMDA)-receptor-antagonist-based anesthesia during inhalation of nitrous oxide and xenon. https://www.jove.com/v/56881 892 2018-01-13T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61311.jpg Use of an Integrated Low-Flow Anesthetic Vaporizer, Ventilator, and Physiological Monitoring System for Rodents Here, we present a protocol to safely and effectively administer anesthetic gas to mice using a digital, low flow anesthesia system with integrated ventilator and physiological monitoring modules. https://www.jove.com/v/61311 417 2020-07-09T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64417.jpg Reduced Procedure Time and Variability with Active Esophageal Cooling During Radiofrequency Ablation for Atrial Fibrillation This study utilized advanced informatics techniques to compare procedure duration in patients undergoing radiofrequency atrial ablation treated with active esophageal cooling to those treated with traditional luminal esophageal temperature monitoring. Contextual inquiry, workflow analysis, and data mapping were utilized. The findings demonstrated reduced procedure time and variability with active cooling. https://www.jove.com/v/64417 298 2022-08-25T22:00:00+00:00 JoVE no https://visualize.jove.com/2815600-urinary-excretion-of-catecholamines-by-the-transplanted-kidney monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14413.jpg Drug Elimination by Renal Route: Tubular Secretion Once the process of glomerular filtration is completed, blood carrying unfiltered drug molecules traverses through efferent arterioles and makes its way into the peritubular capillaries in the proximal tubule. A variety of carriers play a pivotal role in actively secreting drugs from these peritubular capillaries into the tubular fluid. The organic anion transporter transfers acidic drugs, against an electrochemical gradient, from the peritubular capillaries into the renal tubule cells and... https://www.jove.com/v/14413 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16545.jpg Renal Drug Excretion: Overview As primary excretory organs, the kidneys maintain homeostasis by removing waste substances from the bloodstream. They comprise over a million units called nephrons, which serve as the kidney's functional units. A nephron consists of two primary structures: the renal corpuscle and the renal tubule. The renal corpuscle contains the glomerulus, a network of capillaries where the first step of renal excretion, glomerular filtration, occurs. Blood pressure forces water, ions, and small molecules out... https://www.jove.com/v/16545 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16547.jpg Renal Drug Excretion: Tubular Reabsorption Tubular reabsorption, a process occurring post-glomerular filtration of drugs in the renal tubule, is a critical determinant of drug half-life. During the process of renal excretion, as the glomerular filtrate progresses to the distal convoluted tubule (DCT), drugs that are highly permeable, lipophilic, and nonionized undergo passive reabsorption from the tubular fluid into the surrounding peritubular capillaries. This reabsorption process restricts their elimination through the kidneys. This... https://www.jove.com/v/16547 85 JoVE no https://cloudfront.jove.com/files/ftp_upload/18456/18456_article_thumb_18456.jpg Physiology of the Genitourinary System II: Tubular Reabsorption and Secretion The kidneys maintain homeostasis through filtration, reabsorption, and secretion. Tubular reabsorption and secretion are crucial in forming urine and regulating electrolytes, water balance, and waste elimination.Tubular Reabsorption and Secretion ProcessesTubular reabsorption is the process that reclaims essential substances such as electrolytes, glucose, amino acids, and water from the glomerular filtrate back into the bloodstream. This is achieved through passive and active transport... https://www.jove.com/v/18456 82 2025-06-19T09:22:28+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18484/18484_article_thumb_18484.jpg Kidney Transplant II: Surgical Procedure Preoperative ManagementThe primary goals of preoperative management in kidney transplantation are to optimize the patient’s metabolic state and prepare them for surgery through diet adjustments, necessary dialysis, and tailored medical treatment. This phase also involves comprehensive infection screening and patient education about the surgical procedure and postoperative care to improve outcomes and adherence.Medical ManagementA comprehensive evaluation is required for both the living donor... https://www.jove.com/v/18484 86 2025-06-19T09:28:34+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18485/18485_article_thumb_18485.jpg Kidney Transplant III: Nursing Management Postoperative Nursing Management for Kidney Transplant PatientsPostoperative nursing management care includes monitoring the surgical site, encouraging early movement, and promoting lung health through breathing exercises. Nurses also administer prescribed medications like H2-blockers, such as famotidine, or proton pump inhibitors, like omeprazole, to help prevent gastrointestinal ulcers and bleeding. Fungal infections in the mouth and bladder can result from immunosuppressive and antibiotic... https://www.jove.com/v/18485 76 2025-06-19T09:28:44+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52163.jpg Mouse Kidney Transplantation: Models of Allograft Rejection Here, we present a protocol to study the immunology of rejection. The surgical model presented reports a short operating time and a concise technique. Depending on the donor-recipient strain combination, the transplanted kidney may develop acute cellular rejection or chronic allograft damage, defined by interstitial fibrosis and tubular atrophy. https://www.jove.com/v/52163 975 2014-10-11T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54712.jpg The Mouse Isolated Perfused Kidney Technique The mouse isolated perfused kidney (MIPK) is a technique for keeping a mouse kidney under ex vivo conditions perfused and functional for 1 hr. The buffers and surgical technique are described in detail. https://www.jove.com/v/54712 499 2016-11-17T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59403.jpg Orthotopic Rat Kidney Transplantation: A Novel and Simplified Surgical Approach The purpose of this manuscript and protocol is to explain and demonstrate in detail the surgical procedure of orthotopic kidney transplantation in rats. This method is simplified to achieve the correct perfusion of the donor kidney and shorten the reperfusion time by using the venous and ureteral cuff anastomosis technique. https://www.jove.com/v/59403 555 2019-05-07T14:00:00+00:00 JoVE no https://visualize.jove.com/2816859-aminoglycoside-ototoxicity-in-cystic-fibrosis-evaluation-by-high-frequency-audiometry monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15368.jpg Cystic Fibrosis: Management Cystic fibrosis (CF) is an autosomal recessive disorder that predominantly affects individuals of Northern European descent, occurring at a rate of 1 in 3500. It is caused by a genetic mutation in a gene on chromosome 7, most commonly the ΔF508 mutation, that codes for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. This results in thicker mucus secretions and obstruction pathologies in multiple organs, including the lungs and sinuses. Sinus disease and chronic sinusitis... https://www.jove.com/v/15368 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53264.jpg Neuro-rehabilitation Approach for Sudden Sensorineural Hearing Loss This article reports the development of a neuro-rehabilitation approach, "constraint-induced sound therapy (CIST)" for sudden sensorineural hearing loss. The aim of CIST is to prevent maladaptive cortical reorganization by using an enriched acoustic environment. CIST represents a safe, easy, inexpensive, and effective approach to treat sudden sensorineural hearing loss. https://www.jove.com/v/53264 584 2016-01-26T01:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56564.jpg Trans-Tympanic Drug Delivery for the Treatment of Ototoxicity We present a technique for localized administration of drugs through the trans-tympanic route into the cochlea. Drug delivery through this route would not interfere with the anti-cancer efficacy of the chemotherapeutic drugs such as cisplatin. https://www.jove.com/v/56564 592 2018-03-16T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58073.jpg Cochlear Implant Surgery and Electrically-evoked Auditory Brainstem Response Recordings in C57BL/6 Mice Animal models of cochlear implants can advance knowledge of the technological bases of treating permanent sensorineural hearing loss with electrical stimulation. This study presents a surgical protocol for acute deafening and cochlear implantation of an electrode array in mice as well as the functional assessment with auditory brainstem response. https://www.jove.com/v/58073 546 2019-01-09T21:00:00+00:00 JoVE no https://visualize.jove.com/2826328-induction-of-cylindrical-confronting-cisternae-aids-inclusions-in-daudi-lymphoblastoid-cells-by-recombinant-alpha-interferon monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15348.jpg B Cell Activation and Differentiation The adaptive immune response, a sophisticated defense mechanism, relies on the activation and differentiation of B lymphocytes, or B cells. These processes enable our bodies to mount a tailored response against specific pathogens such as bacteria, free virus particles, toxins, and parasites. When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with... https://www.jove.com/v/15348 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15354.jpg Defense Against Bacterial Pathogens The human immune system is a complex network of cells, tissues, and organs that work together to defend the body against bacterial infections. It consists of various immune cells, each playing a specific role in the defense mechanism. Phagocytes Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol... https://www.jove.com/v/15354 91 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59174.jpg Induction of Drug-Induced, Autoimmune Hepatitis in BALB/c Mice for the Study of Its Pathogenic Mechanisms We describe an in vivo immunization, translational hepatitis model in BALB/c mice that can be utilized to study the pathogenesis of drug-induced autoimmune hepatitis including sex differences seen in this disease. We will describe how this model demonstrates reproducible analyses using in vivo and in vitro experimental techniques. https://www.jove.com/v/59174 696 2020-05-29T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60585.jpg In Vivo Augmentation of Gut-Homing Regulatory T Cell Induction Here we present a protocol for in vivo augmentation of gut-homing regulatory T cell induction. In this protocol, dendritic cells are engineered to locally produce high concentrations of the active vitamin D (1,25-dihydroxyvitamin D or 1,25[OH]2D) and the active vitamin A (retinoic acid or RA) de novo. https://www.jove.com/v/60585 482 2020-01-22T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61009.jpg Induction of Leptomeningeal Cells Modification Via Intracisternal Injection We describe an intracisternal injection that employs a needle bent at the tip that can be stabilized to the skull, thus eliminating the risk of damage to the underlying parenchyma. The approach can be used for genetic fate mapping and manipulations of leptomeningeal cells and for tracking cerebrospinal fluid movement. https://www.jove.com/v/61009 355 2020-05-07T21:30:00+00:00 JoVE no https://visualize.jove.com/2887574-the-gene-for-ornithine-decarboxylase-is-co-amplified-in-hydroxyurea-resistant-hamster-cells monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13483.jpg iPS Cell Differentiation The ability of induced pluripotent stem cells or iPSCs to differentiate into most body cell types has stimulated repair and regenerative medicine research over the past few decades. iPSC-derived blood cells, hepatocytes, beta islet cells, cardiomyocytes, neurons, and other cell types can repair injuries or regenerate damaged tissue in diseases such as diabetes and neurodegenerative disorders. iPSCs have been successfully used to treat age-related macular degeneration (AMD), a form of blindness. https://www.jove.com/v/13483 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13485.jpg EPS and iPS Cells in Disease Research Embryonic and induced pluripotent stem cells are excellent models for disease research because of their ability to self-renew and differentiate into most cell types. Somatic cells from a patient are isolated and reprogrammed into induced pluripotent stem cells or iPSCs. These iPSCs are later differentiated into the desired cell type, which mirrors the diseased cell of the patient. In this way, disease models have been created for investigating diseases such as Down syndrome, type I diabetes,... https://www.jove.com/v/13485 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55263.jpg Targeted in Situ Mutagenesis of Histone Genes in Budding Yeast A strategy for generating mutations in histone genes at their endogenous location in Saccharomyces cerevisiae is presented. https://www.jove.com/v/55263 528 2017-01-26T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56430.jpg Overexpression and Purification of Human Cis -prenyltransferase in Escherichia coli A simple protocol for overexpression and purification of codon-optimized, human cis-prenyltransferase, under non-denaturing conditions, from Escherichia coli, is described, along with an enzymatic activity assay. This protocol can be generalized for production of other cis- prenyltransferase proteins in quantity and quality suitable for mechanistic studies. https://www.jove.com/v/56430 455 2017-08-03T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58419.jpg Inducible and Reversible Dominant-negative (DN) Protein Inhibition Here we present a protocol to develop a dominant-negative inducible system, in which any protein can be conditionally inactivated by reversibly overexpressing a dominant-negative mutant version of it. https://www.jove.com/v/58419 515 2019-01-07T22:00:00+00:00 JoVE no https://visualize.jove.com/2889666-transcription-of-il-2-receptor-gene-is-stimulated-by-atl-derived-factor-produced-by-htlv-i-t-cell-lines monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2307.jpg Retroviral Transduction of T-cell Receptors in Mouse T-cells We present a protocol to produce antigen-specific mouse T-cells using retroviral... https://www.jove.com/v/2307 614 2010-10-23T00:35:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12561.jpg General Transcription Factors Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of... https://www.jove.com/v/12561 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15345.jpg T Cell Activation and Clonal Selection T cells are integral to our adaptive immune system, recognizing and effectively responding to foreign antigens. T cell activation and clonal selection are pivotal in orchestrating this immune response. This article elucidates these mechanisms, detailing the roles of cluster of differentiation (CD) markers, major histocompatibility complex (MHC) molecules, costimulatory signals, and the process of clonal selection. Naive T cells that have not yet encountered an antigen express two primary CD... https://www.jove.com/v/15345 82 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54697.jpg Generating De Novo Antigen-specific Human T Cell Receptors by Retroviral Transduction of Centric Hemichain Herein we describe a novel method to generate antigen-specific T cell receptors (TCRs) by pairing the TCRα or TCRβ of an existing TCR, possessing the antigen-specificity of interest, with complementary hemichain of the peripheral T cell receptor repertoire. The de novo generated TCRs retain antigen-specificity with varying affinity. https://www.jove.com/v/54697 528 2016-10-25T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54698.jpg Retroviral Transduction of Helper T Cells as a Genetic Approach to Study Mechanisms Controlling their Differentiation and Function Many experimental systems have been utilized to understand the mechanisms regulating T cell development and function in an immune response. Here a genetic approach using retroviral transduction is described, which is economic, time efficient, and most importantly, highly informative in identifying regulatory pathways. https://www.jove.com/v/54698 710 2016-11-04T22:00:00+00:00 JoVE no https://visualize.jove.com/2974116-evaluation-of-water-electrolyte-metabolism-in-patients-with-upper-gi-tract-cancer-the-dynamic-status-of-secretion-of-alpha-hanp-levels monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16408.jpg Assessment of the Gastrointestinal System I: Subjective Data Assessing the gastrointestinal (GI) system is a complex process that begins with collecting subjective data. This data, collected through patient interviews, provides crucial insights into the patient's health history, perception patterns, and lifestyle habits, all contributing significantly to GI health. Health History The initial step in assessing the GI system is obtaining a comprehensive health history. This includes inquiring about the patient's history or presence of problems related to... https://www.jove.com/v/16408 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16445.jpg Serum Laboratory Studies, Stool Test, Breath Test Gastrointestinal (GI) diagnostic studies are pivotal in confirming, ruling out, diagnosing, or staging various diseases, including cancers. Following diagnosis, allocating time for discussions with the patient and providing informational resources is crucial. Diagnostic assessments of the GI tract often occur in outpatient settings like endoscopy suites or GI labs. Preparation for these tests may include dietary restrictions, fasting, liquid bowel preparations, laxatives, enemas, and the... https://www.jove.com/v/16445 90 JoVE no https://cloudfront.jove.com/files/ftp_upload/17982/17982_article_thumb_17982.jpg Aneurysm IV: Nursing Management Vigilant monitoring for aneurysm rupture is essential for patients undergoing aortic surgery.Preoperative Nursing ManagementContinuously monitor the patient for manifestations of aneurysm rupture, such as pallor, weakness, tachycardia, hypotension, abdominal, back, groin, or periumbilical pain, changes in consciousness, and a pulsating abdominal mass. Regularly assess the patient's peripheral pulses.Instruct the patient to consume a clear liquid diet the day before surgery and administer... https://www.jove.com/v/17982 82 2025-06-19T16:19:35+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18459/18459_article_thumb_18459.jpg Nursing Assessment of the Genitourinary System II: Inspection and Palpation The nursing assessment of the genitourinary (GU) system involves a systematic inspection and palpation to identify abnormalities in the kidneys, bladder, and surrounding structures.InspectionMouth: Inspect for signs of kidney dysfunction, such as stomatitis (inflammation of the mouth) and ammonia breath, which may occur in advanced kidney disease due to the buildup of urea, breaking down into ammonia.Skin: Check for pallor, which could indicate anemia caused by kidney disease. Look for... https://www.jove.com/v/18459 86 2025-06-20T23:30:53+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18502/18502_article_thumb_18502.jpg Acute Kidney Injury VI: Nursing Management Acute Kidney Injury (AKI) results in an inability to maintain fluid, electrolyte, and acid-base balance. Effective nursing management is critical in improving patient outcomes and includes comprehensive patient assessment and targeted interventions.Comprehensive Patient AssessmentA detailed history collection is essential, focusing on any recent infections, nephrotoxic medication use, or chronic conditions such as hypertension and diabetes that may contribute to AKI. During the physical... https://www.jove.com/v/18502 82 2025-06-19T16:32:16+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18507/18507_article_thumb_18507.jpg Chronic Kidney Disease IV: Nursing Management Nursing management is essential for preventing complications, maintaining stability, and improving patients' quality of life in chronic kidney disease (CKD). By using a structured approach, nurses help slow CKD progression and support effective patient care​.1. Comprehensive patient assessmentEffective management begins with nurses reviewing the patient’s medical history, and identifying key risk factors like diabetes, hypertension, and nephrotoxic drug use. Nurses assess signs of fluid... https://www.jove.com/v/18507 78 2025-06-19T16:33:10+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61641.jpg Simultaneous Laryngopharyngeal and Conventional Esophageal pH Monitoring Laryngopharyngeal pH monitoring has been specifically designed to measure acid exposure above the upper esophageal sphincter and complements diagnostic evaluation in patients that present with mainly extraesophageal reflux symptoms. Patients with suspected laryngopharyngeal reflux (LPR) were evaluated using distal esophageal and laryngopharyngeal pH testing simultaneously. https://www.jove.com/v/61641 406 2020-12-14T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62864.jpg Construction of a Wireless-Enabled Endoscopically Implantable Sensor for pH Monitoring with Zero-Bias Schottky Diode-based Receiver The manuscript presents a miniature implantable pH sensor with ASK modulated wireless output together with a fully passive receiver circuit based on zero-bias Schottky diodes. This solution can be used as a basis in the development of in vivo calibrated electrostimulation therapy devices and for ambulatory pH monitoring. https://www.jove.com/v/62864 505 2021-08-27T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64683.jpg Evaluation of Hydration Status by Bioelectrical Impedance Vector Analysis in Patients with Ischemic Heart Disease Undergoing Exercise Stress Test Hydration status imbalances can have a short-term effect on direct and indirect determinants of oxygen uptake and pulse, and morbidity and mortality prognostic factors in ischemic heart disease. This protocol describes the technique for assessment of hydration status through bioelectrical impedance vector analysis and cardiopulmonary response during exercise stress test. https://www.jove.com/v/64683 621 2023-09-22T20:50:00+00:00 JoVE no https://visualize.jove.com/2993905-primary-structure-of-the-alpha-subunit-of-torpedo-californica-na-katpase-deduced-from-cdna-sequence monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11901.jpg ATP Synthase: Mechanism In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP... https://www.jove.com/v/11901 108 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11904.jpg ATP Synthase: Structure ATP synthase or ATPase is among the most conserved proteins found in bacteria, mammals, and plants. This enzyme can catalyze a forward reaction in response to the electrochemical gradient, producing ATP from ADP and inorganic phosphate. ATP synthase can also work in a reverse direction by hydrolyzing ATP and generating an electrochemical gradient. Different forms of ATP synthases have evolved special features to meet the specific demands of the cell. Based on their specific feature, ATP... https://www.jove.com/v/11904 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11905.jpg The ADP/ATP Carrier Protein ADP/ATP carrier or AAC protein is the most abundant carrier protein in the inner mitochondrial membrane. It transports large quantities of ADP and ATP, equivalent to the average human body weight, every day. Among other transporters, ACC protein is one of the best-studied members of the mitochondrial carrier protein family. The ADP/ATP carrier protein comprises two transmembrane helices connected to a loop and a single alpha-helix on the matrix side. It switches between two conformational... https://www.jove.com/v/11905 102 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12129.jpg Tail-anchoring of Proteins in the ER Membrane Tail-anchored, or TA, proteins are estimated to make up to 3-5% of membrane proteins found in the eukaryotic cell. Such proteins have a single transmembrane domain located approximately 30 amino acid residues upstream from the C-terminal end. As a result, the signal recognition particle (SRP) cannot guide a TA protein to the ER membrane for cotranslational insertion. Hence, they are integrated into the ER membrane post-translationally using their C-terminal end as the anchor. TA proteins... https://www.jove.com/v/12129 105 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12217.jpg ATP Driven Pumps II: P-type Pumps The P-type pumps are a large family of integral membrane transporter ATPases. They are divided into five major types based on substrate specificity, from I to V. A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly... https://www.jove.com/v/12217 94 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12221.jpg Allosteric Proteins-ATCase Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor. Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,... https://www.jove.com/v/12221 79 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50201.jpg Measuring Cation Transport by Na,K- and H,K-ATPase in Xenopus Oocytes by Atomic Absorption Spectrophotometry: An Alternative to Radioisotope Assays We describe a method to quantify the activity of K+-countertransporting P-type ATPases by heterologous expression of the enzymes in Xenopus oocytes and measuring Rb+ or Li+ uptake into individual cells by atomic absorption spectrophotometry. The method is a sensitive and safe alternative to radioisotope flux experiments facilitating complex kinetic studies. https://www.jove.com/v/50201 768 2013-02-19T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51228.jpg Visualization of ATP Synthase Dimers in Mitochondria by Electron Cryo-tomography We present a protocol of how to collect and process electron cryo-tomograms of whole mitochondria. The technique provides detailed insights into the structure, function, and organization of large membrane protein complexes in native biological membranes. https://www.jove.com/v/51228 639 2014-09-14T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62770.jpg Chemical Modification of the Tryptophan Residue in a Recombinant Ca 2+ -ATPase N-domain for Studying Tryptophan-ANS FRET ANS binds to the Ca2+-ATPase recombinant N-domain. Fluorescence spectra display a FRET-like pattern upon excitation at a wavelength of 295 nm. NBS-mediated chemical modification of Trp quenches the fluorescence of the N-domain, which leads to the absence of energy transfer (FRET) between the Trp residue and ANS. https://www.jove.com/v/62770 727 2021-10-09T20:00:00+00:00 JoVE no https://visualize.jove.com/3026863-studies-into-disturbing-receptor-memory-in-a-unicellular-tetrahymena-model-system-changes-in-the-imprinting-potential-on-exposure-to-combinations-of-related-and-unrelated-hormones monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10876.jpg Intracellular Hormone Receptors Lipid-soluble hormones diffuse across the plasma and nuclear membrane of target cells to bind to their specific intracellular receptors. These receptors act as transcription factors that regulate gene expression and protein synthesis in the target cell Based on their mode of action, intracellular hormone receptors are classified as Type I or Type II receptors. Type I receptors, including steroid hormone receptors such as the androgen receptor, are present in the cytoplasm. Hormone binding... https://www.jove.com/v/10876 68 2025-10-23T18:46:58+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11619.jpg Genomic Imprinting and Inheritance Diploid organisms inherit genetic material through chromosomes from both parents. Copies of the same gene are known as alleles. In most cases, both alleles are simultaneously expressed and allow various cellular processes to function optimally. If one of the alleles is missing or mutated, the expression of the other allele can compensate; however, this is not true for all genes. The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as... https://www.jove.com/v/11619 150 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50107.jpg Drosophila Adult Olfactory Shock Learning The method to measure adult Drosophila associative memory is described. The assay is based on the ability of the fly to associate an odor presented with a negative reinforcer (electric shock) and then recall this information at a later time, allowing memory to be measured. https://www.jove.com/v/50107 588 2014-08-08T02:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64137.jpg Aversive Associative Learning and Memory Formation by Pairing Two Chemicals in Caenorhabditis elegans We have previously developed protocols for Caenorhabditis elegans to form short- and long-term associative memories by massed and spaced training, respectively. Here, detailed protocols are described for the conditioning of C. elegans by pairing 1-propanol and hydrochloric acid as conditioned and unconditioned stimuli, respectively, to form aversive associative memory. https://www.jove.com/v/64137 437 2022-06-23T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68332.jpg In Vivo Imaging of Neural Activity in Unanesthetized Drosophila Adult Flies A significant barrier to studying cellular activity during cognitive processes like learning and memory is the use of anesthetics for in vivo imaging preparation. Anesthesia impairs short-term memory and cognition in multiple models, including Drosophila. This study presents a unique method for preparing adult Drosophila for in vivo imaging without anesthesia. https://www.jove.com/v/68332 555 2025-06-20T20:30:00+00:00 JoVE no https://visualize.jove.com/3213055-signal-detection-by-analogdigital-conversion-using-personal-computers-iii-examples-from-general-practice-and-organizational-aspects monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15076.jpg Operational Amplifiers The operational amplifier, often referred to as an op-amp, is a multifaceted building block of a circuit. This electronic component functions like a voltage-controlled voltage source and can also be used to create a voltage- or current-controlled current source. The design of an operational amplifier enables it to execute mathematical operations when external components like resistors and capacitors are linked to its terminals. An op-amp has the capacity to sum signals, amplify a signal,... https://www.jove.com/v/15076 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15172.jpg Design Example: Vintage Mixing Console A sound engineer at a music company recently encountered a problem. The output from their newly acquired studio's vintage mixing console was too low for the requirements of modern recording equipment. To rectify this situation, the engineer decided to design an audio pre-amplifier using an operational amplifier (op-amp) to boost the signal level. The specifications for the pre-amplifier were clear. It needed to amplify the audio signal by a factor of 10, have an input impedance above 10... https://www.jove.com/v/15172 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15177.jpg Design Example The innovation of touch-tone telephony revolutionized the telecommunications industry by replacing the traditional rotary dial with a dual-tone multi-frequency (DTMF) signaling system. This system uses a matrix-style keypad with buttons arranged in four rows and three columns, creating 12 distinct signals each assigned to a pair of frequencies. Each button press results in a simultaneous generation of two sinusoidal tones – one from a low-frequency group (697 to 941 Hz) and one from a... https://www.jove.com/v/15177 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16029.jpg Signal and System A signal x(t) is a set of data or a time function representing a variable of interest. Signals typically convey information about a phenomenon, such as atmospheric temperature, humidity, human voice, television images, a dog's bark, or birdsongs. More generally, a signal can be a function of more than one independent variable. For instance, images depend on horizontal and vertical positions and can be regarded as two-dimensional signals. However, this text will focus on one-dimensional signals... https://www.jove.com/v/16029 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16077.jpg Sampling Continuous Time Signal In signal processing, a continuous-time signal can be sampled using an impulse-train sampling technique, followed by the zero-order hold method. Impulse-train sampling involves the use of a periodic impulse train, which consists of a series of delta functions spaced at regular intervals determined by the sampling period. When a continuous-time signal is multiplied by this impulse train, it generates impulses with amplitudes corresponding to the signal's values at the sampling points. In the... https://www.jove.com/v/16077 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16079.jpg Aliasing Accurate signal sampling and reconstruction are crucial in various signal-processing applications. A time-domain signal's spectrum can be revealed using its Fourier transform. When this signal is sampled at a specific frequency, it results in multiple scaled replicas of the original spectrum in the frequency domain. The spacing of these replicas is determined by the sampling frequency. If the sampling frequency is below the Nyquist rate, these replicas overlap, preventing the original signal... https://www.jove.com/v/16079 78 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61989.jpg Studying Cavitation Enhanced Therapy The presented experimental protocol can be used to perform real time measurements of cavitation activity in a cell culture device with the aim of enabling investigation of the conditions required for successful drug delivery and/or other bioeffects. https://www.jove.com/v/61989 456 2021-04-09T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68390.jpg High-precision Electromagnetic Flowmeter with Empty Pipe Detection via Complex Programmable Logic Device-based Waveform Recognition This study improves electromagnetic flowmeter accuracy by optimizing excitation waveforms, applying multi-stage filtering, and using Complex Programmable Logic Device (CPLD)-based rectification. A novel waveform-based empty pipe detection method enhances reliability. Experiments show 0.1% accuracy within 0.1-15 m/s, validating industrial applicability. https://www.jove.com/v/68390 311 2025-06-27T20:05:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68767.jpg TD-DFT Guided Advanced E-Eye Sensing Technique for On-site Quantification of Fe, Cr, F, and As in the Environmental, Biological, and Food Samples This work has discussed the protocol for designing and developing an E-Eye-Enable POCT device to detect Fe, Cr, As, and F in environmental samples, biological samples, and food and beverages. Nearly 2000 samples have been tested, and the results accord with the gold-standard technique. https://www.jove.com/v/68767 591 2025-09-19T20:50:00+00:00 JoVE no https://visualize.jove.com/3289625-characteristics-of-learning-in-ontogeny monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17805.jpg Introduction to Learning Learning is the process of acquiring knowledge or skills through practice or experience, leading to long-lasting behavioral changes. This acquisition occurs through interaction with the environment and requires practice or experience. For instance, mastering a skill such as surfing requires considerable practice and experience, highlighting the essential role of repeated interactions with the environment in learning. In contrast to learned behaviors, unlearned behaviors such as crying, sexual... https://www.jove.com/v/17805 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17822.jpg Cognitive Learning Cognitive learning is based on purposive behavior, incidental learning, and insight learning. E. C. Tolman's theory of purposive behavior emphasizes that much behavior is goal-directed. He argued that to understand behavior, we must look at the entire sequence of actions leading to a goal. For instance, high school students study hard, not just due to past reinforcement but also to achieve the goal of getting into a good college. Tolman introduced the idea that behavior is influenced by... https://www.jove.com/v/17822 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17823.jpg Purposive Learning E. C. Tolman emphasized the purposiveness of behavior — the idea that much of our behavior is goal-directed. For instance, employees who aim for a promotion work diligently to meet their targets. Tolman argued that when classical conditioning and operant conditioning occur, the organism acquires certain expectations. In classical conditioning, a child might fear a dog because they expect it to bite. In operant conditioning, a person might consistently work overtime because they expect a bonus... https://www.jove.com/v/17823 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17824.jpg Observational Learning Albert Bandura's observational learning, also known as imitation or modeling, occurs when a person observes and imitates another's behavior. It is a quicker process than operant conditioning. A well-known example is the Bobo doll study, where children who saw an adult acting aggressively towards the doll were more likely to act aggressively when left alone, compared to those who observed a nonaggressive adult. Many psychologists view observational learning as a form of latent learning because... https://www.jove.com/v/17824 72 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18553.jpg Piaget's Theory of Cognitive Development from Childhood into Adulthood Jean Piaget's theory of cognitive development emphasizes the role of thinking in a child's learning process, suggesting that children are naturally curious about their environment. His approach to development is discontinuous, proposing that cognitive abilities progress through distinct stages, each with unique characteristics. Central to Piaget's theory is schemata—mental structures that allow individuals to understand and interpret the world. Schemata: Building Blocks of Knowledge Schemata... https://www.jove.com/v/18553 85 2025-08-13T20:50:22+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18560.jpg The Nativist Approach The nativist approach to infant cognitive development proposes that infants are born with inherent knowledge structures that allow them to interpret the world almost immediately. This perspective contrasts with earlier developmental theories, such as those proposed by Jean Piaget, which emphasized a more gradual acquisition of cognitive abilities through interaction with the environment. One key concept in this approach is object permanence — the understanding that objects continue to exist... https://www.jove.com/v/18560 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51283.jpg Recording Single Neurons' Action Potentials from Freely Moving Pigeons Across Three Stages of Learning Learning new stimulus-response associations engages a wide range of neural processes which are ultimately reflected in changing spike output of individual neurons. Here we describe a behavioral protocol allowing for the continuous registration of single-neuron activity while animals acquire, extinguish, and reacquire a conditioned response within a single experimental session. https://www.jove.com/v/51283 680 2014-06-02T20:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52841.jpg Quantifying Learning in Young Infants: Tracking Leg Actions During a Discovery-learning Task A method is described in which 3-4 month old infants learn a task by discovery and their leg movements are captured to quantify the learning process. https://www.jove.com/v/52841 678 2015-06-01T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61474.jpg Measuring Statistical Learning Across Modalities and Domains in School-Aged Children Via an Online Platform and Neuroimaging Techniques Presented here is a protocol introducing a set of child-friendly statistical learning tasks geared towards examining children’s learning of temporal statistical patterns across domains and sensory modalities. The developed tasks collect behavioral data using the web-based platform and task-based functional magnetic resonance imaging (fMRI) data for examining neural engagement during statistical learning. https://www.jove.com/v/61474 485 2020-06-30T21:00:00+00:00 JoVE no https://visualize.jove.com/3330833-circadian-rhythms-and-their-application-to-occupational-health-and-medicine monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11116.jpg Biological Clocks and Seasonal Responses The circadian—or biological—clock is an intrinsic, timekeeping, molecular mechanism that allows plants to coordinate physiological activities over 24-hour cycles called circadian rhythms. Photoperiodism is a collective term for the biological responses of plants to variations in the relative lengths of dark and light periods. The period of light-exposure is called the photoperiod. One example of photoperiodism in plants is seasonal flowering. Scientists believe that plants are cued to flower... https://www.jove.com/v/11116 165 2025-10-23T18:48:35+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12000.jpg Circadian Rhythms and Gene Regulation The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent years,... https://www.jove.com/v/12000 139 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12000.jpg Circadian Rhythms and Gene Regulation The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent years,... https://www.jove.com/v/13335 139 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14194.jpg Applications of RC Circuits A relaxation oscillator is one of the applications of RC circuits. A neon lamp relaxation oscillator comprises a capacitor, a resistor, a voltage source, and a lamp. The lamp acts like an open circuit, with infinite resistance until the potential difference across the lamp reaches a specific voltage. At that voltage, the lamp acts like a short circuit with zero resistance, and the capacitor discharges through the lamp, thus producing light. Once the capacitor is fully discharged through the... https://www.jove.com/v/14194 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15210.jpg Management of Insomnia The sleep cycle, an integral part of human health, consists of several stages with distinct characteristics and functions. It begins with a transition from wakefulness to sleep, known as the light sleep phase, followed by the restorative deep sleep phase, essential for physical recovery and growth. The cycle concludes with the Rapid Eye Movement (REM) phase, characterized by high brain activity and vivid dreaming. Insomnia, a prevalent sleep disorder, involves difficulty falling asleep, staying... https://www.jove.com/v/15210 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16606.jpg Chronopharmacokinetics: Circadian Rhythms and Influence on Drug Response Circadian rhythms are cyclic changes that are crucial in plasma drug concentrations. Various standard circadian parameters, including core body temperature, heart rate, and other cardiovascular factors, directly impact disease states and the therapeutic response to drug therapy. The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of... https://www.jove.com/v/16606 75 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54673.jpg Parallel Measurement of Circadian Clock Gene Expression and Hormone Secretion in Human Primary Cell Cultures Here, we describe settings to monitor in parallel circadian bioluminescence and the secretory activity of human islet cells and primary myotubes. For this, we employed lentiviral gene delivery of a luciferase core clock reporter, followed by in vitro synchronization and collection of outflow medium by continuous cell perifusion. https://www.jove.com/v/54673 413 2016-11-11T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59851.jpg Collecting Sleep, Circadian, Fatigue, and Performance Data in Complex Operational Environments Sleep loss and circadian misalignment contribute to numerous operational accidents and incidents. The effectiveness of countermeasures and work scheduling designs aimed at mitigating fatigue can be challenging to evaluate in operational environments. This manuscript summarizes an approach for collecting sleep, circadian, fatigue, and performance data in complex operational environments. https://www.jove.com/v/59851 516 2019-08-08T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60448.jpg Human Circadian Phenotyping and Diurnal Performance Testing in the Real World Here, we present a method to investigate diurnal rhythms in performance following accurate categorization of participants into circadian phenotype groups based on the Munich ChronoType Questionnaire, gold standard circadian phase biomarkers and actigraphic measures. https://www.jove.com/v/60448 616 2020-04-07T20:00:00+00:00 JoVE no https://visualize.jove.com/3407280-intermittent-confusional-states-as-an-expression-of-epileptic-seizures-in-elderly-patients monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15214.jpg Epilepsy and Seizures: Overview Epilepsy is a chronic neurological disease marked by recurrent, unpredictable seizures. These seizures are caused by abnormal electrical discharges in the brain, leading to behavior, sensation, or consciousness alterations. They can also cause transient impairment of awareness, interfering with daily activities. Various factors can trigger epilepsy, including genetic factors, brain damage, metabolic causes, and unknown etiology. Diagnosis of epilepsy involves electroencephalography (EEG), which... https://www.jove.com/v/15214 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15215.jpg Seizures: Classification Epilepsy is primarily characterized by unpredictable seizures, either provoked by an identifiable factor, such as injury or illness, or unprovoked, occurring spontaneously without apparent cause. Seizures are typically classified into two main categories: focal and generalized seizures. Focal Seizures Focal seizures originate from specific regions of the brain. These seizures are further sub-classified into two types: Focal aware seizures: In these seizures, the person remains conscious... https://www.jove.com/v/15215 73 JoVE no https://cloudfront.jove.com/files/ftp_upload/40950/40950_article_thumb_40950.jpg Seizures l: Introduction Understanding seizures and epilepsy relies on key definitions that help in recognizing, classifying, and managing these disorders. These definitions provide a framework for recognizing, classifying, and managing seizure disorders.DefinitionsA seizure is a sudden, abnormal burst of electrical activity in the brain that can cause changes in awareness, movement, sensation, or behavior, depending on the area involved. Epilepsy is a chronic condition characterized by recurrent, unprovoked seizures,... https://www.jove.com/v/40950 80 2026-04-15T17:37:41+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40951/40951_article_thumb_40951.jpg Seizures ll: Types Seizures are sudden bursts of abnormal electrical discharge in the brain that interfere with normal function. They are commonly divided into three groups: focal seizures, generalized seizures, and other types that do not fit neatly into either category.Focal SeizuresFocal seizures begin in a single brain region. When awareness is preserved, they are called focal aware seizures and may cause sensations such as tingling, unusual smells, or flashing lights. When awareness is impaired, they are... https://www.jove.com/v/40951 79 2026-04-13T21:37:32+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40954/40954_article_thumb_40954.jpg Epilepsy ll: Types Recurrent seizures, stemming from abnormal electrical activity in the brain, are the defining characteristic of epilepsy, a chronic neurological condition. Because seizure features vary greatly, epilepsy is classified using two systems: by seizure type and by epilepsy syndromes. These classifications enable clinicians to describe seizure patterns and select suitable treatment strategies.I. Classification by Seizure Type1. Focal EpilepsyFocal epilepsy begins in one hemisphere of the brain. https://www.jove.com/v/40954 82 2026-04-13T23:55:56+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/41017/41017_article_thumb_41017.jpg Hepatic Encephalopathy DefinitionHepatic encephalopathy is a reversible neurologic syndrome that results from advanced liver dysfunction or portosystemic shunting. It leads to disturbances in cognition, behavior, and motor function due to the brain’s exposure to gut-derived toxins that the liver fails to detoxify.EtiologyThis condition develops either in the setting of acute fulminant hepatitis or progressively during chronic liver disease, such as cirrhosis and portal hypertension. Portosystemic shunting—including... https://www.jove.com/v/41017 89 2026-05-14T20:10:40+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54883.jpg Interictal High Frequency Oscillations Detected with Simultaneous Magnetoencephalography and Electroencephalography as Biomarker of Pediatric Epilepsy High Frequency Oscillations (HFOs) have emerged as presurgical biomarkers for the identification of the epileptogenic zone in pediatric patients with medically refractory epilepsy. A methodology for the noninvasive recording, detection, and localization of HFOs with simultaneous scalp electroencephalography (EEG) and magnetoencephalography (MEG) is presented. https://www.jove.com/v/54883 622 2016-12-06T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64919.jpg Equipment Setup and Artifact Removal for Simultaneous Electroencephalogram and Functional Magnetic Resonance Imaging for Clinical Review in Epilepsy This article details simultaneous electroencephalogram and functional magnetic resonance imaging (EEG-fMRI) recording procedures that can be used in both clinical and research settings. EEG processing procedures to remove imaging artifacts for clinical review are also included. This study focuses on the example of epilepsy during the interictal period. https://www.jove.com/v/64919 623 2023-06-23T21:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66494.jpg Electromagnetic Source Imaging in Presurgical Evaluation of Children with Drug-Resistant Epilepsy Magnetoencephalography (MEG) and high-density electroencephalography (HD-EEG) are rarely recorded simultaneously, although they yield confirmatory and complementary information. Here, we illustrate the experimental setup for recording simultaneous MEG and HD-EEG and the methodology for analyzing these data aiming to localize epileptogenic and eloquent brain areas in children with drug-resistant epilepsy. https://www.jove.com/v/66494 597 2024-09-20T19:50:00+00:00 JoVE no https://visualize.jove.com/3467346-ontogenic-activation-of-a-fusion-gene-introduced-into-sea-urchin-eggs monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13559.jpg Methods of Nuclear Reprogramming Nuclear reprogramming is a process of transforming one cell type into an unrelated cell type by epigenetic changes that alter the cell’s original gene expression pattern. Such epigenetic changes force cells to express a different set of genes, which play a significant role in inducing transformation into other cell types. Nuclear reprogramming offers applications in reproductive cloning for livestock propagation and regenerative medicine — developing patient-specific cells for injury repair.<br... https://www.jove.com/v/13559 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50841.jpg High Throughput Microinjections of Sea Urchin Zygotes Microinjection is a common technique used to deliver DNA constructs, mRNAs, morpholino antisense oligonucleotides or other treatments into eggs, embryos, and cells of various species. https://www.jove.com/v/50841 760 2014-01-22T05:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52107.jpg Live Imaging of Innate Immune and Preneoplastic Cell Interactions Using an Inducible Gal4/UAS Expression System in Larval Zebrafish Skin Studying the earliest events of preneoplastic cell progression and innate immune cell interaction is pivotal to understand and treat cancer. Here we describe a method to conditionally induce epithelial cell transformations and the subsequent live imaging of innate immune cell interaction with HRASG12V expressing skin cells in zebrafish larvae. https://www.jove.com/v/52107 532 2015-02-03T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55113.jpg The Power of Simplicity: Sea Urchin Embryos as in Vivo Developmental Models for Studying Complex Cell-to-cell Signaling Network Interactions This video article details a straightforward in vivo methodology that can be used to systematically and efficiently characterize components of complex signaling pathways and regulatory networks in many invertebrate embryos. https://www.jove.com/v/55113 454 2017-02-16T22:00:00+00:00 JoVE no https://visualize.jove.com/3486081-the-high-tech-hand-surgery-interface monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/64796.jpg A Teleoperated Robotic System-Assisted Percutaneous Transiliac-Transsacral Screw Fixation Technique Teleoperated robotic system-assisted percutaneous transiliac-transsacral screw fixation is a feasible technique. Screw channels can be implemented with high accuracy owing to the excellent freedom of movement and stability of the robotic arms. https://www.jove.com/v/64796 357 2023-01-06T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66224.jpg Robotic Heller Myotomy for Advancements in Surgical Management of Achalasia The protocol presents a robotic approach to Heller myotomy for the treatment of achalasia. https://www.jove.com/v/66224 586 2024-02-16T22:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67096.jpg Automatic Surgery in Transcatheter Aortic Valve Replacement Using Augmented Reality This article presents the design and implementation of an automatic surgery module based on augmented reality (AR)- based 3D reconstruction. The system enables remote surgery by allowing surgeons to inspect reconstructed features and replicate surgical hand movements as if they were performing the surgery in close proximity. https://www.jove.com/v/67096 466 2024-08-09T21:25:00+00:00 JoVE no https://visualize.jove.com/3495462-a-convenient-system-for-the-serial-quantitation-of-viable-cells-measuring-luminescence-of-atp monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12018.jpg Real Time RT-PCR Real-time reverse transcription-polymerase chain reaction, or Real-time RT-PCR, is an analytical tool used to determine the expression level of target genes. The method involves converting mRNA to complementary DNA with the help of an enzyme known as reverse transcriptase, followed by the PCR amplification of the cDNA. These two processes can be performed simultaneously in a single tube or separately as a two-step reaction. The real-time quantification of the number of amplified products is... https://www.jove.com/v/12018 177 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50645.jpg Viability Assays for Cells in Culture Therapeutic compounds are often first examined in vitro with viability assays. Blind cell counts by a human observer can be highly sensitive to small changes in cell number but do not assess function. Computerized viability assays, as described here, can assess both structure and function in an objective manner. https://www.jove.com/v/50645 723 2014-01-20T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53867.jpg A Simple Bioassay for the Evaluation of Vascular Endothelial Growth Factors We describe a simple cell-based bioassay for detecting, quantifying and monitoring the activity of members of the vascular endothelial growth factor family of ligands. The assay uses chimeric receptors expressed in a factor-dependent cell line to provide a semi-quantitative or quantitative assessment of receptor binding and cross-linking by the ligand. https://www.jove.com/v/53867 544 2016-03-15T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54350.jpg Comparison of Three Different Methods for Determining Cell Proliferation in Breast Cancer Cell Lines This protocol describes the use of three different methods for analyzing cell proliferation in breast cancer cell lines. This includes the use of conventional cell counting, luminescence-based cell viability, and cell counting through the use of a cell imager. Each offers advantages for the reproducible measurement of cell proliferation. https://www.jove.com/v/54350 755 2016-09-03T20:00:00+00:00 JoVE no https://visualize.jove.com/3500656-perspectives-of-an-electronic-data-processing-controlled-anesthesia-protocol monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14748.jpg Local Anesthetics: Clinical Application as Epidural Anesthesia Epidural anesthetics are administered in the fat-filled epidural space, the outermost part of the spinal canal. This technique is commonly employed for pain management and anesthesia during lower abdomen and pelvis surgeries or labor and delivery. Since epidural anesthetics can be infused through an epidural catheter, all types of drugs, including short-acting ones, can be administered. Chloroprocaine and lidocaine are examples of short and long-duration anesthetics, respectively. Bupivacaine... https://www.jove.com/v/14748 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15188.jpg General Anesthesia: Overview Anesthesia is a medical procedure that uses drugs for CNS suppression to enable painless surgeries and procedures. The selection of anesthetics is influenced by their pharmacokinetic properties, side effects, and patient characteristics. Various types of anesthesia include general, local, regional, spinal, and inhalational. General anesthesia induces unconsciousness in the whole body, while the others target specific areas or sensations. It is administered to minimize adverse effects, maintain... https://www.jove.com/v/15188 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15189.jpg Stages of General Anesthesia Various sedation levels offer significant advantages in facilitating procedural interventions for patients undergoing medical or invasive surgical procedures. These levels span from anxiolysis to general anesthesia, providing a spectrum of sedative effects to cater to specific patient needs. Anxiolysis reduces anxiety and is achieved through minimal sedation, enabling patients to remain awake and responsive while feeling more at ease during the procedure. This level can benefit minor... https://www.jove.com/v/15189 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15190.jpg Parenteral Anesthetics: Overview Intravenous anesthetics are drugs administered parenterally to induce anesthesia or sedation. Propofol is a widely used agent formulated as a 1% emulsion in soybean oil, glycerol, and egg phosphatide. It induces rapid anesthesia primarily due to its rapid distribution from the bloodstream to target tissues and is metabolized in the liver. However, it can cause significant pain on injection and hypertriglyceridemia. Fospropofol, a water-based prodrug of propofol, lacks these adverse effects. https://www.jove.com/v/15190 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54436.jpg Use of a Low-flow Digital Anesthesia System for Mice and Rats Here, we present a protocol to more safely and efficiently administer anesthetic gas to mice using a digital, low flow anesthesia system utilizing a syringe-driven direct injection vaporizer. https://www.jove.com/v/54436 486 2016-09-07T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56881.jpg Recording Brain Electromagnetic Activity During the Administration of the Gaseous Anesthetic Agents Xenon and Nitrous Oxide in Healthy Volunteers Simultaneous magnetoencephalography and electroencephalography provides a useful tool to search for common and distinct macro-scale mechanisms of reductions in consciousness induced by different anesthetics. This paper illustrates the empirical methods underlying the recording of such data from healthy humans during N-Methyl-D-Aspartate-(NMDA)-receptor-antagonist-based anesthesia during inhalation of nitrous oxide and xenon. https://www.jove.com/v/56881 892 2018-01-13T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61311.jpg Use of an Integrated Low-Flow Anesthetic Vaporizer, Ventilator, and Physiological Monitoring System for Rodents Here, we present a protocol to safely and effectively administer anesthetic gas to mice using a digital, low flow anesthesia system with integrated ventilator and physiological monitoring modules. https://www.jove.com/v/61311 417 2020-07-09T20:00:00+00:00 JoVE no https://visualize.jove.com/3503807-analysis-of-the-spread-of-ambulatory-electrocardiography-in-italy monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13286.jpg Pulse rhythm Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding. Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle... https://www.jove.com/v/13286 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15273.jpg Electrocardiogram An electrocardiogram (ECG or EKG) is a critical diagnostic tool that records the electrical signals produced by the heart during each heartbeat. This recording is achieved through electrodes placed strategically on the arms, legs, and chest. The electrocardiograph amplifies these signals and produces 12 distinct tracings, offering a comprehensive understanding of the heart's electrical activity. Three major waveforms are present in a typical ECG recording: the P wave, the QRS complex, and the T... https://www.jove.com/v/15273 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15275.jpg Correlation between ECG and Cardiac Cycle The electrical signals recorded on an electrocardiogram (ECG) occur before the mechanical processes of contraction and relaxation during the cardiac cycle. A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before... https://www.jove.com/v/15275 85 2025-05-15T16:16:28+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17877.jpg Electrocardiogram Fundamentals Introduction An electrocardiogram (ECG) is a diagnostic tool for identifying cardiac conditions such as arrhythmias, conduction abnormalities, and myocardial ischemia. Definition An electrocardiogram (ECG) visualizes the heart's electrical activity by tracing the electrical movement associated with each heartbeat on a graph or monitor. As the heart beats, an electrical wave passes through it, correlating with the cardiac cycle events. Parts of an ECG An ECG utilizes electrodes on the skin to... https://www.jove.com/v/17877 88 JoVE no https://cloudfront.jove.com/files/ftp_upload/17887/17887_article_thumb_17887.jpg Holter Monitor: 24-Hour Monitoring Holter monitoring is a continuous electrocardiography (ECG) recording that tracks the heart's electrical activity over an extended period, generally 24 to 48 hours. This noninvasive diagnostic tool detects irregular heart rhythms that may not be captured during a standard ECG performed in a clinical setting.DeviceThe Holter monitor is a portable, small device connected to several electrodes on the patient's chest. These electrodes detect the heart's electrical signals and transmit them to the... https://www.jove.com/v/17887 83 2025-06-19T16:09:27+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17942/17942_article_thumb_17942.jpg Dysrhythmias V: Evaluating Dysrhythmias Dysrhythmias, also known as arrhythmias, are disturbances in the heart's rhythm that range from benign to life-threatening. A thorough evaluation is crucial for appropriate management and involves a comprehensive medical history, physical examination, and various diagnostic tests.Medical HistorySymptoms: Collect detailed information on palpitations, dizziness, syncope, chest pain, and fatigue. Note their onset, frequency, and triggers.Previous Cardiac Issues: Document any history of heart... https://www.jove.com/v/17942 90 2025-06-19T16:36:46+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50124.jpg A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis Continuous 12-lead electrocardiographic (ECG) monitoring can identify transient myocardial ischemia, even when asymptomatic, among patients with suspected acute coronary syndrome (ACS). In this article we describe our method for initiating patient monitoring using a Holter device, downloading the ECG data for off-line analysis, and how to utilize the ECG software to identify transient ischemia. https://www.jove.com/v/50124 1091 2012-12-28T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60715.jpg Patient Directed Recording of a Bipolar Three-Lead Electrocardiogram using a Smartwatch with ECG Function We describe a protocol for the patient-directed registration of a three lead bipolar electrocardiogram by a smartwatch that functions identically to the Einthoven leads from standard electrocardiograms. This enables patients to record electrocardiograms on their own immediately after the onset of symptoms. https://www.jove.com/v/60715 303 2019-12-11T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64683.jpg Evaluation of Hydration Status by Bioelectrical Impedance Vector Analysis in Patients with Ischemic Heart Disease Undergoing Exercise Stress Test Hydration status imbalances can have a short-term effect on direct and indirect determinants of oxygen uptake and pulse, and morbidity and mortality prognostic factors in ischemic heart disease. This protocol describes the technique for assessment of hydration status through bioelectrical impedance vector analysis and cardiopulmonary response during exercise stress test. https://www.jove.com/v/64683 621 2023-09-22T20:50:00+00:00 JoVE no https://visualize.jove.com/3556506-amygdala-kindling-modifies-interhemispheric-dopaminergic-asymmetry monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14915.jpg Functional Brain Systems: Limbic System The limbic system, often called the "emotional brain," is a complex set of structures located deep within the brain. The intricate network of the limbic system supports a wide range of psychological functions, from emotional regulation to memory formation and sensory processing. This functional brain region encompasses specific parts of the diencephalon and the cerebrum, integrating the higher mental functions of the cerebral cortex with the primitive emotional responses of the deep brain... https://www.jove.com/v/14915 75 2025-06-13T16:15:56+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18185.jpg Role of Amygdala in Memory The amygdala is a small, almond-shaped structure responsible for processing and storing memories, particularly those linked to emotions like fear and stress. It plays an essential role in the brain's response to emotionally significant events and often enhances memory formation by triggering stress hormone release. The amygdala is vital for encoding and retrieving memories associated with fear or stress, a process that is adaptive by helping organisms avoid dangerous situations. One of the... https://www.jove.com/v/18185 76 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53628.jpg Ex Vivo Optogenetic Dissection of Fear Circuits in Brain Slices Optogenetic approaches are widely used to manipulate neural activity and assess the consequences for brain function. Here, a technique is outlined that upon in vivo expression of the optical activator Channelrhodopsin, allows for ex vivo analysis of synaptic properties of specific long range and local neural connections in fear-related circuits. https://www.jove.com/v/53628 673 2016-04-06T00:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59310.jpg Evaluation of Hemisphere Lateralization with Bilateral Local Field Potential Recording in Secondary Motor Cortex of Mice We present in vivo electrophysiological recording of the local field potential (LFP) in bilateral secondary motor cortex (M2) of mice, which can be applied to evaluate hemisphere lateralization. The study revealed altered levels of synchronization between the left and right M2 in APP/PS1 mice compared to WT controls. https://www.jove.com/v/59310 423 2019-07-31T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64113.jpg Using a Bipolar Electrode to Create a Temporal Lobe Epilepsy Mouse Model by Electrical Kindling of the Amygdala The amygdala plays a key role in temporal lobe epilepsy, which originates in and propagates from this structure. This article provides a detailed description of the fabrication of deep brain electrodes with both recording and stimulating functions. It introduces a model of medial temporal lobe epilepsy originating from the amygdala. https://www.jove.com/v/64113 589 2022-06-29T21:30:00+00:00 JoVE no https://visualize.jove.com/3560941-diurnal-fluctuation-in-saliva-aldosterone-concentration monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10893.jpg Hormonal Regulation The renin-aldosterone system is an endocrine system which guides the renal absorption of water and electrolytes, thus managing blood pressure and osmoregulation. Activation of the system begins in the kidneys with a small cluster of cells adjacent to the afferent and efferent blood vessels of the renal corpuscle. As the nephrons are filtering blood, juxtaglomerular cells monitor blood pressure. If they detect a decrease in pressure, they release the hormone renin into the bloodstream. <br... https://www.jove.com/v/10893 93 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16269.jpg Regulation of Water Intake Osmolality refers to the number of solute particles per kilogram of solvent in a solution. Plasma osmolality specifically indicates the total number of solute particles per kilogram of water in blood plasma. This value reflects the body's hydration status and is tightly regulated through mechanisms controlling water intake and output. While water consumption is a conscious decision, the body has intrinsic regulatory systems to maintain fluid balance. Dehydration, a state of water deficit... https://www.jove.com/v/16269 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16270.jpg Regulation of Water Output The human body predominantly expels water through the urinary system. On average, an individual generates around 1.5 liters of urine each day. This amount can fluctuate based on how well a person is hydrated, but a critical minimum quantity of urine must be produced to ensure the body's proper functioning. Daily, the kidneys remove 600 to 1200 milliosmoles of dissolved substances, effectively excreting excess minerals and water-soluble toxins such as creatinine, urea, and uric acid from the... https://www.jove.com/v/16270 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16275.jpg Regulation of Sodium and Potassium The regulation of sodium and potassium ion concentrations in the human body is a complex process governed primarily by hormones such as aldosterone, antidiuretic hormone (ADH), and atrial natriuretic peptide (ANP). Sodium Regulation Sodium ions make up approximately 90% of extracellular cations, with a normal blood plasma concentration of 136–148 mEq/L. A decrease in blood volume and pressure triggers the release of renin from granular cells in the juxtaglomerular complex (JGC), primarily in... https://www.jove.com/v/16275 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16606.jpg Chronopharmacokinetics: Circadian Rhythms and Influence on Drug Response Circadian rhythms are cyclic changes that are crucial in plasma drug concentrations. Various standard circadian parameters, including core body temperature, heart rate, and other cardiovascular factors, directly impact disease states and the therapeutic response to drug therapy. The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of... https://www.jove.com/v/16606 75 JoVE no https://cloudfront.jove.com/files/ftp_upload/17177/17177_article_thumb_17177.jpg Dosage Regimen: Multiple Oral Dosage Understanding how a drug's concentration fluctuates within the body over time is crucial in pharmacokinetics, particularly with multiple oral doses. A graphical representation of multiple oral dosages provides insight into these dynamics. Typical accumulation curves of a drug's concentration in the body reveal a sawtooth pattern, indicating periodic peaks and troughs correlating with each dose administration and the drug's subsequent elimination.The plasma concentration at any time during an... https://www.jove.com/v/17177 85 2025-10-03T14:00:20+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50815.jpg Collecting Saliva and Measuring Salivary Cortisol and Alpha-amylase in Frail Community Residing Older Adults via Family Caregivers We demonstrate: (1) procedures for collection of salivary samples in cognitive impaired older adults by family caregivers in the home setting, (2) procedures for measuring stress activity via salivary cortisol and alpha amylase, and (3) representative profiles. Protocols that allow researchers to study stress-linked processes advance our understanding of biological sensitivity and susceptibility. https://www.jove.com/v/50815 505 2013-12-18T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59272.jpg Measuring Biophysical and Psychological Stress Levels Following Visitation to Three Locations with Differing Levels of Nature The purpose of this paper is to identify changes in stress levels after visitation to three different settings and to describe the methods used in identifying stress levels based on measures of salivary cortisol, α-amylase, and a psychological self-report... https://www.jove.com/v/59272 333 2019-06-19T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67530.jpg Through-the-Wall Blood Sampling Method to Minimize Sleep Disruption in Clinical Settings Here, we present a through-the-wall, minimally invasive method to sample blood during sleep in clinical settings. https://www.jove.com/v/67530 399 2025-06-13T21:00:00+00:00 JoVE no https://visualize.jove.com/3568057-twenty-four-hour-electrocardiographic-study-in-the-active-very-elderly monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13286.jpg Pulse rhythm Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding. Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle... https://www.jove.com/v/13286 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15273.jpg Electrocardiogram An electrocardiogram (ECG or EKG) is a critical diagnostic tool that records the electrical signals produced by the heart during each heartbeat. This recording is achieved through electrodes placed strategically on the arms, legs, and chest. The electrocardiograph amplifies these signals and produces 12 distinct tracings, offering a comprehensive understanding of the heart's electrical activity. Three major waveforms are present in a typical ECG recording: the P wave, the QRS complex, and the T... https://www.jove.com/v/15273 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17877.jpg Electrocardiogram Fundamentals Introduction An electrocardiogram (ECG) is a diagnostic tool for identifying cardiac conditions such as arrhythmias, conduction abnormalities, and myocardial ischemia. Definition An electrocardiogram (ECG) visualizes the heart's electrical activity by tracing the electrical movement associated with each heartbeat on a graph or monitor. As the heart beats, an electrical wave passes through it, correlating with the cardiac cycle events. Parts of an ECG An ECG utilizes electrodes on the skin to... https://www.jove.com/v/17877 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17878.jpg ECG Interpretation of Rhythms An electrocardiogram (ECG)graphically represents the heart's electrical activity on ECG paper or a monitor. Components of the Electrocardiogram The primary components of a normal ECG waveform in Normal sinus rhythm(NSR) include the P wave, PR interval, QRS complex, ST segment, T wave, and occasionally a U wave. ECG waveforms are divided by vertical and horizontal lines at standard intervals. The horizontal axis measures time and rate, and the vertical axis measures amplitude or voltage. When... https://www.jove.com/v/17878 84 JoVE no https://cloudfront.jove.com/files/ftp_upload/17887/17887_article_thumb_17887.jpg Holter Monitor: 24-Hour Monitoring Holter monitoring is a continuous electrocardiography (ECG) recording that tracks the heart's electrical activity over an extended period, generally 24 to 48 hours. This noninvasive diagnostic tool detects irregular heart rhythms that may not be captured during a standard ECG performed in a clinical setting.DeviceThe Holter monitor is a portable, small device connected to several electrodes on the patient's chest. These electrodes detect the heart's electrical signals and transmit them to the... https://www.jove.com/v/17887 83 2025-06-19T16:09:27+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17942/17942_article_thumb_17942.jpg Dysrhythmias V: Evaluating Dysrhythmias Dysrhythmias, also known as arrhythmias, are disturbances in the heart's rhythm that range from benign to life-threatening. A thorough evaluation is crucial for appropriate management and involves a comprehensive medical history, physical examination, and various diagnostic tests.Medical HistorySymptoms: Collect detailed information on palpitations, dizziness, syncope, chest pain, and fatigue. Note their onset, frequency, and triggers.Previous Cardiac Issues: Document any history of heart... https://www.jove.com/v/17942 90 2025-06-19T16:36:46+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50124.jpg A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis Continuous 12-lead electrocardiographic (ECG) monitoring can identify transient myocardial ischemia, even when asymptomatic, among patients with suspected acute coronary syndrome (ACS). In this article we describe our method for initiating patient monitoring using a Holter device, downloading the ECG data for off-line analysis, and how to utilize the ECG software to identify transient ischemia. https://www.jove.com/v/50124 1091 2012-12-28T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58823.jpg Multi-Modal Home Sleep Monitoring in Older Adults Here, we present a protocol to improve the quality of data from home sleep testing by providing a method to enhance instructions through a structured participant visit. This protocol includes the implementation of a step-by-step educational manual with photos to ensure proper placement of equipment. https://www.jove.com/v/58823 460 2019-01-26T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60715.jpg Patient Directed Recording of a Bipolar Three-Lead Electrocardiogram using a Smartwatch with ECG Function We describe a protocol for the patient-directed registration of a three lead bipolar electrocardiogram by a smartwatch that functions identically to the Einthoven leads from standard electrocardiograms. This enables patients to record electrocardiograms on their own immediately after the onset of symptoms. https://www.jove.com/v/60715 303 2019-12-11T21:00:00+00:00 JoVE no https://visualize.jove.com/3582780-ontogenetic-change-in-the-analysis-of-sound-frequency-in-the-infant-rat monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10855.jpg The Cochlea The cochlea is a coiled structure in the inner ear that contains hair cells—the sensory receptors of the auditory system. Sound waves are transmitted to the cochlea by small bones attached to the eardrum called the ossicles, which vibrate the oval window that leads to the inner ear. This causes fluid in the chambers of the cochlea to move, vibrating the basilar membrane. The basilar membrane extends from the basal end of the cochlea near the oval window to the apical end at its tip. Although... https://www.jove.com/v/10855 73 2025-10-23T18:49:24+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52420.jpg Infant Auditory Processing and Event-related Brain Oscillations High-density electroencephalography (dEEG) is being used increasingly to study brain development and plasticity in the early years of life. Here we present an application of sophisticated analysis techniques that builds on traditional EEG recording to understand the oscillatory dynamics of rapid auditory processing in the infant brain. https://www.jove.com/v/52420 394 2015-07-01T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56678.jpg Auditory Brainstem Response and Outer Hair Cell Whole-cell Patch Clamp Recording in Postnatal Rats This protocol describes methods to record the auditory brainstem response from postnatal rat pups. To examine the functional development of outer hair cells, the experimental procedure of whole-cell patch clamp recording in isolated outer hair cells is described step-by-step. https://www.jove.com/v/56678 563 2018-05-24T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57993.jpg Simple Surgical Induction of Conductive Hearing Loss with Verification Using Otoscope Visualization and Behavioral Clap Startle Response in Rat Here, we present a protocol to establish a replicable conductive hearing loss induction via surgical tympanic membrane puncture and verification by otoscope visualization and behavioral assessment by clap startle. https://www.jove.com/v/57993 387 2019-10-26T19:30:00+00:00 JoVE no https://visualize.jove.com/3613550-quantum-noise-in-x-ray-image-intensifiers monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12988.jpg NMR Spectrometers: Resolution and Error Correction When magnetic nuclei in a sample achieve resonance and undergo relaxation, the signal detected in NMR is an approximately exponential free induction decay. Fourier transform of an exponential decay yields a Lorentzian peak in the frequency domain. Lorentzian peaks in an NMR spectrum are defined by their amplitude, full width at half maximum, and position, where the peak width is governed by the spin-spin relaxation time alone. In real experiments, however, the applied magnetic field is rendered... https://www.jove.com/v/12988 74 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13167.jpg NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences A pulse is a short burst of radio waves distributed over a range of frequencies that simultaneously excites all the nuclei in the sample. Upon passing a radio frequency pulse along the x-axis, the nuclei absorb energy corresponding to their Larmor frequencies and achieve resonance. This shifts the net magnetization vector from the z-axis toward the transverse plane. This angle of rotation of the magnetization vector, or the flip angle, is proportional to the duration and intensity of the pulse. https://www.jove.com/v/13167 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13863.jpg X-ray Imaging German physicist Wilhelm Röntgen (1845–1923) was experimenting with electrical current when he discovered that a mysterious and invisible "ray" would pass through his flesh but leave an outline of his bones on a screen coated with a metal compound. In 1895, Röntgen made the first durable record of the internal parts of a living human: an "X-ray" image (as it came to be called) of his wife’s hand. Scientists worldwide quickly began their own experiments with X-rays, and by 1900, X-ray was widely... https://www.jove.com/v/13863 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60001.jpg X-ray Beam Induced Current Measurements for Multi-Modal X-ray Microscopy of Solar Cells A setup for X-ray beam induced current measurements at synchrotron beamlines is described. It unveils the nanoscale performance of solar cells and extends the suite of techniques for multi-modal X-ray microscopy. From wiring to signal-to-noise optimization, it is shown how to perform state-of-the-art XBIC measurements at a hard X-ray microprobe. https://www.jove.com/v/60001 616 2019-08-20T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64252.jpg High Spatial Resolution Chemical Imaging of Implant-Associated Infections with X-ray Excited Luminescence Chemical Imaging Through Tissue Here, we present a protocol for high-resolution optical detection of chemical information around implanted medical devices with X-ray excited luminescence chemical imaging (XELCI). This novel imaging technique is developed in our lab which enables studying implant-associated infection biochemistry. https://www.jove.com/v/64252 468 2022-09-30T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65972.jpg Troubleshooting and Quality Assurance in Hyperpolarized Xenon Magnetic Resonance Imaging: Tools for High-Quality Image Acquisition Here, we present a protocol for obtaining high-quality hyperpolarized xenon-129 magnetic resonance images, covering hardware, software, data acquisition, sequence selection, data management, k-space utilization, and noise analysis. https://www.jove.com/v/65972 595 2024-01-05T22:10:00+00:00 JoVE no https://visualize.jove.com/3618006-memory-a-new-dimension-in-surgical-interventions monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18174.jpg Storage A schema is a mental framework that helps individuals organize and interpret information. Schemata, formed from previous experiences, influence how we process new information: how we encode it, the inferences we make, and how we retrieve it. For instance, a schema for what a typical classroom looks like might include desks, a teacher's desk, a whiteboard, and students in such an environment. This expectation helps us quickly understand and navigate new classrooms without needing to analyze each... https://www.jove.com/v/18174 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56584.jpg Surgical Training for the Implantation of Neocortical Microelectrode Arrays Using a Formaldehyde-fixed Human Cadaver Model We designed a procedure in which a formaldehyde-fixed human cadaver is used to assist neurosurgeons in training for the implantation of microelectrode arrays into the neocortex of the human brain. https://www.jove.com/v/56584 491 2017-11-19T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59592.jpg Translational Brain Mapping at the University of Rochester Medical Center: Preserving the Mind Through Personalized Brain Mapping This article provides an overview of a multi-modal brain mapping program designed to identify regions of the brain that support critical cognitive functions in individual neurosurgery patients. https://www.jove.com/v/59592 792 2019-08-12T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66227.jpg Pioneering Patient-Specific Approaches for Precision Surgery Using Imaging and Virtual Reality Advancements in endovascular treatment have replaced complex open surgical procedures with minimally invasive options, like valve replacement and aneurysm repair. This paper proposes using three-dimensional (3D) modeling and virtual reality to aid in C-arm positioning, angle measurements, and roadmap generation for neuro-interventional catheterization lab procedural planning, minimizing procedure time. https://www.jove.com/v/66227 378 2024-04-05T20:20:00+00:00 JoVE no https://visualize.jove.com/3646621-replicated-testing-of-the-nursing-technology-model monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12950.jpg Theoretical Foundations of Nursing Practice Theories play an essential role in organizing patient care. Theories refer to a proposed or followed belief, policy, or procedure that is the basis for action. Nursing theories are knowledge-based concepts that guide nurses' actions, influence nursing education and practice, and allow nurses to care for their patients. Theories provide a perspective to assess patients' conditions and organize data and methods. They also assist in analyzing and interpreting information. They represent a... https://www.jove.com/v/12950 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12958.jpg Current Trends in Nursing II Trends in nursing are multifactorial and associated with changes in society, within the nursing profession, and in other professions. Notably, telehealth and remote nursing contribute to successful healthcare delivery for numerous patients and help reduce stress for nurses due to nursing shortages. Nurses can reach patients, monitor their conditions, and interact with them using computers, audio, visual accessories, and telephones—for example, remote patient monitoring systems. Likewise,... https://www.jove.com/v/12958 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13532.jpg Fundamentals of Nursing Process I The nursing process is the core of practice for every registered nurse to deliver holistic, patient-focused care. The following are the five steps in the nursing process. Assessment: A nurse uses an organized, dynamic way to collect and analyze data about the patient. It includes the patient's physiological data and psychological, sociocultural, spiritual, economic, and lifestyle factors. Diagnosis: A clinical judgment about the patient's condition and their reaction toward actual or... https://www.jove.com/v/13532 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13539.jpg Data Validation Data validation is an essential part of a comprehensive assessment. Validation is confirming or verifying and opening the door to gathering more assessment data as it clarifies vague or unclear data. The process of checking and verifying the collected information is called data validation. The primary purpose of data validation is to ensure data is as free from error, bias, and misinterpretation as possible. Nursing assessment guides are generally based on holistic models rather than medical... https://www.jove.com/v/13539 63 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13553.jpg Nursing Implementation Implementation is the execution of the nursing care plan developed during the planning phase. The five steps to implementing effective nursing care include reassessing the patient, reviewing and revising the existing nursing care plan, organizing the resources and care delivery, anticipating and preventing complications, and implementing nursing interventions. The first step is reassessing the client, a continuous process every time a nurse interacts with a patient, obtains new data,... https://www.jove.com/v/13553 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14682.jpg The Scientific Method in Nursing Process The scientific method provides the foundation for any research. It is the most reliable and objective of all forms of gaining knowledge and guides in applying research-based evidence in practice and conducting future research. When using research findings to change practice, one must understand the process used to guide a study. The scientific method is a systematic, step-by-step process that supports the data's validity, reliability, and generalizability. As a result, findings can be safely... https://www.jove.com/v/14682 78 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60330.jpg A Computerized Functional Skills Assessment and Training Program Targeting Technology Based Everyday Functional Skills This training protocol uses computerized training to teach technology-related everyday functional skills. These skills include financial skills, travel and transit, as well as medication management. https://www.jove.com/v/60330 451 2020-02-13T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66905.jpg Using Simulation Models to Train Clinicians in the Use of Point-of-Care Ultrasound The present protocol describes an ideal solution to train novices in the use of point-of-care ultrasound devices for the practical clinical skill of visually assessing distinct individual anatomical vascular conditions prior to and during an intended venous vascular cannulation using point-of-care ultrasound in a patient. https://www.jove.com/v/66905 304 2024-08-09T20:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67890.jpg Development of a Benchtop Model for Evaluating the Compatibility of Wound Dressing Materials with Negative Pressure Wound Therapy Systems This study presents a benchtop model designed to evaluate the compatibility of wound dressing materials with negative pressure wound therapy systems by assessing pressure and fluid collection over 72 h under continuous and intermittent pressure settings. https://www.jove.com/v/67890 405 2025-05-02T20:40:00+00:00 JoVE no https://visualize.jove.com/3689567-psychotropic-effects-of-angiotensin-ii-and-iii-in-rats-locomotor-and-exploratory-vs-cognitive-behaviour monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2705.jpg The Successive Alleys Test of Anxiety in Mice and Rats The plus-maze measures anxiety-like behaviour in rodents. There are two opposite closed and two opposite open arms; anxious rodents avoid the open arms. The central area is neither completely open nor closed, so time spent here is ambiguous and difficult to interpret. Here a modification of the plus-maze protocol eliminating this area is described. https://www.jove.com/v/2705 305 2013-06-17T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53866.jpg Receptor Autoradiography Protocol for the Localized Visualization of Angiotensin II Receptors Here we present a protocol to describe the localization of angiotensin II Type 1 receptors in the rat brain by quantitative, densitometric, in vitro receptor autoradiography using an iodine-125 labeled analog of angiotensin II. https://www.jove.com/v/53866 723 2016-06-07T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56428.jpg Testing Animal Anxiety in Rats: Effects of Open Arm Ledges and Closed Arm Wall Transparency in Elevated Plus Maze Test Rats' anxiety-like behavior tested by the elevated plus maze varies highly depending on the testing environment. Here we show how apparatus settings, especially arm structure, affect behavior on the maze, and we explain a reliable protocol to detect effects of anxiolytic drugs. This report will contribute to anxiety research. https://www.jove.com/v/56428 474 2018-06-29T19:30:00+00:00 JoVE no https://visualize.jove.com/3757612-sources-of-age-differences-in-speed-of-processing monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11069.jpg Stereotypes, Prejudice, and Discrimination Humans are very diverse and although we share many similarities, we also have many differences. The social groups we belong to help form our identities (Tajfel, 1974). These differences may be difficult for some people to reconcile, which may lead to prejudice toward people who are different. Prejudice is a negative attitude and feeling toward an individual based solely on one’s membership in a particular social group (Allport, 1954; Brown, 2010). Prejudice is common against people who are... https://www.jove.com/v/11069 175 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17779.jpg Parallel Processing The brain processes sensory information rapidly due to parallel processing, which involves sending data across multiple neural pathways at the same time. This method allows the brain to manage various sensory qualities, such as shapes, colors, movements, and locations, all concurrently. For instance, when observing a forest landscape, the brain simultaneously processes the movement of leaves, the shapes of trees, the depth between them, and the various shades of green. This enables a quick and... https://www.jove.com/v/17779 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18562.jpg Information Processing Approach The information-processing theory of cognitive development centers on fundamental mental processes, including attention, memory, and problem-solving skills. Researchers in this field examine how cognitive abilities, such as working memory, evolve and influence children's overall development. Studies indicate that children with stronger working memory tend to excel in reading comprehension, math, and problem-solving compared to peers with less efficient memory skills. Low working memory is also... https://www.jove.com/v/18562 90 JoVE no https://cloudfront.jove.com/files/ftp_upload/19923/19923_article_thumb_19923.jpg Automatic Processing and Automatic Social Behavior Automatic processing refers to the cognitive operations that occur without conscious intent or awareness, playing a fundamental role in shaping social cognition and behavior. These processes enable individuals to navigate complex social environments efficiently by relying on mental shortcuts and pre-existing knowledge structures known as schemas. One of the most influential mechanisms underlying automatic processing is priming, which subtly activates mental representations through exposure to... https://www.jove.com/v/19923 88 2025-09-18T17:24:15+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50942.jpg Assessment of Age-related Changes in Cognitive Functions Using EmoCogMeter, a Novel Tablet-computer Based Approach We tested the usability of a tablet-computer-based application (EmoCogMeter) in investigating the effects of age on cognition. Results show an age-related cognitive decline, thereby proving the usability of our application. Findings underline the great clinical and practical potential of a tablet-based application for detection and monitoring of cognitive dysfunction. https://www.jove.com/v/50942 613 2014-02-14T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51003.jpg A Method for Investigating Age-related Differences in the Functional Connectivity of Cognitive Control Networks Associated with Dimensional Change Card Sort Performance This video presents a method of examining age-related changes in functional connectivity of cognitive control networks engaged by targeted tasks/processes. The technique is based on multi-variate analysis of fMRI data. https://www.jove.com/v/51003 541 2014-05-07T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60417.jpg An Experimental Paradigm for Measuring the Effects of Ageing on Sentence Processing Here, we present a protocol to examine the age-related decline in sentence processing using a maze task that allowed us to localize the processing difficulty at each word of the sentences during reading. https://www.jove.com/v/60417 270 2019-10-25T21:30:00+00:00 JoVE no https://visualize.jove.com/3772782-particulate-and-microbial-contamination-of-intraocular-irrigation-solutions monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13239.jpg Hand hygiene Asepsis is the practice of preventing or breaking the chain of infection. The nurse employs aseptic techniques to prevent the spread of microorganisms and reduce the risk of diseases. Hand hygiene is the cornerstone of aseptic techniques and is classified into medical and surgical asepsis. Medical asepsis includes hand hygiene and the use of gloves. Surgical asepsis, or the sterile technique, refers to practices that render and keep objects and areas free of microorganisms. Hand washing... https://www.jove.com/v/13239 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13241.jpg Cleaning, Sterilization, and Disinfection Cleaning, disinfection, and sterilization are the methods that help to break the infection chain and prevent disease. Cleaning The cleaning process usually involves using water with detergents or enzymatic cleaner and removing foreign material from objects and surfaces, including organic material such as body fluids or inorganic material like soil. Cleaning is performed before high-level disinfection and sterilization because foreign materials on the cover of the devices interfere with process... https://www.jove.com/v/13241 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14480.jpg Glaucoma: Overview Glaucoma is an eye condition characterized by increased intraocular pressure that damages the retina and optic nerve, leading to irreversible blindness if left untreated. The human eye has various components, including the cornea, iris, pupil, lens, and optic nerve. Aqueous humor is secreted by the epithelium of the ciliary body in the posterior chamber and flows through the trabecular meshwork and canal of Schlemm, maintaining normal intraocular pressure. The trabecular meshwork and the canal... https://www.jove.com/v/14480 85 JoVE no https://cloudfront.jove.com/files/ftp_upload/17259/17259_article_thumb_17259.jpg Ophthalmic Drug Delivery Systems Ophthalmic drug delivery faces major limitations due to poor absorption across the corneal membrane. This process is primarily driven by diffusion and is influenced by two main factors: the physicochemical properties of the drug and tear drainage. Most ophthalmic drugs, such as pilocarpine, epinephrine, atropine, and local anesthetics, are weak bases. They are typically formulated at an acidic pH to enhance chemical stability. However, this leads to high ionization, reducing their ability to... https://www.jove.com/v/17259 83 2026-02-12T19:16:56+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19519/19519_article_thumb_19519.jpg Physical Methods for Controlling Microbial Growth: Radiation and Filtration Radiation and filtration are essential tools for microbial control, targeting microorganisms through distinct mechanisms. Radiation eliminates microbes by damaging their DNA, either killing them or inhibiting their growth. Based on wavelength, radiation is classified into two types: nonionizing and ionizing radiation.Non-ionizing radiation, such as UV radiation (200–400 nm), is absorbed by DNA, causing defects that effectively disinfect surfaces, air, and water, including safety cabinets. https://www.jove.com/v/19519 86 2025-06-12T16:42:55+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40793/40793_article_thumb_40793.jpg Microbiome of the Eye The human eye has a specialized microbiota that reflects its unique anatomical and immunological environment. This low-biomass microbial community predominantly colonizes the conjunctiva and eyelid margins, playing a vital role in ocular surface homeostasis and defense. Despite its proximity to the richly colonized facial skin, the ocular surface maintains a distinct microbial profile due to continuous mechanical and biochemical defense mechanisms.The conjunctival surface hosts fewer microbial... https://www.jove.com/v/40793 82 2026-03-12T20:35:56+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61749.jpg Intravitreal Injection and Quantitation of Infection Parameters in a Mouse Model of Bacterial Endophthalmitis We describe here a method of intravitreal injection and subsequent bacterial quantitation in mouse model of bacterial endophthalmitis. This protocol can be extended for measuring host immune responses and bacterial and host gene expression. https://www.jove.com/v/61749 444 2021-02-06T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62925.jpg Primed Mycobacterial Uveitis (PMU) as a Model for Post-Infectious Uveitis This protocol outlines the steps for inducing Primed Mycobacterial Uveitis (PMU) in mice. This method outlines the steps to help produce reliable and robust ocular inflammation in the mouse model system. Using this protocol, we generated uveitic eyes and uninflamed fellow eyes from single animals for further evaluation with immunologic, transcriptomic, and proteomic assays. https://www.jove.com/v/62925 633 2021-12-17T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66662.jpg Intracameral Injection in Rats with Low Risk of Adverse Effects This protocol describes a technique for intracameral injection in rats using a central corneal incision and a long tunnel into the anterior chamber. This injection method minimizes the risk of inducing inadvertent tissue damage and thereby improves precision and reproducibility. https://www.jove.com/v/66662 379 2024-05-31T21:10:00+00:00 JoVE no https://visualize.jove.com/3831215-chromosome-replication-in-early-development-of-xenopus-laevis monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10789.jpg Replication in Eukaryotes Overview In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus. Many Proteins Orchestrate Replication at the Origin Eukaryotic replication follows many of the... https://www.jove.com/v/10789 151 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11529.jpg Chromosome Structure A functional eukaryotic chromosome must contain three elements: a centromere, telomeres, and numerous origins of replication. The centromere is a DNA sequence that links sister chromatids. This is also where kinetochores, protein complexes to which spindle microtubules attach, are constructed after the chromosome is replicated. The kinetochores allow the spindle microtubules to move the chromosomes within the cell during cell division. Telomeres consist of non-coding repetitive nucleotide... https://www.jove.com/v/11529 160 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11530.jpg Chromosome Replication Before a cell can divide, it must accurately replicate all of its chromosomes, including the DNA and its associated histone and non-histone proteins. This process begins at numerous origins of replication during the S phase of the cell cycle in each of a cell’s chromosomes simultaneously. Certain nucleotides can act as origins of replication, but these sequences are not well defined - especially in complex, multi-cellular, eukaryotic species. The length of DNA that spans an origin of... https://www.jove.com/v/11530 151 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11539.jpg Lampbrush Chromosomes In 1882, Flemming observed lampbrush chromosomes (LBC) in salamander eggs. Later in 1892, Rückert observed LBCs in shark egg cells and coined the term "lampbrush chromosomes" because they looked like brushes used to clean kerosene lamps. LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops resemble the... https://www.jove.com/v/11539 111 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11539.jpg Lampbrush Chromosomes In 1882, Flemming observed lampbrush chromosomes (LBC) in salamander eggs. Later in 1892, Rückert observed LBCs in shark egg cells and coined the term "lampbrush chromosomes" because they looked like brushes used to clean kerosene lamps. LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops resemble the... https://www.jove.com/v/13188 111 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13196.jpg Replication in Eukaryotes In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fulfill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus. Many Proteins Orchestrate Replication at the Origin Eukaryotic replication follows many of the same... https://www.jove.com/v/13196 89 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52496.jpg Manipulation and In Vitro Maturation of Xenopus laevis Oocytes, Followed by Intracytoplasmic Sperm Injection, to Study Embryonic Development We describe methods of manipulating Xenopus laevis immature oocytes, in vitro maturation of oocytes to eggs, and intracytoplasmic sperm injection. This protocol allows degradation of some maternal proteins and overexpression of genes of interest at fertilization, and hence is valuable to study roles of specific factors in early embryonic development. https://www.jove.com/v/52496 562 2015-02-09T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52535.jpg Genome-wide Snapshot of Chromatin Regulators and States in Xenopus Embryos by ChIP-Seq The question of how chromatin regulators and chromatin states affect the genome in vivo is key to our understanding of how early cell fate decisions are made in the developing embryo. ChIP-Seq—the most popular approach to investigate chromatin features at a global level—is outlined here for Xenopus embryos. https://www.jove.com/v/52535 623 2015-02-26T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/70602.jpg Physical Manipulation to Generate Xenopus Mini Embryos We describe a physical constriction method to make mini embryos from Xenopus laevis 1-cell embryos. https://www.jove.com/v/70602 249 2026-04-10T20:20:00+00:00 JoVE no https://visualize.jove.com/3838278-nucleotide-sequences-of-the-cdna-and-an-intronless-pseudogene-for-human-lactate-dehydrogenase-a-isozyme monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1543.jpg Dissection of Hippocampal Dentate Gyrus from Adult Mouse A dissection technique for removal of the dentate gyrus from adult mouse under a stereomicroscope was demonstrated in this video-recorded protocol. https://www.jove.com/v/1543 462 2009-11-18T04:30:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10984.jpg Operons Prokaryotes can control gene expression through operons—DNA sequences consisting of regulatory elements and clustered, functionally related protein-coding genes. Operons use a single promoter sequence to initiate transcription of a gene cluster (i.e., a group of structural genes) into a single mRNA molecule. The terminator sequence ends transcription. An operator sequence, located between the promoter and structural genes, prohibits the operon’s transcriptional activity if bound by a repressor... https://www.jove.com/v/10984 129 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11574.jpg Non-LTR Retrotransposons As the name suggests, non-LTR retrotransposons lack the long terminal repeats characteristic of the LTR retrotransposons. Additionally, both LTR and non-LTR retrotransposons use distinct mechanisms of mobilization. Non-LTR retrotransposons are further divided into two classes - Long interspersed nuclear elements (LINEs) and short interspersed nuclear elements (SINEs), both of which occur abundantly in most mammals, including humans. Some of the active non-LTR retrotransposons in humans are L1... https://www.jove.com/v/11574 198 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11605.jpg Cell Specific Gene Expression Multicellular organisms contain a variety of structurally and functionally distinct cell types, but the DNA in all the cells originated from the same parent cells. The differences in the cells can be attributed to the differential gene expression. Liver cells, whose functions include detoxification of blood, production of bile to metabolize fats, and synthesis of proteins essential for metabolism, must express a specific set of genes to perform their functions. Gene expression also varies with... https://www.jove.com/v/11605 118 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11632.jpg lncRNA - Long Non-coding RNAs In humans, more than 80% of the genome gets transcribed. However, only around 2% of the genome codes for proteins. The remaining part produces non-coding RNAs which includes ribosomal RNAs, transfer RNAs, telomerase RNAs, and regulatory RNAs, among other types. A large number of regulatory non-coding RNAs have been classified into two groups depending upon their length – small non-coding RNAs, such as microRNA, which are less than 200 nucleotides in length, and long non-coding RNA (lncRNA)... https://www.jove.com/v/11632 159 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11993.jpg Exon Recombination The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes. Exon shuffling follows “splice frame rules.” Each exon has three reading... https://www.jove.com/v/11993 152 JoVE no https://cloudfront.jove.com/files/ftp_upload/19533/19533_article_thumb_19533.jpg Inducible Operons: lac Operon The lac operon in Escherichia coli is a model for understanding inducible gene regulation and metabolic flexibility. It integrates local control by lactose and global regulation through catabolite repression, enabling E. coli to preferentially metabolize glucose when available and switch to lactose utilization when glucose is scarce.Structure and Function of the lac OperonThe lac operon contains three structural genes: lacZ (β-galactosidase), lacY (lactose permease), and lacA (thiogalactoside... https://www.jove.com/v/19533 85 2025-06-12T16:14:20+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57510.jpg The Lambda Select cII Mutation Detection System We describe a detailed protocol for the Lambda Select cII mutation assay in cultured cells of transgenic rodents or the corresponding animals treated with a chemical/physical agent of interest. This approach has been widely used for mutagenicity testing of carcinogens in mammalian cells. https://www.jove.com/v/57510 428 2018-04-26T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57760.jpg Mapping Metabolism: Monitoring Lactate Dehydrogenase Activity Directly in Tissue We describe a protocol for mapping the spatial distribution of enzymatic activity for enzymes that generate nicotinatmide adenine dinucleotide phosphate (NAD(P)H) + H+ directly in tissue samples. https://www.jove.com/v/57760 378 2018-06-21T21:00:00+00:00 JoVE no https://visualize.jove.com/3934672-expression-of-rat-apolipoprotein-a-iv-and-a-i-genes-mrna-induction-during-development-and-in-response-to-glucocorticoids-and-insulin monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4080.jpg Assessing Replication and Beta Cell Function in Adenovirally-transduced Isolated Rodent Islets This protocol allows one to identify factors that modulate functional beta cell mass to find potential therapeutic targets for the treatment of diabetes. The protocol consists of a streamlined method to assess islet replication and beta cell function in isolated rat islets following manipulation of gene expression with adenoviruses. https://www.jove.com/v/4080 571 2012-06-25T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11605.jpg Cell Specific Gene Expression Multicellular organisms contain a variety of structurally and functionally distinct cell types, but the DNA in all the cells originated from the same parent cells. The differences in the cells can be attributed to the differential gene expression. Liver cells, whose functions include detoxification of blood, production of bile to metabolize fats, and synthesis of proteins essential for metabolism, must express a specific set of genes to perform their functions. Gene expression also varies with... https://www.jove.com/v/11605 118 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12220.jpg Insulin Secretory Vesicles Insulin secretory vesicles release insulin to stimulate blood glucose uptake and regulate carbohydrate metabolism. When the blood glucose levels increase, glucose enters the pancreatic β-islet cells through glucose transporters. Once inside, glucose is metabolized through glycolysis, the citric acid cycle, and the electron transport chain, producing ATP. This increase in ATP concentration closes ATP-sensitive potassium channels, leading to depolarization of the membrane and the opening of... https://www.jove.com/v/12220 65 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17293.jpg Insulin: The Receptor and Signaling Pathways Insulin action is mediated through a receptor tyrosine kinase, akin to the IGF-1 receptor. The number of receptors per cell varies significantly, from 40 on erythrocytes to 300,000 on adipocytes and hepatocytes. The insulin receptor consists of linked α/β subunit dimers, forming a heterotetramer glycoprotein with two extracellular α subunits and two β subunits spanning the membrane. The α subunits inhibit the inherent tyrosine kinase activity of the β subunits, but this inhibition is released... https://www.jove.com/v/17293 88 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62332.jpg Isolating Brown Adipocytes from Murine Interscapular Brown Adipose Tissue for Gene and Protein Expression Analysis This study describes a new method of isolating murine brown adipocytes for gene and protein expression analysis. https://www.jove.com/v/62332 427 2021-03-12T22:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68677.jpg Precise Visualization of Insulin Receptors A and B in Murine Brain with an RNA In Situ Hybridization Assay We established a Duplex in situ hybridization assay to map insulin receptor isoforms IR-A and IR-B in the murine choroid plexus, overcoming limitations of traditional methods. This high-resolution approach reveals isoform-specific expression, offering new insights into brain insulin signaling and potential isoform-targeted therapies for neurological disorders. https://www.jove.com/v/68677 514 2025-07-15T21:00:00+00:00 JoVE no https://visualize.jove.com/3936527-an-evaluation-of-the-accuracy-of-pharmacokinetic-data-for-the-computer-assisted-infusion-of-alfentanil monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16573.jpg One-Compartment Model: IV Infusion Intravenous (IV) infusion is often utilized when continuous and controlled drug delivery is necessary, such as during surgery or in the treatment of chronic diseases. This method offers numerous advantages, including immediate drug action, precise control over dosage, and bypassing the first-pass metabolism. The one-compartment model for IV infusion uses mathematical equations to describe the rate of change in drug quantity in the body. At steady-state or infusion equilibrium, the drug input... https://www.jove.com/v/16573 69 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16576.jpg One-Compartment Open Model: Wagner-Nelson and Loo Riegelman Method for k a Estimation This lesson introduces two critical methods in pharmacokinetics, the Wagner-Nelson and Loo-Riegelman methods, used for estimating the absorption rate constant (ka) for drugs administered via non-intravenous routes. The Wagner-Nelson method relates ka to the plasma concentration derived from the slope of a semilog percent unabsorbed time plot. However, it is limited to drugs with one-compartment kinetics and can be impacted by factors like gastrointestinal motility or enzymatic degradation. On... https://www.jove.com/v/16576 84 JoVE no https://cloudfront.jove.com/files/ftp_upload/17147/17147_article_thumb_17147.jpg Measurement of Bioavailability: Pharmacokinetic Methods Pharmacokinetics is a vital branch of pharmacology that examines how drugs are absorbed, distributed, metabolized, and excreted by the body. Two key methodologies in pharmacokinetics are plasma drug concentration studies and urinary drug excretion analyses, both of which provide critical insights into a drug's therapeutic efficacy and bioavailability.Plasma Drug Concentration-Time StudiesPlasma drug concentration-time studies involve analyzing blood samples at specific intervals to quantify... https://www.jove.com/v/17147 90 2025-10-03T14:00:41+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17176/17176_article_thumb_17176.jpg Dosage Regimens: Partial Pharmacokinetic Parameters It is not uncommon for complete drug pharmacokinetic profiles to remain elusive in pharmacokinetics. This necessitates certain educated assumptions by pharmacokineticists to determine appropriate dosage regimens without comprehensive pharmacokinetic data from animal or human studies. One prevalent assumption is setting the bioavailability factor, denoted as F, to 1 or 100%. This assumption caters to the scenario where a drug doesn't achieve full systemic absorption, resulting in the patient... https://www.jove.com/v/17176 61 2025-10-03T14:00:30+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17183/17183_article_thumb_17183.jpg Drug Accumulation During Multiple Dosing: Intermittent IV Infusions Intermittent intravenous (IV) infusion is a method of drug administration where medications are delivered over short infusion periods followed by intervals of no drug delivery. This approach helps to prevent sustained high drug concentrations in the bloodstream, reducing the risk of adverse effects associated with prolonged exposure. Unlike continuous infusion, steady-state concentrations may not be achieved during a single dosing cycle but can be reached through repeated... https://www.jove.com/v/17183 84 2025-10-03T14:00:28+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17184/17184_article_thumb_17184.jpg Determination of Multiple Dosing Parameters: Steady-State, Minimum and Maximum Concentrations Gentamicin, an aminoglycoside antibiotic, is commonly administered via intermittent intravenous infusion to treat severe infections. An intermittent one-hour infusion of gentamicin, administered at eight-hour intervals, allows for precise control of plasma drug concentrations, minimizing toxicity while ensuring therapeutic efficacy. Pharmacokinetic principles govern the dynamics of plasma concentrations and can be mathematically described using specific equations.The plasma drug concentration... https://www.jove.com/v/17184 75 2025-12-03T21:40:18+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55086.jpg Evaluation of Drug Sorption to PVC- and Non-PVC-based Tubes in Administration Sets Using a Pump We report a method for drug sorption evaluation using a pump and model drugs (diazepam and tacrolimus). After drug analysis using high-performance liquid chromatography, drug concentrations and sorption levels in the tubes of administration sets are calculated. https://www.jove.com/v/55086 368 2017-03-11T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59701.jpg Continuous Blood Sampling in Small Animal Positron Emission Tomography/Computed Tomography Enables the Measurement of the Arterial Input Function Here a protocol for continuous blood sampling during PET/CT imaging of rats to measure the arterial input function (AIF) is described. The catheterization, the calibration and setup of the system and the data analysis of the blood radioactivity are demonstrated. The generated data provide input parameters for subsequent bio-kinetic modeling. https://www.jove.com/v/59701 621 2019-08-08T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60184.jpg An Intestine/Liver Microphysiological System for Drug Pharmacokinetic and Toxicological Assessment We exposed a microphysiological system (MPS) with intestine and liver organoids to acetaminophen (APAP). This article describes the methods for organoid production and APAP pharmacokinetic and toxicological property assessments in the MPS. It also describes the tissue functionality analyses necessary to validate the results. https://www.jove.com/v/60184 539 2020-12-03T20:30:00+00:00 JoVE no https://visualize.jove.com/3959844-improvement-in-radionuclide-imaging-of-the-adrenals monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4240.jpg Non-invasive Imaging of Acute Allograft Rejection after Rat Renal Transplantation Using 18 F-FDG PET We herein present a rat renal transplantation model to non-invasively assess acute allograft rejection using positron emission tomography with 18F-fluorodeoxyglucose. https://www.jove.com/v/4240 1033 2013-04-28T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16374.jpg Radiological Investigation I: X-ray and CT Radiological investigations, including X-rays and computed tomography (CT) scans, are critical for diagnosing and evaluating various medical conditions. These imaging techniques provide valuable insights into the body's internal structures, aiding in the detection of abnormalities, assessment of disease progression, and development of treatment strategies. This article delves into two primary radiological investigations, chest X-rays and CT scans, outlining their purpose, procedures, and the... https://www.jove.com/v/16374 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16376.jpg Radiological Investigation III: Pulmonary Angiogram and PET Scan Radiological investigations are paramount in the diagnosis and management of various pulmonary diseases. Two essential investigations are the Pulmonary Angiogram and the Positron Emission Tomography (PET) Scan. Pulmonary Angiogram A Pulmonary Angiogram is an invasive procedure involving injecting a contrast medium through a catheter threaded into the pulmonary artery or the right side of the heart to visualize the pulmonary vasculature. Computed Tomography (CT) scans have mainly replaced this... https://www.jove.com/v/16376 73 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16449.jpg Imaging Studies II: Positron Emission Tomography and Scintigraphy Positron Emission Tomography (PET) is a medical imaging technique that provides crucial insights into the body's physiological functions at a molecular level. It is an indispensable resource for diagnosing, staging, and monitoring various illnesses, notably cancer, neurological disorders, and cardiovascular conditions. Fundamental Principles of PET Radioactive Tracer: PET involves using biologically active molecules labeled with radioactive isotopes, known as tracers or radiotracers. The... https://www.jove.com/v/16449 85 JoVE no https://cloudfront.jove.com/files/ftp_upload/18490/18490_article_thumb_18490.jpg Imaging Studies III: Computed Tomography DefinitionComputed Tomography (CT) of the genitourinary (GU) tract is a non-invasive imaging modality that utilizes X-rays and computer processing to generate detailed cross-sectional images of the urinary system, encompassing the kidneys, ureters, bladder, and adjacent structures such as the adrenal glands.PurposeCT scans of the GU tract serve several diagnostic and therapeutic purposes, including:Diagnosis of Urinary Tract Diseases: Detects kidney stones, tumors, cysts, and congenital... https://www.jove.com/v/18490 87 2025-06-19T16:29:40+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18491/18491_article_thumb_18491.jpg Imaging Studies IV: Magnetic Resonance Imaging Introduction:Magnetic Resonance Imaging, or MRI, can include a specialized imaging technique of the urinary system known as Magnetic Resonance Urography (MRU). This radiation-free technique uses strong magnetic fields and radio waves to produce detailed images with the help of a computer. MRU is particularly effective for visualizing fluid-filled structures like the kidneys, ureters, and bladder.Applications of MRI in the Genitourinary SystemKidneys and Ureters: MRI detects tumors, cysts,... https://www.jove.com/v/18491 87 2025-06-19T16:29:57+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18494/18494_article_thumb_18494.jpg Imaging Studies VII: Vascular Imaging DefinitionRenal angiography, also known as renal arteriography, is an imaging technique used to obtain a comprehensive view of blood flow and the vascular structure of blood vessels in the kidneys and surrounding areas.PurposeRenal angiography detects blood vessel abnormalities in the kidneys, such as aneurysms, stenosis, thrombosis, vascular tumors, and renal artery stenosis. It evaluates kidney function and guides interventional treatments like angioplasty or stent placement.Pre-Procedure... https://www.jove.com/v/18494 79 2025-06-19T16:30:31+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60477.jpg A Whole Body Dosimetry Protocol for Peptide-Receptor Radionuclide Therapy (PRRT): 2D Planar Image and Hybrid 2D+3D SPECT/CT Image Methods This method estimates the absorbed dose of different structures for peptide-receptor-radionuclide-therapy (PRRT) with the possibility of avoiding organ overlap on 2D-projections. Serial whole-body planar images permit estimation of mean absorbed doses along the whole body, while the hybrid approach, combining planar images and 3D-SPECT/CT image, overcomes the limitations of structure overlapping. https://www.jove.com/v/60477 589 2020-04-24T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67048.jpg Radiosynthesis, Quality Control, and Small Animal Positron Emission Tomography Imaging of 68 Ga-Labelled Nano Molecules This paper describes the radiosynthesis, formulation, quality control of a new radiolabeled probe (i.e., 68Ga-labeled nanobody NM-02), and its use for small animal PET/CT imaging in a xenograft model. https://www.jove.com/v/67048 595 2024-10-04T21:15:00+00:00 JoVE no https://visualize.jove.com/3972505-predicting-refractive-alterations-with-hydrogel-keratophakia monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/58590.jpg Synthesis of Soft Polysiloxane-urea Elastomers for Intraocular Lens Application This study describes synthetic routes for aminopropyl-terminated polydimethylsiloxanes and polydimethyl-methyl-phenyl-siloxane-block copolymers and for soft polysiloxane-based urea (PSU) elastomers. It presents the application of PSUs as accommodating an intraocular lens. An evaluation method for in vitro cytotoxicity is also described. https://www.jove.com/v/58590 709 2019-03-08T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67173.jpg Correction of Presbyopia by Monocular Bi-Aspheric Ablation Profile This article provides a step-by-step guide to correcting presbyopia with a monocular bi-aspheric ablation profile. https://www.jove.com/v/67173 346 2024-09-20T20:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68422.jpg Comparison of Agreement and Accuracy using Binocular Wavefront Optometer with Autorefractor and Phoropter The binocular wavefront optometer agrees well with traditional refraction techniques in both objective and subjective refraction measurements, offering superior accuracy and clinical utility. Its standardized protocol reduces optometrist workload and provides a more accurate refractive assessment for post-refractive surgery individuals. https://www.jove.com/v/68422 314 2025-09-16T19:30:00+00:00 JoVE no https://visualize.jove.com/3990797-alpha-interferon-induced-transcription-of-hla-and-metallothionein-genes-containing-homologous-upstream-sequences monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10983.jpg Transcription Factors Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of... https://www.jove.com/v/10983 136 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11584.jpg RNA Polymerase II Accessory Proteins Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in... https://www.jove.com/v/11584 156 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11617.jpg Master Transcription Regulators Master transcription regulators are regulatory proteins that are predominantly responsible for regulating the expression of multiple genes. Often these genes work in concert to drive a complex process. Activation of a master transcription regulator can lead to a cascade of transcriptional activation necessary for that outcome. These regulators can directly bind to the regulatory sequences of the various genes involved, or they can indirectly regulate transcription by binding to regulatory... https://www.jove.com/v/11617 143 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11625.jpg Leaky Scanning During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R stands for... https://www.jove.com/v/11625 148 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11993.jpg Exon Recombination The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes. Exon shuffling follows “splice frame rules.” Each exon has three reading... https://www.jove.com/v/11993 152 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12561.jpg General Transcription Factors Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of... https://www.jove.com/v/12561 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52650.jpg High-throughput Quantitative Real-time RT-PCR Assay for Determining Expression Profiles of Types I and III Interferon Subtypes This protocol describes a high-throughput qRT-PCR assay for the analysis of type I and III IFN expression signatures. The assay discriminates single base pair differences between the highly similar transcripts of these genes. Through batch assembly and robotic pipetting, the assays are consistent and reproducible. https://www.jove.com/v/52650 600 2015-03-24T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55135.jpg Genome-wide Analysis of HDAC Inhibitor-mediated Modulation of microRNAs and mRNAs in B Cells Induced to Undergo Class-switch DNA Recombination and Plasma Cell Differentiation Epigenetic factors can interact with genetic programs to modulate gene expression and regulate B cell function. By combining in vitro B-cell stimulation, qRT-PCR, and high-throughput microRNA-sequence and mRNA-sequence approaches, we can analyze the epigenetic modulation of miRNA and gene expression in B cells. https://www.jove.com/v/55135 666 2017-09-20T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56278.jpg Personalized Peptide Arrays for Detection of HLA Alloantibodies in Organ Transplantation Mismatches in human leukocyte antigen (HLA) sequences between organ donor and recipient pairs are the major cause of antibody-mediated rejection in organ transplantation. Here we present the use of custom antigen arrays that are based on individual donors' HLA sequences to probe anti-donor HLA alloantibodies in organ recipients. https://www.jove.com/v/56278 487 2017-09-06T22:00:00+00:00 JoVE no https://visualize.jove.com/4024050-interactions-between-sodium-salicylate-and-acetyl-salicylic-acid-evaluated-using-adp-induced-platelet-aggregation-and-bleeding-time monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15041.jpg Antiplatelet Drugs: Prostaglandin Synthesis, P2Y12 and Glycoprotein IIb/IIIa Inhibitors Antiplatelet drugs emerge as frontline defenders against the insidious threat of thromboembolic diseases, where abnormal clots obstruct vital blood vessels. These drugs stand as bulwarks, inhibiting platelet aggregation and clot formation, thereby mitigating the risk of life-threatening conditions like myocardial infarction, coronary artery disease, and thrombotic strokes. Prostaglandin synthesis inhibitors, exemplified by the widely known aspirin, wield their power by irreversibly acetylating... https://www.jove.com/v/15041 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15255.jpg Formation of the Platelet Plug The platelet phase, the second stage of hemostasis, commences around 15-20 seconds after an injury. It follows and overlaps with the vascular phase, during which blood vessels constrict to minimize blood loss. As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets... https://www.jove.com/v/15255 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16472.jpg Structure-Activity Relationships and Drug Design Drug design is a dynamic field that involves discovering and developing new medications based on specific biological targets. This process heavily relies on structure-activity relationships (SAR) and quantitative structure-activity relationships (QSAR) to guide the design and optimization of efficient drugs. SAR studies the intricate relationship between a drug's chemical structure and biological activity. It focuses on understanding how modifications to a drug's structure can influence its... https://www.jove.com/v/16472 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16536.jpg Phase II Reactions: Sulfation and Conjugation with α-Amino Acids Sulfation and α-amino acid conjugation are two critical biotransformation reactions in drug metabolism. Sulfation, a phase II biotransformation reaction, involves adding a polar sulfate group to a drug, enhancing its water solubility and promoting excretion. This process can either co-occur with or occur independently of glucuronidation. Nonmicrosomal sulfotransferase enzymes catalyze the process. The reaction involves 3'-phosphoadenosine-5'-phosphosulfate or PAPS coenzyme activation, sulfur... https://www.jove.com/v/16536 79 JoVE no https://cloudfront.jove.com/files/ftp_upload/17191/17191_article_thumb_17191.jpg Pharmacokinetics: Drug–Drug Interactions Drug interactions occur when the pharmacological effect of one drug is altered by another substance, either enhancing or diminishing its activity. The drug whose activity is altered is known as the object drug, and the substance causing the alteration is called the agent drug or the precipitant. The net effects of these interactions are mostly undesirable, leading to decreased effectiveness or increased adverse effects. In rare cases, interactions can be beneficial, such as the enhanced... https://www.jove.com/v/17191 85 2025-10-03T14:00:18+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17269/17269_article_thumb_17269.jpg Drug toxicity: Drug–Drug Interaction Drug–drug interactions can precipitate toxicity through multiple mechanisms. Absorption interactions alter how drugs enter the body, exemplified when ranitidine increases the absorption of basic drugs, while cholestyramine decreases the levels of propranolol. Protein binding interactions occur when drugs share the same binding sites on plasma proteins. Drugs like aspirin and warfarin, when bound in excess, can lead to increased free drug concentrations, enhancing the potential for... https://www.jove.com/v/17269 90 2026-02-12T19:16:59+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66783.jpg Dynamic Multiparameter Platelet Function Assessment Using a Capacitive Biosensor A protocol for a novel dynamic multiparameter platelet functional assay using a capacitive biosensor is presented here. This approach, designed within a semi-rigid microenvironment to enhance physiological relevance, provides three output parameters sensitive to platelet count, stimulation strengths, and activation pathways. https://www.jove.com/v/66783 392 2025-05-02T19:40:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67214.jpg Microfluidics in Assessing Platelet Function Platelet function under flow can be assessed and simulated hemostatic resuscitation can be modeled using a microfluidic device, which has applications in trauma and transfusion medicine. https://www.jove.com/v/67214 407 2024-11-08T22:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68116.jpg Comprehensive Analysis of Procoagulant Platelets Exhibiting Features of Necrosis, Apoptosis and Platelet Activation The present protocol provides a comprehensive set of procedures necessary to analyze procoagulant platelets, which exhibit overlapping features of necrosis, apoptosis, and platelet activation. https://www.jove.com/v/68116 277 2025-05-23T21:00:00+00:00 JoVE no https://visualize.jove.com/4027277-formal-model-of-the-generation-of-alpha-rhythm-of-human-electroencephalograms-based-on-principles-of-statistical-dynamics monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14942.jpg Brain Waves Brain waves are electrical signals generated by the neurons in the brain, which are regularly monitored to measure mental activities. Brain waves and their frequency ranges can be measured using an electroencephalogram or EEG. There are four main types of brain waves, each with distinct characteristics: • Alpha Waves – Alpha brain waves, between 8 and 13 Hz ( Hertz), occur when a person is relaxed with eyes closed. The alpha waves then disappear when one is concentrating on specific tasks. <br... https://www.jove.com/v/14942 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51412.jpg EEG Mu Rhythm in Typical and Atypical Development Assessment of the EEG mu rhythm provides a unique methodology for examining brain activity and when combined with behaviorally based assays, can be a powerful tool for elucidating aspects of social cognition, such as imitation, in clinical populations. https://www.jove.com/v/51412 710 2014-04-10T05:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55089.jpg Automatic Detection of Highly Organized Theta Oscillations in the Murine EEG Theta activity in the hippocampus is related to specific cognitive and behavioral stages. Here, we describe an analytical method to detect highly-organized theta oscillations within the hippocampus using a time-frequency (i.e., wavelet analysis)-based approach. https://www.jove.com/v/55089 575 2017-03-10T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65829.jpg BrainBeats as an Open-Source EEGLAB Plugin to Jointly Analyze EEG and Cardiovascular Signals The BrainBeats toolbox is an open-source EEGLAB plugin designed to jointly analyze EEG and cardiovascular (ECG/PPG) signals. It includes heartbeat-evoked potentials (HEP) assessment, feature-based analysis, and heart artifact extraction from EEG signals. The protocol will aid in studying brain-heart interplay through two lenses (HEP and features), enhancing reproducibility and accessibility. https://www.jove.com/v/65829 502 2024-04-26T19:40:00+00:00 JoVE no https://visualize.jove.com/4052472-development-of-a-model-of-normal-human-alpha-rhythm-from-empirical-data monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14942.jpg Brain Waves Brain waves are electrical signals generated by the neurons in the brain, which are regularly monitored to measure mental activities. Brain waves and their frequency ranges can be measured using an electroencephalogram or EEG. There are four main types of brain waves, each with distinct characteristics: • Alpha Waves – Alpha brain waves, between 8 and 13 Hz ( Hertz), occur when a person is relaxed with eyes closed. The alpha waves then disappear when one is concentrating on specific tasks. <br... https://www.jove.com/v/14942 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15027.jpg Electrophysiology of Normal Cardiac Rhythm The normal cardiac rhythm is a synchronized electrical activity that facilitates the regular and coordinated contraction of the heart muscle. This process is essential for efficient blood circulation throughout the body. The fundamental elements involved in establishing and maintaining this rhythm include the unique electrical properties of cardiac muscle cells, the sinoatrial (SA) node's pacemaker function, the specialized conducting system, and the ionic mechanisms underlying each phase of... https://www.jove.com/v/15027 79 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51412.jpg EEG Mu Rhythm in Typical and Atypical Development Assessment of the EEG mu rhythm provides a unique methodology for examining brain activity and when combined with behaviorally based assays, can be a powerful tool for elucidating aspects of social cognition, such as imitation, in clinical populations. https://www.jove.com/v/51412 710 2014-04-10T05:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52420.jpg Infant Auditory Processing and Event-related Brain Oscillations High-density electroencephalography (dEEG) is being used increasingly to study brain development and plasticity in the early years of life. Here we present an application of sophisticated analysis techniques that builds on traditional EEG recording to understand the oscillatory dynamics of rapid auditory processing in the infant brain. https://www.jove.com/v/52420 394 2015-07-01T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55089.jpg Automatic Detection of Highly Organized Theta Oscillations in the Murine EEG Theta activity in the hippocampus is related to specific cognitive and behavioral stages. Here, we describe an analytical method to detect highly-organized theta oscillations within the hippocampus using a time-frequency (i.e., wavelet analysis)-based approach. https://www.jove.com/v/55089 575 2017-03-10T21:00:00+00:00 JoVE no https://visualize.jove.com/4066751-alpha-tubulin-acetylase-activity-in-isolated-chlamydomonas-flagella monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/58109.jpg Isolation and Fluorescence Imaging for Single-particle Reconstruction of Chlamydomonas Centrioles We have developed a strategy to purify and image a large number of centrioles in different orientations amenable for super-resolution microscopy and single-particle averaging. https://www.jove.com/v/58109 638 2018-09-21T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63869.jpg Reactivation of Demembranated Cell Models in Chlamydomonas reinhardtii The in vitro reactivation of motile cells is a crucial experiment in understanding the mechanisms of cell motility. The protocol describes reactivating the demembranated cell models of Chlamydomonas reinhardtii, a model organism to study cilia/flagella. https://www.jove.com/v/63869 217 2022-05-06T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63961.jpg Observation of Photobehavior in Chlamydomonas reinhardtii Most swimming photoautotrophic organisms show photo-induced behavioral changes (photobehavior). The present protocol observes the said photobehavior in the model organism Chlamydomonas reinhardtii. https://www.jove.com/v/63961 234 2022-05-06T22:00:00+00:00 JoVE no https://visualize.jove.com/4075137-physiological-evidence-for-an-excitatory-pathway-from-entorhinal-cortex-to-amygdala-in-the-rat monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3802.jpg Preparation of Parasagittal Slices for the Investigation of Dorsal-ventral Organization of the Rodent Medial Entorhinal Cortex We describe procedures for preparation and electrophysiological recording from brain slices that maintain the dorsal-ventral axis of the medial entorhinal cortex (MEC). Because neural encoding of location follows a dorsal-ventral organization within the MEC, these procedures facilitate investigation of cellular mechanisms important for navigation and memory. https://www.jove.com/v/3802 585 2012-03-28T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14915.jpg Functional Brain Systems: Limbic System The limbic system, often called the "emotional brain," is a complex set of structures located deep within the brain. The intricate network of the limbic system supports a wide range of psychological functions, from emotional regulation to memory formation and sensory processing. This functional brain region encompasses specific parts of the diencephalon and the cerebrum, integrating the higher mental functions of the cerebral cortex with the primitive emotional responses of the deep brain... https://www.jove.com/v/14915 75 2025-06-13T16:15:56+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18185.jpg Role of Amygdala in Memory The amygdala is a small, almond-shaped structure responsible for processing and storing memories, particularly those linked to emotions like fear and stress. It plays an essential role in the brain's response to emotionally significant events and often enhances memory formation by triggering stress hormone release. The amygdala is vital for encoding and retrieving memories associated with fear or stress, a process that is adaptive by helping organisms avoid dangerous situations. One of the... https://www.jove.com/v/18185 76 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53628.jpg Ex Vivo Optogenetic Dissection of Fear Circuits in Brain Slices Optogenetic approaches are widely used to manipulate neural activity and assess the consequences for brain function. Here, a technique is outlined that upon in vivo expression of the optical activator Channelrhodopsin, allows for ex vivo analysis of synaptic properties of specific long range and local neural connections in fear-related circuits. https://www.jove.com/v/53628 673 2016-04-06T00:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53853.jpg Combined Optogenetic and Freeze-fracture Replica Immunolabeling to Examine Input-specific Arrangement of Glutamate Receptors in the Mouse Amygdala This article illustrates how the expression of neurotransmitter receptors can be quantified and the pattern analyzed at synapses with identified pre and postsynaptic elements using a combination of viral transduction of optogenetic tools and the freeze-fracture replica immunolabeling technique. https://www.jove.com/v/53853 589 2016-04-15T22:00:00+00:00 JoVE no https://visualize.jove.com/4092369-continuous-24-hour-intra-arterial-blood-pressure-recording-in-the-conscious-unrestrained-rabbit monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/54120.jpg Novel Approach for Simultaneous Recording of Renal Sympathetic Nerve Activity and Blood Pressure with Intravenous Infusion in Conscious, Unrestrained Mice. Anesthetized mice exhibit non-physiological systemic blood pressure, which precludes meaningful assessment of autonomic tone given the intimate relationship between blood pressure and the autonomic nervous system. Thus, a novel method to simultaneously record renal sympathetic nerve activity and blood pressure with intravenous infusion in conscious mice is outlined. https://www.jove.com/v/54120 668 2018-02-14T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59115.jpg Simultaneous Electrocardiography Recording and Invasive Blood Pressure Measurement in Rats Here, we describe a setup for simultaneous recording of electrocardiography and intra-arterial blood pressure (BP) in experimental rats, which can be done with standard equipment in animal facilities and can be applied to physiological or pharmacological studies to investigate pathogenic or therapeutic mechanisms in cardiovascular medicine. https://www.jove.com/v/59115 455 2019-01-31T22:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64672.jpg Real-Time Monitoring and Modulation of Blood Pressure in a Rabbit Model of Ischemic Stroke Continuous arterial blood pressure recording allows the investigation of impacts of various hemodynamic parameters. This report demonstrates the application of continuous arterial blood pressure monitoring in a large animal model of ischemic stroke for determination of stroke pathophysiology, impact of different hemodynamic factors, and the assessment of novel treatment approaches. https://www.jove.com/v/64672 540 2023-02-10T21:15:00+00:00 JoVE no https://visualize.jove.com/4588197-evaluation-of-the-pathotec-rapid-i-d-system-and-two-additional-experimental-reagent-impregnated-paper-strips monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40815/40815_article_thumb_40815.jpg Rapid Identification of Pathogens MALDI-TOF MS has transformed clinical microbiology by offering a rapid and reliable method for pathogen identification. The traditional approach to microbial identification typically involves time-consuming culture techniques and biochemical tests, which can delay the initiation of appropriate antimicrobial therapy. MALDI-TOF MS avoids these delays by using characteristic ribosomal protein mass patterns of microbial cells, enabling accurate species-level identification within minutes.Principle... https://www.jove.com/v/40815 85 2026-05-20T20:51:01+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40816/40816_article_thumb_40816.jpg Automated Microbial Diagnostics Automated diagnostic analyzers have transformed clinical microbiology by providing rapid and reliable methods for pathogen identification and antibiotic susceptibility testing. Among these systems, the Vitek 2 is widely used because it automates the traditionally labor-intensive processes of microbial identification (ID) and antibiotic susceptibility testing (AST), delivering standardized and timely results that are essential for effective patient care.Microbial Identification with ID CardsThe... https://www.jove.com/v/40816 84 2026-03-12T20:35:56+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60008.jpg Field Postmortem Rabies Rapid Immunochromatographic Diagnostic Test for Resource-Limited Settings with Further Molecular Applications We present a complete protocol for postmortem diagnosis of animal rabies under field conditions using a rapid immunochromatographic diagnostic test (RIDT), from brain biopsy sampling to final interpretation. We also describe further applications using the device for molecular analysis and viral genotyping. https://www.jove.com/v/60008 460 2020-06-29T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62754.jpg Development of a Lateral Flow Immunochromatographic Strip for Rapid and Quantitative Detection of Small Molecule Compounds Membrane-based lateral flow immunochromatographic strips (ICSs) are useful tools for low-cost self-diagnosis and have been efficiently applied to toxin, ... https://www.jove.com/v/62754 610 2021-11-13T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66677.jpg Rapid Detection of Bacterial Pathogens Causing Lower Respiratory Tract Infections via Microfluidic-Chip-Based Loop-Mediated Isothermal Amplification Various bacterial pathogens can cause respiratory tract infections and lead to serious health issues if not detected accurately and treated promptly. Rapid and accurate detection of these pathogens via loop-mediated isothermal amplification provides effective management and control of respiratory tract infections in clinical settings. https://www.jove.com/v/66677 371 2024-03-29T21:50:00+00:00 JoVE no https://visualize.jove.com/5086664-properties-and-purification-of-n-acetylmuramyl-l-alanine-amidase-from-staphylococcus-aureus-h monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12363.jpg Acid Halides to Amides: Aminolysis Aminolysis is a nucleophilic acyl substitution reaction, where ammonia or amines act as nucleophiles to give the substitution product. Acid halides react with ammonia, primary amines, and secondary amines to yield primary, secondary, and tertiary amides, respectively. In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride... https://www.jove.com/v/12363 67 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12529.jpg Preparation of Amines: Alkylation of Ammonia and Amines Alkylation is one of the methods used to prepare amines. Direct alkylation of ammonia or a primary amine with an alkyl halide gives polyalkylated amines along with a quaternary ammonium salt through successive SN2 reactions. This process of making the quaternary salt through the direct alkylation method is called exhaustive alkylation. Each alkylation step makes the nitrogen center more nucleophilic, which triggers successive alkylations until a quaternary ammonium salt is formed. Considering... https://www.jove.com/v/12529 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12530.jpg Preparation of 1° Amines: Azide Synthesis Direct alkylation of ammonia produces polyalkylated amines, along with a quaternary ammonium salt. To exclusively prepare primary amines, the azide synthesis method can be used. Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum... https://www.jove.com/v/12530 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12534.jpg Amines to Amides: Acylation of Amines Various carboxylic acid derivatives (such as acid chlorides, esters, and anhydrides) can be used for the acylation of amines to yield amides. The reaction requires two equivalents of amines. The first amine molecule functions as a nucleophile and attacks the carbonyl carbon to produce a tetrahedral intermediate. This is followed by the loss of the leaving group and restoration of the C=O bond. Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary amide... https://www.jove.com/v/12534 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12859.jpg Preparation of 1° Amines: Gabriel Synthesis Direct alkylation is not a suitable method for synthesizing amines because it produces polyalkylated products. Gabriel synthesis is the most preferred method to exclusively make primary amines. The method uses phthalimide, which contains a protected form of nitrogen that participates in alkylation only once to predominantly give primary amines. Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an... https://www.jove.com/v/12859 88 JoVE no https://cloudfront.jove.com/files/ftp_upload/40779/40779_article_thumb_40779.jpg Production of Organic Acids Lactic acid, an important organic acid extensively applied in food, pharmaceutical, and biodegradable polymer industries, is primarily produced via microbial fermentation. This method is favored over chemical synthesis due to its environmental sustainability and capacity for enantiomerically pure product formation. Among various microbial processes, the fermentation of starch-based substrates stands out due to the abundance and renewability of raw materials like corn and potatoes.Hydrolysis of... https://www.jove.com/v/40779 85 2026-03-12T20:35:47+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54652.jpg Preparation and In Vivo Use of an Activity-based Probe for N -acylethanolamine Acid Amidase Here, we describe the preparation and use of an activity-based probe (ARN14686, undec-10-ynyl-N-[(3S)-2-oxoazetidin-3-yl]carbamate) that allows for the detection and quantification of the active form of the proinflammatory enzyme N-acylethanolamine acid amidase (NAAA), both in vitro and ex vivo. https://www.jove.com/v/54652 661 2016-11-23T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57061.jpg A Facile Protocol to Generate Site-Specifically Acetylated Proteins in Escherichia Coli Genetic code expansion serves as a powerful tool to study a wide range of biological processes, including protein acetylation. Here we demonstrate a facile protocol to exploit this technique for generating homogeneously acetylated proteins at specific sites in Escherichia coli cells. https://www.jove.com/v/57061 668 2017-12-09T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57551.jpg Antimicrobial Peptides Produced by Selective Pressure Incorporation of Non-canonical Amino Acids The protocol presents the Escherichia coli-based selective pressure incorporation of non-canonical amino acids (ncAAs) into the lactococcal antimicrobial peptide nisin. Its properties can be changed during recombinant expression via substitution with desired ncAAs in defined growth media. Resulting changes in bioactivity are mapped by growth inhibition assays and fluorescence microscopy. https://www.jove.com/v/57551 716 2018-05-04T21:45:00+00:00 JoVE no https://visualize.jove.com/5651890-lifes-irreducible-structure-live-mechanisms-and-information-in-dna-are-boundary-conditions-with-a-sequence-of-boundaries-above-them monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4401.jpg Analyzing and Building Nucleic Acid Structures with 3DNA The 3DNA software package is a popular and versatile bioinformatics tool with capabilities to analyze, construct, and visualize three-dimensional nucleic acid structures. This article presents detailed protocols for a subset of new and popular features available in 3DNA, applicable to both individual structures and ensembles of related structures. https://www.jove.com/v/4401 984 2013-04-26T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10784.jpg The DNA Helix Overview Deoxyribonucleic acid, or DNA, is the genetic material responsible for passing traits from generation to generation in all organisms and most viruses. DNA is composed of two strands of nucleotides that wind around each other to form a double helix. The discovery of the structure of DNA occurred incrementally over nearly a century, representing one of the most famous and captivating stories in the history of science. DNA Structure in Detail Each strand of DNA consists of subunits... https://www.jove.com/v/10784 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10784.jpg The DNA Helix Overview Deoxyribonucleic acid, or DNA, is the genetic material responsible for passing traits from generation to generation in all organisms and most viruses. DNA is composed of two strands of nucleotides that wind around each other to form a double helix. The discovery of the structure of DNA occurred incrementally over nearly a century, representing one of the most famous and captivating stories in the history of science. DNA Structure in Detail Each strand of DNA consists of subunits... https://www.jove.com/v/11478 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11527.jpg DNA as a Genetic Template Two structural features of the DNA molecule provide a basis for the mechanisms of heredity: the four nucleotide bases and its double-stranded nature. The Watson-Crick model of double-helical DNA structure, proposed in 1952, drew heavily upon the X-ray crystallography work of researchers Rosalind Franklin and Maurice Wilkins. Watson, Crick, and Wilkins jointly received the Nobel Prize in Physiology or Medicine for their work in 1962. Franklin was, controversially, excluded from the prize for... https://www.jove.com/v/11527 125 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12441.jpg The DNA Helix Deoxyribonucleic acid, or DNA, is the genetic material responsible for passing traits from generation to generation in all organisms and most viruses. DNA is composed of two strands of nucleotides that wind around each other to form a spring-like structure called a double helix. However, the double helix is not perfectly symmetrical. Instead, there are regularly occurring grooves in the structure. The major groove occurs where the sugar-phosphate backbones are relatively far apart. This space... https://www.jove.com/v/12441 67 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12546.jpg Entropy within the Cell A living cell's primary tasks of obtaining, transforming, and using energy to do work may seem simple. However, the second law of thermodynamics explains why these tasks are harder than they appear. None of the energy transfers in the universe are completely efficient. In every energy transfer, some amount of energy is lost in a form that is unusable. In most cases, this form is heat energy. Thermodynamically, heat energy is defined as the energy transferred from one system to another that is... https://www.jove.com/v/12546 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11527.jpg DNA as a Genetic Template Two structural features of the DNA molecule provide a basis for the mechanisms of heredity: the four nucleotide bases and its double-stranded nature. The Watson-Crick model of double-helical DNA structure, proposed in 1952, drew heavily upon the X-ray crystallography work of researchers Rosalind Franklin and Maurice Wilkins. Watson, Crick, and Wilkins jointly received the Nobel Prize in Physiology or Medicine for their work in 1962. Franklin was, controversially, excluded from the prize for... https://www.jove.com/v/13180 125 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50268.jpg Designing a Bio-responsive Robot from DNA Origami DNA origami is a powerful method for fabricating precise nanoscale objects by programming the self-assembly of DNA molecules. Here, we describe how DNA origami can be utilized to design a robotic robot capable of sensing biological cues and responding by shape shifting, subsequently relayed to a desired effect. https://www.jove.com/v/50268 812 2013-07-08T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52486.jpg Self-assembly of Complex Two-dimensional Shapes from Single-stranded DNA Tiles DNA tiling is an effective approach to make programmable nanostructures. We describe the protocols to construct complex two-dimensional shapes by the self-assembly of single-stranded DNA tiles. https://www.jove.com/v/52486 623 2015-05-08T20:00:00+00:00 JoVE no https://visualize.jove.com/6237026-functional-interchangeability-of-dna-replication-genes-in-salmonella-typhimurium-and-escherichia-coli-demonstrated-by-a-general-complementation-procedure monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4056.jpg Mapping Bacterial Functional Networks and Pathways in Escherichia Coli using Synthetic Genetic Arrays Systematic, large-scale synthetic genetic (gene-gene or epistasis) interaction screens can be used to explore genetic redundancy and pathway cross-talk. Here, we describe a high-throughput quantitative synthetic genetic array screening technology, termed eSGA that we developed for elucidating epistatic relationships and exploring genetic interaction networks in Escherichia coli. https://www.jove.com/v/4056 846 2012-11-12T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10788.jpg Replication in Prokaryotes Overview DNA replication has three main steps: initiation, elongation, and termination. Replication in prokaryotes begins when initiator proteins bind to the single origin of replication (ori) on the cell’s circular chromosome. Replication then proceeds around the entire circle of the chromosome in each direction from two replication forks, resulting in two DNA molecules. Many Proteins Work Together to Replicate the Chromosome Replication is coordinated and carried out by a host of... https://www.jove.com/v/10788 155 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13195.jpg Replication in Prokaryotes DNA replication has three main steps: initiation, elongation, and termination. Replication in prokaryotes begins when initiator proteins bind to the single origin of replication (ori) on the cell's circular chromosome. Replication then proceeds around the entire circle of the chromosome in each direction from the two replication forks, resulting in two DNA molecules. Many Proteins Work Together to Replicate the Chromosome Replication is coordinated and carried out by a host of specialized... https://www.jove.com/v/13195 92 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13201.jpg Mismatch Repair Organisms are capable of detecting and fixing nucleotide mismatches that occur during DNA replication. This sophisticated process requires identifying the new strand and replacing the erroneous bases with correct nucleotides. Mismatch repair is coordinated by many proteins in both prokaryotes and eukaryotes. The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic... https://www.jove.com/v/13201 80 JoVE no https://cloudfront.jove.com/files/ftp_upload/19527/19527_article_thumb_19527.jpg Coordination of Gene Expression Processes in Bacteria The DNA replication, transcription, and translation processes are intricately coupled in bacteria, allowing efficient gene expression and rapid protein synthesis. While this physical and functional coordination is advantageous, it introduces challenges that bacteria overcome through specific regulatory mechanisms.Coupling of Replication, Transcription, and TranslationThe coupling of replication, transcription, and translation is a hallmark of bacterial gene expression. As the replisome unwinds... https://www.jove.com/v/19527 89 2025-06-12T15:56:55+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53850.jpg Functional Complementation Analysis (FCA): A Laboratory Exercise Designed and Implemented to Supplement the Teaching of Biochemical Pathways The validation of enzymatic activities involved in biochemical pathways can be elucidated using functional complementation analysis (FCA). Described in this manuscript is the FCA assay demonstrating the enzymatic activity of enzymes involved in the metabolism of amino acids, bacterial stringent response and bacterial peptidoglycan biosynthesis. https://www.jove.com/v/53850 567 2016-06-24T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59630.jpg Digital PCR-based Competitive Index for High-throughput Analysis of Fitness in Salmonella This molecular-based approach for determining bacterial fitness facilitates precise and accurate detection of microorganisms using unique genomic DNA barcodes that are quantified via digital PCR. The protocol describes calculating the competitive index for Salmonella strains; however, the technology is readily adaptable to protocols requiring absolute quantification of any genetically-malleable organism. https://www.jove.com/v/59630 431 2019-05-13T22:00:00+00:00 JoVE no https://visualize.jove.com/6291810-effects-of-angiotensin-iii-and-acth-on-aldosterone-secretion monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10893.jpg Hormonal Regulation The renin-aldosterone system is an endocrine system which guides the renal absorption of water and electrolytes, thus managing blood pressure and osmoregulation. Activation of the system begins in the kidneys with a small cluster of cells adjacent to the afferent and efferent blood vessels of the renal corpuscle. As the nephrons are filtering blood, juxtaglomerular cells monitor blood pressure. If they detect a decrease in pressure, they release the hormone renin into the bloodstream. <br... https://www.jove.com/v/10893 93 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15023.jpg Antihypertensive Drugs: Angiotensin-Converting Enzyme Inhibitors Angiotensin-converting enzyme (ACE), a vital component of the renin-angiotensin-aldosterone system, is abundant in lung endothelial cells. ACE converts the inactive decapeptide, angiotensin I, into the active octapeptide, angiotensin II. This potent vasoconstrictor narrows blood vessels, increasing resistance to blood flow and elevating blood pressure. Angiotensin II also stimulates aldosterone production, encouraging kidney cells to reabsorb more sodium and water from urine, thereby increasing... https://www.jove.com/v/15023 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15024.jpg Antihypertensive Drugs: Angiotensin II Receptor Blockers In the renin-angiotensin-aldosterone system, a hormone called angiotensin II plays a crucial role. It binds to the AT1 receptors in vascular smooth muscles coupled with Gq proteins. The activation of these receptors activates an enzyme called phospholipase C, which releases two molecules: inositol trisphosphate and diacylglycerol. These molecules cause a chain reaction that leads to the phosphorylation of myosin light chains and promotes interaction between actin and myosin, leading to smooth... https://www.jove.com/v/15024 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15025.jpg Antihypertensive Drugs: Direct Renin Inhibitors The renin-angiotensin-aldosterone system (RAAS) is an intricate physiological pathway involving numerous enzymes and hormones, including renin, angiotensin-converting enzyme (ACE), angiotensin I and II, and aldosterone. Imbalances within this system increase the production of angiotensin II and aldosterone. Increased angiotensin II levels promote vasoconstriction and blood pressure elevation. Concurrently, higher aldosterone levels stimulate sodium and water reabsorption in the kidneys,... https://www.jove.com/v/15025 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15302.jpg Hormonal Regulation of Blood Pressure Endocrinal or hormonal intervention in the cardiovascular system is predominantly exerted by the catecholamines - epinephrine and norepinephrine, as well as a slew of hormones that interact with renal function to modulate blood volume. Epinephrine and Norepinephrine The adrenal medulla releases epinephrine and norepinephrine, catecholamines that enhance and extend the sympathetic or "fight or flight" physiological response. These hormones escalate heart rate and the force of contraction while... https://www.jove.com/v/15302 77 JoVE no https://cloudfront.jove.com/files/ftp_upload/40896/40896_article_thumb_40896.jpg Cushing Syndrome II: Pathophysiology Cortisol production is normally governed by the hypothalamic–pituitary–adrenal (HPA) axis, which maintains hormonal balance through tightly regulated feedback mechanisms. Disruption of this regulatory system is central to the development of Cushing syndrome, whether the excess cortisol originates from external medications or internal pathology. Persistent cortisol elevation alters metabolism, immune function, and endocrine signaling, producing the characteristic clinical features of the... https://www.jove.com/v/40896 79 2026-04-13T21:37:37+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53866.jpg Receptor Autoradiography Protocol for the Localized Visualization of Angiotensin II Receptors Here we present a protocol to describe the localization of angiotensin II Type 1 receptors in the rat brain by quantitative, densitometric, in vitro receptor autoradiography using an iodine-125 labeled analog of angiotensin II. https://www.jove.com/v/53866 723 2016-06-07T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55716.jpg A Novel Method: Super-selective Adrenal Venous Sampling Super-selective' adrenal venous sampling (ssAVS, also called segmental adrenal venous sampling: sAVS) was performed using a micro-catheter to identify adrenal segment(s) that produce excessive amounts of hormones. The ssAVS technique was described, cases in which adrenal segmental lesion(s) were identified by ssAVS were presented, and the usefulness of ssAVS in future adrenal research was discussed. https://www.jove.com/v/55716 368 2017-09-15T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59016.jpg Primary Culture of Rat Adrenocortical Cells and Assays of Steroidogenic Functions The hormone secreted by the adrenal cortex is vital for animals against stress and diseases. Here, we present a protocol to culture the primary rat adrenal cells. It could be a good in vitro platform for investigating the mechanisms of the reagent of interest in adrenal steroidogenesis and lipid biosynthesis. https://www.jove.com/v/59016 273 2019-03-12T19:30:00+00:00 JoVE no https://visualize.jove.com/6300146-analysis-of-angiotensin-stimulated-sodium-transport-in-cultured-smooth-muscle-cells-from-rat-aorta monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15023.jpg Antihypertensive Drugs: Angiotensin-Converting Enzyme Inhibitors Angiotensin-converting enzyme (ACE), a vital component of the renin-angiotensin-aldosterone system, is abundant in lung endothelial cells. ACE converts the inactive decapeptide, angiotensin I, into the active octapeptide, angiotensin II. This potent vasoconstrictor narrows blood vessels, increasing resistance to blood flow and elevating blood pressure. Angiotensin II also stimulates aldosterone production, encouraging kidney cells to reabsorb more sodium and water from urine, thereby increasing... https://www.jove.com/v/15023 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15024.jpg Antihypertensive Drugs: Angiotensin II Receptor Blockers In the renin-angiotensin-aldosterone system, a hormone called angiotensin II plays a crucial role. It binds to the AT1 receptors in vascular smooth muscles coupled with Gq proteins. The activation of these receptors activates an enzyme called phospholipase C, which releases two molecules: inositol trisphosphate and diacylglycerol. These molecules cause a chain reaction that leads to the phosphorylation of myosin light chains and promotes interaction between actin and myosin, leading to smooth... https://www.jove.com/v/15024 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52734.jpg Two-photon Imaging of Intracellular Ca 2+ Handling and Nitric Oxide Production in Endothelial and Smooth Muscle Cells of an Isolated Rat Aorta Vascular cell functiondepends on activity of intracellular messengers. Described here is an ex vivo two photon imaging method that allows the measurement of intracellular calcium and nitric oxide levels in response to physiological and pharmacological stimuli in individual endothelial and smooth muscle cells of an isolated aorta. https://www.jove.com/v/52734 488 2015-06-10T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55177.jpg Live Cell Imaging and 3D Analysis of Angiotensin Receptor Type 1a Trafficking in Transfected Human Embryonic Kidney Cells Using Confocal Microscopy Here we present a protocol to image cells expressing green fluorescent protein-tagged angiotensin type 1a receptors during endocytosis initiated by angiotensin II treatment. This technique includes labeling lysosomes with a second fluorescent marker, and then utilizing software to analyze the co-localization of receptor and lysosome in three dimensions over time. https://www.jove.com/v/55177 591 2017-03-27T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56133.jpg Evaluation of Vascular Control Mechanisms Utilizing Video Microscopy of Isolated Resistance Arteries of Rats This manuscript describes in vitro video microscopy protocols for evaluating vascular function in rat cerebral resistance arteries. The manuscript also describes techniques for evaluating microvessel density with fluorescently labeled lectin and tissue perfusion using Laser Doppler Flowmetry. https://www.jove.com/v/56133 628 2017-12-05T20:30:00+00:00 JoVE no https://visualize.jove.com/6302285-topological-modifications-and-template-activation-are-induced-in-chimaeric-plasmids-by-inserted-sequences monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/10982/10982_article_thumb_10982.jpg Bacterial Transformation In 1928, bacteriologist Frederick Griffith worked on a vaccine for pneumonia, which is caused by Streptococcus pneumoniae bacteria. Griffith studied two pneumonia strains in mice: one pathogenic and one non-pathogenic. Only the pathogenic strain killed host mice.Griffith made an unexpected discovery when he killed the pathogenic strain and mixed its remains with the live, non-pathogenic strain. Not only did the mixture kill host mice, but it also contained living pathogenic bacteria that... https://www.jove.com/v/10982 93 2026-06-01T13:28:13+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11570.jpg Overview of Transposition and Recombination Transposons make up a significant part of genomes of various organisms. Therefore, it is believed that transposition played a major evolutionary role in speciation by changing genome sizes and modifying gene expression patterns. For example, in bacteria, transposition can lead to conferring antibiotic resistance. Movement of transposable elements within the genetic pool of pathogenic bacteria can aid in transfer of antibiotic-resistant genetic elements. In eukaryotes, transposons can carry out... https://www.jove.com/v/11570 133 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11571.jpg DNA-only Transposons DNA-only transposons are called autonomous transposons since they code for the enzyme transposase that is required for the transposition mechanism. Insertion of transposons can alter gene functions in multiple ways. They can mutate the gene, alter gene expression by introducing a novel promoter or insulator sequence, introduce new splice sites, and change the mRNA transcripts produced, or remodel chromatin structure. The donor site from where the transposon is excised is either degraded or... https://www.jove.com/v/11571 177 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11575.jpg Conservative Site-specific Recombination and Phase Variation Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines. The recognition sites for Cre recombinase called LoxP... https://www.jove.com/v/11575 173 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13482.jpg Chromatin Modification in iPS Cells Chromatin modification alters gene expression; therefore, scientists can add histone-modifying enzymes, histone variants, and chromatin remodeling complexes to somatic cells to aid reprogramming into pluripotent stem (iPS) cells. Compact chromatin makes reprogramming difficult. Enzymes, such as histone demethylases and acetyltransferases, are often added during reprogramming to loosen the chromatin, making the DNA more accessible to transcription factors. Molecules that inhibit histone... https://www.jove.com/v/13482 92 JoVE no https://cloudfront.jove.com/files/ftp_upload/19551/19551_article_thumb_19551.jpg Mechanism of Conjugation Bacterial conjugation is a mechanism of horizontal gene transfer that enables the exchange of genetic material between bacterial cells through direct contact. This process is facilitated by a donor cell carrying a conjugative plasmid, which encodes genes necessary for pilus formation, DNA replication, and transfer. The conjugative plasmid plays a central role in initiating and executing the transfer of genetic material.The tra region of the conjugative plasmid encodes proteins responsible for... https://www.jove.com/v/19551 79 2025-06-12T16:18:14+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55526.jpg CAPRRESI: Chimera Assembly by Plasmid Recovery and Restriction Enzyme Site Insertion Here, we present chimera assembly by plasmid recovery and restriction enzyme site insertion (CAPRRESI), a protocol based on the insertion of restriction enzyme sites into synonym DNA sequences and functional plasmid recovery. This protocol is a fast and low-cost method for fusing protein-coding genes. https://www.jove.com/v/55526 457 2017-06-25T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58786.jpg Identification of Functional Protein Regions Through Chimeric Protein Construction Structurally related proteins frequently exert distinct biological functions. The exchange of equivalent regions of these proteins in order to create chimeric proteins constitutes an innovative approach to identify critical protein regions that are responsible for their functional divergence. https://www.jove.com/v/58786 699 2019-01-08T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61993.jpg Rapid Assembly of Multi-Gene Constructs using Modular Golden Gate Cloning The goal of this protocol is to provide a detailed, step-by-step guide for assembling multi-gene constructs using the modular cloning system based on Golden Gate cloning. It also gives recommendations on critical steps to ensure optimal assembly based on our experiences. https://www.jove.com/v/61993 511 2021-02-05T21:30:00+00:00 JoVE no https://visualize.jove.com/6308575-interactions-of-rna-polymerase-and-the-cyclic-amp-receptor-protein-on-dna-of-the-e-coli-galactose-operon monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4182.jpg A Toolkit to Enable Hydrocarbon Conversion in Aqueous Environments A sustainable auto regulating bacterial system for the remediation of oil pollutions was designed using standard interchangeable DNA parts (BioBricks). An engineered E. coli strain was used to degrade alkanes via β-oxidation in toxic aqueous environments. The respective enzymes from different species showed alkane degradation activity. Additionally, an increased tolerance to n-hexane was achieved by introducing genes from alkane-tolerant bacteria. https://www.jove.com/v/4182 1228 2012-10-02T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10984.jpg Operons Prokaryotes can control gene expression through operons—DNA sequences consisting of regulatory elements and clustered, functionally related protein-coding genes. Operons use a single promoter sequence to initiate transcription of a gene cluster (i.e., a group of structural genes) into a single mRNA molecule. The terminator sequence ends transcription. An operator sequence, located between the promoter and structural genes, prohibits the operon’s transcriptional activity if bound by a repressor... https://www.jove.com/v/10984 129 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11609.jpg Prokaryotic Transcriptional Activators and Repressors The organization of prokaryotic genes in their genome is notably different from that of eukaryotes. Prokaryotic genes are organized, such that the genes for proteins involved in the same biochemical process or function are located together in groups. This group of genes, along with their regulatory elements, are collectively known as an operon. The functional genes in an operon are transcribed together to give a single strand of mRNA known as polycistronic mRNA. Transcription of prokaryotic... https://www.jove.com/v/11609 118 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11609.jpg Prokaryotic Transcriptional Activators and Repressors The organization of prokaryotic genes in their genome is notably different from that of eukaryotes. Prokaryotic genes are organized, such that the genes for proteins involved in the same biochemical process or function are located together in groups. This group of genes, along with their regulatory elements, are collectively known as an operon. The functional genes in an operon are transcribed together to give a single strand of mRNA known as polycistronic mRNA. Transcription of prokaryotic... https://www.jove.com/v/13145 118 JoVE no https://cloudfront.jove.com/files/ftp_upload/19533/19533_article_thumb_19533.jpg Inducible Operons: lac Operon The lac operon in Escherichia coli is a model for understanding inducible gene regulation and metabolic flexibility. It integrates local control by lactose and global regulation through catabolite repression, enabling E. coli to preferentially metabolize glucose when available and switch to lactose utilization when glucose is scarce.Structure and Function of the lac OperonThe lac operon contains three structural genes: lacZ (β-galactosidase), lacY (lactose permease), and lacA (thiogalactoside... https://www.jove.com/v/19533 85 2025-06-12T16:14:20+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19537/19537_article_thumb_19537.jpg Global Regulatory Systems Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource... https://www.jove.com/v/19537 88 2025-06-12T16:15:04+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19541/19541_article_thumb_19541.jpg Stringent Response in E. coli Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs... https://www.jove.com/v/19541 83 2025-06-12T16:16:17+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51715.jpg DNA-affinity-purified Chip (DAP-chip) Method to Determine Gene Targets for Bacterial Two component Regulatory Systems This video article describes an in vitro microarray based method to determine the gene targets and binding sites for two component system response regulators. https://www.jove.com/v/51715 744 2014-07-21T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52431.jpg The Multifaceted Benefits of Protein Co-expression in Escherichia coli Protein co-expression is a powerful alternative to the reconstitution in vitro of protein complexes, and is of help in performing biochemical and genetic tests in vivo. Here we report on the use of protein co-expression in Escherichia coli to obtain protein complexes, and to tune the mutation frequency of cells. https://www.jove.com/v/52431 768 2015-02-05T23:00:00+00:00 JoVE no https://visualize.jove.com/6314127-homologous-recombination-between-transfected-dnas monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11567.jpg Homologous Recombination The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the... https://www.jove.com/v/11567 151 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11569.jpg Gene Conversion Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new... https://www.jove.com/v/11569 128 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11575.jpg Conservative Site-specific Recombination and Phase Variation Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines. The recognition sites for Cre recombinase called LoxP... https://www.jove.com/v/11575 173 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11993.jpg Exon Recombination The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes. Exon shuffling follows “splice frame rules.” Each exon has three reading... https://www.jove.com/v/11993 152 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11567.jpg Homologous Recombination The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the... https://www.jove.com/v/13203 151 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11569.jpg Gene Conversion Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new... https://www.jove.com/v/13204 128 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50346.jpg Recombineering Homologous Recombination Constructs in Drosophila Homologous recombination techniques greatly advance Drosophila genetics by enabling the creation of molecularly precise mutations. The recent adoption of recombineering allows one to manipulate large pieces of DNA and transform them into Drosophila6. The methods presented here combine these techniques to rapidly generate large homologous recombination vectors. https://www.jove.com/v/50346 863 2013-07-13T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59658.jpg In Vivo Functional Study of Disease-associated Rare Human Variants Using Drosophila The goal of this protocol is to outline the design and performance of in vivo experiments in Drosophila melanogaster to assess the functional consequences of rare gene variants associated with human diseases. https://www.jove.com/v/59658 401 2019-08-20T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64240.jpg Detection of Homologous Recombination Intermediates via Proximity Ligation and Quantitative PCR in Saccharomyces cerevisiae The D-loop capture (DLC) and D-loop extension (DLE) assays utilize the principle of proximity ligation together with quantitative PCR to quantify D-loop formation, D-loop extension, and product formation at the site of an inducible double-stranded break in Saccharomyces cerevisiae. https://www.jove.com/v/64240 475 2022-09-11T20:00:00+00:00 JoVE no https://visualize.jove.com/6318652-can-extrachromosomal-genetic-elements-be-recognized-as-inventions monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3698.jpg Site-specific Bacterial Chromosome Engineering: ΦC31 Integrase Mediated Cassette Exchange (IMCE) A quick and efficient method to integrate foreign DNA of interest into pre-made acceptor strains, termed landing pad strains, is described. The method allows site-specific integration of a DNA cassette into the engineered landing pad locus of a given strain, through conjugation and expression of the ΦC31 integrase. https://www.jove.com/v/3698 501 2012-03-16T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10806.jpg What is Genetic Engineering? Overview Genetic engineering is the process of modifying an organism’s DNA to introduce new, desirable traits. Many organisms, from bacteria to plants and animals, have been genetically modified for academic, medical, agricultural, and industrial purposes. While genetic engineering has definite benefits, ethical concerns surround modifying humans and our food supply. Scientists can Deliberately Modify an Organism’s Genome Genetic engineering is possible because the genetic code—the way... https://www.jove.com/v/10806 49 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11010.jpg Chromosomal Theory of Inheritance In 1866, Gregor Mendel published the results of his pea plant breeding experiments, providing evidence for predictable patterns in the inheritance of physical characteristics. The significance of his findings was not immediately recognized. In fact, the existence of genes was unknown at the time. Mendel referred to hereditary units as “factors.” The mechanisms underlying Mendel’s observations—the basis of his laws of segregation and independent assortment—remained elusive. In the late 1800s,... https://www.jove.com/v/11010 99 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11485.jpg Genome Size and the Evolution of New Genes While every living organism has a genome of some kind (be it RNA, or DNA), there is considerable variation in the sizes of these blueprints. One major factor that impacts genome size is whether the organism is prokaryotic or eukaryotic. In prokaryotes, the genome contains little to no non-coding sequence, such that genes are tightly clustered in groups or operons sequentially along the chromosome. Conversely, the genes in eukaryotes are punctuated by long stretches of non-coding sequence. https://www.jove.com/v/11485 201 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11542.jpg Inheritance of Chromatin Structures Epigenetics is the study of inherited changes in a cell's phenotype without changing the DNA sequences. It provides a form of memory for the differential gene expression pattern to maintain cell lineage, position-effect variegation, dosage compensation, and maintenance of chromatin structures such as telomeres and centromeres. For example, the structure and location of the centromere on chromosomes are epigenetically inherited. Its functionality is not dictated or ensured by the underlying DNA... https://www.jove.com/v/11542 197 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11570.jpg Overview of Transposition and Recombination Transposons make up a significant part of genomes of various organisms. Therefore, it is believed that transposition played a major evolutionary role in speciation by changing genome sizes and modifying gene expression patterns. For example, in bacteria, transposition can lead to conferring antibiotic resistance. Movement of transposable elements within the genetic pool of pathogenic bacteria can aid in transfer of antibiotic-resistant genetic elements. In eukaryotes, transposons can carry out... https://www.jove.com/v/11570 133 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11575.jpg Conservative Site-specific Recombination and Phase Variation Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines. The recognition sites for Cre recombinase called LoxP... https://www.jove.com/v/11575 173 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50773.jpg A Rapid Protocol for Integrating Extrachromosomal Arrays With High Transmission Rate into the C. elegans Genome This protocol describes a rapid and low material consuming procedure for the integration of transgenic extrachromosomal arrays into the Caenorhabditis elegans genome using ultra violet (UV) irradiation. Furthermore, this protocol is particularly well suited for transgenic lines that transmit extrachromosomal arrays at a high rate. https://www.jove.com/v/50773 393 2013-12-10T04:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54239.jpg Genome-wide Purification of Extrachromosomal Circular DNA from Eukaryotic Cells This paper presents a sensitive method called Circle-Seq for purifying extrachromosomal circular DNA (eccDNA). The method encompasses column purification, removal of remaining linear chromosomal DNA, rolling-circle amplification and high-throughput sequencing. Circle-Seq is applicable to genome-scale screening of eukaryotic eccDNA and studying genome instability and copy-number variation. https://www.jove.com/v/54239 866 2016-04-04T20:00:00+00:00 JoVE no https://visualize.jove.com/6352843-expert-medical-consultation-systems monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13106.jpg Integrated Healthcare System An integrated healthcare system (IHS) is a set of organizations that provides for or arranges to provide coordinated and continuous service to a defined population. The IHS takes responsibility for that particular population's health status and outcome, both clinically and fiscally. An integrated healthcare system is a well-organized, well-coordinated, and collaborative network. The integrated delivery system is a network that connects different healthcare providers to deliver organized,... https://www.jove.com/v/13106 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14115.jpg Methods of Documentation VII: EMR Electronic Medical Records (EMRs) primarily center around electronically documenting patients' health information within a single healthcare organization or practice. They contain essential clinical data related to a patient's medical history, diagnoses, medications, treatment plans, lab results, and other pertinent information relevant to the specific encounter or episode of care. EMRs are designed to streamline documentation and workflow processes within individual healthcare settings,... https://www.jove.com/v/14115 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14125.jpg Health Information Technology and Healthcare Information System Health Information Technology (HIT) Health Information Technology, commonly called HIT, integrates advanced information systems and technology in healthcare settings. Its primary functions include: Documentation and Monitoring of Patient Care: HIT systems facilitate the efficient recording and tracking of patient data, aiding healthcare providers in monitoring patients' health status and making informed decisions. Managerial and Organizational Functions: Beyond patient care, HIT is... https://www.jove.com/v/14125 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14126.jpg Nursing Clinical Information System Nursing Clinical Information System (NCIS) A Nursing Clinical Information System (NCIS) is a specialized type of healthcare information system tailored to meet the unique needs of nursing practice. It incorporates the principles of nursing informatics to streamline information management and improve the quality of care delivery. Critical attributes of NCIS include: Efficient Information Management: NCIS is designed to manage patient information efficiently, making it easily accessible to... https://www.jove.com/v/14126 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14134.jpg Ethical Dilemmas II Resolving an ethical dilemma in healthcare involves a systematic approach that considers every aspect of the issue, respecting both the patient's needs and values and the healthcare professional's ethical obligations. Here are potential steps to resolve an ethical dilemma: Identify the ethical problem and dilemma: Begin by recognizing the presence of an ethical issue. An ethical dilemma arises when conflicting moral principles or values necessitate choosing between two or more equally... https://www.jove.com/v/14134 90 JoVE no https://cloudfront.jove.com/files/ftp_upload/40816/40816_article_thumb_40816.jpg Automated Microbial Diagnostics Automated diagnostic analyzers have transformed clinical microbiology by providing rapid and reliable methods for pathogen identification and antibiotic susceptibility testing. Among these systems, the Vitek 2 is widely used because it automates the traditionally labor-intensive processes of microbial identification (ID) and antibiotic susceptibility testing (AST), delivering standardized and timely results that are essential for effective patient care.Microbial Identification with ID CardsThe... https://www.jove.com/v/40816 84 2026-03-12T20:35:56+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58132.jpg Hydra, a Computer-Based Platform for Aiding Clinicians in Cardiovascular Analysis and Diagnosis This article presents a protocol based on Hydra — a web-based system for clinical decision support that integrates a full and detailed set of functionalities and services required by physicians for complete cardiovascular analysis, risk assessment, early diagnosis, treatment, and monitoring over time. https://www.jove.com/v/58132 471 2018-09-26T20:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63848.jpg A Computer-Based Platform for Aiding Clinicians in Eating Disorder Analysis and Diagnosis Diagnosing eating disorders in healthcare is challenging. Therefore, the present protocol develops an algorithm based on 949 patient responses to a questionnaire, with the diagnosis displayed on an easy-to-use web-based interface. This system facilitates the accurate diagnosis of eating disorders while excluding those believed to have an eating disorder. https://www.jove.com/v/63848 259 2022-05-10T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67525.jpg Evidence-based Knowledge Synthesis and Hypothesis Validation: Navigating Biomedical Knowledge Bases via Explainable AI and Agentic Systems This article describes RUGGED (Retrieval Under Graph-Guided Explainable disease Distinction), which integrates Large Language Model (LLM) inference with Retrieval-Augmented Generation (RAG). It draws evidence from expert-curated biomedical knowledge bases and peer-reviewed biomedical publications to synthesize new knowledge from up-to-date information, identify explainable and actionable predictions, and pinpoint promising directions for hypothesis-driven investigations. https://www.jove.com/v/67525 347 2025-06-13T20:10:00+00:00 JoVE no https://visualize.jove.com/6380351-correlation-of-a-micro-elisa-assay-with-the-skin-test-and-the-rast-assay-in-inhalant-allergy monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13383.jpg Enzyme-Linked Immunosorbent Assay In 1971, Peter Perlman and Eva Engvall developed an Enzyme-linked immunosorbent assay (ELISA or EIA). ELISA differs from western blot in that the assays are conducted in microtiter plates or in vivo rather than on an absorbent membrane. There are many different types of ELISAs, but they all involve an antibody molecule whose constant region binds an enzyme, leaving the variable region free to bind its specific antigen. Enzyme-substrate reaction allows the antigen to be visualized or quantified. https://www.jove.com/v/13383 93 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55723.jpg A Component-resolved Diagnostic Approach for a Study on Grass Pollen Allergens in Chinese Southerners with Allergic Rhinitis and/or Asthma This work describes a protocol that uses a component-resolved approach to study sensitization to grass pollen allergens in a cohort of patients from southern China with allergic rhinitis and/or asthma. https://www.jove.com/v/55723 394 2017-06-04T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59100.jpg Application of Biochip Microfluidic Technology to Detect Serum Allergen-specific Immunoglobulin E (sIgE) This paper presents a protocol for detecting serum-specific immunoglobulin E with a microfluidic cartridge-based chemiluminescence system and the evaluation of its usefulness in allergy diagnoses. https://www.jove.com/v/59100 430 2019-04-21T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67037.jpg Acupoint Catgut Embedding Therapy in Traditional Chinese Medicine for Managing Allergic Rhinitis This protocol details the procedure for acupoint burrowing and demonstrates its effectiveness in treating allergic rhinitis. https://www.jove.com/v/67037 220 2024-12-20T20:40:00+00:00 JoVE no https://visualize.jove.com/6381189-a-comparison-of-the-artificial-pancreas-glucose-controlled-insulin-infusion-system-and-a-manual-technique-for-assessing-insulin-sensitivity-during-euglycaemic-clamping monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2432.jpg Hyperinsulinemic-Euglycemic Clamp in the Conscious Rat The hyperinsulinemic-euglycemic clamp is the "gold standard" for the assessment of insulin action. Insulin is infused at a constant rate stimulating glucose uptake. The amount of exogenous glucose infused to counter this drop is indicative of insulin sensitivity. Here the procedure is performed on a conscious, unrestrained rat. https://www.jove.com/v/2432 672 2011-02-08T01:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/3188.jpg Hyperinsulinemic-euglycemic Clamps in Conscious, Unrestrained Mice The hyperinsulinemic-euglycemic clamp, or insulin clamp, is the gold standard for assessing insulin action in vivo. A method for performing insulin clamps in mice is described. This includes a method for arterial catheterization that permits experiments to be performed in conscious, unrestrained mice with minimal stress. https://www.jove.com/v/3188 670 2011-11-16T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17292.jpg Glucose Homeostasis: Pancreatic Islets and Insulin Secretion The pancreatic islets comprising only 1%-2% of the volume are highly vascularized and innervated mini-organs. They contain five endocrine cell types, including β cells that secrete insulin, which is synthesized as a single polypeptide chain, preproinsulin, processed to proinsulin, and finally to insulin and C-peptide. This process is complex and regulated, involving the Golgi complex, the endoplasmic reticulum, and the secretory granules of the β cell. Insulin and C-peptide are co-secreted in... https://www.jove.com/v/17292 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17299.jpg Insulin: Dosing Regimen and Adverse Effects Insulin-replacement therapy usually includes both long-acting insulin (basal) and short-acting insulin (to cater to postprandial needs). In a diverse group of type 1 diabetes patients, the average daily insulin dose is typically 0.5-0.7 units/kg body weight. However, obese patients and pubertal adolescents may need more due to insulin resistance. The basal dose constitutes about 40%-50% of the total daily dose, with the rest as premeal insulin. The mealtime insulin dose should mirror... https://www.jove.com/v/17299 76 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65581.jpg Hyperglycemic Clamp and Hypoglycemic Clamp in Conscious Mice A hyperglycemic clamp is used for measuring insulin release with a maintained higher blood glucose concentration. A hypoglycemic clamp is for measuring glucose production induced by counter-regulatory responses. Both methods use the same surgical procedure. Here, we present a clamp technique to assess systemic glucose metabolism. https://www.jove.com/v/65581 455 2024-01-26T21:10:00+00:00 JoVE no https://visualize.jove.com/6383704-computer-assisted-education-system-for-arrhythmia-caesar monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13286.jpg Pulse rhythm Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding. Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle... https://www.jove.com/v/13286 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15276.jpg Disturbances in Heart Rhythm Arrhythmia or dysrhythmia refers to an abnormal heart rhythm caused by a defect in the heart's conduction system. It can cause the heart to beat irregularly, too quickly, or too slowly, leading to symptoms like chest pain, shortness of breath, and fainting. Factors such as stress, caffeine, alcohol, nicotine, cocaine, certain drugs, congenital defects, diseases, and electrolyte abnormalities can trigger arrhythmias. Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart... https://www.jove.com/v/15276 89 2025-07-29T16:29:05+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17938/17938_article_thumb_17938.jpg Dysrhythmias I: Introduction Dysrhythmias refers to abnormalities in the heart's rhythm. They result from disruptions in the heart's electrical conduction system, which includes the sinoatrial(SA)node, atrioventricular(AV) node, the bundle of His, bundle branches, and Purkinje fibers.Definition and PathophysiologyDysrhythmias result from disorders of impulse formation, impulse conduction, or both. The heart contains specialized cells in the sinoatrial node, atrioventricular node, and the bundle of His and Purkinje fibers... https://www.jove.com/v/17938 75 2025-06-19T16:35:29+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17942/17942_article_thumb_17942.jpg Dysrhythmias V: Evaluating Dysrhythmias Dysrhythmias, also known as arrhythmias, are disturbances in the heart's rhythm that range from benign to life-threatening. A thorough evaluation is crucial for appropriate management and involves a comprehensive medical history, physical examination, and various diagnostic tests.Medical HistorySymptoms: Collect detailed information on palpitations, dizziness, syncope, chest pain, and fatigue. Note their onset, frequency, and triggers.Previous Cardiac Issues: Document any history of heart... https://www.jove.com/v/17942 90 2025-06-19T16:36:46+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17943/17943_article_thumb_17943.jpg Dysrhythmias VI: Management of Dysrhythmias Dysrhythmia management involves a multifaceted approach, incorporating pharmacological treatments, medical procedures, surgical interventions, lifestyle modifications, and patient education.Pharmacological ManagementAntiarrhythmic Drugs:Class I (Sodium Channel Blockers): This class includes quinidine and procainamide, which reduce the speed of impulse conduction in the heart, stabilize the cardiac membrane, and control arrhythmias. Quinidine and procainamide are Class IA agents that prolong the... https://www.jove.com/v/17943 85 2025-06-19T16:37:04+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17948/17948_article_thumb_17948.jpg Cardiopulmonary Resuscitation III: AED Use Introduction to AEDAn Automated External Defibrillator (AED) is a portable medical device that analyzes the heart's rhythm and, if necessary, delivers an electrical shock to help the heart re-establish an effective rhythm during sudden cardiac arrest (SCA). SCA occurs when the heart suddenly and unexpectedly stops beating, leading to a loss of blood flow to the brain and other vital organs. In such emergencies, time is of the essence, and using an AED, combined with Cardiopulmonary... https://www.jove.com/v/17948 83 2025-06-19T16:38:36+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56439.jpg Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing The establishment of a chronic asynchronous heart failure (HF) model by rapid pacing combined with left bundle branch ablation is presented. Two-dimensional speckle tracking imaging and aortic velocity time integral are applied to validate this stable HF model with left ventricular asynchrony and the benefits of cardiac resynchronization therapy. https://www.jove.com/v/56439 765 2017-12-11T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59019.jpg A Novel Digital Platform for a Monitored Home-based Cardiac Rehabilitation Program The aim is to promote a new approach to cardiac rehabilitation (CR), using a unique remote patient monitoring system that will enable healthcare providers to monitor CR patients at home at low cost, with the intention of making CR services more accessible and improving compliance. The study is currently underway. https://www.jove.com/v/59019 264 2019-04-19T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67620.jpg Surgical Implant Procedure and Wiring Configuration for Continuous Long-Term EEG/ECG Monitoring in Rabbits The study outlines a protocol for the design, manufacturing, and placement of a novel continuous EEG/ECG recording system in rabbits. This hard-wired system allows for continuous EEG/ECG recordings from nine distinct electrodes on the head and chest, which facilitates comprehensive assessments of electrical activity in the brain and heart. https://www.jove.com/v/67620 516 2025-01-24T22:45:00+00:00 JoVE no https://visualize.jove.com/6423635-wide-distribution-of-ph-dependent-service-of-transport-system-asc-for-both-anionic-and-zwitterionic-amino-acids monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11470.jpg Amino acids Amino acids are the monomers that comprise proteins. Each amino acid has the same fundamental structure, which consists of a central carbon atom, or the alpha (α) carbon, bonded to an amino group (NH2), a carboxyl group (COOH), and to a hydrogen atom. Every amino acid also has another atom or group of atoms bonded to the central atom known as the R group. There are 20 common amino acids present in proteins, each with a different R group. Variation in the amino acid sequence is responsible for... https://www.jove.com/v/11470 222 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14397.jpg Drug Absorption Mechanism: Carrier-Mediated Membrane Transport Certain large, lipid-insoluble drug molecules that resemble amino acids, peptides, or glucose, require specialized carrier proteins to facilitate their diffusion across cell membranes. This transport can occur through either facilitated diffusion, which does not require energy input, or active transport, which does require energy input. Facilitated diffusion is a passive process that utilizes human Solute Carrier (SLC) transporters. These transporters bind to the drug, undergo structural... https://www.jove.com/v/14397 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16494.jpg Pore Transport and Ion-Pair Transport Pore transport and ion-pair formation are critical mechanisms for the absorption and distribution of drugs in the body. Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct microscopic... https://www.jove.com/v/16494 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16495.jpg Carrier-Mediated Transport Carrier-mediated transport is a pivotal process in drug absorption, particularly for lipid-insoluble drugs, and encompasses facilitated diffusion and active transport. Facilitated diffusion allows drugs to move along their concentration gradient without energy expenditure, while active transport utilizes ATP to drive drug movement against this gradient. Active transport involves two types of membrane-spanning transporters: uptake and efflux. Uptake transporters are expressed in the small... https://www.jove.com/v/16495 66 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16496.jpg Facilitated Diffusion The plasma membrane, a critical structure in cellular biology, houses an array of transporters, or carrier proteins, interspersed within its lipid bilayer. These proteins play a crucial role in solute transport through facilitated diffusion, a form of passive diffusion that uses transporters to move the molecules across the membrane. In this process, substrates such as organic compounds and ions interact with a transporter on one side, triggering conformational changes in proteins that enable... https://www.jove.com/v/16496 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16497.jpg Active Transport Active transport is a critical biological process that allows cells to move solutes against an electrochemical gradient. This process requires direct energy input and is characterized by its selectivity, saturability, and susceptibility to competitive inhibition. Primary active transporters, like Na+, K+ and -ATPase, directly utilize ATP to move ions across the membrane. These transporters play significant roles in various physiological processes. For instance, Na+, K+ and -ATPase maintain... https://www.jove.com/v/16497 74 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60009.jpg Characterization of Membrane Transporters by Heterologous Expression in E. coli and Production of Membrane Vesicles We describe a method for the characterization of proton-driven membrane transporters in membrane vesicle preparations produced by heterologous expression in E. coli and lysis of cells using a French press. https://www.jove.com/v/60009 796 2019-12-31T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62578.jpg Selection of Transporter-Targeted Inhibitory Nanobodies by Solid-Supported-Membrane (SSM)-Based Electrophysiology Nanobodies are important tools in structural biology and pose a great potential for the development of therapies. However, the selection of nanobodies with inhibitory properties can be challenging. Here we demonstrate the use of solid-supported-membrane (SSM)-based electrophysiology for the classification of inhibitory and non-inhibitory nanobodies targeting electrogenic membrane transporters. https://www.jove.com/v/62578 552 2021-05-03T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66882.jpg Demonstration of Membrane Transport of Histidine using Goat Intestinal Inverted Sacs: An Experiential Pedagogical Tool for Undergraduates Here, we report an inexpensive and reproducible method demonstrating the membrane transport of histidine in a goat intestine. This process occurs by co-transporting histidine and sodium ions enabled by the sodium gradient across the enterocyte membrane. This method exploits experiential learning pedagogy to better understand solute movement across biological membranes. https://www.jove.com/v/66882 280 2024-10-04T20:45:00+00:00 JoVE no https://visualize.jove.com/6513941-computer-assisted-monitoring-in-intensive-care monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13286.jpg Pulse rhythm Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding. Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle... https://www.jove.com/v/13286 90 JoVE no https://cloudfront.jove.com/files/ftp_upload/17887/17887_article_thumb_17887.jpg Holter Monitor: 24-Hour Monitoring Holter monitoring is a continuous electrocardiography (ECG) recording that tracks the heart's electrical activity over an extended period, generally 24 to 48 hours. This noninvasive diagnostic tool detects irregular heart rhythms that may not be captured during a standard ECG performed in a clinical setting.DeviceThe Holter monitor is a portable, small device connected to several electrodes on the patient's chest. These electrodes detect the heart's electrical signals and transmit them to the... https://www.jove.com/v/17887 83 2025-06-19T16:09:27+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17964/17964_article_thumb_17964.jpg Cardiomyopathy VII: Pre and Post Operative Nursing Management Patients with hypertrophic cardiomyopathy (HCM) and left ventricular outflow tract (LVOT) obstruction who remain symptomatic despite optimal medical therapy may undergo a septal myectomy (Morrow procedure). This procedure involves excising a portion of the hypertrophied septum below the aortic valve using a heart-lung machine to improve blood flow through the LVOT. Effective preoperative and postoperative nursing management ensures successful patient outcomes, minimizes complications, and... https://www.jove.com/v/17964 88 2025-06-19T16:43:38+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56388.jpg A Detailed Protocol for Physiological Parameters Acquisition and Analysis in Neurosurgical Critical Patients Recently, we have developed a portable multimodality monitoring system for the monitoring of various physiological parameters in neurosurgical critical patients. Detailed protocols on how to use this multimodality monitoring system are presented here. https://www.jove.com/v/56388 301 2017-10-17T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58993.jpg A Bedside, Single Burr Hole Approach to Multimodality Monitoring in Severe Brain Injury A method of recording multimodality monitoring signals in patients with severe brain injuries using a bedside, single burr hole technique is described. https://www.jove.com/v/58993 378 2019-03-26T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61899.jpg Digital Home-Monitoring of Patients after Kidney Transplantation: The MACCS Platform The MACCS platform is a comprehensive telemedicine concept aiming at better outcomes after kidney transplantation by sharing key medical information between patients and physicians. A telemedicine team reviews incoming data to detect potential complications and to improve adherence in kidney transplant recipients to achieve better long-term outcomes. https://www.jove.com/v/61899 433 2021-04-12T19:30:00+00:00 JoVE no https://visualize.jove.com/6526941-an-effect-of-immediate-reinforcement-and-delayed-punishment-with-possible-implications-for-self-control monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1998.jpg Novel Apparatus and Method for Drug Reinforcement Operant drug self-administration and conditioned place preference (CPP) procedures are expansively used in research to model various components of drug reinforcement, consumption, and addiction in humans. In this report, we combined traditional CPP and self-administration methods as a novel approach to studying drug reinforcement and addiction in rats. https://www.jove.com/v/1998 452 2010-08-21T00:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17811.jpg Operant Conditioning Operant conditioning, a key concept in behavioral psychology, involves using reinforcement and punishment to alter the likelihood of a behavior being repeated. B.F. introduced this type of conditioning. Skinner focused on voluntary behaviors and the consequences that follow them, influencing whether these behaviors will be strengthened or diminished. Reinforcement in operant conditioning can be positive or negative, both of which serve to increase the likelihood of a behavior. Positive... https://www.jove.com/v/17811 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17812.jpg Law of Effect B.F. Skinner, a prominent figure in behavioral psychology, introduced operant conditioning by emphasizing the role of consequences in shaping behavior. This theory builds upon the law of effect proposed by Edward Thorndike, which posits that behaviors followed by satisfying outcomes are likely to be repeated. In contrast, those followed by unsatisfying outcomes are less likely to recur. Edward Thorndike's foundational work involved studying learning in animals, particularly using puzzle boxes... https://www.jove.com/v/17812 66 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17813.jpg Reinforcement Positive and negative reinforcement are key concepts in operant conditioning, a learning process where the consequences of a behavior affect the likelihood of that behavior being repeated. Positive reinforcement occurs when a behavior is followed by the presentation of a rewarding stimulus, increasing the frequency of that behavior. For example: • If a person smiles at you after you greet them and you continue talking, the smile is a positive reinforcement for your greeting. • Teaching a dog... https://www.jove.com/v/17813 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17815.jpg Punishment Negative reinforcement and punishment are often confused but serve distinct functions in behavior modification. Reinforcement, whether positive or negative, increases the likelihood of a desired behavior, while punishment decreases it. Punishment can be positive or negative. Positive punishment involves adding an undesirable stimulus, such as scolding, to decrease a behavior. Negative punishment involves removing a desirable stimulus, such as taking away a favorite toy, to decrease behavior. https://www.jove.com/v/17815 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17820.jpg Timing and Consequences on Behavior In operant conditioning, the timing of reinforcement is crucial. For animals like rats and cats, immediate reinforcement (within a few seconds) is much more effective than delayed reinforcement. For example, a food reward for a rat needs to follow within 30 seconds of pressing a bar to be effective. Humans, however, can respond to delayed reinforcers. We often make decisions between immediate small rewards and delayed larger rewards. This ability to delay gratification is a significant factor... https://www.jove.com/v/17820 68 JoVE no https://cloudfront.jove.com/files/ftp_upload/19910/19910_article_thumb_19910.jpg Self-Regulation Self-regulation, also known as self-control, encompasses a range of cognitive and behavioral processes that allow individuals to adjust their internal states and outward actions to align with socially acceptable norms and long-term goals. It plays a fundamental role in adaptive functioning, from resisting impulsive behaviors to persisting through challenging tasks. While its benefits are widely recognized, self-regulation is not limitless. Muraven and Baumeister's theory posits that... https://www.jove.com/v/19910 85 2025-09-18T17:23:57+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53283.jpg Errors as a Means of Reducing Impulsive Food Choice Giving in to temptation of tasty food may result in long-term overweight problems. This protocol describes how to reduce imprudent preference for edible commodities during hypothetical intertemporal choices in women by associating them with errors. https://www.jove.com/v/53283 427 2016-06-05T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59070.jpg Three Laboratory Procedures for Assessing Different Manifestations of Impulsivity in Rats We present three protocols that assess different forms of impulsivity in rats and other small mammals. Intertemporal choice procedures evaluate the tendency to discount the value of delayed outcomes. Differential reinforcement of low rates and feature-negative discrimination evaluate response inhibition capacity with and without punishment for inappropriate responses, respectively. https://www.jove.com/v/59070 552 2019-03-17T20:00:00+00:00 JoVE no https://visualize.jove.com/6546140-computer-analysis-of-intraoperative-cardiac-rhythms-using-esophageal-and-surface-leads monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13286.jpg Pulse rhythm Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding. Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle... https://www.jove.com/v/13286 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15273.jpg Electrocardiogram An electrocardiogram (ECG or EKG) is a critical diagnostic tool that records the electrical signals produced by the heart during each heartbeat. This recording is achieved through electrodes placed strategically on the arms, legs, and chest. The electrocardiograph amplifies these signals and produces 12 distinct tracings, offering a comprehensive understanding of the heart's electrical activity. Three major waveforms are present in a typical ECG recording: the P wave, the QRS complex, and the T... https://www.jove.com/v/15273 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17877.jpg Electrocardiogram Fundamentals Introduction An electrocardiogram (ECG) is a diagnostic tool for identifying cardiac conditions such as arrhythmias, conduction abnormalities, and myocardial ischemia. Definition An electrocardiogram (ECG) visualizes the heart's electrical activity by tracing the electrical movement associated with each heartbeat on a graph or monitor. As the heart beats, an electrical wave passes through it, correlating with the cardiac cycle events. Parts of an ECG An ECG utilizes electrodes on the skin to... https://www.jove.com/v/17877 88 JoVE no https://cloudfront.jove.com/files/ftp_upload/17942/17942_article_thumb_17942.jpg Dysrhythmias V: Evaluating Dysrhythmias Dysrhythmias, also known as arrhythmias, are disturbances in the heart's rhythm that range from benign to life-threatening. A thorough evaluation is crucial for appropriate management and involves a comprehensive medical history, physical examination, and various diagnostic tests.Medical HistorySymptoms: Collect detailed information on palpitations, dizziness, syncope, chest pain, and fatigue. Note their onset, frequency, and triggers.Previous Cardiac Issues: Document any history of heart... https://www.jove.com/v/17942 90 2025-06-19T16:36:46+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50124.jpg A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis Continuous 12-lead electrocardiographic (ECG) monitoring can identify transient myocardial ischemia, even when asymptomatic, among patients with suspected acute coronary syndrome (ACS). In this article we describe our method for initiating patient monitoring using a Holter device, downloading the ECG data for off-line analysis, and how to utilize the ECG software to identify transient ischemia. https://www.jove.com/v/50124 1091 2012-12-28T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67001.jpg Rat Model of Right-Sided Cardiac Remodeling and Arrhythmia Using Pulmonary Artery Banding Right heart failure (RHF) is characterized by right-sided cardiac dilation and hypertrophy, leading to ventricular and atrial malfunction. Cardiopulmonary conditions associated with RHF are accompanied by an increased risk for cardiac arrhythmias. This article describes a standardized model of pulmonary artery banding-induced RHF associated with enhanced ventricular and atrial arrhythmogenesis. https://www.jove.com/v/67001 639 2024-08-30T20:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67958.jpg Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System This study introduces a novel approach for real-time cardiac mapping using a noninvasive, imageless electrocardiographic imaging system. This system enables the acquisition of electrophysiological cardiac maps without requiring pre-procedural computed tomography or magnetic resonance imaging scans, enabling efficient guidance for cardiac procedures such as ablation and cardiac resynchronization therapy implants. https://www.jove.com/v/67958 617 2025-04-11T21:20:00+00:00 JoVE no https://visualize.jove.com/6564828-in-vitro-activity-of-augmentin-against-clinically-important-gram-positive-and-gram-negative-bacteria-in-comparison-with-other-antibiotics monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10807.jpg Antibiotic Selection Overview Researchers use antibiotic resistance genes to identify bacteria that possess a plasmid containing their gene of interest. Antibiotic resistance naturally occurs when a spontaneous DNA mutation creates changes in bacterial genes that eliminate antibiotic activity. Bacteria can share these new resistance genes with their offspring and other bacteria. The overuse and misuse of antibiotics have created a public health crisis, as resistant and multi-resistant bacteria continue to develop.<br... https://www.jove.com/v/10807 57 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14435.jpg Combined Effects of Drugs: Synergism Synergism is a useful mechanism where combining two or more drugs is more effective than each constituent used alone. Such combinations are also called supra-additive interactions. The drugs collectively enhance the final therapeutic effect by acting on different targets. Another advantage is that the low dose of each constituent drug is sufficient to achieve the desired effect. This helps reduce the duration of therapy and lower the adverse effects of these drugs. Such synergistic combinations... https://www.jove.com/v/14435 87 JoVE no https://cloudfront.jove.com/files/ftp_upload/19522/19522_article_thumb_19522.jpg Antimicrobial Effectiveness The effectiveness of antimicrobial agents depends on various factors influencing their ability to eliminate microbial populations. Larger microbial populations require more time for complete eradication, emphasizing the importance of population size analysis when evaluating antimicrobial efficacy.Microbial resistance to antimicrobial agents varies significantly. Highly resilient microorganisms include endospores, gram-negative bacteria, and non-enveloped viruses, while prions are exceptionally... https://www.jove.com/v/19522 88 2025-06-12T16:43:38+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40859/40859_article_thumb_40859.jpg Inhibitors of Gram-positive Cell Wall Synthesis Bacterial cell walls are typically rigid structures composed mainly of peptidoglycan, a mesh-like polymer that provides mechanical strength and maintains cell shape. The synthesis of peptidoglycan is a crucial process in bacterial growth and serves as a primary target for many antibiotics.Mechanism of Action of Beta-Lactam AntibioticsBeta-lactam antibiotics, such as penicillin, inhibit peptidoglycan synthesis in actively growing cells. These antibiotics share a characteristic four-membered... https://www.jove.com/v/40859 83 2026-03-12T20:36:02+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40860/40860_article_thumb_40860.jpg Inhibitors of Bacterial Protein Synthesis Aminoglycosides constitute a highly potent class of bactericidal antibiotics that exert their antimicrobial effects by targeting the bacterial ribosome, specifically disrupting protein synthesis. These polycationic molecules consist of amino-modified sugars linked via glycosidic bonds to an aminocyclitol core such as 2-deoxystreptamine or streptamine. Their strong positive charges facilitate tight binding to the negatively charged phosphate backbone of ribosomal RNA (rRNA), primarily at the 16S... https://www.jove.com/v/40860 85 2026-03-12T20:36:04+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40867/40867_article_thumb_40867.jpg Clinical Significance of Antibiotic Resistance Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One... https://www.jove.com/v/40867 85 2026-03-12T20:36:05+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58636.jpg Antimicrobial Synergy Testing by the Inkjet Printer-assisted Automated Checkerboard Array and the Manual Time-kill Method Antimicrobial synergy testing is used to evaluate the effect of two or more antibiotics used in combination and is typically performed by one of two methods: the checkerboard array or the time-kill assay. Here, we present an automated, inkjet printer-assisted checkerboard array synergy technique and a classic time-kill synergy study. https://www.jove.com/v/58636 723 2019-04-18T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62187.jpg Antibiotic Efficacy Testing in an Ex vivo Model of Pseudomonas aeruginosa and Staphylococcus aureus Biofilms in the Cystic Fibrosis Lung This workflow can be used to perform antibiotic susceptibility testing using an established ex vivo model of bacterial biofilm in the lungs of individuals with cystic fibrosis. Use of this model could enhance the clinical validity of MBEC (minimal biofilm eradication concentration) assays. https://www.jove.com/v/62187 566 2021-01-22T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64712.jpg Evaluation of Antimicrobial Activities of Nanoparticles and Nanostructured Surfaces In Vitro We introduce four methods to evaluate the antimicrobial activities of nanoparticles and nanostructured surfaces using in vitro techniques. These methods can be adapted to study the interactions of different nanoparticles and nanostructured surfaces with a broad range of microbial species. https://www.jove.com/v/64712 712 2023-04-21T21:40:00+00:00 JoVE no https://visualize.jove.com/6573085-cytologic-atypias-in-the-uterine-fluid-of-intrauterine-contraceptive-device-users monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10906.jpg Oogenesis In human women, oogenesis produces one mature egg cell or ovum for every precursor cell that enters meiosis. This process differs in two unique ways from the equivalent procedure of spermatogenesis in males. First, meiotic divisions during oogenesis are asymmetric, meaning that a large oocyte (containing most of the cytoplasm) and minor polar body are produced as a result of meiosis I, and again following meiosis II. Since only oocytes will go on to form embryos if fertilized, this unequal... https://www.jove.com/v/10906 127 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16304.jpg Uterine Tubes The uterine or fallopian tubes function as the conduit through which oocytes travel from the ovaries to the uterus. Each fallopian tube measures approximately 10 to 13 cm long and is anatomically divided into the infundibulum, ampulla, isthmus, and interstitial part (or intramural segment). The infundibulum is characterized by its funnel shape and features extensions called fimbriae which reach towards the peritoneal cavity. These fimbriae play a critical role during ovulation as they extend... https://www.jove.com/v/16304 76 JoVE no https://cloudfront.jove.com/files/ftp_upload/17260/17260_article_thumb_17260.jpg Intrauterine Drug Delivery Systems Controlled-release systems for intravaginal and intrauterine drug delivery have been developed primarily for the administration of contraceptive steroid hormones. These delivery routes circumvent first-pass hepatic metabolism, thereby enhancing bioavailability and allowing for reduced systemic dosages compared to oral administration. Such approaches contribute to improved therapeutic efficacy and patient compliance, particularly in long-term contraceptive regimens.Intravaginal Drug Delivery... https://www.jove.com/v/17260 81 2026-02-12T19:17:26+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51906.jpg Collection, Isolation, and Flow Cytometric Analysis of Human Endocervical Samples The use of cytobrush sampling to collect lymphocytes and monocytes from the endocervix is a minimally invasive technique that provides samples for analysis of female genital tract immunity. In this protocol, we describe the collection of cytobrush samples and immune cell isolation for flow cytometry assays. https://www.jove.com/v/51906 754 2014-07-06T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55887.jpg Tubal Cytology of the Fallopian Tube as a Promising Tool for Ovarian Cancer Early Detection We explored a tubal cytologic method by sampling the fallopian tube directly post-surgical excision as a tool of ovarian cancer early detection. Here, we present a protocol to collect fallopian tube cells from freshly received surgical specimens. https://www.jove.com/v/55887 489 2017-07-25T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62670.jpg Isolation of Uterine Innate Lymphoid Cells for Analysis by Flow Cytometry This is a method to isolate uterine lymphoid cells from both pregnant and non-pregnant mice. This method can be used for multiple downstream applications such as FACS phenotyping, cell sorting, functional assays, RNA-seq, and proteomics. The protocol here demonstrates how to phenotype group 1 uterine innate lymphoid cells by flow cytometry. https://www.jove.com/v/62670 542 2021-10-14T20:30:00+00:00 JoVE no https://visualize.jove.com/6578744-a-comparison-of-automated-data-collection-and-manual-data-collection-for-toxicology-studies monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12577.jpg Data Collection by Experiments Data collection is a systematic method of obtaining, observing, measuring, and analyzing accurate information. An experimental study is a standard method of data collection that involves the manipulation of the samples by applying some form of treatment prior to data collection. It refers to manipulating one variable to determine its changes on another variable. The sample subjected to treatment is known as “experimental units.” An example of the experimental method is a public clinical trial... https://www.jove.com/v/12577 73 JoVE no https://cloudfront.jove.com/files/ftp_upload/17190/17190_article_thumb_17190.jpg Therapeutic Drug Monitoring: Drug Analysis Methods Therapeutic Drug Monitoring (TDM) is a clinical practice that measures specific drug levels in a patient's blood or body tissues to tailor drug therapy effectively. This monitoring is critical for managing drugs with narrow therapeutic indices like digoxin and phenytoin, ensuring they are both safe and effective. For instance, monitoring theophylline levels in asthma patients involves precision and sensitivity to adjust doses according to individual responses to therapy, ensuring efficacy and... https://www.jove.com/v/17190 86 2025-10-03T14:00:18+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17272/17272_article_thumb_17272.jpg Toxicokinetics: Overview Studies that assess how a drug is absorbed, distributed, metabolized, and excreted (ADME) at toxic doses are termed toxicokinetics. Understanding toxicokinetics helps predict adverse drug reactions (ADRs) and manage toxicity in humans.Toxicokinetics differs from pharmacokinetics mainly in the dose levels studied, with toxicokinetics focusing on higher toxic doses. The kinetics at these levels can be non-linear due to altered physiological processes. Toxicodynamics examines the relationship... https://www.jove.com/v/17272 81 2026-02-12T19:17:25+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17273/17273_article_thumb_17273.jpg Toxicity Testing in Animals Toxicity tests in animals are grounded on two main assumptions: first, the effects observed in laboratory animals can be extrapolated to humans, especially when adjusted for body surface area; second, high-dose exposure in animals is essential to identify potential human hazards from lower doses. This is based on the quantal dose-response concept, which faces the challenge of extrapolating results from relatively few test animals to much larger human populations. For example, a 0.01% incidence... https://www.jove.com/v/17273 83 2026-02-12T19:17:01+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40816/40816_article_thumb_40816.jpg Automated Microbial Diagnostics Automated diagnostic analyzers have transformed clinical microbiology by providing rapid and reliable methods for pathogen identification and antibiotic susceptibility testing. Among these systems, the Vitek 2 is widely used because it automates the traditionally labor-intensive processes of microbial identification (ID) and antibiotic susceptibility testing (AST), delivering standardized and timely results that are essential for effective patient care.Microbial Identification with ID CardsThe... https://www.jove.com/v/40816 84 2026-03-12T20:35:56+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52333.jpg Human Pluripotent Stem Cell Based Developmental Toxicity Assays for Chemical Safety Screening and Systems Biology Data Generation The protocols describe two in vitro developmental toxicity test systems (UKK and UKN1) based on human embryonic stem cells and transcriptome studies. The test systems predict human developmental toxicity hazard, and may contribute to reduce animal studies, costs and the time required for chemical safety testing. https://www.jove.com/v/52333 1048 2015-06-17T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59082.jpg A High-throughput Assay for the Prediction of Chemical Toxicity by Automated Phenotypic Profiling of Caenorhabditis elegans A quantitative method has been developed to identify and predict the acute toxicity of chemicals by automatically analyzing the phenotypic profiling of Caenorhabditis elegans. This protocol describes how to treat worms with chemicals in a 384-well plate, capture videos, and quantify toxicological related phenotypes. https://www.jove.com/v/59082 541 2019-03-14T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60054.jpg In Silico Modeling Method for Computational Aquatic Toxicology of Endocrine Disruptors: A Software-Based Approach Using QSAR Toolbox Quantitative structure-activity relationship (QSAR) modeling is a representative bioinformatics-assisted method in toxicological screening. This protocol demonstrates how to computationally assess the risks of endocrine disruptors (EDs) in aquatic environments. Utilizing the OECD QSAR Toolbox, the protocol implements an in silico assay for analyzing toxicity of EDs in fish. https://www.jove.com/v/60054 347 2019-08-28T21:00:00+00:00 JoVE no https://visualize.jove.com/6605347-amplification-of-adenosine-deaminase-gene-sequences-in-deoxycoformycin-resistant-rat-hepatoma-cells monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2160.jpg Adenovirus-mediated Genetic Removal of Signaling Molecules in Cultured Primary Mouse Embryonic Fibroblasts In this video we use an adenovirus carrying the Cre recombinase gene to infect primary mouse embryonic fibroblasts carrying a floxed Rac1 allele. https://www.jove.com/v/2160 660 2010-09-10T00:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/2538.jpg High-Efficiency Transduction of Liver Cancer Cells by Recombinant Adeno-Associated Virus Serotype 3 Vectors In this article, we describe the identification of the adeno-associated virus serotype 3 (AAV3) as the most efficient vector for targeting human liver cancer cells. <br... https://www.jove.com/v/2538 1142 2011-03-22T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67216.jpg Determining the Serum Stability of Human Adenosine Deaminase 1 Enzyme In this article, we detail methods to characterize an enzyme's ability to retain function when incubated at 37 °C in human serum, a pharmacological property referred to as its serum stability. This ability may be a key factor in predicting an enzyme's pharmacokinetic profile and its suitability for therapeutic use. https://www.jove.com/v/67216 257 2024-09-27T21:25:00+00:00 JoVE no https://visualize.jove.com/6645553-an-automatic-electronic-apparatus-for-generating-and-recording-a-ramp-stimulus-for-analgesia-testing monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/53800.jpg Determining Pain Detection and Tolerance Thresholds Using an Integrated, Multi-Modal Pain Task Battery Human pain models are valuable tools used to assess the analgesic potential of novel compounds and predict their clinical efficacy, especially when used in an integrated manner. Although implementation of these models is complex, with proper execution, the pain models described in this protocol can provide predictive and reliable results. https://www.jove.com/v/53800 578 2016-04-14T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59057.jpg Multi-Modal Signals for Analyzing Pain Responses to Thermal and Electrical Stimuli This article focuses on the experimental elicitation of pain through heat (thermal) and electrical stimulation while recording physiological, visual, and paralinguistic responses. It aims at collecting valid multimodal data for analyzing pain based on its intensity, quality, and... https://www.jove.com/v/59057 556 2019-04-05T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61717.jpg Investigating Pain-Related Avoidance Behavior using a Robotic Arm-Reaching Paradigm Avoidance is central to chronic pain disability, yet adequate paradigms for examining pain-related avoidance are lacking. Therefore, we developed a paradigm that allows investigating how pain-related avoidance behavior is learned (acquisition), spreads to other stimuli (generalization), can be mitigated (extinction), and how it may subsequently re-emerge (spontaneous recovery). https://www.jove.com/v/61717 540 2020-10-03T21:00:00+00:00 JoVE no https://visualize.jove.com/6696981-possibility-of-hydrocortisone-induction-of-intertissue-recombination-of-dna-fragments monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3150.jpg Quantitation and Analysis of the Formation of HO-Endonuclease Stimulated Chromosomal Translocations by Single-Strand Annealing in Saccharomyces cerevisiae The HO-stimulated translocation assay monitors single-strand annealing following the creation of DNA double-strand breaks at multiple loci in diploid Saccharomyces cerevisiae. This mechanism may model genome rearrangements in somatic cells of higher eukaryotes following exposure to high doses of ionizing radiation. https://www.jove.com/v/3150 580 2011-09-23T22:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10769.jpg Crossing Over Unlike mitosis, meiosis aims for genetic diversity in its creation of haploid gametes. Dividing germ cells first begin this process in prophase I, where each chromosome—replicated in S phase—is now composed of two sister chromatids (identical copies) joined centrally. The homologous pairs of sister chromosomes—one from the maternal and one from the paternal genome—then begin to align alongside each other lengthwise, matching corresponding DNA positions in a process called synapsis. In order to... https://www.jove.com/v/10769 94 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11567.jpg Homologous Recombination The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the... https://www.jove.com/v/11567 151 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11569.jpg Gene Conversion Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new... https://www.jove.com/v/11569 128 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11575.jpg Conservative Site-specific Recombination and Phase Variation Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines. The recognition sites for Cre recombinase called LoxP... https://www.jove.com/v/11575 173 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11567.jpg Homologous Recombination The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the... https://www.jove.com/v/13203 151 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13438.jpg Crossing Over Crossing over is the exchange of genetic information between homologous chromosomes during prophase I of meiosis I. Genetic recombination gives rise to allelic diversity in the newly formed daughter cells. In humans, crossing over produces genetically distinct haploid egg and sperm cells that undergo fertilization to produce unique offspring. Before cell division starts, the germ cell’s chromosome(s) undergo duplication in the S phase of the cell cycle. As the cells enter prophase I, duplicated... https://www.jove.com/v/13438 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61447.jpg Visualization of DNA Repair Proteins Interaction by Immunofluorescence Following DNA damage, human cells activate essential repair pathways to restore the integrity of their genome. Here, we describe the method of indirect immunofluorescence as a means to detect DNA repair proteins, analyze their spatial and temporal recruitment, and help interrogate protein-protein interaction at the sites of DNA damage. https://www.jove.com/v/61447 475 2020-06-26T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64240.jpg Detection of Homologous Recombination Intermediates via Proximity Ligation and Quantitative PCR in Saccharomyces cerevisiae The D-loop capture (DLC) and D-loop extension (DLE) assays utilize the principle of proximity ligation together with quantitative PCR to quantify D-loop formation, D-loop extension, and product formation at the site of an inducible double-stranded break in Saccharomyces cerevisiae. https://www.jove.com/v/64240 475 2022-09-11T20:00:00+00:00 JoVE no https://visualize.jove.com/6709670-effects-of-chronic-intermittent-and-continuous-amphetamine-administration-on-acoustic-startle monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3361.jpg Biomarkers in an Animal Model for Revealing Neural, Hematologic, and Behavioral Correlates of PTSD We describe a rat model of post traumatic stress disorder (PTSD) that reveals the persistent alterations in neuroendocrine function and the delayed long-term, exaggerated fear response, characteristic of PTSD patients. The animal model and methods described here are useful for correlating biomarkers in brain nuclei, which are mechanistic but cannot be measured in patients, with biomarkers in peripheral white blood cells, which can. https://www.jove.com/v/3361 509 2012-10-10T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/3446.jpg Habituation and Prepulse Inhibition of Acoustic Startle in Rodents Habituation and prepulse inhibition of startle are operational measures of sensory gating. Sensory gating is disrupted in schizophrenia, and some other mental disorders and neurodegenerative diseases. We here describe a standard protocol to assess short-term and long-term habituation as well as prepulse inhibition of acoustic startle responses in rats and mice. https://www.jove.com/v/3446 518 2011-09-01T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51905.jpg Using the Threat Probability Task to Assess Anxiety and Fear During Uncertain and Certain Threat Potentiation of the startle reflex is measured via electromyography of the orbicularis oculi muscle during low (uncertain) and high (certain) probability electric shock threat in the Threat Probability Task. This provides an objective measure of distinct negative emotional states (fear/anxiety) for research on psychopathology, substance use/abuse, and broad affective science. https://www.jove.com/v/51905 678 2014-09-12T21:00:00+00:00 JoVE no https://visualize.jove.com/6827217-linear-systems-analysis-of-infant-visual-pattern-preferences monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17769.jpg Visual System Light enters the eye through the cornea, a transparent, dome-shaped surface covering the surface of the eyeball that helps to direct and focus incoming light. This light is then channeled toward the pupil, an adjustable opening whose size is controlled by the iris. The iris, a pigmented muscle, regulates the amount of light entering the eye by contracting or dilating the pupil, thereby ensuring optimal light levels for clear vision. Once through the pupil, the light passes through the lens, a... https://www.jove.com/v/17769 86 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54031.jpg A Method to Quantify Visual Information Processing in Children Using Eye Tracking A method is described to quantify the quality of visual information processing based on reflexive eye movements in response to specific visual modalities. Reaction times and fixation output parameters are used to characterize visual performance in children with and without visual impairments from 6 months of age. https://www.jove.com/v/54031 587 2016-07-09T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59581.jpg Exploring Infant Sensitivity to Visual Language using Eye Tracking and the Preferential Looking Paradigm Eye tracking studies using a preferential looking paradigm can be used to study infants' emerging understanding of, and attention to, their external visual world. https://www.jove.com/v/59581 367 2019-05-15T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65274.jpg An Automated Method for Assessing Visual Acuity in Infants and Toddlers Using an Eye-Tracking System In this paper, we present a novel automated method for assessing visual acuity in infants and toddlers by using an eye-tracking system. https://www.jove.com/v/65274 310 2023-03-17T20:30:00+00:00 JoVE no https://visualize.jove.com/6853482-stimulation-of-calf-thymus-dna-alpha-polymerase-by-atp monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4449.jpg Study of the DNA Damage Checkpoint using Xenopus Egg Extracts Xenopus egg extract is a useful model system to investigate the DNA damage checkpoint. This protocol is for the preparation of Xenopus egg extracts and DNA damage checkpoint inducing reagents. These techniques are adaptable to a variety of DNA damaging approaches in the study of the DNA damage checkpoint signaling. https://www.jove.com/v/4449 655 2012-11-05T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11564.jpg Translesion DNA Polymerases Translesion (TLS) polymerases rescue stalled DNA polymerases at sites of damaged bases by replacing the replicative polymerase and installing a nucleotide across the damaged site. Doing so, TLS allows additional time for the cell to repair the damage before resuming regular DNA replication. TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that... https://www.jove.com/v/11564 130 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11566.jpg DNA Damage can Stall the Cell Cycle In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at... https://www.jove.com/v/11566 156 2025-12-12T21:27:29+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11568.jpg Restarting Stalled Replication Forks DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a... https://www.jove.com/v/11568 157 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11901.jpg ATP Synthase: Mechanism In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP... https://www.jove.com/v/11901 108 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12221.jpg Allosteric Proteins-ATCase Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor. Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,... https://www.jove.com/v/12221 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11566.jpg DNA Damage Can Stall the Cell Cycle In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at... https://www.jove.com/v/13205 156 2025-12-12T21:26:51+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51593.jpg Stimulation of Cytoplasmic DNA Sensing Pathways In Vitro and In Vivo The aim of the protocol is to use optimal methods for stimulating the cytoplasmic DNA sensing pathways in cells and in vivo. This is achieved by improving the generation of long, double-stranded DNA during blunt-end ligation. Cells or mice are then transfected using a lipid transfection reagent. https://www.jove.com/v/51593 704 2014-09-18T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63147.jpg CD Spectroscopy to Study DNA-Protein Interactions The interaction of an ATP-dependent chromatin remodeler with a DNA ligand is described using CD spectroscopy. The induced conformational changes on a gene promoter analyzed by the peaks generated can be used to understand the mechanism of transcriptional regulation. https://www.jove.com/v/63147 408 2022-02-10T22:00:00+00:00 JoVE no https://visualize.jove.com/6927840-nucleotide-sequence-of-human-preproinsulin-complementary-dna monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10808.jpg Recombinant DNA Overview Scientists create recombinant DNA by combining DNA from different sources—often, other species—in the laboratory. DNA cloning allows researchers to study specific genes by inserting them into easily manipulated cells, such as bacteria. Organisms that contain recombinant DNA are known as genetically modified organisms (GMOs). Recombinant DNA technology produces organisms with new genes that can benefit science, medicine, and agriculture. How Do Scientists Create Recombinant DNA? <br... https://www.jove.com/v/10808 69 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10818.jpg Complementary DNA Overview Only genes that are transcribed into messenger RNA (mRNA) are active, or expressed. Scientists can, therefore, extract the mRNA from cells to study gene expression in different cells and tissues. The scientist converts mRNA into complementary DNA (cDNA) via reverse transcription. Because mRNA does not contain introns (non-coding regions) and other regulatory sequences, cDNA—unlike genomic DNA—also allows researchers to directly determine the amino acid sequence of the peptide encoded... https://www.jove.com/v/10818 104 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11003.jpg pre-mRNA Processing In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA. Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a “cap” to the 5’ end of the growing transcript. In this process, a 5’ phosphate is replaced by modified guanosine that has a methyl group attached to it (7-Methyl guanosine). This 5’ cap helps the... https://www.jove.com/v/11003 121 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11991.jpg Multi-species Conserved Sequences Next-generation sequencing technologies have created large genomic databases of a variety of animals and plants. Ever since the human genome project was completed, scientists studied the genome of primates, mammals, and other phylogenetically distant living beings. Such large-scale studies have provided new insights into the evolutionary relationship between organisms. Although the genome of each species varies greatly from each other, a few sequences are highly conserved. Such conserved DNA... https://www.jove.com/v/11991 171 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10818.jpg Complementary DNA Overview Only genes that are transcribed into messenger RNA (mRNA) are active, or expressed. Scientists can, therefore, extract the mRNA from cells to study gene expression in different cells and tissues. The scientist converts mRNA into complementary DNA (cDNA) via reverse transcription. Because mRNA does not contain introns (non-coding regions) and other regulatory sequences, cDNA—unlike genomic DNA—also allows researchers to directly determine the amino acid sequence of the peptide encoded... https://www.jove.com/v/12015 104 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17297.jpg Insulin: Biosynthesis, Chemistry, and Preparation The endoplasmic reticulum (ER) of pancreatic β-cells synthesizes preproinsulin, which consists of a signal peptide, A and B chains, and a C-peptide. Preproinsulin is then cleaved and folded into proinsulin, which translocates to the Golgi apparatus for sorting and packaging into secretory granules. In these granules, enzymatic clipping generates insulin and C-peptide. Damage or functional impairment of β-cells inhibits insulin production, leading to diabetes. Diabetes treatment primarily uses... https://www.jove.com/v/17297 85 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57627.jpg Single Cell Multiplex Reverse Transcription Polymerase Chain Reaction After Patch-clamp This protocol describes the critical steps and precautions required to perform single cell multiplex reverse transcription polymerase chain reaction after patch-clamp. This technique is a simple and effective method to analyze the expression profile of a predetermined set of genes from a single cell characterized by patch-clamp recordings. https://www.jove.com/v/57627 644 2018-06-20T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59866.jpg Single-cell RNA Sequencing and Analysis of Human Pancreatic Islets Here, we present a protocol to generate high-quality, large-scale transcriptome data of single cells from isolated human pancreatic islets using a droplet-based microfluidic single-cell RNA sequencing technology. https://www.jove.com/v/59866 694 2019-07-18T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62497.jpg In vitro Induction of Human Dental Pulp Stem Cells Toward Pancreatic Lineages This protocol presents a comparison between two different induction protocols for differentiating human dental pulp stem cells (hDPSCs) toward pancreatic lineages in vitro: the integrative protocol and the non-integrative protocol. The integrative protocol generates more insulin producing cells (IPCs). https://www.jove.com/v/62497 452 2021-09-25T21:30:00+00:00 JoVE no https://visualize.jove.com/7028729-interviewing-with-intravenous-drugs monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2968.jpg Delivery of Therapeutic Agents Through Intracerebroventricular (ICV) and Intravenous (IV) Injection in Mice This article demonstrates two very different methods of injection: 1) into the brain (intracerebroventricular) and 2) systemic (intravenous) to introduce the therapeutic agents into the central nervous system of neonatal mice. https://www.jove.com/v/2968 355 2011-10-03T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/3739.jpg Methods for Intravenous Self Administration in a Mouse Model The intravenous self-administration (IVSA) paradigm is considered to be the gold standard in examining the reinforcing properties of drugs of abuse in rodents. This manuscript outlines the experimental procedures and surgical techniques necessary to obtain reliable IVSA data. In particular, meticulous catheter implantation and maintenance are highlighted. https://www.jove.com/v/3739 729 2012-12-08T22:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14382.jpg Routes of Drug Administration: Parenteral The administration of drugs via parenteral routes allows for direct drug introduction into the systemic circulation, resulting in high bioavailability because the medication bypasses the harsh conditions of the gastrointestinal tract and hepatic metabolism. The intravenous route (IV) of drug administration can be further categorized into two types. The bolus injection administers the entire dose rapidly, while an intravenous infusion slowly delivers smaller doses steadily. The IV route is often... https://www.jove.com/v/14382 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16489.jpg Drug Delivery: Parenteral Route The parenteral route is a critical method of drug administration. It delivers compounds directly into the systemic circulation and bypasses the gastrointestinal tract. This approach is particularly advantageous for drugs that exhibit poor absorption or instability when administered orally. There are three primary parenteral routes: intravenous (IV), intramuscular (IM), and subcutaneous (SC). The IV route introduces the drug directly into the bloodstream, ensuring immediate action. The IM route... https://www.jove.com/v/16489 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16602.jpg Nonlinear Pharmacokinetics: Drug Elimination for IV Bolus Injection In pharmacokinetics, the elimination rate of a drug following a capacity-limited model is primarily controlled by two parameters: Vmax and KM. These parameters are crucial in how the drug behaves inside the body after administration. Following the administration of a single intravenous (IV) bolus injection, we can determine the concentration of the drug in the plasma at any given time. This calculation is achieved using a specific equation that integrates the values of Vmax and KM. We can also... https://www.jove.com/v/16602 59 JoVE no https://cloudfront.jove.com/files/ftp_upload/17182/17182_article_thumb_17182.jpg Drug Accumulation During Multiple Dosing: Repetitive IV Injections Calculating drug dosage and accumulation in multiple-dose regimens is crucial for achieving therapeutic efficacy while avoiding toxicity. This involves determining the plasma drug concentrations over time to optimize dosing schedules. The principle of superposition is fundamental in this process, allowing for the prediction of drug concentration in plasma following multiple doses based on single-dose data.The principle of superposition asserts that the plasma concentration-time curves from... https://www.jove.com/v/17182 81 2025-10-03T14:00:06+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17183/17183_article_thumb_17183.jpg Drug Accumulation During Multiple Dosing: Intermittent IV Infusions Intermittent intravenous (IV) infusion is a method of drug administration where medications are delivered over short infusion periods followed by intervals of no drug delivery. This approach helps to prevent sustained high drug concentrations in the bloodstream, reducing the risk of adverse effects associated with prolonged exposure. Unlike continuous infusion, steady-state concentrations may not be achieved during a single dosing cycle but can be reached through repeated... https://www.jove.com/v/17183 84 2025-10-03T14:00:28+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17187/17187_article_thumb_17187.jpg IV Infusion to Oral Dosing: Conversion Methods The development of extended-release formulations has facilitated the transition from intravenous to oral medication, offering a more convenient and patient-friendly approach to drug administration. This transition, however, requires careful management to ensure that therapeutic drug levels are maintained, preserving efficacy and avoiding adverse effects. Understanding pharmacokinetic principles and dosage calculations is critical during this process.Pharmacokinetics of the... https://www.jove.com/v/17187 88 2026-02-12T20:23:32+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63576.jpg The Motivation for Alcohol Reward: Predictors of Progressive-Ratio Intravenous Alcohol Self-Administration in Humans This study aims to show that the Progressive-Ratio Computer-assisted Alcohol-Infusion System (CAIS) paradigm is a reliable and sensitive method that can be used to examine the motivating properties associated with alcohol self-administration in humans. https://www.jove.com/v/63576 340 2022-04-28T19:40:00+00:00 JoVE no https://visualize.jove.com/7106395-limitations-on-input-as-a-basis-for-neural-organization-and-perceptual-development-a-preliminary-theoretical-statement monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3358.jpg Creating Objects and Object Categories for Studying Perception and Perceptual Learning We describe a novel methodology for creating naturalistic 3-D objects and object categories with precisely defined feature variations. We use simulations of the biological processes of morphogenesis and phylogenesis to create novel, naturalistic virtual 3-D objects and object categories that can then be rendered as visual images or haptic objects. https://www.jove.com/v/3358 878 2012-11-02T22:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10858.jpg Vision Vision is the result of light being detected and transduced into neural signals by the retina of the eye. This information is then further analyzed and interpreted by the brain. First, light enters the front of the eye and is focused by the cornea and lens onto the retina—a thin sheet of neural tissue lining the back of the eye. Because of refraction through the convex lens of the eye, images are projected onto the retina upside-down and reversed. Light is absorbed by the rod and cone... https://www.jove.com/v/10858 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17767.jpg Perception Perception is a fundamental psychological process that enables individuals to organize, interpret, and consciously experience sensory information. This process is crucial for understanding and interacting with the world around us. It includes both bottom-up and top-down processing, each playing a distinct role in how we perceive our environment. Bottom-up processing begins at the sensory level, where receptors detect external environmental stimuli. These could include the tactile sensation of... https://www.jove.com/v/17767 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17769.jpg Visual System Light enters the eye through the cornea, a transparent, dome-shaped surface covering the surface of the eyeball that helps to direct and focus incoming light. This light is then channeled toward the pupil, an adjustable opening whose size is controlled by the iris. The iris, a pigmented muscle, regulates the amount of light entering the eye by contracting or dilating the pupil, thereby ensuring optimal light levels for clear vision. Once through the pupil, the light passes through the lens, a... https://www.jove.com/v/17769 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17774.jpg Gestalt Principles of Perception Gestalt principles provide a framework for understanding how humans perceive objects as unified wholes within their context. These principles are essential in explaining the cognitive processes that make sense of complex visual stimuli by organizing them into coherent groups. One fundamental principle is proximity, which posits that objects located close to each other are perceived as a collective group. For instance, when dots are positioned near one another, the visual system interprets them... https://www.jove.com/v/17774 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17779.jpg Parallel Processing The brain processes sensory information rapidly due to parallel processing, which involves sending data across multiple neural pathways at the same time. This method allows the brain to manage various sensory qualities, such as shapes, colors, movements, and locations, all concurrently. For instance, when observing a forest landscape, the brain simultaneously processes the movement of leaves, the shapes of trees, the depth between them, and the various shades of green. This enables a quick and... https://www.jove.com/v/17779 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18560.jpg The Nativist Approach The nativist approach to infant cognitive development proposes that infants are born with inherent knowledge structures that allow them to interpret the world almost immediately. This perspective contrasts with earlier developmental theories, such as those proposed by Jean Piaget, which emphasized a more gradual acquisition of cognitive abilities through interaction with the environment. One key concept in this approach is object permanence — the understanding that objects continue to exist... https://www.jove.com/v/18560 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51128.jpg A Fully Automated Rodent Conditioning Protocol for Sensorimotor Integration and Cognitive Control Experiments A fully automated protocol for rodent operant conditioning is proposed. The protocol relies on precise temporal control of behavioral events to investigate the extent to which this control influences neural activity underlying sensorimotor integration and cognitive control experiments. https://www.jove.com/v/51128 583 2014-04-16T01:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52341.jpg Closed-loop Neuro-robotic Experiments to Test Computational Properties of Neuronal Networks In this paper, an experimental framework to perform closed-loop experiments is presented, in which information processing (i.e., coding and decoding) and learning of neuronal assemblies are studied during the continuous interaction with a robotic body. https://www.jove.com/v/52341 678 2015-03-02T22:00:00+00:00 JoVE no https://visualize.jove.com/7136008-assessment-of-observer-variability-in-the-classification-of-human-cataracts monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3524.jpg Doppler Optical Coherence Tomography of Retinal Circulation Total retinal blood flow is measured by Doppler optical coherence tomography and semi-automated grading software. https://www.jove.com/v/3524 646 2012-09-18T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60673.jpg Assessing Early Stage Open-Angle Glaucoma in Patients by Isolated-Check Visual Evoked Potential The isolated-check visual evoked potential (icVEP) method is implemented here to assess the magnocellular ON pathway that is initially damaged in glaucoma. The study shows standard operative procedures using icVEP to obtain reliable results. It is proved to serve as a useful objective diagnosing technology for the early detection of glaucoma. https://www.jove.com/v/60673 431 2020-05-25T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68422.jpg Comparison of Agreement and Accuracy using Binocular Wavefront Optometer with Autorefractor and Phoropter The binocular wavefront optometer agrees well with traditional refraction techniques in both objective and subjective refraction measurements, offering superior accuracy and clinical utility. Its standardized protocol reduces optometrist workload and provides a more accurate refractive assessment for post-refractive surgery individuals. https://www.jove.com/v/68422 314 2025-09-16T19:30:00+00:00 JoVE no https://visualize.jove.com/7171601-the-effect-of-amine-structure-on-complexation-with-lasalocid-in-model-membrane-systems-ii-ionophore-selectivity-for-amines-in-lipid-bilayers-and-at-oilwater-interfaces monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11456.jpg Metal-Ligand Bonds The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes. In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in... https://www.jove.com/v/11456 171 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11510.jpg Ligand Binding Sites Proteins are dynamic macromolecules that carry out a wide variety of essential processes; however, the activities of most proteins depend on their interactions with other molecules or ions, known as ligands. Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the... https://www.jove.com/v/11510 160 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12250.jpg Assembly of the Lipid Bilayer in the ER Biological membranes are more than just a barrier separating cell cytoplasm from the outside environment. They are highly dynamic and help maintain the integrity and physiological stability of the cells as well as membrane-bound organelles. Membranes also play vital roles in cell-to-cell and intracellular communication. A large chunk of any biological membrane is composed of phospholipids. These lipids have a heterogeneous distribution across different subcellular organelles and even between... https://www.jove.com/v/12250 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12527.jpg Basicity of Heterocyclic Aromatic Amines Heterocyclic amines, where the N atom is a part of an alicyclic system, are similar in basicity to alkylamines. Interestingly, the heterocyclic amine having a nitrogen atom as part of an aromatic ring has much less basicity than its corresponding alicyclic counterpart. For this reason, as presented in Figure 1, piperidine (pKb = 2.8) is significantly more basic than pyridine (pKb = 8.8). Figure 1. The comparison of the basicity of piperidine and pyridine. This difference in basicity may be... https://www.jove.com/v/12527 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14537.jpg Complexation Equilibria: The Chelate Effect In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen... https://www.jove.com/v/14537 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14745.jpg Complexation Equilibria: Factors Influencing Stability of Complexes In complexation reactions, metal cations are the electron pair acceptors, and the ligands are the electron pair donors. The stability of the metal complexes depends primarily on the complexing ability of the central metal ion and the nature of the ligands. Generally, the complexing ability of the metal ion depends on the size and charge of the ion. As the metal ion size increases, the stability of the metal complexes decreases, provided that the valency of the metal ion and the ligands remain... https://www.jove.com/v/14745 69 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53073.jpg Biomembrane Fabrication by the Solvent-assisted Lipid Bilayer (SALB) Method We present an experimental protocol to form a supported lipid bilayer on solid substrates without using lipid vesicles. We demonstrate a one-step method to form a lipid bilayer on silicon dioxide and gold as well as supported membranes with cholesterol-enriched domain for various biological applications. https://www.jove.com/v/53073 578 2015-12-01T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65712.jpg Realistic Membrane Modeling Using Complex Lipid Mixtures in Simulation Studies Membrane lipid diversity in structure and composition is an important contributor to cellular processes and can be a marker of disease. Molecular dynamics simulations allow us to study membranes and their interactions with biomolecules at atomistic resolution. Here, we provide a protocol to build, run, and analyze complex membrane systems. https://www.jove.com/v/65712 451 2023-09-01T21:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68594.jpg A Liposome Membrane Permeability Assay for Investigating the Effects of Phosphatidylinositol Phosphate Groups on Membranotropic Action of Venom PLA 2 We present a cost-effective method for assessing liposomal membrane permeability with superior sensitivity and resolution over conventional techniques. Using a novel encapsulated ligand substitution reaction, this technique detects phospholipase A2-induced changes in model membranes. Easily integrated with standard analyses, this accessible approach enhances resolution for studying membrane biophysics and toxin interactions. https://www.jove.com/v/68594 631 2025-09-26T21:00:00+00:00 JoVE no https://visualize.jove.com/7209713-anaesthesia-for-the-asthmatic monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2428.jpg Bronchial Thermoplasty: A Novel Therapeutic Approach to Severe Asthma Bronchial thermoplasty is a non-drug procedure for severe persistent asthma that delivers thermal energy to the airway wall in a precisely controlled manner to reduce excessive airway smooth muscle. Reducing airway smooth muscle decreases the ability of the airways to constrict, thereby reducing the frequency of asthma attacks. https://www.jove.com/v/2428 879 2010-11-05T00:10:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15191.jpg Inhalational Anesthetics: Overview Inhalation anesthetics are drugs that induce general anesthesia upon inhalation. They work by increasing the sensitivity of GABAA receptors or inhibiting NMDA receptors, leading to a decrease in central nervous system activity. The depth of anesthesia can be rapidly adjusted by changing the concentration of the inhaled gas. Some common examples of inhalational anesthetics include volatile liquids like isoflurane, desflurane, sevoflurane and gases like xenon and nitrous oxide. Isoflurane, a... https://www.jove.com/v/15191 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15228.jpg Asthma: Pathogenesis and Management Asthma is a chronic pulmonary condition involving inflammation of the airways, hyper-reactivity, and reversible obstruction of the airways. This condition can significantly impact a person's quality of life, making breathing difficult and leading to distressing symptoms. Asthma is classified as allergic and non-allergic. Allergens such as dust mites, pollen, and pet dander trigger allergic asthma, while factors like cold air, intense emotions, or exercise can induce non-allergic asthma. https://www.jove.com/v/15228 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15229.jpg Antiasthma Drugs: β 2 -Adrenoceptor Agonists Bronchodilators are critical in managing asthma, a chronic respiratory condition characterized by airway constriction due to inflammation and hyper-reactivity. Specifically, bronchodilators ease this constriction by relaxing the bronchial muscles, facilitating easier breathing. One class of bronchodilators includes β2-adrenoceptor agonists. These agents target the β2-adrenoceptors located on bronchial smooth muscle cells. By stimulating these receptors, β2-agonists induce relaxation in these... https://www.jove.com/v/15229 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15230.jpg Antiasthma Drugs: Methylxanthines Theophylline, a member of the methylxanthine class of bronchodilators, has long been used in asthma management. While its exact mechanism of action is not fully understood, it is believed to have multiple effects on various cellular processes. Theophylline is thought to inhibit phosphodiesterase enzymes, increasing intracellular levels of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). This rise in cAMP and cGMP concentrations stimulates cardiac function,... https://www.jove.com/v/15230 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16363.jpg Asthma-IV: Diagnostic and Management The diagnosis and management of asthma are comprehensive, encompassing clinical assessments, lung function tests, and pharmacological interventions. Here's an overview: Clinical Assessment for Asthma: This is the first step in diagnosing and managing asthma. It includes: Detailed Medical History: This includes asking about symptoms such as wheezing, coughing, chest tightness, and breathlessness. Information about triggers like exercise, allergens, or cold air is crucial. Physical... https://www.jove.com/v/16363 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16364.jpg Asthma-IV: Nursing Management The nursing management of asthma is a comprehensive approach that relies heavily on the expertise and dedication of healthcare professionals. It involves thorough assessment, accurate diagnosis, strategic planning, effective implementation, and diligent evaluation. By meticulously following this step-by-step process, healthcare professionals play a crucial role in providing the best possible care and treatment for patients with asthma, enhancing their overall health and well-being. First, in... https://www.jove.com/v/16364 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55116.jpg Topical Airway Anesthesia for Awake-endoscopic Intubation Using the Spray-as-you-go Technique with High Oxygen Flow The topical anesthetic lidocaine was atomized using a high oxygen flow through the working channel of a flexible intubating endoscope to achieve topical airway anesthesia for awake endotracheal intubation. We prefer this modified spray-as-you-go technique for endoscopic intubation to classical bolus application because of higher patient satisfaction and better compliance. https://www.jove.com/v/55116 343 2017-01-13T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65235.jpg Non-Intubated Video-Assisted Thoracoscopic Surgery Here, we present a non-intubated protocol for performing video-assisted thoracoscopic surgery with preserved autonomic breathing. https://www.jove.com/v/65235 339 2023-05-26T19:10:00+00:00 JoVE no https://visualize.jove.com/7218971-inversion-versus-amputation-of-the-appendix-an-objective-comparison-of-440-randomized-cases-authors-transl monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16438.jpg Appendicitis-I: Introduction The appendix, a small, narrow, blind tube extending from the inferior part of the cecum, is widely regarded as a vestigial organ, having lost much of its original function through evolution. Despite its diminished role, the appendix can become inflamed, a condition known as appendicitis. Etiology: Appendicitis can arise from various causes, primarily rooted in the obstruction of the appendix lumen. Factors contributing to this obstruction include fecal accumulation, lymphoid hyperplasia and, in... https://www.jove.com/v/16438 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16439.jpg Appendicitis-II: Diagnostic Studies and Management Diagnosing and managing appendicitis requires a structured and comprehensive approach that spans from initial assessment to postoperative care. Here is an overview of the process: Diagnosing Appendicitis It requires a multifaceted approach, starting with a detailed physical examination to pinpoint the location and nature of the pain and identify any associated symptoms. Laboratory tests play a crucial role. A complete Blood Count (CBC) typically reveals leukocytosis (an increased number of... https://www.jove.com/v/16439 89 JoVE no https://cloudfront.jove.com/files/ftp_upload/41010/41010_article_thumb_41010.jpg Appendicitis Appendicitis is an acute inflammatory condition of the vermiform appendix, most commonly caused by obstruction of its lumen. The appendix is a narrow, blind-ended pouch that extends from the cecum, making it particularly prone to obstruction. Causes include fecaliths, lymphoid hyperplasia (often after viral infections), parasites, tumors, or foreign bodies. This obstruction initiates a cascade of pathological changes.Luminal Obstruction and Early InflammationAfter obstruction, normal mucosal... https://www.jove.com/v/41010 79 2026-04-15T15:51:19+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59921.jpg Murine Appendectomy Model of Chronic Colitis Associated Colorectal Cancer by Precise Localization of Caecal Patch The presented protocol describes a facile surgical removal of the appendix (caecal patch) in a mouse followed by the induction of inflammatory bowel disease-associated colorectal cancer. This murine appendectomy model enables investigation of the biological role of the appendix in the pathogenesis of human gastrointestinal disease. https://www.jove.com/v/59921 531 2019-08-24T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66808.jpg Laparoscopic Anatomical Liver Segment VII Resection with Liver Parenchymal Transection Following a Priority Approach This protocol involves a laparoscopic anatomical resection of liver segment VII with liver parenchymal transection following a priority approach. This technique is unaffected by anatomical variations. https://www.jove.com/v/66808 837 2025-05-23T19:35:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/69484.jpg Caudal-to-cranial Approach in Laparoscopic Right Hemicolectomy with Complete Mesocolon Excision and D3 Lymph Node Dissection Laparoscopic surgery is widely used in the treatment of right-sided colon cancer and offers numerous advantages. This paper describes the caudal-to-cranial surgical approach combined with complete mesocolic excision (CME) and D3 lymph node dissection, which may potentially reduce the technical difficulty and appear to be a safe approach. https://www.jove.com/v/69484 406 2026-01-09T22:20:00+00:00 JoVE no https://visualize.jove.com/7220655-angina-like-pain-an-unexpected-side-effect-following-the-simultaneous-administration-of-angiotensin-ii-and-prostaglandin-e2-in-normal-adults monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15044.jpg Antianginal Drugs: Nitrates and β-Blockers In cardiovascular health, antianginal drugs combat angina pectoris — a condition marked by chest pain owing to diminished blood flow to the heart. Organic nitrates, such as nitroglycerin, play a pivotal role. Once metabolized, they liberate nitric oxide, a molecular marvel. Nitric oxide triggers guanylyl cyclase and augments cGMP production. This biochemical cascade orchestrates the relaxation of vascular smooth muscles, ushering in vasodilation and enhancing coronary blood flow. Administered... https://www.jove.com/v/15044 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15364.jpg Treatment for Pulmonary Arterial Hypertension: Prostacyclin Receptor Agonists Prostacyclin receptor agonists are a class of therapeutic agents integral to managing pulmonary arterial hypertension (PAH). These drugs operate by mimicking the action of prostaglandin I2, or PGI2, a naturally occurring compound in the body. These agonists bind to the IPR receptor situated on the plasma membrane of the pulmonary artery smooth muscle cells. This binding triggers a cascade of reactions known as the GS-AC-cAMP-PKA pathway. This pathway results in the relaxation of smooth muscle... https://www.jove.com/v/15364 83 JoVE no https://cloudfront.jove.com/files/ftp_upload/17933/17933_article_thumb_17933.jpg Angina I: Introduction Definition and Symptoms: Angina (angina pectoris) is chest pain or discomfort caused by myocardial ischemia, which occurs when the heart muscle receives insufficient oxygen-rich blood. It typically manifests as pressing, squeezing, or crushing sensations in the chest and may radiate to the shoulders, arms, neck, jaw, or back.Primary Cause: In a healthy state, the coronary arteries can dilate (widen) to increase blood flow and meet the increased oxygen demand during physical activity or... https://www.jove.com/v/17933 90 2025-06-19T16:33:51+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17934/17934_article_thumb_17934.jpg Angina II: Classification Angina, also known as angina pectoris, is a chest pain resulting from diminished blood flow to the heart muscle and is often a symptom of coronary artery disease. Angina presents several variants with distinctive attributes, etiologies, and therapeutic approaches. The main types of angina include stable, unstable, variant (Prinzmetal's), microvascular, intractable, and silent ischemia.Stable angina is caused by atherosclerosis, which leads to the formation of plaques that narrow the coronary... https://www.jove.com/v/17934 87 2025-06-19T16:34:12+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17935/17935_article_thumb_17935.jpg Angina III: Clinical Manifestations and Assessment Angina manifests as chest pain, tightness, or squeezing discomfort typically located behind the breastbone. It can radiate to the neck, jaw, shoulders, and inner aspects of the upper arms, most commonly the left arm. Patients may experience shortness of breath, fatigue, profuse sweating, dizziness, indigestion, heartburn, palpitations, anxiety, and vomiting as accompanying symptoms. This pain often lasts a few minutes and is triggered by physical exertion, emotional stress, heavy meals, or cold... https://www.jove.com/v/17935 89 2025-06-19T16:34:32+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17937/17937_article_thumb_17937.jpg Angina V: Nursing Management Angina, a symptom of myocardial ischemia, requires a structured nursing management approach to ensure effective care and prevent complications like myocardial infarction. Comprehensive nursing care involves assessing, diagnosing, planning, implementing interventions, and evaluating outcomes, all tailored to the individual patient's needs.Patient AssessmentNursing assessment begins with a detailed subjective evaluation of symptoms, which typically include chest pain or pressure radiating to the... https://www.jove.com/v/17937 80 2025-06-19T16:35:07+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53191.jpg Subcutaneous Angiotensin II Infusion using Osmotic Pumps Induces Aortic Aneurysms in Mice Subcutaneous implantation of osmotic pumps provides a convenient approach for prolonged and consistent delivery of compounds. This approach has been used extensively to study both abdominal and thoracic aortic aneurysms in mice. https://www.jove.com/v/53191 441 2015-09-28T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54295.jpg Intracoronary Acetylcholine Provocation Testing for Assessment of Coronary Vasomotor Disorders Intracoronary acetylcholine testing has been established for the assessment of epicardial coronary spasm more than 30 years ago. Recently, the focus has shifted towards the microcirculation and it has been shown that microvascular spasm can be detected using ACH-testing. This article describes the ACH-test and its implementation in daily routine. https://www.jove.com/v/54295 399 2016-08-18T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62406.jpg Acetylcholine Re-Challenge After Intracoronary Nitroglycerine Administration This protocol presents the acetylcholine rechallenge after nitroglycerine as an add-on procedure to spasm provocation testing. The purpose of this technique is to unmask co-existing microvascular spasm in patients with epicardial spasm and to assess the protective efficacy of nitroglycerine on a per-patient level to guide medical therapy. https://www.jove.com/v/62406 479 2022-04-04T20:00:00+00:00 JoVE no https://visualize.jove.com/7359894-a-flexible-signal-averaging-system-for-cardiac-waveforms monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13286.jpg Pulse rhythm Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding. Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle... https://www.jove.com/v/13286 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15083.jpg Instrumentation Amplifier An electrocardiography (ECG) machine is an essential piece of medical equipment used to monitor the electrical activity of the heart. It operates by detecting small electrical changes on the skin that result from the depolarization of the heart muscle during each heartbeat. However, these signals are in the microvolt range and can be easily overwhelmed by noise or interference. To overcome this challenge, an ECG machine utilizes an instrumentation amplifier. This specialized amplifier is... https://www.jove.com/v/15083 85 2025-07-11T14:24:08+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15273.jpg Electrocardiogram An electrocardiogram (ECG or EKG) is a critical diagnostic tool that records the electrical signals produced by the heart during each heartbeat. This recording is achieved through electrodes placed strategically on the arms, legs, and chest. The electrocardiograph amplifies these signals and produces 12 distinct tracings, offering a comprehensive understanding of the heart's electrical activity. Three major waveforms are present in a typical ECG recording: the P wave, the QRS complex, and the T... https://www.jove.com/v/15273 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15275.jpg Correlation between ECG and Cardiac Cycle The electrical signals recorded on an electrocardiogram (ECG) occur before the mechanical processes of contraction and relaxation during the cardiac cycle. A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before... https://www.jove.com/v/15275 85 2025-05-15T16:16:28+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57089.jpg 2D and 3D Echocardiography in the Axolotl ( Ambystoma Mexicanum ) Here we present echocardiography protocols for two-dimensional and three-dimensional image acquisition of the beating heart of the axolotl salamander (Ambystoma mexicanum), a model species in heart regeneration. These methods allow for longitudinal evaluation of cardiac function at a high spatiotemporal resolution. https://www.jove.com/v/57089 593 2018-11-29T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59663.jpg High-Throughput Analysis of Optical Mapping Data Using ElectroMap This protocol describes the setup and use of ElectroMap, a MATLAB-based open-source software platform for analysis of cardiac optical mapping data. ElectroMap provides a versatile high-throughput tool for analysis of optical mapping voltage and calcium datasets across a wide range of cardiac experimental models. https://www.jove.com/v/59663 456 2019-06-04T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67958.jpg Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System This study introduces a novel approach for real-time cardiac mapping using a noninvasive, imageless electrocardiographic imaging system. This system enables the acquisition of electrophysiological cardiac maps without requiring pre-procedural computed tomography or magnetic resonance imaging scans, enabling efficient guidance for cardiac procedures such as ablation and cardiac resynchronization therapy implants. https://www.jove.com/v/67958 617 2025-04-11T21:20:00+00:00 JoVE no https://visualize.jove.com/7374173-an-improved-apparatus-for-intragastric-titration-in-the-conscious-dog monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/50301.jpg Assessment of Gastric Emptying in Non-obese Diabetic Mice Using a [ 13 C]-octanoic Acid Breath Test Determination of gastric emptying with a non-invasive [13C]-octanoic acid breath test for tracking gastroparesis in female NOD LtJ mice. https://www.jove.com/v/50301 744 2013-03-23T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51739.jpg Fabrication and Implantation of Miniature Dual-element Strain Gages for Measuring In Vivo Gastrointestinal Contractions in Rodents. The in vivo measurement of smooth muscle contractions along the gastrointestinal tract of laboratory animals remains a powerful, though underutilized, technique. Flexible, dual element strain gages are not commercially available and require fabrication. This protocol describes the construction of reliable, inexpensive strain gages for acute or chronic implantation in rodents. https://www.jove.com/v/51739 569 2014-09-18T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60953.jpg Sucrose Preference and Novelty-Induced Hypophagia Tests in Rats using an Automated Food Intake Monitoring System Presented here is a protocol to study depression-like and anhedonic behavior in rats. It combines two well-established behavioral methods, the sucrose preference and novelty-induced hypophagia tests, with an automated food and liquid intake monitoring system, to indirectly investigate rodent behavior using surrogate parameters. https://www.jove.com/v/60953 453 2020-05-08T20:00:00+00:00 JoVE no https://visualize.jove.com/7439329-studies-of-the-behaviour-of-isolated-cells-in-an-open-system monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12157.jpg Non-equilibrium in the Cell An important concept in studying metabolism and energy is that of chemical equilibrium. Most chemical reactions are reversible. They can proceed in both directions, releasing energy into their environment in one direction, and absorbing it from the environment in the other direction. The same is true for the chemical reactions involved in cell metabolism, such as the breaking down and building up of proteins into and from individual amino acids, respectively. Reactants within a closed system... https://www.jove.com/v/12157 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12546.jpg Entropy within the Cell A living cell's primary tasks of obtaining, transforming, and using energy to do work may seem simple. However, the second law of thermodynamics explains why these tasks are harder than they appear. None of the energy transfers in the universe are completely efficient. In every energy transfer, some amount of energy is lost in a form that is unusable. In most cases, this form is heat energy. Thermodynamically, heat energy is defined as the energy transferred from one system to another that is... https://www.jove.com/v/12546 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13371.jpg Overview Of Cell Separation And Isolation Cell separation was first achieved in 1964 by S. H. Seal, who separated large tumor cells from the smaller blood cells using filtration. Two years later, Pohl and Hawk performed experiments on how cells respond differently to a nonuniform electric field based on the cell type. Such observations were the inception of cell separation methods, which allow isolating a single cell type from a heterogeneous sample. Commonly used cell separation techniques include filtration, density gradient... https://www.jove.com/v/13371 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13674.jpg Thermodynamic Systems A thermodynamic system is a set of objects whose thermodynamic properties are of interest. The system is considered to be embedded in its surroundings or the environment. The system and its environment can exchange heat and do work on each other through a boundary that separates them. However, the immediate surroundings of the system interact with it directly and therefore have a much stronger influence on its behavior and properties. Consider an example of tea boiling in a kettle. The tea and... https://www.jove.com/v/13674 66 JoVE no https://cloudfront.jove.com/files/ftp_upload/15737/15737_article_thumb_15737.jpg System, Surroundings, and State Thermodynamics studies the relationship between heat, work, temperature, and energy. A key concept in this field is a "system," the macroscopic part of the universe under observation. Systems can interact with their surroundings, leading to three types: open, closed, and isolated systems.Open systems permit the exchange of both matter and energy with their surroundings, like a boiling pot of water.In contrast, closed systems only allow the transfer of energy, restricting the movement of matter... https://www.jove.com/v/15737 84 2026-02-26T21:04:55+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19511/19511_article_thumb_19511.jpg Techniques for Isolation of Pure Cultures Microorganisms are routinely cultured in the laboratory using various techniques to isolate, grow, and quantify them for further study. These methods rely on inoculating microorganisms into a suitable growth medium under aseptic conditions to prevent contamination. Depending on the objective, inoculation can involve direct transfer or the use of diluted bacterial suspensions as the inoculum.Streak-Plate Method for IsolationThe streak-plate method is a common technique for obtaining pure... https://www.jove.com/v/19511 84 2025-06-12T16:41:06+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50168.jpg The Use of Chemostats in Microbial Systems Biology Cell growth rate is a regulated process and a primary determinant of cell physiology. Continuous culturing using chemostats enables extrinsic control of cell growth rate by nutrient limitation facilitating the study of molecular networks that control cell growth and how those networks evolve to optimize cell growth. https://www.jove.com/v/50168 799 2013-10-15T03:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52616.jpg Sealable Femtoliter Chamber Arrays for Cell-free Biology A microfabricated device with sealable femtoliter-volume reaction chambers is described. This report includes a protocol for sealing cell-free protein synthesis reactants inside these chambers for the purpose of understanding the role of crowding and confinement in gene expression. https://www.jove.com/v/52616 824 2015-03-11T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56901.jpg Single-cell Microfluidic Analysis of Bacillus subtilis We present a method for the microfluidic analysis of individual bacterial cell lineages using Bacillus subtilis as an example. The method overcomes shortcomings of traditional analytical methods in microbiology by allowing observation of hundreds of cell generations under tightly controllable and uniform growth conditions. https://www.jove.com/v/56901 637 2018-01-26T22:30:00+00:00 JoVE no https://visualize.jove.com/7475117-a-mathematical-framework-for-describing-and-analysing-gene-regulatory-networks monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2703.jpg Using SCOPE to Identify Potential Regulatory Motifs in Coregulated Genes A straight-forward and robust method to identify potential regulatory motifs in co-regulated genes is presented. SCOPE does not require any user parameters and returns motifs that represent excellent candidates for regulatory signals. The identification of such regulatory signals helps to understand the underlying biology. https://www.jove.com/v/2703 475 2011-05-31T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11607.jpg Cis-regulatory Sequences Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are... https://www.jove.com/v/11607 122 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12229.jpg Epistasis Analysis Although Mendel chose seven unrelated traits in peas to study gene segregation, most traits involve multiple gene interactions that create a spectrum of phenotypes. When the interaction of various genes or alleles at different locations influences a phenotype, this is called epistasis. Epistasis often involves one gene masking or interfering with the expression of another (antagonistic epistasis). Epistasis often occurs when different genes are part of the same biochemical pathway. The... https://www.jove.com/v/12229 69 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11607.jpg Cis-regulatory Sequences Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are... https://www.jove.com/v/13143 122 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13181.jpg Structure of a Gene A gene is the fundamental unit of heredity. Every individual has two copies of each gene, one inherited from each parent. Although most people contain the same genes, there is a small fraction that is slightly different amongst people. A gene with a small difference in its sequence of DNA bases forms different alleles, contributing to different phenotypes. However, only 1% of the DNA is composed of genes that encode proteins; the rest, 99% is non-coding DNA. This non-coding DNA performs... https://www.jove.com/v/13181 90 JoVE no https://cloudfront.jove.com/files/ftp_upload/19532/19532_article_thumb_19532.jpg Operon Model The operon model represents a fundamental mechanism of gene regulation in prokaryotes, enabling coordinated expression of genes involved in related metabolic or functional pathways. Operons consist of structural genes, a promoter, and an operator, with transcription regulated by repressors, activators, and small effector molecules.Structure and Function of OperonsAn operon is a cluster of structural genes transcribed together under the control of a single promoter. The promoter region... https://www.jove.com/v/19532 83 2025-06-12T16:14:08+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19537/19537_article_thumb_19537.jpg Global Regulatory Systems Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource... https://www.jove.com/v/19537 88 2025-06-12T16:15:04+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63084.jpg Inherent Dynamics Visualizer, an Interactive Application for Evaluating and Visualizing Outputs from a Gene Regulatory Network Inference Pipeline The Inherent Dynamics Visualizer is an interactive visualization package that connects to a gene regulatory network inference tool for enhanced, streamlined generation of functional network models. The visualizer can be used to make more informed decisions for parameterizing the inference tool, thus increasing confidence in the resulting models. https://www.jove.com/v/63084 644 2021-12-07T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66030.jpg Generating the Transcriptional Regulation View of Transcriptomic Features for Prediction Task and Dark Biomarker Detection on Small Datasets Here, we introduce a protocol for converting transcriptomic data into a mqTrans view, enabling the identification of dark biomarkers. While not differentially expressed in conventional transcriptomic analyses, these biomarkers exhibit differential expression in the mqTrans view. The approach serves as a complementary technique to traditional methods, unveiling previously overlooked biomarkers. https://www.jove.com/v/66030 217 2024-03-01T21:50:00+00:00 JoVE no https://visualize.jove.com/7487863-computer-modeling-of-adaptive-depression monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10847.jpg Long-term Depression Long-term depression, or LTD, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTD is the process of synaptic weakening that occurs over time between pre and postsynaptic neuronal connections. The synaptic weakening of LTD works in opposition to synaptic strengthening by long-term potentiation (LTP) and together are the main mechanisms that underlie learning and memory. Calcium Ion Concentration Mechanism If over time, all... https://www.jove.com/v/10847 65 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12186.jpg Long-term Depression Long-term depression, or LTD, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTD is the process of synaptic weakening that occurs over time between pre and postsynaptic neuronal connections. The synaptic weakening of LTD works in opposition to synaptic strengthening by long-term potentiation (LTP) and together are the main mechanisms that underlie learning and memory. Calcium Ion Concentration Mechanism If over time, all... https://www.jove.com/v/12186 63 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15198.jpg Depression: Overview Depression is a prevalent mental illness marked by persistent sadness and lack of interest in previously enjoyable activities. It can take several forms, including major depression, persistent depressive disorder, and bipolar I and II disorders. Symptoms range from emotional changes like chronic worry to physical changes like sleep disturbances and suicidal thoughts. From a neurobiological perspective, depression is believed to be triggered by abnormalities in the brain's prefrontal cortex,... https://www.jove.com/v/15198 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18610.jpg Depressive Disorders: MDD and Dysthymia Depressive disorders are a group of mental health conditions characterized by pervasive feelings of sadness, diminished pleasure in life, and a significant impact on daily functioning. These conditions are most prevalent in individuals during their 30s and affect women at twice the rate of men. Contrary to popular belief, younger individuals are generally more susceptible to these disorders than older adults. Two key types of depressive disorders include Major Depressive Disorder (MDD) and... https://www.jove.com/v/18610 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18627.jpg Modeling in Therapy Modeling, a key technique in therapy, uses observational learning to help clients acquire and practice new skills by watching therapists demonstrate desired behaviors. This approach, rooted in Albert Bandura's concept of vicarious learning, plays a significant role in therapeutic interventions for various psychological conditions, including social anxiety, ADHD, and depression. Participant Modeling Participant modeling involves therapists demonstrating calm and effective behaviors in situations... https://www.jove.com/v/18627 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/19602.jpg Depressive Disorders: Etiology Depressive disorders result from a complex interplay of biological, psychological, and sociocultural factors, each contributing uniquely to the development and persistence of the condition. Understanding these factors provides critical insight into the multifaceted nature of depression. Biological Factors in Depression Biological predispositions significantly influence the risk of developing depressive disorders. Genetic studies highlight the role of variations in the serotonin transporter... https://www.jove.com/v/19602 87 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52587.jpg The Forced Swim Test as a Model of Depressive-like Behavior This protocol describes the forced swim test, which is used for the study of depressive-like behavior in rodents. This procedure involves placing an animal in a container filled with water that eventually will lead to the exhibition of immobility behavior, which is considered to reflect behavioral despair. https://www.jove.com/v/52587 342 2015-03-02T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62579.jpg Animal Models of Depression - Chronic Despair Model (CDM) The chronic despair mouse model (CDM) of depression consists of repetitive forced swim sessions and another delayed swim phase as a read-out. It represents a suitable model for induction of a chronic depressive-like state stable for at least 4 weeks, amendable to evaluate subchronic and acute treatment interventions. https://www.jove.com/v/62579 347 2021-09-23T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65889.jpg Chronic Unpredictable Mild Stress in Rats based on the Mongolian medicine This protocol outlines a chronic unpredictable mild stress (CUMS) model for depression based on Mongolian medical theory, along with methods for validating behavioral tests. https://www.jove.com/v/65889 356 2023-10-27T21:55:00+00:00 JoVE no https://visualize.jove.com/7488708-scaling-of-efficiency-in-programmable-and-non-programmable-systems monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15150.jpg Scaling In designing and analyzing filters, resonant circuits, or circuit analysis at large, working with standard element values like 1 ohm, 1 henry, or 1 farad can be convenient before scaling these values to more realistic figures. This approach is widely utilized by not employing realistic element values in numerous examples and problems; it simplifies mastering circuit analysis through convenient component values. The complexity of calculations is thereby reduced, with the understanding that... https://www.jove.com/v/15150 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12608.jpg Introduction to Scalers Many familiar physical quantities can be specified completely by giving a single number and the appropriate unit. For example, "a class period lasts 50 min," or "the gas tank in my car holds 65 L," or "the distance between the two posts is 100 m." A physical quantity that can be specified completely in this manner is called a scalar quantity. The word "scalar" is a synonym for "number." Time, mass, distance, length, volume, temperature, and energy are some examples of scalar quantities. Scalar... https://www.jove.com/v/15555 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16031.jpg Control Systems Control systems are everywhere in contemporary society, influencing diverse applications from aerospace to automated manufacturing. These systems can be found naturally within biological processes, such as blood sugar regulation and heart rate adjustment in response to stress, as well as in man-made systems like elevators and automated vehicles. A control system is essentially a network of subsystems and processes that collaboratively convert specific inputs into desired outputs. At the heart... https://www.jove.com/v/16031 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16094.jpg Feedback control systems Feedback control systems are categorized in various ways based on their design, analysis, and signal types. Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity... https://www.jove.com/v/16094 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16125.jpg Controller Configurations Controller configurations are crucial in a car's cruise control system because they manage speed over time to maintain a consistent pace regardless of road conditions, thereby meeting design goals. In traditional control systems, fixed-configuration design involves predetermined controller placement. System performance modifications are known as compensation. Control-system compensation involves various configurations, most commonly series or cascade compensation, in which the controller aligns... https://www.jove.com/v/16125 82 JoVE no https://cloudfront.jove.com/files/ftp_upload/40776/40776_article_thumb_40776.jpg Scale-Up Processes The scale-up of microbial fermentation processes is essential in industrial biotechnology, allowing the transition from laboratory-scale experiments to commercial-scale production while aiming to maintain product yield and quality. This process requires meticulous adjustment of equipment design, process parameters, and contamination control strategies to accommodate increasing culture volumes.At the laboratory scale, cultures are typically maintained in 1 to 10-liter glass or autoclavable... https://www.jove.com/v/40776 74 2026-03-12T20:57:33+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56422.jpg The Modular Design and Production of an Intelligent Robot Based on a Closed-Loop Control Strategy We present a protocol on modular design and production of intelligent robots to help scientific and technical workers design intelligent robots with special production tasks based on personal needs and individualized design. https://www.jove.com/v/56422 713 2017-10-14T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64930.jpg Large Scale Energy Efficient Sensor Network Routing Using a Quantum Processor Unit This study provides a method to use a quantum processor unit to compute the routes for various traffic dynamics that work to outperform classical methods in literature to maximize network lifetime. https://www.jove.com/v/64930 330 2023-09-08T21:35:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68888.jpg Simulation of a Scaled Assembly Process with Collaboration of a Robotic Arm and Monitoring through a Vision System for Quality Control Here, we present a protocol for the simulation and monitoring of a scaled semi-automated assembly process, through the collaboration of a collaborative robot and verification via a computer vision system for quality control. https://www.jove.com/v/68888 347 2025-08-29T21:45:00+00:00 JoVE no https://visualize.jove.com/7516545-differentiation-of-beats-of-ventricular-and-sinus-origin-using-a-self-training-neural-network monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15706.jpg Neural Control of Respiration The neural regulation of respiration is a meticulously coordinated process primarily controlled by the respiratory centers located within the brainstem. These centers, composed of specialized neurons, transmit nerve impulses that control the contraction and relaxation of our respiratory muscles. Respiratory Centers in the Brainstem Two primary areas comprise the respiratory center: the medullary respiratory center in the medulla oblongata and the pontine respiratory group in the pons. The... https://www.jove.com/v/15706 78 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50125.jpg Patient-specific Modeling of the Heart: Estimation of Ventricular Fiber Orientations A methodology to estimate ventricular fiber orientations from in vivo images of patient heart geometries for personalized modeling is described. Validation of the methodology performed using normal and failing canine hearts demonstrate that that there are no significant differences between estimated and acquired fiber orientations at a clinically observable level. https://www.jove.com/v/50125 729 2013-01-08T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65829.jpg BrainBeats as an Open-Source EEGLAB Plugin to Jointly Analyze EEG and Cardiovascular Signals The BrainBeats toolbox is an open-source EEGLAB plugin designed to jointly analyze EEG and cardiovascular (ECG/PPG) signals. It includes heartbeat-evoked potentials (HEP) assessment, feature-based analysis, and heart artifact extraction from EEG signals. The protocol will aid in studying brain-heart interplay through two lenses (HEP and features), enhancing reproducibility and accessibility. https://www.jove.com/v/65829 502 2024-04-26T19:40:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65931.jpg Artificial Intelligence-Based System for Detecting Attention Levels in Students This paper proposes an artificial intelligence-based system to automatically detect whether students are paying attention to the class or are distracted. This system is designed to help teachers maintain students' attention, optimize their lessons, and dynamically introduce modifications in order for them to be more engaging. https://www.jove.com/v/65931 397 2023-12-15T22:10:00+00:00 JoVE no https://visualize.jove.com/7528139-the-widespread-expression-of-angiogenin-in-different-human-cells-suggests-a-biological-function-not-only-related-to-angiogenesis monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3078.jpg Rat Mesentery Angiogenesis Assay Normal adult vascularized mammalian tissue that lacks physiologic angiogenesis and that has not been exposed to surgical intervention is used to study: (i) the initiation and development of angiogenesis following intraperitoneal administration of test agents; and (ii) modification of angiogenesis following systemic administration of selected test agents. https://www.jove.com/v/3078 1110 2011-06-18T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10716.jpg Paracrine Signaling Paracrine signaling allows cells to communicate with their immediate neighbors via secretion of signaling molecules. Such a signal can only trigger a response in nearby target cells because the signal molecules degrade quickly or are inactivated if not taken up. Prominent examples of paracrine signaling include nitric oxide signaling in blood vessels, synaptic signaling of neurons, the blood clotting system, tissue repair/wound healing, and local allergic skin reactions. Nitric oxide as a... https://www.jove.com/v/10716 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10719.jpg Endocrine Signaling Endocrine cells produce hormones to communicate with remote target cells found in other organs. The hormone reaches these distant areas using the circulatory system. This exposes the whole organism to the hormone but only those cells expressing hormone receptors or target cells are affected. Thus, endocrine signaling induces slow responses from its target cells but these effects also last longer. There are two types of endocrine receptors: cell surface receptors and intracellular receptors. https://www.jove.com/v/10719 105 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11605.jpg Cell Specific Gene Expression Multicellular organisms contain a variety of structurally and functionally distinct cell types, but the DNA in all the cells originated from the same parent cells. The differences in the cells can be attributed to the differential gene expression. Liver cells, whose functions include detoxification of blood, production of bile to metabolize fats, and synthesis of proteins essential for metabolism, must express a specific set of genes to perform their functions. Gene expression also varies with... https://www.jove.com/v/11605 118 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12509.jpg Mechanism of Angiogenesis Blood vessel formation starts early during embryonic development, around day 7. In the extraembryonic yolk sac, mesodermal precursor cells called hemangioblast proliferate and differentiate into angioblast. Angioblasts express vascular endothelial growth factor receptor 2 or VEGFR2, which binds VEGF-A, a proangiogenic factor, guiding blood vessel formation. VEGF signaling promotes angioblasts to form a blood island in the developing embryo. Angioblasts further differentiate, giving rise to... https://www.jove.com/v/12509 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12510.jpg Regulation of Angiogenesis and Blood Supply Rapidly dividing tumors, embryos, and wounded tissues require more oxygen than usual, lowering the oxygen concentration in the blood. At low oxygen or hypoxic conditions, an oxygen-sensitive transcription factor called the hypoxia-inducible factor 1 or HIF1 is activated. HIF1 is a dimeric protein of alpha (ɑ) and beta (β) subunits. Under optimal oxygen conditions, HIF1β is present in the nucleus while HIF1ɑ remains in the cytosol. HIF1ɑ is hydroxylated by prolyl hydroxylase and factor... https://www.jove.com/v/12510 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13347.jpg Overview of Cell-Matrix Interactions The extracellular matrix or ECM holds cells together to form a tissue and allows the cells within the tissue to communicate. ECM comprises proteins such as fibronectin, collagen, laminin, etc. The most abundant protein in this space is collagen. Collagen fibers are interwoven with carbohydrate-containing protein molecules called proteoglycans. ECM allows cell migration and provides a structural scaffold at cell adhesion that anchors the cell when the extracellular matrix proteins interact with... https://www.jove.com/v/13347 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60558.jpg In Vitro Model of Coronary Angiogenesis In vitro models of coronary angiogenesis can be utilized for the discovery of the cellular and molecular mechanisms of coronary angiogenesis. In vitro explant cultures of sinus venosus and endocardium tissues show robust growth in response to VEGF-A and display a similar pattern of COUP-TFII expression as in vivo. https://www.jove.com/v/60558 483 2020-03-10T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65567.jpg Modified In Vivo Matrix Gel Plug Assay for Angiogenesis Studies The method presented here can evaluate the effect of reagents on angiogenesis or vascular permeability in vivo without staining. The method uses dextran-FITC injection via the tail vein to visualize neo-vessels or vascular leakage. https://www.jove.com/v/65567 543 2023-06-30T21:15:00+00:00 JoVE no https://visualize.jove.com/7534238-internodal-cells-of-the-giant-green-alga-chara-as-an-expression-system-for-ion-channels monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2189.jpg Mutagenesis and Functional Analysis of Ion Channels Heterologously Expressed in Mammalian Cells We will demonstrate how to study the effect of a single point mutation on the function of an ion channel. https://www.jove.com/v/2189 928 2010-10-02T00:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10722.jpg Ion Channels The movement of ions like sodium, potassium, and calcium into and out of the cell is essential to maintain the electrochemical gradient in living cells. The ion channels—a class of membrane transport proteins—help maintain this ionic gradient for the smooth functioning of physiological activities such as maintaining cell size and volume, conducting nerve impulses, and gas and nutrient exchange. Ion channels are specialized integral membrane proteins on the plasma membrane that allow specific... https://www.jove.com/v/10722 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12179.jpg Channel Rhodopsins Most organisms use photoreceptors to sense and respond to light. Examples of photoreceptors include bacteriorhodopsins and bacteriophytochromes in some bacteria, phytochromes in plants, and rhodopsins in the photoreceptor cells of the vertebral retina. The light-sensitive property of these receptors is because of the bound chromophores, such as bilin in the phytochromes and retinal in the rhodopsins. Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,... https://www.jove.com/v/12179 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12244.jpg Ligand-gated Ion Channels Ligand-gated ion channels are transmembrane proteins with a channel for ions to pass through and a binding site for a ligand. The channel opens only when a ligand attaches to the binding site. Three Subfamilies of Ligand-gated Ion Channels Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that include the... https://www.jove.com/v/12244 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12246.jpg Mechanically-gated Ion Channels Mechanically-gated ion channels are proteins found in eukaryotic and prokaryotic cell membranes that open in response to mechanical stress. Tension, compression, swelling, and shear stress can alter the conformation of the protein, opening a transmembrane channel that allows the passage of ions for signal transmission. In eukaryotes, mechanically-gated channels are distributed in several regions like the neurons, lungs, skin, bladder, and heart, where they play critical roles in numerous... https://www.jove.com/v/12246 72 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13323.jpg G-Protein Gated Ion Channels GPCRs are primarily responsible for our sense of smell, taste, and vision. The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response. Sensory organs,... https://www.jove.com/v/13323 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12244.jpg Ligand-gated Ion Channels Ligand-gated ion channels are transmembrane proteins with a channel for ions to pass through and a binding site for a ligand. The channel opens only when a ligand attaches to the binding site. Three Subfamilies of Ligand-gated Ion Channels Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that include the... https://www.jove.com/v/14997 79 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51629.jpg One-channel Cell-attached Patch-clamp Recording Described here is a procedure for obtaining long stretches of current recording from one ion channel with the cell-attached patch-clamp technique. This method allows for observing, in real time, the pattern of open-close channel conformations that underlie the biological signal. These data inform about channel properties in undisturbed biological membranes. https://www.jove.com/v/51629 787 2014-06-09T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55497.jpg Whole-cell Patch-clamp Recordings for Electrophysiological Determination of Ion Selectivity in Channelrhodopsins This article describes how the ion selectivity of channelrhodopsin is determined with electrophysiological whole-cell patch-clamp recordings using HEK293 cells. Here, the experimental procedure for investigating chloride selectivity of an anion-selective channelrhodopsin is demonstrated. However, the procedure is transferable to other channelrhodopsins of distinct selectivity. https://www.jove.com/v/55497 519 2017-05-22T21:00:00+00:00 JoVE no https://visualize.jove.com/7539081-determinants-of-rna-hairpin-loop-loop-complex-stability monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10799.jpg RNA Structure Overview The basic structure of RNA consists of a five-carbon sugar and one of four nitrogenous bases. Although most RNA is single-stranded, it can form complex secondary and tertiary structures. Such structures play essential roles in the regulation of transcription and translation. Different Types of RNA Have the Same Basic Structure There are three main types of ribonucleic acid (RNA): messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three RNA types consist of a... https://www.jove.com/v/10799 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11009.jpg RNA Stability Intact DNA strands can be found in fossils, while scientists sometimes struggle to keep RNA intact under laboratory conditions. The structural variations between RNA and DNA underlie the differences in their stability and longevity. Because DNA is double-stranded, it is inherently more stable. The single-stranded structure of RNA is less stable but also more flexible and can form weak internal bonds. Additionally, most RNAs in the cell are relatively short, while DNA can be up to 250 million... https://www.jove.com/v/11009 113 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10799.jpg RNA Structure Overview The basic structure of RNA consists of a five-carbon sugar and one of four nitrogenous bases. Although most RNA is single-stranded, it can form complex secondary and tertiary structures. Such structures play essential roles in the regulation of transcription and translation. Different Types of RNA Have the Same Basic Structure There are three main types of ribonucleic acid (RNA): messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three RNA types consist of a... https://www.jove.com/v/11577 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11009.jpg RNA Stability Intact DNA strands can be found in fossils, while scientists sometimes struggle to keep RNA intact under laboratory conditions. The structural variations between RNA and DNA underlie the differences in their stability and longevity. Because DNA is double-stranded, it is inherently more stable. The single-stranded structure of RNA is less stable but also more flexible and can form weak internal bonds. Additionally, most RNAs in the cell are relatively short, while DNA can be up to 250 million... https://www.jove.com/v/11578 113 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11626.jpg mRNA Stability and Gene Expression The structure and stability of mRNA molecules regulates gene expression, as mRNAs are a key step in the pathway from gene to protein. In eukaryotes, the half-life of mRNA varies from a few minutes up to several days. mRNA stability is essential in growth and development. The absence of the proteins regulating its stability, such as tristetraprolin in mice, can cause systemic issues, including bone marrow overgrowth, inflammation, and autoimmunity. Cis-acting Elements involved in mRNA stability<br... https://www.jove.com/v/11626 171 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12556.jpg RNA Structure The basic structure of RNA consists of a string of ribonucleotides attached by phosphodiester bonds. Although most RNA is single-stranded, it can form complex secondary and tertiary structures. Such structures play essential roles in the regulation of transcription and translation. Different Types of RNA Have the Same Basic Structure There are three main types of ribonucleic acid (RNA) involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three... https://www.jove.com/v/12556 79 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51542.jpg Nanomanipulation of Single RNA Molecules by Optical Tweezers Optical tweezers have been used to study RNA folding by stretching individual molecules from their 5’ and 3’ ends. Here common procedures are described to synthesize RNA molecules for tweezing, calibration of the instrument, and methods to manipulate single molecules. https://www.jove.com/v/51542 419 2014-08-20T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62470.jpg Practical Aspects of Sample Preparation and Setup of 1 H R 1ρ Relaxation Dispersion Experiments of RNA We present a protocol to measure micro- to millisecond dynamics on 13C/15N-labeled and unlabeled RNA with 1H R1ρ relaxation dispersion nuclear magnetic resonance (NMR) spectroscopy. The focus of this protocol lies in high-purity sample preparation and setup of NMR experiments. https://www.jove.com/v/62470 497 2021-07-09T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62589.jpg Optical Tweezers to Study RNA-Protein Interactions in Translation Regulation This protocol presents a complete experimental workflow for studying RNA-protein interactions using optical tweezers. Several possible experimental setups are outlined including the combination of optical tweezers with confocal microscopy. https://www.jove.com/v/62589 746 2022-02-12T21:00:00+00:00 JoVE no https://visualize.jove.com/7573479-frequency-domain-of-renal-autoregulation-in-the-conscious-dog monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15301.jpg Neural Regulation of Blood Pressure The neural regulation of blood pressure involves intricate interactions between the autonomic nervous system (ANS) and cardiovascular system, ensuring adequate perfusion of tissues. This regulation primarily occurs through baroreceptor and chemoreceptor reflexes, involving both short-term and long-term mechanisms. Baroreceptor Reflex Baroreceptors, located in the carotid sinuses and aortic arch, detect changes in blood pressure. When blood pressure rises, these stretch-sensitive receptors... https://www.jove.com/v/15301 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15304.jpg Autoregulation of Blood Flow Autoregulation mechanisms are characterized by their inherent capacity for self-regulation without necessitating specific nervous stimulation or endocrine control. These mechanisms facilitate the adjustment of blood flow and, therefore, perfusion specific to each tissue region. This self-regulation encompasses chemical signals and myogenic controls. Chemical Signaling in Autoregulation Chemical signaling operates at the precapillary sphincter level, inciting either contraction or relaxation. https://www.jove.com/v/15304 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16251.jpg Glomerular Filtration Rate and its Regulation The Glomerular Filtration Rate (GFR) is a measure of kidney function, reflecting the volume of filtrate formed per minute in the kidneys. On average, GFR is approximately 125 mL/min in males and 105 mL/min in females. Maintaining a relatively constant GFR is essential for the kidneys to effectively regulate body fluid homeostasis and maintain extracellular stability. GFR regulation involves two primary intrinsic controls: the myogenic and tubuloglomerular feedback mechanisms. The myogenic... https://www.jove.com/v/16251 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16283.jpg Renal Regulation of Acid-Base Balance Metabolic reactions in the body produce nonvolatile acids, such as sulfuric acid, which generate an acid load of approximately 1 mEq of H+ per kilogram of body weight daily. Excreting H+ in the urine is essential to balance this acid load. In the kidneys, cells within the proximal convoluted tubules (PCT) and the collecting ducts secrete hydrogen ions (H+) into the tubular fluid. Specifically, in the PCT, Na+/H+ antiporters secrete H+ while reabsorbing Na+. However, the intercalated cells in... https://www.jove.com/v/16283 89 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53767.jpg Transcutaneous Assessment of Renal Function in Conscious Rodents Determination of glomerular filtration rate (GFR) is the gold standard to assess overall kidney function. However, traditional procedures to measure this parameter are cumbersome and require a large investment of time. Here we describe a faster and minimally invasive method to determinate GFR transcutaneously. https://www.jove.com/v/53767 438 2016-03-26T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60540.jpg Evaluation of Cerebral Blood Flow Autoregulation in the Rat Using Laser Doppler Flowmetry This article demonstrates the use of laser Doppler flowmetry to evaluate the ability of the cerebral circulation to autoregulate its blood flow during reductions in arterial blood pressure. https://www.jove.com/v/60540 432 2020-01-19T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63560.jpg Long-Term Continuous Measurement of Renal Blood Flow in Conscious Rats The present protocol describes a long-term continuous measurement of renal blood flow in conscious rats and simultaneously recording blood pressure with implanted catheters (fluid-filled or by telemetry). https://www.jove.com/v/63560 309 2022-02-08T23:00:00+00:00 JoVE no https://visualize.jove.com/7578479-nonlinear-neuronal-mode-analysis-of-action-potential-encoding-in-the-cockroach-tactile-spine-neuron monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2322.jpg Membrane Potentials, Synaptic Responses, Neuronal Circuitry, Neuromodulation and Muscle Histology Using the Crayfish: Student Laboratory Exercises The experiments demonstrate an easy approach for students to gain experience in examining muscle structure, synaptic responses, the effects of ion gradients and permeability on membrane potentials. Also, a sensory-CNS-motor-muscle circuit is presented to show a means to test effects of compounds on a neuronal circuit. https://www.jove.com/v/2322 976 2011-01-19T01:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10844.jpg Action Potentials Overview Neurons communicate by firing action potentials—the electrochemical signal that is propagated along the axon. The signal results in the release of neurotransmitters at axon terminals, thereby transmitting information in the nervous system. An action potential is a specific “all-or-none” change in membrane potential that results in a rapid spike in voltage. Membrane Potential in Neurons Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they... https://www.jove.com/v/10844 101 2025-10-23T18:47:13+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/12178/12178_article_thumb_Updated_12178.jpg Action Potential Neurons communicate by firing action potentials—the electrochemical signal that is propagated along the axon. The signal results in the release of neurotransmitters at axon terminals, thereby transmitting information to the nervous system. An action potential is a specific "all-or-none" change in membrane potential that results in a rapid spike in voltage. Membrane potential in neurons Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive... https://www.jove.com/v/12178 74 2025-08-28T22:01:35+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14884.jpg Functions of the Nervous System The nervous system is responsible for coordinating and regulating the body's functions. It functions through three main processes: sensory, integrative, and motor processes. Sensory function involves the detection and transmission of information about internal and external stimuli from sensory receptors to the CNS. The CNS processes this information through an integrative function, where it interprets and makes decisions based on the incoming sensory information. Finally, the motor function... https://www.jove.com/v/14884 78 JoVE no https://cloudfront.jove.com/files/ftp_upload/12178/12178_article_thumb_Updated_12178.jpg Action Potential Neurons communicate by firing action potentials—the electrochemical signal that is propagated along the axon. The signal results in the release of neurotransmitters at axon terminals, thereby transmitting information to the nervous system. An action potential is a specific "all-or-none" change in membrane potential that results in a rapid spike in voltage. Membrane potential in neurons Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive... https://www.jove.com/v/14892 74 2025-09-16T22:06:20+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14893.jpg Action Potential: Phases of Stimulation The action potential is a complex electrical event that occurs in excitable cells, such as neurons and muscle cells. It consists of several distinct phases, each with specific characteristics. Resting Phase: In this phase, the cell's membrane is at its resting potential, typically around -70 millivolts (mV) for neurons. Inside the cell, there is a higher concentration of potassium ions (K+) and a lower concentration of sodium ions (Na+). Voltage-gated sodium channels are closed, and... https://www.jove.com/v/14893 88 JoVE no https://cloudfront.jove.com/files/ftp_upload/14894/14894_article_thumb_14894.jpg Propagation of Action Potentials The propagation of an action potential refers to the process by which a nerve impulse, or "action potential," travels along a neuron. Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to... https://www.jove.com/v/14894 83 2025-08-11T22:39:58+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50584.jpg Neural Circuit Recording from an Intact Cockroach Nervous System This article describes the cockroach ventral nerve cord dissection and extracellular recordings from the cercal nerve and connectives. Evoked responses are generated by electrical stimulation of the cercal nerve or direct mechanical stimulation of the cerci. https://www.jove.com/v/50584 651 2013-11-05T04:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51337.jpg Extracellular Wire Tetrode Recording in Brain of Freely Walking Insects We previously developed a technique for implanting tetrode wires into the central complex of cockroach brains that allows us to monitor activity in individual units of tethered cockroaches. Here we present a modified version of that technique that allows us to also record brain activity in freely moving insects. https://www.jove.com/v/51337 928 2014-04-01T23:30:00+00:00 JoVE no https://visualize.jove.com/7584398-dna-sequence-analysis-using-hierarchical-art-based-classification-networks monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/11014/11014_article_thumb_11014.jpg Phylogenetic Trees Phylogenetic trees come in many forms. It matters in which sequence the organisms are arranged from the bottom to the top of the tree, but the branches can rotate at their nodes without altering the information. The lines connecting individual nodes can be straight, angled, or even curved.The length of the branches can depict time or the relative amount of change among organisms. For instance, the branch length might indicate the number of amino acid changes in the sequence that underlies the... https://www.jove.com/v/11014 201 2026-06-01T13:28:25+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11987.jpg Evolutionary Relationships through Genome Comparisons Genome comparison is one of the excellent ways to interpret the evolutionary relationships between organisms. The basic principle of genome comparison is that if two species share a common feature, it is likely encoded by the DNA sequence conserved between both species. The advent of genome sequencing technologies in the late 20th century enabled scientists to understand the concept of conservation of domains between species and helped them to deduce evolutionary relationships across diverse... https://www.jove.com/v/11987 174 JoVE no https://cloudfront.jove.com/files/ftp_upload/19557/19557_article_thumb_19557.jpg Modern Molecular Taxonomy Advancements in molecular biology have revolutionized the identification and characterization of bacteria, with multiple methods leveraging DNA sequencing for enhanced precision. As sequencing technologies improve and costs decline, these approaches are increasingly used in clinical, environmental, and evolutionary studies.Multilocus Sequence Typing (MLST) examines several housekeeping genes, essential chromosomal genes encoding cellular functions, to distinguish strains. Approximately... https://www.jove.com/v/19557 89 2025-06-12T16:19:23+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55133.jpg Large-scale Reconstructions and Independent, Unbiased Clustering Based on Morphological Metrics to Classify Neurons in Selective Populations This protocol describes large-scale reconstructions of selective neuronal populations, labeled following retrograde infection with a modified rabies virus expressing fluorescent markers, and independent, unbiased cluster analyses that enable comprehensive characterization of morphological metrics among distinct neuronal subclasses. https://www.jove.com/v/55133 747 2017-02-15T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56684.jpg Using Phylogenetic Analysis to Investigate Eukaryotic Gene Origin A method of constructing a phylogenetic tree based on sequence homology of SWEETs from eukaryotes and SemiSWEETs from prokaryotes is described. Phylogenetic analysis is a useful tool for explaining the evolutionary relatedness between homologous proteins or genes from different organism groups. https://www.jove.com/v/56684 537 2018-08-14T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62250.jpg A Virtual Machine Platform for Non-Computer Professionals for Using Deep Learning to Classify Biological Sequences of Metagenomic Data This tutorial describes a simple method to construct a deep learning algorithm for performing 2-class sequence classification of metagenomic data. https://www.jove.com/v/62250 574 2021-09-25T21:00:00+00:00 JoVE no https://visualize.jove.com/7597644-novel-strategies-to-an-auxin-evoked-transport-control monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11097.jpg Short-distance Transport of Resources Short-distance transport refers to transport that occurs over a distance of just 2-3 cells, crossing the plasma membrane in the process. Small uncharged molecules, such as oxygen, carbon dioxide, and water, can diffuse across the plasma membrane on their own. In contrast, ions and larger molecules require the assistance of transport proteins due to their charge or size. Transport across membranes also occurs within individual cells, playing a variety of essential roles for the plant as a whole.<br... https://www.jove.com/v/11097 132 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11114.jpg Plant Hormones Plant hormones—or phytohormones—are chemical molecules that modulate one or more physiological processes of a plant. In animals, hormones are often produced in specific glands and circulated via the circulatory system. However, plants lack hormone-producing glands. Instead, plant hormones are often produced in regions of active growth, like the tips of roots and shoots. Additionally, even very low concentrations of plant hormones can have a profound effect on growth and development processes. https://www.jove.com/v/11114 116 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12818.jpg Protein Transport to the Thylakoids Thylakoids are membrane-bound sac-like structures within the chloroplast that serve as sites for photosynthesis. Thylakoid lumen contains many electron transport proteins and is enclosed by a thylakoid membrane rich in the light-harvesting complex. Proteins targeted to the thylakoids are transported as precursors and are sorted by the general TOC/TIC import pathway. Once the precursor reaches the stroma, stromal processing peptidases remove their transit signal and expose thylakoid signal... https://www.jove.com/v/12818 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14397.jpg Drug Absorption Mechanism: Carrier-Mediated Membrane Transport Certain large, lipid-insoluble drug molecules that resemble amino acids, peptides, or glucose, require specialized carrier proteins to facilitate their diffusion across cell membranes. This transport can occur through either facilitated diffusion, which does not require energy input, or active transport, which does require energy input. Facilitated diffusion is a passive process that utilizes human Solute Carrier (SLC) transporters. These transporters bind to the drug, undergo structural... https://www.jove.com/v/14397 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16495.jpg Carrier-Mediated Transport Carrier-mediated transport is a pivotal process in drug absorption, particularly for lipid-insoluble drugs, and encompasses facilitated diffusion and active transport. Facilitated diffusion allows drugs to move along their concentration gradient without energy expenditure, while active transport utilizes ATP to drive drug movement against this gradient. Active transport involves two types of membrane-spanning transporters: uptake and efflux. Uptake transporters are expressed in the small... https://www.jove.com/v/16495 66 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16497.jpg Active Transport Active transport is a critical biological process that allows cells to move solutes against an electrochemical gradient. This process requires direct energy input and is characterized by its selectivity, saturability, and susceptibility to competitive inhibition. Primary active transporters, like Na+, K+ and -ATPase, directly utilize ATP to move ions across the membrane. These transporters play significant roles in various physiological processes. For instance, Na+, K+ and -ATPase maintain... https://www.jove.com/v/16497 74 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53481.jpg Lateral Root Inducible System in Arabidopsis and Maize The Lateral Root Inducible System (LRIS) allows for synchronous induction of lateral roots and is presented for Arabidopsis thaliana and maize. https://www.jove.com/v/53481 563 2016-01-15T00:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53513.jpg A Strategy to Validate the Role of Callose-mediated Plasmodesmal Gating in the Tropic Response This article describes the methods for screening the genes controlling plasmodesmal permeability and hence auxin gradient during tropic response. This includes the measurement of the degree of tropic response in hypocotyl of Arabidopsis thaliana and checking plasmodesmal permeability by 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) loading and finally callose level assessment. https://www.jove.com/v/53513 738 2016-04-17T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65194.jpg Direct Infusion Device for Molecule Delivery in Plants This manuscript describes a novel direct plant infusion device for screening the effectiveness of molecules against the bacteria (Candidatus Liberibacter asiaticus) or its insect vector (Diaphorina citri, Kuwayama) that, in combination, are associated with Huanglongbing citrus disease. https://www.jove.com/v/65194 532 2023-06-02T21:30:00+00:00 JoVE no https://visualize.jove.com/7665504-the-c-terminal-region-of-the-alpha-subunit-of-escherichia-coli-rna-polymerase-is-required-for-transcriptional-activation-of-the-flagellar-level-ii-operons-by-the-flhdflhc-complex monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4110.jpg High-throughput Purification of Affinity-tagged Recombinant Proteins We describe a method for the affinity-tagged purification of recombinant proteins using liquid-handling robotics. This method is generally applicable to the small-scale purification of soluble His-tagged proteins in a high-throughput format. https://www.jove.com/v/4110 464 2012-08-26T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11579.jpg Bacterial RNA Polymerase Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity. In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize... https://www.jove.com/v/11579 43 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11584.jpg RNA Polymerase II Accessory Proteins Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in... https://www.jove.com/v/11584 156 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11613.jpg Eukaryotic Transcription Activators Transcription activators are proteins that promote the transcription of genes from DNA to RNA. In most cases, these proteins contain two separate domains ‒ a domain that binds to DNA and a domain for activating transcription; however, in some cases, a single domain is responsible for both binding and activation of transcription, as seen in the glucocorticoid receptor and MyoD. The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These domains are... https://www.jove.com/v/11613 162 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11579.jpg Bacterial RNA Polymerase Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity. In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize... https://www.jove.com/v/12559 43 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12561.jpg General Transcription Factors Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of... https://www.jove.com/v/12561 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11584.jpg RNA Polymerase II Accessory Proteins Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in... https://www.jove.com/v/12562 156 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52431.jpg The Multifaceted Benefits of Protein Co-expression in Escherichia coli Protein co-expression is a powerful alternative to the reconstitution in vitro of protein complexes, and is of help in performing biochemical and genetic tests in vivo. Here we report on the use of protein co-expression in Escherichia coli to obtain protein complexes, and to tune the mutation frequency of cells. https://www.jove.com/v/52431 768 2015-02-05T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59497.jpg Artificial RNA Polymerase II Elongation Complexes for Dissecting Co-transcriptional RNA Processing Events Here, we describe the assembly of RNA polymerase II (Pol II) elongation complexes requiring only short synthetic DNA and RNA oligonucleotides and purified Pol II. These complexes are useful for studying mechanisms underlying co-transcriptional processing of transcripts associated with the Pol II elongation complex. https://www.jove.com/v/59497 659 2019-05-13T21:00:00+00:00 JoVE no https://visualize.jove.com/7680045-characteristics-of-dna-replication-in-isolated-nuclei-initiated-by-an-aprotinin-binding-protein monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1919.jpg Direct Restart of a Replication Fork Stalled by a Head-On RNA Polymerase The fate of the replisome following a collision with a head-on RNA polymerase (RNAP) is unknown. We find that the replisome stalls upon collision with a head-on RNAP, but resumes elongation after displacing the RNAP from DNA. Mfd promotes replication restart by facilitating displacement of the RNAP after the collision. https://www.jove.com/v/1919 447 2010-04-30T00:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10788.jpg Replication in Prokaryotes Overview DNA replication has three main steps: initiation, elongation, and termination. Replication in prokaryotes begins when initiator proteins bind to the single origin of replication (ori) on the cell’s circular chromosome. Replication then proceeds around the entire circle of the chromosome in each direction from two replication forks, resulting in two DNA molecules. Many Proteins Work Together to Replicate the Chromosome Replication is coordinated and carried out by a host of... https://www.jove.com/v/10788 155 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10789.jpg Replication in Eukaryotes Overview In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus. Many Proteins Orchestrate Replication at the Origin Eukaryotic replication follows many of the... https://www.jove.com/v/10789 151 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11548.jpg The DNA Replication Fork An organism’s genome needs to be duplicated in an efficient and error-free manner for its growth and survival. The replication fork is a Y-shaped active region where two strands of DNA are separated and replicated continuously. The coupling of DNA unzipping and complementary strand synthesis is a characteristic feature of a replication fork. Organisms with small circular DNA, such as E. coli, often have a single origin of replication; therefore, they have only two replication forks, one in... https://www.jove.com/v/11548 62 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11568.jpg Restarting Stalled Replication Forks DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a... https://www.jove.com/v/11568 157 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13195.jpg Replication in Prokaryotes DNA replication has three main steps: initiation, elongation, and termination. Replication in prokaryotes begins when initiator proteins bind to the single origin of replication (ori) on the cell's circular chromosome. Replication then proceeds around the entire circle of the chromosome in each direction from the two replication forks, resulting in two DNA molecules. Many Proteins Work Together to Replicate the Chromosome Replication is coordinated and carried out by a host of specialized... https://www.jove.com/v/13195 92 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13196.jpg Replication in Eukaryotes In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fulfill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus. Many Proteins Orchestrate Replication at the Origin Eukaryotic replication follows many of the same... https://www.jove.com/v/13196 89 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54434.jpg Inducing a Site Specific Replication Blockage in E. coli Using a Fluorescent Repressor Operator System We describe here a system utilizing a site-specific, reversible in vivo protein block to stall and collapse replication forks in Escherichia coli. The establishment of the replication block is evaluated by fluorescence microscopy and neutral-neutral 2-dimensional agarose gel electrophoresis is used to visualize replication intermediates. https://www.jove.com/v/54434 679 2016-08-21T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67229.jpg Electrophoretic Analysis of Replication Through Structure-Prone DNA Repeats Within the SV40-Based Human Episome Here, we outline the procedure for analyzing replication progression through pathogenic, structure-prone repeats using 2-dimensional gel electrophoresis. https://www.jove.com/v/67229 322 2024-09-13T22:00:00+00:00 JoVE no https://visualize.jove.com/7703343-realtime-measurement-of-stroke-volume-an-adaptive-monitoring-system-and-its-application monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13311.jpg Equipments Used To Measure Blood Pressure Direct Method This invasive approach involves cannulating a peripheral artery. During each cardiac contraction, pressure generates mechanical motion within the catheter, transmitted through rigid, fluid-filled tubing to a transducer. This transducer converts mechanical motion into electrical signals displayed as waveforms on a monitor. An automatic flushing system prevents blood backflow. Due to the potential risk of unexpected arterial blood loss, this method is primarily used in intensive... https://www.jove.com/v/13311 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13316.jpg Assessing Blood pressure using a doppler ultrasound To obtain accurate blood pressure measurements in clinical settings, especially when traditional methods are insufficient, healthcare professionals utilize the Doppler ultrasound technique. This method uses high-frequency sound waves to detect blood flow within the arteries, which is crucial for patients with conditions that complicate circulatory system assessment. Pre-Procedural Guidelines for Doppler Ultrasound Blood Pressure Assessment: Preparation of Equipment: • Assemble the necessary... https://www.jove.com/v/13316 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15278.jpg Cardiac Output and Stroke Volume Cardiac output (CO) is an integral aspect of human physiology, reflecting the heart's efficiency and responsiveness to the body's needs. It represents the volume of blood that the left or right ventricle ejects into the aorta or pulmonary trunk each minute. The CO is calculated by multiplying the heart rate (HR)—the number of heartbeats per minute—by the stroke volume (SV)—the amount of blood pumped out with each heartbeat. In an average resting adult male, the typical cardiac output averages... https://www.jove.com/v/15278 71 2025-05-15T16:17:33+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15279.jpg Regulation of Stroke Volume The regulation of stroke volume, which is the amount of blood the heart pumps out during each heartbeat, is critical for maintaining a healthy circulatory system. Stroke volume is influenced by three main factors: preload, contractility, and afterload. Preload refers to the degree of stretch on the heart before it contracts. It's analogous to the stretching of a rubber band; the more it's stretched, the more forcefully it snaps back. This concept is encapsulated in the Frank-Starling law of the... https://www.jove.com/v/15279 87 2025-05-15T16:18:04+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15296.jpg Measurement of Blood Pressure Assessing blood pressure is a standard procedure executed in virtually all medical environments. The method utilized today was established over a hundred years ago by an innovative Russian doctor, Dr. Nikolai Korotkoff. The soft ticking noise, known as Korotkoff sounds, heard while taking blood pressure readings results from turbulent blood flow within the vessels. The apparatus required for this procedure includes a sphygmomanometer, a blood pressure cuff attached to a gauge, and a stethoscope. https://www.jove.com/v/15296 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17866.jpg Cardiac Output II: Effect of Stroke Volume on Cardiac Output Cardiac output (CO), the amount of blood the heart pumps per minute, is a parameter in cardiovascular physiology determined by stroke volume and heart rate. Stroke volume, the amount of blood pushed from one of the ventricles per heartbeat, is influenced by preload, afterload, and contractility. Preload Preload refers to the initial elongation of the cardiac myocytes before contraction and is related to the volume of blood filling the heart at the end of diastole, or end-diastolic volume. The... https://www.jove.com/v/17866 82 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50214.jpg Optimized System for Cerebral Perfusion Monitoring in the Rat Stroke Model of Intraluminal Middle Cerebral Artery Occlusion Cerebral perfusion monitoring has been demonstrated to improve accuracy in ischemic stroke models. Technical difficulties often limit the use of this essential tool for cerebrovascular research. In this video, an optimized system is shown to obtain a single or multi-site hemodynamic monitoring during intraluminal middle cerebral artery occlusion in rats. https://www.jove.com/v/50214 735 2013-02-17T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64410.jpg Continuous Venous-Arterial Doppler Ultrasound During a Preload Challenge The Frank-Starling-Sarnoff curve is clinically important and describes the relationship between cardiac preload and output. This report illustrates a novel method of simultaneous jugular venous and carotid arterial Doppler velocimetry as transient surrogates of cardiac preload and output, respectively; this approach is enabled by wireless, wearable Doppler ultrasound. https://www.jove.com/v/64410 572 2023-01-20T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64672.jpg Real-Time Monitoring and Modulation of Blood Pressure in a Rabbit Model of Ischemic Stroke Continuous arterial blood pressure recording allows the investigation of impacts of various hemodynamic parameters. This report demonstrates the application of continuous arterial blood pressure monitoring in a large animal model of ischemic stroke for determination of stroke pathophysiology, impact of different hemodynamic factors, and the assessment of novel treatment approaches. https://www.jove.com/v/64672 540 2023-02-10T21:15:00+00:00 JoVE no https://visualize.jove.com/7711997-statistical-tools-for-understanding-variation-the-allocation-of-operating-suite-time monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13220.jpg Standard Deviation The most commonly used measure of variation is the standard deviation. It is a numerical value measuring how far data values are from their mean. The standard deviation value is small when the data are concentrated close to the mean, exhibiting slight variation or spread. The standard deviation value is never negative, it is either positive or zero. The standard deviation is larger when the data values are more spread out from the mean, which means the data values are exhibiting more... https://www.jove.com/v/13220 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13223.jpg Variance The deviations show how spread out the data are about the mean. A positive deviation occurs when the data value exceeds the mean, whereas a negative deviation occurs when the data value is less than the mean. If the deviations are added, the sum is always zero. So one cannot simply add the deviations to get the data spread. By squaring the deviations, the numbers are made positive; thus, their sum will also be positive.The standard deviation measures the spread in the same units as the data. https://www.jove.com/v/13223 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13573.jpg Probability Histograms A probability histogram is a visual representation of a probability distribution. Similar a typical histogram, the probability histogram consists of contiguous (adjoining) boxes. It has both a horizontal axis and a vertical axis. The horizontal axis is labeled with what the data represents. The vertical axis is labeled with probability. Each rectangular bar in the histogram is 1 unit wide, which suggests that the area under each bar equals the probability, P(x), where x is 1, 2, 3, and so on. https://www.jove.com/v/13573 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16478.jpg Variability: Analysis Measures of variability are statistical metrics that reveal the dispersion pattern within a dataset. They are pivotal in biostatistics, providing insights into the heterogeneity within health and biological data. Variability signifies the degree to which data points diverge from one another, helping researchers understand the potential range of values and associated uncertainty within the data. The range is a simple measure of variability, indicating the difference between the highest and... https://www.jove.com/v/16478 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17634.jpg Introduction to Statistical Process Control Statistical Process Control (SPC) is a method used to monitor and control quality within processes, particularly in manufacturing and service delivery, by employing statistical methods. SPC aims to distinguish between natural (common cause) variation and variation due to specific changes or events (special cause), allowing for timely improvements and sustained quality. The control chart, a pivotal tool in SPC, visually displays data over time alongside a central line of upper and lower control... https://www.jove.com/v/17634 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17636.jpg Interpreting Run Charts Run charts, essentially line graphs plotted over time, serve as fundamental yet effective tools for process analysis. They chronicle data sequentially, facilitating the identification of trends, shifts, or cyclical movements. This graphical representation is instrumental in determining whether a process is stable or exhibits signs of potential instability indicative of special cause variation. In the healthcare domain, run charts depict infection rates over time, enabling hospitals to monitor... https://www.jove.com/v/17636 85 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59742.jpg Split Point Analysis and Uncertainty Quantification of Thermal-Optical Organic/Elemental Carbon Measurements This article presents a protocol and software tool for the quantification of uncertainties in the calibration and data analysis of a semi-continuous thermal-optical organic/elemental carbon analyzer. https://www.jove.com/v/59742 622 2019-09-07T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65076.jpg Design and Optimization Strategies of a High-Performance Vented Box Here, we present the range analysis method to optimize the sample points generated by an orthogonal experimental design to ensure that fresh food can be stored in a vented box for a long time by regulating the airflow pattern. https://www.jove.com/v/65076 863 2023-06-09T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68868.jpg A User-friendly and Powerful R Analysis of Large-scale Datasets This report describes a method involving an R script in the open-source software RStudio to analyze large-scale datasets obtained from time series experiments. https://www.jove.com/v/68868 656 2025-11-04T21:30:00+00:00 JoVE no https://visualize.jove.com/7783226-an-operational-rna-code-for-amino-acids-and-variations-in-critical-nucleotide-sequences-in-evolution monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10798.jpg The Central Dogma Overview The central dogma of biology states that information encoded in the DNA is transferred to messenger RNA (mRNA), which then directs the synthesis of protein. The set of instructions that enable the mRNA nucleotide sequence to be decoded into amino acids is called the genetic code. The universal nature of this genetic code has spurred advances in scientific research, agriculture, and medicine. RNA Is the Missing Link between DNA and Proteins In the early 1900s, scientists discovered... https://www.jove.com/v/10798 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11476.jpg From DNA to Protein The flow of genetic information in cells from DNA to mRNA to protein is described by the central dogma, which states that genes specify the sequence of mRNAs, which in turn specify the sequence of amino acids making up all proteins. The decoding of one molecule to another is performed by specific proteins and RNAs. Because the information stored in DNA is so central to cellular function, it makes intuitive sense that the cell would make mRNA copies of this information for protein synthesis... https://www.jove.com/v/11476 186 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11484.jpg Gene Evolution - Fast or Slow? The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain crucial regulatory sequences, the vast majority of this DNA serves no known function. Typically, these regions of the genome are the ones in which the fastest change, in evolutionary terms, is observed, because there is typically little to no selection pressure acting on these regions to preserve their sequences. In contrast, regions which code... https://www.jove.com/v/11484 125 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11595.jpg tRNA Activation Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the... https://www.jove.com/v/11595 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12442.jpg The Central Dogma The central dogma explains the flow of genetic information from DNA nucleotides to the amino acid sequence of proteins. RNA is the Missing Link Between DNA and Proteins In the early 1900s, scientists discovered that DNA stores all the information needed for cellular functions and that proteins perform most of these functions. However, the mechanisms of converting genetic information into functional proteins remained unknown for many years. Initially, it was believed that a single gene is... https://www.jove.com/v/12442 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11595.jpg tRNA Activation Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the... https://www.jove.com/v/13132 146 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54273.jpg Residue-specific Incorporation of Noncanonical Amino Acids into Model Proteins Using an Escherichia coli Cell-free Transcription-translation System An easy-to-use, cell-free expression protocol for the residue-specific incorporation of noncanonical amino acid analogs into proteins, including downstream analysis, is presented for medical, pharmaceutic, structural and functional studies. https://www.jove.com/v/54273 707 2016-08-01T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57061.jpg A Facile Protocol to Generate Site-Specifically Acetylated Proteins in Escherichia Coli Genetic code expansion serves as a powerful tool to study a wide range of biological processes, including protein acetylation. Here we demonstrate a facile protocol to exploit this technique for generating homogeneously acetylated proteins at specific sites in Escherichia coli cells. https://www.jove.com/v/57061 668 2017-12-09T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59331.jpg Identifying Amino Acid Overproducers Using Rare-Codon-Rich Markers This study presents an alternative strategy to the conventional toxic analog-based method in identifying amino acid overproducers by using rare-codon-rich markers to achieve accuracy, sensitivity, and high-throughput simultaneously. https://www.jove.com/v/59331 641 2019-06-24T20:30:00+00:00 JoVE no https://visualize.jove.com/7798700-clinical-results-of-selective-cerebral-perfusion-during-reconstruction-of-the-transverse-aortic-arch monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/62047.jpg Real-Time Assessment of Spinal Cord Microperfusion in a Porcine Model of Ischemia/Reperfusion Spinal cord microcirculation plays a pivotal role in spinal cord injury. Most methods do not allow real-time assessment of spinal cord microcirculation, which is essential for the development of microcirculation-targeted therapies. Here, we propose a protocol using Laser-Doppler-Flow Needle probes in a large animal model of ischemia/reperfusion. https://www.jove.com/v/62047 627 2020-12-10T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67060.jpg A Modified Model Preparation for Middle Cerebral Artery Occlusion Reperfusion This protocol describes the process of preparing for middle cerebral artery occlusion reperfusion via the common carotid artery. https://www.jove.com/v/67060 258 2024-05-31T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68033.jpg Novel and Innovative Hybrid Technique for Type A Aortic Dissection The protocol describes ascending aortic replacement combined with endovascular coverage of the entire aortic arch with a fenestrated stent graft in a patient with acute type A aortic dissection in the absence of a tear in the aortic arch. https://www.jove.com/v/68033 386 2025-03-28T21:55:00+00:00 JoVE no https://visualize.jove.com/7811230-vitamin-a-regulates-the-expression-of-apolipoprotein-ai-and-ciii-genes-in-the-rat monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11605.jpg Cell Specific Gene Expression Multicellular organisms contain a variety of structurally and functionally distinct cell types, but the DNA in all the cells originated from the same parent cells. The differences in the cells can be attributed to the differential gene expression. Liver cells, whose functions include detoxification of blood, production of bile to metabolize fats, and synthesis of proteins essential for metabolism, must express a specific set of genes to perform their functions. Gene expression also varies with... https://www.jove.com/v/11605 118 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11623.jpg RNA Editing RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or modification. The extent of RNA editing varies from a few hundred bases, in mitochondrial DNA of trypanosomes, to a just single base, in nuclear genes of mammals. Even a single base change in the pre-mRNA can convert a codon for one amino acid into the codon for another amino acid or a stop codon. This type of re-coding can significantly affect the... https://www.jove.com/v/11623 143 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11939.jpg Regulation of Nuclear Protein Sorting Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the... https://www.jove.com/v/11939 105 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12510.jpg Regulation of Angiogenesis and Blood Supply Rapidly dividing tumors, embryos, and wounded tissues require more oxygen than usual, lowering the oxygen concentration in the blood. At low oxygen or hypoxic conditions, an oxygen-sensitive transcription factor called the hypoxia-inducible factor 1 or HIF1 is activated. HIF1 is a dimeric protein of alpha (ɑ) and beta (β) subunits. Under optimal oxygen conditions, HIF1β is present in the nucleus while HIF1ɑ remains in the cytosol. HIF1ɑ is hydroxylated by prolyl hydroxylase and factor... https://www.jove.com/v/12510 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13898.jpg Lipid-derived Compounds in the Human Body Fats and lipids are crucial components in the human body. Some lipid-derived compounds, such as fat-soluble vitamins, eicosanoids, lipoproteins, and glycolipids, also play unique roles to support various biological processes . Fat-soluble Vitamins Fat-soluble vitamins, including vitamins A, D, E, and K, are required in minimal quantities, but their deficiencies can lead to severely abnormal physiological conditions. For example, vitamin A deficiency can cause night blindness, dry skin, delayed... https://www.jove.com/v/13898 91 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50957.jpg Production of Apolipoprotein C-III Knockout Rabbits using Zinc Finger Nucleases Recent development in gene targeting tools makes production of knockout (KO) rabbits possible. In the present work, we generated five Apolipoprotein (Apo) C-III KO rabbits using Zinc Finger Nucleases (ZFN). This work demonstrated that ZFN is a highly efficient method to produce KO rabbits. https://www.jove.com/v/50957 659 2013-11-19T05:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59828.jpg Quantification of Atherosclerosis in Mice Murine models of atherosclerosis are useful tools to investigate pathogenic pathways on a molecular level, but require standardized quantification of lesion development. This protocol describes an optimized method to determine lesion size in the major arterial vessels including the aortic root, aortic arch, and brachiocephalic artery. https://www.jove.com/v/59828 419 2019-06-12T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61790.jpg Isolation and Analysis of Plasma Lipoproteins by Ultracentrifugation Several methods have been used for analyzing plasma lipoproteins; however, ultracentrifugation is still one of the most popular and reliable methods. Here, we describe a method regarding how to isolate lipoproteins from plasma using sequential density ultracentrifugation and how to analyze the apolipoproteins for both diagnostic and research purposes. https://www.jove.com/v/61790 407 2021-01-28T23:00:00+00:00 JoVE no https://visualize.jove.com/7824685-training-redundant-artificial-neural-networks-imposing-biology-on-technology monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10835.jpg Neural Regulation Digestion begins with a cephalic phase that prepares the digestive system to receive food. When our brain processes visual or olfactory information about food, it triggers impulses in the cranial nerves innervating the salivary glands and stomach to prepare for food. The cephalic phase is a conditioned or learned response to familiar foods. Our appetite or desire for a particular food modifies the preparatory responses directed by the brain. Individuals may produce more saliva and stomach... https://www.jove.com/v/10835 97 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12037.jpg Synthetic Biology Synthetic biology is an interdisciplinary science that involves using principles from disciplines such as engineering, molecular biology, cell biology, and systems biology. It involves remodeling existing organisms from nature or constructing completely new synthetic organisms for applications such as protein or enzyme production, bioremediation, value-added macromolecule production, and the addition of desirable traits to crops, to name a few. Golden rice Golden rice is a genetically modified... https://www.jove.com/v/12037 175 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12157.jpg Non-equilibrium in the Cell An important concept in studying metabolism and energy is that of chemical equilibrium. Most chemical reactions are reversible. They can proceed in both directions, releasing energy into their environment in one direction, and absorbing it from the environment in the other direction. The same is true for the chemical reactions involved in cell metabolism, such as the breaking down and building up of proteins into and from individual amino acids, respectively. Reactants within a closed system... https://www.jove.com/v/12157 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14900.jpg Neural Circuits Neural circuits and neuronal pools are two of the main structures found in the nervous system. Neural circuits are networks of neurons that work together to carry out a specific task or process. They consist of interconnected neurons and glial cells, which provide structural and metabolic support. Neuronal pools are collections of nerve cells with similar functions and interact through chemical and electrical signals. These pools include both interneurons (the central neural circuit nodes that... https://www.jove.com/v/14900 85 2025-06-13T01:07:11+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17745.jpg Neuroplasticity Neuroplasticity reflects the brain's remarkable capacity to adapt and evolve, responding dynamically to learning, experiences, or injury by reorganizing its neural circuitry. This reorganization involves creating new neural connections and refining old ones through a series of biological processes that contribute to the brain's lifelong development and adaptability. • The brain's ability to change begins with the growth of dendrites and axons, which effectively increases the structural... https://www.jove.com/v/17745 61 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52341.jpg Closed-loop Neuro-robotic Experiments to Test Computational Properties of Neuronal Networks In this paper, an experimental framework to perform closed-loop experiments is presented, in which information processing (i.e., coding and decoding) and learning of neuronal assemblies are studied during the continuous interaction with a robotic body. https://www.jove.com/v/52341 678 2015-03-02T06:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55609.jpg Anatomically Inspired Three-dimensional Micro-tissue Engineered Neural Networks for Nervous System Reconstruction, Modulation, and Modeling This manuscript details the fabrication of micro-tissue engineered neural networks: three-dimensional micron-sized constructs comprised of long aligned axonal tracts spanning aggregated neuronal population(s) encased in a tubular hydrogel. These living scaffolds can serve as functional relays to reconstruct or modulate neural circuitry or as biofidelic test-beds mimicking gray-white matter neuroanatomy. https://www.jove.com/v/55609 645 2017-05-31T06:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62250.jpg A Virtual Machine Platform for Non-Computer Professionals for Using Deep Learning to Classify Biological Sequences of Metagenomic Data This tutorial describes a simple method to construct a deep learning algorithm for performing 2-class sequence classification of metagenomic data. https://www.jove.com/v/62250 574 2021-09-25T06:00:00+00:00 JoVE no https://visualize.jove.com/7830694-casemix-an-ama-perspective monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11402.jpg Mixtures of Acids The pH of a solution containing an acid can be determined using its acid dissociation constant and its initial concentration. If a solution contains two different acids, then its pH can be determined using one of several methods depending upon the relative strength of the acids and their dissociation constants. A Mixture of a Strong Acid and a Weak Acid In a mixture of a strong acid and a weak acid, the strong acid dissociates completely and becomes a source of almost all the hydronium ions... https://www.jove.com/v/11402 207 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11727.jpg Racemic Mixtures and the Resolution of Enantiomers A racemic mixture, or racemate, is an equimolar mixture of enantiomers of a molecule that can be separated using their unique interaction with chiral molecules or media. Racemic mixtures are denoted by the (±)- prefix. This ‘optical rotation descriptor’ applies to the whole solution of a racemic mixture rather than a specific stereoisomer. Enantiomers typically have the same physical and chemical properties. Hence, they are not easily separable. However, enantiomers can exhibit different... https://www.jove.com/v/11727 150 JoVE no https://cloudfront.jove.com/files/ftp_upload/15774/15774_article_thumb_15774.png Ideal Solutions or Mixtures From a molecular perspective, an ideal solution is one in which the intermolecular interactions between unlike molecules are, on average, the same as those between like molecules. This is the case for ideal gas mixtures, where the molecules are far apart and do not interact with each other. However, for condensed phases like liquids or solids, the molecules are close together and interact with each other. In an ideal solution, the molecules of different species are so similar to each other that... https://www.jove.com/v/15774 80 2026-02-26T21:04:41+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16907.jpg Mixing Concrete Concrete mixing ensures a homogenous blend where aggregates are well-coated with cement paste. Concrete mixing is typically done using two main types of mixers: batch and continuous. Batch mixers handle one batch at a time, thoroughly combining materials before discharging and receiving the next batch. In contrast, continuous mixers receive a steady flow of ingredients, mixing them consistently and discharging without interruption. Within batch mixers, tilting drum mixers mix with internal... https://www.jove.com/v/16907 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16908.jpg Mixing Time The concept of mixing time is significant in producing a uniform concrete mix with the required strength. The mixing period starts once all components are in the mixer. Initially, the mixer is charged with 10% of the water, followed by the consistent addition of solids and then 80% of the water. The remaining water is added later, within the first quarter of the mixing period. The minimum mixing time varies according to the mixer's capacity; for example, mixers with up to 1 cubic yard capacity... https://www.jove.com/v/16908 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17362.jpg Mixtures of Acids The pH of a solution containing an acid can be determined using its acid dissociation constant and initial concentration. If a solution contains two different acids, then its pH can be determined using one of several methods depending on the relative strength of the acids and their dissociation constants. In a strong and weak acid mixture, the strong acid dissociates completely and becomes a source of almost all the hydronium ions present in the solution. In contrast, the weak acid shows... https://www.jove.com/v/17362 79 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58957.jpg Using Microarrays to Interrogate Microenvironmental Impact on Cellular Phenotypes in Cancer The purpose of the method presented here is to show how microenvironment microarrays (MEMA) can be fabricated and used to interrogate the impact of thousands of simple combinatorial microenvironments on the phenotype of cultured cells. https://www.jove.com/v/58957 500 2019-05-21T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60035.jpg Applying an eMASS Customization Program as a Research Tool to Evaluate Consumer Benefits Presented here is a protocol to examine consumer responses toward mass customization in the context of online retailing. The protocol details the online survey procedure and how to analyze data using structural equation modeling and group differences using latent mean analyses. https://www.jove.com/v/60035 507 2019-09-27T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65845.jpg A Synthetic Methodology for Preparing Impregnated and Grafted Amine-Based Silica Composites for Carbon Capture This work aims to facilitate the development of standardized techniques for impregnating or grafting aminated compounds onto silica substrates, which are often broadly described in the literature. Specific amounts of solvent, substrate, amines, and the values of other important experimental parameters will be discussed in detail. https://www.jove.com/v/65845 480 2023-09-29T21:40:00+00:00 JoVE no https://visualize.jove.com/7838712-trinucleotide-phosphoramidites-ideal-reagents-for-the-synthesis-of-mixed-oligonucleotides-for-random-mutagenesis monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11575.jpg Conservative Site-specific Recombination and Phase Variation Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines. The recognition sites for Cre recombinase called LoxP... https://www.jove.com/v/11575 173 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12228.jpg Maxam-Gilbert Sequencing In the same year as the discovery of the Sanger sequencing method, another group of scientists, Allan Maxam and Walter Gilbert, demonstrated their chemical-cleavage method for DNA sequencing. The Maxam-Gilbert method relies on using different chemicals that can cleave the DNA sequence at specific sites, the separation of resulting DNA fragments of variable size using electrophoresis, and deciphering the DNA sequence from the resulting gel bands. Challenges of the Maxam-Gilbert Method The... https://www.jove.com/v/12228 65 JoVE no https://cloudfront.jove.com/files/ftp_upload/19544/19544_article_thumb_19544.jpg Spontaneous and Induced Mutations Spontaneous mutations arise infrequently during DNA replication due to errors in the process. A key factor behind these errors is tautomeric shifts in nitrogenous bases, where bases transition from keto to enol forms or amino to imino forms. This shift can alter base-pairing rules, leading to mutations. Additionally, reactive oxygen species (ROS) arising from aerobic metabolism can damage DNA, resulting in depurination (loss of a purine base) or depyrimidination (loss of a pyrimidine base). https://www.jove.com/v/19544 90 2025-06-12T16:16:54+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51385.jpg Nucleoside Triphosphates - From Synthesis to Biochemical Characterization The protocol described herein aims to explain and abridge the numerous obstacles in the way of the intricate route leading to modified nucleoside triphosphates. Consequently, this protocol facilitates both the synthesis of these activated building-blocks and their availability for practical applications. https://www.jove.com/v/51385 922 2014-04-03T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60807.jpg In Vitro Directed Evolution of a Restriction Endonuclease with More Stringent Specificity Restriction endonucleases with new sequence specificity can be developed from enzymes recognizing a partially degenerate sequence. Here we provide a detailed protocol that we successfully used to alter the sequence specificity of NlaIV enzyme. Key ingredients of the protocol are the in vitro compartmentalization of the transcription/translation reaction and selection of variants with new sequence specificities. https://www.jove.com/v/60807 556 2020-03-25T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63877.jpg Chemical Triphosphorylation of Oligonucleotides Oligonucleotide 5′-triphosphates are ubiquitous components in essential biological pathways and have seen increasing use in biotechnology applications. Here, we describe techniques for the routine synthesis and purification of oligonucleotide 5′-triphosphates, starting from oligonucleotides prepared by standard automated synthesis techniques. https://www.jove.com/v/63877 799 2022-06-02T20:40:00+00:00 JoVE no https://visualize.jove.com/7845794-adjusting-heart-rate-during-sleep-using-activity-variance monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13284.jpg Decreased pulse rate Bradycardia is a medical condition in which the heart rate is slower than normal. It occurs when the heart's natural pacemaker, the sinus node, generates slower electrical impulses than the standard rhythm. In adults, bradycardia is diagnosed when the pulse rate falls below 60 beats per minute, indicating a deviation from the normal heart rate range. There are specific risk factors that can elevate the likelihood of developing bradycardia. Advanced age is a significant factor, with bradycardia... https://www.jove.com/v/13284 74 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13286.jpg Pulse rhythm Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding. Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle... https://www.jove.com/v/13286 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13288.jpg Factors Influencing Heart Rate The heart rate, or pulse rate, is a vital indicator of cardiovascular health. It reflects the number of times the heart beats per minute. Various physiological and environmental factors influence heart rate, increasing or decreasing cardiac output. Understanding these factors is crucial for assessing heart function and identifying potential health issues. Let us explore the significant factors affecting heart rate, including age, body temperature, posture, acute pain, chemical influences,... https://www.jove.com/v/13288 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15276.jpg Disturbances in Heart Rhythm Arrhythmia or dysrhythmia refers to an abnormal heart rhythm caused by a defect in the heart's conduction system. It can cause the heart to beat irregularly, too quickly, or too slowly, leading to symptoms like chest pain, shortness of breath, and fainting. Factors such as stress, caffeine, alcohol, nicotine, cocaine, certain drugs, congenital defects, diseases, and electrolyte abnormalities can trigger arrhythmias. Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart... https://www.jove.com/v/15276 89 2025-07-29T16:29:05+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15280.jpg Regulation of Heart Rates The regulation of heart rate is a complex process controlled by the autonomic nervous system (ANS), hormonal influences, and intrinsic cardiac mechanisms. The ANS has two main components: the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). The SNS increases heart rate through the release of norepinephrine and epinephrine, which act on beta-1 adrenergic receptors in the heart. This action increases the rate of depolarization in the sinoatrial (SA) node, the heart's... https://www.jove.com/v/15280 91 2025-05-15T16:18:44+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17865.jpg Cardiac Output I:Effect of Heart Rate on Cardiac Output Cardiac Output Cardiac output (CO) refers to the total amount of blood ejected by one of the ventricles in liters per minute (L/min). In a resting adult, CO ranges from 5 to 6 L/min, adjusting according to the body's metabolic requirements. Effect of Heart Rate on Cardiac Output Cardiac output adapts to metabolic demands during stress, physical activity, or illness. The autonomic nervous system regulates heart rate via the sinoatrial node. The parasympathetic nervous system decreases heart rate... https://www.jove.com/v/17865 79 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55863.jpg Quantifying Infra-slow Dynamics of Spectral Power and Heart Rate in Sleeping Mice Here, we present experimental and analytical procedures to describe the temporal dynamics of the neural and cardiac variables of non-REM sleep in mice, which modulate sleep responsiveness to acoustic stimuli. https://www.jove.com/v/55863 656 2017-08-02T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59230.jpg Calculating Heart Rate Variability from ECG Data from Youth with Cerebral Palsy During Active Video Game Sessions This protocol describes a method for calculating Heart Rate Variability (HRV) from electrocardiogram (ECG) waveforms. Waveforms from continuous heart rate (HR) recordings during active video game (AVG) sessions were used to measure the aerobic performance of youth with cerebral palsy (CP). https://www.jove.com/v/59230 492 2019-06-05T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67674.jpg Assessing the Accuracy of Fitness Smartwatch Data for Cardiovascular and Physical Activity Monitoring: A Validation Study in Digital Health Wearable technology has low cost and offers convenient monitoring of physiological data. However, the accuracy and reliability of these devices require cautious assessment to ensure their effectiveness and safety for users. This report describes the validation process of a commercial smartwatch in monitoring physiological data and physical activity. https://www.jove.com/v/67674 351 2025-02-21T21:40:00+00:00 JoVE no https://visualize.jove.com/7884353-automated-analysis-of-spontaneously-occurring-arrhythmias-by-implantable-devices-limitations-of-using-rate-and-timing-features-alone monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13286.jpg Pulse rhythm Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding. Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle... https://www.jove.com/v/13286 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15028.jpg Mechanism of Cardiac Arrhythmias Arrhythmias are irregular heart rhythms occurring when the heart's electrical impulses become abnormal. These disturbances can lead to various symptoms, depending on their severity and the underlying cause. Some common factors contributing to arrhythmias include hypoxia, ischemia, electrolyte imbalances, excessive catecholamine exposure, drug toxicity, and muscle overstretching. Arrhythmias can be classified into two main types based on the rate and site of origin of abnormal heart rhythms. https://www.jove.com/v/15028 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15276.jpg Disturbances in Heart Rhythm Arrhythmia or dysrhythmia refers to an abnormal heart rhythm caused by a defect in the heart's conduction system. It can cause the heart to beat irregularly, too quickly, or too slowly, leading to symptoms like chest pain, shortness of breath, and fainting. Factors such as stress, caffeine, alcohol, nicotine, cocaine, certain drugs, congenital defects, diseases, and electrolyte abnormalities can trigger arrhythmias. Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart... https://www.jove.com/v/15276 89 2025-07-29T16:29:05+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17887/17887_article_thumb_17887.jpg Holter Monitor: 24-Hour Monitoring Holter monitoring is a continuous electrocardiography (ECG) recording that tracks the heart's electrical activity over an extended period, generally 24 to 48 hours. This noninvasive diagnostic tool detects irregular heart rhythms that may not be captured during a standard ECG performed in a clinical setting.DeviceThe Holter monitor is a portable, small device connected to several electrodes on the patient's chest. These electrodes detect the heart's electrical signals and transmit them to the... https://www.jove.com/v/17887 83 2025-06-19T16:09:27+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17942/17942_article_thumb_17942.jpg Dysrhythmias V: Evaluating Dysrhythmias Dysrhythmias, also known as arrhythmias, are disturbances in the heart's rhythm that range from benign to life-threatening. A thorough evaluation is crucial for appropriate management and involves a comprehensive medical history, physical examination, and various diagnostic tests.Medical HistorySymptoms: Collect detailed information on palpitations, dizziness, syncope, chest pain, and fatigue. Note their onset, frequency, and triggers.Previous Cardiac Issues: Document any history of heart... https://www.jove.com/v/17942 90 2025-06-19T16:36:46+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18437/18437_article_thumb_18437.jpg ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias Arrhythmia is a condition characterized by an irregular heart rhythm, with ECG changes that differ based on its origin and nature. The types of arrhythmias discussed below include atrial, junctional, and ventricular arrhythmias.Atrial ArrhythmiasPremature Atrial Complexes (PACs): PACs are early atrial beats caused by stress, caffeine, alcohol, electrolyte imbalances, hypoxia, hyperthyroidism, or certain medications (e.g., bronchodilators and decongestants). The ECG shows early P waves with an... https://www.jove.com/v/18437 85 2025-06-19T16:15:27+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50124.jpg A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis Continuous 12-lead electrocardiographic (ECG) monitoring can identify transient myocardial ischemia, even when asymptomatic, among patients with suspected acute coronary syndrome (ACS). In this article we describe our method for initiating patient monitoring using a Holter device, downloading the ECG data for off-line analysis, and how to utilize the ECG software to identify transient ischemia. https://www.jove.com/v/50124 1091 2012-12-28T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62386.jpg Analyzing Long-Term Electrocardiography Recordings to Detect Arrhythmias in Mice Here we present a step-by-step protocol for a semiautomated approach to analyze murine long-term electrocardiography (ECG) data for basic ECG parameters and common arrhythmias. Data are obtained by implantable telemetry transmitters in living and awake mice and analyzed using Ponemah and its analysis modules. https://www.jove.com/v/62386 367 2021-05-23T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67958.jpg Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System This study introduces a novel approach for real-time cardiac mapping using a noninvasive, imageless electrocardiographic imaging system. This system enables the acquisition of electrophysiological cardiac maps without requiring pre-procedural computed tomography or magnetic resonance imaging scans, enabling efficient guidance for cardiac procedures such as ablation and cardiac resynchronization therapy implants. https://www.jove.com/v/67958 617 2025-04-11T21:20:00+00:00 JoVE no https://visualize.jove.com/7932099-roles-of-anions-in-cells-studies-on-a-cl-translocating-atpase-and-sulfate-uptake-system-in-acetabularia-acetabulum monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11877.jpg ATP Driven Pumps I: An Overview ATP-driven pumps, also known as transport ATPases, are integral membrane proteins. They have binding sites for ATP located on the membrane's cytosolic side and the ion-conducting domain in the transmembrane region. These pumps use the free energy released from ATP hydrolysis to move the solutes across cell membranes against an electrochemical gradient. There are four main types of ATP-driven pumps - P-type, V-type, F-type, and ABC transporter. All these pumps are of varying complexities and are... https://www.jove.com/v/11877 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11880.jpg Secondary Active Transport One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme "pump" embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of... https://www.jove.com/v/11880 92 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11901.jpg ATP Synthase: Mechanism In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP... https://www.jove.com/v/11901 108 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12218.jpg ATP Driven Pumps III: V-type Pumps V-type pumps are ATP-driven pumps found in the vacuolar membranes of plants, yeast, endosomal and lysosomal membranes of animal cells, plasma membranes of a few specialized eukaryotic cells, and some prokaryotes. They are also known as the V1Vo-ATPase, that couple ATP hydrolysis to transport protons against a concentration gradient. The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits... https://www.jove.com/v/12218 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16494.jpg Pore Transport and Ion-Pair Transport Pore transport and ion-pair formation are critical mechanisms for the absorption and distribution of drugs in the body. Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct microscopic... https://www.jove.com/v/16494 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16497.jpg Active Transport Active transport is a critical biological process that allows cells to move solutes against an electrochemical gradient. This process requires direct energy input and is characterized by its selectivity, saturability, and susceptibility to competitive inhibition. Primary active transporters, like Na+, K+ and -ATPase, directly utilize ATP to move ions across the membrane. These transporters play significant roles in various physiological processes. For instance, Na+, K+ and -ATPase maintain... https://www.jove.com/v/16497 74 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50201.jpg Measuring Cation Transport by Na,K- and H,K-ATPase in Xenopus Oocytes by Atomic Absorption Spectrophotometry: An Alternative to Radioisotope Assays We describe a method to quantify the activity of K+-countertransporting P-type ATPases by heterologous expression of the enzymes in Xenopus oocytes and measuring Rb+ or Li+ uptake into individual cells by atomic absorption spectrophotometry. The method is a sensitive and safe alternative to radioisotope flux experiments facilitating complex kinetic studies. https://www.jove.com/v/50201 768 2013-02-19T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59166.jpg Expression, Solubilization, and Purification of Eukaryotic Borate Transporters Here we present a protocol to express, solubilize, and purify several eukaryotic borate transporters with homology to the SLC4 transporter family using yeast. We also describe a chemical cross-linking assay to assess the purified homomeric proteins for multimeric assembly. These protocols can be adapted for other challenging membrane proteins. https://www.jove.com/v/59166 535 2019-03-07T23:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67748.jpg Purification of the Sarco-Endoplasmic Reticulum Ca 2+ -ATPase from Rabbit Muscle This protocol describes an improved SERCA purification method, which includes the disaccharide trehalose in the final centrifugation step. This carbohydrate stabilizes proteins under harsh conditions. The purified SERCA was catalytically active and displayed high purity, making it suitable for structural and functional studies. https://www.jove.com/v/67748 517 2025-03-21T21:00:00+00:00 JoVE no https://visualize.jove.com/8022677-mental-rotation-and-mirror-image-discrimination monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11719.jpg Chirality Chirality is a term that describes the lack of mirror symmetry in an object. In other words, chiral objects cannot be superposed on their mirror images. For example, our feet are chiral, as the mirror image of the left foot, the right foot, cannot be superposed on the left foot. Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have... https://www.jove.com/v/11719 145 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11721.jpg Stereoisomers On the basis of mirror symmetry, stereoisomers of an organic molecule can be further classified into diastereomers and enantiomers. Diastereomers are stereoisomers that are not mirror images of each other. Substituted alkenes, such as the cis and trans isomers of 2-butene, are diastereomers, as these molecules exhibit different spatial orientations of their constituent atoms, are not mirror images of each other, and do not interconvert. Here, the interconversion is suppressed due to restricted... https://www.jove.com/v/11721 152 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11724.jpg Properties of Enantiomers and Optical Activity It is essential to understand the difference between chiral and achiral interactions and the implications thereof in optical activity and their applications. Just as our feet, which are chiral, interact uniquely with chiral objects, such as a pair of shoes, but identically with achiral socks, enantiomers of a molecule exhibit different properties only when they interact with other chiral media. An example of a significant implication from this facet is the phenomenon known as optical activity,... https://www.jove.com/v/11724 144 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50877.jpg Measuring Sensitivity to Viewpoint Change with and without Stereoscopic Cues We discuss a novel method forviewpoint-rotation of visual stimuli, and demonstrate using a mirror stereoscopethe three-dimensional percept of rotation-in-depth. The technique can be used to investigate the role of stereoscopic cues in encoding viewpoint-rotated figures. https://www.jove.com/v/50877 484 2013-12-05T02:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59149.jpg Generating Strictly Controlled Stimuli for Figure Recognition Experiments This protocol describes a method for an experiment that examines whether specific graph and non-graph properties (features) are relevant to the recognition of figures. The method uses a database that stores various feature values of respective figures called (6 point, n line) figures. https://www.jove.com/v/59149 339 2019-03-18T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65977.jpg Three-Dimensional Mapping of the Rotation of Interactive Virtual Objects with Eye-Tracking Data We have developed a simple, customizable, and efficient method for recording quantitative processual data from interactive spatial tasks and mapping these rotation data with eye-tracking data. https://www.jove.com/v/65977 396 2024-10-18T19:30:00+00:00 JoVE no https://visualize.jove.com/8078919-the-alpha-subunit-of-the-nak-atpase-specifically-and-stably-associates-into-oligomers monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11506.jpg Protein Complex Assembly Proteins can form homomeric complexes with another unit of the same protein or heteromeric complexes with different types. Most protein complexes self-assemble spontaneously via ordered pathways, while some proteins need assembly factors that guide their proper assembly. Despite the crowded intracellular environment, proteins usually interact with their correct partners and form functional complexes. Many viruses self-assemble into a fully functional unit using the infected host cell to... https://www.jove.com/v/11506 161 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11901.jpg ATP Synthase: Mechanism In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP... https://www.jove.com/v/11901 108 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11904.jpg ATP Synthase: Structure ATP synthase or ATPase is among the most conserved proteins found in bacteria, mammals, and plants. This enzyme can catalyze a forward reaction in response to the electrochemical gradient, producing ATP from ADP and inorganic phosphate. ATP synthase can also work in a reverse direction by hydrolyzing ATP and generating an electrochemical gradient. Different forms of ATP synthases have evolved special features to meet the specific demands of the cell. Based on their specific feature, ATP... https://www.jove.com/v/11904 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11905.jpg The ADP/ATP Carrier Protein ADP/ATP carrier or AAC protein is the most abundant carrier protein in the inner mitochondrial membrane. It transports large quantities of ADP and ATP, equivalent to the average human body weight, every day. Among other transporters, ACC protein is one of the best-studied members of the mitochondrial carrier protein family. The ADP/ATP carrier protein comprises two transmembrane helices connected to a loop and a single alpha-helix on the matrix side. It switches between two conformational... https://www.jove.com/v/11905 102 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12218.jpg ATP Driven Pumps III: V-type Pumps V-type pumps are ATP-driven pumps found in the vacuolar membranes of plants, yeast, endosomal and lysosomal membranes of animal cells, plasma membranes of a few specialized eukaryotic cells, and some prokaryotes. They are also known as the V1Vo-ATPase, that couple ATP hydrolysis to transport protons against a concentration gradient. The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits... https://www.jove.com/v/12218 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12221.jpg Allosteric Proteins-ATCase Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor. Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,... https://www.jove.com/v/12221 79 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50201.jpg Measuring Cation Transport by Na,K- and H,K-ATPase in Xenopus Oocytes by Atomic Absorption Spectrophotometry: An Alternative to Radioisotope Assays We describe a method to quantify the activity of K+-countertransporting P-type ATPases by heterologous expression of the enzymes in Xenopus oocytes and measuring Rb+ or Li+ uptake into individual cells by atomic absorption spectrophotometry. The method is a sensitive and safe alternative to radioisotope flux experiments facilitating complex kinetic studies. https://www.jove.com/v/50201 768 2013-02-19T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51228.jpg Visualization of ATP Synthase Dimers in Mitochondria by Electron Cryo-tomography We present a protocol of how to collect and process electron cryo-tomograms of whole mitochondria. The technique provides detailed insights into the structure, function, and organization of large membrane protein complexes in native biological membranes. https://www.jove.com/v/51228 639 2014-09-14T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62770.jpg Chemical Modification of the Tryptophan Residue in a Recombinant Ca 2+ -ATPase N-domain for Studying Tryptophan-ANS FRET ANS binds to the Ca2+-ATPase recombinant N-domain. Fluorescence spectra display a FRET-like pattern upon excitation at a wavelength of 295 nm. NBS-mediated chemical modification of Trp quenches the fluorescence of the N-domain, which leads to the absence of energy transfer (FRET) between the Trp residue and ANS. https://www.jove.com/v/62770 727 2021-10-09T20:00:00+00:00 JoVE no https://visualize.jove.com/8094300-an-expanded-nomenclature-scheme-for-labeling-peptide-fragmentations-and-its-use-with-amass-a-computer-program-for-generating-all-possible-fragment-ion-structures-from-known-precursors monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12298.jpg Mass Spectrometry: Molecular Fragmentation Overview The ionization of a molecule into a molecular ion inside the mass spectrometer causes instability in the molecule's structure due to the loss of an electron. This eventually leads to the fragmentation or breaking of some bonds in the molecule. The fragmentation occurs predominantly at specific bonds to yield relatively stable fragments. One type of fragmentation pattern is the cleavage of a single bond in the molecular ion. The cleavage leads to a radical and a cation. The cleavage can occur at... https://www.jove.com/v/12298 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12857.jpg Mass Spectrometry of Amines In mass spectroscopy, amines undergo fragmentation to give parent ions with odd molecule weights. This observed mass spectrum follows the nitrogen rule; a molecule with an odd number of nitrogen atoms produces a molecular ion with an odd molecular weight. Amines undergo fragmentation through α cleavage, producing nitrogen-containing cations—iminium ions—and alkyl radicals. Mass spectra of aromatic and cyclic aliphatic amines exhibit strong molecular ion peaks, but acyclic aliphatic amines show... https://www.jove.com/v/12857 75 2025-12-15T23:48:04+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13048.jpg Mass Spectrometry: Amine Fragmentation Amines can be identified using mass spectroscopy based on their characteristic fragmentation patterns. The molecular ions of amines undergo fragmentation via ⍺-cleavage. The ⍺-cleavage of the carbon-carbon bonds in amines generates an alkyl radical and resonance-stabilized nitrogen-containing cation. In amines, the number of nitrogen atoms affects the mass of the molecular ion, which is described by the nitrogen rule of mass spectrometry. This rule states that a compound containing a single or... https://www.jove.com/v/13048 55 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13051.jpg Mass Spectrometry: Carboxylic Acid, Ester, and Amide Fragmentation The fragmentation patterns observed for compounds such as carboxylic acids, esters, and amides in the mass spectra include ⍺-cleavage and McLafferty rearrangement. Fragmentation by ⍺-cleavage preferentially occurs at the carbon-carbon bond at the ⍺-position next to the carboxylic group to generate a neutral radical and a cation. Long chain compounds with hydrogen at their γ-carbon undergo McLafferty rearrangement to give a radical cation and a neutral alkene. For example, the fragmentation of... https://www.jove.com/v/13051 61 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13385.jpg Peptide Identification Using Tandem Mass Spectrometry Tandem mass spectrometry, also known as MS/MS or MS2, is an analytical technique that employs two mass analyzers. Essentially it is a series of mass spectrometers that helps isolate a particular biomolecule and then helps study its chemical properties. This technique helps gather information regarding the protein from which the peptide was obtained and to study the peptides’ amino acid sequence. Identifying peptides from a complex mixture is an important component of the growing field of... https://www.jove.com/v/13385 93 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14589.jpg Mass Spectrum: Interpretation An unknown compound can be established by identifying the molecular ion peak in the mass spectrum. The molecular ion peak is often weak or absent due to the predominance of fragmentation in high-energy electron beams. In such cases, a soft-energy electron beam can be used to scan the spectrum to enhance the intensity of the molecular ion peak. Additionally, chemical ionization, field ionization, and desorption ionization spectra are used to obtain a relatively intense molecular ion peak.To... https://www.jove.com/v/14589 84 2025-12-12T20:31:50+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56652.jpg Synthesis and Mass Spectrometry Analysis of Oligo-peptoids A protocol is described for the manual synthesis of oligo-peptoids followed by sequence analysis by mass spectrometry. https://www.jove.com/v/56652 704 2018-02-21T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61799.jpg Semi-Quantitative Analysis of Peptidoglycan by Liquid Chromatography Mass Spectrometry and Bioinformatics This protocol covers a detailed analysis of peptidoglycan composition using liquid chromatography mass spectrometry coupled with advanced feature extraction and bioinformatic analysis software. https://www.jove.com/v/61799 549 2020-10-13T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62971.jpg Sample Preparation and Relative Quantitation using Reductive Methylation of Amines for Peptidomics Studies This article describes a sample preparation method based on heat-inactivation to preserve endogenous peptides avoiding degradation post-mortem, followed by relative quantitation using isotopic labeling plus LC-MS. https://www.jove.com/v/62971 480 2021-11-04T20:00:00+00:00 JoVE no https://visualize.jove.com/8111824-effects-of-deoxycorticosterone-acetate-doca-and-aldosterone-on-sar1-angiotensin-ii-binding-and-angiotensin-converting-enzyme-binding-sites-in-brain monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15020.jpg Antihypertensive Drugs: Action of β 1 Blockers β1-receptors are primarily located in the heart and kidneys. In cardiac myocytes, these receptors interact with neurotransmitters released by the sympathetic nervous system during heightened activity or danger. As a result, β1-receptors get activated, initiating a series of biochemical processes. Excessive activation of beta receptors due to chronic stress can abnormally increase heart rate and contractility, resulting in high blood pressure or hypertension. To counteract this, β1-blockers... https://www.jove.com/v/15020 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15023.jpg Antihypertensive Drugs: Angiotensin-Converting Enzyme Inhibitors Angiotensin-converting enzyme (ACE), a vital component of the renin-angiotensin-aldosterone system, is abundant in lung endothelial cells. ACE converts the inactive decapeptide, angiotensin I, into the active octapeptide, angiotensin II. This potent vasoconstrictor narrows blood vessels, increasing resistance to blood flow and elevating blood pressure. Angiotensin II also stimulates aldosterone production, encouraging kidney cells to reabsorb more sodium and water from urine, thereby increasing... https://www.jove.com/v/15023 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15024.jpg Antihypertensive Drugs: Angiotensin II Receptor Blockers In the renin-angiotensin-aldosterone system, a hormone called angiotensin II plays a crucial role. It binds to the AT1 receptors in vascular smooth muscles coupled with Gq proteins. The activation of these receptors activates an enzyme called phospholipase C, which releases two molecules: inositol trisphosphate and diacylglycerol. These molecules cause a chain reaction that leads to the phosphorylation of myosin light chains and promotes interaction between actin and myosin, leading to smooth... https://www.jove.com/v/15024 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15025.jpg Antihypertensive Drugs: Direct Renin Inhibitors The renin-angiotensin-aldosterone system (RAAS) is an intricate physiological pathway involving numerous enzymes and hormones, including renin, angiotensin-converting enzyme (ACE), angiotensin I and II, and aldosterone. Imbalances within this system increase the production of angiotensin II and aldosterone. Increased angiotensin II levels promote vasoconstriction and blood pressure elevation. Concurrently, higher aldosterone levels stimulate sodium and water reabsorption in the kidneys,... https://www.jove.com/v/15025 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15037.jpg Heart Failure Drugs: Inhibitors of Renin-Angiotensin System The activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) contributes to cardiac remodeling, and inhibiting the RAAS is a pharmacological target in heart failure management. As a result, neurohumoral modulation is a crucial treatment principle for managing heart failure. This approach involves using medications like ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), β-blockers, mineralocorticoid receptor antagonists (MRAs), and neutral... https://www.jove.com/v/15037 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16472.jpg Structure-Activity Relationships and Drug Design Drug design is a dynamic field that involves discovering and developing new medications based on specific biological targets. This process heavily relies on structure-activity relationships (SAR) and quantitative structure-activity relationships (QSAR) to guide the design and optimization of efficient drugs. SAR studies the intricate relationship between a drug's chemical structure and biological activity. It focuses on understanding how modifications to a drug's structure can influence its... https://www.jove.com/v/16472 88 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53191.jpg Subcutaneous Angiotensin II Infusion using Osmotic Pumps Induces Aortic Aneurysms in Mice Subcutaneous implantation of osmotic pumps provides a convenient approach for prolonged and consistent delivery of compounds. This approach has been used extensively to study both abdominal and thoracic aortic aneurysms in mice. https://www.jove.com/v/53191 441 2015-09-28T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53866.jpg Receptor Autoradiography Protocol for the Localized Visualization of Angiotensin II Receptors Here we present a protocol to describe the localization of angiotensin II Type 1 receptors in the rat brain by quantitative, densitometric, in vitro receptor autoradiography using an iodine-125 labeled analog of angiotensin II. https://www.jove.com/v/53866 723 2016-06-07T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58303.jpg Induction of Atherosclerotic Plaques Through Activation of Mineralocorticoid Receptors in Apolipoprotein E-deficient Mice We describe a protocol to induce atherosclerosis in the aortic root of ApoE-/- mice fed with an atherogenic diet, through a continuous release of aldosterone. Methods to characterize plaque composition are also described. https://www.jove.com/v/58303 456 2018-09-26T21:00:00+00:00 JoVE no https://visualize.jove.com/8124070-neural-mechanisms-of-behavior monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10914.jpg What is Behavior? Behaviors are actions that an organism engages in—they can be related to finding food, reproducing, defending against threats, and many other possible actions. Behaviors include activities related to the environment around the animal—such as migration—as well as social interactions within a species or population. Many behaviors involve motor output—that is, muscle movements—while others involve less visible actions, such as learning. Genetic and Environmental Influences Both genetic and... https://www.jove.com/v/10914 54 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17736.jpg Behaviorism The field of behaviorism was pioneered by figures such as Ivan Pavlov, John B. Watson, and B.F. Skinner fundamentally shifted the focus of psychology to the observable and controllable aspects of human and animal behavior. This shift marked a critical evolution in the discipline, emphasizing scientific rigor and experimental methodology. The core premise of behaviorism is its focus on observable behavior rather than internal thoughts or feelings. This approach argues that true scientific... https://www.jove.com/v/17736 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17740.jpg Introduction to Biological Bases of Psychology Biopsychology serves as a vital bridge connecting the intricate domains of biology and psychology, shedding light on how biological systems influence psychological phenomena. This field scrutinizes the biological substrates of behavior and mental processes, emphasizing the nervous system along with the roles of neurotransmitters, hormones, and genetics. It also incorporates evolutionary perspectives to explain the adaptive nature of mental functions. The nervous system, the cornerstone of... https://www.jove.com/v/17740 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17743.jpg Neuronal Communication Neurons, the fundamental units of the brain and nervous system, communicate through complex electrochemical signals that underpin all cognitive and bodily functions. This communication is primarily facilitated by a process involving the generation and propagation of an action potential along the axon of the neuron. When the internal electrical charge of a neuron surpasses a certain threshold, an action potential is triggered. This rapid change in voltage travels swiftly along the axon to the... https://www.jove.com/v/17743 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18230.jpg The Behavioral Perspective on Personality Behaviorists view personality as primarily shaped by environmental reinforcements and consequences. According to this perspective, behavior is influenced by external stimuli, and individuals adjust their actions based on rewards and punishments. Over time, learning histories — accumulated patterns of reinforcement — play a significant role in shaping personality. Behaviors that lead to positive outcomes are reinforced, while those resulting in negative outcomes are diminished. Radical... https://www.jove.com/v/18230 79 JoVE no https://cloudfront.jove.com/files/ftp_upload/19867/19867_article_thumb_19867.jpg Causes of Social Behavior III: Biological and Environmental Influences Social behavior is a complex phenomenon that arises from the interaction between biological predispositions and environmental influences. This intricate interplay shapes how individuals think, feel, and act in various social contexts. Understanding these mechanisms requires insights from psychology, neuroscience, genetics, and evolutionary theory.Environmental Influences on Social BehaviorEnvironmental factors, including temperature, odors, and visual stimuli, play a crucial role in shaping... https://www.jove.com/v/19867 88 2025-09-18T17:24:29+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51047.jpg Automated, Quantitative Cognitive/Behavioral Screening of Mice: For Genetics, Pharmacology, Animal Cognition and Undergraduate Instruction Fully automated system for measuring physiologically meaningful properties of the mechanisms mediating spatial localization, temporal localization, duration, rate and probability estimation, risk assessment, impulsivity, and the accuracy and precision of memory, in order to assess the effects of genetic and pharmacological manipulations on foundational mechanisms of cognition in mice. https://www.jove.com/v/51047 983 2014-02-27T06:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51128.jpg A Fully Automated Rodent Conditioning Protocol for Sensorimotor Integration and Cognitive Control Experiments A fully automated protocol for rodent operant conditioning is proposed. The protocol relies on precise temporal control of behavioral events to investigate the extent to which this control influences neural activity underlying sensorimotor integration and cognitive control experiments. https://www.jove.com/v/51128 583 2014-04-16T01:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52859.jpg A Method for Remotely Silencing Neural Activity in Rodents During Discrete Phases of Learning This protocol describes how to temporarily and remotely silence neuronal activity in discrete brain regions while rats are engaged in learning and memory tasks. The approach combines pharmacogenetics (Designer-Receptors-Exclusively-Activated-by-Designer-Drugs) with a behavioral paradigm (sensory preconditioning) that is designed to distinguish between different components of learning. https://www.jove.com/v/52859 562 2015-06-22T21:00:00+00:00 JoVE no https://visualize.jove.com/8134363-folded-proteins-occur-frequently-in-libraries-of-random-amino-acid-sequences monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3976.jpg Microfluidic Mixers for Studying Protein Folding In this work we explain the fabrication and use of a microfluidic mixer capable of mixing two solutions in ~8 μs. We also demonstrate the use of these mixers with spectroscopic detection using UV fluorescence and fluorescence resonance energy transfer (FRET). https://www.jove.com/v/3976 762 2012-04-10T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10679.jpg Protein Folding Overview Proteins are chains of amino acids linked together by peptide bonds. Upon synthesis, a protein folds into a three-dimensional conformation which is critical to its biological function. Interactions between its constituent amino acids guide protein folding, and hence the protein structure is primarily dependent on its amino acid sequence. Protein Structure Is Critical to Its Biological Function Proteins perform a wide range of biological functions such as catalyzing chemical... https://www.jove.com/v/10679 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10679.jpg Protein Folding Overview Proteins are chains of amino acids linked together by peptide bonds. Upon synthesis, a protein folds into a three-dimensional conformation which is critical to its biological function. Interactions between its constituent amino acids guide protein folding, and hence the protein structure is primarily dependent on its amino acid sequence. Protein Structure Is Critical to Its Biological Function Proteins perform a wide range of biological functions such as catalyzing chemical... https://www.jove.com/v/11501 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11508.jpg Amyloid Fibrils Amyloid fibrils are aggregates of misfolded proteins. Under most circumstances, misfolded proteins are either refolded by chaperone proteins or degraded by the proteasome. However, in the case of a mutation or a disease, these proteins can accumulate to form large clusters and often further assemble to form elongated fibers, called fibrils. Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining, normally used to... https://www.jove.com/v/11508 183 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11601.jpg Molecular Chaperones and Protein Folding The native conformation of a protein is formed by interactions between the side chains of its constituent amino acids. When the amino acids cannot form these interactions, the protein cannot fold by itself and needs chaperones. Notably, chaperones do not relay any additional information required for the folding of polypeptides; the native conformation of a protein is determined solely by its amino acid sequence. Chaperones catalyze protein folding without being a part of the folded protein. The... https://www.jove.com/v/11601 180 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12488.jpg Protein Folding Proteins are chains of amino acids linked together by peptide bonds. Upon synthesis, a protein folds into a three-dimensional conformation, critical to its biological function. Interactions between its constituent amino acids guide protein folding, and hence the protein structure is primarily dependent on its amino acid sequence. Protein Structure Is Critical to Its Biological Function Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing... https://www.jove.com/v/12488 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11601.jpg Molecular Chaperones and Protein Folding The native conformation of a protein is formed by interactions between the side chains of its constituent amino acids. When the amino acids cannot form these interactions, the protein cannot fold by itself and needs chaperones. Notably, chaperones do not relay any additional information required for the folding of polypeptides; the native conformation of a protein is determined solely by its amino acid sequence. Chaperones catalyze protein folding without being a part of the folded protein. The... https://www.jove.com/v/13137 180 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50476.jpg Protein WISDOM: A Workbench for In silico De novo Design of BioMolecules We developed computational de novo protein design methods capable of tackling several important areas of protein design. To disseminate these methods we present Protein WISDOM, an online tool for protein design (http://www.proteinwisdom.org). Starting from a structural template, design of monomeric proteins for increased stability and complexes for increased binding affinity can be performed. https://www.jove.com/v/50476 658 2013-07-25T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66314.jpg Computational Prediction of Amino Acid Preferences of Potentially Multispecific Peptide-Binding Domains Involved in Protein-Protein Interactions We describe a methodology based on sequence diversification to estimate the amino acid preferences of multispecific binding sites in protein-protein interactions (PPIs). In this strategy, thousands of potential peptide ligands are generated and screened in silico, thus overcoming some limitations of available experimental methods. https://www.jove.com/v/66314 410 2024-01-26T22:55:00+00:00 JoVE no https://visualize.jove.com/8136409-synaptic-integration-of-nmda-and-non-nmda-receptors-in-large-neuronal-network-models-solved-by-means-of-differential-equations monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11895.jpg Synaptic Signaling Neurons communicate at synapses, or junctions, to excite or inhibit the activity of other neurons or target cells, such as muscles. Synapses may be chemical or electrical. Most synapses are chemical, meaning an electrical impulse or action potential spurs the release of chemical messengers called neurotransmitters. The neuron sending the signal is called the presynaptic neuron, and the neuron receiving the signal is the postsynaptic neuron. The presynaptic neuron fires an action potential that... https://www.jove.com/v/11895 69 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12184.jpg The Role of Ion Channels in Neuronal Computation A postsynaptic neuron usually receives numerous impulses from several other presynaptic neurons. The axon hillock of the postsynaptic neuron integrates all these signals and determines the likelihood of firing an action potential. Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential. https://www.jove.com/v/12184 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13113.jpg Chemical Synapses Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell. Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is... https://www.jove.com/v/13113 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13113.jpg Chemical Synapses Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell. Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is... https://www.jove.com/v/14896 86 2025-06-13T16:04:18+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14899.jpg Integration of Synaptic Events Synaptic integration mainly includes the summation of graded potentials. Graded potentials, regardless of their type, cause subtle alterations in membrane voltage, resulting in either depolarization or hyperpolarization. These incremental changes, when combined or summed, can propel the neuron toward its threshold. Consider, for example, a membrane experiencing a +15 mV shift, causing it to depolarize from -70 mV to -55 mV. In this scenario, graded potentials govern the membrane's ability to... https://www.jove.com/v/14899 88 2025-06-13T16:06:36+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17743.jpg Neuronal Communication Neurons, the fundamental units of the brain and nervous system, communicate through complex electrochemical signals that underpin all cognitive and bodily functions. This communication is primarily facilitated by a process involving the generation and propagation of an action potential along the axon of the neuron. When the internal electrical charge of a neuron surpasses a certain threshold, an action potential is triggered. This rapid change in voltage travels swiftly along the axon to the... https://www.jove.com/v/17743 88 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52320.jpg Real-time Electrophysiology: Using Closed-loop Protocols to Probe Neuronal Dynamics and Beyond Closed-loop protocols are becoming increasingly widespread in modern day electrophysiology. We present a simple, versatile and inexpensive way to perform complex electrophysiological protocols in cortical pyramidal neurons in vitro, using a desktop computer and a digital acquisition board. https://www.jove.com/v/52320 488 2015-06-24T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60896.jpg 3D Modeling of Dendritic Spines with Synaptic Plasticity The protocol develops a three-dimensional (3D) model of a dendritic segment with dendritic spines for modeling synaptic plasticity. The constructed mesh can be used for computational modeling of AMPA receptor trafficking in the long-term synaptic plasticity using the software program Blender with CellBlender and MCell. https://www.jove.com/v/60896 433 2020-05-18T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67833.jpg Identification and Classification of Position-specific GABA A Receptor Subunit Missense Variants for Their Role In Hippocampal Pyramidal Neurons This study introduces a multiscale framework, spanning from DNA to protein function and neural behavior. It presents a novel approach for investigating predicted pathogenic mutations in the GABAA receptor subunit, hypothesizing that epileptogenic mutations and proximal mutations, predicted as pathogenic, may produce similar effects on the CA1 pyramidal neuron model. https://www.jove.com/v/67833 484 2025-06-06T20:15:00+00:00 JoVE no https://visualize.jove.com/8163714-computer-assisted-evaluation-of-adverse-events-using-a-bayesian-approach monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14384.jpg Pharmacovigilance Post-marketing surveillance is a critical component of pharmaceutical regulation, often uncovering unanticipated adverse drug reactions (ADRs) once a drug is widely used over an extended period. This process, termed pharmacovigilance, aims to detect, evaluate, and minimize harmful effects related to medication use. The data collection for pharmacovigilance depends on spontaneous reporting systems, where healthcare professionals or patients voluntarily report suspected ADRs. In some cases, there... https://www.jove.com/v/14384 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16484.jpg Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches Biopharmaceutical studies constitute a vital field aiming to enhance drug delivery methods and refine therapeutic approaches, drawing upon diverse interdisciplinary knowledge. In research methodologies, the choice between controlled and non-controlled studies significantly influences the study's reliability and accuracy. Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast, controlled... https://www.jove.com/v/16484 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17610.jpg Statistical Methods for Analyzing Epidemiological Data Epidemiological data primarily involves information on specific populations' occurrence, distribution, and determinants of health and diseases. This data is crucial for understanding disease patterns and impacts, aiding public health decision-making and disease prevention strategies. The analysis of epidemiological data employs various statistical methods to interpret health-related data effectively. Here are some commonly used methods: Descriptive Statistics: These provide basic summaries... https://www.jove.com/v/17610 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17618.jpg Kaplan-Meier Approach The Kaplan-Meier estimator is a non-parametric method used to estimate the survival function from time-to-event data. In medical research, it is frequently employed to measure the proportion of patients surviving for a certain period after treatment. This estimator is fundamental in analyzing time-to-event data, making it indispensable in clinical trials, epidemiological studies, and reliability engineering. By estimating survival probabilities, researchers can evaluate treatment effectiveness,... https://www.jove.com/v/17618 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18441.jpg Hazard Rate The hazard rate, also known as the hazard function or failure rate, is a statistical measure used to describe the instantaneous rate at which an event occurs, given that the event has not yet happened. From a probabilistic perspective, it represents the likelihood that a subject will experience the event in a very small time interval, conditional on surviving up to the beginning of that interval. In terms of frequency, the hazard rate can be viewed as the ratio of the number of events to the... https://www.jove.com/v/18441 71 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59649.jpg A Machine Learning Approach to Design an Efficient Selective Screening of Mild Cognitive Impairment This methodology produces decision trees that target population groups more prone to suffering from mild cognitive impairment and are useful for cost-effective selective screening of the disease. https://www.jove.com/v/59649 738 2020-01-11T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60794.jpg Implementation of a Real-Time Psychosis Risk Detection and Alerting System Based on Electronic Health Records using CogStack We demonstrate how to deploy a real-time psychosis risk calculation and alerting system based on CogStack, an information retrieval and extraction platform for electronic health records. https://www.jove.com/v/60794 451 2020-05-15T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63848.jpg A Computer-Based Platform for Aiding Clinicians in Eating Disorder Analysis and Diagnosis Diagnosing eating disorders in healthcare is challenging. Therefore, the present protocol develops an algorithm based on 949 patient responses to a questionnaire, with the diagnosis displayed on an easy-to-use web-based interface. This system facilitates the accurate diagnosis of eating disorders while excluding those believed to have an eating disorder. https://www.jove.com/v/63848 259 2022-05-10T23:00:00+00:00 JoVE no https://visualize.jove.com/8166539-surgical-outcome-of-aortic-arch-aneurysms-using-selective-cerebral-perfusion monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17981/17981_article_thumb_17981.jpg Aneurysm III: Interprofessional Care Aneurysm management involves either conservative medical therapy or surgical intervention, depending on the size and symptoms of the aneurysm. Conservative management is generally reserved for smaller, asymptomatic aneurysms, while larger or symptomatic aneurysms often necessitate surgical repair.Conservative Medical TherapyFor small, asymptomatic aneurysms, particularly abdominal aortic aneurysms (AAA) less than 5.5 centimeters in diameter, conservative medical therapy is recommended. This... https://www.jove.com/v/17981 86 2025-06-19T16:19:25+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17982/17982_article_thumb_17982.jpg Aneurysm IV: Nursing Management Vigilant monitoring for aneurysm rupture is essential for patients undergoing aortic surgery.Preoperative Nursing ManagementContinuously monitor the patient for manifestations of aneurysm rupture, such as pallor, weakness, tachycardia, hypotension, abdominal, back, groin, or periumbilical pain, changes in consciousness, and a pulsating abdominal mass. Regularly assess the patient's peripheral pulses.Instruct the patient to consume a clear liquid diet the day before surgery and administer... https://www.jove.com/v/17982 82 2025-06-19T16:19:35+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50740.jpg A New Murine Model of Endovascular Aortic Aneurysm Repair Histological and biochemical modifications after aneurysm endograft exclusion are still unclear. We describe a new model of endograft implantation on a murine aneurysm. Through thrombus analysis with and without persistant circulating blood stream interface, and new endovascular biomaterials evaluation, this model will help to better understand endovascular aneurysm exclusion pathobiology. https://www.jove.com/v/50740 531 2013-07-07T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55522.jpg Comprehensive Endovascular and Open Surgical Management of Cerebral Arteriovenous Malformations Surgery is the gold standard for accessible arteriovenious malformations (AVMs), and pre-operative embolization can simplify this procedure. We describe our approach for staged endovascular embolization and open resection of AVMs, and provide a representative clinical example highlighting the advantages of a comprehensively trained neurovascular surgeon leading a multi-disciplinary clinical team. https://www.jove.com/v/55522 898 2017-10-20T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68033.jpg Novel and Innovative Hybrid Technique for Type A Aortic Dissection The protocol describes ascending aortic replacement combined with endovascular coverage of the entire aortic arch with a fenestrated stent graft in a patient with acute type A aortic dissection in the absence of a tear in the aortic arch. https://www.jove.com/v/68033 386 2025-03-28T21:55:00+00:00 JoVE no https://visualize.jove.com/8226873-aldosterone-mediated-nak-atpase-expression-is-alpha-1-isoform-specific-in-the-renal-cortical-collecting-duct monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10893.jpg Hormonal Regulation The renin-aldosterone system is an endocrine system which guides the renal absorption of water and electrolytes, thus managing blood pressure and osmoregulation. Activation of the system begins in the kidneys with a small cluster of cells adjacent to the afferent and efferent blood vessels of the renal corpuscle. As the nephrons are filtering blood, juxtaglomerular cells monitor blood pressure. If they detect a decrease in pressure, they release the hormone renin into the bloodstream. <br... https://www.jove.com/v/10893 93 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14466.jpg Adrenergic Receptors: ɑ Subtype Adrenoceptors are classified into α and ꞵ classes based on their potencies to catecholamine agonists. α-adrenoceptors show the following order of catecholamine potency: Adrenaline ≥ Noradrenaline >> Isoprenaline α-adrenoceptors are further divided into α1 and α2-adrenoceptors. α1-Adrenoceptors: These receptors are located postsynaptically on the effector organs and cause constriction of smooth muscle mediated by activation of phospholipase C—inositol-1,4,5-trisphosphate... https://www.jove.com/v/14466 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14467.jpg Adrenergic Receptors: β Subtype β-adrenoceptors have varied sensitivities towards adrenaline, noradrenaline, and isoprenaline. The order of agonist potency is as follows: Isoprenaline > Adrenaline > Noradrenaline Neurotransmitter binding to these receptors causes activation of adenylyl cyclase resulting in increased concentrations of cAMP and modulation of calcium ion channels within the cell. They are further classified into β1, β2, and β3 subtypes. β1-adrenoceptors: β1-adrenoceptors have equal affinities for... https://www.jove.com/v/14467 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16248.jpg Renal Tubule and Collecting Duct The renal tubule is divided into three parts: the proximal convoluted tubule (PCT), the Loop of Henle (LOH), and the distal convoluted tubule (DCT). Proximal Convoluted Tubule (PCT): The PCT is the initial segment of the renal tubule, extending from the Bowman's capsule that encloses the glomerulus. Its convoluted structure and microvilli-lined cells increase the surface area for reabsorption. The PCT reabsorbs glucose, amino acids, sodium, and water from the filtrate, ensuring essential... https://www.jove.com/v/16248 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16255.jpg Reabsorption and Secretion in the DCT and Collecting Duct The early phase of the DCT manages the reabsorption of approximately 10-15% of filtered water, 5–10% of filtered sodium, and 5–10% of filtered chloride. This process is facilitated by Na+–Cl− symporters in apical membranes and sodium-potassium pumps, as well as Cl− leakage channels in basolateral membranes. The early DCT also stands out as a site where parathyroid hormone (PTH) stimulates calcium reabsorption, depending on the body's requirements. The distal part of the DCT, along with the... https://www.jove.com/v/16255 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/18456/18456_article_thumb_18456.jpg Physiology of the Genitourinary System II: Tubular Reabsorption and Secretion The kidneys maintain homeostasis through filtration, reabsorption, and secretion. Tubular reabsorption and secretion are crucial in forming urine and regulating electrolytes, water balance, and waste elimination.Tubular Reabsorption and Secretion ProcessesTubular reabsorption is the process that reclaims essential substances such as electrolytes, glucose, amino acids, and water from the glomerular filtrate back into the bloodstream. This is achieved through passive and active transport... https://www.jove.com/v/18456 82 2025-06-19T16:22:28+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50366.jpg Culturing Primary Rat Inner Medullary Collecting Duct Cells Arginine-vasopressin (AVP) controls fine-tuning of body water homeostasis through facilitating water reabsorption by renal principal cells. Here, we present a protocol for the cultivation of primary rat inner medullary collecting duct cells suitable for the elucidation of molecular mechanisms underlying AVP-mediated water reabsorption. https://www.jove.com/v/50366 371 2013-06-21T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52850.jpg Single-channel Analysis and Calcium Imaging in the Podocytes of the Freshly Isolated Glomeruli Changes in the intracellular calcium levels in the podocytes are one of the most important means to control the filtration function of glomeruli. Here we explain a high-throughput approach that allows detection of real-time calcium handling and single ion channels activity in the podocytes of the freshly isolated glomeruli. https://www.jove.com/v/52850 739 2015-06-27T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53035.jpg Implementing Patch Clamp and Live Fluorescence Microscopy to Monitor Functional Properties of Freshly Isolated PKD Epithelium Ion channels expressed in renal tubular epithelium play a significant role in the pathology of polycystic kidney disease. Here we describe experimental protocols used to perform patch-clamp analysis and intracellular calcium level measurements in cystic epithelium freshly isolated from rodent kidneys. https://www.jove.com/v/53035 526 2015-09-01T19:00:00+00:00 JoVE no https://visualize.jove.com/8233801-the-interaction-between-the-iron-responsive-element-binding-protein-and-its-cognate-rna-is-highly-dependent-upon-both-rna-sequence-and-structure monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10800.jpg Types of RNA Overview Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use. RNA... https://www.jove.com/v/10800 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11588.jpg Chromatin Structure Regulates pre-mRNA Processing In eukaryotic cells, nascent mRNA transcripts need to undergo many post-transcriptional modifications to reach the cell cytoplasm and translate into functional proteins. For a long time, transcription and pre-mRNA processing were considered two independent events that occur sequentially in the cell. However, it has now been well established that transcription and pre-mRNA processing are two simultaneous processes that are precisely regulated inside the cell. The chromatin structure, especially... https://www.jove.com/v/11588 161 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11608.jpg Cooperative Binding of Transcription Regulators Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome. Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form dimers that... https://www.jove.com/v/11608 133 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12557.jpg Types of RNA Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in regulating gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use. RNA Performs Diverse... https://www.jove.com/v/12557 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11608.jpg Cooperative Binding of Transcription Regulators Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome. Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form dimers that... https://www.jove.com/v/13144 133 JoVE no https://cloudfront.jove.com/files/ftp_upload/19535/19535_article_thumb_19535.jpg Transcriptional Regulation: Riboswitches Riboswitches are RNA elements that regulate gene expression by altering their secondary structures in response to specific effector molecules. These elements, located in the leader regions of certain mRNAs, act as transcriptional regulators by toggling between alternative conformations to control downstream gene expression. Riboswitch-mediated regulation is a precise mechanism for modulating biosynthetic pathways, as exemplified by the riboflavin biosynthesis pathway in Bacillus... https://www.jove.com/v/19535 83 2025-06-13T13:18:47+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52230.jpg Electrophoretic Mobility Shift Assay (EMSA) for the Study of RNA-Protein Interactions: The IRE/IRP Example Here we present a protocol to analyze RNA/protein interactions. The electrophoretic mobility shift assay (EMSA) is based on the differential migration of RNA/protein complexes and free RNA during native gel electrophoresis. By using a radiolabeled RNA probe, RNA/protein complexes can be visualized by autoradiography. https://www.jove.com/v/52230 764 2014-12-04T00:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59611.jpg An Assay for Quantifying Protein-RNA Binding in Bacteria In this method, we quantify the binding affinity of RNA binding proteins (RBPs) to cognate and non-cognate binding sites using a simple, live, reporter assay in bacterial cells. The assay is based on repression of a reporter gene. https://www.jove.com/v/59611 422 2019-06-12T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59635.jpg Exploring Sequence Space to Identify Binding Sites for Regulatory RNA-Binding Proteins Sequence specificity is critical for gene regulation. Regulatory proteins that recognize specific sequences are important for gene regulation. Defining functional binding sites for such proteins is a challenging biological problem. An iterative approach for identification of a binding site for an RNA-binding protein is described here and is applicable to all RNA-binding proteins. https://www.jove.com/v/59635 694 2019-08-09T21:00:00+00:00 JoVE no https://visualize.jove.com/8273875-the-australian-incident-monitoring-study-the-electrocardiograph-applications-and-limitations-an-analysis-of-2000-incident-reports monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13286.jpg Pulse rhythm Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding. Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle... https://www.jove.com/v/13286 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15273.jpg Electrocardiogram An electrocardiogram (ECG or EKG) is a critical diagnostic tool that records the electrical signals produced by the heart during each heartbeat. This recording is achieved through electrodes placed strategically on the arms, legs, and chest. The electrocardiograph amplifies these signals and produces 12 distinct tracings, offering a comprehensive understanding of the heart's electrical activity. Three major waveforms are present in a typical ECG recording: the P wave, the QRS complex, and the T... https://www.jove.com/v/15273 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17877.jpg Electrocardiogram Fundamentals Introduction An electrocardiogram (ECG) is a diagnostic tool for identifying cardiac conditions such as arrhythmias, conduction abnormalities, and myocardial ischemia. Definition An electrocardiogram (ECG) visualizes the heart's electrical activity by tracing the electrical movement associated with each heartbeat on a graph or monitor. As the heart beats, an electrical wave passes through it, correlating with the cardiac cycle events. Parts of an ECG An ECG utilizes electrodes on the skin to... https://www.jove.com/v/17877 88 JoVE no https://cloudfront.jove.com/files/ftp_upload/17887/17887_article_thumb_17887.jpg Holter Monitor: 24-Hour Monitoring Holter monitoring is a continuous electrocardiography (ECG) recording that tracks the heart's electrical activity over an extended period, generally 24 to 48 hours. This noninvasive diagnostic tool detects irregular heart rhythms that may not be captured during a standard ECG performed in a clinical setting.DeviceThe Holter monitor is a portable, small device connected to several electrodes on the patient's chest. These electrodes detect the heart's electrical signals and transmit them to the... https://www.jove.com/v/17887 83 2025-06-19T16:09:27+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17930/17930_article_thumb_17930.jpg Acute Coronary Syndrome III: Diagnostic Studies Diagnosing acute coronary syndrome or ACS begins with a thorough patient history. Notable symptoms include central, crushing chest pain radiating to the left arm, neck, jaw, or back, along with shortness of breath, sweating (diaphoresis), nausea, vomiting, dizziness, and palpitations.It is crucial to note any history of cardiac illnesses and assess risk factors, including age, gender, smoking, hypertension, diabetes, hyperlipidemia, and a sedentary lifestyle.During physical examination, vital... https://www.jove.com/v/17930 90 2025-06-19T15:08:40+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17942/17942_article_thumb_17942.jpg Dysrhythmias V: Evaluating Dysrhythmias Dysrhythmias, also known as arrhythmias, are disturbances in the heart's rhythm that range from benign to life-threatening. A thorough evaluation is crucial for appropriate management and involves a comprehensive medical history, physical examination, and various diagnostic tests.Medical HistorySymptoms: Collect detailed information on palpitations, dizziness, syncope, chest pain, and fatigue. Note their onset, frequency, and triggers.Previous Cardiac Issues: Document any history of heart... https://www.jove.com/v/17942 90 2025-06-19T16:36:46+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50124.jpg A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis Continuous 12-lead electrocardiographic (ECG) monitoring can identify transient myocardial ischemia, even when asymptomatic, among patients with suspected acute coronary syndrome (ACS). In this article we describe our method for initiating patient monitoring using a Holter device, downloading the ECG data for off-line analysis, and how to utilize the ECG software to identify transient ischemia. https://www.jove.com/v/50124 1091 2012-12-28T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60715.jpg Patient Directed Recording of a Bipolar Three-Lead Electrocardiogram using a Smartwatch with ECG Function We describe a protocol for the patient-directed registration of a three lead bipolar electrocardiogram by a smartwatch that functions identically to the Einthoven leads from standard electrocardiograms. This enables patients to record electrocardiograms on their own immediately after the onset of symptoms. https://www.jove.com/v/60715 303 2019-12-11T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62386.jpg Analyzing Long-Term Electrocardiography Recordings to Detect Arrhythmias in Mice Here we present a step-by-step protocol for a semiautomated approach to analyze murine long-term electrocardiography (ECG) data for basic ECG parameters and common arrhythmias. Data are obtained by implantable telemetry transmitters in living and awake mice and analyzed using Ponemah and its analysis modules. https://www.jove.com/v/62386 367 2021-05-23T20:00:00+00:00 JoVE no https://visualize.jove.com/8273887-the-australian-incident-monitoring-study-cardiac-arrest-an-analysis-of-2000-incident-reports monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13286.jpg Pulse rhythm Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding. Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle... https://www.jove.com/v/13286 90 JoVE no https://cloudfront.jove.com/files/ftp_upload/17930/17930_article_thumb_17930.jpg Acute Coronary Syndrome III: Diagnostic Studies Diagnosing acute coronary syndrome or ACS begins with a thorough patient history. Notable symptoms include central, crushing chest pain radiating to the left arm, neck, jaw, or back, along with shortness of breath, sweating (diaphoresis), nausea, vomiting, dizziness, and palpitations.It is crucial to note any history of cardiac illnesses and assess risk factors, including age, gender, smoking, hypertension, diabetes, hyperlipidemia, and a sedentary lifestyle.During physical examination, vital... https://www.jove.com/v/17930 90 2025-06-19T15:08:40+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17945/17945_article_thumb_17945.jpg Introduction Cardiac Emergencies Cardiac emergencies are critical situations involving the heart that require immediate medical intervention to prevent severe complications or death. These emergencies often arise from underlying heart conditions that impair the heart's ability to function correctly.Types of Cardiac EmergenciesThe most common types of cardiac emergencies include Acute Coronary Syndrome (ACS), myocardial infarction (MI), cardiac arrest, and heart failure.Acute Coronary Syndrome (ACS)Acute Coronary Syndrome (ACS)... https://www.jove.com/v/17945 90 2025-11-18T18:20:28+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17946/17946_article_thumb_17946.jpg Cardiopulmonary Resuscitation I: Adult Cardiopulmonary resuscitation, or CPR, is a life-saving emergency procedure performed when a person's heart has stopped beating or they are no longer breathing. The foundation of CPR is Basic Life Support (BLS), which focuses on the early recognition of cardiac arrest, the immediate start of high-quality chest compressions, and the timely use of an automated external defibrillator (AED).Assessing Responsiveness and Checking the Carotid PulseWhen approaching an unresponsive person, first ensure... https://www.jove.com/v/17946 81 2025-08-11T17:00:30+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17948/17948_article_thumb_17948.jpg Cardiopulmonary Resuscitation III: AED Use Introduction to AEDAn Automated External Defibrillator (AED) is a portable medical device that analyzes the heart's rhythm and, if necessary, delivers an electrical shock to help the heart re-establish an effective rhythm during sudden cardiac arrest (SCA). SCA occurs when the heart suddenly and unexpectedly stops beating, leading to a loss of blood flow to the brain and other vital organs. In such emergencies, time is of the essence, and using an AED, combined with Cardiopulmonary... https://www.jove.com/v/17948 83 2025-06-19T16:38:36+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17949/17949_article_thumb_17949.jpg Cardiopulmonary Resuscitation IV: Pharmacological Management Pharmacologic intervention is crucial in treating cardiac arrest patients during ACLS or Advanced Cardiovascular Life Support. The ACLS algorithms guide the administration of specific drugs based on the patient's cardiac arrest rhythm, which includes pulseless ventricular tachycardia (VT), ventricular fibrillation (VF), asystole, and pulseless electrical activity (PEA).EpinephrineIndication: Epinephrine is the first-line drug for all cardiac arrest rhythms.Mechanism of Action: Epinephrine... https://www.jove.com/v/17949 85 2025-07-31T20:24:37+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50124.jpg A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis Continuous 12-lead electrocardiographic (ECG) monitoring can identify transient myocardial ischemia, even when asymptomatic, among patients with suspected acute coronary syndrome (ACS). In this article we describe our method for initiating patient monitoring using a Holter device, downloading the ECG data for off-line analysis, and how to utilize the ECG software to identify transient ischemia. https://www.jove.com/v/50124 1091 2012-12-28T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63957.jpg Technical Refinement of a Bilateral Renal Ischemia-Reperfusion Mouse Model for Acute Kidney Injury Research This study established a protocol focusing on the technical refinement of a mouse model of bilateral renal ischemia-reperfusion for acute kidney injury research. https://www.jove.com/v/63957 193 2023-11-03T21:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65340.jpg Mouse Cardiac Arrest Model for Brain Imaging and Brain Physiology Monitoring During Ischemia and Resuscitation This protocol demonstrates a unique mouse model of asphyxia cardiac arrest that does not require chest compression for resuscitation. This model is useful for monitoring and imaging the dynamics of brain physiology during cardiac arrest and resuscitation. https://www.jove.com/v/65340 438 2023-04-14T22:00:00+00:00 JoVE no https://visualize.jove.com/8273899-the-australian-incident-monitoring-study-system-failure-an-analysis-of-2000-incident-reports monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13517.jpg SBAR II: Application of SBAR SBAR is an effective communication tool used by healthcare professionals to communicate patient information accurately. SBAR stands for Situation, Background, Assessment, and Recommendation. For a better understanding, an example is given below. SBAR Report from a Nurse to a Health Care Provider S: "Hello, Dr. Smith. This is Jane, RN, from the Med Surg unit. I am calling to tell you about Ms. White in Room 210, who is experiencing increased pain and redness at her incision site. Her recent... https://www.jove.com/v/13517 74 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14121.jpg Types of Reports II: Incident or Occurrence Report An Incident or Occurrence Report in a healthcare setting is a crucial document used to record any unexpected occurrence that may or may not have affected a patient, employee, or visitor. Such reports are critical to improving patient safety and include all details leading up to and including the event. Purposes: In the healthcare industry, reports play a crucial role in documenting incidents within an agency. The primary objective of these reports is to ensure patient safety, uphold the... https://www.jove.com/v/14121 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14122.jpg Types of Reports III: Telephone and Verbal Reports Telephone and Verbal Reports in healthcare settings are two communication methods for conveying therapeutic instructions from healthcare providers to nurses or other healthcare staff. Here's an overview of each type: Telephone Orders Usage: Telephone orders are used when a healthcare provider needs to communicate therapeutic instructions to a nurse or other staff over the phone. It often happens when the provider cannot be physically present. Confirmation and Documentation: Oral confirmation... https://www.jove.com/v/14122 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14384.jpg Pharmacovigilance Post-marketing surveillance is a critical component of pharmaceutical regulation, often uncovering unanticipated adverse drug reactions (ADRs) once a drug is widely used over an extended period. This process, termed pharmacovigilance, aims to detect, evaluate, and minimize harmful effects related to medication use. The data collection for pharmacovigilance depends on spontaneous reporting systems, where healthcare professionals or patients voluntarily report suspected ADRs. In some cases, there... https://www.jove.com/v/14384 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14507.jpg Systematic Error: Methodological and Sampling Errors In the case of systematic errors, the sources can be identified, and the errors can be subsequently minimized by addressing these sources. According to the source, systematic errors can be divided into sampling, instrumental, methodological, and personal errors. Sampling errors originate from improper sampling methods or the wrong sample population. These errors can be minimized by refining the sampling strategy. Defective instruments or faulty calibrations are the sources of instrumental... https://www.jove.com/v/14507 75 JoVE no https://cloudfront.jove.com/files/ftp_upload/17930/17930_article_thumb_17930.jpg Acute Coronary Syndrome III: Diagnostic Studies Diagnosing acute coronary syndrome or ACS begins with a thorough patient history. Notable symptoms include central, crushing chest pain radiating to the left arm, neck, jaw, or back, along with shortness of breath, sweating (diaphoresis), nausea, vomiting, dizziness, and palpitations.It is crucial to note any history of cardiac illnesses and assess risk factors, including age, gender, smoking, hypertension, diabetes, hyperlipidemia, and a sedentary lifestyle.During physical examination, vital... https://www.jove.com/v/17930 90 2025-06-19T15:08:40+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60361.jpg Design and Analysis for Fall Detection System Simplification We present a methodology based on multimodal sensors to configure a simple, comfortable and fast fall detection and human activity recognition system. The goal is to build a system for accurate fall detection that can be easily implemented and adopted. https://www.jove.com/v/60361 485 2020-04-06T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62933.jpg Optical Coherence Tomography Based Biomechanical Fluid-Structure Interaction Analysis of Coronary Atherosclerosis Progression There is a need to determine which atherosclerotic lesions will progress in the coronary vasculature to guide intervention before myocardial infarction occurs. This article outlines the biomechanical modeling of arteries from Optical Coherence Tomography using fluid-structure interaction techniques in a commercial finite element solver to help predict this progression. https://www.jove.com/v/62933 787 2022-01-15T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66886.jpg Eye Tracking During A Complex Aviation Task For Insights Into Information Processing Eye tracking is a non-invasive method to probe information processing. This article describes how eye tracking can be used to study gaze behavior during a flight simulation emergency task in low-time pilots (i.e., <350 flight hours). https://www.jove.com/v/66886 468 2025-04-04T19:00:00+00:00 JoVE no https://visualize.jove.com/8287744-internal-anal-sphincter-activity-after-restorative-proctocolectomy-for-ulcerative-colitis-a-study-using-continuous-ambulatory-manometry monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4086.jpg Functional Assessment of Intestinal Motility and Gut Wall Inflammation in Rodents: Analyses in a Standardized Model of Intestinal Manipulation Postoperative ileus (POI) is a complication of abdominal surgery leading to increased morbidity and a prolonged hospital stay. Because prophylactic or therapeutic strategies are lacking intensified research is necessary. Therefore we established a standardized and feasible mouse model to investigate the pathophysiology of POI and to study potential therapeutic options. https://www.jove.com/v/4086 584 2012-09-11T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15389.jpg Drugs for Treatment of Constipation-Predominant IBS Pharmacological therapies for IBS-C are designed to alleviate abdominal discomfort and enhance bowel function. In patients with IBS-C, fiber supplements may help soften stools and decrease straining, but may also lead to increased gas production and bloating. Osmotic laxatives like milk of magnesia are frequently used to soften stools and increase stool frequency in IBS-C patients. In addition, two drugs approved for use in severe IBS-C adult cases are linaclotide (Linzess) and lubiprostone... https://www.jove.com/v/15389 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16413.jpg Assessment of the Rectum and Anus Evaluating the rectum and anus plays a crucial role in conducting a thorough physical examination of the gastrointestinal system. Although it may be uncomfortable and often embarrassing for the patient, it holds immense diagnostic value, particularly in detecting gastrointestinal diseases and abnormalities. This guide will explain how to perform this assessment using inspection and palpation methods. Rectal Inspection Begin by inspecting the perianal and anal areas for color, texture, rashes,... https://www.jove.com/v/16413 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16433.jpg Irritable Bowel Syndrome III: Medical and Nursing Management Managing Irritable Bowel Syndrome (IBS) involves a multifaceted approach, including lifestyle modifications, dietary changes, and medication. Lifestyle adjustments often incorporate stress reduction techniques like yoga, meditation, and regular physical activity to alleviate symptoms like bloating and constipation. A critical component of dietary management is the introduction of soluble fiber, which can be found in foods like oats, barley, apples, and carrots. Restricting and then gradually... https://www.jove.com/v/16433 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16444.jpg Inflammatory Bowel Disease V: Surgical Management Surgical interventions for inflammatory bowel disease (IBD), which includes ulcerative colitis and Crohn's disease, are essential in managing symptoms and addressing complications. The selection of surgical procedures is contingent upon the specific conditions and complications that stem from these illnesses. Here are some common surgical interventions for IBD: Strictureplasty Proctocolectomy or total colectomy with ileostomy Restorative proctocolectomy with Ileal pouch-anal anastomosis<br... https://www.jove.com/v/16444 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16450.jpg Imaging Studies III: Gastrointestinal Motility Studies and Virtual Colonoscopy This lesson explores three gastrointestinal imaging techniques: radionuclide testing, colonic transit studies, and virtual colonoscopy. Radionuclide Testing Radionuclide testing is a sophisticated medical technique for assessing gastrointestinal motility. It focuses on gastric emptying and colonic transit time. Radioactive markers track the movement of food through the digestive system, providing insights into gastrointestinal disorders. In gastric emptying studies, a meal's liquid and solid... https://www.jove.com/v/16450 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16454.jpg Endoscopic Procedures IV: Sigmoidoscopy and Laproscopy Sigmoidoscopy and laparoscopy are distinct medical procedures that enable physicians to internally inspect different parts of the GI tract. Although they serve different purposes, each is essential for diagnosing and, in some cases, treating various medical conditions. Sigmoidoscopy Sigmoidoscopy is a diagnostic procedure that uses a flexible sigmoidoscope equipped with a light source and camera to examine the rectum and sigmoid colon. The procedure involves inserting the tube through the anus... https://www.jove.com/v/16454 86 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52310.jpg In vitro Functional Characterization of Mouse Colorectal Afferent Endings This video demonstrates a protocol for conducting single-fiber electrophysiological recordings on an in vitro mouse colorectum-nerve preparation. https://www.jove.com/v/52310 849 2015-01-21T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53828.jpg Video Imaging and Spatiotemporal Maps to Analyze Gastrointestinal Motility in Mice This article describes a video imaging technique and high-resolution spatiotemporal mapping to identify changes in the neural regulation of colonic motility in adult mice. Subtle effects on gastrointestinal (GI) function can be detected using this approach in isolated tissue preparations to advance our understanding of GI disease. https://www.jove.com/v/53828 461 2016-02-03T23:00:00+00:00 JoVE no https://visualize.jove.com/8343434-application-of-multivariate-fuzzy-set-and-neural-network-analysis-in-quantitative-cytological-examinations monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13379.jpg Flow Cytometry The development of flow cytometry techniques began in 1934 with initial attempts by Andrew Moldavan, a bacteriologist who counted the cells in a flowing capillary system. Moldavan pumped cells through a capillary tube focused under a microscope for visualization. The invention of photometry allowed the measurement of differentially-stained cells, and Louis Kamentsky developed the first multiparameter flow cytometer in 1965 to identify and count the cancer cells in cervical tissue specimens. In... https://www.jove.com/v/13379 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52241.jpg Flow Cytometry Protocols for Surface and Intracellular Antigen Analyses of Neural Cell Types We provide a detailed description of a protocol for flow cytometric analysis of surface antigens and/or intracellular antigens in neural cell types. Critical aspects of experimental planning, step-by-step methodological procedures, and fundamental principles of flow cytometry are explained in order to enable neurobiologists to exploit this powerful technology. https://www.jove.com/v/52241 785 2014-12-18T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64549.jpg Automation of the Micronucleus Assay Using Imaging Flow Cytometry and Artificial Intelligence The micronucleus (MN) assay is a well-established test for quantifying DNA damage. However, scoring the assay using conventional techniques such as manual microscopy or feature-based image analysis is laborious and challenging. This paper describes the methodology to develop an artificial intelligence model to score the MN assay using imaging flow cytometry data. https://www.jove.com/v/64549 551 2023-01-27T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66889.jpg Generating and Analyzing High-Parameter Histology Images with Histoflow Cytometry Described here is a method that can be used to image five or more fluorescent parameters by immunofluorescent microscopy. An analysis pipeline for extracting single cells from these images and conducting single-cell analysis through flow cytometry-like gating strategies is outlined, which can identify cell subsets in tissue sections. https://www.jove.com/v/66889 322 2024-06-21T22:00:00+00:00 JoVE no https://visualize.jove.com/8357528-effects-of-repeated-amphetamine-injections-on-lateral-hypothalamic-brain-stimulation-reward-and-subsequent-locomotion monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/53107.jpg Assessment of Cocaine-induced Behavioral Sensitization and Conditioned Place Preference in Mice This protocol is intended to enable researchers to conduct experiments designed to test these aspects of addiction using the conditioned place preference and locomotor behavioral sensitization assays. https://www.jove.com/v/53107 628 2016-02-18T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53266.jpg A General Method for Evaluating Deep Brain Stimulation Effects on Intravenous Methamphetamine Self-Administration This article describes the delivery of intracranial electrical stimulation that is temporally and spatially separate from the drug-use environment for the treatment of IV methamphetamine dependence. https://www.jove.com/v/53266 556 2016-01-22T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63185.jpg Using Optogenetics to Reverse Neuroplasticity and Inhibit Cocaine Seeking in Rats The methods described here outline a procedure used to optogenetically reverse cocaine-induced plasticity in a behaviorally-relevant circuit in rats. Sustained low-frequency optical stimulation of thalamo-amygdala synapses induces long-term depression (LTD). In vivo optogenetically-induced LTD in cocaine-experienced rats resulted in the subsequent attenuation of cue-motivated drug seeking. https://www.jove.com/v/63185 583 2021-10-05T20:00:00+00:00 JoVE no https://visualize.jove.com/8388675-pathophysiology-of-massive-infantile-spasms-perspective-on-the-putative-role-of-the-brain-adrenal-axis monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10879.jpg Hypothalamic-Pituitary Axis The response to stress—be it physical or psychological, acute or chronic—involves activation of the Hypothalamic-Pituitary-Adrenal (HPA) axis. The HPA axis is part of the neuroendocrine system because it involves both neuronal and hormonal communication. Its function is to regulate homeostatic systems—metabolic, cardiovascular, and immune—providing the necessary means to respond to a stressor. What Happens During Stress In response to stress, the neurons in the hypothalamus release... https://www.jove.com/v/10879 97 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14988.jpg Adrenal Gland Disorders Adrenal gland disorders manifest when the production of adrenal hormones deviates from the norm, resulting in either excessive or insufficient concentrations. Adrenal insufficiency, characterized by insufficient cortisol and aldosterone production, leads to conditions like Addison's disease. This disorder, affecting the adrenal cortex, exhibits symptoms such as skin bronzing, dehydration, low blood pressure, fatigue, and weight loss. Congenital adrenal hyperplasia, a genetic ailment causing... https://www.jove.com/v/14988 87 JoVE no https://cloudfront.jove.com/files/ftp_upload/40801/40801_article_thumb_40801.jpg Gut-Brain Axis The gut–brain axis is a bidirectional communication system that connects the gastrointestinal tract and the brain. This interaction is mediated through multiple pathways, including the vagus nerve, hormonal signals, immune responses, and chemical messengers produced by gut microbes.Microbial Contributions to Brain FunctionGut microbiota contributes significantly to brain function by producing neuroactive compounds. These include neuroactive compounds that influence neurotransmitters such as... https://www.jove.com/v/40801 82 2026-03-12T20:36:11+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40895/40895_article_thumb_40895.jpg Cushing Syndrome I: Introduction Cushing syndrome refers to the collection of clinical manifestations that arise when tissues are exposed to excessive amounts of cortisol or cortisol-like medications over an extended period. Cortisol, a glucocorticoid produced by the adrenal cortex, regulates metabolism, immune responses, and the body’s adaptation to stress. When its concentration remains chronically elevated, these physiological pathways become dysregulated, resulting in the characteristic features of the syndrome.Exogenous... https://www.jove.com/v/40895 86 2026-04-13T21:37:50+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40896/40896_article_thumb_40896.jpg Cushing Syndrome II: Pathophysiology Cortisol production is normally governed by the hypothalamic–pituitary–adrenal (HPA) axis, which maintains hormonal balance through tightly regulated feedback mechanisms. Disruption of this regulatory system is central to the development of Cushing syndrome, whether the excess cortisol originates from external medications or internal pathology. Persistent cortisol elevation alters metabolism, immune function, and endocrine signaling, producing the characteristic clinical features of the... https://www.jove.com/v/40896 79 2026-04-13T21:37:37+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40938/40938_article_thumb_40938.jpg Cerebral Edema ll: Pathophysiology Vasogenic edema is a major form of cerebral edema characterized by abnormal accumulation of fluid in the brain’s extracellular space due to disruption of the blood–brain barrier (BBB). The BBB is a specialized structure composed of endothelial cells connected by tight junctions, supported by astrocytic endfeet and a basement membrane. Under normal conditions, it tightly regulates the movement of ions, proteins, and solutes between the bloodstream and brain parenchyma. When this barrier loses... https://www.jove.com/v/40938 82 2026-04-13T23:56:04+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53196.jpg Modeling Encephalopathy of Prematurity Using Prenatal Hypoxia-ischemia with Intra-amniotic Lipopolysaccharide in Rats Encephalopathy of prematurity encompasses the central nervous system abnormalities associated with injury from preterm birth. This report describes a clinically relevant rat model of in utero transient systemic hypoxia-ischemia and intra-amniotic lipopolysaccharide administration (LPS) that mimics chorioamnionitis, and the related impact of infectious stimuli and placental underperfusion on CNS development. https://www.jove.com/v/53196 456 2015-11-20T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57391.jpg Adaptation of Microelectrode Array Technology for the Study of Anesthesia-induced Neurotoxicity in the Intact Piglet Brain This study explores the novel use of enzyme-based microelectrode array (MEA) technology to monitor in vivo neurotransmitter activity in piglets. The hypothesis was that glutamate dysregulation contributes to the mechanism of anesthetic neurotoxicity. Here, we present a protocol to adapt MEA technology to study the mechanism of anesthesia-induced neurotoxicity. https://www.jove.com/v/57391 503 2018-05-12T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68435.jpg Hypoxia Alters miRNAs Levels Involved in Non-Mendelian Inheritance of Autism Spectrum Disorder in Mice Here, we present a protocol to induce hypoxia in neonatal mice by delivering them in controlled environments with varying oxygen concentrations. Mouse models subjected to oxygen variations at birth have durably varied the expression of miRNAs involved in the induction of behavioral phenotypic changes such as autism. https://www.jove.com/v/68435 553 2025-07-11T20:20:00+00:00 JoVE no https://visualize.jove.com/8390991-molecular-requirements-for-the-cell-surface-expression-of-multisubunit-ion-transporting-atpases-identification-of-protein-domains-that-participate-in-nak-atpase-and-hk-atpase-subunit-assembly monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11877.jpg ATP Driven Pumps I: An Overview ATP-driven pumps, also known as transport ATPases, are integral membrane proteins. They have binding sites for ATP located on the membrane's cytosolic side and the ion-conducting domain in the transmembrane region. These pumps use the free energy released from ATP hydrolysis to move the solutes across cell membranes against an electrochemical gradient. There are four main types of ATP-driven pumps - P-type, V-type, F-type, and ABC transporter. All these pumps are of varying complexities and are... https://www.jove.com/v/11877 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11901.jpg ATP Synthase: Mechanism In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP... https://www.jove.com/v/11901 108 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11904.jpg ATP Synthase: Structure ATP synthase or ATPase is among the most conserved proteins found in bacteria, mammals, and plants. This enzyme can catalyze a forward reaction in response to the electrochemical gradient, producing ATP from ADP and inorganic phosphate. ATP synthase can also work in a reverse direction by hydrolyzing ATP and generating an electrochemical gradient. Different forms of ATP synthases have evolved special features to meet the specific demands of the cell. Based on their specific feature, ATP... https://www.jove.com/v/11904 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11905.jpg The ADP/ATP Carrier Protein ADP/ATP carrier or AAC protein is the most abundant carrier protein in the inner mitochondrial membrane. It transports large quantities of ADP and ATP, equivalent to the average human body weight, every day. Among other transporters, ACC protein is one of the best-studied members of the mitochondrial carrier protein family. The ADP/ATP carrier protein comprises two transmembrane helices connected to a loop and a single alpha-helix on the matrix side. It switches between two conformational... https://www.jove.com/v/11905 102 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12217.jpg ATP Driven Pumps II: P-type Pumps The P-type pumps are a large family of integral membrane transporter ATPases. They are divided into five major types based on substrate specificity, from I to V. A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly... https://www.jove.com/v/12217 94 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12218.jpg ATP Driven Pumps III: V-type Pumps V-type pumps are ATP-driven pumps found in the vacuolar membranes of plants, yeast, endosomal and lysosomal membranes of animal cells, plasma membranes of a few specialized eukaryotic cells, and some prokaryotes. They are also known as the V1Vo-ATPase, that couple ATP hydrolysis to transport protons against a concentration gradient. The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits... https://www.jove.com/v/12218 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50201.jpg Measuring Cation Transport by Na,K- and H,K-ATPase in Xenopus Oocytes by Atomic Absorption Spectrophotometry: An Alternative to Radioisotope Assays We describe a method to quantify the activity of K+-countertransporting P-type ATPases by heterologous expression of the enzymes in Xenopus oocytes and measuring Rb+ or Li+ uptake into individual cells by atomic absorption spectrophotometry. The method is a sensitive and safe alternative to radioisotope flux experiments facilitating complex kinetic studies. https://www.jove.com/v/50201 768 2013-02-19T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62770.jpg Chemical Modification of the Tryptophan Residue in a Recombinant Ca 2+ -ATPase N-domain for Studying Tryptophan-ANS FRET ANS binds to the Ca2+-ATPase recombinant N-domain. Fluorescence spectra display a FRET-like pattern upon excitation at a wavelength of 295 nm. NBS-mediated chemical modification of Trp quenches the fluorescence of the N-domain, which leads to the absence of energy transfer (FRET) between the Trp residue and ANS. https://www.jove.com/v/62770 727 2021-10-09T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67748.jpg Purification of the Sarco-Endoplasmic Reticulum Ca 2+ -ATPase from Rabbit Muscle This protocol describes an improved SERCA purification method, which includes the disaccharide trehalose in the final centrifugation step. This carbohydrate stabilizes proteins under harsh conditions. The purified SERCA was catalytically active and displayed high purity, making it suitable for structural and functional studies. https://www.jove.com/v/67748 517 2025-03-21T21:00:00+00:00 JoVE no https://visualize.jove.com/8395379-carbachol-induced-increase-of-nah-antiport-and-recruitment-of-nak-atpase-in-rabbit-lacrimal-acini monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14447.jpg Direct-Acting Cholinergic Agonists: Pharmacokinetics Direct-acting cholinergic agonists, such as synthetic choline esters and naturally occurring alkaloids, exert their effects by enhancing the actions of acetylcholine and stimulating the parasympathetic nervous system. Synthetic choline esters share structural similarities with acetylcholine. For example, they have a positively charged quaternary ammonium or onium group, contributing to their hydrophilic characteristics. As a result, they are poorly absorbed in the body through oral... https://www.jove.com/v/14447 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14467.jpg Adrenergic Receptors: β Subtype β-adrenoceptors have varied sensitivities towards adrenaline, noradrenaline, and isoprenaline. The order of agonist potency is as follows: Isoprenaline > Adrenaline > Noradrenaline Neurotransmitter binding to these receptors causes activation of adenylyl cyclase resulting in increased concentrations of cAMP and modulation of calcium ion channels within the cell. They are further classified into β1, β2, and β3 subtypes. β1-adrenoceptors: β1-adrenoceptors have equal affinities for... https://www.jove.com/v/14467 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16254.jpg Reabsorption and Secretion in the Loop of Henle The thick ascending limb of the nephron loop has Na+–K+–2Cl− symporters in the apical membranes of its cells. These symporters simultaneously reclaim one sodium ion, one potassium ion, and two chloride ions from the tubular fluid. Sodium ions are actively transported into the interstitial fluid at the base and sides of the cell, diffusing into the vasa recta. Chloride ions move through leakage channels in the basolateral membrane into the interstitial fluid and then into the vasa recta.<br... https://www.jove.com/v/16254 77 JoVE no https://cloudfront.jove.com/files/ftp_upload/18456/18456_article_thumb_18456.jpg Physiology of the Genitourinary System II: Tubular Reabsorption and Secretion The kidneys maintain homeostasis through filtration, reabsorption, and secretion. Tubular reabsorption and secretion are crucial in forming urine and regulating electrolytes, water balance, and waste elimination.Tubular Reabsorption and Secretion ProcessesTubular reabsorption is the process that reclaims essential substances such as electrolytes, glucose, amino acids, and water from the glomerular filtrate back into the bloodstream. This is achieved through passive and active transport... https://www.jove.com/v/18456 82 2025-06-19T16:22:28+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59631.jpg A Rabbit Model of Aqueous-Deficient Dry Eye Disease Induced by Concanavalin A Injection into the Lacrimal Glands: Application to Drug Efficacy Studies This article describes the development of a method to induce acute or chronic dry eye disease in rabbits by injecting concanavalin A to all portions of the orbital lacrimal gland system. This method, superior to those already reported, generates a reproducible, stable model of dry eye suitable for the study of pharmacological agents. https://www.jove.com/v/59631 484 2020-01-24T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60126.jpg Establishment of a Severe Dry Eye Model Using Complete Dacryoadenectomy in Rabbits A novel approach is presented to induce chronic dry eye disease in rabbits by surgically removing all orbital lacrimal glands. This method, distinct from those previously reported, produces a stable, reproducible model of aqueous deficient dry eye well suited to study tear physiology and pathophysiology and ocular therapeutics. https://www.jove.com/v/60126 463 2020-01-08T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66036.jpg A Rat Dry Eye Model with Lacrimal Gland Dysfunction Induced by Scopolamine Here, we establish a rat model of lacrimal gland dysfunction to provide a basis for the study of aqueous-deficient dry eye. https://www.jove.com/v/66036 246 2024-02-09T21:45:00+00:00 JoVE no https://visualize.jove.com/8428981-interactions-of-a-hybrid-insulininsulin-like-growth-factor-i-analog-with-chimeric-insulintype-i-insulin-like-growth-factor-receptors monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17293.jpg Insulin: The Receptor and Signaling Pathways Insulin action is mediated through a receptor tyrosine kinase, akin to the IGF-1 receptor. The number of receptors per cell varies significantly, from 40 on erythrocytes to 300,000 on adipocytes and hepatocytes. The insulin receptor consists of linked α/β subunit dimers, forming a heterotetramer glycoprotein with two extracellular α subunits and two β subunits spanning the membrane. The α subunits inhibit the inherent tyrosine kinase activity of the β subunits, but this inhibition is released... https://www.jove.com/v/17293 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17297.jpg Insulin: Biosynthesis, Chemistry, and Preparation The endoplasmic reticulum (ER) of pancreatic β-cells synthesizes preproinsulin, which consists of a signal peptide, A and B chains, and a C-peptide. Preproinsulin is then cleaved and folded into proinsulin, which translocates to the Golgi apparatus for sorting and packaging into secretory granules. In these granules, enzymatic clipping generates insulin and C-peptide. Damage or functional impairment of β-cells inhibits insulin production, leading to diabetes. Diabetes treatment primarily uses... https://www.jove.com/v/17297 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17298.jpg Insulin Formulations: Types and Delivery Insulin preparations are categorized by their duration of action into short-acting and long-acting types. Two strategies are used to modify insulin's absorption and pharmacokinetic profile: slowing the absorption post-subcutaneous injection, or altering human insulin's amino acid sequence or protein structure. These changes retain the insulin's ability to bind to the insulin receptor, but alter its behavior in solution or after injection. Short-acting insulins are divided into rapid-acting... https://www.jove.com/v/17298 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17299.jpg Insulin: Dosing Regimen and Adverse Effects Insulin-replacement therapy usually includes both long-acting insulin (basal) and short-acting insulin (to cater to postprandial needs). In a diverse group of type 1 diabetes patients, the average daily insulin dose is typically 0.5-0.7 units/kg body weight. However, obese patients and pubertal adolescents may need more due to insulin resistance. The basal dose constitutes about 40%-50% of the total daily dose, with the rest as premeal insulin. The mealtime insulin dose should mirror... https://www.jove.com/v/17299 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17302.jpg Oral Hypoglycemic Agents: Glinides Repaglinide (Prandin) and Nateglinide (Starlix), known as glinides, are oral insulin secretagogues that stimulate insulin release from pancreatic β cells by closing the ATP-sensitive potassium channels (KATP channel). Repaglinide controls insulin release from pancreatic β cells by managing potassium efflux. It shares two binding sites with sulfonylureas and also has a unique site, indicating overlapping mechanisms of action. With a rapid onset and a 4-7 hour duration, it effectively manages... https://www.jove.com/v/17302 66 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17304.jpg Glucagon-like Receptor Agonists Incretins include glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), which stimulate insulin secretion post-meals. In type 2 diabetes, GIP's efficacy is reduced, making GLP-1 a viable drug target. GIP originates from preproGIP. GLP-1, when administered in high doses intravenously, triggers insulin secretion, inhibits glucagon release, slows gastric emptying, reduces food intake, and restores normal insulin secretion. However, its rapid inactivation by the... https://www.jove.com/v/17304 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50365.jpg Coculture Analysis of Extracellular Protein Interactions Affecting Insulin Secretion by Pancreatic Beta Cells Transcellular protein interactions are important determinants of pancreatic beta-cell function. Detailed here is a method—adapted from a coculture model of synaptogenesis—for investigating how specific transmembrane proteins influence insulin secretion. Transfected HEK293 cells express proteins of interest; beta cells do not need to be transfected or otherwise directly perturbed. https://www.jove.com/v/50365 351 2013-06-15T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57237.jpg An In Ovo Model for Testing Insulin-mimetic Compounds In this study, we describe an in-ovo system as a promising tool to test insulin-mimetic compounds in a living organism. The main advantages include adequate throughput rates and acceptable costs, which enable the identification of phytochemicals with insulin-mimetic properties. https://www.jove.com/v/57237 369 2018-04-23T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57531.jpg Homogeneous Time-resolved Förster Resonance Energy Transfer-based Assay for Detection of Insulin Secretion Here, we present homogeneous time resolved FRET (HTRF) as an efficient method for rapid detection of insulin secreted from cells. https://www.jove.com/v/57531 450 2018-05-10T21:00:00+00:00 JoVE no https://visualize.jove.com/8432707-transferable-streptomyces-dna-amplification-and-coamplification-of-foreign-dna-sequences monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3698.jpg Site-specific Bacterial Chromosome Engineering: ΦC31 Integrase Mediated Cassette Exchange (IMCE) A quick and efficient method to integrate foreign DNA of interest into pre-made acceptor strains, termed landing pad strains, is described. The method allows site-specific integration of a DNA cassette into the engineered landing pad locus of a given strain, through conjugation and expression of the ΦC31 integrase. https://www.jove.com/v/3698 501 2012-03-16T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/10982/10982_article_thumb_10982.jpg Bacterial Transformation In 1928, bacteriologist Frederick Griffith worked on a vaccine for pneumonia, which is caused by Streptococcus pneumoniae bacteria. Griffith studied two pneumonia strains in mice: one pathogenic and one non-pathogenic. Only the pathogenic strain killed host mice.Griffith made an unexpected discovery when he killed the pathogenic strain and mixed its remains with the live, non-pathogenic strain. Not only did the mixture kill host mice, but it also contained living pathogenic bacteria that... https://www.jove.com/v/10982 93 2026-06-01T13:28:13+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11575.jpg Conservative Site-specific Recombination and Phase Variation Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines. The recognition sites for Cre recombinase called LoxP... https://www.jove.com/v/11575 173 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54854.jpg Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation Here, we present a protocol to knockout a gene of interest involved in plasmid conjugation and subsequently analyze the impact of its absence using mating assays. The function of the gene is further explored to a specific region of its sequence using deletion or point mutations. https://www.jove.com/v/54854 641 2017-01-04T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63012.jpg A High-Yield Streptomyces Transcription-Translation Toolkit for Synthetic Biology and Natural Product Applications This protocol details an enhanced method for synthesizing high yields of recombinant proteins from a Streptomyces venezuelae cell-free transcription-translation (TX-TL) system. https://www.jove.com/v/63012 479 2021-09-10T22:00:00+00:00 JoVE no https://visualize.jove.com/8450491-a-method-for-radioligand-binding-assays-using-a-robotic-workstation monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/53575.jpg An ELISA Based Binding and Competition Method to Rapidly Determine Ligand-receptor Interactions The presented protocols describe two enzyme-linked immunosorbent assay (ELISA) based techniques for the rapid investigation of ligand-receptor interactions: The first assay allows the determination of dissociation constant between ligand and receptor. The second assay enables a rapid screening of blocking peptides for ligand-receptor interactions. https://www.jove.com/v/53575 520 2016-03-14T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58879.jpg Autoradiography as a Simple and Powerful Method for Visualization and Characterization of Pharmacological Targets The method of autoradiography is routinely used to study binding of radioligands to tissue sections for determination of qualitative or quantitative pharmacology. https://www.jove.com/v/58879 616 2019-03-12T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66507.jpg Characterizing Modulators of Protease-Activated Receptors with a Calcium Mobilization Assay Using a Plate Reader An improved protocol for a calcium mobilization assay with endothelial cells, used to identify ligands of protease-activated receptors (PARs), has been developed. The new protocol reduces total assay time by 90-120 min and yields reproducible concentration-response curves. https://www.jove.com/v/66507 433 2024-05-24T20:10:00+00:00 JoVE no https://visualize.jove.com/8457856-the-central-nucleus-of-the-rat-amygdala-in-vitro-intracellular-recordings monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18185.jpg Role of Amygdala in Memory The amygdala is a small, almond-shaped structure responsible for processing and storing memories, particularly those linked to emotions like fear and stress. It plays an essential role in the brain's response to emotionally significant events and often enhances memory formation by triggering stress hormone release. The amygdala is vital for encoding and retrieving memories associated with fear or stress, a process that is adaptive by helping organisms avoid dangerous situations. One of the... https://www.jove.com/v/18185 76 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53207.jpg Caspase-3 Activity in the Rat Amygdala Measured by Spectrofluorometry After Myocardial Infarction Myocardial infarction (MI) is not only followed by impaired cardiac function but also by apoptosis in the amygdala, a brain region involved in the behavioral consequences of MI. This protocol describes how to induce MI, collect amygdala tissue and measure caspase-3 activity, a marker of apoptosis, therein. https://www.jove.com/v/53207 521 2016-01-13T01:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53628.jpg Ex Vivo Optogenetic Dissection of Fear Circuits in Brain Slices Optogenetic approaches are widely used to manipulate neural activity and assess the consequences for brain function. Here, a technique is outlined that upon in vivo expression of the optical activator Channelrhodopsin, allows for ex vivo analysis of synaptic properties of specific long range and local neural connections in fear-related circuits. https://www.jove.com/v/53628 673 2016-04-06T00:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53853.jpg Combined Optogenetic and Freeze-fracture Replica Immunolabeling to Examine Input-specific Arrangement of Glutamate Receptors in the Mouse Amygdala This article illustrates how the expression of neurotransmitter receptors can be quantified and the pattern analyzed at synapses with identified pre and postsynaptic elements using a combination of viral transduction of optogenetic tools and the freeze-fracture replica immunolabeling technique. https://www.jove.com/v/53853 589 2016-04-15T22:00:00+00:00 JoVE no https://visualize.jove.com/8474250-typogenetics-an-artificial-genetic-system monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10806.jpg What is Genetic Engineering? Overview Genetic engineering is the process of modifying an organism’s DNA to introduce new, desirable traits. Many organisms, from bacteria to plants and animals, have been genetically modified for academic, medical, agricultural, and industrial purposes. While genetic engineering has definite benefits, ethical concerns surround modifying humans and our food supply. Scientists can Deliberately Modify an Organism’s Genome Genetic engineering is possible because the genetic code—the way... https://www.jove.com/v/10806 49 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10809.jpg Transgenic Organisms Overview Transgenic organisms are genetically engineered to carry transgenes—genes from a different species—as part of their genome. The transgene may either be a different version of one of the organism’s genes or a gene that does not exist in their genome. Transgenes are usually generated by recombinant DNA and DNA cloning techniques. Transgenic bacteria, plants, and animals allow scientists to address biological queries and design practical solutions. Creating a Transgenic Organism <br... https://www.jove.com/v/10809 53 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10813.jpg In-vitro Mutagenesis To learn more about the function of a gene, researchers can observe what happens when the gene is inactivated or “knocked out,” by creating genetically engineered knockout animals. Knockout mice have been particularly useful as models for human diseases such as cancer, Parkinson’s disease, and diabetes. The Process Genes can be randomly knocked out, or specific genes can be targeted. To knock out a particular gene, an engineered piece of DNA called a targeting vector is used to replace the... https://www.jove.com/v/10813 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12025.jpg Genetic Screens Genetic screens are tools used to identify genes and mutations responsible for phenotypes of interest. Genetic screens help identify individuals or a group of people at risk of developing genetic diseases and help them with early intervention, targeted therapy, and reproductive options. Forward genetic screens Forward or “classical” genetic screens involve creating random mutations in an organism’s DNA using radiation, mutagens, or insertion of additional bases, which result in visible changes... https://www.jove.com/v/12025 166 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10809.jpg Transgenic Organisms Overview Transgenic organisms are genetically engineered to carry transgenes—genes from a different species—as part of their genome. The transgene may either be a different version of one of the organism’s genes or a gene that does not exist in their genome. Transgenes are usually generated by recombinant DNA and DNA cloning techniques. Transgenic bacteria, plants, and animals allow scientists to address biological queries and design practical solutions. Creating a Transgenic Organism <br... https://www.jove.com/v/12030 53 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12037.jpg Synthetic Biology Synthetic biology is an interdisciplinary science that involves using principles from disciplines such as engineering, molecular biology, cell biology, and systems biology. It involves remodeling existing organisms from nature or constructing completely new synthetic organisms for applications such as protein or enzyme production, bioremediation, value-added macromolecule production, and the addition of desirable traits to crops, to name a few. Golden rice Golden rice is a genetically modified... https://www.jove.com/v/12037 175 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51153.jpg Rapid Synthesis and Screening of Chemically Activated Transcription Factors with GFP-based Reporters This protocol describes an experimental procedure for the rapid construction of artificial transcription factors (ATFs) with cognate GFP reporters and quantification of the ATFs ability to stimulate GFP expression via flow cytometry. https://www.jove.com/v/51153 562 2013-11-27T04:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55765.jpg Generation of Genetically Modified Mice through the Microinjection of Oocytes The microinjection of mouse oocytes is commonly used for both classic transgenesis (i.e., the random integration of transgenes) and CRISPR-mediated gene targeting. This protocol reviews the latest developments in microinjection, with a particular emphasis on quality control and genotyping strategies. https://www.jove.com/v/55765 619 2017-06-15T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58268.jpg An Efficient Strategy for Generating Tissue-specific Binary Transcription Systems in Drosophila by Genome Editing Here, we present a method for generating tissue-specific binary transcription systems in Drosophila by replacing the first coding exon of genes with transcription drivers. The CRISPR/Cas9-based method places a transactivator sequence under the endogenous regulation of a replaced gene, and consequently facilitates transctivator expression exclusively in gene-specific spatiotemporal patterns. https://www.jove.com/v/58268 601 2018-09-19T22:00:00+00:00 JoVE no https://visualize.jove.com/8474455-localization-of-a-bidirectional-dna-replication-origin-in-the-native-locus-and-in-episomally-amplified-murine-adenosine-deaminase-loci monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4400.jpg Chromosome Replicating Timing Combined with Fluorescent In situ Hybridization A quantitative method for the analysis of chromosome replication timing is described. The method utilizes BrdU incorporation in combination with fluorescent in situ hybridization (FISH) to assess replication timing of mammalian chromosomes. This technique allows for the direct comparison of rearranged and un-rearranged chromosomes within the same cell. https://www.jove.com/v/4400 1034 2012-12-10T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11529.jpg Chromosome Structure A functional eukaryotic chromosome must contain three elements: a centromere, telomeres, and numerous origins of replication. The centromere is a DNA sequence that links sister chromatids. This is also where kinetochores, protein complexes to which spindle microtubules attach, are constructed after the chromosome is replicated. The kinetochores allow the spindle microtubules to move the chromosomes within the cell during cell division. Telomeres consist of non-coding repetitive nucleotide... https://www.jove.com/v/11529 160 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11530.jpg Chromosome Replication Before a cell can divide, it must accurately replicate all of its chromosomes, including the DNA and its associated histone and non-histone proteins. This process begins at numerous origins of replication during the S phase of the cell cycle in each of a cell’s chromosomes simultaneously. Certain nucleotides can act as origins of replication, but these sequences are not well defined - especially in complex, multi-cellular, eukaryotic species. The length of DNA that spans an origin of... https://www.jove.com/v/11530 151 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11548.jpg The DNA Replication Fork An organism’s genome needs to be duplicated in an efficient and error-free manner for its growth and survival. The replication fork is a Y-shaped active region where two strands of DNA are separated and replicated continuously. The coupling of DNA unzipping and complementary strand synthesis is a characteristic feature of a replication fork. Organisms with small circular DNA, such as E. coli, often have a single origin of replication; therefore, they have only two replication forks, one in... https://www.jove.com/v/11548 62 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11575.jpg Conservative Site-specific Recombination and Phase Variation Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines. The recognition sites for Cre recombinase called LoxP... https://www.jove.com/v/11575 173 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11993.jpg Exon Recombination The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes. Exon shuffling follows “splice frame rules.” Each exon has three reading... https://www.jove.com/v/11993 152 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13196.jpg Replication in Eukaryotes In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fulfill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus. Many Proteins Orchestrate Replication at the Origin Eukaryotic replication follows many of the same... https://www.jove.com/v/13196 89 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55946.jpg Determination of the Optimal Chromosomal Location(s) for a DNA Element in Escherichia coli Using a Novel Transposon-mediated Approach Here, the power of a transposon-mediated random insertion of a non-coding DNA element was used to resolve its optimal chromosomal position. https://www.jove.com/v/55946 672 2017-09-11T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67120.jpg Strand-Specific Analysis of Proteins at Replicating DNA Strands by Enrichment and Sequencing of Protein-Associated Nascent DNA Method Enrichment and sequencing of protein-associated nascent DNA (eSPAN) was developed to detect the relative abundance of a chromatin-associated protein on two replicating DNA strands, thereby revealing molecular insight into chromatin replication and its coupled processes. This protocol describes eSPAN procedures in yeast and mouse embryonic stem (ES) cells. https://www.jove.com/v/67120 533 2025-05-02T19:45:00+00:00 JoVE no https://visualize.jove.com/8489337-forensic-dna-testing monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2791.jpg A Noninvasive Hair Sampling Technique to Obtain High Quality DNA from Elusive Small Mammals We present a noninvasive sampling approach to efficiently collect hair samples from elusive small mammals, as shown for the American pika. We demonstrate the utility of this method by extracting DNA from sampled hair and amplifying several types of molecular markers commonly used in studies of wildlife ecology and conservation. https://www.jove.com/v/2791 460 2011-03-13T16:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12013.jpg Southern Blot Agarose gel electrophoresis is very useful in separating DNA fragments by size. Running a DNA ladder containing fragments of the known length alongside the sample helps determine the approximate length of the sample DNA fragments. However, additional steps are needed to verify the sequence identity of the sample DNA fragments. Denatured DNA fragments must be transferred onto a carrier membrane from the gel to make it accessible to a probe - a small ssDNA fragment complementary to the target DNA... https://www.jove.com/v/12013 177 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12016.jpg FISH - Fluorescent In-situ Hybridization Fluorescence in situ hybridization, or FISH, was developed in the early 1980s and has quickly become one of the most widely used techniques in cytogenetics. Labeled probes are used to bind complementary DNA or RNA sequences on a chromosome or in a region within a cell. Earlier, the probes could only be obtained by cloning or reverse transcription of a DNA template. Currently, the probe oligonucleotides can be synthesized synthetically. Additionally, with the advancement of optical techniques,... https://www.jove.com/v/12016 127 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52612.jpg Enhanced Genetic Analysis of Single Human Bioparticles Recovered by Simplified Micromanipulation from Forensic ‘Touch DNA’ Evidence Here we describe an optimized and efficient removal strategy for the collection of bio-particles present in ‘touch DNA’ samples, together with an enhanced amplification protocol involving a one-step 5 µl micro-volume lysis/STR amplification, to permit the recovery of short tandem repeat (STR) profiles of the bio-particle donor(s). https://www.jove.com/v/52612 709 2015-03-09T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62305.jpg Application of DNA Fingerprinting using the D1S80 Locus in Lab Classes Here we describe a simple protocol to generate DNA fingerprinting profiles by amplifying the VNTR locus D1S80 from epithelial cell DNA. https://www.jove.com/v/62305 515 2021-07-17T20:30:00+00:00 JoVE no https://visualize.jove.com/8507623-the-artificial-lens-implant monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14963.jpg Focusing of Light in the Eye Light rays enter the eye through the cornea, a transparent dome-shaped tissue that is the eye's outermost layer. The cornea bends or refracts, light rays traveling to the pupil. The shape of the cornea determines how much of the light is bent and whether the image will be focused correctly on the retina at the back of the eye. Once the light has passed through both refraction layers, it converges into a single focal point onto a small area. This is where photoreceptors start transforming... https://www.jove.com/v/14963 76 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50004.jpg Fiber-optic Implantation for Chronic Optogenetic Stimulation of Brain Tissue The development of optogenetics now provides the means to precisely stimulate genetically defined neurons and circuits, both in vitro and in vivo. Here we describe the assembly and implantation of a fiber optic for chronic photostimulation of brain tissue. https://www.jove.com/v/50004 618 2012-10-29T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58728.jpg In Vivo Targeted Expression of Optogenetic Proteins Using Silk/AAV Films Here, we present a method for delivering viral expression vectors into the brain using silk fibroin films. This method allows targeted delivery of expression vectors using silk/AAV coated optical fibers, tapered optical fibers, and cranial windows. https://www.jove.com/v/58728 371 2019-02-26T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67975.jpg Microfabrication of Implantable Optics Integrated in a Microstructured Imaging Window for Advanced In Vivo Imaging This protocol describes the fabrication of an implantable integrated imaging window using 3D laser printing. The window consists of a system of microlenses coupled with micro-scaffolds. The method involves two-photon polymerization (2PP) of the biocompatible photoresist SZ2080 in a continuous sequence, optimizing manufacturing efficiency and alignment between the different components. https://www.jove.com/v/67975 434 2025-04-11T21:30:00+00:00 JoVE no https://visualize.jove.com/8527697-computational-properties-of-self-reproducing-growing-automata monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11111.jpg Asexual Reproduction Asexual reproduction allows plants to reproduce without growing flowers, attracting pollinators, or dispersing seeds. Offspring are genetically identical to the parent and produced without the fusion of male and female gametes. Vegetative reproduction is a common type of asexual reproduction, in which detached fragments—such as stems, roots, or leaves—from individual plants develop into complete organisms. Dandelions of the Taraxacum genus use a method of asexual reproduction called apomixis,... https://www.jove.com/v/11111 158 2025-10-23T18:48:35+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12415.jpg Woodward–Hoffmann Selection Rules and Microscopic Reversibility Electrocyclic reactions, cycloadditions, and sigmatropic rearrangements are concerted pericyclic reactions that proceed via a cyclic transition state. These reactions are stereospecific and regioselective. The stereochemistry of the products depends on the symmetry characteristics of the interacting orbitals and the reaction conditions. Accordingly, pericyclic reactions are classified as either symmetry-allowed or symmetry-forbidden. Woodward and Hoffmann presented the selection criteria for... https://www.jove.com/v/12415 94 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13681.jpg Cyclic Processes And Isolated Systems A thermodynamic system with zero heat exchange and work is an isolated system. For these systems, the internal energy remains constant. In the case of a non-isolated system, the change in the internal energy is zero only if the process is cyclic. A thermodynamic process is considered cyclic if the system undergoes a series of changes and returns to its initial state. Consider a cyclic process that returns to its initial state, undergoing a four-step process. The heat transfer along each path... https://www.jove.com/v/13681 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13804.jpg Current Growth And Decay In RL Circuits The current growth and decay in RL circuits can be understood by considering a series RL circuit consisting of a resistor, an inductor, a constant source of emf, and two switches. When the first switch is closed, the circuit is equivalent to a single-loop circuit consisting of a resistor and an inductor connected to a source of emf. In this case, the source of emf produces a current in the circuit. If there were no self-inductance in the circuit, the current would rise immediately to a steady... https://www.jove.com/v/13804 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16045.jpg Classification of Systems-I Linearity is a system property characterized by a direct input-output relationship, combining homogeneity and additivity. Homogeneity dictates that if an input x(t) is multiplied by a constant c, the output y(t) is multiplied by the same constant. Mathematically, this is expressed as: Additivity means that the response to the sum of multiple inputs is the sum of their individual responses. For inputs x1(t) and x2(t) producing outputs y1(t) and y2(t), respectively: Combining homogeneity and... https://www.jove.com/v/16045 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16586.jpg Mechanistic Models: Compartment Models in Algorithms for Numerical Problem Solving Mechanistic models play a crucial role in algorithms for numerical problem-solving, particularly in nonlinear mixed effects modeling (NMEM). These models aim to minimize specific objective functions by evaluating various parameter estimates, leading to the development of systematic algorithms. In some cases, linearization techniques approximate the model using linear equations. In individual population analyses, different algorithms are employed, such as Cauchy's method, which uses a... https://www.jove.com/v/16586 89 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56422.jpg The Modular Design and Production of an Intelligent Robot Based on a Closed-Loop Control Strategy We present a protocol on modular design and production of intelligent robots to help scientific and technical workers design intelligent robots with special production tasks based on personal needs and individualized design. https://www.jove.com/v/56422 713 2017-10-14T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62997.jpg Automating Aggregate Quantification in Caenorhabditis elegans The following protocol describes the development and optimization of a high-throughput workflow for worm culturing, fluorescence imaging, and automated image processing to quantify polyglutamine aggregates as an assessment of changes in proteostasis. https://www.jove.com/v/62997 470 2021-10-14T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64539.jpg Gene Digital Circuits Based on CRISPR-Cas Systems and Anti-CRISPR Proteins CRISPR-Cas systems and anti-CRISPR proteins were integrated into the scheme of Boolean gates in Saccharomyces cerevisiae. The new small logic circuits showed good performance and deepened the understanding of both dCas9/dCas12a-based transcription factors and the properties of anti-CRISPR proteins. https://www.jove.com/v/64539 646 2022-10-18T22:00:00+00:00 JoVE no https://visualize.jove.com/8537485-an-easier-alternative-to-orthogonal-regression-for-calculation-of-international-sensitivity-indexes monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13628.jpg Regression Analysis Regression analysis is a statistical tool that describes a mathematical relationship between a dependent variable and one or more independent variables. In regression analysis, a regression equation is determined based on the line of best fit– a line that best fits the data points plotted in a graph. This line is also called the regression line. The algebraic equation for the regression line is called the regression equation. It is represented as: In the equation, is the dependent variable, x... https://www.jove.com/v/13628 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13630.jpg Residuals and Least-Squares Property The vertical distance between the actual value of y and the estimated value of y. In other words, it measures the vertical distance between the actual data point and the predicted point on the line If the observed data point lies above the line, the residual is positive, and the line underestimates the actual data value for y. If the observed data point lies below the line, the residual is negative, and the line overestimates the actual data value for y. The process of fitting the best-fit... https://www.jove.com/v/13630 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13634.jpg Multiple Regression Multiple regression assesses a linear relationship between one response or dependent variable and two or more independent variables. It has many practical applications. Farmers can use multiple regression to determine the crop yield based on more than one factor, such as water availability, fertilizer, soil properties, etc. Here, the crop yield is the response or dependent variable as it depends on the other independent variables. The analysis requires the construction of a scatter plot... https://www.jove.com/v/13634 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13642.jpg Introduction to Nonparametric Statistics Nonparametric statistics offer a powerful alternative to traditional parametric methods, useful when assumptions about the population distribution cannot be made. Unlike parametric tests, which require data to follow a specific distribution with well-defined parameters (such as the mean and standard deviation), nonparametric tests do not require such constraints. This makes them particularly valuable when dealing with small sample sizes, skewed data, or ordinal and categorical variables. One of... https://www.jove.com/v/13642 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17594.jpg Friedman Two-way Analysis of Variance by Ranks Friedman's Two-Way Analysis of Variance by Ranks is a nonparametric test designed to identify differences across multiple test attempts when traditional assumptions of normality and equal variances do not apply. Unlike conventional ANOVA, which requires normally distributed data with equal variances, Friedman's test is ideal for ordinal or non-normally distributed data, making it particularly useful for analyzing dependent samples, such as matched subjects over time or repeated measures from... https://www.jove.com/v/17594 81 JoVE no https://cloudfront.jove.com/files/ftp_upload/19805/19805_article_thumb_19805_TN.jpg Derivatives of Inverse Trigonometric Functions A ship tracking an approaching aircraft relies on geometric measurements to find out the aircraft’s position relative to the observer. By measuring the slant distance to the aircraft and the angle of elevation, the horizontal and vertical components of the distance can be obtained using trigonometric relationships. This geometric approach provides a basis for analyzing how the observed angle changes as the aircraft moves closer to the ship.To examine the mathematical behavior of the angle of... https://www.jove.com/v/19805 90 2026-01-12T20:24:15+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59077.jpg O-cresol Concentration Online Measurement Based On Near Infrared Spectroscopy Via Partial Least Square Regression The protocol describes a method of predicting o-cresol concentration during the production of polyphenylene ether using near-infrared spectroscopy and partial least squares regression. To describe the process more clearly and completely, an example of predicting the o-cresol concentration during the production of polyphenylene is used to clarify the steps. https://www.jove.com/v/59077 410 2019-11-08T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61965.jpg Calibration Procedures for Orthogonal Superposition Rheology We present a detailed calibration protocol for a commercial orthogonal superposition rheology technique using Newtonian fluids including end-effect correction factor determination methods and recommendations for best practices to reduce experimental error. https://www.jove.com/v/61965 523 2020-11-18T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64520.jpg Ecotoxicological Methodologies to Evaluate Biomarkers at Different Scales in Neotropical Anurans In this paper, standardized ecotoxicological methods for the evaluation of biomarkers in neotropical anuran species are presented. Specifically, this paper details several methodologies at different scales of ecotoxicological evaluation, such as the genetic, cellular-histological, biochemical, morphological, and individual levels. https://www.jove.com/v/64520 494 2023-04-28T21:50:00+00:00 JoVE no https://visualize.jove.com/8543905-right-aortic-arch-and-isolated-left-brachiocephalic-arterial-trunk-fortuitous-discovery-in-angiologic-practice monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/51374.jpg Accuracy in Dental Medicine, A New Way to Measure Trueness and Precision Accuracy is a major demand in dental medicine. To verify accuracy, reference scanners are needed. This article presents a new reference scanner with an adjusted scanning method to acquire a broad variety of dental morphologies with high trueness and precision. https://www.jove.com/v/51374 477 2014-04-29T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63627.jpg A Standardized Approach to Extra-Oral and Intra-Oral Digital Photography The present protocol describes a method to capture intra- and extra-oral photographs for digital documentation in the clinical practice of dentistry. The protocol highlights all the critical components involved and the commonly utilized settings to capture dental photographs for clinical documentation. https://www.jove.com/v/63627 409 2022-07-22T20:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65035.jpg Semi-Automated Planimetric Quantification of Dental Plaque Using an Intraoral Fluorescence Camera This study presents a semi-automated digital image analysis procedure for the planimetric quantification of disclosed dental plaque based on images acquired with an intraoral fluorescence camera. The method allows for the rapid and reliable quantification of dental plaque in the research environment. https://www.jove.com/v/65035 574 2023-01-27T23:00:00+00:00 JoVE no https://visualize.jove.com/8561533-atrial-activation-during-chronic-atrial-fibrillation-in-patients-with-isolated-mitral-valve-disease monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3103.jpg High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation This report provides a detailed description of the methodology and results of simultaneous endocardial and epicardial optical mapping of electrical excitation in the intact left atrium of a Langendorff-perfused sheep heart during stretch-induced atrial fibrillation. https://www.jove.com/v/3103 557 2011-07-29T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17892/17892_article_thumb_17892.jpg Mitral Valve Prolapse I: Introduction IntroductionThe mitral valve, one of the heart's four valves, regulates blood flow. These valves have flaps that open and close to direct blood properly through the heart and body. During each heartbeat, the flaps open for blood to pass through and seal shut to prevent backflow. Specifically, the mitral valve opens to allow blood flow from the heart's upper left chamber to the lower left chamber. It then closes securely as the lower left chamber contracts to pump blood to the body, preventing... https://www.jove.com/v/17892 87 2025-06-19T16:15:47+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17895/17895_article_thumb_17895.jpg Mitral Regurgitation I: Introduction Mitral regurgitation is characterized by the backward circulation of blood from the left ventricle to the left atrium during systole, a phase of the cardiac cycle when the heart contracts and pumps blood out of the chambers. This abnormal flow occurs primarily due to the dysfunction of the mitral valve or its supporting structures, which include the mitral leaflets, chordae tendineae, annulus, and papillary muscles.Etiology and Mechanisms:Primary Mitral Regurgitation: This type arises from... https://www.jove.com/v/17895 80 2025-06-19T16:16:44+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17896/17896_article_thumb_17896.jpg Mitral Regurgitation II: Clinical Features and Diagnostic Tests Mitral regurgitation (MR) is a valvular heart disorder in which the mitral valve fails to close tightly, allowing blood to leak backward into the heart. Understanding the clinical manifestations, assessment, diagnostic findings, and medical management of MR is crucial to effectively managing affected patients.Clinical Manifestations of Mitral RegurgitationMitral regurgitation can be acute or chronic, each presenting differently and requiring different approaches:1. Acute Mitral... https://www.jove.com/v/17896 83 2025-06-19T16:17:06+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17899/17899_article_thumb_17899.jpg Mitral Stenosis I: Introduction Mitral Valve Stenosis (MVS) is a heart condition where the mitral valve narrows, impeding blood circulation from the left atrium to the left ventricle. The etiology and pathophysiology of this condition are multifaceted, leading to a cascade of cardiovascular complications.Causes of Mitral Valve StenosisRheumatic Heart Disease: It is the main cause of mitral valve stenosis, particularly in developing nations. This condition arises from rheumatic fever, an inflammatory illness resulting from... https://www.jove.com/v/17899 82 2025-06-19T16:18:36+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17900/17900_article_thumb_17900.jpg Mitral Stenosis II: Clinical features and Diagnostic Tests Mitral stenosis is a heart condition in which the mitral valve, which allows blood to flow from the left atrium to the left ventricle, becomes narrowed or stenotic. This narrowing hinders blood flow and leads to clinical symptoms requiring specific medical evaluations and management strategies. The following overview outlines the clinical symptoms, assessments, diagnostic findings, prevention methods, and treatments for mitral stenosis.Clinical ManifestationsDyspnea (shortness of breath): This... https://www.jove.com/v/17900 83 2025-06-19T16:18:57+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17901/17901_article_thumb_17901.jpg Mitral Stenosis III: Medical Management Mitral stenosis, a condition marked by the narrowing of the mitral valve, necessitates an integrated approach for effective management. This approach includes preventative measures, medical therapy, and surgical interventions to reduce symptoms and prevent complications.PreventionPrevention of mitral stenosis primarily focuses on reducing the incidence of bacterial infections, particularly streptococcal infections, which can lead to rheumatic fever and subsequent valvular damage. Timely... https://www.jove.com/v/17901 86 2025-06-19T16:19:22+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63094.jpg Sterile Pericarditis in Aachener Minipigs As a Model for Atrial Myopathy and Atrial Fibrillation We describe a sterile pericarditis model in minipigs to study atrial myopathy and atrial fibrillation (AF). We present surgical and anesthetic techniques, strategies for vascular access, and a protocol to study the inducibility of AF. https://www.jove.com/v/63094 536 2021-09-24T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63598.jpg Estimating Bilateral Atrial Function by Cardiovascular Magnetic Resonance Feature Tracking in Patients with Paroxysmal Atrial Fibrillation The atrial function is associated with the strain and strain rate. The cardiac magnetic resonance feature tracking (CMR-FT) technique was used in this study to quantify left and right atrial global and segmental longitudinal strain and strain rate in individuals with paroxysmal atrial fibrillation. https://www.jove.com/v/63598 490 2022-07-20T19:45:00+00:00 JoVE no https://visualize.jove.com/8569429-biodiscrimination-of-alpha-tocopherol-stereoisomers-during-intestinal-absorption monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3399.jpg Cellular Lipid Extraction for Targeted Stable Isotope Dilution Liquid Chromatography-Mass Spectrometry Analysis This protocol will demonstrate the extraction and analysis of free and esterified bioactive fatty acids from cells. Fatty acids are accurately quantified using stable isotope dilution, chiral liquid chromatography, electron capture atmospheric chemical ionization multiple reaction monitoring mass spectrometry (SID-LC-ECAPCI-MRM/MS). https://www.jove.com/v/3399 566 2011-11-17T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14398.jpg Drug Absorption: Factors Affecting GI Absorption The process of oral drug absorption can be influenced by several factors. Weakly acidic drugs tend to be absorbed more readily from the stomach due to their nonionized state. However, absorption may be less efficient in the upper intestine, where drugs are often ionized. Interestingly, despite the stomach's apparent advantage for drug absorption, its mucous layer can hinder diffusion. Its surface area is also smaller than the intestine's, which can further slow down the absorption rate. In... https://www.jove.com/v/14398 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14400.jpg Factors Influencing Bioavailability: First-Pass Elimination When a drug is taken orally, it undergoes a journey starting from the gastrointestinal (GI) tract, passing through the portal vein, reaching the liver, and finally entering the systemic circulation. This process involves the absorption of the drug across the GI tract. The liver is the primary site for metabolizing the drug, with some metabolism also occurring in the gut wall. This journey significantly reduces the quantity of the drug that reaches the systemic circulation, a phenomenon known as... https://www.jove.com/v/14400 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16510.jpg Factors Affecting Dissolution: Drug Permeability, Stability and Stereochemistry Orally administered drugs primarily enter the systemic circulation via passive diffusion through the intestinal membranes. The drug's absorption is influenced by drug stability in the gastrointestinal GI tract, membrane permeability, the surface area available for absorption, luminal drug concentration, and residence time in the lumen. Drug permeability can be enhanced by adjusting the lipophilicity, polarity, or molecular size of the drug, promoting its passive transport across intestinal... https://www.jove.com/v/16510 80 JoVE no https://cloudfront.jove.com/files/ftp_upload/17143/17143_article_thumb_17143.jpg Bioavailability: Influencing Factors Bioavailability refers to the extent and rate at which a drug reaches systemic circulation in its active form. Extent refers to the amount of the drug that makes it into circulation, while rate is the speed at which it enters circulation. It is influenced by several factors critical for optimizing drug formulations, dosing regimens, and therapeutic outcomes.Physicochemical properties of drugs and formulationsThe solubility, stability, and dissolution rate of a drug significantly impact its... https://www.jove.com/v/17143 82 2025-10-03T14:00:43+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17144/17144_article_thumb_17144.jpg Bioavailability Study Design: Absolute Versus Relative Bioavailability Bioavailability is a crucial pharmacokinetic parameter that quantifies the proportion of an administered drug that reaches the systemic circulation and is available for therapeutic action. Regulatory agencies mandate the assessment of bioavailability, typically measured as the area under the drug plasma concentration-versus-time curve (AUC), to ensure the efficacy and safety of pharmaceutical products. These evaluations are categorized as absolute and relative bioavailability studies.Absolute... https://www.jove.com/v/17144 87 2025-10-03T14:00:42+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17226/17226_article_thumb_17226.jpg Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase Genetic polymorphisms in drug targets have emerged as critical determinants of interindividual variability in drug response and toxicity. Pharmacogenomic investigations increasingly focus on identifying these variations to personalize and optimize therapeutic interventions. A drug target may be a receptor, enzyme, or signaling protein involved in pharmacologic responses or disease-related pathways. While early pharmacogenetic studies focused primarily on drug metabolism, current research... https://www.jove.com/v/17226 71 2026-02-12T19:16:57+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54597.jpg Using Multi-fluorinated Bile Acids and In Vivo Magnetic Resonance Imaging to Measure Bile Acid Transport Tools to diagnose bile acid malabsorption and measure bile acid transport in vivo are limited. An innovative approach in live animals is described that utilizes combined proton (1H) plus fluorine (19F) magnetic resonance imaging; this novel methodology has translational potential to screen for bile acid malabsorption in clinical practice. https://www.jove.com/v/54597 522 2016-11-27T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67034.jpg Quantitative Analysis of Dietary Vitamin A Metabolites in Murine Ocular and Non-Ocular Tissues Using High-Performance Liquid Chromatography Here, a normal-phase, high-performance liquid chromatography method is described to detect and quantify critical retinoids involved in the facilitation of visual function in both ocular and systemic tissue, in the context of the systemic vitamin A supply to generate the essential photosensitive rhodopsin chromophore 11-cis-retinal. https://www.jove.com/v/67034 303 2024-12-27T20:00:00+00:00 JoVE no https://visualize.jove.com/8575641-ontogeny-of-basal-and-regulated-secretion-from-pomc-cells-of-the-developing-anterior-lobe-of-the-rat-pituitary-gland monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10719.jpg Endocrine Signaling Endocrine cells produce hormones to communicate with remote target cells found in other organs. The hormone reaches these distant areas using the circulatory system. This exposes the whole organism to the hormone but only those cells expressing hormone receptors or target cells are affected. Thus, endocrine signaling induces slow responses from its target cells but these effects also last longer. There are two types of endocrine receptors: cell surface receptors and intracellular receptors. https://www.jove.com/v/10719 105 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11892.jpg Overview of Secretory Vesicles Secretory vesicles, also known as dense core vesicles (DCVs), are membrane-bound vesicles that transport secretory proteins, such as hormones or neurotransmitters. Regulated secretory vesicles transport proteins from the trans-Golgi network to the exterior of the cell. Proteins present in regulated secretory vesicles are required to be rapidly exocytosed in large amounts upon a specific stimulus. Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins... https://www.jove.com/v/11892 93 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12220.jpg Insulin Secretory Vesicles Insulin secretory vesicles release insulin to stimulate blood glucose uptake and regulate carbohydrate metabolism. When the blood glucose levels increase, glucose enters the pancreatic β-islet cells through glucose transporters. Once inside, glucose is metabolized through glycolysis, the citric acid cycle, and the electron transport chain, producing ATP. This increase in ATP concentration closes ATP-sensitive potassium channels, leading to depolarization of the membrane and the opening of... https://www.jove.com/v/12220 65 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14978.jpg Regulation of Hormone Secretion Regulation of hormone secretion is a finely tuned orchestration driven by various types of stimuli, encompassing neural, humoral, and hormonal signals. Environmental cues instigate neural stimuli, where action potentials traverse nerve fibers to reach their designated targets. An illustrative scenario is the body's response to stress, wherein the sympathetic nervous system releases epinephrine from the adrenal glands, inducing the well-known 'fight or flight' reaction. Humoral stimuli,... https://www.jove.com/v/14978 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14979.jpg The Pituitary Gland The pituitary is a small endocrine organ in the sphenoid bone under the hypothalamus. Primarily, the pituitary in adults has two distinct anatomical and functional regions— the anterior and posterior lobes. During human fetal development, a third pituitary gland region called the pars intermedia atrophies and disappears. However, some of its cells migrate and exist adjacent to the anterior pituitary in adults. The anterior lobe comprises the pars distalis and the pars tuberalis. These areas... https://www.jove.com/v/14979 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14980.jpg Hormones of the Pituitary Gland The small, pea-sized pituitary gland is located at the base of the brain. It is crucial in regulating various bodily functions, from growth to reproduction. The gland is divided into the anterior lobe and the posterior lobe. The secretory cell clusters in the pars distalis of the anterior pituitary lobe are controlled by hypothalamic regulators and synthesize six primary hormones. The most abundantly secreted hormone from the anterior lobe is the growth hormone, which controls overall growth by... https://www.jove.com/v/14980 87 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56356.jpg Dissection and Coronal Slice Preparation of Developing Mouse Pituitary Gland We present a protocol to dissect pituitary glands and prepare pituitary coronal sections from developing mice. https://www.jove.com/v/56356 413 2017-11-16T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57599.jpg Generation of Scaffold-free, Three-dimensional Insulin Expressing Pancreatoids from Mouse Pancreatic Progenitors In Vitro Here, we present a protocol to generate insulin expressing 3D murine pancreatoids from free-floating e10.5 dissociated pancreatic progenitors and the associated mesenchyme. https://www.jove.com/v/57599 573 2018-06-02T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63431.jpg Development of Organoids from Mouse Pituitary as In Vitro Model to Explore Pituitary Stem Cell Biology The pituitary gland is the key regulator of the body's endocrine system. This article describes the development of organoids from the mouse pituitary as a novel 3D in vitro model to study the gland's stem cell population of which the biology and function remain poorly understood. https://www.jove.com/v/63431 588 2022-02-25T22:30:00+00:00 JoVE no https://visualize.jove.com/8591199-a-proposed-architecture-for-ambulatory-systems-development monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12965.jpg Methods Of Healthcare Delivery System At the different levels of the healthcare system, we see varying methods of healthcare used. These methods include managed care systems, case management, and primary healthcare. Managed Care System: The managed care system is designed to control the cost while maintaining the quality of care. The patient's care from admission to discharge is planned by the primary care provider or the case manager, also known as the gatekeeper. In a managed care system, the number of care providers is limited... https://www.jove.com/v/12965 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12970.jpg Tertiary Healthcare System Specialized care provided over an extended period is called tertiary care. Usually, a primary or secondary care physician will refer a patient to tertiary care. A patient's maximum physical and mental function is restored in tertiary care, which is caused due to the impact of a chronic illness or condition. Tertiary care aims to achieve the highest level of functioning possible while managing chronic illness. For example, a patient who falls and fractures their hip will need secondary care to... https://www.jove.com/v/12970 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13106.jpg Integrated Healthcare System An integrated healthcare system (IHS) is a set of organizations that provides for or arranges to provide coordinated and continuous service to a defined population. The IHS takes responsibility for that particular population's health status and outcome, both clinically and fiscally. An integrated healthcare system is a well-organized, well-coordinated, and collaborative network. The integrated delivery system is a network that connects different healthcare providers to deliver organized,... https://www.jove.com/v/13106 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14114.jpg Methods of Documentation VI: Case Management Model The case management model is a multidisciplinary approach that involves healthcare professionals from diverse disciplines, such as physicians, nurses, therapists, social workers, and pharmacists, working collaboratively to address the various needs of patients. Each healthcare professional brings unique expertise and perspectives, contributing to a more comprehensive understanding of the patient's condition and tailoring treatment plans accordingly. For example, a patient with a chronic illness... https://www.jove.com/v/14114 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14124.jpg Documentation in Long-Term and Home Healthcare Setting Documentation in long-term care facilities and home healthcare settings is crucial for ensuring continuous, coordinated, and comprehensive care for patients. Each setting has its specific documentation processes and tools: Long-Term Care Facilities • Purpose: Documentation in long-term care facilities is critical for interprofessional resident assessment and planning. It ensures that all aspects of a resident's care - from medical needs to daily living assistance - are thoroughly monitored... https://www.jove.com/v/14124 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14125.jpg Health Information Technology and Healthcare Information System Health Information Technology (HIT) Health Information Technology, commonly called HIT, integrates advanced information systems and technology in healthcare settings. Its primary functions include: Documentation and Monitoring of Patient Care: HIT systems facilitate the efficient recording and tracking of patient data, aiding healthcare providers in monitoring patients' health status and making informed decisions. Managerial and Organizational Functions: Beyond patient care, HIT is... https://www.jove.com/v/14125 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56942.jpg Methodology for Establishing a Community-Wide Life Laboratory for Capturing Unobtrusive and Continuous Remote Activity and Health Data Unobtrusive sensors and pervasive computing technology incorporated into the daily home life of older adults enables meaningful health and activity changes to be recorded continuously for months to years, providing ecologically valid, high frequency, multi-domain data for research or clinical use. https://www.jove.com/v/56942 681 2018-07-27T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61899.jpg Digital Home-Monitoring of Patients after Kidney Transplantation: The MACCS Platform The MACCS platform is a comprehensive telemedicine concept aiming at better outcomes after kidney transplantation by sharing key medical information between patients and physicians. A telemedicine team reviews incoming data to detect potential complications and to improve adherence in kidney transplant recipients to achieve better long-term outcomes. https://www.jove.com/v/61899 433 2021-04-12T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67040.jpg Workflow and Framework for Collecting and Implementing Point-of-Care Ultrasound Data in the Management of Heart Failure Patients This protocol presents a scalable workflow for the use of point-of-care ultrasound in the management of hospitalized and outpatient heart failure patients. https://www.jove.com/v/67040 227 2024-07-12T21:45:00+00:00 JoVE no https://visualize.jove.com/8637926-cortical-oscillations-and-the-origin-of-express-saccades monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12764.jpg Oscillations about an Equilibrium Position Stability is an important concept in oscillation. If an equilibrium point is stable, a slight disturbance of an object that is initially at the stable equilibrium point will cause the object to oscillate around that point. For an unstable equilibrium point, if the object is disturbed slightly, it will not return to the equilibrium point. There are three conditions for equilibrium points—stable, unstable, and half-stable. A half-stable equilibrium point is also unstable, but is named so because... https://www.jove.com/v/12764 64 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12771.jpg Forced Oscillations When an oscillator is forced with a periodic driving force, the motion may seem chaotic. The motions of such oscillators are known as transients. After the transients die out, the oscillator reaches a steady state, where the motion is periodic, and the displacement is determined. Using the equations of force and motion, the amplitude of the driven oscillator is obtained. It depends on the natural and driving frequency. In the equation for amplitude, when the driving frequency is much smaller... https://www.jove.com/v/12771 66 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13108.jpg Mechanism of Ciliary Motion The ciliary structures were first seen in 1647 by Antonie Leeuwenhoek while observing the protozoans. In lower organisms, these appendages are responsible for cell movement, while in higher organisms, these appendages help in the movement of the extracellular fluids within the body cavities. The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are... https://www.jove.com/v/13108 65 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13108.jpg Mechanism of Ciliary Motion The ciliary structures were first seen in 1647 by Antonie Leeuwenhoek while observing the protozoans. In lower organisms, these appendages are responsible for cell movement, while in higher organisms, these appendages help in the movement of the extracellular fluids within the body cavities. The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are... https://www.jove.com/v/13927 65 JoVE no https://cloudfront.jove.com/files/ftp_upload/14894/14894_article_thumb_14894.jpg Propagation of Action Potentials The propagation of an action potential refers to the process by which a nerve impulse, or "action potential," travels along a neuron. Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to... https://www.jove.com/v/14894 83 2025-08-11T22:39:58+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14935.jpg Major Somatic Sensory Pathways Sensory impulses related to touch, pressure, vibration, and proprioception from various body parts, such as the limbs, trunk, neck, and posterior head, travel to the cerebral cortex through the posterior column-medial lemniscus pathway. The pathway’s name derives from the two white-matter tracts that convey the impulses: the spinal cord's posterior column and the brainstem's medial lemniscus. First-order sensory neurons extend their axons into the spinal cord, forming the posterior columns... https://www.jove.com/v/14935 88 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53640.jpg Using Saccadometry with Deep Brain Stimulation to Study Normal and Pathological Brain Function This paper describes the use of quantitative measurement of eye movements in conjunction with stimulation of focal areas of the deep brain in order to study physiology, pathophysiology, and the mechanisms of deep brain stimulation. https://www.jove.com/v/53640 344 2016-07-14T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56934.jpg Recording Horizontal Saccade Performances Accurately in Neurological Patients Using Electro-oculogram The article describes a practical method for recording horizontal eye movements with high accuracy by electro-oculogram in neurological patients, using a cup Ag-AgCl electrode with a wide plastic fringe. Stable measurement requires proper selection and fixation of electrodes, taking sufficient time for light adaptation to occur, and re-calibration as needed. https://www.jove.com/v/56934 372 2018-03-13T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59162.jpg Investigating the Deployment of Visual Attention Before Accurate and Averaging Saccades via Eye Tracking and Assessment of Visual Sensitivity This experimental protocol combined eye tracking and the assessment of presaccadic visual sensitivity in a dual task paradigm, consisting of a free choice saccade task and a visual discrimination task, to investigate the deployment of visual spatial attention before both, accurate and averaging saccades. https://www.jove.com/v/59162 406 2019-03-18T21:30:00+00:00 JoVE no https://visualize.jove.com/8653925-a-computer-program-that-periodically-monitors-the-ability-to-interpret-the-antinuclear-antibody-test monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/51211.jpg Anti-Nuclear Antibody Screening Using HEp-2 Cells Indirect immunofluorescent (IIF) assays have traditionally been used for the detection of antinuclear antibodies (ANA) in human serum. The presence of these antibodies can aid in the diagnosis of systemic autoimmune rheumatic diseases (SARD). This protocol demonstrates how to effectively perform the IIF technique to accurately detect these autoantibodies. https://www.jove.com/v/51211 781 2014-06-24T01:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56722.jpg Simultaneous Distinction of Monospecific and Mixed DFS70 Patterns During ANA Screening with a Novel HEp-2 ELITE/DFS70 Knockout Substrate DFS70 autoantibodies mimic common disease-associated antinuclear antibody patterns making accurate interpretation challenging when using conventional HEp-2 substrates. The protocol describes advantages of novel engineered HEp-2 substrate over conventional HEp-2 in ANA screening and distinguishing DFS70 patterns with high confidence in both monospecific and mixed ANA positive cases. https://www.jove.com/v/56722 605 2018-01-17T18:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57777.jpg Detection of Antibodies That Neutralize the Cellular Uptake of Enzyme Replacement Therapies with a Cell-based Assay Here we present a cell-based flow cytometry method to detect neutralizing antibodies or other factors that interfere with the cellular uptake of enzyme replacement therapies in a human matrix, such as cerebral spinal fluid (CSF) or human serum. https://www.jove.com/v/57777 472 2018-09-10T20:00:00+00:00 JoVE no https://visualize.jove.com/8683187-childrens-performance-on-animal-tests-of-oddity-implications-for-cognitive-processes-required-for-tests-of-oddity-and-delayed-nonmatch-to-sample monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/51944.jpg The Attentional Set Shifting Task: A Measure of Cognitive Flexibility in Mice The goal of this protocol is to perform a behavioral assay such as the attentional set shifting task (AST) to assess prefrontal cortex-mediated cognitive flexibility in mice. https://www.jove.com/v/51944 555 2015-02-04T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53503.jpg An Operant Intra-/Extra-dimensional Set-shift Task for Mice Attentional set-shifting cognitive abnormalities are a core feature of many psychiatric diseases. Here, we present the development of a novel automatic system for the effective study of attentional set-shifting abilities, executive functions and other cognitive abilities in mice with high translational validity to human studies. https://www.jove.com/v/53503 515 2016-01-22T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57489.jpg Testing for Metacognitive Responding Using an Odor-based Delayed Match-to-Sample Test in Rats This protocol describes a method for investigating the possibility of metamemory, or memory awareness, in rodents. The odor-based delayed-matching-to-sample paradigm is a novel, ecologically-relevant behavioral test useful for determining the extent to which rodents can adaptively respond based on cognitively monitoring the strength of their memory states. https://www.jove.com/v/57489 486 2018-06-18T20:30:00+00:00 JoVE no https://visualize.jove.com/8734516-cross-scale-information-processing-in-evolution-development-and-intelligence monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4375.jpg Perceptual and Category Processing of the Uncanny Valley Hypothesis' Dimension of Human Likeness: Some Methodological Issues Investigation of the Uncanny Valley Hypothesis and affective experience requires an understanding of the hypothesis' dimension of human likeness (DHL). This protocol allows representation of the DHL and examination of categorical perception. Use of the same stimuli and fMRI to distinguish brain regions responsive to physical and category change is illustrated. https://www.jove.com/v/4375 454 2013-06-03T15:58:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12608.jpg Introduction to Scalers Many familiar physical quantities can be specified completely by giving a single number and the appropriate unit. For example, "a class period lasts 50 min," or "the gas tank in my car holds 65 L," or "the distance between the two posts is 100 m." A physical quantity that can be specified completely in this manner is called a scalar quantity. The word "scalar" is a synonym for "number." Time, mass, distance, length, volume, temperature, and energy are some examples of scalar quantities. Scalar... https://www.jove.com/v/15555 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17762.jpg Evolutionary Psychology Evolutionary psychology explores the origins of human behavior and mental processes by framing them within the context of natural selection, a theory famously propounded by Charles Darwin. This field asserts that many behaviors common across human societies — ranging from instinctive fear reactions to complex social interactions — arose as evolutionary adaptations. These adaptations enhanced the survival and reproductive success of our ancestors, thereby becoming embedded in the human psyche... https://www.jove.com/v/17762 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17779.jpg Parallel Processing The brain processes sensory information rapidly due to parallel processing, which involves sending data across multiple neural pathways at the same time. This method allows the brain to manage various sensory qualities, such as shapes, colors, movements, and locations, all concurrently. For instance, when observing a forest landscape, the brain simultaneously processes the movement of leaves, the shapes of trees, the depth between them, and the various shades of green. This enables a quick and... https://www.jove.com/v/17779 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18158.jpg Intelligence The term "intelligence" is complex because it refers to both behavior and individuals, and its interpretation varies across cultures. European Americans tend to link intelligence with reasoning and cognitive skills, while in Kenya, it is tied to responsible participation in family and social life. In Uganda, intelligence is seen as the ability to know the right actions and carry them out effectively, while the Iatmul people of Papua New Guinea associate it with the capacity to remember detailed... https://www.jove.com/v/18158 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18166.jpg Biological Influences on Intelligence Intelligence is often thought to be linked to brain size, but the relationship is more complex than that. While brain size does correlate modestly with some abilities, like verbal skills, the connection is weaker for others, such as spatial reasoning. Other factors, like brain structure, also play crucial roles. For instance, despite Einstein's smaller-than-average brain, his parietal cortex, which is involved in spatial reasoning, was 15% wider, suggesting that neural density might matter more... https://www.jove.com/v/18166 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18562.jpg Information Processing Approach The information-processing theory of cognitive development centers on fundamental mental processes, including attention, memory, and problem-solving skills. Researchers in this field examine how cognitive abilities, such as working memory, evolve and influence children's overall development. Studies indicate that children with stronger working memory tend to excel in reading comprehension, math, and problem-solving compared to peers with less efficient memory skills. Low working memory is also... https://www.jove.com/v/18562 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56292.jpg Quantification of Information Encoded by Gene Expression Levels During Lifespan Modulation Under Broad-range Dietary Restriction in C. elegans Here, we present a framework to relate broad-range dietary restriction to gene expression and lifespan. We describe protocols for broad-range dietary restriction and for quantitative imaging of gene expression under this paradigm. We further outline computational analyses to reveal underlying information processing features of the genetic circuits involved in food-sensing. https://www.jove.com/v/56292 563 2017-08-16T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68668.jpg Decoding Natural Behavior from Neuroethological Embedding This protocol gives an integrated framework based on advanced computational neuroethological methods to understand brain coding in naturalistic contexts. https://www.jove.com/v/68668 480 2025-10-03T20:40:00+00:00 JoVE no https://visualize.jove.com/8737892-adult-rat-vigilance-states-discrimination-by-artificial-neural-networks-using-a-single-eeg-channel monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3685.jpg A Fully Automated and Highly Versatile System for Testing Multi-cognitive Functions and Recording Neuronal Activities in Rodents In this report, we present a fully automated and highly versatile system capable of simultaneously testing multi-cognitive behaviors and recording neuronal activities for rodents. https://www.jove.com/v/3685 553 2012-05-03T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52700.jpg Brain Source Imaging in Preclinical Rat Models of Focal Epilepsy using High-Resolution EEG Recordings This video introduces the preparation, recording, and source analysis procedures of high-resolution EEG on sedated rats with a particular preclinical model of focal epilepsy under noninvasive conditions. https://www.jove.com/v/52700 500 2015-06-06T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54160.jpg Implantation and Recording of Wireless Electroretinogram and Visual Evoked Potential in Conscious Rats We show surgical implantation and Recording procedures to measure visual electrophysiological signals from the eye (electroretinogram) and brain (visual evoked potential) in conscious rats, which is more analogous to the human condition where recordings are conducted without anesthesia confounds. https://www.jove.com/v/54160 682 2016-06-29T22:00:00+00:00 JoVE no https://visualize.jove.com/8748761-cavernous-angioma-associated-with-oligo-astrocytoma-like-proliferation-report-of-two-cases-and-review-of-the-literature-with-a-reappraisal-of-the-term-angioglioma monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12509.jpg Mechanism of Angiogenesis Blood vessel formation starts early during embryonic development, around day 7. In the extraembryonic yolk sac, mesodermal precursor cells called hemangioblast proliferate and differentiate into angioblast. Angioblasts express vascular endothelial growth factor receptor 2 or VEGFR2, which binds VEGF-A, a proangiogenic factor, guiding blood vessel formation. VEGF signaling promotes angioblasts to form a blood island in the developing embryo. Angioblasts further differentiate, giving rise to... https://www.jove.com/v/12509 70 JoVE no https://cloudfront.jove.com/files/ftp_upload/17980/17980_article_thumb_17980.jpg Aneurysm II: Clinical Manifestations and Diagnostic Studies Thoracic, aortic arch and abdominal aneurysms are significant vascular conditions that can present with various clinical manifestations and lead to serious complications. Understanding these manifestations and the appropriate diagnostic studies is essential for effective management and treatment.Thoracic Aortic AneurysmsThoracic aortic aneurysms often remain asymptomatic until they reach a size that impinges on adjacent structures. They typically cause deep, diffuse chest pain that radiates to... https://www.jove.com/v/17980 81 2025-06-19T16:19:14+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50865.jpg Primary Orthotopic Glioma Xenografts Recapitulate Infiltrative Growth and Isocitrate Dehydrogenase I Mutation Malignant gliomas constitute a heterogeneous group of highly infiltrative glial neoplasms with distinct clinical and molecular features. Primary orthotopic xenografts recapitulate the histopathological and molecular features of malignant glioma subtypes in preclinical animal models. https://www.jove.com/v/50865 583 2014-01-14T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55522.jpg Comprehensive Endovascular and Open Surgical Management of Cerebral Arteriovenous Malformations Surgery is the gold standard for accessible arteriovenious malformations (AVMs), and pre-operative embolization can simplify this procedure. We describe our approach for staged endovascular embolization and open resection of AVMs, and provide a representative clinical example highlighting the advantages of a comprehensively trained neurovascular surgeon leading a multi-disciplinary clinical team. https://www.jove.com/v/55522 898 2017-10-20T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/69547.jpg Preparation Of Neovascular Tissues from Human Glioma Tissues for Quantitative Proteomics Analysis of Tumor Angiogenesis This protocol successfully prepared sufficient high-quality neovascular tissue from glioma samples using laser-capture microdissection for quantitative proteomics analysis of tumor angiogenesis, overcoming the limitations of studies that traditionally focus mainly on angiogenic factors and providing a large-scale proteomics profile of glioma angiogenesis. https://www.jove.com/v/69547 573 2026-03-20T21:20:00+00:00 JoVE no https://visualize.jove.com/8787201-development-of-oscillatory-activity-in-the-limbic-cortex-in-vitro monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2949.jpg Multi-electrode Array Recordings of Neuronal Avalanches in Organotypic Cultures A robust way to study neuronal avalanches, i.e. scale-invariant spatio-temporal activity bursts, indicative of critical state dynamics in cortex. Avalanches emerge spontaneously in developing superficial layers of cultured cortex which allows for long-term measurements of the activity with planar integrated multi-electrode arrays (MEA) under precisely controlled conditions. https://www.jove.com/v/2949 961 2011-08-01T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52877.jpg Generation of Local CA1 γ Oscillations by Tetanic Stimulation Oscillations are fundamental network properties and are modulated by disease and drugs. Studying brain-slice oscillations allows characterization of isolated networks under controlled conditions. Protocols are provided for the preparation of acute brain slices for evoking CA1 γ oscillations. https://www.jove.com/v/52877 482 2015-08-14T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55851.jpg Tuning in the Hippocampal Theta Band In Vitro : Methodologies for Recording from the Isolated Rodent Septohippocampal Circuit Here, we present a protocol for recording rhythmic neuronal network theta and gamma oscillations from an isolated whole hippocampal preparation. We describe the experimental steps from extraction of the hippocampus to details of field, unitary and whole-cell patch clamp recordings as well as optogenetic pacing of the theta rhythm. https://www.jove.com/v/55851 697 2017-08-02T20:00:00+00:00 JoVE no https://visualize.jove.com/8790978-error-models-and-quality-control-performance monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13618.jpg Testing a Claim about Standard Deviation A complete procedure to test a claim about population standard deviation or population variance is explained here. The hypothesis testing for the claim of population standard deviation (or variance) requires the data and samples to be random and unbiased. The population distribution also must be normal. There is no specific requirement on the sample size as the estimation is based on the chi-square distribution. As a first step, the hypothesis (null and alternative) concerning the claim about... https://www.jove.com/v/13618 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14505.jpg Statistical Analysis: Overview When we take repeated measurements on the same or replicated samples, we will observe inconsistencies in the magnitude. These inconsistencies are called errors. To categorize and characterize these results and their errors, the researcher can use statistical analysis to determine the quality of the measurements and/or suitability of the methods. One of the most commonly used statistical quantifiers is the mean, which is the ratio between the sum of the numerical values of all results and the... https://www.jove.com/v/14505 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14517.jpg Detection of Gross Error: The Q Test When one or more data points appear far from the rest of the data, there is a need to determine whether they are outliers and whether they should be eliminated from the data set to ensure an accurate representation of the measured value. In many cases, outliers arise from gross errors (or human errors) and do not accurately reflect the underlying phenomenon. In some cases, however, these apparent outliers reflect true phenomenological differences. In these cases, we can use statistical methods... https://www.jove.com/v/14517 60 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14763.jpg Quality Control Quality control is one of the three cyclical quality assurance activities that help keep a system under statistical control. Typical quality control activities include creating quality control charts, conducting proficiency testing, and documenting and archiving results. Quality control helps track data, visualize trends, and identify variations, making it easier to detect deviations that may affect the accuracy of an analysis. One way to do this is by generating a quality control chart, which... https://www.jove.com/v/14763 65 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14764.jpg Quality Assurance Quality assurance is the overarching term used to describe the activities employed to ensure the proper performance of a system. These activities can be classified into three categories: quality control, quality assessment, and internal corrective measures. Typically, these activities work cyclically: quality control is performed before and during the analysis, while quality assessment occurs during and after the investigation. Internal corrective measures are implemented based on the findings... https://www.jove.com/v/14764 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16480.jpg Accuracy and Errors in Hypothesis Testing Hypothesis testing is a fundamental statistical tool that begins with the assumption that the null hypothesis H0 is true. During this process, two types of errors can occur: Type I and Type II. A Type I error refers to the incorrect rejection of a true null hypothesis, while a Type II error involves the failure to reject a false null hypothesis. In hypothesis testing, the probability of making a Type I error, denoted as α, is commonly set at 0.05. This significance level indicates a 5% chance... https://www.jove.com/v/16480 73 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51216.jpg Characterization of Complex Systems Using the Design of Experiments Approach: Transient Protein Expression in Tobacco as a Case Study We describe a design of experiments approach that can be used to determine and model the influence of transgene regulatory elements, plant growth and development parameters, and incubation conditions on the transient expression of monoclonal antibodies and reporter proteins in plants. https://www.jove.com/v/51216 1224 2014-01-31T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64018.jpg An R-Based Landscape Validation of a Competing Risk Model The present protocol describes codes in R for evaluating the discrimination and calibration abilities of a competing risk model, as well as codes for the internal and external validation of it. https://www.jove.com/v/64018 337 2022-09-16T20:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68888.jpg Simulation of a Scaled Assembly Process with Collaboration of a Robotic Arm and Monitoring through a Vision System for Quality Control Here, we present a protocol for the simulation and monitoring of a scaled semi-automated assembly process, through the collaboration of a collaborative robot and verification via a computer vision system for quality control. https://www.jove.com/v/68888 347 2025-08-29T21:45:00+00:00 JoVE no https://visualize.jove.com/8791334-knowledge-based-systems-artificial-neural-networks-and-pattern-recognition-applications-to-biotechnological-processes monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11525.jpg Protein Networks An organism can have thousands of different proteins, and these proteins must cooperate to ensure the health of an organism. Proteins bind to other proteins and form complexes to carry out their functions. Many proteins interact with multiple other proteins creating a complex network of protein interactions. These interactions can be represented through maps depicting protein-protein interaction networks, represented as nodes and edges. Nodes are circles that are representative of a protein,... https://www.jove.com/v/12507 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17779.jpg Parallel Processing The brain processes sensory information rapidly due to parallel processing, which involves sending data across multiple neural pathways at the same time. This method allows the brain to manage various sensory qualities, such as shapes, colors, movements, and locations, all concurrently. For instance, when observing a forest landscape, the brain simultaneously processes the movement of leaves, the shapes of trees, the depth between them, and the various shades of green. This enables a quick and... https://www.jove.com/v/17779 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62250.jpg A Virtual Machine Platform for Non-Computer Professionals for Using Deep Learning to Classify Biological Sequences of Metagenomic Data This tutorial describes a simple method to construct a deep learning algorithm for performing 2-class sequence classification of metagenomic data. https://www.jove.com/v/62250 574 2021-09-25T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65557.jpg Superior Auto-Identification of Trypanosome Parasites by Using a Hybrid Deep-Learning Model Worldwide medical blood parasites were automatically screened using simple steps on a low-code AI platform. The prospective diagnosis of blood films was improved by using an object detection and classification method in a hybrid deep learning model. The collaboration of active monitoring and well-trained models helps to identify hotspots of trypanosome transmission. https://www.jove.com/v/65557 500 2023-10-27T20:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68270.jpg Introduction of an Integrated Pathology Image Management, Artificial Intelligence, and Reporting System Integrated image management, artificial intelligence (AI), and reporting systems have revolutionized diagnostic pathology practice. In this paper, we introduce FlexLIS, a state-of-the-art system that enables AI to assist pathologists in performing histopathology image assessments and generating diagnostic reports. https://www.jove.com/v/68270 333 2025-07-11T22:40:00+00:00 JoVE no https://visualize.jove.com/8797161-regional-and-ultrastructural-distribution-of-the-alpha-8-integrin-subunit-in-developing-and-adult-rat-brain-suggests-a-role-in-synaptic-function monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2021.jpg Preparation of Mouse Brain Tissue for Immunoelectron Microscopy We describe a protocol for transcardiac perfusion of mice, removal and sectioning of the brain, as well as immunoperoxidase staining, resin embedding, and ultrathin sectioning of the brain sections. Upon completion of these procedures, the immunostained material is ready for examination with transmission electron microscopy. https://www.jove.com/v/2021 527 2010-07-21T00:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55661.jpg Brain Membrane Fractionation: An Ex Vivo Approach to Assess Subsynaptic Protein Localization Here, we present a brain membrane fractionation protocol that represents a robust procedure to isolate proteins belonging to different synaptic compartments. https://www.jove.com/v/55661 589 2017-05-12T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56547.jpg Use of Synaptic Zinc Histochemistry to Reveal Different Regions and Laminae in the Developing and Adult Brain We describe a histochemical procedure that reveals characteristic laminar and areal zinc staining patterns in different brain regions. The zinc-staining pattern may be used in conjunction with other anatomical markers to reliably distinguish layers and regions in the developing and adult brain. https://www.jove.com/v/56547 590 2017-10-29T20:00:00+00:00 JoVE no https://visualize.jove.com/8834335-comparison-of-an-expert-system-with-other-clinical-scores-for-the-evaluation-of-severity-of-asthma monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16357.jpg Chronic Obstructive Pulmonary Disease-IV: Assessement and Diagnostic Studies Assessing and diagnosing Chronic Obstructive Pulmonary Disease (COPD) involves a detailed approach that includes a comprehensive review of medical history, physical examination, and a variety of diagnostic tests. This thorough evaluation is essential to ensure an accurate diagnosis and guide effective management strategies. Medical History • Symptom Review: Chronic symptoms such as persistent cough, sputum production, shortness of breath (dyspnea), and episodes of exacerbation are critical... https://www.jove.com/v/16357 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16360.jpg Asthma-I: Introduction Asthma is a chronic respiratory ailment that requires careful management due to its varying symptoms and influencing factors. It is characterized by airway inflammation, bronchial hyperresponsiveness, and reversible airflow obstruction, leading to symptoms like wheezing, shortness of breath, chest tightness, and coughing. The symptom frequency and intensity may vary considerably over time. It is also linked to immune system responses to allergens and irritants, highlighting the complex... https://www.jove.com/v/16360 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16361.jpg Asthma-II: Pathophysiology and Classification Asthma is a prevalent chronic respiratory condition marked by inflammation and hyperresponsiveness of the airways. Its pathophysiology involves complex interactions among inflammatory pathways, immune responses, and neural mechanisms. Additionally, environmental and genetic factors play crucial roles in determining an individual's susceptibility to asthma and the severity of their condition. Critical processes in asthma pathophysiology include: Initiation of Airway Inflammation: Trigger... https://www.jove.com/v/16361 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16362.jpg Asthma-III: Symptoms and Complications Asthma, a common chronic respiratory condition, is classified considering the frequency and severity of symptoms alongside lung function impairment. Understanding this classification is essential for appropriate treatment and management. Here's a detailed look at the classification of asthma and its clinical features and complications: Classification of Asthma Intermittent Asthma: Symptoms occur fewer than twice a week. Night-time awakenings due to asthma occur fewer than twice a month.<br... https://www.jove.com/v/16362 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16363.jpg Asthma-IV: Diagnostic and Management The diagnosis and management of asthma are comprehensive, encompassing clinical assessments, lung function tests, and pharmacological interventions. Here's an overview: Clinical Assessment for Asthma: This is the first step in diagnosing and managing asthma. It includes: Detailed Medical History: This includes asking about symptoms such as wheezing, coughing, chest tightness, and breathlessness. Information about triggers like exercise, allergens, or cold air is crucial. Physical... https://www.jove.com/v/16363 90 JoVE no https://cloudfront.jove.com/files/ftp_upload/40977/40977_article_thumb_40977.jpg Asthma III: Clinical Manifestations Asthma presents with a characteristic pattern of episodic respiratory symptoms that reflect underlying airway inflammation, bronchoconstriction, and mucus hypersecretion. Although severity varies among individuals, certain clinical manifestations are considered hallmarks of the disorder and often guide diagnosis and assessment.Respiratory SymptomsA persistent cough is one of the most common early features of asthma. It is frequently dry and tends to worsen at night or in the early morning,... https://www.jove.com/v/40977 73 2026-05-14T20:02:37+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64801.jpg Symptom Assessment of Patients with Allergic Rhinitis Using an Allergen Exposure Chamber A protocol for conducting a challenge in an allergen exposure chamber (AEC) facility is presented. AECs have proven to be safe and effective tools for the induction of allergic symptoms or as an endpoint in the efficacy testing of allergen immunotherapy due to their ability to maintain stable particle concentrations and environmental conditions. https://www.jove.com/v/64801 527 2023-03-03T22:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66065.jpg Measuring Psoriasis Severity at Home This paper details the creation of a Psoriasis Thickness Reference Card, enabling psoriasis patients to self-assess their psoriasis plaque thickness without the need for physician assistance. Additionally, the precision of self-assessment for psoriasis redness and scaliness by employing reference images depicting various skin tones is assessed. https://www.jove.com/v/66065 148 2024-03-01T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67742.jpg Asthma Detection Research Based on Voice Signal Processing and Machine Learning This study employed voice signal analysis and machine learning methods, utilizing MATLAB to extract distinctive voice features for non-invasive early detection of asthma. The Support Vector Machine (SVM) and Random Forest (RF) algorithms demonstrated comparable performance in terms of overall classification accuracy, although SVM may achieve a better balance between sensitivity and specificity. https://www.jove.com/v/67742 244 2025-07-22T19:40:00+00:00 JoVE no https://visualize.jove.com/8866051-self-organization-in-computer-simulated-selective-systems monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13681.jpg Cyclic Processes And Isolated Systems A thermodynamic system with zero heat exchange and work is an isolated system. For these systems, the internal energy remains constant. In the case of a non-isolated system, the change in the internal energy is zero only if the process is cyclic. A thermodynamic process is considered cyclic if the system undergoes a series of changes and returns to its initial state. Consider a cyclic process that returns to its initial state, undergoing a four-step process. The heat transfer along each path... https://www.jove.com/v/13681 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16029.jpg Signal and System A signal x(t) is a set of data or a time function representing a variable of interest. Signals typically convey information about a phenomenon, such as atmospheric temperature, humidity, human voice, television images, a dog's bark, or birdsongs. More generally, a signal can be a function of more than one independent variable. For instance, images depend on horizontal and vertical positions and can be regarded as two-dimensional signals. However, this text will focus on one-dimensional signals... https://www.jove.com/v/16029 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16031.jpg Control Systems Control systems are everywhere in contemporary society, influencing diverse applications from aerospace to automated manufacturing. These systems can be found naturally within biological processes, such as blood sugar regulation and heart rate adjustment in response to stress, as well as in man-made systems like elevators and automated vehicles. A control system is essentially a network of subsystems and processes that collaboratively convert specific inputs into desired outputs. At the heart... https://www.jove.com/v/16031 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16045.jpg Classification of Systems-I Linearity is a system property characterized by a direct input-output relationship, combining homogeneity and additivity. Homogeneity dictates that if an input x(t) is multiplied by a constant c, the output y(t) is multiplied by the same constant. Mathematically, this is expressed as: Additivity means that the response to the sum of multiple inputs is the sum of their individual responses. For inputs x1(t) and x2(t) producing outputs y1(t) and y2(t), respectively: Combining homogeneity and... https://www.jove.com/v/16045 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16094.jpg Feedback control systems Feedback control systems are categorized in various ways based on their design, analysis, and signal types. Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity... https://www.jove.com/v/16094 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18143.jpg Introduction to Cognitive Psychology Cognitive psychology is the field of psychology dedicated to examining how people think. It attempts to explain how and why we think the way we do by studying the interactions among human thinking, emotion, creativity, language, and problem-solving, as well as other cognitive processes. Cognitive psychology studies how information is processed and manipulated in remembering, thinking, and knowing. This field emerged in the mid-20th century, following a period dominated by behaviorism, which... https://www.jove.com/v/18143 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50519.jpg Designing and Implementing Nervous System Simulations on LEGO Robots An approach to neural network modeling on the LEGO Mindstorms robotics platform is presented. The method provides a simulation tool for invertebrate neuroscience research in both the research lab and the classroom. This technique enables the investigation of biomimetic robot control principles. https://www.jove.com/v/50519 634 2013-05-25T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51047.jpg Automated, Quantitative Cognitive/Behavioral Screening of Mice: For Genetics, Pharmacology, Animal Cognition and Undergraduate Instruction Fully automated system for measuring physiologically meaningful properties of the mechanisms mediating spatial localization, temporal localization, duration, rate and probability estimation, risk assessment, impulsivity, and the accuracy and precision of memory, in order to assess the effects of genetic and pharmacological manipulations on foundational mechanisms of cognition in mice. https://www.jove.com/v/51047 983 2014-02-27T06:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63342.jpg Interactive and Visualized Online Experimentation System for Engineering Education and Research This work describes an online experimentation system that provides visualized experiments, including the visualization of theories, concepts, and formulas, visualizing the experimental process with three-dimensional (3-D) virtual test rigs, and visualizing the control and monitoring system using widgets such as charts and cameras. https://www.jove.com/v/63342 515 2021-11-24T22:00:00+00:00 JoVE no https://visualize.jove.com/8876142-alphavirus-based-expression-vectors-strategies-and-applications monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/50830.jpg Rescue of Recombinant Newcastle Disease Virus from cDNA Newcastle disease virus (NDV) has been extensively studied in the last few years in order to develop new vectors for vaccination and therapy, among others. These studies have been possible due to techniques to rescue recombinant virus from cDNA, such as those we describe here. https://www.jove.com/v/50830 655 2013-10-12T06:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58960.jpg Production, Purification, and Quality Control for Adeno-associated Virus-based Vectors Here, we describe an efficient and reproducible strategy to produce, titer, and quality-control batches of adeno-associated virus vectors. It allows the user to obtain a vector preparation with high-titer (≥1 x 1013 vector genomes/mL) and a high purity, ready for in vitro or in vivo use. https://www.jove.com/v/58960 561 2019-01-29T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65572.jpg Transgene Expression in Cultured Cells Using Unpurified Recombinant Adeno-Associated Viral Vectors Recombinant adeno-associated virus (rAAV) is widely used for clinical and preclinical gene delivery. An underappreciated use for rAAVs is the robust transduction of cultured cells without the need for purification. For researchers new to rAAV, we provide a protocol for transgene cassette cloning, crude vector production, and cell culture transduction. https://www.jove.com/v/65572 401 2023-10-20T21:20:00+00:00 JoVE no https://visualize.jove.com/8894590-the-anxiolytics-ci-988-and-chlordiazepoxide-fail-to-reduce-immediate-early-gene-mrna-stimulation-following-exposure-to-the-rat-elevated-x-maze monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2705.jpg The Successive Alleys Test of Anxiety in Mice and Rats The plus-maze measures anxiety-like behaviour in rodents. There are two opposite closed and two opposite open arms; anxious rodents avoid the open arms. The central area is neither completely open nor closed, so time spent here is ambiguous and difficult to interpret. Here a modification of the plus-maze protocol eliminating this area is described. https://www.jove.com/v/2705 305 2013-06-17T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56428.jpg Testing Animal Anxiety in Rats: Effects of Open Arm Ledges and Closed Arm Wall Transparency in Elevated Plus Maze Test Rats' anxiety-like behavior tested by the elevated plus maze varies highly depending on the testing environment. Here we show how apparatus settings, especially arm structure, affect behavior on the maze, and we explain a reliable protocol to detect effects of anxiolytic drugs. This report will contribute to anxiety research. https://www.jove.com/v/56428 474 2018-06-29T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58184.jpg The Unpredictable Chronic Mild Stress Protocol for Inducing Anhedonia in Mice Here we present the unpredictable chronic mild stress protocol in mice. This protocol induces a long-term depressive-like phenotype and enables to assess the efficacy of putative antidepressants in reversing the behavioral and neuromolecular depressive-like deficits. https://www.jove.com/v/58184 433 2018-10-24T20:30:00+00:00 JoVE no https://visualize.jove.com/8931858-the-ossification-centre-of-the-talus monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14015.jpg Bone Formation by Intramembranous Ossification Intramembranous ossification is one of the two processes involved in the development of bones within an embryo. The flat bones of the face, most of the cranial bones, and the clavicles are formed via this process. During intramembranous ossification, the bones develop directly from sheets of undifferentiated mesenchymal connective tissue. The process begins when mesenchymal cells in the embryonic skeleton gather together and differentiate into osteogenic cells, which then develop into... https://www.jove.com/v/14015 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14054.jpg Bones of the Lower Limb: Tibia and Fibula The tibia is the main weight-bearing bone of the lower leg. It is larger than the fibula with which it is paired. The tibia is also the second longest bone in the body and is located right below the skin. The proximal end of the tibia forms the medial and the lateral condyle, which articulates with the condyles of the femur to form the knee joint. Between the articulating surfaces is the irregular elevated area known as the intercondylar eminence that serves as the inferior attachment point for... https://www.jove.com/v/14054 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14057.jpg Changes in the Appendicular Skeleton with Age The upper and lower limb initially develops as a small bulge called a limb bud, which appears on the lateral side of the early embryo. The upper limb bud appears near the end of the fourth week of development, with the lower limb bud appearing shortly after. Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying... https://www.jove.com/v/14057 69 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14075.jpg Ankle Joint The ankle is formed by the talocrural joint (crural = leg). It consists of the articulations between the talus bone of the foot and the distal ends of the tibia and fibula of the leg. The superior aspect of the talus bone is square-shaped and has three areas of articulation. The top of the talus articulates with the inferior tibia. This is the portion of the ankle joint that carries the body weight between the leg and foot. The sides of the talus are firmly held in position by the articulations... https://www.jove.com/v/14075 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14076.jpg Development of the Limb Synovial Joints Joints form during embryonic development in conjunction with the formation and growth of the associated bones. The embryonic tissue that gives rise to all bones, cartilage, and connective tissues of the body is called mesenchyme. The mesenchymal stem cells differentiate into chondrocytes that form the hyaline cartilage, and later the cartilaginous model of the bone. This model further transforms into a bone. This process is known as endochondral ossification. During development, the limbs... https://www.jove.com/v/14076 67 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14685.jpg Bone Formation by Endochondral Ossification Bone formation, or ossification, begins around the sixth to seventh week of embryonic development. Most bones develop from a cartilaginous template through the process of endochondral ossification. Cartilage formation begins when clusters of mesenchymal cells differentiate into chondrocytes. These chondrocytes proliferate rapidly and secrete an extracellular matrix that becomes encased in a membrane called the perichondrium. The resulting cartilage model provides a template that resembles the... https://www.jove.com/v/14685 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54978.jpg Culture of Murine Embryonic Metatarsals: A Physiological Model of Endochondral Ossification We present a protocol to dissect and culture embryonic day 15 (E15) murine metatarsal bones. This highly physiological ex vivo model of endochondral ossification provides conditions closer to the in vivo situation than cells in monolayer or 3D culture and is a vital tool for investigating bone growth and development. https://www.jove.com/v/54978 443 2016-12-03T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56395.jpg Autologous Microfractured and Purified Adipose Tissue for Arthroscopic Management of Osteochondral Lesions of the Talus The aim of this study is to report a protocol for the arthroscopic treatment of osteochondral lesions of the talus using microfractured and purified adipose-derived stem cells. https://www.jove.com/v/56395 444 2018-01-23T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56396.jpg Treatment of Ankle Osteoarthritis with Total Ankle Replacement Through a Lateral Transfibular Approach We present our preoperative, operative, and postoperative protocols for the treatment of osteoarthritis of the ankle with total ankle replacement via lateral transfibular approach. https://www.jove.com/v/56396 541 2018-01-24T22:00:00+00:00 JoVE no https://visualize.jove.com/8944880-an-audit-of-the-cochlear-implant-service-in-manchester monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/63153.jpg Performing Intracochlear Electrocochleography During Cochlear Implantation Electrocochleography (ECochG) measures inner ear potentials generated in response to acoustic stimulation. In cochlear implant (CI) candidates, such inner ear potentials can be measured directly with the implant electrodes. In this video, we systematically explain how to perform ECochG recordings during CI surgery. https://www.jove.com/v/63153 550 2022-03-08T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64047.jpg Robotic Cochlear Implantation for Direct Cochlear Access Robotic cochlear implantation is a procedure for minimally invasive inner ear access. Compared to conventional surgery, robotic cochlear implantation involves additional steps that need to be carried out in the operating room. In this article we give a description of the procedure and highlight the important aspects of robotic cochlear implantation. https://www.jove.com/v/64047 486 2022-06-16T21:05:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64552.jpg Systematic Hearing Performance Evaluation Process for Adolescents with Cochlear Implantation at Early Ages This paper describes a battery of tests used to clinically assess the hearing performance of adolescent, Mandarin-speaking, experienced cochlear implant users upgraded to a new fine structure coding strategy. The battery of tests include speech in quiet conditions, speech in noisy conditions, lexical tone, and music perception. https://www.jove.com/v/64552 364 2023-03-24T21:10:00+00:00 JoVE no https://visualize.jove.com/8963379-evaluation-of-automatic-knowledge-acquisition-techniques-in-the-diagnosis-of-acute-abdominal-pain-acute-abdominal-pain-study-group monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16403.jpg Assessment of the Abdomen III: Palpation Palpation is a crucial tactile examination method for assessing abdominal organs and detecting conditions like tenderness, distention, masses, or fluid. It involves both light and deep palpation techniques, each serving specific diagnostic purposes. Light palpation helps identify tenderness and other surface-level indicators, while deep palpation locates and assess abdominal masses and organ boundaries. A skilled professional can gather valuable insights through palpation, including evaluating... https://www.jove.com/v/16403 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16429.jpg Peptic Ulcer Disease III: Clinical Manifestations and Diagnostic Studies Peptic ulcer disease (PUD) presents with diverse symptoms depending on the location and severity of the ulcer. Clinical manifestations of peptic ulcer include dull pain and a burning sensation in the mid-epigastric region. Few clinical manifestations differentiate gastric ulcers from duodenal ulcers. Distinctions in the location, timing, and pain relief are crucial for healthcare providers in differentiating between gastric and duodenal ulcers during clinical assessments. Location of Pain:... https://www.jove.com/v/16429 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16435.jpg Acute Pancreatitis II: Clinical Manifestations and Management Acute pancreatitis presents a complex medical emergency characterized by rapid onset inflammation of the pancreas, demanding timely diagnosis and management to prevent complications. The condition primarily manifests through severe upper abdominal pain that often radiates to the back. This pain intensifies following the consumption of fatty foods. Accompanying symptoms such as nausea, vomiting, abdominal distention, fever, dyspnea, cyanosis, and jaundice can vary in intensity but significantly... https://www.jove.com/v/16435 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16438.jpg Appendicitis-I: Introduction The appendix, a small, narrow, blind tube extending from the inferior part of the cecum, is widely regarded as a vestigial organ, having lost much of its original function through evolution. Despite its diminished role, the appendix can become inflamed, a condition known as appendicitis. Etiology: Appendicitis can arise from various causes, primarily rooted in the obstruction of the appendix lumen. Factors contributing to this obstruction include fecal accumulation, lymphoid hyperplasia and, in... https://www.jove.com/v/16438 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16439.jpg Appendicitis-II: Diagnostic Studies and Management Diagnosing and managing appendicitis requires a structured and comprehensive approach that spans from initial assessment to postoperative care. Here is an overview of the process: Diagnosing Appendicitis It requires a multifaceted approach, starting with a detailed physical examination to pinpoint the location and nature of the pain and identify any associated symptoms. Laboratory tests play a crucial role. A complete Blood Count (CBC) typically reveals leukocytosis (an increased number of... https://www.jove.com/v/16439 89 JoVE no https://cloudfront.jove.com/files/ftp_upload/18466/18466_article_thumb_18466.jpg Acute Pyelonephritis II: Diagnostic Studies and Management Introduction:For diagnosing acute pyelonephritis, a comprehensive patient history is collected to identify symptoms such as dysuria, frequent or urgent urination, flank pain, or costovertebral angle (CVA) tenderness that may suggest a kidney infection.Physical ExaminationDuring the physical examination, CVA tenderness is assessed. This involves gentle percussion over the costovertebral angle, where tenderness often indicates a kidney infection.Diagnostic TestsUrinalysis: Used to identify white... https://www.jove.com/v/18466 88 2025-08-11T17:03:03+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65095.jpg Multimodality Diagnosis of Mesenteric Ischemia This article presents a multimodal approach that aims to overcome the limitations of traditional methods in detecting mesenteric ischemia and preventing bowel necrosis. The presented technique offers a promising solution by combining state-of-the-art ultrasonography with cutting-edge near-infrared light technologies. https://www.jove.com/v/65095 307 2023-07-21T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65487.jpg An Approach to Point-Of-Care Ultrasound Evaluation of the Abdominal Aorta This protocol reviews the steps to image the abdominal aorta with point-of-care ultrasound. We discuss image acquisition, troubleshooting imaging pitfalls and artifacts, and the recognition of life-threatening abdominal aortic pathology. https://www.jove.com/v/65487 432 2023-09-08T20:40:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66587.jpg Clinical Effects of Ultrasound-Guided Acupotomy in Knee Osteoarthritis Treatment This paper introduces the operation method of ultrasound-guided acupotomy for knee osteoarthritis, which can reduce synovial thickness and improve knee joint function. It has the advantages of precise target, low treatment risk, few complications, and high safety. https://www.jove.com/v/66587 297 2024-04-26T21:20:00+00:00 JoVE no https://visualize.jove.com/8990162-folding-of-the-n-terminal-ligand-binding-region-of-integrin-alpha-subunits-into-a-beta-propeller-domain monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2721.jpg Transmembrane Domain Oligomerization Propensity determined by ToxR Assay An efficient procedure to assess the oligomerization propensity of single-pass transmembrane domains (TMDs) is described. Chimeric proteins consisting of the TMD fused to ToxR are expressed in an E. coli reporter strain. TMD-induced oligomerization causes dimerization of ToxR, activation of transcription and production of the reporter protein, -galactosidase. https://www.jove.com/v/2721 405 2011-05-26T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12253.jpg Mechanism of Filopodia Formation Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles. Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication... https://www.jove.com/v/12253 99 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12255.jpg Mechanism of Lamellipodia Formation Cells migrating in response to external stimuli form lamellipodia, which are thin membrane protrusions supported by a mesh of linked, branched, or unbranched actin filaments. These actin filaments interact with myosin motor proteins, creating the dynamic actomyosin complex within the cytoskeleton. Contractility, or the ability to generate contractile stress, is inherent to the actomyosin complex. It helps cells detect the stiffness of the surrounding ECM and exert contractile force for... https://www.jove.com/v/12255 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13341.jpg Fibronectins Connect Cells with ECM Fibronectin is an adhesive glycoprotein present in the extracellular matrix of embryogenic and adult tissue. These molecules primarily aid in regulating cell motility and attachment. A fibronectin molecule is composed of two identical polypeptide chains attached to each other by a pair of disulfide bonds at the C-terminal. Both proteoglycans and collagen are attached to fibronectin proteins, which, in turn, are attached to integrin proteins. These integrin proteins interact with transmembrane... https://www.jove.com/v/13341 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13348.jpg Integrins Animal and protozoan cells do not have cell walls to help maintain shape and provide structural stability. Instead, these eukaryotic cells secrete a sticky mass of carbohydrates and proteins into the spaces between adjacent cells. This network of proteins and molecules is called an extracellular matrix or ECM. Some ECM proteins assemble into a basement membrane to which the remaining components adhere. Proteoglycans typically form the bulk of the ECM while fibrous proteins, like collagen,... https://www.jove.com/v/13348 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13349.jpg Activation of Integrins Integrins bind ligands and transmit information from outside the cell to inside or vice-versa through an "outside-in signaling" or "inside-out signaling." In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding events provide an effective stimulus. https://www.jove.com/v/13349 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13350.jpg Intracellular Signaling Affects Focal Adhesions Integrins act both as extracellular input receivers and as intracellular processing activators. As their name suggests, integrins are entirely integrated into the membrane structure. Their hydrophobic membrane-spanning regions interact with the phospholipid bilayer's hydrophobic region. These membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors. They activate intracellular response cascades when their effectors are bound and active. Some... https://www.jove.com/v/13350 77 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51206.jpg Efficient Production and Purification of Recombinant Murine Kindlin-3 from Insect Cells for Biophysical Studies Kindlins are fundamental to cell adhesion through integrins but studies of them have been hampered by the difficulty encountered in expressing them recombinantly in bacterial hosts. We describe here methods for their efficient production in baculovirus-infected insect cells. https://www.jove.com/v/51206 832 2014-03-19T21:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64401.jpg A Flow Cytometry-Based High-Throughput Technique for Screening Integrin-Inhibitory Drugs This protocol describes a flow cytometry-based, high-throughput screening method to identify small-molecule drugs that inhibit β2 integrin activation on human neutrophils. https://www.jove.com/v/64401 255 2024-02-02T20:00:00+00:00 JoVE no https://visualize.jove.com/8991458-identification-of-the-nonlinear-state-space-dynamics-of-the-action-perception-cycle-for-visually-induced-postural-sway monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14935.jpg Major Somatic Sensory Pathways Sensory impulses related to touch, pressure, vibration, and proprioception from various body parts, such as the limbs, trunk, neck, and posterior head, travel to the cerebral cortex through the posterior column-medial lemniscus pathway. The pathway’s name derives from the two white-matter tracts that convey the impulses: the spinal cord's posterior column and the brainstem's medial lemniscus. First-order sensory neurons extend their axons into the spinal cord, forming the posterior columns... https://www.jove.com/v/14935 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16103.jpg Linear Approximation in Time Domain Nonlinear systems often require sophisticated approaches for accurate modeling and analysis, with state-space representation being particularly effective. This method is especially useful for systems where variables and parameters vary with time or operating conditions, such as in a simple pendulum or a translational mechanical system with nonlinear springs. For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length, the... https://www.jove.com/v/16103 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51077.jpg Computerized Dynamic Posturography for Postural Control Assessment in Patients with Intermittent Claudication Individuals with intermittent claudication exhibit poor balance compared to healthy controls. Computerized dynamic posturography is an objective method for measuring an individual's postural responses to balance disturbances. This provides an objective reflection of the person’s ability to respond to situations under which sensory stimuli are altered and unexpected perturbations occur. https://www.jove.com/v/51077 892 2013-12-11T22:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59309.jpg An Instrumented Pull Test to Characterize Postural Responses Impairment of postural reflexes, termed postural instability, is difficult to quantify. Clinical assessments such as the pull test suffer issues with reliability and scaling. Here, we present an instrumented version of the pull test to objectively characterize postural responses. https://www.jove.com/v/59309 738 2019-04-06T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60078.jpg Experimental Methods to Study Human Postural Control This article presents an experimental/analytic framework to study human postural control. The protocol provides step-by-step procedures for performing standing experiments, measuring body kinematics and kinetics signals, and analyzing the results to provide insight into the mechanisms underlying human postural control. https://www.jove.com/v/60078 492 2019-09-11T22:00:00+00:00 JoVE no https://visualize.jove.com/9027329-acth-and-aii-differentially-stimulate-steroid-hormone-orphan-receptor-mrnas-in-adrenal-cortical-cells monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3059.jpg Biochemical Reconstitution of Steroid Receptor•Hsp90 Protein Complexes and Reactivation of Ligand Binding An in vitro method for preparing functional glucocorticoid receptor (GR)•hsp90 protein complexes from purified proteins and cellular lysates is described. The method utilizes immunoadsorption of recombinant GR followed by salt-stripping and protein complex reconstitution. The importance of cofactors and buffer conditions are discussed, as are potential method applications. https://www.jove.com/v/3059 667 2011-09-21T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10879.jpg Hypothalamic-Pituitary Axis The response to stress—be it physical or psychological, acute or chronic—involves activation of the Hypothalamic-Pituitary-Adrenal (HPA) axis. The HPA axis is part of the neuroendocrine system because it involves both neuronal and hormonal communication. Its function is to regulate homeostatic systems—metabolic, cardiovascular, and immune—providing the necessary means to respond to a stressor. What Happens During Stress In response to stress, the neurons in the hypothalamus release... https://www.jove.com/v/10879 97 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14466.jpg Adrenergic Receptors: ɑ Subtype Adrenoceptors are classified into α and ꞵ classes based on their potencies to catecholamine agonists. α-adrenoceptors show the following order of catecholamine potency: Adrenaline ≥ Noradrenaline >> Isoprenaline α-adrenoceptors are further divided into α1 and α2-adrenoceptors. α1-Adrenoceptors: These receptors are located postsynaptically on the effector organs and cause constriction of smooth muscle mediated by activation of phospholipase C—inositol-1,4,5-trisphosphate... https://www.jove.com/v/14466 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14467.jpg Adrenergic Receptors: β Subtype β-adrenoceptors have varied sensitivities towards adrenaline, noradrenaline, and isoprenaline. The order of agonist potency is as follows: Isoprenaline > Adrenaline > Noradrenaline Neurotransmitter binding to these receptors causes activation of adenylyl cyclase resulting in increased concentrations of cAMP and modulation of calcium ion channels within the cell. They are further classified into β1, β2, and β3 subtypes. β1-adrenoceptors: β1-adrenoceptors have equal affinities for... https://www.jove.com/v/14467 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14987.jpg Hormones of the Adrenal Glands Adrenal hormones play a pivotal role in maintaining the body's electrolyte balance and orchestrating responses to stress, showcasing the intricate functions of the adrenal cortex and medulla. The adrenal cortex, a powerhouse of hormone synthesis, generates over two dozen corticosteroid hormones. The zona glomerulosa produces mineralocorticoids, exemplified by aldosterone, influencing the electrolyte composition of body fluids. The synthesis of glucocorticoids such as cortisol and corticosterone... https://www.jove.com/v/14987 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14988.jpg Adrenal Gland Disorders Adrenal gland disorders manifest when the production of adrenal hormones deviates from the norm, resulting in either excessive or insufficient concentrations. Adrenal insufficiency, characterized by insufficient cortisol and aldosterone production, leads to conditions like Addison's disease. This disorder, affecting the adrenal cortex, exhibits symptoms such as skin bronzing, dehydration, low blood pressure, fatigue, and weight loss. Congenital adrenal hyperplasia, a genetic ailment causing... https://www.jove.com/v/14988 87 JoVE no https://cloudfront.jove.com/files/ftp_upload/40896/40896_article_thumb_40896.jpg Cushing Syndrome II: Pathophysiology Cortisol production is normally governed by the hypothalamic–pituitary–adrenal (HPA) axis, which maintains hormonal balance through tightly regulated feedback mechanisms. Disruption of this regulatory system is central to the development of Cushing syndrome, whether the excess cortisol originates from external medications or internal pathology. Persistent cortisol elevation alters metabolism, immune function, and endocrine signaling, producing the characteristic clinical features of the... https://www.jove.com/v/40896 79 2026-04-13T21:37:37+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58530.jpg Isolation, Fixation, and Immunofluorescence Imaging of Mouse Adrenal Glands Here we present a method to isolate adrenal glands from mice, fix the tissues, section them, and perform immunofluorescence staining. https://www.jove.com/v/58530 517 2018-10-02T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59016.jpg Primary Culture of Rat Adrenocortical Cells and Assays of Steroidogenic Functions The hormone secreted by the adrenal cortex is vital for animals against stress and diseases. Here, we present a protocol to culture the primary rat adrenal cells. It could be a good in vitro platform for investigating the mechanisms of the reagent of interest in adrenal steroidogenesis and lipid biosynthesis. https://www.jove.com/v/59016 273 2019-03-12T19:30:00+00:00 JoVE no https://visualize.jove.com/9036972-aml1a-and-aml1b-can-transactivate-the-human-il-3-promoter monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/57033.jpg Proliferation and Differentiation of Murine Myeloid Precursor 32D/G-CSF-R Cells Here detailed protocols for culturing the murine myeloid precursor 32D/G-CSF-R cell line, performing viral infections, and carrying out proliferation and differentiation assays are presented. This cell line is suitable for studying myeloid cell development, and the role of genes of interest in myeloid cell growth and neutrophilic differentiation. https://www.jove.com/v/57033 621 2018-02-21T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64834.jpg Intra-Peritoneal Transplantation for Generating Acute Myeloid Leukemia in Mice Here, intra-peritoneal injection of leukemia cells is utilized to establish and propagate acute myeloid leukemia (AML) in mice. This new method is effective in the serial transplantation of AML cells and can serve as an alternative for those who may experience difficulties and inconsistencies with intravenous injection in mice. https://www.jove.com/v/64834 602 2023-01-06T22:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68244.jpg Intracellular Phosphoflow Cytometry of Acute Myeloid Leukemia Patient-Derived Xenotransplants Here, a phosphoflow cytometry-based method is described to analyze signaling downstream of the mTORC1, JAK/STAT5, and MAPK pathways in acute human myeloid leukemia cells xenografted into mice and obtained from bone marrow aspirates. p-STAT5, p-4EBP1, p-RPS6, and p-ERK1/2 levels are simultaneously measured using a next-generation spectral flow cytometer with high sensitivity. https://www.jove.com/v/68244 458 2025-06-06T22:35:00+00:00 JoVE no https://visualize.jove.com/9054759-automatic-arrhythmia-identification-using-analysis-of-the-atrioventricular-association-application-to-a-new-generation-of-implantable-defibrillators-participating-centers-of-the-automatic-recognition-of-arrhythmia-study-group monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3750.jpg A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation Dual-chamber implantable cardioverter-defibrillators (ICDs) may improve detection of atrial fibrillation as well as differentiation of tachycardias. However, this advantage is undermined by complications associated with the second electrode, which is required in conventional dual chamber devices. Therefore, BIOTRONIK has developed a new electrode called the LinoxSMART S DX that, when used in conjunction with the Lumax DX ICD, offers dual-chamber detection without the risks associated with the... https://www.jove.com/v/3750 1000 2012-02-28T22:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15028.jpg Mechanism of Cardiac Arrhythmias Arrhythmias are irregular heart rhythms occurring when the heart's electrical impulses become abnormal. These disturbances can lead to various symptoms, depending on their severity and the underlying cause. Some common factors contributing to arrhythmias include hypoxia, ischemia, electrolyte imbalances, excessive catecholamine exposure, drug toxicity, and muscle overstretching. Arrhythmias can be classified into two main types based on the rate and site of origin of abnormal heart rhythms. https://www.jove.com/v/15028 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15276.jpg Disturbances in Heart Rhythm Arrhythmia or dysrhythmia refers to an abnormal heart rhythm caused by a defect in the heart's conduction system. It can cause the heart to beat irregularly, too quickly, or too slowly, leading to symptoms like chest pain, shortness of breath, and fainting. Factors such as stress, caffeine, alcohol, nicotine, cocaine, certain drugs, congenital defects, diseases, and electrolyte abnormalities can trigger arrhythmias. Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart... https://www.jove.com/v/15276 89 2025-07-29T16:29:05+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17939/17939_article_thumb_17939.jpg Dysrhythmias II: Classification of Tachyarrhythmias Tachyarrhythmias are a type of dysrhythmia where the heart rate exceeds 100 beats per minute. Here are some common types of tachyarrhythmias:Sinus TachycardiaSinus tachycardia originates from increased impulses from the sinus node, leading to an elevated heart rate. It is often triggered by stress, fever, or exercise.Patients may experience palpitations, a sensation of a racing heart, dizziness, and chest discomfort.Causes and Risk Factors: Common causes include physical exertion, emotional... https://www.jove.com/v/17939 88 2025-06-19T16:35:48+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17942/17942_article_thumb_17942.jpg Dysrhythmias V: Evaluating Dysrhythmias Dysrhythmias, also known as arrhythmias, are disturbances in the heart's rhythm that range from benign to life-threatening. A thorough evaluation is crucial for appropriate management and involves a comprehensive medical history, physical examination, and various diagnostic tests.Medical HistorySymptoms: Collect detailed information on palpitations, dizziness, syncope, chest pain, and fatigue. Note their onset, frequency, and triggers.Previous Cardiac Issues: Document any history of heart... https://www.jove.com/v/17942 90 2025-06-19T16:36:46+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17948/17948_article_thumb_17948.jpg Cardiopulmonary Resuscitation III: AED Use Introduction to AEDAn Automated External Defibrillator (AED) is a portable medical device that analyzes the heart's rhythm and, if necessary, delivers an electrical shock to help the heart re-establish an effective rhythm during sudden cardiac arrest (SCA). SCA occurs when the heart suddenly and unexpectedly stops beating, leading to a loss of blood flow to the brain and other vital organs. In such emergencies, time is of the essence, and using an AED, combined with Cardiopulmonary... https://www.jove.com/v/17948 83 2025-06-19T16:38:36+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18437/18437_article_thumb_18437.jpg ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias Arrhythmia is a condition characterized by an irregular heart rhythm, with ECG changes that differ based on its origin and nature. The types of arrhythmias discussed below include atrial, junctional, and ventricular arrhythmias.Atrial ArrhythmiasPremature Atrial Complexes (PACs): PACs are early atrial beats caused by stress, caffeine, alcohol, electrolyte imbalances, hypoxia, hyperthyroidism, or certain medications (e.g., bronchodilators and decongestants). The ECG shows early P waves with an... https://www.jove.com/v/18437 85 2025-06-19T16:15:27+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56478.jpg Electrophysiological Assessment of Murine Atria with High-Resolution Optical Mapping This protocol describes the electrophysiological evaluation of murine atria utilizing an optical mapping system with a high temporal and spatial resolution, including dual recordings of the membrane voltage and Ca2+ transient under programmed stimulation through a specialized electrode catheter. https://www.jove.com/v/56478 499 2018-02-22T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67001.jpg Rat Model of Right-Sided Cardiac Remodeling and Arrhythmia Using Pulmonary Artery Banding Right heart failure (RHF) is characterized by right-sided cardiac dilation and hypertrophy, leading to ventricular and atrial malfunction. Cardiopulmonary conditions associated with RHF are accompanied by an increased risk for cardiac arrhythmias. This article describes a standardized model of pulmonary artery banding-induced RHF associated with enhanced ventricular and atrial arrhythmogenesis. https://www.jove.com/v/67001 639 2024-08-30T20:20:00+00:00 JoVE no https://visualize.jove.com/9077453-nap-i-is-a-functional-homologue-of-taf-i-that-is-required-for-replication-and-transcription-of-the-adenovirus-genome-in-a-chromatin-like-structure monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11532.jpg The Nucleosome Core Particle Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins. The paradox Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA... https://www.jove.com/v/11532 130 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11579.jpg Bacterial RNA Polymerase Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity. In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize... https://www.jove.com/v/11579 43 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14371.jpg Nucleic Acid Structure The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group on the ribose's second carbon and a hydrogen on the deoxyribose's second carbon. The phosphate residue attaches to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms a 5′ to 3′ phosphodiester linkage. DNA Structure DNA has a double-helix structure. The... https://www.jove.com/v/14371 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14746.jpg The Nucleosome Core Particle Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins. Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during... https://www.jove.com/v/14746 72 JoVE no https://cloudfront.jove.com/files/ftp_upload/19476/19476_article_thumb_19476.jpg Nucleoid The nucleoid represents a structurally and functionally distinct region within prokaryotic cells, where the cell's DNA and associated proteins are housed. Unlike eukaryotic cells, prokaryotes lack a membrane-bound nucleus, and the nucleoid facilitates the organization and accessibility of the genetic material within this constraint. The DNA in most bacteria and archaea exists as a single, circular, double-stranded molecule that is highly compacted through supercoiling and interactions with... https://www.jove.com/v/19476 84 2025-06-12T16:31:54+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19590/19590_article_thumb_19590.jpg DNA Bacteriophages Bacteriophages, or phages, are viruses that specifically infect bacteria, utilizing their genetic material to hijack host cellular machinery for replication. DNA bacteriophages employ single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA) genomes. These phages exhibit diverse replication strategies and host interactions, influencing their ecological roles and applications in biotechnology and medicine.ssDNA BacteriophagesssDNA phages, with their small genomes, utilize unique strategies to... https://www.jove.com/v/19590 86 2025-06-12T16:30:01+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52474.jpg Nucleocapsid Annealing-Mediated Electrophoresis (NAME) Assay Allows the Rapid Identification of HIV-1 Nucleocapsid Inhibitors This protocol describes NAME, an assay that allows the rapid identification of molecules able to inhibit in vitro the chaperone activities of HIV-1 nucleocapsid protein. https://www.jove.com/v/52474 513 2015-01-19T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53296.jpg Isolation of Viral Replication Compartment-enriched Sub-nuclear Fractions from Adenovirus-infected Normal Human Cells We provide a novel strategy to isolate viral replication compartments (RC) from adenovirus (Ad)-infected human cells. This approach represents a cell-free system that can help to elucidate the molecular mechanisms regulating viral genome replication and expression as well as regulation of viral-host interactions established at the RC. https://www.jove.com/v/53296 622 2015-11-12T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62073.jpg DNA-Tethered RNA Polymerase for Programmable In vitro Transcription and Molecular Computation We describe the engineering of a novel DNA-tethered T7 RNA polymerase to regulate in vitro transcription reactions. We discuss the steps for protein synthesis and characterization, validate proof-of-concept transcriptional regulation, and discuss its applications in molecular computing, diagnostics, and molecular information processing. https://www.jove.com/v/62073 566 2021-12-29T21:00:00+00:00 JoVE no https://visualize.jove.com/9100228-the-limbic-system-an-overview-of-the-anatomy-and-its-development monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14905.jpg Cerebrum: Anatomical Overview I The main and largest component of the human brain is the cerebrum. The cerebrum consists of two main parts: the cerebral cortex, an outer layer with wrinkles or folds known as gyri and shallow grooves called sulci, and a deeper region beneath it. The cerebrum divides into two distinct hemispheres and contains five different lobes: the frontal, parietal, temporal, occipital, and insula. The central sulcus separates the frontal and parietal lobes and two functionally important gyri — the... https://www.jove.com/v/14905 86 2025-06-13T16:09:38+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14906.jpg Cerebrum: Anatomical Overview II Each cerebral hemisphere can be divided into three main regions. The outermost region, the cerebral cortex, is a thin layer (2 to 4 millimeters thick) made up of gray matter, consisting of neuron cell bodies, dendrites, glial cells, and blood vessels. The middle region, or white matter, is primarily composed of myelinated nerve fibers organized into three types of large tracts: association fibers, commissures, and projection fibers. Association fibers connect different areas within the same... https://www.jove.com/v/14906 71 2025-06-13T16:09:59+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14909.jpg Diencephalon: Anatomical Regions The diencephalon, etymologically translated as 'through brain,' plays an integral role as the conduit between the cerebrum and the vast extent of the nervous system. However, the olfactory system is an exception, as it interfaces directly with the cerebrum. The diencephalon, deeply ensconced beneath the cerebrum, primarily consists of three paired structures — the thalamus, hypothalamus, and epithelamus. It also includes accessory structures such as the subthalamus, which houses the subthalamic... https://www.jove.com/v/14909 90 2025-06-13T16:11:34+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14911.jpg Diencephalon: Hypothalamus and Coordination The hypothalamus is a small yet highly complex and essential brain region that plays a crucial role in regulating various bodily functions. Anatomically, it is located at the base of the brain, just above the brainstem and below the thalamus, forming part of the limbic system. The hypothalamus interacts with other brain regions, including the pituitary gland, through a direct physical connection called the hypothalamic-pituitary axis. The hypothalamus receives somatic and visceral inputs and... https://www.jove.com/v/14911 83 2025-06-13T16:12:02+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14915.jpg Functional Brain Systems: Limbic System The limbic system, often called the "emotional brain," is a complex set of structures located deep within the brain. The intricate network of the limbic system supports a wide range of psychological functions, from emotional regulation to memory formation and sensory processing. This functional brain region encompasses specific parts of the diencephalon and the cerebrum, integrating the higher mental functions of the cerebral cortex with the primitive emotional responses of the deep brain... https://www.jove.com/v/14915 75 2025-06-13T16:15:56+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17746.jpg Organization of the Brain The brain is an integral component of the nervous system and serves as the center for processing sensory inputs, making decisions, and directing bodily actions. This complex organ is organized into three primary sections: the hindbrain, midbrain, and forebrain, each responsible for a range of vital functions. Hindbrain The hindbrain, located at the base of the brain, plays a vital role in regulating automatic processes that sustain life. It includes the medulla oblongata, which is essential for... https://www.jove.com/v/17746 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56246.jpg Exploring Deep Space - Uncovering the Anatomy of Periventricular Structures to Reveal the Lateral Ventricles of the Human Brain This paper demonstrates the effective use of a fiber dissection method to reveal the superficial white matter tracts and periventricular structures of the human brain, in three-dimensional space, to aid student comprehension of ventricular morphology. https://www.jove.com/v/56246 1033 2017-10-22T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61753.jpg Horizontal Hippocampal Slices of the Mouse Brain This article aims to describe a systematic protocol to obtain horizontal hippocampal brain slices in mice. The objective of this methodology is to preserve the integrity of hippocampal fiber pathways, such as the perforant path and the mossy fiber tract to assess dentate gyrus related neurological processes. https://www.jove.com/v/61753 539 2020-09-22T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61941.jpg Microdissection of Mouse Brain into Functionally and Anatomically Different Regions We present a hands-on, step-by-step, rapid protocol for mouse brain removal and dissection of discrete regions from fresh brain tissue. Obtaining brain regions for molecular analysis has become routine in many neuroscience labs. These brain regions are immediately frozen to obtain high quality transcriptomic data for system level analysis. https://www.jove.com/v/61941 486 2021-02-15T20:30:00+00:00 JoVE no https://visualize.jove.com/9108983-concepts-properties-and-applications-of-linear-systems-to-describe-distribution-identify-input-and-control-endogenous-substances-and-drugs-in-biological-systems monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16031.jpg Control Systems Control systems are everywhere in contemporary society, influencing diverse applications from aerospace to automated manufacturing. These systems can be found naturally within biological processes, such as blood sugar regulation and heart rate adjustment in response to stress, as well as in man-made systems like elevators and automated vehicles. A control system is essentially a network of subsystems and processes that collaboratively convert specific inputs into desired outputs. At the heart... https://www.jove.com/v/16031 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16045.jpg Classification of Systems-I Linearity is a system property characterized by a direct input-output relationship, combining homogeneity and additivity. Homogeneity dictates that if an input x(t) is multiplied by a constant c, the output y(t) is multiplied by the same constant. Mathematically, this is expressed as: Additivity means that the response to the sum of multiple inputs is the sum of their individual responses. For inputs x1(t) and x2(t) producing outputs y1(t) and y2(t), respectively: Combining homogeneity and... https://www.jove.com/v/16045 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16047.jpg Linear time-invariant Systems A system is linear if it displays the characteristics of homogeneity and additivity, together termed the superposition property. This principle is fundamental in all linear systems. Linear time-invariant (LTI) systems include systems with linear elements and constant parameters. The input-output behavior of an LTI system can be fully defined by its response to an impulsive excitation at its input. Once this impulse response is known, the system's reaction to any other input can be calculated... https://www.jove.com/v/16047 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16094.jpg Feedback control systems Feedback control systems are categorized in various ways based on their design, analysis, and signal types. Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity... https://www.jove.com/v/16094 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16514.jpg Drug Distribution: Overview Drug distribution within the body is a dynamic process involving the movement of a drug in two directions across various compartments: from the bloodstream into tissues (tissue uptake) and from tissues back into the bloodstream (tissue release or redistribution). This process is passive and primarily driven by two variables: the concentration gradient between the bloodstream and the extravascular tissues and the drug's ability to cross the cell membrane. Initially, the free drug in the... https://www.jove.com/v/16514 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16603.jpg Drug Distribution as One-Compartment Model and Elimination by Nonlinear Pharmacokinetics: Overview Drug administration can occur through various routes, each of which may result in a different process of elimination. This process is often mixed with nonlinear and linear processes. It's important to understand that a single drug can be metabolized into different metabolites through parallel processes. For instance, consider the metabolism of sodium salicylate. This compound is metabolized into two distinct substances: a glucuronide and a glycine conjugate. The rate of conjugation depends on... https://www.jove.com/v/16603 85 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50168.jpg The Use of Chemostats in Microbial Systems Biology Cell growth rate is a regulated process and a primary determinant of cell physiology. Continuous culturing using chemostats enables extrinsic control of cell growth rate by nutrient limitation facilitating the study of molecular networks that control cell growth and how those networks evolve to optimize cell growth. https://www.jove.com/v/50168 799 2013-10-15T03:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59235.jpg In vivo Application of the REMOTE-control System for the Manipulation of Endogenous Gene Expression This protocol outlines the steps needed to generate a model system in which the transcription of an endogenous gene of interest can be conditionally controlled in live animals or cells using enhanced lac repressor and/or tet activator systems. https://www.jove.com/v/59235 534 2019-03-29T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68448.jpg Efficient Sampling of Genetically Encoded Biosensor Design Space Enabled with a Design of Experiments and Automation Workflow This protocol provides a method for the systematic global optimization of genetically encoded biosensors through automation-assisted genetic library generation and assessment. This is coupled with design-of-experiment methodologies to streamline experimentation and enable the selection of genetic components to tune biosensors to specific design outcomes. https://www.jove.com/v/68448 538 2025-10-17T19:50:00+00:00 JoVE no https://visualize.jove.com/9112213-large-scale-isolation-of-cd34-cells-using-the-amgen-cell-selection-device-results-in-high-levels-of-purity-and-recovery monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3183.jpg Isolation of CD133+ Liver Stem Cells for Clonal Expansion Here we describe the isolation of CD133 expressing liver stem cells and cancer stem cells from whole murine liver, a process that requires tissue digestion, cell enrichment, and flow cytometry isolation. We include methods for advanced single cell isolation and clonal expansion. https://www.jove.com/v/3183 726 2011-10-10T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13371.jpg Overview Of Cell Separation And Isolation Cell separation was first achieved in 1964 by S. H. Seal, who separated large tumor cells from the smaller blood cells using filtration. Two years later, Pohl and Hawk performed experiments on how cells respond differently to a nonuniform electric field based on the cell type. Such observations were the inception of cell separation methods, which allow isolating a single cell type from a heterogeneous sample. Commonly used cell separation techniques include filtration, density gradient... https://www.jove.com/v/13371 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55284.jpg Isolation and Enrichment of Liver Progenitor Subsets Identified by a Novel Surface Marker Combination Liver injuries are accompanied by progenitor cell expansion that represents a heterogeneous cell population. Novel classification of this cellular compartment allows for the distinguishing of multiple subsets. The method described here illustrates the flow cytometry analysis and high purity isolation of various subsets that can be used for further assays. https://www.jove.com/v/55284 532 2017-02-18T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62499.jpg Leukodepletion Filters-Derived CD34+ Cells As a Cell Source to Study Megakaryocyte Differentiation and Platelet Formation This protocol describes in detail all the steps involved in obtaining leukofilter-derived CD34+ hematopoietic progenitors and their in vitro differentiation and maturation into proplatelet-bearing megakaryocytes that are able to release platelets in the culture medium. This procedure is useful for in-depth analysis of cellular and molecular mechanisms controlling megakaryopoiesis. https://www.jove.com/v/62499 417 2021-05-20T21:00:00+00:00 JoVE no https://visualize.jove.com/9113352-self-organized-marginal-stability-resulting-from-inconsistency-between-fuzzy-logic-and-deterministic-logic-an-application-to-biological-systems monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14362.jpg Stability of Equilibrium Configuration: Problem Solving The stability of equilibrium configurations is an important concept in physics, engineering, and other related fields. In simple terms, it refers to the tendency of an object or system to return to its equilibrium position after being disturbed. The stability of an equilibrium configuration can be analyzed by considering the potential energy function of the system and examining its behavior near the equilibrium point. Problem-solving in the context of the stability of equilibrium configuration... https://www.jove.com/v/14362 73 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14512.jpg Propagation of Uncertainty from Systematic Error The atomic mass of an element varies due to the relative ratio of its isotopes. A sample's relative proportion of oxygen isotopes influences its average atomic mass. For instance, if we were to measure the atomic mass of oxygen from a sample, the mass would be a weighted average of the isotopic masses of oxygen in that sample. Since a single sample is not likely to perfectly reflect the true atomic mass of oxygen for all the molecules of oxygen on Earth, the mass we obtain from this particular... https://www.jove.com/v/14512 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16045.jpg Classification of Systems-I Linearity is a system property characterized by a direct input-output relationship, combining homogeneity and additivity. Homogeneity dictates that if an input x(t) is multiplied by a constant c, the output y(t) is multiplied by the same constant. Mathematically, this is expressed as: Additivity means that the response to the sum of multiple inputs is the sum of their individual responses. For inputs x1(t) and x2(t) producing outputs y1(t) and y2(t), respectively: Combining homogeneity and... https://www.jove.com/v/16045 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16053.jpg BIBO stability of continuous and discrete -time systems System stability is a fundamental concept in signal processing, often assessed using convolution. For a system to be considered bounded-input bounded-output (BIBO) stable, any bounded input signal must produce a bounded output signal. A bounded input signal is one where the modulus does not exceed a certain constant at any point in time. To determine the BIBO stability, the convolution integral is utilized when a bounded continuous-time input is applied to a Linear Time-Invariant (LTI) system. https://www.jove.com/v/16053 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16058.jpg Pole and System Stability The transfer function is a fundamental concept representing the ratio of two polynomials. The numerator and denominator encapsulate the system's dynamics. The zeros and poles of this transfer function are critical in determining the system's behavior and stability. Simple poles are unique roots of the denominator polynomial. Each simple pole corresponds to a distinct solution to the system's characteristic equation, typically resulting in exponential decay terms in the system's response.<br... https://www.jove.com/v/16058 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16124.jpg Root Loci for Positive-Feedback Systems The Hartley oscillator is a positive feedback system that sustains oscillations by feeding the output back to the input in phase, thereby reinforcing the signal. Positive feedback systems can be viewed as negative feedback systems with inverted feedback signals. In these systems, the root locus encompasses all points on the s-plane where the angle of the system transfer function equals 360 degrees. The construction rules for the root locus in positive feedback systems are similar to those in... https://www.jove.com/v/16124 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58139.jpg In Vitro Reconstitution of Self-Organizing Protein Patterns on Supported Lipid Bilayers We provide a protocol for in vitro self-organization assays of MinD and MinE on a supported lipid bilayer in an open chamber. Additionally, we describe how to enclose the assay in lipid-clad PDMS microcompartments to mimic in vivo conditions by reaction confinement. https://www.jove.com/v/58139 490 2018-07-28T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63084.jpg Inherent Dynamics Visualizer, an Interactive Application for Evaluating and Visualizing Outputs from a Gene Regulatory Network Inference Pipeline The Inherent Dynamics Visualizer is an interactive visualization package that connects to a gene regulatory network inference tool for enhanced, streamlined generation of functional network models. The visualizer can be used to make more informed decisions for parameterizing the inference tool, thus increasing confidence in the resulting models. https://www.jove.com/v/63084 644 2021-12-07T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68955.jpg Age-dependent Dynamics of Locomotion in Caenorhabditis elegans : A Lyapunov Exponent Analysis This study examines the effect of age on locomotion in C. elegans by measuring the largest Lyapunov exponent (LLE). As they age, C. elegans show an increase and subsequent decline in motor control. Results show a peak LLE at five days, followed by a decline as the worms age. https://www.jove.com/v/68955 404 2025-09-23T21:45:00+00:00 JoVE no https://visualize.jove.com/9115844-modulation-of-membrane-potential-and-ionic-currents-by-the-at1-and-at2-receptors-of-angiotensin-ii monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10893.jpg Hormonal Regulation The renin-aldosterone system is an endocrine system which guides the renal absorption of water and electrolytes, thus managing blood pressure and osmoregulation. Activation of the system begins in the kidneys with a small cluster of cells adjacent to the afferent and efferent blood vessels of the renal corpuscle. As the nephrons are filtering blood, juxtaglomerular cells monitor blood pressure. If they detect a decrease in pressure, they release the hormone renin into the bloodstream. <br... https://www.jove.com/v/10893 93 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15020.jpg Antihypertensive Drugs: Action of β 1 Blockers β1-receptors are primarily located in the heart and kidneys. In cardiac myocytes, these receptors interact with neurotransmitters released by the sympathetic nervous system during heightened activity or danger. As a result, β1-receptors get activated, initiating a series of biochemical processes. Excessive activation of beta receptors due to chronic stress can abnormally increase heart rate and contractility, resulting in high blood pressure or hypertension. To counteract this, β1-blockers... https://www.jove.com/v/15020 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15023.jpg Antihypertensive Drugs: Angiotensin-Converting Enzyme Inhibitors Angiotensin-converting enzyme (ACE), a vital component of the renin-angiotensin-aldosterone system, is abundant in lung endothelial cells. ACE converts the inactive decapeptide, angiotensin I, into the active octapeptide, angiotensin II. This potent vasoconstrictor narrows blood vessels, increasing resistance to blood flow and elevating blood pressure. Angiotensin II also stimulates aldosterone production, encouraging kidney cells to reabsorb more sodium and water from urine, thereby increasing... https://www.jove.com/v/15023 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15024.jpg Antihypertensive Drugs: Angiotensin II Receptor Blockers In the renin-angiotensin-aldosterone system, a hormone called angiotensin II plays a crucial role. It binds to the AT1 receptors in vascular smooth muscles coupled with Gq proteins. The activation of these receptors activates an enzyme called phospholipase C, which releases two molecules: inositol trisphosphate and diacylglycerol. These molecules cause a chain reaction that leads to the phosphorylation of myosin light chains and promotes interaction between actin and myosin, leading to smooth... https://www.jove.com/v/15024 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15025.jpg Antihypertensive Drugs: Direct Renin Inhibitors The renin-angiotensin-aldosterone system (RAAS) is an intricate physiological pathway involving numerous enzymes and hormones, including renin, angiotensin-converting enzyme (ACE), angiotensin I and II, and aldosterone. Imbalances within this system increase the production of angiotensin II and aldosterone. Increased angiotensin II levels promote vasoconstriction and blood pressure elevation. Concurrently, higher aldosterone levels stimulate sodium and water reabsorption in the kidneys,... https://www.jove.com/v/15025 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15037.jpg Heart Failure Drugs: Inhibitors of Renin-Angiotensin System The activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) contributes to cardiac remodeling, and inhibiting the RAAS is a pharmacological target in heart failure management. As a result, neurohumoral modulation is a crucial treatment principle for managing heart failure. This approach involves using medications like ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), β-blockers, mineralocorticoid receptor antagonists (MRAs), and neutral... https://www.jove.com/v/15037 86 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52850.jpg Single-channel Analysis and Calcium Imaging in the Podocytes of the Freshly Isolated Glomeruli Changes in the intracellular calcium levels in the podocytes are one of the most important means to control the filtration function of glomeruli. Here we explain a high-throughput approach that allows detection of real-time calcium handling and single ion channels activity in the podocytes of the freshly isolated glomeruli. https://www.jove.com/v/52850 739 2015-06-27T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53866.jpg Receptor Autoradiography Protocol for the Localized Visualization of Angiotensin II Receptors Here we present a protocol to describe the localization of angiotensin II Type 1 receptors in the rat brain by quantitative, densitometric, in vitro receptor autoradiography using an iodine-125 labeled analog of angiotensin II. https://www.jove.com/v/53866 723 2016-06-07T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55177.jpg Live Cell Imaging and 3D Analysis of Angiotensin Receptor Type 1a Trafficking in Transfected Human Embryonic Kidney Cells Using Confocal Microscopy Here we present a protocol to image cells expressing green fluorescent protein-tagged angiotensin type 1a receptors during endocytosis initiated by angiotensin II treatment. This technique includes labeling lysosomes with a second fluorescent marker, and then utilizing software to analyze the co-localization of receptor and lysosome in three dimensions over time. https://www.jove.com/v/55177 591 2017-03-27T20:00:00+00:00 JoVE no https://visualize.jove.com/9125166-angiotensin-iv-stimulates-the-proliferation-of-rat-anterior-pituitary-cells-in-vitro monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3078.jpg Rat Mesentery Angiogenesis Assay Normal adult vascularized mammalian tissue that lacks physiologic angiogenesis and that has not been exposed to surgical intervention is used to study: (i) the initiation and development of angiogenesis following intraperitoneal administration of test agents; and (ii) modification of angiogenesis following systemic administration of selected test agents. https://www.jove.com/v/3078 1110 2011-06-18T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15023.jpg Antihypertensive Drugs: Angiotensin-Converting Enzyme Inhibitors Angiotensin-converting enzyme (ACE), a vital component of the renin-angiotensin-aldosterone system, is abundant in lung endothelial cells. ACE converts the inactive decapeptide, angiotensin I, into the active octapeptide, angiotensin II. This potent vasoconstrictor narrows blood vessels, increasing resistance to blood flow and elevating blood pressure. Angiotensin II also stimulates aldosterone production, encouraging kidney cells to reabsorb more sodium and water from urine, thereby increasing... https://www.jove.com/v/15023 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15024.jpg Antihypertensive Drugs: Angiotensin II Receptor Blockers In the renin-angiotensin-aldosterone system, a hormone called angiotensin II plays a crucial role. It binds to the AT1 receptors in vascular smooth muscles coupled with Gq proteins. The activation of these receptors activates an enzyme called phospholipase C, which releases two molecules: inositol trisphosphate and diacylglycerol. These molecules cause a chain reaction that leads to the phosphorylation of myosin light chains and promotes interaction between actin and myosin, leading to smooth... https://www.jove.com/v/15024 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50366.jpg Culturing Primary Rat Inner Medullary Collecting Duct Cells Arginine-vasopressin (AVP) controls fine-tuning of body water homeostasis through facilitating water reabsorption by renal principal cells. Here, we present a protocol for the cultivation of primary rat inner medullary collecting duct cells suitable for the elucidation of molecular mechanisms underlying AVP-mediated water reabsorption. https://www.jove.com/v/50366 371 2013-06-21T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54418.jpg Intravascular Delivery of Biologics to the Rat Kidney The administration of drugs for recovery of kidney function requires control of the localization and distribution of the therapeutic compound. Here, we describe in detail a simple technique for intrarenal delivery of drugs in rats. This procedure may be easily performed with no mortality and high reproducibility. https://www.jove.com/v/54418 449 2016-09-01T22:00:00+00:00 JoVE no https://visualize.jove.com/9163855-cavocaval-liver-transplantation-without-venovenous-bypass-and-without-temporary-portocaval-shunting-the-ideal-technique-for-adult-liver-grafting monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4143.jpg Orthotopic Liver Transplantation in Rats We present an easy-to-establish revision of the classical two-cuff technique for orthotopic liver transplantation in rat. https://www.jove.com/v/4143 1105 2012-07-01T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52055.jpg Technique of Porcine Liver Procurement and Orthotopic Transplantation using an Active Porto-Caval Shunt Experimental animal research plays a pivotal role in the development of clinical transplantation practice. The porcine orthotopic liver transplantation model (OLTx) closely resembles human conditions and is frequently used in clinically oriented research. The following protocol contains all information for a reliable porcine OLTx model using an active porto-caval-jugular shunt. https://www.jove.com/v/52055 747 2015-05-07T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64152.jpg Porcine Liver Transplantation Without Veno-Venous Bypass As an Extended Criteria Donor Model In this protocol, a model of porcine orthotopic liver transplantation after static cold storage of donor organs for 20 h without the use of a veno-venous bypass during engraftment is described. The approach uses a simplified surgical technique with minimization of the anhepatic phase and sophisticated volume and vasopressor management. https://www.jove.com/v/64152 769 2022-08-17T21:00:00+00:00 JoVE no https://visualize.jove.com/9201158-intraoperative-autologous-transfusion-during-elective-infrarenal-aortic-reconstruction-a-decision-analysis-model monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/59983.jpg Murine Cervical Aortic Transplantation Model using a Modified Non-Suture Cuff Technique Here, we present a protocol of heterotopic aortic transplantation in mice using the non-suture cuff technique in a cervical murine model. This model can be used to study the underlying pathology of chronic allograft vasculopathy (CAV) and can help evaluate new therapeutic agents in order to prevent its formation. https://www.jove.com/v/59983 611 2019-11-02T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60956.jpg An Immunological Model for Heterotopic Heart and Cardiac Muscle Cell Transplantation in Rats We describe a model of heterotopic abdominal heart transplantation in rats, implying modifications of current strategies, which lead to a simplified surgical approach. Additionally, we describe a novel rejection model by in-ear injection of vital cardiac muscle cells, allowing further transplant immunological analyses in rats. https://www.jove.com/v/60956 565 2020-05-08T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64813.jpg Modified Heterotopic Abdominal Heart Transplantation and a Novel Aortic Regurgitation Model in Rats This study demonstrates a reproducible heterotopic abdominal heart transplantation technique in rats that beginners can learn and perform. Additionally, a novel aortic regurgitation model in rats is generated by performing heterotopic abdominal heart transplantation and damaging the donor's aortic valve using a guidewire after harvesting. https://www.jove.com/v/64813 812 2023-06-02T19:00:00+00:00 JoVE no https://visualize.jove.com/9216130-linear-and-nonlinear-arma-model-parameter-estimation-using-an-artificial-neural-network monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16099.jpg Linear Approximation in Frequency Domain Linear systems are characterized by two main properties: superposition and homogeneity. Superposition allows the response to multiple inputs to be the sum of the responses to each individual input. Homogeneity ensures that scaling an input by a scalar results in the response being scaled by the same scalar. In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear. https://www.jove.com/v/16099 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16103.jpg Linear Approximation in Time Domain Nonlinear systems often require sophisticated approaches for accurate modeling and analysis, with state-space representation being particularly effective. This method is especially useful for systems where variables and parameters vary with time or operating conditions, such as in a simple pendulum or a translational mechanical system with nonlinear springs. For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length, the... https://www.jove.com/v/16103 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16586.jpg Mechanistic Models: Compartment Models in Algorithms for Numerical Problem Solving Mechanistic models play a crucial role in algorithms for numerical problem-solving, particularly in nonlinear mixed effects modeling (NMEM). These models aim to minimize specific objective functions by evaluating various parameter estimates, leading to the development of systematic algorithms. In some cases, linearization techniques approximate the model using linear equations. In individual population analyses, different algorithms are employed, such as Cauchy's method, which uses a... https://www.jove.com/v/16586 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16604.jpg Parameters Affecting Nonlinear Elimination: Zero-Order Input, First-Order Absorption and Two-Compartment Model Drugs administered through various routes can lead to nonlinear elimination, resulting in complex pharmacokinetic behaviors crucial to understanding efficacious drug dosing. When a drug is administered through a constant intravenous infusion and eliminated via nonlinear pharmacokinetics, it follows zero-order input. For example, oral drugs undergo first-order absorption upon administration and are eliminated through nonlinear pharmacokinetics. In the case of subcutaneously administered drugs,... https://www.jove.com/v/16604 73 JoVE no https://cloudfront.jove.com/files/ftp_upload/19809/19809_article_thumb_19809_TN.jpg Linearization and Approximation Linearization is a mathematical technique used to approximate complex, nonlinear functions with simpler linear models in the vicinity of a chosen reference point. The method is based on the idea that, although a function may be difficult to evaluate exactly, its behavior near a specific input value can often be closely approximated by the tangent line at that point. This approach is particularly useful when small deviations from a known value are involved.Consider the square root function, for... https://www.jove.com/v/19809 86 2026-01-12T20:24:20+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19810/19810_article_thumb_19810_TN.jpg Application of Linearization and Approximation A drone flying through complex terrain often relies on more than one sensing method to estimate small changes in altitude. Along with direct measurements, air pressure provides a useful indirect indicator of vertical movement. Atmospheric pressure decreases as altitude increases, and this relationship is commonly described using an exponential model. Although accurate, converting pressure measurements into altitude values requires calculations that are too complex to perform repeatedly during... https://www.jove.com/v/19810 89 2026-01-12T20:24:59+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65931.jpg Artificial Intelligence-Based System for Detecting Attention Levels in Students This paper proposes an artificial intelligence-based system to automatically detect whether students are paying attention to the class or are distracted. This system is designed to help teachers maintain students' attention, optimize their lessons, and dynamically introduce modifications in order for them to be more engaging. https://www.jove.com/v/65931 397 2023-12-15T22:10:00+00:00 JoVE no https://visualize.jove.com/9219865-the-effects-of-type-i-and-type-ii-corticosteroid-receptor-agonists-on-exploratory-behavior-and-spatial-memory-in-the-y-maze monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/56988.jpg A Behavioral Assay for Investigating the Role of Spatial Memory During Instinctive Defense in Mice This protocol describes a behavioral assay, based on the Barnes maze test, to study how instinctive defensive actions are modified by the knowledge of spatial environment. https://www.jove.com/v/56988 349 2018-07-21T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61548.jpg Chronic Stress Shifts Effort-Related Choice Behavior in a Y-Maze Barrier Task in Mice The Y-maze barrier task is a behavior test that examines motivation to expend effort for reward. Here, we discuss testing multiple well-validated chronic stressors including chronic corticosterone and social defeat stress with this behavior, as well as the novel chronic non-discriminatory social defeat stress (CNSDS), which is effective in females. https://www.jove.com/v/61548 577 2020-08-13T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66456.jpg An Appetitive Spatial Working Memory Task for Mice in a Semi-Automated 8-Arm Radial Maze, Reducing Fearful Memory Association in the Maze Most behavior experiments for rodents were originally devised for rats. Due to the behavioral differences between rats and mice, sometimes modifications are required for mice. We present a method to test spatial working memory in mice, minimizing the stress during the working memory task. https://www.jove.com/v/66456 864 2025-07-29T19:30:00+00:00 JoVE no https://visualize.jove.com/9230458-solid-phase-synthesis-of-omega-agatoxin-iva-a-p-type-calcium-channel-blocker monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12244.jpg Ligand-gated Ion Channels Ligand-gated ion channels are transmembrane proteins with a channel for ions to pass through and a binding site for a ligand. The channel opens only when a ligand attaches to the binding site. Three Subfamilies of Ligand-gated Ion Channels Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that include the... https://www.jove.com/v/12244 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13328.jpg Calmodulin-dependent Signaling Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change. The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,... https://www.jove.com/v/13328 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12244.jpg Ligand-gated Ion Channels Ligand-gated ion channels are transmembrane proteins with a channel for ions to pass through and a binding site for a ligand. The channel opens only when a ligand attaches to the binding site. Three Subfamilies of Ligand-gated Ion Channels Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that include the... https://www.jove.com/v/14997 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15022.jpg Antihypertensive Drugs: Action of Calcium Channel Blockers Calcium ions are essential to contract smooth muscle cells in blood vessels. They enter these cells through voltage-dependent calcium channels, specifically L-type calcium channels in the cell membrane. These L-type calcium channels are integral to the excitation-contraction coupling process in smooth muscle. When a stimulus is received by smooth muscle cells, their membrane depolarizes. This alteration in membrane potential instigates the opening of L-type calcium channels. As a result,... https://www.jove.com/v/15022 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15029.jpg Antiarrhythmic Drugs: Class I Agents as Sodium Channel Blockers Class I antiarrhythmic drugs are used to treat various types of arrhythmias or irregular heart rhythms. These drugs block the sodium (Na+) channels in the cardiac cells, thereby affecting the movement of electrical impulses across the heart. Class I antiarrhythmic drugs are divided into three subgroups: Class IA, Class IB, and Class IC, each with distinct mechanisms of action and effects on the heart. Class 1A Antiarrhythmic Drugs: These drugs work by moderately blocking sodium channels,... https://www.jove.com/v/15029 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15032.jpg Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers Class IV antiarrhythmic drugs, such as verapamil and diltiazem, block calcium channels. They primarily affect the heart, slowing the conduction in calcium-dependent tissues like the SA and AV nodes. These drugs manage reentrant supraventricular tachycardia (SVT) and reduce ventricular rate in atrial flutter/fibrillation. Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and... https://www.jove.com/v/15032 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50145.jpg Isolation and Kv Channel Recordings in Murine Atrial and Ventricular Cardiomyocytes Kv channel dysfunction is associated with cardiac arrhythmias. In order to study the molecular mechanisms that lead to such arrhythmias we utilize a systematic protocol for isolation of atrial and ventricular cardiomyocytes from Kv channel ancillary subunit knockout mice. Isolated cardiomyocytes can then immediately be used for cellular electrophysiological studies, biochemical or immunofluorescence (IF) assays. https://www.jove.com/v/50145 693 2013-03-12T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57842.jpg Methods for the Discovery of Novel Compounds Modulating a Gamma-Aminobutyric Acid Receptor Type A Neurotransmission Here, we present protocols to discover compounds active at GABAA receptors, from the binding to the physiology and pharmacology. https://www.jove.com/v/57842 436 2018-08-16T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58368.jpg Synthesis and Structure Determination of µ-Conotoxin PIIIA Isomers with Different Disulfide Connectivities Cysteine-rich peptides fold into distinct three-dimensional structures depending on their disulfide connectivity. Targeted synthesis of individual disulfide isomers is required when buffer oxidation does not lead to the desired disulfide connectivity. The protocol deals with the selective synthesis of 3-disulfide-bonded peptides and their structural analysis using NMR and MS/MS studies. https://www.jove.com/v/58368 704 2018-10-02T21:00:00+00:00 JoVE no https://visualize.jove.com/9246870-adaptive-autoregressive-modeling-used-for-single-trial-eeg-classification monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/59117.jpg Simultaneous Eye Tracking and Single-Neuron Recordings in Human Epilepsy Patients We describe a method to conduct single-neuron recordings with simultaneous eye tracking in humans. We demonstrate the utility of this method and illustrate how we used this approach to obtain neurons in the human medial temporal lobe that encode targets of a visual search. https://www.jove.com/v/59117 463 2019-06-17T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60249.jpg Statistical Modelling of Cortical Connectivity Using Non-invasive Electroencephalograms Standard EEG analysis techniques offer limited insight into nervous system function. Deriving statistical models of cortical connectivity offers far greater ability to investigate underlying network dynamics. Improved functional assessment opens new possibilities for diagnosis, prognostication, and outcome prediction in nervous system diseases. https://www.jove.com/v/60249 531 2019-11-01T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66913.jpg Memorization-Based Training and Testing Paradigm for Robust Vocal Identity Recognition in Expressive Speech Using Event-Related Potentials Analysis The study introduces a training-testing paradigm to investigate old/new effects of event-related potentials in confident and doubtful prosodic scenarios. Data reveals an enhanced late positive component between 400-850 ms at Pz and other electrodes. This pipeline can explore factors beyond speech prosody and their influence on cue-binding target identification. https://www.jove.com/v/66913 348 2024-08-09T20:40:00+00:00 JoVE no https://visualize.jove.com/9263228-a-mathematical-model-of-the-intracranial-system-including-autoregulation monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15301.jpg Neural Regulation of Blood Pressure The neural regulation of blood pressure involves intricate interactions between the autonomic nervous system (ANS) and cardiovascular system, ensuring adequate perfusion of tissues. This regulation primarily occurs through baroreceptor and chemoreceptor reflexes, involving both short-term and long-term mechanisms. Baroreceptor Reflex Baroreceptors, located in the carotid sinuses and aortic arch, detect changes in blood pressure. When blood pressure rises, these stretch-sensitive receptors... https://www.jove.com/v/15301 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15304.jpg Autoregulation of Blood Flow Autoregulation mechanisms are characterized by their inherent capacity for self-regulation without necessitating specific nervous stimulation or endocrine control. These mechanisms facilitate the adjustment of blood flow and, therefore, perfusion specific to each tissue region. This self-regulation encompasses chemical signals and myogenic controls. Chemical Signaling in Autoregulation Chemical signaling operates at the precapillary sphincter level, inciting either contraction or relaxation. https://www.jove.com/v/15304 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15312.jpg Arteries of the Head and Neck The human body's intricate network of arteries ensures that every organ system receives the necessary oxygen and nutrients for optimal function. The arterial network in the head and neck region is particularly complex, providing vital blood flow to the brain, eyes, and other critical structures. Prominent arteries in this region include the internal carotid arteries and the vertebral arteries. The internal carotid arteries supply blood to the anterior portion of the cerebrum. They enter the... https://www.jove.com/v/15312 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/40933/40933_article_thumb_40933.jpg Increased Intracranial Pressure l: Introduction Intracranial hypertension is a sustained elevation of intracranial pressure (ICP) above 22 mm Hg. In supine adults, normal ICP is ~7–15 mm Hg.The rigid, nonexpandable cranium contains three components—brain tissue, blood, and cerebrospinal fluid (CSF)—that total ~1,700 mL in a typical adult: 1,400 mL brain (~80%), 150 mL blood (~10%), and 150 mL CSF (~10%). According to the Monro–Kellie doctrine, total intracranial volume is effectively fixed. When one component expands, CSF and venous blood... https://www.jove.com/v/40933 74 2026-04-13T23:55:57+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40934/40934_article_thumb_40934.jpg Increased Intracranial Pressure ll: Pathophysiology Increased intracranial pressure (ICP) refers to a potentially life-threatening rise in pressure inside the skull. This usually happens when there is a major change in the volume of brain tissue, blood, or cerebrospinal fluid (CSF) — the three components inside the skull. According to the Monro-Kellie doctrine, if the volume of one component increases, the volumes of the other components must decrease to maintain normal pressure. If this does not happen, ICP rises.The process often begins with... https://www.jove.com/v/40934 89 2026-04-13T23:56:03+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40937/40937_article_thumb_40937.jpg Cerebral Edema l: Introduction Cerebral edema is a pathological increase in brain water content that disrupts intracranial pressure regulation and impairs neurological function. Because the cranial vault is rigid, even modest increases in tissue volume can compromise cerebral perfusion, distort neural structures, and initiate secondary injury. Cerebral edema develops through four principal mechanisms: vasogenic, cytotoxic, interstitial, and ionic.Vasogenic EdemaVasogenic edema arises from disruption of the blood–brain... https://www.jove.com/v/40937 79 2026-04-13T23:56:01+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51082.jpg Assessing Cerebral Autoregulation via Oscillatory Lower Body Negative Pressure and Projection Pursuit Regression Cerebral perfusion is maintained across a range of pressures via cerebral autoregulation. However, characterizing autoregulation requires prominent pressure fluctuations at regulated frequencies. The described protocol will show how oscillatory lower body negative pressure can generate pressure fluctuations to provide data for projection pursuit regression for quantification of the autoregulatory curve. https://www.jove.com/v/51082 686 2014-12-10T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60540.jpg Evaluation of Cerebral Blood Flow Autoregulation in the Rat Using Laser Doppler Flowmetry This article demonstrates the use of laser Doppler flowmetry to evaluate the ability of the cerebral circulation to autoregulate its blood flow during reductions in arterial blood pressure. https://www.jove.com/v/60540 432 2020-01-19T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61006.jpg Translaminar Autonomous System Model for the Modulation of Intraocular and Intracranial Pressure in Human Donor Posterior Segments We describe and detail the use of the translaminar autonomous system. This system utilizes the human posterior segment to independently regulate the pressure inside the segment (intraocular) and surrounding the optic nerve (intracranial) to generate a translaminar pressure gradient that mimics features of glaucomatous optic neuropathy. https://www.jove.com/v/61006 535 2020-04-24T22:00:00+00:00 JoVE no https://visualize.jove.com/9267590-design-and-validation-of-an-intelligent-patient-monitoring-and-alarm-system-based-on-a-fuzzy-logic-process-model monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13286.jpg Pulse rhythm Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding. Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle... https://www.jove.com/v/13286 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13539.jpg Data Validation Data validation is an essential part of a comprehensive assessment. Validation is confirming or verifying and opening the door to gathering more assessment data as it clarifies vague or unclear data. The process of checking and verifying the collected information is called data validation. The primary purpose of data validation is to ensure data is as free from error, bias, and misinterpretation as possible. Nursing assessment guides are generally based on holistic models rather than medical... https://www.jove.com/v/13539 63 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59019.jpg A Novel Digital Platform for a Monitored Home-based Cardiac Rehabilitation Program The aim is to promote a new approach to cardiac rehabilitation (CR), using a unique remote patient monitoring system that will enable healthcare providers to monitor CR patients at home at low cost, with the intention of making CR services more accessible and improving compliance. The study is currently underway. https://www.jove.com/v/59019 264 2019-04-19T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60361.jpg Design and Analysis for Fall Detection System Simplification We present a methodology based on multimodal sensors to configure a simple, comfortable and fast fall detection and human activity recognition system. The goal is to build a system for accurate fall detection that can be easily implemented and adopted. https://www.jove.com/v/60361 485 2020-04-06T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60794.jpg Implementation of a Real-Time Psychosis Risk Detection and Alerting System Based on Electronic Health Records using CogStack We demonstrate how to deploy a real-time psychosis risk calculation and alerting system based on CogStack, an information retrieval and extraction platform for electronic health records. https://www.jove.com/v/60794 451 2020-05-15T19:30:00+00:00 JoVE no https://visualize.jove.com/9279622-premature-mortality-in-italy-during-the-first-decade-of-the-aids-epidemic-1984-1993 monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2830.jpg Sequencing of Bacterial Microflora in Peripheral Blood: our Experience with HIV-infected Patients Our experiment will show how to perform a sequencing analysis of bacterial species translocating in peripheral blood of HIV positive patients. https://www.jove.com/v/2830 830 2011-06-11T22:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10825.jpg Retrovirus Life Cycles Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the retrovirus to... https://www.jove.com/v/10825 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15356.jpg Immunodeficiency Diseases Immunodeficiency disorders are conditions in which the immune system's ability to fight infectious disease and cancer is compromised or entirely absent. The immune system comprises a complex network of cells, tissues, and organs that work together to protect the body from potentially harmful invaders. When this system is deficient or not functioning properly, it leaves the body susceptible to infections, diseases, or other complications. There are three main causes of immunodeficiency disorders... https://www.jove.com/v/15356 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16319.jpg Sexually Transmitted Infections Sexually transmitted infections (STIs) are diseases transmitted primarily through unsafe sexual interactions. Bacteria, viruses, or parasites cause them and can result in severe health complications if untreated.ChlamydiaThe bacterium Chlamydia trachomatis is responsible for the disease Chlamydia, the most common STI in the United States. This peculiar pathogen requires human cells to reproduce, residing intracellularly. The initial infection often goes unnoticed because it typically does not... https://www.jove.com/v/16319 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16344.jpg Pulmonary Tuberculosis I Tuberculosis, often called TB, is a contagious illness primarily caused by Mycobacterium tuberculosis. It mainly affects the lung parenchyma but can also impact other body parts. Causative Organism The primary infectious agent causing tuberculosis is Mycobacterium tuberculosis, a slow-growing, acid-fast, aerobic rod that exhibits sensitivity to heat and ultraviolet light. Instances of Mycobacterium bovis and Mycobacterium avium contributing to the development of TB infection are rare. Mode of... https://www.jove.com/v/16344 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17597.jpg Prevalence and Incidence In statistical epidemiology and health sciences, two essential metrics—prevalence and incidence—are fundamental for understanding disease dynamics within a population. These measures enable public health officials, epidemiologists, and researchers to assess the burden of diseases, allocate resources effectively, and design impactful public health policies and interventions. Prevalence indicates the proportion of individuals in a population who have a specific disease or health condition at a... https://www.jove.com/v/17597 68 JoVE no https://cloudfront.jove.com/files/ftp_upload/40856/40856_article_thumb_40856.jpg Amebiasis Entamoeba histolytica, a protozoan parasite, is responsible for intestinal and extraintestinal amebiasis. Though a significant proportion of infections remain asymptomatic, approximately 50 million individuals annually are estimated to present with clinical disease, resulting in up to 100,000 deaths globally. The disease burden is disproportionately high in regions with lower socioeconomic status, such as parts of India, Africa, Mexico, and Latin America.Etiology and TransmissionThe infective... https://www.jove.com/v/40856 88 2026-05-20T21:29:57+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51400.jpg Rapid Screening of HIV Reverse Transcriptase and Integrase Inhibitors Here we describe cellular cytotoxicity and single round infectivity assays that allow for the rapid and accurate screening of compounds to determine their cellular cytotoxicity (CC50) and IC50 values against WT and drug resistant HIV-1. https://www.jove.com/v/51400 346 2014-04-10T04:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57013.jpg Ex Vivo Infection of Human Lymphoid Tissue and Female Genital Mucosa with Human Immunodeficiency Virus 1 and Histoculture Infection of human tissues with human immunodeficiency virus (HIV) ex vivo provides a valuable 3D model of virus pathogenesis. Here, we describe a protocol to process and infect tissue specimens from human tonsils and female genital mucosae with HIV-1 and maintain them in culture at the liquid-air interface. https://www.jove.com/v/57013 674 2018-10-12T20:00:00+00:00 JoVE no https://visualize.jove.com/9311886-adeno-associated-virus-rep-proteins-target-dna-sequences-to-a-unique-locus-in-the-human-genome monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10825.jpg Retrovirus Life Cycles Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the retrovirus to... https://www.jove.com/v/10825 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11572.jpg Retroviruses Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’... https://www.jove.com/v/11572 153 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11573.jpg LTR Retrotransposons LTR retrotransposons are class I transposable elements with long terminal repeats flanking an internal coding region. These elements are less abundant in mammals compared to other class I transposable elements. About 8 percent of human genomic DNA comprises LTR retrotransposons. Some of the common examples of LTR retrotransposons are Ty elements in yeast and Copia elements in Drosophila. The internal coding region of LTR retrotransposons and their mechanism of transposition closely resembles a... https://www.jove.com/v/11573 188 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12083.jpg Mechanisms of Retrovirus-induced Cancers Retroviruses are RNA viruses that have been shown to cause cancers in diverse species, including chickens, mice, cats, and monkeys. The RNA genomes of these viruses are first reverse-transcribed into single and then double-stranded DNA (dsDNA) copies. This dsDNA called proviral DNA then integrates into the host genome. Subsequently, the host cell transcribes the proviral DNA in concert with the chromosomal DNA. This leads to the production of viral RNA and proteins that assemble at the host... https://www.jove.com/v/12083 111 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12233.jpg Rous Sarcoma Virus (RSV) and Cancer Rous Sarcoma virus or RSV was discovered by F. Peyton Rous in the year 1911 as a filterable transmissible agent that could cause tumors in chickens. He won a Nobel Prize for this discovery in 1966. His experiments clearly demonstrated that some cancers could be caused by infectious agents and led to the discovery of many more cancer-causing viruses in animals as well as humans. RSV is a retrovirus that contains two copies of a plus-strand RNA genome. Its genome consists of four main open... https://www.jove.com/v/12233 63 JoVE no https://cloudfront.jove.com/files/ftp_upload/19592/19592_article_thumb_19592.jpg Viruses with RNA Genomes RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. This classification dictates how they exploit host cellular machinery for protein synthesis and replication. Some RNA viruses also utilize reverse transcription as part of their life cycle, further diversifying their replication strategies.Positive-Strand RNA VirusesPositive-strand RNA viruses have genomes that function directly as messenger... https://www.jove.com/v/19592 89 2025-06-12T16:30:23+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53296.jpg Isolation of Viral Replication Compartment-enriched Sub-nuclear Fractions from Adenovirus-infected Normal Human Cells We provide a novel strategy to isolate viral replication compartments (RC) from adenovirus (Ad)-infected human cells. This approach represents a cell-free system that can help to elucidate the molecular mechanisms regulating viral genome replication and expression as well as regulation of viral-host interactions established at the RC. https://www.jove.com/v/53296 622 2015-11-12T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65572.jpg Transgene Expression in Cultured Cells Using Unpurified Recombinant Adeno-Associated Viral Vectors Recombinant adeno-associated virus (rAAV) is widely used for clinical and preclinical gene delivery. An underappreciated use for rAAVs is the robust transduction of cultured cells without the need for purification. For researchers new to rAAV, we provide a protocol for transgene cassette cloning, crude vector production, and cell culture transduction. https://www.jove.com/v/65572 401 2023-10-20T21:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66550.jpg Isolation of Adeno-Associated Viral Vectors Through a Single-Step and Semi-Automated Heparin Affinity Chromatography Protocol This manuscript describes a detailed protocol for the generation and purification of adeno-associated viral vectors using an optimized heparin-based affinity chromatography method. It presents a simple, scalable, and cost-effective approach, eliminating the need for ultracentrifugation. The resulting vectors exhibit high purity and biological activity, proving their value in preclinical studies. https://www.jove.com/v/66550 552 2024-04-05T21:20:00+00:00 JoVE no https://visualize.jove.com/9331557-parotid-secretion-daily-patterns-and-measurement-with-ultrasonic-flow-probes-in-conscious-sheep monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/52354.jpg Surgical Technique for the Implantation of Tissue Engineered Vascular Grafts and Subsequent In Vivo Monitoring A step-by-step protocol for the inter-positional placement of Tissue Engineered Vessels (TEVs) into the carotid artery of a sheep using end-to-end anastomosis and real-time digital assessment in vivo until animal sacrifice. https://www.jove.com/v/52354 677 2015-04-03T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57203.jpg A Method for the Measurement of Salivary Gland Function in Mice Salivary gland hypofunction is a frequent consequence of autoimmune disease and radiation therapy. Reproducible evaluation of salivary gland function in mouse models of these diseases is a technical challenge. Here, a simple method for accurate and reproducible measurement of saliva production in mice is described. https://www.jove.com/v/57203 449 2018-01-25T22:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64551.jpg In Vivo Real-Time Study of Drug Effects on Carotid Blood Flow in the Ovine Fetus The present protocol describes a method to deliver drugs and gene expression-modifying agents perivascularly in an in utero developing fetus. Importantly, the effect of drugs/agents on blood flow can be measured with the progression of pregnancy. https://www.jove.com/v/64551 719 2023-04-28T21:40:00+00:00 JoVE no https://visualize.jove.com/9335268-functional-domains-of-the-insa-protein-of-is2 monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11503.jpg Conservation of Protein Domains Over Different Proteins Protein domains are small structurally independent units that are part of a single amino acid chain. Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms. A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form... https://www.jove.com/v/11503 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11505.jpg Intrinsically Disordered Proteins Intrinsically disordered proteins are a group of proteins that do not fold into specific three-dimensional structures. Their structural flexibility allows them to complement ordered proteins to perform functions that are inaccessible to rigid structures. They are more common in eukaryotes than prokaryotes and may either be exclusively intrinsically disordered or hybrid proteins, consisting of a mix of ordered and disordered regions. The absence of a rigid structure in these proteins can be... https://www.jove.com/v/11505 138 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11666.jpg Membrane Domains The membrane domains concentrate specific lipids and proteins at one place within the membrane, which helps in cell signaling, adhesion, and other critical cellular processes. These domains can differ in size, composition, function, and lifespan. Protein Domains The membrane comprises a group of distinct proteins responsible for carrying out a cell's specific function. For example, the plasma membrane of the human sperm, or a single germ cell, contains a unique set of proteins in the anterior... https://www.jove.com/v/11666 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11950.jpg Phosphoinositides and PIPs Phosphoinositides are a group of phospholipids containing a glycerol backbone with two fatty acid chains and a phosphate attached to a myoinositol sugar ring. The inositol head group extends into the cytoplasm, where it is modified by adding phosphate groups to form phosphatidylinositol phosphates or PIPs. Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane... https://www.jove.com/v/11950 102 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12552.jpg Mechanisms of Membrane Domain Formation Different physical properties of lipids and proteins allow them to localize and form distinct islands or domains in the membrane. Some membrane domains are formed due to protein-protein interactions, whereas others are formed due to the presence of specific lipids such as sphingolipids and sterols—for example, large proteins, such as bacteriorhodopsin, aggregate and create distinct domains. Another mechanism for membrane domain formation involves membrane proteins interacting with cytoskeletal... https://www.jove.com/v/12552 59 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13159.jpg Assembly of Signaling Complexes Multiprotein signaling complexes are formed in a dynamic process involving protein-protein interactions at the cytoplasmic domain of transmembrane receptors or enzymatic and non-enzymatic proteins associated with the receptor. These complexes ensure the activation and propagation of intracellular signals that regulate cell functions. Interaction domains in cell signaling Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,... https://www.jove.com/v/13159 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54466.jpg Single-molecule Super-resolution Imaging of Phosphatidylinositol 4,5-bisphosphate in the Plasma Membrane with Novel Fluorescent Probes PI(4,5)P2 regulates various cellular functions, but its nanoscale organization in the cell plasma membrane is poorly understood. By labeling PI(4,5)P2 with a dual-color fluorescent probe fused to the Pleckstrin Homology domain, we describe a novel approach to study the PI(4,5)P2 spatial distribution in the plasma membrane at the nanometer scale. https://www.jove.com/v/54466 446 2016-10-15T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58486.jpg Label-Free Imaging of Single Proteins Secreted from Living Cells via iSCAT Microscopy We present a protocol for the real-time optical detection of single unlabeled proteins as they are secreted from living cells. This is based on interferometric scattering (iSCAT) microscopy, which can be applied to a variety of different biological systems and configurations. https://www.jove.com/v/58486 655 2018-11-20T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59476.jpg Imaging Integrin Tension and Cellular Force at Submicron Resolution with an Integrative Tension Sensor Integrin tension plays important roles in various cell functions. With an integrative tension sensor, integrin tension is calibrated with picoNewton (pN) sensitivity and imaged at submicron resolution. https://www.jove.com/v/59476 440 2019-04-25T22:00:00+00:00 JoVE no https://visualize.jove.com/9358456-statistical-methods-in-functional-magnetic-resonance-imaging-with-respect-to-nonstationary-time-series-auditory-cortex-activity monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4262.jpg Mapping Cortical Dynamics Using Simultaneous MEG/EEG and Anatomically-constrained Minimum-norm Estimates: an Auditory Attention Example We use magneto- and electroencephalography (MEG/EEG), combined with anatomical information captured by magnetic resonance imaging (MRI), to map the dynamics of the cortical network associated with auditory attention. https://www.jove.com/v/4262 525 2012-10-24T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/4369.jpg Functional Magnetic Resonance Imaging (fMRI) with Auditory Stimulation in Songbirds This article shows an optimized procedure for imaging of the neural substrates of auditory stimulation in the songbird brain using functional Magnetic Resonance Imaging (fMRI). It describes the preparation of the sound stimuli, the positioning of the subject and the acquisition and subsequent analysis of the fMRI data. https://www.jove.com/v/4369 785 2013-06-03T15:56:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50872.jpg Functional Imaging of Auditory Cortex in Adult Cats using High-field fMRI Functional studies of the auditory system in mammals have traditionally been conducted using spatially-focused techniques such as electrophysiological recordings. The following protocol describes a method of visualizing large-scale patterns of evoked hemodynamic activity in the cat auditory cortex using functional magnetic resonance imaging. https://www.jove.com/v/50872 650 2014-02-19T22:30:00+00:00 JoVE no https://visualize.jove.com/9362499-the-transactivation-region-of-the-fis-protein-that-controls-site-specific-dna-inversion-contains-extended-mobile-beta-hairpin-arms monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11512.jpg Conserved Binding Sites Many proteins’ biological role depends on their interactions with their ligands, small molecules that bind to specific locations on the protein known as ligand-binding sites. Ligand-binding sites are often conserved among homologous proteins as these sites are critical for protein function. Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally analyses the... https://www.jove.com/v/11512 109 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11548.jpg The DNA Replication Fork An organism’s genome needs to be duplicated in an efficient and error-free manner for its growth and survival. The replication fork is a Y-shaped active region where two strands of DNA are separated and replicated continuously. The coupling of DNA unzipping and complementary strand synthesis is a characteristic feature of a replication fork. Organisms with small circular DNA, such as E. coli, often have a single origin of replication; therefore, they have only two replication forks, one in... https://www.jove.com/v/11548 62 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11551.jpg DNA Helicases DNA unwinding helicase enzymes are a type of motor protein. Motor proteins can translocate along filaments or polymers using energy generated from ATP hydrolysis. Helicases are involved in all the important cellular processes where DNA unwinding is required, such as DNA replication, repair, recombination, and transcription. They are present in all living organisms, but vary in their structure, function, and mechanism of action. For example, in prokaryotes, DnaB helicase binds and translocates... https://www.jove.com/v/11551 55 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11571.jpg DNA-only Transposons DNA-only transposons are called autonomous transposons since they code for the enzyme transposase that is required for the transposition mechanism. Insertion of transposons can alter gene functions in multiple ways. They can mutate the gene, alter gene expression by introducing a novel promoter or insulator sequence, introduce new splice sites, and change the mRNA transcripts produced, or remodel chromatin structure. The donor site from where the transposon is excised is either degraded or... https://www.jove.com/v/11571 177 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11613.jpg Eukaryotic Transcription Activators Transcription activators are proteins that promote the transcription of genes from DNA to RNA. In most cases, these proteins contain two separate domains ‒ a domain that binds to DNA and a domain for activating transcription; however, in some cases, a single domain is responsible for both binding and activation of transcription, as seen in the glucocorticoid receptor and MyoD. The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These domains are... https://www.jove.com/v/11613 162 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12223.jpg Single-Strand DNA Binding Proteins For successful DNA replication, the unwinding of double-stranded DNA must be accompanied by stabilization and protection of the separated single strands of the DNA. This crucial task is performed by single-strand DNA-binding (SSB) proteins. They bind to the DNA in a sequence-independent manner, which means that the nitrogenous bases of the DNA need not be present in a specific order for binding of SSB proteins to it. The binding of SSB proteins straightens single-stranded DNA (ssDNA) and makes... https://www.jove.com/v/12223 63 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58763.jpg High Sensitivity Measurement of Transcription Factor-DNA Binding Affinities by Competitive Titration Using Fluorescence Microscopy Here we present a novel method for determining binding affinities at equilibrium and in solution with high sensitivity on a large scale. This improves the quantitative analysis of transcription factor-DNA binding. The method is based on automated fluorescence anisotropy measurements in a controlled delivery system. https://www.jove.com/v/58763 398 2019-02-07T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62974.jpg Single-Molecule Imaging of EWS-FLI1 Condensates Assembling on DNA Here, we describe the use of the single-molecule imaging method, DNA Curtains, to study the biophysical mechanism of EWS-FLI1 condensates assembling on DNA. https://www.jove.com/v/62974 425 2021-09-08T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63147.jpg CD Spectroscopy to Study DNA-Protein Interactions The interaction of an ATP-dependent chromatin remodeler with a DNA ligand is described using CD spectroscopy. The induced conformational changes on a gene promoter analyzed by the peaks generated can be used to understand the mechanism of transcriptional regulation. https://www.jove.com/v/63147 408 2022-02-10T22:00:00+00:00 JoVE no https://visualize.jove.com/9394142-the-interest-checklist-a-factor-analysis monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11026.jpg Factorial Design Factorial Analysis is an experimental design that applies Analysis of Variance (ANOVA) statistical procedures to examine a change in a dependent variable due to more than one independent variable, also known as factors. Changes in worker productivity can be reasoned, for example, to be influenced by salary and other conditions, such as skill level. One way to test this hypothesis is by categorizing salary into three levels (low, moderate, and high) and skills sets into two levels (entry level... https://www.jove.com/v/11026 121 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13624.jpg Two-Way ANOVA The two-way ANOVA is an extension of the one-way ANOVA. It is a statistical test performed on three or more samples categorized by two factors - a row factor and a column factor. Ronald Fischer mentioned it in 1925 in his book 'Statistical Methods for Researchers.' The two-way ANOVA analysis initially begins by stating the null hypothesis that there is an interaction effect between the two factors of a dataset. This effect can be visualized using line segments formed by joining the means for... https://www.jove.com/v/13624 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14528.jpg Factors Affecting Activity Coefficient The extended Debye-Hückel equation indicates that the activity coefficient of an ion in an aqueous solution at 25°C depends on three partially interdependent properties: the ionic strength of the solution, the charge of the ion, and the ion size. The activity coefficient value for an ion is close to one when the solution has almost zero ionic strength, i.e., when the solution shows close to ideal behavior. As the ionic strength of the solution increases from 0 to 0.1 mol/L, a decrease in the... https://www.jove.com/v/14528 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18236.jpg Cattell's 16 Personality Factors Raymond Cattell's trait theory offers a structured framework for understanding personality by distinguishing between two critical traits: surface and source traits. Surface traits are observable patterns of behavior, such as indecisiveness, anxiety, and irrational fears. These traits are less stable, varying across situations and over time. This means that they are less helpful in understanding the deeper aspects of an individual's personality. In contrast, source traits are the fundamental,... https://www.jove.com/v/18236 84 JoVE no https://cloudfront.jove.com/files/ftp_upload/19951/19951_article_thumb_19951.jpg Factors Influencing Attraction III: Similarity The similarity hypothesis suggests that individuals are more likely to form relationships with others who share similar attitudes, beliefs, values, and interests. This concept has been widely studied in social psychology, demonstrating that perceived similarity fosters interpersonal attraction. In an experiment supporting this hypothesis, participants were presented with fabricated information indicating that strangers held attitudes similar to their own. The results showed that participants... https://www.jove.com/v/19951 83 2025-09-18T17:23:53+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19953/19953_article_thumb_19953.jpg Factors Influencing Attraction IV: Reciprocity Reciprocity in attraction is fundamental to social and romantic relationships, shaping how individuals form and maintain connections. The psychological principle underlying this phenomenon is that people tend to like those who express liking toward them. Balance theory supports this tendency, suggesting that mutual attraction fosters psychological harmony, whereas one-sided affection leads to discomfort and cognitive dissonance.The Psychological Mechanisms Behind ReciprocityWhen individuals... https://www.jove.com/v/19953 88 2025-09-18T17:23:52+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60035.jpg Applying an eMASS Customization Program as a Research Tool to Evaluate Consumer Benefits Presented here is a protocol to examine consumer responses toward mass customization in the context of online retailing. The protocol details the online survey procedure and how to analyze data using structural equation modeling and group differences using latent mean analyses. https://www.jove.com/v/60035 507 2019-09-27T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67031.jpg Advancing Dyslexia Assessment in Children Through Computerized Testing The Multimedia Battery for Assessment of General-Domain and Specific-Domain Skills in Reading is a reliable and valid multimedia battery designed to assess cognitive and basic reading skills. It enables the generation of a comprehensive cognitive and reading performance profile, which is particularly beneficial for children with dyslexia. https://www.jove.com/v/67031 540 2024-08-16T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68648.jpg Qualitative and Quantitative Validation of Tools with Rating Scales Aimed at Assessing the Quality of University Service-Learning This paper outlines the protocol for qualitatively and quantitatively validating a university service-learning instrument, following the parsimony criterion to create the most robust and optimal version possible. The Delphi qualitative validation method and Robust Unweighted Least Squares Exploratory Factor Analysis, as a quantitative item optimization method, are utilized for this purpose. https://www.jove.com/v/68648 639 2025-08-29T21:10:00+00:00 JoVE no https://visualize.jove.com/9394441-episodes-of-low-dimensional-self-organized-dynamics-from-electroencephalographic-alpha-signals monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2949.jpg Multi-electrode Array Recordings of Neuronal Avalanches in Organotypic Cultures A robust way to study neuronal avalanches, i.e. scale-invariant spatio-temporal activity bursts, indicative of critical state dynamics in cortex. Avalanches emerge spontaneously in developing superficial layers of cultured cortex which allows for long-term measurements of the activity with planar integrated multi-electrode arrays (MEA) under precisely controlled conditions. https://www.jove.com/v/2949 961 2011-08-01T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14942.jpg Brain Waves Brain waves are electrical signals generated by the neurons in the brain, which are regularly monitored to measure mental activities. Brain waves and their frequency ranges can be measured using an electroencephalogram or EEG. There are four main types of brain waves, each with distinct characteristics: • Alpha Waves – Alpha brain waves, between 8 and 13 Hz ( Hertz), occur when a person is relaxed with eyes closed. The alpha waves then disappear when one is concentrating on specific tasks. <br... https://www.jove.com/v/14942 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54746.jpg Network Analysis of Foramen Ovale Electrode Recordings in Drug-resistant Temporal Lobe Epilepsy Patients This protocol describes a procedure to track the evolution of mesial network measures in temporal lobe epilepsy (TLE) patients. It is based on the combination of intracranial recordings with a novel numerical technique for data analysis. Specifically, we present a protocol for network analyses of foramen ovale recordings. https://www.jove.com/v/54746 572 2016-12-18T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56452.jpg Microstate and Omega Complexity Analyses of the Resting-state Electroencephalography This article describes the protocol underlying electroencephalography (EEG) microstate analysis and omega complexity analysis, which are two reference-free EEG measures and highly valuable to explore the neural mechanisms of brain disorders. https://www.jove.com/v/56452 400 2018-06-15T19:30:00+00:00 JoVE no https://visualize.jove.com/9396209-integrins-their-structures-functions-and-gene-expressions-in-the-central-nervous-system-acta-anat monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11797.jpg Introduction to Actin Actin is a highly conserved cytoskeletal protein found abundantly in eukaryotic cells. It constitutes 10% weight of the total cellular protein in muscle cells, while in non-muscle cells, it is lower and makes up around 1–5 percent of the total cell protein. Actin found in the unicellular amoebae and complex multicellular animals is around 80% similar, demonstrating their conservation over a billion years of evolution. Actin coding genes are conserved within species and across different species. https://www.jove.com/v/11797 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13348.jpg Integrins Animal and protozoan cells do not have cell walls to help maintain shape and provide structural stability. Instead, these eukaryotic cells secrete a sticky mass of carbohydrates and proteins into the spaces between adjacent cells. This network of proteins and molecules is called an extracellular matrix or ECM. Some ECM proteins assemble into a basement membrane to which the remaining components adhere. Proteoglycans typically form the bulk of the ECM while fibrous proteins, like collagen,... https://www.jove.com/v/13348 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13349.jpg Activation of Integrins Integrins bind ligands and transmit information from outside the cell to inside or vice-versa through an "outside-in signaling" or "inside-out signaling." In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding events provide an effective stimulus. https://www.jove.com/v/13349 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13350.jpg Intracellular Signaling Affects Focal Adhesions Integrins act both as extracellular input receivers and as intracellular processing activators. As their name suggests, integrins are entirely integrated into the membrane structure. Their hydrophobic membrane-spanning regions interact with the phospholipid bilayer's hydrophobic region. These membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors. They activate intracellular response cascades when their effectors are bound and active. Some... https://www.jove.com/v/13350 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13355.jpg Catenins Catenins are characterized by multiple binding domains and dynamic structures that allow them to function as linker proteins in cell junction complexes. All catenins, except α-catenin, contain a characteristic protein sequence called the armadillo repeat and are therefore also called armadillo proteins. Catenins in Cell Junctions Catenins bind to cell adhesion molecules such as cadherins and link them to different cytoskeletal proteins depending on the type of cell junction. At the adherens... https://www.jove.com/v/13355 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14899.jpg Integration of Synaptic Events Synaptic integration mainly includes the summation of graded potentials. Graded potentials, regardless of their type, cause subtle alterations in membrane voltage, resulting in either depolarization or hyperpolarization. These incremental changes, when combined or summed, can propel the neuron toward its threshold. Consider, for example, a membrane experiencing a +15 mV shift, causing it to depolarize from -70 mV to -55 mV. In this scenario, graded potentials govern the membrane's ability to... https://www.jove.com/v/14899 88 2025-06-13T16:06:36+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55609.jpg Anatomically Inspired Three-dimensional Micro-tissue Engineered Neural Networks for Nervous System Reconstruction, Modulation, and Modeling This manuscript details the fabrication of micro-tissue engineered neural networks: three-dimensional micron-sized constructs comprised of long aligned axonal tracts spanning aggregated neuronal population(s) encased in a tubular hydrogel. These living scaffolds can serve as functional relays to reconstruct or modulate neural circuitry or as biofidelic test-beds mimicking gray-white matter neuroanatomy. https://www.jove.com/v/55609 645 2017-05-31T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56100.jpg The C. elegans Intestine As a Model for Intercellular Lumen Morphogenesis and In Vivo Polarized Membrane Biogenesis at the Single-cell Level: Labeling by Antibody Staining, RNAi Loss-of-function Analysis and Imaging The transparent C. elegans intestine can serve as an "in vivo tissue chamber" for studying apicobasal membrane and lumen biogenesis at the single-cell and subcellular level during multicellular tubulogenesis. This protocol describes how to combine standard labeling, loss-of-function genetic/RNAi and microscopic approaches to dissect these processes on a molecular level. https://www.jove.com/v/56100 735 2017-10-03T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57526.jpg Ex Utero Electroporation and Organotypic Slice Cultures of Embryonic Mouse Brains for Live-Imaging of Migrating GABAergic Interneurons Here, we provide a low-cost and reliable method to generate electroporated brain organotypic slice cultures from mouse embryos suitable for confocal microscopy and live-imaging techniques. https://www.jove.com/v/57526 590 2018-04-20T22:00:00+00:00 JoVE no https://visualize.jove.com/9424118-analysis-of-the-microbiological-information-derived-from-the-sentinel-laboratory-network-for-the-monitoring-of-the-human-immunodeficiency-virus-infection-in-catalonia-1989-1995 monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2312.jpg Comprehensive & Cost Effective Laboratory Monitoring of HIV/AIDS: an African Role Model Anti-retroviral therapy to treat HIV/AIDS is monitored in South Africa on a large scale. Flow cytometry is combined for haematology (CD45), immunology (CD4) and viral-load linked CD38 assay. Recorded at NHLS-SA laboratories, Johannesburg, these modern methods are cost-efficient with heightened local internal quality control, serving as role-models for resource-limited diagnostics. https://www.jove.com/v/2312 1436 2010-11-01T00:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/2820.jpg Cost-effective Method for Microbial Source Tracking Using Specific Human and Animal Viruses The study describes a cost-effective method for the identification of the source of fecal/urine contamination or contamination by nitrates in water using qPCR for the specific quantification of human/porcine/bovine DNA viruses, adenoviruses and polyomaviruses, proposed as MST tools. https://www.jove.com/v/2820 689 2011-12-03T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57013.jpg Ex Vivo Infection of Human Lymphoid Tissue and Female Genital Mucosa with Human Immunodeficiency Virus 1 and Histoculture Infection of human tissues with human immunodeficiency virus (HIV) ex vivo provides a valuable 3D model of virus pathogenesis. Here, we describe a protocol to process and infect tissue specimens from human tonsils and female genital mucosae with HIV-1 and maintain them in culture at the liquid-air interface. https://www.jove.com/v/57013 674 2018-10-12T20:00:00+00:00 JoVE no https://visualize.jove.com/9432746-anxiety-disorder-in-the-elderly-an-overview monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15206.jpg Anxiety: Overview Anxiety is a common mental disorder featuring excessive worry, fear, and apprehension, significantly affecting daily life. People with anxiety disorders experience persistent and intense anxiety, interrupting their everyday functioning. Individuals with anxiety often experience a range of physical and emotional symptoms, including sweating, trembling, tachycardia, and disturbances in sleep patterns. These symptoms vary in intensity and frequency but are generally disruptive and distressing.<br... https://www.jove.com/v/15206 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15207.jpg Anxiolytic Drugs: Overview Anxiolytic drugs are vital in managing anxiety disorders by effectively alleviating symptoms such as excessive fear, tachycardia, and tremors. There are several classes of anxiolytic medications, each with unique mechanisms of action and potential side effects. Primary Types of Anxiolytic Drugs 1. Benzodiazepines: Benzodiazepines bind to the GABA-A receptor in the brain, enhancing GABA's interaction. This action reduces neurotransmission, effectively blocking anxiety-associated limbic circuitry. https://www.jove.com/v/15207 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/17195/17195_article_thumb_17195.jpg Drug Dosing: Geriatric Patients Elderly individuals encompass a diverse population with varying degrees of age-related physiological changes. Defining the elderly presents challenges, as the geriatric population is often arbitrarily categorized as individuals older than 65. However, many individuals in this group lead active and healthy lives, with an increasing number surpassing 85 years and falling into the older elderly category. Physiological changes associated with aging impact performance capacity and homeostatic... https://www.jove.com/v/17195 75 2025-10-03T14:00:27+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17200/17200_article_thumb_17200.jpg Pharmacodynamics in Geriatric Patients: Effects of Age Age-related pharmacokinetic changes are extensively documented, but understanding age-related pharmacodynamic alterations is relatively limited. This knowledge gap can be partly attributed to the complexity of developing appropriate measures of drug responses compared to bioanalytical methods for determining drug concentrations.Most information regarding age-related differences in human pharmacodynamics originates from cross-sectional studies. However, these studies assume that observed mean... https://www.jove.com/v/17200 87 2025-10-03T14:00:04+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18603.jpg Generalized Anxiety Disorder Generalized Anxiety Disorder (GAD) is a chronic condition characterized by excessive and uncontrollable worry that persists for at least six months, significantly interfering with daily functioning. Unlike situational anxiety, which arises in response to specific stressors, GAD often occurs without a clear cause. Individuals may experience disproportionate worry about work, health, or relationships. For instance, a person might continuously fear poor health despite normal medical evaluations or... https://www.jove.com/v/18603 90 JoVE no https://cloudfront.jove.com/files/ftp_upload/40940/40940_article_thumb_40940.jpg Alzheimer Disease l: Introduction Alzheimer disease is a chronic, progressive, and irreversible neurodegenerative disorder and the most common cause of dementia in older adults. It leads to gradual neuronal loss, causing cognitive decline, behavioral changes, and loss of functional independence.Risk Factors and EtiologyThe disease is multifactorial. Age is the strongest risk factor, with prevalence doubling every 5 years after age 65. Genetic factors include mutations in genes such as APP, PSEN1, and PSEN2, which are associated... https://www.jove.com/v/40940 89 2026-04-15T17:31:37+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55727.jpg Reducing State Anxiety Using Working Memory Maintenance This protocol demonstrates how to measure anxiety-potentiated startle during the Sternberg Working Memory paradigm. https://www.jove.com/v/55727 497 2017-07-19T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59922.jpg Highlighting and Reducing the Impact of Negative Aging Stereotypes During Older Adults' Cognitive Testing Here, we present a protocol designed to show how negative aging stereotypes can impair memory performance of older adults during cognitive testing and how to reduce this deleterious effect. This method can help older people to perform at an optimal level during testing in both lab studies and clinical settings. https://www.jove.com/v/59922 418 2020-01-24T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/70026.jpg Therapeutic Massage for Psychological Well-being in Geriatric Oncology This study presents a therapeutic massage protocol to address psychological problems such as depression and anxiety in elderly cancer patients, aiming to support the integration of complementary therapies into comprehensive geriatric oncology care. https://www.jove.com/v/70026 239 2026-05-22T20:40:00+00:00 JoVE no https://visualize.jove.com/9433791-effects-of-idiosyncratic-stimulus-variables-on-functional-analysis-outcomes monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/51003.jpg A Method for Investigating Age-related Differences in the Functional Connectivity of Cognitive Control Networks Associated with Dimensional Change Card Sort Performance This video presents a method of examining age-related changes in functional connectivity of cognitive control networks engaged by targeted tasks/processes. The technique is based on multi-variate analysis of fMRI data. https://www.jove.com/v/51003 541 2014-05-07T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53466.jpg Combined Invasive Subcortical and Non-invasive Surface Neurophysiological Recordings for the Assessment of Cognitive and Emotional Functions in Humans The present protocol aims at assessing cognitive-emotional functions in the basal ganglia by simultaneous neurophysiological recording of local field potentials and non-invasive brain cortical activity (EEG). The procedure is exemplified by the use of paradigms involving speech stimuli with emotional connotation or the Flanker task involving cognitive control. https://www.jove.com/v/53466 505 2016-05-19T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58408.jpg A Two-interval Forced-choice Task for Multisensory Comparisons Psychophysics is essential for studying perception phenomena through sensory information. Here we present a protocol to perform a two-interval forced-choice task as implemented in a previous report on human psychophysics where participants estimated the duration of visual, auditory, or audiovisual intervals of aperiodic trains of pulses. https://www.jove.com/v/58408 433 2018-11-09T22:00:00+00:00 JoVE no https://visualize.jove.com/9465020-irregular-arrays-and-randomization monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12800.jpg Random Sampling Method Sampling is a technique to select a portion (or subset) of the larger population and study that portion (the sample) to gain information about the population. Data are the result of sampling from a population. The sampling method ensures that samples are drawn without bias and accurately represent the population. Because measuring the entire population in a study is not practical, researchers use samples to represent the population of interest. Among the various sampling methods used by... https://www.jove.com/v/12800 69 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13502.jpg Random and Systematic Errors Scientists always try their best to record measurements with the utmost accuracy and precision. However, sometimes errors do occur. These errors can be random or systematic. Random errors are observed due to the inconsistency or fluctuation in the measurement process, or variations in the quantity itself that is being measured. Such errors fluctuate from being greater than or less than the true value in repeated measurements. Consider a scientist measuring the length of an earthworm using a... https://www.jove.com/v/13502 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13571.jpg Random Variables A random variable is a single numerical value that indicates the outcome of a procedure. The concept of random variables is fundamental to the probability theory and was introduced by a Russian mathematician, Pafnuty Chebyshev, in the mid-nineteenth century. Uppercase letters such as X or Y denote a random variable. Lowercase letters like x or y denote the value of a random variable. If X is a random variable, then X is written in words, and x is given as a number. For example, let X = the... https://www.jove.com/v/13571 69 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13640.jpg Randomized Experiments The randomization process involves assigning study participants randomly to experimental or control groups based on their probability of being equally assigned. Randomization is meant to eliminate selection bias and balance known and unknown confounding factors so that the control group is similar to the treatment group as much as possible. A computer program and a random number generator can be used to assign participants to groups in a way that minimizes bias. Simple randomization Simple... https://www.jove.com/v/13640 73 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14508.jpg Random Error Random or indeterminate errors originate from various uncontrollable variables, such as variations in environmental conditions, instrument imperfections, or the inherent variability of the phenomena being measured. Usually, these errors cannot be predicted, estimated, or characterized because their direction and magnitude often vary in magnitude and direction even during consecutive measurements. As a result, they are difficult to eliminate. However, the aggregate effect of these errors can be... https://www.jove.com/v/14508 64 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13502.jpg Random and Systematic Errors Scientists always try their best to record measurements with the utmost accuracy and precision. However, sometimes errors do occur. These errors can be random or systematic. Random errors are observed due to the inconsistency or fluctuation in the measurement process, or variations in the quantity itself that is being measured. Such errors fluctuate from being greater than or less than the true value in repeated measurements. Consider a scientist measuring the length of an earthworm using a... https://www.jove.com/v/15561 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55548.jpg A Paired Bead and Magnet Array for Molding Microwells with Variable Concave Geometries This manuscript introduces a robust method of fabricating concave microwells without the need for complex high-cost facilities. Using magnetic force, steel beads, and a through-hole array, several hundred microwells were formed in a 3 cm x 3 cm polydimethylsiloxane (PDMS) substrate. https://www.jove.com/v/55548 702 2018-01-28T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59149.jpg Generating Strictly Controlled Stimuli for Figure Recognition Experiments This protocol describes a method for an experiment that examines whether specific graph and non-graph properties (features) are relevant to the recognition of figures. The method uses a database that stores various feature values of respective figures called (6 point, n line) figures. https://www.jove.com/v/59149 339 2019-03-18T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63131.jpg Patterning of Microorganisms and Microparticles through Sequential Capillarity-assisted Assembly We present a technology that uses capillarity-assisted assembly in a microfluidic platform to pattern micro-sized objects suspended in a liquid, such as bacteria and colloids, into prescribed arrays on a polydimethylsiloxane substrate. https://www.jove.com/v/63131 617 2021-11-04T20:00:00+00:00 JoVE no https://visualize.jove.com/9467253-the-comparison-of-usefulness-of-computer-tomography-and-angiography-in-diagnostics-of-intracranial-vascular-anomalies monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13864.jpg Computed Tomography Tomography refers to imaging by sections. Computed tomography (CT) is a non-invasive imaging technique that uses computers to analyze several cross-sectional X-rays to reveal minute details about structures in the body. The technique was invented in the 1970s and is based on the principle that as X-rays pass through the body, they are absorbed or reflected at different levels. In the technique, a patient lies on a motorized platform while a computerized axial tomography (CAT) scanner rotates... https://www.jove.com/v/13864 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16448.jpg Imaging Studies I: CT and MRI Introduction: MRI and CT scans are crucial advancements in medical imaging techniques, playing a vital role in diagnosing conditions related to the gastrointestinal (GI) system. Each scan serves distinct purposes, targets specific areas, and requires unique nursing duties. Description of the Procedures Computed Tomography (CT) scan: Computed Tomography (CT) scans use X-ray technology to generate detailed images of bones, organs, and tissues. During the scan, the patient lies on a moving table... https://www.jove.com/v/16448 74 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17752.jpg Brain Imaging Brain imaging technologies provide critical insights into both the structure and function of the human brain, enabling medical professionals and researchers to diagnose, study, and treat neurological disorders or psychiatric disorders more effectively. These technologies include computerized axial tomography (CAT or CT scans), positron-emission tomography (PET scans), magnetic resonance imaging (MRI), functional magnetic resonance imaging (fMRI), and Transcranial Magnetic Stimulation (TMS).<br... https://www.jove.com/v/17752 74 JoVE no https://cloudfront.jove.com/files/ftp_upload/17885/17885_article_thumb_17885.jpg Imaging Studies for Cardiovascular System V: CT Cardiac computed tomography (CT) scanning is an advanced cardiac imaging technique that utilizes CT technology, with or without intravenous (IV) contrast, to produce accurate cross-sectional virtual slices of specific areas of the heart, coronary circulation, and major blood vessels such as the aorta, pulmonary veins, and arteries. The computer processes these slices to generate three-dimensional images. Multidetector CT (MDCT) is a rapid form of CT scanning that captures multiple slices... https://www.jove.com/v/17885 88 2025-06-19T16:08:22+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18490/18490_article_thumb_18490.jpg Imaging Studies III: Computed Tomography DefinitionComputed Tomography (CT) of the genitourinary (GU) tract is a non-invasive imaging modality that utilizes X-rays and computer processing to generate detailed cross-sectional images of the urinary system, encompassing the kidneys, ureters, bladder, and adjacent structures such as the adrenal glands.PurposeCT scans of the GU tract serve several diagnostic and therapeutic purposes, including:Diagnosis of Urinary Tract Diseases: Detects kidney stones, tumors, cysts, and congenital... https://www.jove.com/v/18490 87 2025-06-19T16:29:40+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18494/18494_article_thumb_18494.jpg Imaging Studies VII: Vascular Imaging DefinitionRenal angiography, also known as renal arteriography, is an imaging technique used to obtain a comprehensive view of blood flow and the vascular structure of blood vessels in the kidneys and surrounding areas.PurposeRenal angiography detects blood vessel abnormalities in the kidneys, such as aneurysms, stenosis, thrombosis, vascular tumors, and renal artery stenosis. It evaluates kidney function and guides interventional treatments like angioplasty or stent placement.Pre-Procedure... https://www.jove.com/v/18494 79 2025-06-19T16:30:31+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53459.jpg Computed Tomography and Optical Imaging of Osteogenesis-angiogenesis Coupling to Assess Integration of Cranial Bone Autografts and Allografts Implantation of autologous and allogeneic bone grafts constitute accepted approaches to treat major craniofacial bone loss. Yet the effect of graft composition on the interplay among neovascularization, cell differentiation and bone formation is unclear. We present a multimodal imaging protocol aimed to elucidate the angiogenesis-osteogenesis interdependence at the graft proximity. https://www.jove.com/v/53459 796 2015-12-22T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56397.jpg Optimized Management of Endovascular Treatment for Acute Ischemic Stroke The outcome of patients with acute ischemic stroke depends on swift restoration of cerebral blood flow. This protocol aims at optimizing the management of such patients by minimizing peri-procedural timings and rendering the time from hospital admission to reperfusion as short as possible. https://www.jove.com/v/56397 561 2018-01-18T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62958.jpg Time-Resolved, Dynamic Computed Tomography Angiography for Characterization of Aortic Endoleaks and Treatment Guidance via 2D-3D Fusion-Imaging Dynamic computed tomography angiography (CTA) imaging provides additional diagnostic value in characterizing aortic endoleaks. This protocol describes a qualitative and quantitative approach using time-attenuation curve analysis to characterize endoleaks. The technique of integrating dynamic CTA imaging with fluoroscopy using 2D-3D image fusion is illustrated for better image guidance during treatment. https://www.jove.com/v/62958 572 2021-12-09T21:00:00+00:00 JoVE no https://visualize.jove.com/9473995-recognition-of-daily-life-motor-activity-classes-using-an-artificial-neural-network monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/53004.jpg Evaluation of a Smartphone-based Human Activity Recognition System in a Daily Living Environment A standardized evaluation method was developed for Wearable Mobility Monitoring Systems (WMMS) that includes continuous activities in a realistic daily living environment. Testing with a series of daily living activities can decrease activity recognition sensitivity; therefore, realistic testing circuits are encouraged for valid evaluation of WMMS performance. https://www.jove.com/v/53004 409 2015-12-11T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59827.jpg Dynamic Digital Biomarkers of Motor and Cognitive Function in Parkinson's Disease This protocol offers a digitization of portions of traditional clinical tasks commonly used to measure cognition and motor control in Parkinson’s disease. Clinical tasks are digitized while biophysical rhythms are co-registered from different functional levels of the nervous systems, ranging from voluntary, spontaneous, automatic to autonomic. https://www.jove.com/v/59827 628 2019-07-24T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65931.jpg Artificial Intelligence-Based System for Detecting Attention Levels in Students This paper proposes an artificial intelligence-based system to automatically detect whether students are paying attention to the class or are distracted. This system is designed to help teachers maintain students' attention, optimize their lessons, and dynamically introduce modifications in order for them to be more engaging. https://www.jove.com/v/65931 397 2023-12-15T22:10:00+00:00 JoVE no https://visualize.jove.com/9517994-profile-of-central-nervous-system-pathology-in-patients-with-aids-an-autopsy-study-from-india monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15204.jpg Alzheimer's Disease: Overview Alzheimer's Disease (AD) is a continually advancing neurodegenerative disorder, distinguished by escalating memory loss, cognitive dysfunction, and dementia. The disease unfolds in three stages: preclinical, mild cognitive impairment (MCI), and dementia. Its onset is insidious, and the progression gradual, with the cause not well explained by other disorders. The clinical diagnosis of AD hinges on the presence of memory and other cognitive impairments. Biomarkers, such as changes in Aβ and tau... https://www.jove.com/v/15204 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/40851/40851_article_thumb_40851.jpg Cryptococcal Meningitis Cryptococcal meningitis is a life-threatening opportunistic infection predominantly associated with HIV/AIDS, accounting for over 100,000 deaths annually worldwide. However, it also affects individuals with other forms of immunosuppression, including those undergoing immunosuppressive therapy, organ transplant recipients, patients with innate immunodeficiencies, and individuals with hematological disorders. The infection is caused mainly by Cryptococcus neoformans and Cryptococcus gattii,... https://www.jove.com/v/40851 87 2026-05-20T21:22:09+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40924/40924_article_thumb_40924.jpg Encephalitis ll: Pathophysiology Encephalitis is inflammation of the brain parenchyma caused by direct viral invasion or immune-mediated mechanisms triggered by infections or tumors. Both processes lead to neuronal injury, disrupted neurotransmission, and diverse neurological symptoms, often with overlapping clinical and pathological features.Autoimmune EncephalitisIn autoimmune encephalitis, antibodies target neuronal antigens on cell surfaces, synapses, or within neurons. A key example is anti-NMDAR encephalitis, which can... https://www.jove.com/v/40924 86 2026-05-14T20:00:51+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40940/40940_article_thumb_40940.jpg Alzheimer Disease l: Introduction Alzheimer disease is a chronic, progressive, and irreversible neurodegenerative disorder and the most common cause of dementia in older adults. It leads to gradual neuronal loss, causing cognitive decline, behavioral changes, and loss of functional independence.Risk Factors and EtiologyThe disease is multifactorial. Age is the strongest risk factor, with prevalence doubling every 5 years after age 65. Genetic factors include mutations in genes such as APP, PSEN1, and PSEN2, which are associated... https://www.jove.com/v/40940 89 2026-04-15T17:31:37+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40941/40941_article_thumb_40941.jpg Alzheimer Disease ll: Pathophysiology Alzheimer disease involves structural changes in the brain that begin long before symptoms appear. The most distinctive features are extracellular neuritic plaques and intracellular neurofibrillary tangles.Neuritic plaques form in the cerebral cortex and around blood vessels. These plaques contain a dense core of beta-amyloid (Aβ)—a toxic protein fragment that clumps outside neurons. The core is surrounded by damaged neuronal extensions, as well as reactive astrocytes and microglia. Abnormal... https://www.jove.com/v/40941 83 2026-04-13T21:37:54+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40943/40943_article_thumb_40943.jpg Parkinson Disease ll: Pathophysiology Parkinson disease (PD) is a progressive neurodegenerative disorder primarily affecting movement, with additional non-motor features. Its pathophysiology involves complex interactions among genetic susceptibility, environmental exposures, and cellular dysfunction, including dopaminergic neuron loss, protein aggregation, and mitochondrial impairment.Selective NeurodegenerationA key feature is the degeneration of dopaminergic neurons in the substantia nigra pars compacta, leading to reduced... https://www.jove.com/v/40943 84 2026-04-15T17:34:54+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54602.jpg Symmetric Bihemispheric Postmortem Brain Cutting to Study Healthy and Pathological Brain Conditions in Humans Organized brain cutting procedures are necessary to correlate specific neuropsychiatric phenomena with definitive neuropathologic diagnoses. Brain cuttings are performed differently based on various clinico-academic contingencies. This protocol describes a symmetric bihemispheric brain cutting procedure to investigate hemispheric differences in human brain pathologies and to maximize current and future biomolecular/neuroimaging techniques. https://www.jove.com/v/54602 509 2016-12-18T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59511.jpg Comprehensive Autopsy Program for Individuals with Multiple Sclerosis Multiple sclerosis is an inflammatory demyelinating disease with no cure. Analysis of brain tissue provides important clues to understanding the pathogenesis of the disease. Here we discuss the methodology and downstream analysis of MS brain tissue collected through a unique rapid autopsy program in operation at the Cleveland Clinic. https://www.jove.com/v/59511 581 2019-07-19T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60296.jpg Abbiategrasso Brain Bank Protocol for Collecting, Processing and Characterizing Aging Brains This protocol describes a method to track individual brain-aging trajectories through a brain donation program and proper characterization of brains. Brain donors are involved in a long-term longitudinal study including serial multi-dimensional assessments. The protocol contains a detailed description of brain processing and an accurate diagnostic methodology. https://www.jove.com/v/60296 748 2020-06-03T20:00:00+00:00 JoVE no https://visualize.jove.com/9560401-evidence-for-a-multistep-control-in-transposition-of-i-factor-in-drosophila-melanogaster monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3395.jpg Quantitative Comparison of cis -Regulatory Element (CRE) Activities in Transgenic Drosophila melanogaster Phenotypic variation for traits can result from mutations in cis-regulatory element (CRE) sequences that control gene expression patterns. Methods derived for use in Drosophila melanogaster can quantitatively compare the levels of spatial and temporal patterns of gene expression mediated by modified or naturally occurring CRE variants. https://www.jove.com/v/3395 499 2011-12-19T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11536.jpg Position-effect Variegation In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.<br... https://www.jove.com/v/11536 152 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11570.jpg Overview of Transposition and Recombination Transposons make up a significant part of genomes of various organisms. Therefore, it is believed that transposition played a major evolutionary role in speciation by changing genome sizes and modifying gene expression patterns. For example, in bacteria, transposition can lead to conferring antibiotic resistance. Movement of transposable elements within the genetic pool of pathogenic bacteria can aid in transfer of antibiotic-resistant genetic elements. In eukaryotes, transposons can carry out... https://www.jove.com/v/11570 133 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11607.jpg Cis-regulatory Sequences Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are... https://www.jove.com/v/11607 122 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11615.jpg Combinatorial Gene Control Combinatorial gene control is the synergistic action of several transcriptional factors to regulate the expression of a single gene. The absence of one or more of these factors may lead to a significant difference in the level of gene expression or repression. The expression of more than 30,000 genes is controlled by approximately 2000-3000 transcription factors. This is possible because a single transcription factor can recognize more than one regulatory sequence. The specificity in gene... https://www.jove.com/v/11615 153 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11980.jpg The Ratio of X Chromosome to Autosomes In most organisms, sex is determined by the ratio of X and Y chromosomes. However, in some organisms, such as Drosophila and C.elegans, sex is determined by the ratio of the number of X chromosomes to the number of sets of autosomes. The Y chromosome in Drosophila is active but does not determine sex. It contains genes responsible for the production of sperms in adult flies. Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila... https://www.jove.com/v/11980 165 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60282.jpg Imaging and Analysis of Tissue Orientation and Growth Dynamics in the Developing Drosophila Epithelia During Pupal Stages This protocol is designed for the imaging and analysis of the dynamics of cell orientation and tissue growth in the Drosophila abdominal epithelia as the fruit fly undergoes metamorphosis. The methodology described here can be applied to the study of different developmental stages, tissues, and subcellular structures in Drosophila or other model organisms. https://www.jove.com/v/60282 505 2020-06-02T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66679.jpg Embryo Microinjection for Transgenesis in Drosophila This article takes the phiC31 integrase-mediated transgenesis in Drosophila as an example and presents an optimized protocol for embryo microinjection, a crucial step for creating transgenic flies. https://www.jove.com/v/66679 332 2024-06-07T21:10:00+00:00 JoVE no https://visualize.jove.com/9592172-multiple-domains-for-initiator-binding-proteins-tfii-i-and-yy-1-are-present-in-the-initiator-and-upstream-regions-of-the-rat-xdhxo-tata-less-promoter monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4110.jpg High-throughput Purification of Affinity-tagged Recombinant Proteins We describe a method for the affinity-tagged purification of recombinant proteins using liquid-handling robotics. This method is generally applicable to the small-scale purification of soluble His-tagged proteins in a high-throughput format. https://www.jove.com/v/4110 464 2012-08-26T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10983.jpg Transcription Factors Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of... https://www.jove.com/v/10983 136 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11611.jpg The Eukaryotic Promoter Region The eukaryotic promoter region is a segment of DNA located upstream of a gene. It contains an RNA polymerase binding site, a transcription start site, and several cis-regulatory sequences. The proximal promoter region is located in the vicinity of the gene and has cis-regulatory sequences and the core promoter. The core promoter is the binding site for RNA polymerase and is usually located between -35 and +35 nucleotides from the transcription start site. The distal promoter regions are... https://www.jove.com/v/11611 160 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11613.jpg Eukaryotic Transcription Activators Transcription activators are proteins that promote the transcription of genes from DNA to RNA. In most cases, these proteins contain two separate domains ‒ a domain that binds to DNA and a domain for activating transcription; however, in some cases, a single domain is responsible for both binding and activation of transcription, as seen in the glucocorticoid receptor and MyoD. The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These domains are... https://www.jove.com/v/11613 162 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12225.jpg Transcription Initiation Initiation is the first step of transcription in eukaryotes. Prokaryotic RNA Polymerase (RNAP) can bind to the template DNA and start transcribing. On the other hand, transcription in eukaryotes requires additional proteins, called transcription factors, to first bind to the promoter region in the DNA template. This binding helps recruit the specific RNAP that can assemble on the DNA and start transcription. The promoters and enhancers and their accessory proteins allow tight regulation of... https://www.jove.com/v/12225 107 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12561.jpg General Transcription Factors Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of... https://www.jove.com/v/12561 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11611.jpg The Eukaryotic Promoter Region The eukaryotic promoter region is a segment of DNA located upstream of a gene. It contains an RNA polymerase binding site, a transcription start site, and several cis-regulatory sequences. The proximal promoter region is located in the vicinity of the gene and has cis-regulatory sequences and the core promoter. The core promoter is the binding site for RNA polymerase and is usually located between -35 and +35 nucleotides from the transcription start site. The distal promoter regions are... https://www.jove.com/v/13146 160 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57320.jpg Promoter Capture Hi-C: High-resolution, Genome-wide Profiling of Promoter Interactions DNA regulatory elements, such as enhancers, control gene expression by physically contacting target gene promoters, often through long-range chromosomal interactions spanning large genomic distances. Promoter Capture Hi-C (PCHi-C) identifies significant interactions between promoters and distal regions, enabling the assignment of potential regulatory sequences to their target genes. https://www.jove.com/v/57320 616 2018-06-28T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59192.jpg Enhanced Yeast One-hybrid Screens To Identify Transcription Factor Binding To Human DNA Sequences Here, we present an enhanced yeast one-hybrid screening protocol to identify the transcription factors (TFs) that can bind to a human DNA region of interest. This method uses a high-throughput screening pipeline that can interrogate the binding of >1,000 TFs in a single experiment. https://www.jove.com/v/59192 685 2019-02-11T23:00:00+00:00 JoVE no https://visualize.jove.com/9594574-autoregulation-of-eukaryotic-transcription-factors monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10983.jpg Transcription Factors Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of... https://www.jove.com/v/10983 136 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10983.jpg Transcription Factors Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of... https://www.jove.com/v/11582 136 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11584.jpg RNA Polymerase II Accessory Proteins Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in... https://www.jove.com/v/11584 156 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11612.jpg Co-activators and Co-repressors Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into... https://www.jove.com/v/11612 124 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12561.jpg General Transcription Factors Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of... https://www.jove.com/v/12561 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11612.jpg Co-activators and Co-repressors Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into... https://www.jove.com/v/13147 124 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53300.jpg Describing a Transcription Factor Dependent Regulation of the MicroRNA Transcriptome Herein we propose a strategy to study the effect of a transcription factor of interest on the microRNA transcriptome using publically available data, computational resources and high throughput data from microRNA arrays after transfecting cells with small hairpin (sh)RNA targeting a transcription factor of interest. https://www.jove.com/v/53300 443 2016-06-15T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56752.jpg Real-time Analysis of Transcription Factor Binding, Transcription, Translation, and Turnover to Display Global Events During Cellular Activation This protocol describes the combinatorial use of ChIP-seq, 4sU-seq, total RNA-seq, and ribosome profiling for cell lines and primary cells. It enables tracking changes in transcription-factor binding, de novo transcription, RNA processing, turnover and translation over time, and displaying the overall course of events in activated and/or rapidly changing cells. https://www.jove.com/v/56752 774 2018-03-07T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62974.jpg Single-Molecule Imaging of EWS-FLI1 Condensates Assembling on DNA Here, we describe the use of the single-molecule imaging method, DNA Curtains, to study the biophysical mechanism of EWS-FLI1 condensates assembling on DNA. https://www.jove.com/v/62974 425 2021-09-08T22:00:00+00:00 JoVE no https://visualize.jove.com/9641367-an-all-comers-policy-for-ruptured-abdominal-aortic-aneurysms-how-can-results-be-improved monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17903/17903_article_thumb_17903.jpg Aortic Regurgitation I: Introduction IntroductionAortic regurgitation is characterized by the backward flow of blood from the aorta into the left ventricle during diastole and arises from the improper closure of the aortic valve. This condition results in left ventricular volume overload and can stem from both acute and chronic etiologies, each contributing uniquely to the disease's progression and symptomatology.Acute and Chronic CausesAcute aortic regurgitation often results from events that suddenly impair the integrity of the... https://app.jove.com/v/17903 75 1600 2025-06-19T01:20:10+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17905/17905_article_thumb_17905.jpg Aortic Regurgitation III: Medical Management Aortic regurgitation (AR) is when the aortic valve does not close or seal properly, leading to backward blood circulation from the aorta into the left ventricle during diastole. Common causes of AR include rheumatic heart disease, congenital valve defects, and aortic root dilation. Managing AR requires a multifaceted approach to alleviate symptoms, preserve left ventricular function, and address the underlying cause of the regurgitation. Patients with symptomatic AR or significant left... https://app.jove.com/v/17905 85 581 2025-06-19T01:20:54+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17979/17979_article_thumb_17979.jpg Aneurysm I: Introduction An aortic aneurysm is a localized outpouching or dilation at a weak point in the artery wall. It may involve different parts of the aorta, such as the abdominal aorta, aortic arch, or thoracic aorta.Etiological factorsSeveral disorders are associated with aortic aneurysms.Congenital causes, such as primary connective tissue disorders like Marfan syndrome, impact the integrity and strength of connective tissues, notably affecting the aorta. Marfan syndrome is a genetic disorder that specifically... https://app.jove.com/v/17979 90 646 2025-06-19T01:19:01+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17980/17980_article_thumb_17980.jpg Aneurysm II: Clinical Manifestations and Diagnostic Studies Thoracic, aortic arch and abdominal aneurysms are significant vascular conditions that can present with various clinical manifestations and lead to serious complications. Understanding these manifestations and the appropriate diagnostic studies is essential for effective management and treatment.Thoracic Aortic AneurysmsThoracic aortic aneurysms often remain asymptomatic until they reach a size that impinges on adjacent structures. They typically cause deep, diffuse chest pain that radiates to... https://app.jove.com/v/17980 81 581 2025-06-19T01:19:14+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17981/17981_article_thumb_17981.jpg Aneurysm III: Interprofessional Care Aneurysm management involves either conservative medical therapy or surgical intervention, depending on the size and symptoms of the aneurysm. Conservative management is generally reserved for smaller, asymptomatic aneurysms, while larger or symptomatic aneurysms often necessitate surgical repair.Conservative Medical TherapyFor small, asymptomatic aneurysms, particularly abdominal aortic aneurysms (AAA) less than 5.5 centimeters in diameter, conservative medical therapy is recommended. This... https://app.jove.com/v/17981 86 477 2025-06-19T01:19:25+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17982/17982_article_thumb_17982.jpg Aneurysm IV: Nursing Management Vigilant monitoring for aneurysm rupture is essential for patients undergoing aortic surgery.Preoperative Nursing ManagementContinuously monitor the patient for manifestations of aneurysm rupture, such as pallor, weakness, tachycardia, hypotension, abdominal, back, groin, or periumbilical pain, changes in consciousness, and a pulsating abdominal mass. Regularly assess the patient's peripheral pulses.Instruct the patient to consume a clear liquid diet the day before surgery and administer... https://app.jove.com/v/17982 82 618 2025-06-19T01:19:35+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57984.jpg Manufacturing Abdominal Aorta Hydrogel Tissue-Mimicking Phantoms for Ultrasound Elastography Validation Here we describe a method to manufacture aneurysmal, aortic tissue-mimicking phantoms for the use in testing ultrasound elastography. The combined use of computer-aided design (CAD) and 3-dimensional (3D) printing techniques produce aortic phantoms with predictable, complex geometries to validate the elastographic imaging algorithms with controlled... https://app.jove.com/v/57984 572 17700 2018-09-19T05:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65487.jpg Author Spotlight: Using Point-of-Care Ultrasound for Comprehensive Evaluation of the Abdominal Aorta This protocol reviews the steps to image the abdominal aorta with point-of-care ultrasound. We discuss image acquisition, troubleshooting imaging pitfalls and artifacts, and the recognition of life-threatening abdominal aortic... https://app.jove.com/v/65487 432 5100 2023-09-08T05:40:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68211.jpg Modified Octopus Technique for Thoracoabdominal Aortic Aneurysm This study describes a modified octopus technique for endovascular treatment of thoracoabdominal aortic aneurysms, demonstrating favorable clinical... https://app.jove.com/v/68211 296 645 2025-08-01T04:50:00+00:00 JoVE no https://visualize.jove.com/9651895-assessment-of-alternating-air-mattresses-using-a-time-based-interface-pressure-threshold-technique monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4315.jpg Tilt Testing with Combined Lower Body Negative Pressure: a "Gold Standard" for Measuring Orthostatic Tolerance We describe a "gold standard" for evaluating orthostatic tolerance (OT) using tilt testing with combined lower body negative pressure (LBNP). This can be combined with non-invasive evaluations of cardiovascular reflex control. Normal and abnormal responses are defined. https://www.jove.com/v/4315 849 2013-03-21T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13299.jpg Assessment of Ventilation I: Respiratory Rate Assessment of Ventilation A Ventilation assessment is critical for monitoring a patient's health status. Respiration, one of the most accessible vital signs, provides insights into the function of numerous body systems and can indicate serious health issues, such as brainstem injuries from head trauma. Critical Guidelines for Assessing Ventilation: Unobtrusive Observation: Maintaining accuracy in ventilation assessment is paramount. Observing the patient's breathing without their knowledge is... https://www.jove.com/v/13299 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13310.jpg Sites for measuring blood pressure Blood pressure measurement is a fundamental clinical procedure, providing crucial data for assessing cardiovascular health. Among the various sites for this measurement, the brachial and popliteal arteries are predominantly utilized due to their accessibility and the reliability of their readings. This lesson delves into the anatomical significance, methodology, and considerations of measuring blood pressure at these locations. The Brachial Artery: Primary Site for Blood Pressure Measurement<br... https://www.jove.com/v/13310 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13311.jpg Equipments Used To Measure Blood Pressure Direct Method This invasive approach involves cannulating a peripheral artery. During each cardiac contraction, pressure generates mechanical motion within the catheter, transmitted through rigid, fluid-filled tubing to a transducer. This transducer converts mechanical motion into electrical signals displayed as waveforms on a monitor. An automatic flushing system prevents blood backflow. Due to the potential risk of unexpected arterial blood loss, this method is primarily used in intensive... https://www.jove.com/v/13311 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13315.jpg Assessment of blood pressure in brachial artery(two-step method) Measuring blood pressure is a fundamental skill in healthcare that aids in diagnosing and monitoring hypertension and other cardiovascular conditions. An aneroid sphygmomanometer, commonly used in clinical settings, offers a manual and precise method for blood pressure measurement. The technique for using this instrument involves specific steps that must be carefully executed to ensure accuracy. The following detailed description outlines a two-step technique for assessing blood pressure using... https://www.jove.com/v/13315 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13837.jpg Assessment of Ventilation II: Respiratory Depth and Rhythm Respiratory Depth Respiratory depth measures the volume of air inhaled or exhaled during a breath. It can vary from shallow to deep and typically remains consistent when a person is at rest or asleep. Occasionally, individuals will automatically inhale deeply, known as sighing, which inflates the lungs with more air than normal breathing. To assess respiratory depth, observe the degree of chest excursion or movement: • Deep Respiration: Involves full lung expansion and complete exhalation,... https://www.jove.com/v/13837 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16400.jpg Mechanical Ventilation III: Noninvasive Ventilation Noninvasive positive-pressure ventilation (NIPPV), continuous positive airway pressure (CPAP), and bilevel positive airway pressure (BiPAP) are essential methods in respiratory care. These ventilation techniques offer unique benefits for patients with various respiratory conditions, providing adequate support without requiring intubation. Let's explore how each method is crucial in improving patient outcomes and enhancing respiratory therapy. Noninvasive Positive-Pressure Ventilation (NIPPV)<br... https://www.jove.com/v/16400 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50178.jpg Evaluation of Respiratory Muscle Activation Using Respiratory Motor Control Assessment (RMCA) in Individuals with Chronic Spinal Cord Injury The purpose of this publication is to present our original work on a multi-muscle surface electromyographic approach to quantitatively characterize respiratory muscle activation patterns in individuals with chronic spinal cord injury using vector-based analysis. https://www.jove.com/v/50178 577 2013-07-19T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51082.jpg Assessing Cerebral Autoregulation via Oscillatory Lower Body Negative Pressure and Projection Pursuit Regression Cerebral perfusion is maintained across a range of pressures via cerebral autoregulation. However, characterizing autoregulation requires prominent pressure fluctuations at regulated frequencies. The described protocol will show how oscillatory lower body negative pressure can generate pressure fluctuations to provide data for projection pursuit regression for quantification of the autoregulatory curve. https://www.jove.com/v/51082 686 2014-12-10T21:00:00+00:00 JoVE no https://visualize.jove.com/9678285-relation-between-severity-of-coronary-artery-disease-left-ventricular-function-and-myocardial-infarction-and-influence-of-the-ace-id-gene-polymorphism monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17923/17923_article_thumb_17923.jpg Coronary Artery Disease I: Introduction Coronary Artery Disease (CAD): An Overview with Scientific InsightsCoronary Artery Disease (CAD), often referred to as C-A-D, is a prevalent blood vessel disorder classified under the broader category of atherosclerosis. Atherosclerosis is a pathological process characterized by the hardening and narrowing of arteries due to the accumulation of atherosclerotic plaques. These plaques are composed of cholesterol, fatty substances, inflammatory cells, calcium, and fibrin, reducing blood flow to... https://www.jove.com/v/17923 90 2025-06-19T16:26:55+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17924/17924_article_thumb_17924.jpg Coronary Artery Disease II: Pathophysiology Coronary Artery Disease (CAD) originates from a series of events that impair the function of coronary arteries, the blood vessels responsible for delivering oxygen-rich blood to the heart muscle. The pathophysiology of CAD is closely linked to atherosclerosis, a chronic inflammatory and lipid-driven condition affecting the vascular endothelium.1. Endothelial DamageThe process begins with damage to the vascular endothelium, which serves as a protective barrier between the blood and the vessel... https://www.jove.com/v/17924 86 2025-06-19T16:27:14+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17925/17925_article_thumb_17925.jpg Coronary Artery Disease III: Clinical Manifestations Coronary Artery Disease (CAD) is a primary health risk worldwide, leading to significant morbidity and mortality. The condition arises from the buildup of atherosclerotic plaques within the coronary arteries, resulting in diminished blood supply to the heart muscle.The clinical manifestations of CAD vary widely, from asymptomatic stages to severe, life-threatening conditions. Understanding these manifestations is crucial for early diagnosis and effective management.Angina Pectoris: The Warning... https://www.jove.com/v/17925 90 2025-06-19T16:27:32+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17929/17929_article_thumb_17929.jpg Acute Coronary Syndrome II: Pathophysiology and Clinical Manifestations The pathophysiology of Acute Coronary Syndrome [ACD] involves several key processes:The main underlying cause of ACD is atherosclerosis, a chronic inflammatory disease characterized by the buildup of lipid-laden plaques within the coronary arteries.As the atherosclerotic plaque grows in the coronary artery, it may become unstable due to the formation of a lipid-rich core and a thin fibrous cap. Inflammatory cells within the plaque, such as macrophages, secrete enzymes that degrade the... https://www.jove.com/v/17929 79 2025-06-19T15:07:26+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17930/17930_article_thumb_17930.jpg Acute Coronary Syndrome III: Diagnostic Studies Diagnosing acute coronary syndrome or ACS begins with a thorough patient history. Notable symptoms include central, crushing chest pain radiating to the left arm, neck, jaw, or back, along with shortness of breath, sweating (diaphoresis), nausea, vomiting, dizziness, and palpitations.It is crucial to note any history of cardiac illnesses and assess risk factors, including age, gender, smoking, hypertension, diabetes, hyperlipidemia, and a sedentary lifestyle.During physical examination, vital... https://www.jove.com/v/17930 90 2025-06-19T15:08:40+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17960/17960_article_thumb_17960.jpg Cardiomyopathy III: Hypertrophic Cardiomyopathy Hypertrophic cardiomyopathy, or HCM, is an autosomal dominant genetic disorder characterized by asymmetric left ventricular hypertrophy without ventricular dilation. It is more common in men and is typically diagnosed in young, athletic adults.EtiologyHCM is primarily genetic and is caused by mutations in genes encoding sarcomeric proteins. Researchers have identified over 1400 mutations across at least 11 different genes. Among these, the most frequently occurring mutations are found in the... https://www.jove.com/v/17960 89 2025-08-11T17:09:32+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57950.jpg Digital PCR for Quantifying Circulating MicroRNAs in Acute Myocardial Infarction and Cardiovascular Disease Circulating microRNAs have shown promise as biomarkers for cardiovascular diseases and acute myocardial infarctions. In this study, we describe a protocol for miRNA extraction, reverse transcription, and digital PCR for the absolute quantification of miRNAs in the serum of patients with cardiovascular disease. https://www.jove.com/v/57950 281 2018-07-03T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61901.jpg Post-Myocardial Infarction Heart Failure in Closed-chest Coronary Occlusion/Reperfusion Model in Göttingen Minipigs and Landrace Pigs The overall goal of the current study is to present the techniques of induction of myocardial infarction (MI) and post-myocardial infarction heart failure (post-MI HF) in closed-chest, adult Göttingen minipigs and the characterization of post-MI HF model in Göttingen minipigs as compared to Landrace pigs. https://www.jove.com/v/61901 875 2021-04-17T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63508.jpg Generation and Characterization of Right Ventricular Myocardial Infarction Induced by Permanent Ligation of the Right Coronary Artery in Mice There are several differences between the right and left ventricles. However, the pathophysiology of right ventricular infarction (RVI) has not been clarified. In the present protocol, a reproducible method for RVI mouse model generation is introduced, which may provide a means to explain the mechanism of RVI. https://www.jove.com/v/63508 618 2022-02-01T22:50:00+00:00 JoVE no https://visualize.jove.com/9694575-adrenocortical-cells-are-the-site-of-secretion-and-action-of-insulin-like-growth-factors-and-tnf-alpha monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14467.jpg Adrenergic Receptors: β Subtype β-adrenoceptors have varied sensitivities towards adrenaline, noradrenaline, and isoprenaline. The order of agonist potency is as follows: Isoprenaline > Adrenaline > Noradrenaline Neurotransmitter binding to these receptors causes activation of adenylyl cyclase resulting in increased concentrations of cAMP and modulation of calcium ion channels within the cell. They are further classified into β1, β2, and β3 subtypes. β1-adrenoceptors: β1-adrenoceptors have equal affinities for... https://www.jove.com/v/14467 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14986.jpg Anatomy of the Adrenal Glands The adrenal or supra-renal glands, situated above the kidneys and aligned with the twelfth rib, are paired pyramid-shaped structures crucial for the body's stress response. During stress, these glands secrete hormones vital for adaptive physiological reactions. These glands possess a distinctive yellow tinge due to the stored cholesterol and fatty acids required for hormone synthesis. They are encased in a fibrous capsule and cushioned by fat. The adrenal gland comprises two distinct regions... https://www.jove.com/v/14986 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14987.jpg Hormones of the Adrenal Glands Adrenal hormones play a pivotal role in maintaining the body's electrolyte balance and orchestrating responses to stress, showcasing the intricate functions of the adrenal cortex and medulla. The adrenal cortex, a powerhouse of hormone synthesis, generates over two dozen corticosteroid hormones. The zona glomerulosa produces mineralocorticoids, exemplified by aldosterone, influencing the electrolyte composition of body fluids. The synthesis of glucocorticoids such as cortisol and corticosterone... https://www.jove.com/v/14987 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14991.jpg Cells and Secretions of the Pancreas The pancreas, a vital organ within the abdominal cavity, plays dual roles in the digestive and endocrine systems, collaborating with exocrine and endocrine cells to maintain optimal digestion and blood sugar levels. Exocrine function is carried out by acinar cells, organized into clusters known as acini. These cells contribute to digestion by releasing substantial quantities of enzyme-rich, alkaline digestive juices. Concurrently, the dispersed clusters of endocrine cells throughout the... https://www.jove.com/v/14991 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14992.jpg Hormones Regulating Blood Glucose Insulin is released by beta cells of the pancreas when blood glucose levels are high. It facilitates glucose absorption and utilization in insulin-dependent cells with insulin receptors on their plasma membranes. Insulin promotes glucose uptake by increasing the number of glucose transport proteins in the cell membrane, allowing glucose to enter the cell. As a result, glucose utilization and ATP production are enhanced. In addition to accelerating glucose uptake and utilization, insulin has... https://www.jove.com/v/14992 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17292.jpg Glucose Homeostasis: Pancreatic Islets and Insulin Secretion The pancreatic islets comprising only 1%-2% of the volume are highly vascularized and innervated mini-organs. They contain five endocrine cell types, including β cells that secrete insulin, which is synthesized as a single polypeptide chain, preproinsulin, processed to proinsulin, and finally to insulin and C-peptide. This process is complex and regulated, involving the Golgi complex, the endoplasmic reticulum, and the secretory granules of the β cell. Insulin and C-peptide are co-secreted in... https://www.jove.com/v/17292 87 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55687.jpg Mixed Primary Cultures of Murine Small Intestine Intended for the Study of Gut Hormone Secretion and Live Cell Imaging of Enteroendocrine Cells This protocol describes the isolation and culture of mixed murine small intestinal cells. These primary intestinal cultures enable the investigation of signaling pathways underlying gut peptide secretion using a number of techniques. https://www.jove.com/v/55687 556 2017-04-20T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58530.jpg Isolation, Fixation, and Immunofluorescence Imaging of Mouse Adrenal Glands Here we present a method to isolate adrenal glands from mice, fix the tissues, section them, and perform immunofluorescence staining. https://www.jove.com/v/58530 517 2018-10-02T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59016.jpg Primary Culture of Rat Adrenocortical Cells and Assays of Steroidogenic Functions The hormone secreted by the adrenal cortex is vital for animals against stress and diseases. Here, we present a protocol to culture the primary rat adrenal cells. It could be a good in vitro platform for investigating the mechanisms of the reagent of interest in adrenal steroidogenesis and lipid biosynthesis. https://www.jove.com/v/59016 273 2019-03-12T19:30:00+00:00 JoVE no https://visualize.jove.com/9716259-suppressive-effects-of-4-acetylaminophenylacetic-acid-actarit-on-experimental-autoimmune-encephalomyelitis-in-rats monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/224.jpg Induction and Clinical Scoring of Chronic-Relapsing Experimental Autoimmune Encephalomyelitis This video demonstrates the induction and clinical scoring of an animal model of multiple sclerosis: chronic-relapsing experimental autoimmune encephalomyelitis in DA rats. The disease, induced by immunizing rats with an emulsion containing whole rat spinal cord and complete Freund's adjuvant, presents clinical signs resembling the human disease. https://www.jove.com/v/224 2007-07-04T07:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54348.jpg Determining Immune System Suppression versus CNS Protection for Pharmacological Interventions in Autoimmune Demyelination This protocol describes how to determine whether pharmacological treatments for experimental autoimmune encephalomyelitis show CNS protection as a consequence of suppressing immune cell infiltration or are neuroprotective during the onslaught of immune cell infiltration. https://www.jove.com/v/54348 578 2016-09-12T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59249.jpg Visualizing Impairment of the Endothelial and Glial Barriers of the Neurovascular Unit during Experimental Autoimmune Encephalomyelitis In Vivo Here, we present protocols to investigate impairment of the neurovascular unit during experimental autoimmune encephalomyelitis in vivo. We specifically address how to determine blood-brain barrier permeability and gelatinase activity involved in leukocyte migration across the glia... https://www.jove.com/v/59249 650 2019-03-26T20:00:00+00:00 JoVE no https://visualize.jove.com/9731390-application-of-artificial-neural-network-for-micro-crack-and-damage-evaluation-of-bone monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14018.jpg Fractures: Bone Repair Treatment for a fracture is based on the type of break, the bone affected, and the patient's age. Minor fractures with no bone displacement are treated by immobilizing the fractured bone using a cast or splint. However, in the case of fractures with displaced bones, the broken bones are repositioned before immobilization to ensure successful healing without deformation and loss of function. The realignment of fractured bone ends is performed through a process called reduction. If the procedure... https://www.jove.com/v/14018 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16893.jpg Microcracking in Concrete Microcracking in concrete refers to the tiny cracks that can form within the material even before any external load is applied. These microcracks typically occur at the interface between the coarse aggregate and the hydrated cement paste, often as a result of differential volume changes prompted by variations in stress-strain behavior, as well as thermal and moisture movement. Initially, these microcracks remain stable and do not grow substantially until the concrete is stressed to about 30... https://www.jove.com/v/16893 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64262.jpg Assessment of Bone Fracture Healing Using Micro-Computed Tomography Micro-computed tomography (µCT) is a non-destructive imaging tool that is instrumental in assessing bone structure in preclinical studies, however there is a lack of consensus on µCT procedures for analyzing the bone healing callus. This study provides a step-by-step µCT protocol that allows the monitoring of fracture healing. https://www.jove.com/v/64262 724 2022-12-09T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67904.jpg Longitudinal Micro-Computed Tomography Image Analysis for User-Defined Region of Interest in Critical-Sized Bone Defects We present a method for analyzing a user-defined region of interest (ROI) in a longitudinal in vivo rat radial defect model. This method enables comparative analysis between different scaffolds previously limited by variations in microcomputed tomography (µCT) scan field of view, specimen orientation, and baseline presence of scaffold. https://www.jove.com/v/67904 519 2025-06-24T20:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/69252.jpg Automated Joint Space Detection Improves Bone Segmentation Accuracy The development of an automated joint space detection workflow enabled high-throughput segmentation of distinct murine hindpaw bones with >98% accuracy in wild-type animals. Flexible application to forepaws and paws with inflammatory-erosive arthritis was achieved, but with deprecated performance that warrants further optimization in future studies using publicly available data. https://www.jove.com/v/69252 405 2025-11-28T20:50:00+00:00 JoVE no https://visualize.jove.com/9735569-stochastic-complexity-measures-for-physiological-signal-analysis monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16029.jpg Signal and System A signal x(t) is a set of data or a time function representing a variable of interest. Signals typically convey information about a phenomenon, such as atmospheric temperature, humidity, human voice, television images, a dog's bark, or birdsongs. More generally, a signal can be a function of more than one independent variable. For instance, images depend on horizontal and vertical positions and can be regarded as two-dimensional signals. However, this text will focus on one-dimensional signals... https://www.jove.com/v/16029 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16030.jpg Classification of Signals In signal processing, signals are classified based on various characteristics: continuous-time versus discrete-time, periodic versus aperiodic, analog versus digital, and causal versus noncausal. Each category highlights distinct properties crucial for understanding and manipulating signals. A continuous-time signal holds a value at every instant in time, representing information seamlessly. In contrast, a discrete-time signal holds values only at specific moments, often denoted as x(n), where... https://www.jove.com/v/16030 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16040.jpg Basic Continuous Time Signals Basic continuous-time signals include the unit step function, unit impulse function, and unit ramp function, collectively referred to as singularity functions. Singularity functions are characterized by discontinuities or discontinuous derivatives. The unit step function, denoted u(t), is zero for negative time values and one for positive time values, exhibiting a discontinuity at t=0. This function often represents abrupt changes, such as the step voltage introduced when turning a car's... https://www.jove.com/v/16040 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16478.jpg Variability: Analysis Measures of variability are statistical metrics that reveal the dispersion pattern within a dataset. They are pivotal in biostatistics, providing insights into the heterogeneity within health and biological data. Variability signifies the degree to which data points diverge from one another, helping researchers understand the potential range of values and associated uncertainty within the data. The range is a simple measure of variability, indicating the difference between the highest and... https://www.jove.com/v/16478 71 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50131.jpg Applications of EEG Neuroimaging Data: Event-related Potentials, Spectral Power, and Multiscale Entropy Neuroimaging researchers typically consider the brain's response as the mean activity across repeated experimental trials and disregard signal variability over time as "noise". However, it is becoming clear that there is signal in that noise. This article describes the novel method of multiscale entropy for quantifying brain signal variability in the time domain. https://www.jove.com/v/50131 675 2013-06-27T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56452.jpg Microstate and Omega Complexity Analyses of the Resting-state Electroencephalography This article describes the protocol underlying electroencephalography (EEG) microstate analysis and omega complexity analysis, which are two reference-free EEG measures and highly valuable to explore the neural mechanisms of brain disorders. https://www.jove.com/v/56452 400 2018-06-15T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59827.jpg Dynamic Digital Biomarkers of Motor and Cognitive Function in Parkinson's Disease This protocol offers a digitization of portions of traditional clinical tasks commonly used to measure cognition and motor control in Parkinson’s disease. Clinical tasks are digitized while biophysical rhythms are co-registered from different functional levels of the nervous systems, ranging from voluntary, spontaneous, automatic to autonomic. https://www.jove.com/v/59827 628 2019-07-24T22:00:00+00:00 JoVE no https://visualize.jove.com/9755512-an-architecture-for-distributed-visual-memory monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2108.jpg Eye Movement Monitoring of Memory Eye movement monitoring (or eye tracking) reveals where in space the eyes linger, when and for how long. Here, we demonstrate how eye tracking can be used to investigate the integrity of memory in multiple participant populations, without requiring verbal, or otherwise explicit, reports. https://www.jove.com/v/2108 486 2010-08-16T00:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/3307.jpg Cross-Modal Multivariate Pattern Analysis Classical multivariate pattern analysis predicts sensory stimuli a subject perceives from neural activity in the corresponding cortices (e.g. visual stimuli from activity in visual cortex). Here, we apply pattern analysis cross-modally and show that sound- and touch-implying visual stimuli can be predicted from activity in auditory and somatosensory cortices, respectively. https://www.jove.com/v/3307 831 2011-11-09T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17769.jpg Visual System Light enters the eye through the cornea, a transparent, dome-shaped surface covering the surface of the eyeball that helps to direct and focus incoming light. This light is then channeled toward the pupil, an adjustable opening whose size is controlled by the iris. The iris, a pigmented muscle, regulates the amount of light entering the eye by contracting or dilating the pupil, thereby ensuring optimal light levels for clear vision. Once through the pupil, the light passes through the lens, a... https://www.jove.com/v/17769 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17779.jpg Parallel Processing The brain processes sensory information rapidly due to parallel processing, which involves sending data across multiple neural pathways at the same time. This method allows the brain to manage various sensory qualities, such as shapes, colors, movements, and locations, all concurrently. For instance, when observing a forest landscape, the brain simultaneously processes the movement of leaves, the shapes of trees, the depth between them, and the various shades of green. This enables a quick and... https://www.jove.com/v/17779 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18168.jpg Understanding Memory Memory is the retention of information or experiences over time, facilitated through three main processes: encoding, storage, and retrieval. Encoding is the process of inputting information into the memory system. For instance, when listening to a lecture, watching a play, reading a book, or having a conversation, the brain is actively encoding information. This initial stage involves transforming sensory input into a form that can be processed and stored by the brain. Various factors, such as... https://www.jove.com/v/18168 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18169.jpg System of Memory Memory is categorized into three major systems: sensory memory, short-term memory (STM), and long-term memory (LTM). These systems differ in their capacity and the duration for which they can hold information. Sensory memory captures raw sensory input from the environment, holding it for just a few seconds or less. For example, on hearing a brief, loud sound, like a car horn honking, the sound seems to linger in the mind for a moment even after it stops. This is an instance of sensory memory... https://www.jove.com/v/18169 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18174.jpg Storage A schema is a mental framework that helps individuals organize and interpret information. Schemata, formed from previous experiences, influence how we process new information: how we encode it, the inferences we make, and how we retrieve it. For instance, a schema for what a typical classroom looks like might include desks, a teacher's desk, a whiteboard, and students in such an environment. This expectation helps us quickly understand and navigate new classrooms without needing to analyze each... https://www.jove.com/v/18174 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18194.jpg Mnemonic Devices Mnemonic devices are cognitive tools that facilitate memory retention by linking new information to familiar patterns or organizational strategies. These techniques are beneficial for remembering complex or lengthy sets of information by simplifying and structuring them in easily retrievable ways. Acronyms Acronyms are created by using the initial letters of a series of words to form a new word or phrase. This approach condenses complex information into a single, memorable entity. For example,... https://www.jove.com/v/18194 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56992.jpg Visualization of Cortical Modules in Flattened Mammalian Cortices This article describes a detailed methodology to obtain flattened tangential sections from mammalian cortices and visualize cortical modules using histochemical and immunohistochemical methods. https://www.jove.com/v/56992 529 2018-01-22T23:00:00+00:00 JoVE no https://visualize.jove.com/9784226-discrete-conventional-signalling-of-a-continuous-variable monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16029.jpg Signal and System A signal x(t) is a set of data or a time function representing a variable of interest. Signals typically convey information about a phenomenon, such as atmospheric temperature, humidity, human voice, television images, a dog's bark, or birdsongs. More generally, a signal can be a function of more than one independent variable. For instance, images depend on horizontal and vertical positions and can be regarded as two-dimensional signals. However, this text will focus on one-dimensional signals... https://www.jove.com/v/16029 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16030.jpg Classification of Signals In signal processing, signals are classified based on various characteristics: continuous-time versus discrete-time, periodic versus aperiodic, analog versus digital, and causal versus noncausal. Each category highlights distinct properties crucial for understanding and manipulating signals. A continuous-time signal holds a value at every instant in time, representing information seamlessly. In contrast, a discrete-time signal holds values only at specific moments, often denoted as x(n), where... https://www.jove.com/v/16030 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16039.jpg Even and Odd Signals An even signal, whether in continuous-time or discrete-time, is defined by its symmetry with its time-reversed version. Mathematically, this is represented as for continuous-time signals and for discrete-time signals. Even signals exhibit symmetry around the vertical axis, meaning the signal for negative time values mirrors that for positive time values. In contrast, a signal is termed odd if it does not match its time-reversed counterpart, represented by for continuous-time signals and for... https://www.jove.com/v/16039 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16040.jpg Basic Continuous Time Signals Basic continuous-time signals include the unit step function, unit impulse function, and unit ramp function, collectively referred to as singularity functions. Singularity functions are characterized by discontinuities or discontinuous derivatives. The unit step function, denoted u(t), is zero for negative time values and one for positive time values, exhibiting a discontinuity at t=0. This function often represents abrupt changes, such as the step voltage introduced when turning a car's... https://www.jove.com/v/16040 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16043.jpg Basic Discrete Time Signals The unit step sequence is defined as 1 for zero and positive values of the integer n. This sequence can be graphically displayed using a set of eight sample points, showing a step function starting from n=0 and remaining constant thereafter. The unit impulse or sample sequence is mathematically expressed as zero for all n values except at n=0, where it is one. The unit impulse sequence, denoted by δ(n), is the first difference of the unit step sequence, while the unit step sequence u(n) is the... https://www.jove.com/v/16043 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16077.jpg Sampling Continuous Time Signal In signal processing, a continuous-time signal can be sampled using an impulse-train sampling technique, followed by the zero-order hold method. Impulse-train sampling involves the use of a periodic impulse train, which consists of a series of delta functions spaced at regular intervals determined by the sampling period. When a continuous-time signal is multiplied by this impulse train, it generates impulses with amplitudes corresponding to the signal's values at the sampling points. In the... https://www.jove.com/v/16077 71 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52287.jpg Signal Attenuation as a Rat Model of Obsessive Compulsive Disorder The goal of the protocol described in this paper is to induce compulsive-like behavior in rats for the study of obsessive-compulsive disorder (OCD). This behavior is precipitated by attenuating a signal indicating that a lever-press response was effective in producing food. https://www.jove.com/v/52287 569 2015-01-09T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61943.jpg Real-Time Proxy-Control of Re-Parameterized Peripheral Signals using a Close-Loop Interface We present protocols and methods of analyses to build co-adaptive interfaces that stream, parameterize, analyze, and modify human body and heart signals in close-loop. This setup interfaces signals derived from the peripheral and central nervous systems of the person with external sensory inputs to help track biophysical change. https://www.jove.com/v/61943 714 2021-05-08T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68390.jpg High-precision Electromagnetic Flowmeter with Empty Pipe Detection via Complex Programmable Logic Device-based Waveform Recognition This study improves electromagnetic flowmeter accuracy by optimizing excitation waveforms, applying multi-stage filtering, and using Complex Programmable Logic Device (CPLD)-based rectification. A novel waveform-based empty pipe detection method enhances reliability. Experiments show 0.1% accuracy within 0.1-15 m/s, validating industrial applicability. https://www.jove.com/v/68390 311 2025-06-27T20:05:00+00:00 JoVE no https://visualize.jove.com/9786944-determination-of-the-functional-domain-organization-of-the-importin-alpha-nuclear-import-factor monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2040.jpg Single-Molecule Imaging of Nuclear Transport Single molecule microscopy approch provided novel insights into nuclear transport. https://www.jove.com/v/2040 733 2010-06-10T00:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11935.jpg Nuclear Protein Sorting Nuclear protein sorting is the selective trafficking of histones, polymerases, gene regulatory proteins into the nucleus and exporting RNAs and ribosomes to the cytosol. It is a tightly controlled process that regulates gene expression within a cell. Proteins targeted to the nucleus carry nuclear localization signals or NLS recognized by import receptors in the cytosol. Similarly, proteins with nuclear export signals are recognized by export receptors. Import and export receptors are... https://www.jove.com/v/11935 94 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11936.jpg Nuclear Localization Signals and Import Proteins targeted to the nucleus carry short stretches of amino acid sequences called the nuclear localization signal or NLS. Classical nuclear localization signals are of two types: monopartite and bipartite NLS. Monopartite classical NLS (cNLS) consists of a single cluster of 4-8 amino acids. Bipartite cNLS consists of two clusters of 2-3 amino acids and a 9-12 residue long proline-rich linker bridging the two clusters. Signal clusters are rich in positively charged amino acids such as... https://www.jove.com/v/11936 106 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11937.jpg Nuclear Export The nucleus restricts several proteins within and allows others to pass. The restricted proteins possess a nuclear retention sequence or NRS, anchoring them to the nuclear lamins and preventing their transport to the cytosol. The non-restricted proteins, after their synthesis, are transported to their site of action, such as the cytosol or other organelles, with the help of nuclear export signals or NES. NES are of three types- the canonical 10-residue long leucine-rich signal and other... https://www.jove.com/v/11937 102 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11938.jpg Directionality of Nuclear Transport Ras-related nuclear protein or Ran is a small G protein that cycles between its GTP and GDP bound states. Ran specific regulators, a Ran GTPase Activating Protein or RanGAP present in the cytosol and a Ran guanine nucleotide exchange factor or RanGEF present inside the nucleus regulate GTP/GDP exchange. A high concentration of GTP inside the cells, in addition to this asymmetric distribution of Ran-specific regulators, leads to a higher RanGTP concentration inside the nucleus. This... https://www.jove.com/v/11938 102 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11939.jpg Regulation of Nuclear Protein Sorting Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the... https://www.jove.com/v/11939 105 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11941.jpg Mitochondrial Precursor Proteins Mitochondrial precursors are partially unfolded or loosely folded polypeptide chains. Newly synthesized precursors are inhibited from spontaneously folding into their native conformation by the cytosolic chaperones, heat shock proteins 70 (Hsp70), and mitochondrial import stimulation factors (MSFs). Precursors bound to MSFs are guided to the TOM70-TOM37 receptors, while precursors bound to Hsp70 chaperones are targetted to TOM20-TOM22 receptor complexes. Most of the mitochondrial precursors... https://www.jove.com/v/11941 99 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59329.jpg Identification of Nucleolar Factors During HIV-1 Replication Through Rev Immunoprecipitation and Mass Spectrometry Here we describe Rev immunoprecipitation in the presence of HIV-1 replication for mass spectrometry. The methods described can be used for the identification of nucleolar factors involved in the HIV-1 infectious cycle and are applicable to other disease models for the characterization of understudied pathways. https://www.jove.com/v/59329 578 2019-06-26T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63055.jpg Measurement of Protein Import Capacity of Skeletal Muscle Mitochondria Mitochondria are key metabolic organelles that exhibit a high level of phenotypic plasticity in skeletal muscle. The import of proteins from the cytosol is a critical pathway for organelle biogenesis, essential for the expansion of the reticulum and the maintenance of mitochondrial function. Therefore, protein import serves as a barometer of cellular health. https://www.jove.com/v/63055 541 2022-01-07T20:30:00+00:00 JoVE no https://visualize.jove.com/9811594-sensory-neuroscience-visualizing-the-auditory-cortex monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4262.jpg Mapping Cortical Dynamics Using Simultaneous MEG/EEG and Anatomically-constrained Minimum-norm Estimates: an Auditory Attention Example We use magneto- and electroencephalography (MEG/EEG), combined with anatomical information captured by magnetic resonance imaging (MRI), to map the dynamics of the cortical network associated with auditory attention. https://www.jove.com/v/4262 525 2012-10-24T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10853.jpg Hearing When we hear a sound, our nervous system is detecting sound waves—pressure waves of mechanical energy traveling through a medium. The frequency of the wave is perceived as pitch, while the amplitude is perceived as loudness. Sound waves are collected by the external ear and amplified as they travel through the ear canal. When sounds reach the junction between the outer and middle ear, they vibrate the tympanic membrane—the eardrum. The resulting mechanical energy causes the attached ossicles—a... https://www.jove.com/v/10853 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10858.jpg Vision Vision is the result of light being detected and transduced into neural signals by the retina of the eye. This information is then further analyzed and interpreted by the brain. First, light enters the front of the eye and is focused by the cornea and lens onto the retina—a thin sheet of neural tissue lining the back of the eye. Because of refraction through the convex lens of the eye, images are projected onto the retina upside-down and reversed. Light is absorbed by the rod and cone... https://www.jove.com/v/10858 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14907.jpg Motor and Sensory Areas of the Cortex The cerebral cortex, the brain's outermost layer, is pivotal in processing complex cognitive tasks, emotions, and various sensory inputs and executing voluntary motor activities. This intricate structure is divided into three primary functional areas: the motor areas, sensory areas, and association areas. Motor Areas The motor areas located in the frontal lobe are central to controlling voluntary movements. This region is further subdivided into the primary motor cortex and the premotor cortex. https://www.jove.com/v/14907 74 2025-06-13T16:10:51+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14908.jpg Association Areas of the Cortex Association areas are regions of the cerebral cortex that do not have a specific sensory or motor function. Instead, they integrate and interpret information from various sources to enable higher cognitive processes such as memory, learning, and decision-making. Some key association areas include the following: Prefrontal Association Area: This area is located in the frontal lobe and is involved in planning, decision-making, and moderating social behavior. It connects with primary motor areas,... https://www.jove.com/v/14908 81 2025-06-13T16:11:09+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14970.jpg Auditory Pathway Auditory pathways constitute the complex neural circuits responsible for transmitting and interpreting auditory information from the peripheral auditory system to the brain. Sound waves are initially captured by the outer ear, funneled through the ear canal, and reach the tympanic membrane (eardrum). These vibrations are transmitted via the middle ear's ossicles to the inner ear's cochlea. When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking the... https://www.jove.com/v/14970 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17749.jpg Somatosensory, Motor, and Association Cortex The somatosensory cortex in the parietal lobes is crucial for interpreting sensory data such as touch, temperature, and proprioception. The somatosensory cortex, situated in the parietal lobes, plays a vital role in interpreting sensory information like touch, temperature, and proprioception—awareness of body position. This specialized brain region features an organized structure wherein neurons at the top primarily process sensations originating from the lower body. In contrast, those at the... https://www.jove.com/v/17749 83 2026-03-20T20:23:54+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52642.jpg A Large Lateral Craniotomy Procedure for Mesoscale Wide-field Optical Imaging of Brain Activity This protocol presents a method for creating a large unilateral craniotomy over the temporal and parietal regions of the mouse cerebral cortex. This is especially useful for real time imaging over an expansive area of a cortical hemisphere. https://www.jove.com/v/52642 605 2017-05-07T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67983.jpg Multiscale Investigations of Cortical Processing by Integrating Laminar Polytrodes and Optogenetics with Micro Electrocorticography in Rodents Here, we present two protocols for high-density micro-electrocorticography (µEcoG) recording in rats and mice, including surgical, implantation, and recording methods. µECoG recordings are performed in combination with either laminar polytrode recording in the rat auditory cortex or with optogenetic manipulation of neural activity in the mouse somatosensory cortex. https://www.jove.com/v/67983 472 2025-05-23T20:30:00+00:00 JoVE no https://visualize.jove.com/9921610-ordinal-invariant-measures-for-individual-and-group-changes-in-ordered-categorical-data monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12574.jpg Ordinal Level of Measurement The way a set of data is measured is called its level of measurement. Correct statistical procedures depend on a researcher being familiar with levels of measurement. For analysis, data are classified into four levels of measurement—nominal, ordinal, interval, and ratio. Data measured using an ordinal scale are similar to nominal scale data, but there is one major difference. The ordinal scale data can be ordered. An example of ordinal scale data is a list of the top five national parks in the... https://www.jove.com/v/12574 55 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12797.jpg How Data are Classified: Categorical Data A variable, usually notated by capital letters such as X and Y, is a characteristic or measurement that can be determined for each member of a population. Data are the actual values of variables. They may be numbers, or they may be words. Datum is a single value. Data are classified based on whether they are measurable or not. Categorical data cannot be measured; instead, it can be divided into categories. For example, if Y denotes a person's party affiliation, some examples of Y include... https://www.jove.com/v/12797 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12798.jpg Nominal Level of Measurement The way a set of data is measured is called its level of measurement. Correct statistical procedures depend on a researcher being familiar with levels of measurement. Not every statistical operation can be used with every set of data. For analysis, data are classified into four levels of measurement—nominal, ordinal, interval, and ratio. The data that cannot be measured but can be grouped into categories fall under the nominal level of measurement. Data that is measured using a nominal scale is... https://www.jove.com/v/12798 56 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13621.jpg One-Way ANOVA: Equal Sample Sizes One-Way ANOVA can be performed on three or more samples with equal or unequal sample sizes. When one-way ANOVA is performed on two datasets with samples of equal sizes, it can be easily observed that the computed F statistic is highly sensitive to the sample mean. Different sample means can result in different values for the variance estimate: variance between samples. This is because the variance between samples is calculated as the product of the sample size and the variance between the... https://www.jove.com/v/13621 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14156.jpg Ranks Unlike parametric methods, nonparametric statistics are ideal for nominal and ordinal data, requiring fewer assumptions about the population's nature or distribution. This makes nonparametric methods easier to apply and interpret, as they do not depend on parameters like mean or standard deviation. One common approach in nonparametric analysis is to sort data according to a specific criterion. For instance, we might arrange weather data from hottest to coldest days in a month or rank cities... https://www.jove.com/v/14156 62 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17594.jpg Friedman Two-way Analysis of Variance by Ranks Friedman's Two-Way Analysis of Variance by Ranks is a nonparametric test designed to identify differences across multiple test attempts when traditional assumptions of normality and equal variances do not apply. Unlike conventional ANOVA, which requires normally distributed data with equal variances, Friedman's test is ideal for ordinal or non-normally distributed data, making it particularly useful for analyzing dependent samples, such as matched subjects over time or repeated measures from... https://www.jove.com/v/17594 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59575.jpg Using the Race Model Inequality to Quantify Behavioral Multisensory Integration Effects The current study aims to provide a step-by-step tutorial for calculating the magnitude of multisensory integration effects in an effort to facilitate the production of translational research studies across diverse clinical populations. https://www.jove.com/v/59575 493 2019-05-10T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60035.jpg Applying an eMASS Customization Program as a Research Tool to Evaluate Consumer Benefits Presented here is a protocol to examine consumer responses toward mass customization in the context of online retailing. The protocol details the online survey procedure and how to analyze data using structural equation modeling and group differences using latent mean analyses. https://www.jove.com/v/60035 507 2019-09-27T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67031.jpg Advancing Dyslexia Assessment in Children Through Computerized Testing The Multimedia Battery for Assessment of General-Domain and Specific-Domain Skills in Reading is a reliable and valid multimedia battery designed to assess cognitive and basic reading skills. It enables the generation of a comprehensive cognitive and reading performance profile, which is particularly beneficial for children with dyslexia. https://www.jove.com/v/67031 540 2024-08-16T21:00:00+00:00 JoVE no https://visualize.jove.com/9922242-coordinate-intracellular-expression-of-salmonella-genes-induced-during-infection monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12034.jpg Reporter Genes Reporter genes are a type of protein-coding gene that are often tagged to a gene of interest. Once inside a target cell, reporter genes usually produce visually identifiable characteristics like fluorescence and luminescence when expressed along with the gene of interest. Thus, reporter genes “report” the presence or absence of genes of interest in an organism, determine the gene expression pattern, or track the physical location of a DNA segment or protein in the cell. Commonly used reporter... https://www.jove.com/v/12034 131 JoVE no https://cloudfront.jove.com/files/ftp_upload/19541/19541_article_thumb_19541.jpg Stringent Response in E. coli Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs... https://www.jove.com/v/19541 83 2025-06-12T16:16:17+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60567.jpg NF-κB-dependent Luciferase Activation and Quantification of Gene Expression in Salmonella Infected Tissue Culture Cells Here, we present a protocol to quickly and easily measure nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation in cell lines expressing NF-κB::luciferase reporter constructs, via measurements of luminescence in the cell lysate. Additionally, gene expression is determined via RT-qPCR isolated from cells infected with Salmonella Typhimurium. https://www.jove.com/v/60567 657 2020-01-12T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64263.jpg Automated Analysis of Intracellular Phenotypes of Salmonella Using ImageJ Salmonella invades and replicates inside intestinal epithelial cells both in Salmonella-specific vacuoles and free in the cytosol (hyper-replication). A high-throughput fluorescence microscopy-based protocol is described here to quantify the intracellular phenotypes of Salmonella by two complementary image analyses through ImageJ, reaching single-cell resolution and scoring. https://www.jove.com/v/64263 639 2022-08-09T21:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64382.jpg Super-Resolution Imaging of Bacterial Secreted Proteins Using Genetic Code Expansion This article provides a straightforward and clear protocol to label Salmonella secreted effectors using genetic code expansion (GCE) site-specifically and image the subcellular localization of secreted proteins in HeLa cells using direct stochastic optical reconstruction microscopy (dSTORM)... https://www.jove.com/v/64382 791 2023-02-10T21:23:00+00:00 JoVE no https://visualize.jove.com/9929308-design-of-a-modular-extensible-decision-support-system-for-arrhythmia-therapy monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3750.jpg A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation Dual-chamber implantable cardioverter-defibrillators (ICDs) may improve detection of atrial fibrillation as well as differentiation of tachycardias. However, this advantage is undermined by complications associated with the second electrode, which is required in conventional dual chamber devices. Therefore, BIOTRONIK has developed a new electrode called the LinoxSMART S DX that, when used in conjunction with the Lumax DX ICD, offers dual-chamber detection without the risks associated with the... https://www.jove.com/v/3750 1000 2012-02-28T22:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15276.jpg Disturbances in Heart Rhythm Arrhythmia or dysrhythmia refers to an abnormal heart rhythm caused by a defect in the heart's conduction system. It can cause the heart to beat irregularly, too quickly, or too slowly, leading to symptoms like chest pain, shortness of breath, and fainting. Factors such as stress, caffeine, alcohol, nicotine, cocaine, certain drugs, congenital defects, diseases, and electrolyte abnormalities can trigger arrhythmias. Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart... https://www.jove.com/v/15276 89 2025-07-29T16:29:05+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17938/17938_article_thumb_17938.jpg Dysrhythmias I: Introduction Dysrhythmias refers to abnormalities in the heart's rhythm. They result from disruptions in the heart's electrical conduction system, which includes the sinoatrial(SA)node, atrioventricular(AV) node, the bundle of His, bundle branches, and Purkinje fibers.Definition and PathophysiologyDysrhythmias result from disorders of impulse formation, impulse conduction, or both. The heart contains specialized cells in the sinoatrial node, atrioventricular node, and the bundle of His and Purkinje fibers... https://www.jove.com/v/17938 75 2025-06-19T16:35:29+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17939/17939_article_thumb_17939.jpg Dysrhythmias II: Classification of Tachyarrhythmias Tachyarrhythmias are a type of dysrhythmia where the heart rate exceeds 100 beats per minute. Here are some common types of tachyarrhythmias:Sinus TachycardiaSinus tachycardia originates from increased impulses from the sinus node, leading to an elevated heart rate. It is often triggered by stress, fever, or exercise.Patients may experience palpitations, a sensation of a racing heart, dizziness, and chest discomfort.Causes and Risk Factors: Common causes include physical exertion, emotional... https://www.jove.com/v/17939 88 2025-06-19T16:35:48+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17942/17942_article_thumb_17942.jpg Dysrhythmias V: Evaluating Dysrhythmias Dysrhythmias, also known as arrhythmias, are disturbances in the heart's rhythm that range from benign to life-threatening. A thorough evaluation is crucial for appropriate management and involves a comprehensive medical history, physical examination, and various diagnostic tests.Medical HistorySymptoms: Collect detailed information on palpitations, dizziness, syncope, chest pain, and fatigue. Note their onset, frequency, and triggers.Previous Cardiac Issues: Document any history of heart... https://www.jove.com/v/17942 90 2025-06-19T16:36:46+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17943/17943_article_thumb_17943.jpg Dysrhythmias VI: Management of Dysrhythmias Dysrhythmia management involves a multifaceted approach, incorporating pharmacological treatments, medical procedures, surgical interventions, lifestyle modifications, and patient education.Pharmacological ManagementAntiarrhythmic Drugs:Class I (Sodium Channel Blockers): This class includes quinidine and procainamide, which reduce the speed of impulse conduction in the heart, stabilize the cardiac membrane, and control arrhythmias. Quinidine and procainamide are Class IA agents that prolong the... https://www.jove.com/v/17943 85 2025-06-19T16:37:04+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17944/17944_article_thumb_17944.jpg Dysrhythmias VII: Nursing Management of Dysrhythmias Nursing management of dysrhythmias involves the following:AssessmentSubjective Assessment:The initial step involves gathering patient-reported symptoms such as dizziness, palpitations, and chest discomfort. It is crucial to collect a detailed history, including previous heart conditions, current medication use, and lifestyle factors like caffeine and alcohol consumption.Objective Assessment:This involves observing clinical signs such as jugular venous distention, cool and pale skin, and... https://www.jove.com/v/17944 85 2025-06-19T16:37:24+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58132.jpg Hydra, a Computer-Based Platform for Aiding Clinicians in Cardiovascular Analysis and Diagnosis This article presents a protocol based on Hydra — a web-based system for clinical decision support that integrates a full and detailed set of functionalities and services required by physicians for complete cardiovascular analysis, risk assessment, early diagnosis, treatment, and monitoring over time. https://www.jove.com/v/58132 471 2018-09-26T20:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62386.jpg Analyzing Long-Term Electrocardiography Recordings to Detect Arrhythmias in Mice Here we present a step-by-step protocol for a semiautomated approach to analyze murine long-term electrocardiography (ECG) data for basic ECG parameters and common arrhythmias. Data are obtained by implantable telemetry transmitters in living and awake mice and analyzed using Ponemah and its analysis modules. https://www.jove.com/v/62386 367 2021-05-23T20:00:00+00:00 JoVE no https://visualize.jove.com/9989018-the-cognitive-determinants-of-performance-on-the-austin-maze monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3443.jpg Using MazeSuite and Functional Near Infrared Spectroscopy to Study Learning in Spatial Navigation MazeSuite is a complete toolset to prepare, present and analyze navigational and spatial experiments. Functional near-infrared spectroscopy (fNIR) is an optical brain imaging technique that enables noninvasive and portable monitoring of cerebral blood oxygenation changes. This paper summarizes collective use of MazeSuite and fNIR within a cognitive processing learning paradigm. https://www.jove.com/v/3443 1212 2011-10-08T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17822.jpg Cognitive Learning Cognitive learning is based on purposive behavior, incidental learning, and insight learning. E. C. Tolman's theory of purposive behavior emphasizes that much behavior is goal-directed. He argued that to understand behavior, we must look at the entire sequence of actions leading to a goal. For instance, high school students study hard, not just due to past reinforcement but also to achieve the goal of getting into a good college. Tolman introduced the idea that behavior is influenced by... https://www.jove.com/v/17822 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51194.jpg Barnes Maze Testing Strategies with Small and Large Rodent Models The dry-land Barnes maze is widely used to measure spatial navigation ability in response to mildly aversive stimuli. Over consecutive days, performance (e.g. latency to locate escape cage) of control subjects improves, indicative of normal learning and memory. Differences between rats and mice necessitate apparatus and methodology changes that are detailed here. https://www.jove.com/v/51194 779 2014-02-27T06:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52667.jpg The Double-H Maze: A Robust Behavioral Test for Learning and Memory in Rodents The goal of this protocol is to investigate spatial cognition in rodents. The double-H water maze is a novel test, which is particularly useful to elucidate the different components of learning, consolidation and memory, as well as the interplay of memory systems. https://www.jove.com/v/52667 541 2015-07-08T20:00:00+00:00 JoVE no https://visualize.jove.com/10023499-on-the-meaning-and-measurement-of-affective-instability-clues-from-chaos-theory monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11067.jpg Theory of Romantic Attachment in Adulthood Attachment is a long-standing connection or bond with others. While Attachment Theory was conceived in developmental psychology to describe infant-caregiver bonding, it's been extended into adulthood to include romantic relationships. The Basis of Attachment Theory in Development Building on the work of Harlow and others, John Bowlby developed the concept of attachment theory. He defined attachment as the affectional bond or tie that an infant forms with the mother (Bowlby, 1969). An infant... https://www.jove.com/v/11067 214 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18215.jpg Cognitive Theories: Schachter-Singer Theory of Emotion Stanley Schachter and Jerome Singer proposed the two-factor theory of emotion, which emphasizes the interplay between physiological arousal and cognitive labeling in forming emotional experiences. This theory suggests that emotions are not simply a result of physiological responses but rather a combination of these responses and the individual's cognitive interpretation of them. Physiological Arousal and Cognitive Labeling According to this theory, when an individual experiences physiological... https://www.jove.com/v/18215 80 JoVE no https://cloudfront.jove.com/files/ftp_upload/19901/19901_article_thumb_19901.jpg Self-Discrepancy and Its Effects Self-discrepancy theory explains how people compare their actual self to their ideal and ought selves and how mismatches between these self-guides can lead to emotional distress. Developed by E. Tory Higgins, the theory distinguishes among three components of self-concept: the actual self, the ideal self, and the ought self. These refer respectively to how individuals perceive themselves, how they aspire to be, and how they believe they are obligated to be. Emotional well-being, self-esteem,... https://www.jove.com/v/19901 89 2025-09-18T17:24:09+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19924/19924_article_thumb_19924.jpg The Influence of Affect on Cognition Positive affect significantly influences cognitive processes, including evaluation, memory, creativity, and social judgments. Compared to negative affect, positive emotional states promote more favorable interpretations of stimuli, cognitive flexibility, and heuristic processing. These effects highlight emotions' powerful role in shaping how individuals perceive, remember, and interact with the world.Influence on Evaluation and AttributionWhen individuals experience positive affect, they are... https://www.jove.com/v/19924 89 2025-09-18T17:24:14+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19925/19925_article_thumb_19925.jpg The Influence of Cognition on Affect Cognition plays a pivotal role in shaping emotional experiences, as demonstrated by Schachter and Singer’s two-factor theory of emotion. According to this model, emotion arises from a combination of physiological arousal and cognitive interpretation. The body’s physiological response to stimuli is ambiguous and only gains emotional significance through cognitive labeling. For instance, an increased heart rate and adrenaline surge while standing near an attractive person may be interpreted as... https://www.jove.com/v/19925 89 2025-09-18T17:24:13+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19968/19968_article_thumb_19968.jpg Hazan and Shaver's Attachment Styles Attachment theory, developed initially to explain infant–caregiver bonds, has been extended to illuminate patterns of intimacy in adult romantic relationships. Psychologists Cindy Hazan and Phillip Shaver proposed that the attachment styles observed in infancy form a framework for how individuals approach emotional closeness and conflict in adulthood. These attachment styles—secure, avoidant, and anxious—are linked to enduring patterns of behavior and emotional regulation in adult relationships. https://www.jove.com/v/19968 88 2025-09-18T17:23:43+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51484.jpg Measurement of Fronto-limbic Activity Using an Emotional Oddball Task in Children with Familial High Risk for Schizophrenia This paper describes how to use the emotional oddball task and fMRI to measure brain activation in children and adolescents at familial high risk for schizophrenia (FHR). FMRI was used to measure differences in fronto-striato-limbic regions during an emotional oddball task. Children with FHR exhibited abnormal functional activation during adolescence. https://www.jove.com/v/51484 788 2015-12-02T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51905.jpg Using the Threat Probability Task to Assess Anxiety and Fear During Uncertain and Certain Threat Potentiation of the startle reflex is measured via electromyography of the orbicularis oculi muscle during low (uncertain) and high (certain) probability electric shock threat in the Threat Probability Task. This provides an objective measure of distinct negative emotional states (fear/anxiety) for research on psychopathology, substance use/abuse, and broad affective science. https://www.jove.com/v/51905 678 2014-09-12T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53155.jpg Experimental Research Examining How People Can Cope with Uncertainty Through Soft Haptic Sensations To date research has focused on cognitive strategies people adopt to cope with uncertainty. This research examines instead an experiential way of dealing with uncertainty and introduces a set of experimental methods showing how the experience of haptic softness can serve as a tool to deal with uncertainty. https://www.jove.com/v/53155 547 2015-09-16T22:00:00+00:00 JoVE no https://visualize.jove.com/10024069-anxiety-in-patients-with-an-automatic-implantable-cardioverter-defibrillator-what-differentiates-them-from-panic-patients monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3750.jpg A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation Dual-chamber implantable cardioverter-defibrillators (ICDs) may improve detection of atrial fibrillation as well as differentiation of tachycardias. However, this advantage is undermined by complications associated with the second electrode, which is required in conventional dual chamber devices. Therefore, BIOTRONIK has developed a new electrode called the LinoxSMART S DX that, when used in conjunction with the Lumax DX ICD, offers dual-chamber detection without the risks associated with the... https://www.jove.com/v/3750 1000 2012-02-28T22:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15276.jpg Disturbances in Heart Rhythm Arrhythmia or dysrhythmia refers to an abnormal heart rhythm caused by a defect in the heart's conduction system. It can cause the heart to beat irregularly, too quickly, or too slowly, leading to symptoms like chest pain, shortness of breath, and fainting. Factors such as stress, caffeine, alcohol, nicotine, cocaine, certain drugs, congenital defects, diseases, and electrolyte abnormalities can trigger arrhythmias. Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart... https://www.jove.com/v/15276 89 2025-07-29T16:29:05+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17941/17941_article_thumb_17941.jpg Dysrhythmias IV: Characteristics of Bradyarrhythmias Bradyarrhythmias are cardiac rhythm disorders characterized by a slower-than-normal heart rate, typically defined as fewer than 60 beats per minute. Some of which are discussed here:Sinus BradycardiaSinus bradycardia presents a heart rate lower than 60 beats per minute, with a regular rhythm originating from the SA node. The ECG typically shows normal P waves preceding each QRS complex, a normal PR interval (0.12 to 0.20 seconds), and a normal QRS duration (0.06 to 0.10 seconds).First-Degree AV... https://www.jove.com/v/17941 78 2025-06-19T16:36:24+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17943/17943_article_thumb_17943.jpg Dysrhythmias VI: Management of Dysrhythmias Dysrhythmia management involves a multifaceted approach, incorporating pharmacological treatments, medical procedures, surgical interventions, lifestyle modifications, and patient education.Pharmacological ManagementAntiarrhythmic Drugs:Class I (Sodium Channel Blockers): This class includes quinidine and procainamide, which reduce the speed of impulse conduction in the heart, stabilize the cardiac membrane, and control arrhythmias. Quinidine and procainamide are Class IA agents that prolong the... https://www.jove.com/v/17943 85 2025-06-19T16:37:04+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17948/17948_article_thumb_17948.jpg Cardiopulmonary Resuscitation III: AED Use Introduction to AEDAn Automated External Defibrillator (AED) is a portable medical device that analyzes the heart's rhythm and, if necessary, delivers an electrical shock to help the heart re-establish an effective rhythm during sudden cardiac arrest (SCA). SCA occurs when the heart suddenly and unexpectedly stops beating, leading to a loss of blood flow to the brain and other vital organs. In such emergencies, time is of the essence, and using an AED, combined with Cardiopulmonary... https://www.jove.com/v/17948 83 2025-06-19T16:38:36+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18437/18437_article_thumb_18437.jpg ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias Arrhythmia is a condition characterized by an irregular heart rhythm, with ECG changes that differ based on its origin and nature. The types of arrhythmias discussed below include atrial, junctional, and ventricular arrhythmias.Atrial ArrhythmiasPremature Atrial Complexes (PACs): PACs are early atrial beats caused by stress, caffeine, alcohol, electrolyte imbalances, hypoxia, hyperthyroidism, or certain medications (e.g., bronchodilators and decongestants). The ECG shows early P waves with an... https://www.jove.com/v/18437 85 2025-06-19T16:15:27+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18604.jpg Panic Disorder Panic disorder is an anxiety disorder characterized by recurrent and sudden minutes-long episodes of intense fear, known as panic attacks. These attacks may feel like heart attacks and often happen without warning or a specific cause. They can include symptoms such as rapid heart rate, shortness of breath, chest pain, trembling, sweating, dizziness, and a sense of helplessness. During a panic attack, individuals may feel as though they are experiencing a heart attack or are in a... https://www.jove.com/v/18604 87 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55727.jpg Reducing State Anxiety Using Working Memory Maintenance This protocol demonstrates how to measure anxiety-potentiated startle during the Sternberg Working Memory paradigm. https://www.jove.com/v/55727 497 2017-07-19T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60715.jpg Patient Directed Recording of a Bipolar Three-Lead Electrocardiogram using a Smartwatch with ECG Function We describe a protocol for the patient-directed registration of a three lead bipolar electrocardiogram by a smartwatch that functions identically to the Einthoven leads from standard electrocardiograms. This enables patients to record electrocardiograms on their own immediately after the onset of symptoms. https://www.jove.com/v/60715 303 2019-12-11T21:00:00+00:00 JoVE no https://visualize.jove.com/10071205-functional-analysis-of-multiple-aug-codons-in-the-transcripts-of-the-sta2-glucoamylase-gene-from-saccharomyces-cerevisiae monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11476.jpg From DNA to Protein The flow of genetic information in cells from DNA to mRNA to protein is described by the central dogma, which states that genes specify the sequence of mRNAs, which in turn specify the sequence of amino acids making up all proteins. The decoding of one molecule to another is performed by specific proteins and RNAs. Because the information stored in DNA is so central to cellular function, it makes intuitive sense that the cell would make mRNA copies of this information for protein synthesis... https://www.jove.com/v/11476 186 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11516.jpg Ligand Binding and Linkage Allosteric proteins have more than one ligand binding site; the binding of a ligand to any of these sites influences the binding of ligands to the other sites. When a protein is allosteric, its binding sites are called coupled or linked. In the case of enzymes, the site that binds to the substrate is known as the active site and the other site is known as the regulatory site. When a ligand binds to the regulatory site, this leads to conformational changes in the protein that can influence the... https://www.jove.com/v/11516 49 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11522.jpg Protein Complexes with Interchangeable Parts Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct. The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to... https://www.jove.com/v/11522 117 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11595.jpg tRNA Activation Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the... https://www.jove.com/v/11595 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11625.jpg Leaky Scanning During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R stands for... https://www.jove.com/v/11625 148 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12221.jpg Allosteric Proteins-ATCase Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor. Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,... https://www.jove.com/v/12221 79 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57982.jpg Saccharomyces cerevisiae Metabolic Labeling with 4-thiouracil and the Quantification of Newly Synthesized mRNA As a Proxy for RNA Polymerase II Activity The protocol described here is based on the genome-wide quantification of newly synthesized mRNA purified from yeast cells labeled with 4-thiouracil. This method allows to measure mRNA synthesis uncoupled from mRNA decay and, thus, provides an accurate measurement of RNA polymerase II transcription. https://www.jove.com/v/57982 561 2018-10-22T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63841.jpg An Integrated Approach for Microprotein Identification and Sequence Analysis The protocol described here provides detailed instructions on how to analyze genomic regions of interest for microprotein-coding potential using PhyloCSF on the user-friendly UCSC Genome Browser. Additionally, several tools and resources are recommended to further investigate sequence characteristics of identified microproteins to gain insight into their putative functions. https://www.jove.com/v/63841 577 2022-07-12T20:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/69945.jpg Comparative RNA Structure Analysis of Nascent and Mature Transcripts in Saccharomyces cerevisiae RNA secondary structure has primarily been observed in mature RNA with structure probing methods. Co-transcriptional Structure Tracking sequencing (CoSTseq) unifies nuclear run-on, which has been used to study Polymerase position on nascent RNA, with structure probing. CoSTseq thereby enables observation of RNA secondary structure in RNA under active transcription. https://www.jove.com/v/69945 552 2026-02-27T21:20:00+00:00 JoVE no https://visualize.jove.com/10086967-effect-of-right-atrial-isthmus-ablation-on-the-occurrence-of-atrial-fibrillation-observations-in-four-patient-groups-having-type-i-atrial-flutter-with-or-without-associated-atrial-fibrillation monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17865.jpg Cardiac Output I:Effect of Heart Rate on Cardiac Output Cardiac Output Cardiac output (CO) refers to the total amount of blood ejected by one of the ventricles in liters per minute (L/min). In a resting adult, CO ranges from 5 to 6 L/min, adjusting according to the body's metabolic requirements. Effect of Heart Rate on Cardiac Output Cardiac output adapts to metabolic demands during stress, physical activity, or illness. The autonomic nervous system regulates heart rate via the sinoatrial node. The parasympathetic nervous system decreases heart rate... https://www.jove.com/v/17865 79 JoVE no https://cloudfront.jove.com/files/ftp_upload/17899/17899_article_thumb_17899.jpg Mitral Stenosis I: Introduction Mitral Valve Stenosis (MVS) is a heart condition where the mitral valve narrows, impeding blood circulation from the left atrium to the left ventricle. The etiology and pathophysiology of this condition are multifaceted, leading to a cascade of cardiovascular complications.Causes of Mitral Valve StenosisRheumatic Heart Disease: It is the main cause of mitral valve stenosis, particularly in developing nations. This condition arises from rheumatic fever, an inflammatory illness resulting from... https://www.jove.com/v/17899 82 2025-06-19T09:18:36+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17941/17941_article_thumb_17941.jpg Dysrhythmias IV: Characteristics of Bradyarrhythmias Bradyarrhythmias are cardiac rhythm disorders characterized by a slower-than-normal heart rate, typically defined as fewer than 60 beats per minute. Some of which are discussed here:Sinus BradycardiaSinus bradycardia presents a heart rate lower than 60 beats per minute, with a regular rhythm originating from the SA node. The ECG typically shows normal P waves preceding each QRS complex, a normal PR interval (0.12 to 0.20 seconds), and a normal QRS duration (0.06 to 0.10 seconds).First-Degree AV... https://www.jove.com/v/17941 78 2025-06-19T09:36:24+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17951/17951_article_thumb_17951.jpg Heart Failure I: Introduction Heart failure refers to a clinical syndrome caused by structural or functional cardiac disorders that prevent the heart from pumping an adequate amount of blood to meet the body's metabolic needs. This condition often arises from myocardial infarction or ischemia, leading to decreased cardiac output, reduced tissue perfusion, impaired gas exchange, fluid volume imbalance, and decreased functional ability.Heart failure can result from disruptions in the mechanisms that regulate cardiac output... https://www.jove.com/v/17951 87 2025-06-19T09:39:44+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17954/17954_article_thumb_17954.jpg Heart Failure IV: Classification and Diagnostic Evaluation Heart failure can be classified in various ways, with the most common classifications based on physical activity limitations, disease progression, severity, and treatment strategies.The Functional Classification of Heart Failure divides patients into four categories based on physical activity limitation due to symptom burden.Class I: Patients in this class have cardiac disease but no physical activity limitations. Ordinary activities like walking, climbing stairs, or routine tasks do not cause... https://www.jove.com/v/17954 90 2025-06-19T09:40:42+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17960/17960_article_thumb_17960.jpg Cardiomyopathy III: Hypertrophic Cardiomyopathy Hypertrophic cardiomyopathy, or HCM, is an autosomal dominant genetic disorder characterized by asymmetric left ventricular hypertrophy without ventricular dilation. It is more common in men and is typically diagnosed in young, athletic adults.EtiologyHCM is primarily genetic and is caused by mutations in genes encoding sarcomeric proteins. Researchers have identified over 1400 mutations across at least 11 different genes. Among these, the most frequently occurring mutations are found in the... https://www.jove.com/v/17960 89 2025-08-11T10:09:32+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61779.jpg Organ Ischemia-Reperfusion Injury by Simulating Hemodynamic Changes in Rat Liver Transplant Model This paper provides a detailed description of how to build an animal model of the anhepatic phase (liver ischemia) in rats to facilitate basic research into ischemia-reperfusion injury after liver transplantation. https://www.jove.com/v/61779 607 2021-03-06T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62134.jpg Testing Acetylcholine Followed by Adenosine for Invasive Diagnosis of Coronary Vasomotor Disorders Coronary vasomotion disorders represent frequent functional causes of angina in patients with unobstructed coronaries. The underlying mechanism of angina (endotype) in these patients can be determined by a comprehensive invasive diagnostic procedure based on acetylcholine provocation testing followed by Doppler-derived assessment of the coronary flow reserve and microvascular resistance. https://www.jove.com/v/62134 358 2021-02-03T14:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63597.jpg Cox-Maze IV Procedure Concomitant with Valvular Surgery In Situs Inversus Dextrocardia: A Single-Center Experience in China We summarize the Cox-Maze IV procedure concomitant with valvular surgery performed in patients with situs inversus dextrocardia at this institution. https://www.jove.com/v/63597 522 2022-02-11T14:45:00+00:00 JoVE no https://visualize.jove.com/10095120-characterization-of-the-5-flanking-region-of-the-human-rna-specific-adenosine-deaminase-adar1-gene-and-identification-of-an-interferon-inducible-adar1-promoter monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10804.jpg RNA Interference RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated. This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used... https://www.jove.com/v/10804 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11611.jpg The Eukaryotic Promoter Region The eukaryotic promoter region is a segment of DNA located upstream of a gene. It contains an RNA polymerase binding site, a transcription start site, and several cis-regulatory sequences. The proximal promoter region is located in the vicinity of the gene and has cis-regulatory sequences and the core promoter. The core promoter is the binding site for RNA polymerase and is usually located between -35 and +35 nucleotides from the transcription start site. The distal promoter regions are... https://www.jove.com/v/11611 160 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11623.jpg RNA Editing RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or modification. The extent of RNA editing varies from a few hundred bases, in mitochondrial DNA of trypanosomes, to a just single base, in nuclear genes of mammals. Even a single base change in the pre-mRNA can convert a codon for one amino acid into the codon for another amino acid or a stop codon. This type of re-coding can significantly affect the... https://www.jove.com/v/11623 143 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11625.jpg Leaky Scanning During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R stands for... https://www.jove.com/v/11625 148 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10804.jpg RNA Interference RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated. This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used... https://www.jove.com/v/11627 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11611.jpg The Eukaryotic Promoter Region The eukaryotic promoter region is a segment of DNA located upstream of a gene. It contains an RNA polymerase binding site, a transcription start site, and several cis-regulatory sequences. The proximal promoter region is located in the vicinity of the gene and has cis-regulatory sequences and the core promoter. The core promoter is the binding site for RNA polymerase and is usually located between -35 and +35 nucleotides from the transcription start site. The distal promoter regions are... https://www.jove.com/v/13146 160 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59095.jpg Confocal Imaging of Double-Stranded RNA and Pattern Recognition Receptors in Negative-Sense RNA Virus Infection Double-stranded RNA produced during RNA virus replication can be recognized by pattern recognition receptors to induce an innate immune response. For negative-sense RNA viruses, the interaction between the low-level dsRNA and PRRs remains unclear. We have developed a confocal microscopy method to visualize arenavirus dsRNA and PRR in individual cells. https://www.jove.com/v/59095 404 2019-01-26T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63147.jpg CD Spectroscopy to Study DNA-Protein Interactions The interaction of an ATP-dependent chromatin remodeler with a DNA ligand is described using CD spectroscopy. The induced conformational changes on a gene promoter analyzed by the peaks generated can be used to understand the mechanism of transcriptional regulation. https://www.jove.com/v/63147 408 2022-02-10T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67216.jpg Determining the Serum Stability of Human Adenosine Deaminase 1 Enzyme In this article, we detail methods to characterize an enzyme's ability to retain function when incubated at 37 °C in human serum, a pharmacological property referred to as its serum stability. This ability may be a key factor in predicting an enzyme's pharmacokinetic profile and its suitability for therapeutic use. https://www.jove.com/v/67216 257 2024-09-27T21:25:00+00:00 JoVE no https://visualize.jove.com/10216175-multiple-single-units-and-population-responses-during-inhibitory-gating-of-hippocampal-auditory-response-in-freely-moving-rats monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/51706.jpg Whole-cell Patch-clamp Recordings from Morphologically- and Neurochemically-identified Hippocampal Interneurons Cortical networks are controlled by a small, but diverse set of inhibitory interneurons. Functional investigation of interneurons therefore requires targeted recording and rigorous identification. Described here is a combined approach involving whole-cell recordings from single or synaptically-coupled pairs of neurons with intracellular labeling, post-hoc morphological and immunocytochemical analysis. https://www.jove.com/v/51706 877 2014-09-30T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57714.jpg Recording Spatially Restricted Oscillations in the Hippocampus of Behaving Mice This protocol describes the recording of local field potentials with multi-shank linear silicon probes. Conversion of the signals using current source density analysis allows the reconstruction of local electrical activity in the mouse hippocampus. With this technique, spatially restricted brain oscillations can be studied in freely moving mice. https://www.jove.com/v/57714 430 2018-07-01T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57842.jpg Methods for the Discovery of Novel Compounds Modulating a Gamma-Aminobutyric Acid Receptor Type A Neurotransmission Here, we present protocols to discover compounds active at GABAA receptors, from the binding to the physiology and pharmacology. https://www.jove.com/v/57842 436 2018-08-16T20:00:00+00:00 JoVE no https://visualize.jove.com/10217143-humans-use-internal-models-to-estimate-gravity-and-linear-acceleration monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12657.jpg Second Law: Motion under Same Force Newton's laws can be applied to bodies at rest and bodies in motion. Newton's first law is applied to bodies in equilibrium, whereas the second law applies to accelerating bodies. To study accelerating bodies, first, the directions and magnitudes of acceleration and the applied forces are determined. Then, the free-body diagram is constructed, and Newton's second law is applied, considering the components of the forces in the x and y directions. Let's imagine a person is standing on a weighing... https://www.jove.com/v/12657 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12746.jpg Acceleration due to Gravity on Earth According to Newton's law of gravitation, the gravitational force on a body is proportional to its mass. According to Newton's second law of motion, the acceleration produced by an external force is inversely proportional to the force. Hence, the acceleration of an object under an external force of gravitation is independent of its mass. The acceleration of an object close to the Earth, because of the Earth's gravitational pull, is called the acceleration due to gravity. It is always directed... https://www.jove.com/v/12746 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12749.jpg Variation in Acceleration due to Gravity near the Earth's Surface An object's apparent weight is its weight measured by a spring balance at its location. It is different from its true weight, the force with which the Earth pulls it, because of the Earth's rotation. Mathematically, an object's apparent weight equals its true weight minus the centripetal force that keeps it in a circular motion along with the Earth's surface every 24 hours. The difference between the true and apparent weights is proportional to the square of the Earth's angular speed. Since the... https://www.jove.com/v/12749 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14271.jpg Internal Forces and Center of Gravity Internal forces and the center of gravity are fundamental concepts in mechanics, playing a crucial role in understanding the behavior and stability of structures and objects under various conditions. A comprehensive understanding of these principles is essential for engineers, architects, and designers to create safe and efficient systems. Internal forces are generated within a body due to the interaction between its particles. These forces can be categorized into tension, compression, and... https://www.jove.com/v/14271 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14720.jpg Measuring Acceleration Due to Gravity Consider a coffee mug hanging on a hook in a pantry. If the mug gets knocked, it oscillates back and forth like a pendulum until the oscillations die out. A simple pendulum can be described as a point mass and a string. Meanwhile, a physical pendulum is any object whose oscillations are similar to a simple pendulum, but cannot be modeled as a point mass on a string because its mass is distributed over a larger area. The behavior of a physical pendulum can be modeled using the principles of... https://www.jove.com/v/14720 72 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12646.jpg Acceleration due to Gravity on Earth Newton's second law is closely related to his first law of motion. It mathematically gives the cause-and-effect relationship between force and changes in motion. Newton's second law is quantitative and is used extensively to calculate what happens in situations involving a force. All external forces acting on a system add together to produce a net force Fnet. A larger net external force produces a larger acceleration. This acceleration is directly proportional to, and in the same direction as,... https://www.jove.com/v/15565 55 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50977.jpg Oscillation and Reaction Board Techniques for Estimating Inertial Properties of a Below-knee Prosthesis Body segmental inertial properties are required for inverse dynamics modeling. Using an oscillation and reaction board technique, inertial properties of below-knee prostheses were measured. Using direct measures of prosthesis inertia in the inverse dynamics model of the prosthetic leg resulted in lower magnitudes of resultant joint forces and moments. https://www.jove.com/v/50977 488 2014-05-08T16:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53668.jpg Simulation of Human-induced Vibrations Based on the Characterized In-field Pedestrian Behavior A protocol is presented for the characterization of the in-field pedestrian behavior and the simulation of the resulting structural response. Field-tests demonstrate that the in situ identified pacing rate and synchronization rate among the participants constitute an essential input for the simulation and verification of the human-induced loads. https://www.jove.com/v/53668 652 2016-04-13T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56759.jpg Subject-specific Musculoskeletal Model for Studying Bone Strain During Dynamic Motion During landing, lower-body bones experience large mechanical loads and are deformed. It is essential to measure bone deformation to better understand the mechanisms of bone stress injuries associated with impacts. A novel approach integrating subject-specific musculoskeletal modeling and finite element analysis is used to measure tibial strain during dynamic movements. https://www.jove.com/v/56759 572 2018-04-11T12:30:00+00:00 JoVE no https://visualize.jove.com/10384652-medical-affective-computing-medical-informatics-meets-affective-computing monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12979.jpg Issues And Trends In Healthcare Delivery System The issues and trends in healthcare delivery are constantly changing. The COVID-19 pandemic is one recent issue that wreaked havoc on healthcare systems, causing a shortage of healthcare workers, high demand for medicines and supplies, and increased medical expenditure due to a lack of insurance. Other issues include rising healthcare costs and care fragmentation. Cost Containment Payment for healthcare services has historically promoted adoption of costly and often unnecessary or inefficient... https://www.jove.com/v/12979 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14125.jpg Health Information Technology and Healthcare Information System Health Information Technology (HIT) Health Information Technology, commonly called HIT, integrates advanced information systems and technology in healthcare settings. Its primary functions include: Documentation and Monitoring of Patient Care: HIT systems facilitate the efficient recording and tracking of patient data, aiding healthcare providers in monitoring patients' health status and making informed decisions. Managerial and Organizational Functions: Beyond patient care, HIT is... https://www.jove.com/v/14125 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17752.jpg Brain Imaging Brain imaging technologies provide critical insights into both the structure and function of the human brain, enabling medical professionals and researchers to diagnose, study, and treat neurological disorders or psychiatric disorders more effectively. These technologies include computerized axial tomography (CAT or CT scans), positron-emission tomography (PET scans), magnetic resonance imaging (MRI), functional magnetic resonance imaging (fMRI), and Transcranial Magnetic Stimulation (TMS).<br... https://www.jove.com/v/17752 74 JoVE no https://cloudfront.jove.com/files/ftp_upload/19924/19924_article_thumb_19924.jpg The Influence of Affect on Cognition Positive affect significantly influences cognitive processes, including evaluation, memory, creativity, and social judgments. Compared to negative affect, positive emotional states promote more favorable interpretations of stimuli, cognitive flexibility, and heuristic processing. These effects highlight emotions' powerful role in shaping how individuals perceive, remember, and interact with the world.Influence on Evaluation and AttributionWhen individuals experience positive affect, they are... https://www.jove.com/v/19924 89 2025-09-18T17:24:14+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19925/19925_article_thumb_19925.jpg The Influence of Cognition on Affect Cognition plays a pivotal role in shaping emotional experiences, as demonstrated by Schachter and Singer’s two-factor theory of emotion. According to this model, emotion arises from a combination of physiological arousal and cognitive interpretation. The body’s physiological response to stimuli is ambiguous and only gains emotional significance through cognitive labeling. For instance, an increased heart rate and adrenaline surge while standing near an attractive person may be interpreted as... https://www.jove.com/v/19925 89 2025-09-18T17:24:13+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19948/19948_article_thumb_19948.jpg Role of Affect in Interpersonal Attraction Affect plays a crucial role in shaping interpersonal evaluations and perceptions. Emotions influence how individuals judge and respond to others, often determining whether interactions are viewed positively or negatively. This effect can manifest directly through interactions with the person in question or indirectly via associations with unrelated emotional experiences.Direct Effects of Affect on AttractionAffect directly influences interpersonal attraction when a person’s behavior elicits... https://www.jove.com/v/19948 84 2025-09-18T17:23:55+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50942.jpg Assessment of Age-related Changes in Cognitive Functions Using EmoCogMeter, a Novel Tablet-computer Based Approach We tested the usability of a tablet-computer-based application (EmoCogMeter) in investigating the effects of age on cognition. Results show an age-related cognitive decline, thereby proving the usability of our application. Findings underline the great clinical and practical potential of a tablet-based application for detection and monitoring of cognitive dysfunction. https://www.jove.com/v/50942 613 2014-02-14T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59228.jpg Using Facial Electromyography to Assess Facial Muscle Reactions to Experienced and Observed Affective Touch in Humans We describe a protocol to assess facial muscle activity in response to experienced and observed tactile stimulation using facial electromyography. https://www.jove.com/v/59228 267 2019-03-15T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/69254.jpg Virtual Agent for Real-Time Motivational Interviewing by Integrating Adaptive Nonverbal Behavior and Language Models We present an open-source virtual agent platform for conducting real-time motivational interviews, combining state-of-the-art language and diffusion models to adapt to users' behavior and profile. Utilizing the Greta 2.0 platform, it supports various topics, including nutrition and sport-focused interventions, and offers a flexible, validated tool for enhancing digital therapeutic interactions. https://www.jove.com/v/69254 434 2025-12-23T22:15:00+00:00 JoVE no https://visualize.jove.com/10472329-modified-true-color-computer-assisted-image-analysis-versus-subjective-scoring-of-estrogen-receptor-expression-in-breast-cancer-a-comparison monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/53837.jpg Quantitation of Protein Expression and Co-localization Using Multiplexed Immuno-histochemical Staining and Multispectral Imaging Immunohistochemistry is a powerful lab technique for evaluating protein localization and expression within tissues. Current semi-automated methods for quantitation introduce subjectivity and often create irreproducible results. Herein, we describe methods for multiplexed immunohistochemistry and objective quantitation of protein expression and co-localization using multispectral imaging. https://www.jove.com/v/53837 520 2016-04-08T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57148.jpg Optimization of a Multiplex RNA-based Expression Assay Using Breast Cancer Archival Material Nucleic acid degradation in archival tissue, tumor heterogeneity, and a lack of fresh frozen tissue specimens can negatively impact cancer diagnostic services in pathology laboratories worldwide. This manuscript describes the optimization of a panel of biomarkers using a multiplex magnetic bead assay to classify breast cancers. https://www.jove.com/v/57148 672 2018-08-01T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61805.jpg Using Computer-based Image Analysis to Improve Quantification of Lung Metastasis in the 4T1 Breast Cancer Model We describe a more consistent and expeditious method to quantify lung metastasis in the 4T1 breast cancer model by using Fiji-ImageJ. https://www.jove.com/v/61805 512 2020-10-02T22:00:00+00:00 JoVE no https://visualize.jove.com/10493874-nuclear-localization-signal-recognition-causes-release-of-importin-alpha-from-aggregates-in-the-cytosol monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2040.jpg Single-Molecule Imaging of Nuclear Transport Single molecule microscopy approch provided novel insights into nuclear transport. https://www.jove.com/v/2040 733 2010-06-10T00:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/2488.jpg Heterokaryon Technique for Analysis of Cell Type-specific Localization A flexible and efficient method for the characterization of cell type-specific protein localization and nucleocytoplasmic shuttling is described. This heterokaryon approach uses fluorescently-labeled fusion proteins to image protein localizations after cell fusion. The protocol is amenable to steady-state localizations or more dynamic determinations based on live cell imaging. https://www.jove.com/v/2488 571 2011-03-11T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11589.jpg Nuclear Export of mRNA Before mRNAs are exported to the cytoplasm, it is crucial to check each mRNA for structural and functional integrity. Eukaryotic cells use several different mechanisms, collectively known as mRNA surveillance, to look for irregularities in mRNAs. Irregular or aberrant mRNA are rapidly degraded by various enzymes. If a defective mRNA escapes the surveillance, it would be translated into a protein which would either be non-functional or not function properly. One of the primary irregularities in... https://www.jove.com/v/11589 151 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11935.jpg Nuclear Protein Sorting Nuclear protein sorting is the selective trafficking of histones, polymerases, gene regulatory proteins into the nucleus and exporting RNAs and ribosomes to the cytosol. It is a tightly controlled process that regulates gene expression within a cell. Proteins targeted to the nucleus carry nuclear localization signals or NLS recognized by import receptors in the cytosol. Similarly, proteins with nuclear export signals are recognized by export receptors. Import and export receptors are... https://www.jove.com/v/11935 94 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11936.jpg Nuclear Localization Signals and Import Proteins targeted to the nucleus carry short stretches of amino acid sequences called the nuclear localization signal or NLS. Classical nuclear localization signals are of two types: monopartite and bipartite NLS. Monopartite classical NLS (cNLS) consists of a single cluster of 4-8 amino acids. Bipartite cNLS consists of two clusters of 2-3 amino acids and a 9-12 residue long proline-rich linker bridging the two clusters. Signal clusters are rich in positively charged amino acids such as... https://www.jove.com/v/11936 106 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11937.jpg Nuclear Export The nucleus restricts several proteins within and allows others to pass. The restricted proteins possess a nuclear retention sequence or NRS, anchoring them to the nuclear lamins and preventing their transport to the cytosol. The non-restricted proteins, after their synthesis, are transported to their site of action, such as the cytosol or other organelles, with the help of nuclear export signals or NES. NES are of three types- the canonical 10-residue long leucine-rich signal and other... https://www.jove.com/v/11937 102 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11938.jpg Directionality of Nuclear Transport Ras-related nuclear protein or Ran is a small G protein that cycles between its GTP and GDP bound states. Ran specific regulators, a Ran GTPase Activating Protein or RanGAP present in the cytosol and a Ran guanine nucleotide exchange factor or RanGEF present inside the nucleus regulate GTP/GDP exchange. A high concentration of GTP inside the cells, in addition to this asymmetric distribution of Ran-specific regulators, leads to a higher RanGTP concentration inside the nucleus. This... https://www.jove.com/v/11938 102 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11939.jpg Regulation of Nuclear Protein Sorting Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the... https://www.jove.com/v/11939 105 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51310.jpg Isolation of CA1 Nuclear Enriched Fractions from Hippocampal Slices to Study Activity-dependent Nuclear Import of Synapto-nuclear Messenger Proteins We provide a detailed protocol for induction of long-term potentiation in the CA1 region of the hippocampus and the subsequent isolation of nuclear enriched fractions from the tetanized area of the slice. This approach can be used to determine activity dependent nuclear protein import in cellular models of learning and memory. https://www.jove.com/v/51310 603 2014-08-10T21:00:00+00:00 JoVE no https://visualize.jove.com/10508151-crystal-structure-and-induction-mechanism-of-amic-amir-a-ligand-regulated-transcription-antitermination-complex monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4266.jpg Iterative Optimization of DNA Duplexes for Crystallization of SeqA-DNA Complexes Crystal structure of protein–DNA complexes can provide insight into protein function, mechanism, as well as, the nature of the specific interaction. Here, we report how to optimize the length, sequence and ends of duplex DNA for co-crystallization with Escherichia coli SeqA, a negative regulator of replication initiation. https://www.jove.com/v/4266 702 2012-11-01T22:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11608.jpg Cooperative Binding of Transcription Regulators Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome. Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form dimers that... https://www.jove.com/v/11608 133 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11612.jpg Co-activators and Co-repressors Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into... https://www.jove.com/v/11612 124 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11614.jpg Eukaryotic Transcription Inhibitors Certain biochemical processes, such as embryonic development and cell growth regulation, depend on the repression of specific genes. DNA binding proteins known as eukaryotic transcription inhibitors regulate the repression of gene expression in eukaryotes. The presence of these inhibitors at the required location and time in the cell is triggered by the presence of hormones and additional signals from other cells. Eukaryotic transcription inhibitors usually contain two distinct domains, a DNA... https://www.jove.com/v/11614 112 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11620.jpg Transcription Attenuation in Prokaryotes Transcriptional attenuation occurs when RNA transcription is prematurely terminated due to the formation of a terminator mRNA hairpin structure. Bacteria use these hairpins to regulate the transcription process and control the synthesis of several amino acids including histidine, lysine, threonine, and phenylalanine. Transcription attenuation takes place in the non-coding regions of mRNA. There are several different mechanisms used to attenuate transcription. In ribosome mediated... https://www.jove.com/v/11620 162 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12224.jpg Bacterial Transcription RNA polymerase (RNAP) carries out DNA-dependent RNA synthesis in both bacteria and eukaryotes. Bacteria do not have a membrane-bound nucleus. So, transcription and translation occur simultaneously, on the same DNA template. Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are: Initiation, which involves two specific sequences 10 and 35 base pairs upstream of the gene, which are called promoters. Elongation, where the... https://www.jove.com/v/12224 113 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11608.jpg Cooperative Binding of Transcription Regulators Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome. Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form dimers that... https://www.jove.com/v/13144 133 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58222.jpg Repressing Gene Transcription by Redirecting Cellular Machinery with Chemical Epigenetic Modifiers Regulation of the chromatin environment is an essential process required for proper gene expression. Here, we describe a method for controlling gene expression through the recruitment of chromatin-modifying machinery in a gene-specific and reversible manner. https://www.jove.com/v/58222 628 2018-09-20T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63147.jpg CD Spectroscopy to Study DNA-Protein Interactions The interaction of an ATP-dependent chromatin remodeler with a DNA ligand is described using CD spectroscopy. The induced conformational changes on a gene promoter analyzed by the peaks generated can be used to understand the mechanism of transcriptional regulation. https://www.jove.com/v/63147 408 2022-02-10T22:00:00+00:00 JoVE no https://visualize.jove.com/10526093-intracellular-atp-depletion-inhibits-swelling-induced-d-3haspartate-release-from-primary-astrocyte-cultures monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40939/40939_article_thumb_40939.jpg Cytotoxic Edema: Pathophysiology Cytotoxic edema is a form of cerebral edema characterized by intracellular swelling of neurons, astrocytes, and other glial cells. It develops when the mechanisms responsible for maintaining ionic gradients across the cell membrane become impaired. Under normal physiological conditions, the sodium–potassium ATPase actively transports sodium ions out of the cell and potassium ions into the cell, preserving osmotic balance and enabling electrical signaling. This pump requires a continuous supply... https://www.jove.com/v/40939 81 2026-04-13T23:56:06+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51322.jpg A Rapid and Specific Microplate Assay for the Determination of Intra- and Extracellular Ascorbate in Cultured Cells Ascorbate plays numerous important roles in cellular metabolism, many of which have only come to light in recent years. Here we describe a medium-throughput, specific and inexpensive microplate assay for the determination of both intra- and extracellular ascorbate in cell culture. https://www.jove.com/v/51322 716 2014-04-12T05:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51458.jpg Inducing Plasticity of Astrocytic Receptors by Manipulation of Neuronal Firing Rates Here we describe an adaptation of protocols used to induce homeostatic plasticity in neurons for the study of plasticity of astrocytic G protein-coupled receptors. Recently used to examine changes in astrocytic group I mGluRs in juvenile mice, the method can be applied to measure scaling of various astrocytic GPCRs, in tissue from adult mice in situ and in vivo, and to gain a better appreciation of the sensitivity of astrocytic receptors to changes in neuronal activity. https://www.jove.com/v/51458 767 2014-03-21T02:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63483.jpg Primary Cultures of Rat Astrocytes and Microglia and Their Use in the Study of Amyotrophic Lateral Sclerosis We present here a protocol on how to prepare primary cultures of glial cells, astrocytes, and microglia from rat cortices for time-lapse video imaging of intracellular Ca2+ for research on pathophysiology of amyotrophic lateral sclerosis in the hSOD1G93A rat model. https://www.jove.com/v/63483 576 2022-06-23T19:30:00+00:00 JoVE no https://visualize.jove.com/10543419-a-smart-room-for-hospitalised-elderly-people-essay-of-modelling-and-first-steps-of-an-experiment monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13107.jpg Hospitals-II Hospitals provide inpatient and outpatient services. Inpatient services provide care to patients that stay in the hospital for an extended period, ranging from days to months. Examples of inpatient services include intensive care units, hospital wards, or surgeries. Outpatient services provide care to patients who come to a hospital for a diagnostic or treatment but do not stay overnight —for example, diagnostic tests, surgical procedures, or health education. Nurses that work in hospitals have... https://www.jove.com/v/13107 59 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14124.jpg Documentation in Long-Term and Home Healthcare Setting Documentation in long-term care facilities and home healthcare settings is crucial for ensuring continuous, coordinated, and comprehensive care for patients. Each setting has its specific documentation processes and tools: Long-Term Care Facilities • Purpose: Documentation in long-term care facilities is critical for interprofessional resident assessment and planning. It ensures that all aspects of a resident's care - from medical needs to daily living assistance - are thoroughly monitored... https://www.jove.com/v/14124 89 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56942.jpg Methodology for Establishing a Community-Wide Life Laboratory for Capturing Unobtrusive and Continuous Remote Activity and Health Data Unobtrusive sensors and pervasive computing technology incorporated into the daily home life of older adults enables meaningful health and activity changes to be recorded continuously for months to years, providing ecologically valid, high frequency, multi-domain data for research or clinical use. https://www.jove.com/v/56942 681 2018-07-27T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58009.jpg Automated, Long-term Behavioral Assay for Cognitive Functions in Multiple Genetic Models of Alzheimer's Disease, Using IntelliCage This paper describes a protocol for cognitive assessments for genetic models of the Alzheimer's disease using the IntelliCage system, which is a high throughput automated behavioral monitoring system with operant conditioning. https://www.jove.com/v/58009 406 2018-08-04T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58823.jpg Multi-Modal Home Sleep Monitoring in Older Adults Here, we present a protocol to improve the quality of data from home sleep testing by providing a method to enhance instructions through a structured participant visit. This protocol includes the implementation of a step-by-step educational manual with photos to ensure proper placement of equipment. https://www.jove.com/v/58823 460 2019-01-26T22:00:00+00:00 JoVE no https://visualize.jove.com/10582448-brief-report-of-working-group-opd-ca-children-and-adolescents-axis-iv-structural-standard monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10981.jpg Sex Linked Disorders Like autosomes, sex chromosomes contain a variety of genes necessary for normal body function. When a mutation in one of these genes results in biological deficits, the disorder is considered sex-linked. Y chromosome mutations are called “Y-linked” and only affect males since they alone carry a copy of that chromosome. Mutations to the relatively small Y chromosome can impact male sexual function and secondary sex characteristics. Y-chromosome infertility is a disorder that affects sperm... https://www.jove.com/v/11982 103 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18600.jpg Introduction to Psychological Disorders Abnormal behavior, often referred to as mental illness, results from changes in brain function that influence thought patterns, behaviors, and social interactions. Psychologists and psychiatrists typically assess abnormal behavior using three primary criteria: deviance, maladaptation, and personal distress, particularly when these traits persist over long periods. Deviant Behavior Deviance in behavior refers to actions or thought patterns that significantly diverge from societal norms or... https://www.jove.com/v/18600 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18602.jpg Diagnostic and Statistical Manual of Mental Disorders (DSM) The Diagnostic and Statistical Manual of Mental Disorders (DSM) serves as the primary classification system for mental health disorders, providing standardized diagnostic criteria for clinicians and researchers. First published by the American Psychiatric Association (APA) in 1952, the DSM has undergone several revisions to reflect evolving psychiatric understanding. The fifth edition, DSM-5, released in 2013, introduced key updates that expanded diagnostic categories and modified diagnostic... https://www.jove.com/v/18602 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18620.jpg Treatment Strategies for Psychological Disorders Treatment approaches for psychological disorders fall into three main categories: psychological, biological, and sociocultural. Each approach targets different aspects of mental health, requiring varying levels of education and training. Psychological therapies focus on modifying emotions, thoughts, and behaviors through talking, interpreting, listening, rewarding, challenging, and modeling. Clinical psychologists, counselors, and social workers commonly practice psychotherapy. Clinical... https://www.jove.com/v/18620 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18627.jpg Modeling in Therapy Modeling, a key technique in therapy, uses observational learning to help clients acquire and practice new skills by watching therapists demonstrate desired behaviors. This approach, rooted in Albert Bandura's concept of vicarious learning, plays a significant role in therapeutic interventions for various psychological conditions, including social anxiety, ADHD, and depression. Participant Modeling Participant modeling involves therapists demonstrating calm and effective behaviors in situations... https://www.jove.com/v/18627 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/19612.jpg Oppositional Defiant Disorder A persistent pattern of angry or irritable mood, defiant behavior, or vindictiveness characterizes Oppositional Defiant Disorder (ODD). Symptoms must occur over at least six months, involve interactions with individuals beyond siblings, and meet specific diagnostic criteria to be clinically significant. The disorder affects emotional regulation, social interactions, and behavior, often manifesting early in life and influencing long-term development and functioning. Diagnostic Criteria and... https://www.jove.com/v/19612 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56111.jpg Use of a Psychophysiological Script-driven Imagery Experiment to Study Trauma-related Dissociation in Borderline Personality Disorder We present a protocol of personalized script-driven trauma-related imagery and clinical assessments within a comparison design for investigating peritraumatic dissociation (PD), psychophysiological reactions, i.e. heart rate (HR) and skin conductance (SC), and psychological features of often severely traumatized individuals with borderline personality disorder (BPD). https://www.jove.com/v/56111 595 2018-03-08T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60187.jpg The Adventures of Fundi Intervention Based on the Cognitive and Emotional Processing in Attention Deficit Hyperactive Disorder Patients This protocol illustrates a remedial therapy based on inductive learning and indirect communication (Ericksonian metaphorical hypnosis) that can be applied to children with Attention Deficit Hyperactive Disorder (ADHD). Particularly, this protocol is intended to test the effectiveness of a go/no-go decision task. Neuroscientific rationale is presented throughout the text. https://www.jove.com/v/60187 348 2020-06-12T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67770.jpg Polar Histogram Visualization of Acute Stress Disorder Scale Scores for Comprehensive Clinical Assessment This study introduces a novel polar histogram visualization method for analyzing Acute Stress Disorder Scale (ASDS) scores, focusing on elderly ICU caregivers. The technique displayed all 19 ASDS variables simultaneously, revealing distinct stress patterns between healthy controls and caregivers while demonstrating significant improvements post-intervention in hyperarousal and avoidance symptoms. https://www.jove.com/v/67770 505 2024-12-06T23:00:00+00:00 JoVE no https://visualize.jove.com/10592262-aminoacyl-trna-synthetases-database-y2k monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2007.jpg Genome-wide Analysis of Aminoacylation (Charging) Levels of tRNA Using Microarrays We describe a method for microarray analysis to determine relative aminoacylation levels of all tRNAs from S. cerivisiae. https://www.jove.com/v/2007 452 2010-06-19T00:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/2498.jpg Isolation of Translating Ribosomes Containing Peptidyl-tRNAs for Functional and Structural Analyses A major impediment to biochemical analyses of ribosomes containing nascent peptidyl-tRNAs has been the presence of other ribosomes in the same samples, ribosomes not involved in the translation of the specific mRNA sequence being analyzed. We developed a simple methodology to purify, exclusively, the ribosomes containing the nascent peptidyl-tRNA of interest. https://www.jove.com/v/2498 679 2011-02-26T00:03:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11591.jpg Transfer RNA Synthesis One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases. Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with... https://www.jove.com/v/11591 156 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11595.jpg tRNA Activation Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the... https://www.jove.com/v/11595 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11597.jpg Improving Translational Accuracy Base complementarity between the three base pairs of mRNA codon and the tRNA anticodon is not a failsafe mechanism. Inaccuracies can range from a single mismatch to no correct base pairing at all. The free energy difference between the correct and nearly correct base pairs can be as small as 3 kcal/ mol. With complementarity being the only proofreading step, the estimated error frequency would be one wrong amino acid in every 100 amino acids incorporated. However, error frequencies observed in... https://www.jove.com/v/11597 127 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12221.jpg Allosteric Proteins-ATCase Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor. Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,... https://www.jove.com/v/12221 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11591.jpg Transfer RNA Synthesis One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases. Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with... https://www.jove.com/v/12569 156 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11595.jpg tRNA Activation Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the... https://www.jove.com/v/13132 146 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68003.jpg Application of I TASSER, trRosetta, UCSF Chimera, HADDOCK server, and HEX loria for De Novo and In Silico Design of Proteins Protein design involves the construction of amino acid sequences and the incorporation of specific motifs to create functional variants. This approach is critical for the development of antimicrobial peptides (AMPs) to combat antibiotic-resistant pathogens. This paper presents a procedure for protein construction using various bioinformatics tools. https://www.jove.com/v/68003 308 2025-07-08T20:00:00+00:00 JoVE no https://visualize.jove.com/10600659-modulation-of-the-intrahepatic-renin-angiotensin-system-after-stimulation-of-the-gastric-sodium-monitor-in-the-rat monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10893.jpg Hormonal Regulation The renin-aldosterone system is an endocrine system which guides the renal absorption of water and electrolytes, thus managing blood pressure and osmoregulation. Activation of the system begins in the kidneys with a small cluster of cells adjacent to the afferent and efferent blood vessels of the renal corpuscle. As the nephrons are filtering blood, juxtaglomerular cells monitor blood pressure. If they detect a decrease in pressure, they release the hormone renin into the bloodstream. <br... https://www.jove.com/v/10893 93 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15023.jpg Antihypertensive Drugs: Angiotensin-Converting Enzyme Inhibitors Angiotensin-converting enzyme (ACE), a vital component of the renin-angiotensin-aldosterone system, is abundant in lung endothelial cells. ACE converts the inactive decapeptide, angiotensin I, into the active octapeptide, angiotensin II. This potent vasoconstrictor narrows blood vessels, increasing resistance to blood flow and elevating blood pressure. Angiotensin II also stimulates aldosterone production, encouraging kidney cells to reabsorb more sodium and water from urine, thereby increasing... https://www.jove.com/v/15023 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15025.jpg Antihypertensive Drugs: Direct Renin Inhibitors The renin-angiotensin-aldosterone system (RAAS) is an intricate physiological pathway involving numerous enzymes and hormones, including renin, angiotensin-converting enzyme (ACE), angiotensin I and II, and aldosterone. Imbalances within this system increase the production of angiotensin II and aldosterone. Increased angiotensin II levels promote vasoconstriction and blood pressure elevation. Concurrently, higher aldosterone levels stimulate sodium and water reabsorption in the kidneys,... https://www.jove.com/v/15025 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15037.jpg Heart Failure Drugs: Inhibitors of Renin-Angiotensin System The activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) contributes to cardiac remodeling, and inhibiting the RAAS is a pharmacological target in heart failure management. As a result, neurohumoral modulation is a crucial treatment principle for managing heart failure. This approach involves using medications like ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), β-blockers, mineralocorticoid receptor antagonists (MRAs), and neutral... https://www.jove.com/v/15037 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15301.jpg Neural Regulation of Blood Pressure The neural regulation of blood pressure involves intricate interactions between the autonomic nervous system (ANS) and cardiovascular system, ensuring adequate perfusion of tissues. This regulation primarily occurs through baroreceptor and chemoreceptor reflexes, involving both short-term and long-term mechanisms. Baroreceptor Reflex Baroreceptors, located in the carotid sinuses and aortic arch, detect changes in blood pressure. When blood pressure rises, these stretch-sensitive receptors... https://www.jove.com/v/15301 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16251.jpg Glomerular Filtration Rate and its Regulation The Glomerular Filtration Rate (GFR) is a measure of kidney function, reflecting the volume of filtrate formed per minute in the kidneys. On average, GFR is approximately 125 mL/min in males and 105 mL/min in females. Maintaining a relatively constant GFR is essential for the kidneys to effectively regulate body fluid homeostasis and maintain extracellular stability. GFR regulation involves two primary intrinsic controls: the myogenic and tubuloglomerular feedback mechanisms. The myogenic... https://www.jove.com/v/16251 88 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56133.jpg Evaluation of Vascular Control Mechanisms Utilizing Video Microscopy of Isolated Resistance Arteries of Rats This manuscript describes in vitro video microscopy protocols for evaluating vascular function in rat cerebral resistance arteries. The manuscript also describes techniques for evaluating microvessel density with fluorescently labeled lectin and tissue perfusion using Laser Doppler Flowmetry. https://www.jove.com/v/56133 628 2017-12-05T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58205.jpg Quantifying Acute Changes in Renal Sympathetic Nerve Activity in Response to Central Nervous System Manipulations in Anesthetized Rats Methods for measuring sympathetic and cardiovascular responses to central nervous system (CNS) manipulations are important for advancing neuroscience. This protocol was developed to assist scientists with measuring and quantifying acute changes in renal sympathetic nerve activity (RSNA) in anesthetized rats (non-survival). https://www.jove.com/v/58205 390 2018-09-11T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61058.jpg A Modified Two Kidney One Clip Mouse Model of Renin Regulation in Renal Artery Stenosis A modified 2 kidney 1 clip (2K1C) Goldblatt mouse model was developed using polyurethane tubing to initiate renal artery stenosis, inducing an increase in renin expression and kidney injury. Here, we describe a detailed procedure of preparing and placing the cuff onto the renal artery to generate a reproducible and consistent 2K1C mouse model. https://www.jove.com/v/61058 501 2020-10-26T20:00:00+00:00 JoVE no https://visualize.jove.com/10601469-pattern-generation-in-the-buccal-system-of-freely-behaving-lymnaea-stagnalis monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4320.jpg An In Vitro Preparation for Eliciting and Recording Feeding Motor Programs with Physiological Movements in Aplysia californica We describe a technique to extracellularly record and stimulate from nerves, muscles, and individual identified neurons in vitro while eliciting and observing different types of feeding behaviors in the feeding apparatus of Aplysia. https://www.jove.com/v/4320 709 2012-12-05T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10919.jpg Fixed Action Patterns A fixed action pattern (FAP) is a specific, hard-wired sequence of behaviors that occurs in response to an external stimulus, called a sign stimulus. The behavior is “fixed” because it is essentially unchangeable—proceeding similarly across individuals of a species every time it occurs. Three-Spined Sticklebacks A classic example of a FAP was described in three-spined stickleback fish by Nikolaas Tinbergen in the 1930s. During the breeding season, the male fish develop a red throat and belly... https://www.jove.com/v/10919 66 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11539.jpg Lampbrush Chromosomes In 1882, Flemming observed lampbrush chromosomes (LBC) in salamander eggs. Later in 1892, Rückert observed LBCs in shark egg cells and coined the term "lampbrush chromosomes" because they looked like brushes used to clean kerosene lamps. LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops resemble the... https://www.jove.com/v/11539 111 JoVE no https://cloudfront.jove.com/files/ftp_upload/19854/19854_article_thumb_19854.jpg Diversity of Protists IV Amoebozoa represent a diverse group of terrestrial and aquatic protists that utilize lobe-shaped pseudopodia for locomotion and feeding. This characteristic differentiates them from the Rhizaria, which possess threadlike pseudopodia. The primary classifications within Amoebozoa include gymnamoebas, entamoebas, and the plasmodial and cellular slime molds. Phylogenetic evidence indicates that Amoebozoa diverged from a lineage that ultimately gave rise to fungi and animals.Gymnamoebas and... https://www.jove.com/v/19854 87 2025-06-05T13:27:20+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51075.jpg Aplysia Ganglia Preparation for Electrophysiological and Molecular Analyses of Single Neurons Marine snail Aplysia californica has been widely used as a neurobiology model for the studies on cellular and molecular basis of behavior. Here a methodology is described for exploring the nervous system of Aplysia for the electrophysiological and molecular analyses of single neurons of identified neural circuitry. https://www.jove.com/v/51075 551 2014-01-13T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53968.jpg A Whole Mount In Situ Hybridization Method for the Gastropod Mollusc Lymnaea stagnalis The goal of this protocol is to provide users with a set of methods for the high-throughput decapsulation of Lymnaea stagnalis embryos and larvae in preparation for whole mount in situ hybridization, and for subsequent pre- and post-hybridization treatments. https://www.jove.com/v/53968 453 2016-03-15T22:00:00+00:00 JoVE no https://visualize.jove.com/10648952-design-observation-surprise-a-test-of-emergence monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11020.jpg Naturalistic Observations If you want to understand how behavior occurs, one of the best ways to gain information is to simply observe the behavior in its natural context. However, people might change their behavior in unexpected ways if they know they are being observed. How do researchers obtain accurate information when people tend to hide their natural behavior? As an example, imagine that your professor asks everyone in your class to raise their hand if they always wash their hands after using the restroom. Chances... https://www.jove.com/v/11020 150 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13574.jpg Unusual Results Unusual results are those that have a very low chance of occurring. Unusual results can be identified using probabilities and the range rule of thumb. In problems involving probability, unusual results can be observed in 2 instances – an unusually high number of successes or an unusually low number of successes. According to the range rule of thumb, any value above or below two standard deviations, 2σ from the mean, μ is considered unusual. Maximum unusual value = μ + 2σ Minimum unusual value... https://www.jove.com/v/13574 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13603.jpg Introduction to Test of Independence In statistics, the term independence means that one can directly obtain the probability of any event involving both variables by multiplying their individual probabilities. Tests of independence are chi-square tests involving the use of a contingency table of observed (data) values. The test statistic for a test of independence is similar to that of a goodness-of-fit test: where: O = observed values E = expected values (which should be at least 5) A test of independence determines whether... https://www.jove.com/v/13603 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13637.jpg Observational Studies Observational studies are a type of analytical study where researchers observe events without any interventions. In other words, the researcher does not influence the response variable or the experiment's outcome. There are three types of observational studies – Prospective, retrospective, and cross-sectional. Prospective Study Prospective studies, also known as longitudinal or cohort studies, are carried out by collecting future data from groups sharing similar characteristics. One example of... https://www.jove.com/v/13637 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13640.jpg Randomized Experiments The randomization process involves assigning study participants randomly to experimental or control groups based on their probability of being equally assigned. Randomization is meant to eliminate selection bias and balance known and unknown confounding factors so that the control group is similar to the treatment group as much as possible. A computer program and a random number generator can be used to assign participants to groups in a way that minimizes bias. Simple randomization Simple... https://www.jove.com/v/13640 73 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14084.jpg Experimental Designs An experimental design is a systematic process that allows researchers to evaluate the relationship between dependent and independent variables. There are three widely used types of experimental design - pre-experimental design, true experimental design, and quasi-experimental design. In pre-experimental design, the researcher compares the data before and after some interventions or treatments. The true-experimental design has more than one purposefully created group, a commonly measured... https://www.jove.com/v/14084 76 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56677.jpg A Method for Investigating Change Blindness in Pigeons ( Columba Livia ) Change blindness is a phenomenon of visual attention, whereby changes to a visual display go unnoticed under certain specific circumstances. This protocol describes a variation on the flicker paradigm for investigating change blindness that is appropriate and effective for research with pigeons. https://www.jove.com/v/56677 374 2018-09-07T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58086.jpg Using Eye Movements Recorded in the Visual World Paradigm to Explore the Online Processing of Spoken Language The visual world paradigm monitors participants' eye movements in the visual workspace as they are listening to or speaking a spoken language. This paradigm can be used to investigate the online processing of a wide range of psycholinguistic questions, including semantically complex statements, such as disjunctive statements. https://www.jove.com/v/58086 567 2018-10-13T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60037.jpg A Cross-Disciplinary and Multi-Modal Experimental Design for Studying Near-Real-Time Authentic Examination Experiences An experimental design was developed to investigate the real-time influences of an examination experience to assess the emotional realities students experience in higher education settings and tasks. This design is the result of a cross-disciplinary (e.g., educational psychology, biology, physiology, engineering) and multi-modal (e.g., salivary markers, surveys, electrodermal sensor) approach. https://www.jove.com/v/60037 513 2019-09-04T21:00:00+00:00 JoVE no https://visualize.jove.com/10655471-using-lateral-capillary-forces-to-compute-by-self-assembly monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12255.jpg Mechanism of Lamellipodia Formation Cells migrating in response to external stimuli form lamellipodia, which are thin membrane protrusions supported by a mesh of linked, branched, or unbranched actin filaments. These actin filaments interact with myosin motor proteins, creating the dynamic actomyosin complex within the cytoskeleton. Contractility, or the ability to generate contractile stress, is inherent to the actomyosin complex. It helps cells detect the stiffness of the surrounding ECM and exert contractile force for... https://www.jove.com/v/12255 91 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51143.jpg Fabrication and Visualization of Capillary Bridges in Slit Pore Geometry A procedure for creating and imaging capillary bridges in slit-pore geometry is presented. The creation of capillary bridges relies on the formation of pillars to provide a directional physical and chemical heterogeneity to pin the fluid. Capillary bridges are formed and manipulated using microstages and visualized using a CCD camera. https://www.jove.com/v/51143 680 2014-01-09T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54145.jpg Creating Sub-50 Nm Nanofluidic Junctions in PDMS Microfluidic Chip via Self-Assembly Process of Colloidal Particles We propose a simple self-assembly technique of silica colloidal nanoparticles to create a nanofluidic junction between two microchannels in polydimethylsiloxane (PDMS). Using this technique, a nanoporous bead membrane with a pore size down to ~45 nm was built inside a microchannel and applied to electrokinetic preconcentration of DNA samples. https://www.jove.com/v/54145 673 2016-03-13T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63131.jpg Patterning of Microorganisms and Microparticles through Sequential Capillarity-assisted Assembly We present a technology that uses capillarity-assisted assembly in a microfluidic platform to pattern micro-sized objects suspended in a liquid, such as bacteria and colloids, into prescribed arrays on a polydimethylsiloxane substrate. https://www.jove.com/v/63131 617 2021-11-04T20:00:00+00:00 JoVE no https://visualize.jove.com/10693967-angiotensin-ii-modulates-the-activity-of-nak-atpase-in-cultured-rat-astrocytes-via-the-at1-receptor-and-protein-kinase-c-delta-activation monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15020.jpg Antihypertensive Drugs: Action of β 1 Blockers β1-receptors are primarily located in the heart and kidneys. In cardiac myocytes, these receptors interact with neurotransmitters released by the sympathetic nervous system during heightened activity or danger. As a result, β1-receptors get activated, initiating a series of biochemical processes. Excessive activation of beta receptors due to chronic stress can abnormally increase heart rate and contractility, resulting in high blood pressure or hypertension. To counteract this, β1-blockers... https://www.jove.com/v/15020 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15023.jpg Antihypertensive Drugs: Angiotensin-Converting Enzyme Inhibitors Angiotensin-converting enzyme (ACE), a vital component of the renin-angiotensin-aldosterone system, is abundant in lung endothelial cells. ACE converts the inactive decapeptide, angiotensin I, into the active octapeptide, angiotensin II. This potent vasoconstrictor narrows blood vessels, increasing resistance to blood flow and elevating blood pressure. Angiotensin II also stimulates aldosterone production, encouraging kidney cells to reabsorb more sodium and water from urine, thereby increasing... https://www.jove.com/v/15023 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15024.jpg Antihypertensive Drugs: Angiotensin II Receptor Blockers In the renin-angiotensin-aldosterone system, a hormone called angiotensin II plays a crucial role. It binds to the AT1 receptors in vascular smooth muscles coupled with Gq proteins. The activation of these receptors activates an enzyme called phospholipase C, which releases two molecules: inositol trisphosphate and diacylglycerol. These molecules cause a chain reaction that leads to the phosphorylation of myosin light chains and promotes interaction between actin and myosin, leading to smooth... https://www.jove.com/v/15024 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15025.jpg Antihypertensive Drugs: Direct Renin Inhibitors The renin-angiotensin-aldosterone system (RAAS) is an intricate physiological pathway involving numerous enzymes and hormones, including renin, angiotensin-converting enzyme (ACE), angiotensin I and II, and aldosterone. Imbalances within this system increase the production of angiotensin II and aldosterone. Increased angiotensin II levels promote vasoconstriction and blood pressure elevation. Concurrently, higher aldosterone levels stimulate sodium and water reabsorption in the kidneys,... https://www.jove.com/v/15025 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15037.jpg Heart Failure Drugs: Inhibitors of Renin-Angiotensin System The activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) contributes to cardiac remodeling, and inhibiting the RAAS is a pharmacological target in heart failure management. As a result, neurohumoral modulation is a crucial treatment principle for managing heart failure. This approach involves using medications like ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), β-blockers, mineralocorticoid receptor antagonists (MRAs), and neutral... https://www.jove.com/v/15037 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/17966/17966_article_thumb_17966.jpg Hypertension II: Pathophysiology Hypertension is a chronic condition in which the blood's force against artery walls is excessively high, posing risks such as heart disease. The condition's underlying mechanisms involve complex interactions among the cardiovascular, kidney, and autonomic nervous systems.Renin-Angiotensin-Aldosterone System (RAAS): This system significantly influences blood pressure regulation. When blood pressure decreases, the kidneys secrete renin. This enzyme transforms angiotensinogen, a plasma protein,... https://www.jove.com/v/17966 89 2025-06-19T16:16:31+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52850.jpg Single-channel Analysis and Calcium Imaging in the Podocytes of the Freshly Isolated Glomeruli Changes in the intracellular calcium levels in the podocytes are one of the most important means to control the filtration function of glomeruli. Here we explain a high-throughput approach that allows detection of real-time calcium handling and single ion channels activity in the podocytes of the freshly isolated glomeruli. https://www.jove.com/v/52850 739 2015-06-27T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53035.jpg Implementing Patch Clamp and Live Fluorescence Microscopy to Monitor Functional Properties of Freshly Isolated PKD Epithelium Ion channels expressed in renal tubular epithelium play a significant role in the pathology of polycystic kidney disease. Here we describe experimental protocols used to perform patch-clamp analysis and intracellular calcium level measurements in cystic epithelium freshly isolated from rodent kidneys. https://www.jove.com/v/53035 526 2015-09-01T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53866.jpg Receptor Autoradiography Protocol for the Localized Visualization of Angiotensin II Receptors Here we present a protocol to describe the localization of angiotensin II Type 1 receptors in the rat brain by quantitative, densitometric, in vitro receptor autoradiography using an iodine-125 labeled analog of angiotensin II. https://www.jove.com/v/53866 723 2016-06-07T21:30:00+00:00 JoVE no https://visualize.jove.com/10731972-cytoprotective-effect-of-amifostine-in-children-during-induction-therapy-according-to-bfm-83-report-on-cases monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17217/17217_article_thumb_17217.jpg Extracorporeal Removal of Drugs: Hemoperfusion and Hemofiltration Hemoperfusion and hemofiltration are critical techniques in medical treatments to eliminate accumulated drugs, metabolites, and electrolytes from the bloodstream. These methods are particularly vital in cases of accidental poisoning and drug overdose.Hemoperfusion involves passing blood through an adsorbent material to remove unwanted substances. The main adsorbents used in hemoperfusion include activated charcoal and Amberlite resins. Activated charcoal can adsorb both polar and nonpolar... https://app.jove.com/v/17217 85 359 2025-10-03T14:00:23+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17990/17990_article_thumb_17990.jpg Pulmonary Embolism II: Diagnostic Studies and Interprofessional Care Diagnosing Pulmonary EmbolismDiagnosing pulmonary embolism (PE) involves clinical assessment and advanced imaging tests. The preferred diagnostic tool is the spiral (helical) CT scan or CT angiography (CTA), which uses intravenous contrast media to visualize the pulmonary vasculature and identify emboli.A ventilation-perfusion (V/Q) scan is an alternative for patients unable to receive contrast media. This scan includes both perfusion and ventilation scanning. Perfusion scanning involves... https://app.jove.com/v/17990 89 714 2025-06-19T16:21:13+00:00 JoVE no https://visualize.jove.com/10774131-a-new-class-of-auditory-warning-signals-for-complex-systems-auditory-icons monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10853.jpg Hearing When we hear a sound, our nervous system is detecting sound waves—pressure waves of mechanical energy traveling through a medium. The frequency of the wave is perceived as pitch, while the amplitude is perceived as loudness. Sound waves are collected by the external ear and amplified as they travel through the ear canal. When sounds reach the junction between the outer and middle ear, they vibrate the tympanic membrane—the eardrum. The resulting mechanical energy causes the attached ossicles—a... https://www.jove.com/v/10853 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14970.jpg Auditory Pathway Auditory pathways constitute the complex neural circuits responsible for transmitting and interpreting auditory information from the peripheral auditory system to the brain. Sound waves are initially captured by the outer ear, funneled through the ear canal, and reach the tympanic membrane (eardrum). These vibrations are transmitted via the middle ear's ossicles to the inner ear's cochlea. When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking the... https://www.jove.com/v/14970 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16029.jpg Signal and System A signal x(t) is a set of data or a time function representing a variable of interest. Signals typically convey information about a phenomenon, such as atmospheric temperature, humidity, human voice, television images, a dog's bark, or birdsongs. More generally, a signal can be a function of more than one independent variable. For instance, images depend on horizontal and vertical positions and can be regarded as two-dimensional signals. However, this text will focus on one-dimensional signals... https://www.jove.com/v/16029 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16030.jpg Classification of Signals In signal processing, signals are classified based on various characteristics: continuous-time versus discrete-time, periodic versus aperiodic, analog versus digital, and causal versus noncausal. Each category highlights distinct properties crucial for understanding and manipulating signals. A continuous-time signal holds a value at every instant in time, representing information seamlessly. In contrast, a discrete-time signal holds values only at specific moments, often denoted as x(n), where... https://www.jove.com/v/16030 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17771.jpg Auditory Perception The auditory system is essential for sound perception, utilizing various critical structures. When sound waves enter the outer ear, they travel through the ear canal and cause the eardrum to vibrate. These vibrations are then transmitted to the middle ear, where three tiny bones – the malleus, incus, and stapes – amplify the sound. This amplification is crucial, as it ensures that the sound vibrations are strong enough to be conveyed to the inner ear. These vibrations then reach the cochlea, a... https://www.jove.com/v/17771 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17772.jpg Perceiving Loudness, Pitch, and Location The human brain perceives pitch through two primary mechanisms reflected in place theory and frequency theory. Each mechanism describes how sound waves are interpreted as specific pitches by the brain, offering insights into the intricate processes of auditory perception. Place theory, or place coding, suggests that different pitches are heard because various sound waves activate specific locations along the cochlea's basilar membrane. The brain determines the pitch of a sound by identifying... https://www.jove.com/v/17772 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50027.jpg A Lightweight, Headphones-based System for Manipulating Auditory Feedback in Songbirds We describe the design and assembly of miniaturized headphones suitable for replacing a songbird’s natural auditory feedback with a manipulated acoustic signal. Online sound processing hardware is used to manipulate song output, introduce real-time errors in auditory feedback via the headphones, and drive vocal motor learning. https://www.jove.com/v/50027 613 2012-11-26T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61408.jpg Tactile Vibrating Toolkit and Driving Simulation Platform for Driving-Related Research This protocol describes a driving simulation platform and a tactile vibrating toolkit for the investigation of driving-related research. An exemplar experiment exploring the effectiveness of tactile warnings is also... https://www.jove.com/v/61408 435 2020-12-18T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/70048.jpg An Automated System for Sound Localization Testing in Hearing-Impaired Listeners This protocol introduces an automated sound localization testing system with precise loudspeaker placement and integrated response analysis, validated in normal-hearing participants and participants with single-sided deafness. It provides a reproducible method to assess spatial hearing and supports functional classification using the International Classification of Functioning, Disability and Health (ICF) framework. https://www.jove.com/v/70048 472 2026-03-13T13:50:00+00:00 JoVE no https://visualize.jove.com/10778751-the-effects-of-transcription-and-rna-processing-on-the-initiation-of-chloroplast-dna-replication-in-chlamydomonas-reinhardtii monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10789.jpg Replication in Eukaryotes Overview In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus. Many Proteins Orchestrate Replication at the Origin Eukaryotic replication follows many of the... https://www.jove.com/v/10789 151 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11559.jpg Export of Mitochondrial and Chloroplast Genes A eukaryotic cell can have up to three different types of genetic systems: nuclear, mitochondrial, and chloroplast. During evolution, organelles have exported many genes to the nucleus; this transfer is still ongoing in some plant species. Approximately 18% of the Arabidopsis thaliana nuclear genome is thought to be derived from the chloroplast’s cyanobacterial ancestor, and around 75% of the yeast genome derived from the mitochondria’s bacterial ancestor. This export has occurred irrespective... https://www.jove.com/v/11559 139 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11585.jpg Transcription Elongation Factors Transcription elongation is a dynamic process that alters depending upon the sequence heterogeneity of the DNA being transcribed. Hence, it is not surprising that the elongation complex's composition also varies along the way while transcribing a gene. The transcription elongation is regulated via pausing of RNA polymerase on several occasions during transcription. In bacteria, these halts are necessary because the transcription of DNA into mRNA is coupled to the translation of that mRNA into a... https://www.jove.com/v/11585 155 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11588.jpg Chromatin Structure Regulates pre-mRNA Processing In eukaryotic cells, nascent mRNA transcripts need to undergo many post-transcriptional modifications to reach the cell cytoplasm and translate into functional proteins. For a long time, transcription and pre-mRNA processing were considered two independent events that occur sequentially in the cell. However, it has now been well established that transcription and pre-mRNA processing are two simultaneous processes that are precisely regulated inside the cell. The chromatin structure, especially... https://www.jove.com/v/11588 161 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12224.jpg Bacterial Transcription RNA polymerase (RNAP) carries out DNA-dependent RNA synthesis in both bacteria and eukaryotes. Bacteria do not have a membrane-bound nucleus. So, transcription and translation occur simultaneously, on the same DNA template. Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are: Initiation, which involves two specific sequences 10 and 35 base pairs upstream of the gene, which are called promoters. Elongation, where the... https://www.jove.com/v/12224 113 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13196.jpg Replication in Eukaryotes In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fulfill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus. Many Proteins Orchestrate Replication at the Origin Eukaryotic replication follows many of the same... https://www.jove.com/v/13196 89 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54831.jpg High-Throughput Robotically Assisted Isolation of Temperature-sensitive Lethal Mutants in Chlamydomonas reinhardtii Temperature-sensitive (ts) lethal mutants are valuable tools to identify and analyze essential functions. Here we describe methods to generate and classify ts lethal mutants in high throughput. https://www.jove.com/v/54831 651 2016-12-05T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59687.jpg Application of Biolayer Interferometry (BLI) for Studying Protein-Protein Interactions in Transcription Interactions of transcription factors (TFs) with the RNA polymerase are usually studied using pulldown assays. We apply a Biolayer Interferometry (BLI) technology to characterize the interaction of GrgA with the chlamydial RNA polymerase. Compared to pulldown assays, BLI detects real-time association and dissociation, offers higher sensitivity, and is highly quantitative. https://www.jove.com/v/59687 438 2019-07-26T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60019.jpg Discrimintion and Mapping of the Primary and Processed Transcripts in Maize Mitochondrion Using a Circular RT-PCR-based Strategy We present a circular RT-PCR-based strategy by combining circular RT-PCR, quantitative RT-PCR, RNA 5' polyphosphatase-treatment, and Northern blot. This protocol includes a normalization step to minimize the influence of unstable 5' triphosphate, and it is suitable for discriminating and mapping the primary and processed transcripts stably accumulated in maize mitochondrion. https://www.jove.com/v/60019 446 2019-07-29T22:00:00+00:00 JoVE no https://visualize.jove.com/10790942-the-australian-national-death-index-an-assessment-of-accuracy monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2597.jpg Modified Annexin V/Propidium Iodide Apoptosis Assay For Accurate Assessment of Cell Death An accurate method for the assessment of cell death is described. The protocol improves upon conventional Annexin V/ propidium iodide (PI) protocols, which display up to 40% false- positive events in cell lines and primary cells from a broad range of animal models. https://www.jove.com/v/2597 454 2011-04-24T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17615.jpg Life Tables A life table is a statistical tool that summarizes the mortality and survival patterns of a population, providing detailed insights into the likelihood of survival or death across different age intervals within a cohort. By organizing data on survival probabilities and mortality rates, life tables offer a clear snapshot of population dynamics over time. They are extensively used in demography, public health, actuarial science, and ecology to analyze life expectancy, design health interventions,... https://www.jove.com/v/17615 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17617.jpg Actuarial Approach The actuarial approach, a statistical method originally developed for life insurance risk assessment, is widely used to calculate survival rates in clinical and population studies. This method accounts for participants lost to follow-up or those who die from causes unrelated to the study, ensuring a more accurate representation of survival probabilities. Consider the example of a high-risk surgical procedure with significant early-stage mortality. A two-year clinical study is conducted,... https://www.jove.com/v/17617 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17618.jpg Kaplan-Meier Approach The Kaplan-Meier estimator is a non-parametric method used to estimate the survival function from time-to-event data. In medical research, it is frequently employed to measure the proportion of patients surviving for a certain period after treatment. This estimator is fundamental in analyzing time-to-event data, making it indispensable in clinical trials, epidemiological studies, and reliability engineering. By estimating survival probabilities, researchers can evaluate treatment effectiveness,... https://www.jove.com/v/17618 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17619.jpg Assumptions of Survival Analysis Survival models analyze the time until one or more events occur, such as death in biological organisms or failure in mechanical systems. These models are widely used across fields like medicine, biology, engineering, and public health to study time-to-event phenomena. To ensure accurate results, survival analysis relies on key assumptions and careful study design. Survival Times Are Positively Skewed Survival times often exhibit positive skewness, unlike the normal distribution assumed in... https://www.jove.com/v/17619 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17622.jpg Applications of Life Tables Life tables are versatile across various fields, providing a quantitative basis for analyzing mortality and survival rates. Whether used by demographers, actuaries, epidemiologists, or sociologists, life tables offer valuable insights into the dynamics of life and death, facilitating informed decisions in public health, insurance, conservation, and beyond. Their broad applicability highlights the interconnectedness of demographic data with practical outcomes in everyday life and strategic... https://www.jove.com/v/17622 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17623.jpg Cancer Survival Analysis Cancer survival analysis focuses on quantifying and interpreting the time from a key starting point, such as diagnosis or the initiation of treatment, to a specific endpoint, such as remission or death. This analysis provides critical insights into treatment effectiveness and factors that influence patient outcomes, helping to shape clinical decisions and guide prognostic evaluations. A cornerstone of oncology research, survival analysis tackles the challenges of skewed, non-normally... https://www.jove.com/v/17623 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56713.jpg Scanning Skeletal Remains for Bone Mineral Density in Forensic Contexts Bone mineral density (BMD) is an important factor in understanding nutritional intake. For human skeletal remains, it is a useful metric to assess quality of life in both juveniles and adults, particularly in fatal starvation and neglect cases. This paper provides guidelines for scanning human skeletal remains for forensic purposes. https://www.jove.com/v/56713 476 2018-01-29T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59825.jpg Inverse Probability of Treatment Weighting (Propensity Score) using the Military Health System Data Repository and National Death Index When randomized controlled trials are not feasible, a comprehensive health care data source like the Military Health System Data Repository provides an attractive alternative for retrospective analyses. Incorporating mortality data from the national death index and balancing differences between groups using propensity weighting helps reduce biases inherent in retrospective designs. https://www.jove.com/v/59825 415 2020-01-08T20:00:00+00:00 JoVE no https://visualize.jove.com/10821700-structural-requirements-for-the-interdomain-linker-of-alpha-subunit-of-escherichia-coli-rna-polymerase monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4110.jpg High-throughput Purification of Affinity-tagged Recombinant Proteins We describe a method for the affinity-tagged purification of recombinant proteins using liquid-handling robotics. This method is generally applicable to the small-scale purification of soluble His-tagged proteins in a high-throughput format. https://www.jove.com/v/4110 464 2012-08-26T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11579.jpg Bacterial RNA Polymerase Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity. In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize... https://www.jove.com/v/11579 43 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11583.jpg Eukaryotic RNA Polymerases RNA Polymerase (RNAP) is conserved in all animals, with bacterial, archaeal, and eukaryotic RNAPs sharing significant sequence, structural, and functional similarities. Among the three eukaryotic RNAPs, RNA Polymerase II is most similar to bacterial RNAP in terms of both structural organization and folding topologies of the enzyme subunits. However, these similarities are not reflected in their mechanism of action. All three eukaryotic RNAPs require specific transcription factors, of which the... https://www.jove.com/v/11583 58 2025-05-30T14:04:48+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11585.jpg Transcription Elongation Factors Transcription elongation is a dynamic process that alters depending upon the sequence heterogeneity of the DNA being transcribed. Hence, it is not surprising that the elongation complex's composition also varies along the way while transcribing a gene. The transcription elongation is regulated via pausing of RNA polymerase on several occasions during transcription. In bacteria, these halts are necessary because the transcription of DNA into mRNA is coupled to the translation of that mRNA into a... https://www.jove.com/v/11585 155 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12225.jpg Transcription Initiation Initiation is the first step of transcription in eukaryotes. Prokaryotic RNA Polymerase (RNAP) can bind to the template DNA and start transcribing. On the other hand, transcription in eukaryotes requires additional proteins, called transcription factors, to first bind to the promoter region in the DNA template. This binding helps recruit the specific RNAP that can assemble on the DNA and start transcription. The promoters and enhancers and their accessory proteins allow tight regulation of... https://www.jove.com/v/12225 107 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11579.jpg Bacterial RNA Polymerase Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity. In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize... https://www.jove.com/v/12559 43 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11583.jpg Eukaryotic RNA Polymerases RNA Polymerase (RNAP) is conserved in all animals, with bacterial, archaeal, and eukaryotic RNAPs sharing significant sequence, structural, and functional similarities. Among the three eukaryotic RNAPs, RNA Polymerase II is most similar to bacterial RNAP in terms of both structural organization and folding topologies of the enzyme subunits. However, these similarities are not reflected in their mechanism of action. All three eukaryotic RNAPs require specific transcription factors, of which the... https://www.jove.com/v/12560 58 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52431.jpg The Multifaceted Benefits of Protein Co-expression in Escherichia coli Protein co-expression is a powerful alternative to the reconstitution in vitro of protein complexes, and is of help in performing biochemical and genetic tests in vivo. Here we report on the use of protein co-expression in Escherichia coli to obtain protein complexes, and to tune the mutation frequency of cells. https://www.jove.com/v/52431 768 2015-02-05T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59497.jpg Artificial RNA Polymerase II Elongation Complexes for Dissecting Co-transcriptional RNA Processing Events Here, we describe the assembly of RNA polymerase II (Pol II) elongation complexes requiring only short synthetic DNA and RNA oligonucleotides and purified Pol II. These complexes are useful for studying mechanisms underlying co-transcriptional processing of transcripts associated with the Pol II elongation complex. https://www.jove.com/v/59497 659 2019-05-13T21:00:00+00:00 JoVE no https://visualize.jove.com/10833848-decomposition-of-posterior-alpha-rhythm monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14942.jpg Brain Waves Brain waves are electrical signals generated by the neurons in the brain, which are regularly monitored to measure mental activities. Brain waves and their frequency ranges can be measured using an electroencephalogram or EEG. There are four main types of brain waves, each with distinct characteristics: • Alpha Waves – Alpha brain waves, between 8 and 13 Hz ( Hertz), occur when a person is relaxed with eyes closed. The alpha waves then disappear when one is concentrating on specific tasks. <br... https://www.jove.com/v/14942 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12177.jpg Resting Potential Decay The resting membrane potential of a neuron (-70mV) is sustained due to the selective ion permeability of the membrane. At the resting potential, the membrane is slightly permeable to ions like sodium (Na+) and chloride (Cl−) and highly permeable to potassium ions (K+). Differences in the ions' concentration inside the cell compared to the outside are maintained by membrane transport proteins like channels and pumps. At rest, the K+ is the main ion that moves across the membrane through... https://www.jove.com/v/15001 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15275.jpg Correlation between ECG and Cardiac Cycle The electrical signals recorded on an electrocardiogram (ECG) occur before the mechanical processes of contraction and relaxation during the cardiac cycle. A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before... https://www.jove.com/v/15275 85 2025-05-15T16:16:28+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15276.jpg Disturbances in Heart Rhythm Arrhythmia or dysrhythmia refers to an abnormal heart rhythm caused by a defect in the heart's conduction system. It can cause the heart to beat irregularly, too quickly, or too slowly, leading to symptoms like chest pain, shortness of breath, and fainting. Factors such as stress, caffeine, alcohol, nicotine, cocaine, certain drugs, congenital defects, diseases, and electrolyte abnormalities can trigger arrhythmias. Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart... https://www.jove.com/v/15276 89 2025-07-29T16:29:05+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17878.jpg ECG Interpretation of Rhythms An electrocardiogram (ECG)graphically represents the heart's electrical activity on ECG paper or a monitor. Components of the Electrocardiogram The primary components of a normal ECG waveform in Normal sinus rhythm(NSR) include the P wave, PR interval, QRS complex, ST segment, T wave, and occasionally a U wave. ECG waveforms are divided by vertical and horizontal lines at standard intervals. The horizontal axis measures time and rate, and the vertical axis measures amplitude or voltage. When... https://www.jove.com/v/17878 84 JoVE no https://cloudfront.jove.com/files/ftp_upload/17941/17941_article_thumb_17941.jpg Dysrhythmias IV: Characteristics of Bradyarrhythmias Bradyarrhythmias are cardiac rhythm disorders characterized by a slower-than-normal heart rate, typically defined as fewer than 60 beats per minute. Some of which are discussed here:Sinus BradycardiaSinus bradycardia presents a heart rate lower than 60 beats per minute, with a regular rhythm originating from the SA node. The ECG typically shows normal P waves preceding each QRS complex, a normal PR interval (0.12 to 0.20 seconds), and a normal QRS duration (0.06 to 0.10 seconds).First-Degree AV... https://www.jove.com/v/17941 78 2025-06-19T16:36:24+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51412.jpg EEG Mu Rhythm in Typical and Atypical Development Assessment of the EEG mu rhythm provides a unique methodology for examining brain activity and when combined with behaviorally based assays, can be a powerful tool for elucidating aspects of social cognition, such as imitation, in clinical populations. https://www.jove.com/v/51412 710 2014-04-10T05:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56452.jpg Microstate and Omega Complexity Analyses of the Resting-state Electroencephalography This article describes the protocol underlying electroencephalography (EEG) microstate analysis and omega complexity analysis, which are two reference-free EEG measures and highly valuable to explore the neural mechanisms of brain disorders. https://www.jove.com/v/56452 400 2018-06-15T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62256.jpg Multi-system Monitoring for Identification of Seizures, Arrhythmias and Apnea in Conscious Restrained Rabbits Using simultaneous video-EEG-ECG-oximetry-capnography, we developed a methodology to evaluate the susceptibility of rabbit models to develop provoked arrhythmias and seizures. This novel recording system establishes a platform to test the efficacy and safety of therapeutics and can capture the complex cascade of multi-system events that culminate in sudden death. https://www.jove.com/v/62256 625 2021-03-27T20:00:00+00:00 JoVE no https://visualize.jove.com/10835360-distribution-of-acetylated-histones-resulting-from-gal4-vp16-recruitment-of-saga-and-nua4-complexes monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11532.jpg The Nucleosome Core Particle Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins. The paradox Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA... https://www.jove.com/v/11532 130 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11537.jpg Histone Modification The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression. Acetylation The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,... https://www.jove.com/v/11537 152 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11538.jpg Spreading of Chromatin Modifications The histone proteins in the nucleosomes are post-translationally modified (PTM) to increase or decrease access to DNA. The commonly observed PTMs are methylation, acetylation, phosphorylation, and ubiquitination of lysine amino acids in the histone H3 tail region. These histone modifications have specific meaning for the cell. Hence, they are called "histone code". The protein complex involved in histone modification is termed as "reader-writer" complex. Writers The writer is an enzyme that can... https://www.jove.com/v/11538 145 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11541.jpg Histone Variants at the Centromere Histone variants are the histone proteins with structural and sequence variations. These variants may be regarded as “mutant” forms that replace their canonical histone counterparts in the nucleosomes. Specific post-translational modifications on the histone variants enable further chromatin complexity and regulate tissue-specific gene expression. The most common histone variants are from histone H2A, H2B, and linker histone H1 families. However, several variants of histone H3 variants are also... https://www.jove.com/v/11541 150 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11537.jpg Histone Modification The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression. Acetylation The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,... https://www.jove.com/v/13187 152 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14746.jpg The Nucleosome Core Particle Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins. Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during... https://www.jove.com/v/14746 72 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57080.jpg Chromatin Immunoprecipitation (ChIP) of Histone Modifications from Saccharomyces cerevisiae Here, we describe a protocol for chromatin immunoprecipitation of modified histones from the budding yeast Saccharomyces cerevisiae. Immunoprecipitated DNA is subsequently used for quantitative PCR to interrogate the abundance and localization of histone post-translational modifications throughout the genome. https://www.jove.com/v/57080 666 2017-12-29T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58648.jpg Purification of H3 and H4 Histone Proteins and the Quantification of Acetylated Histone Marks in Cells and Brain Tissue The purpose of this article is to provide a comprehensive, systematic guide to the efficient purification of histones H3 and H4 and the quantification of acetylated histone residues. https://www.jove.com/v/58648 583 2018-11-30T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62113.jpg Site Specific Lysine Acetylation of Histones for Nucleosome Reconstitution using Genetic Code Expansion in Escherichia coli Here we present a method to express acetylated histone proteins using genetic code expansion and assemble reconstituted nucleosomes in vitro. https://www.jove.com/v/62113 446 2020-12-26T22:00:00+00:00 JoVE no https://visualize.jove.com/10852944-stochastic-focusing-fluctuation-enhanced-sensitivity-of-intracellular-regulation monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13327.jpg Feedback Regulation of Calcium Concentration Calcium is an essential signaling molecule required for various cellular functions. Calcium pumps and ion channels on cell and organellar membranes, such as those on the endoplasmic reticulum (ER), regulate calcium concentrations inside the cell. They remain closed, keeping the cytosolic calcium levels low at a resting state. Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs... https://www.jove.com/v/13327 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13395.jpg Protein Dynamics in Living Cells Different fluorescence-based techniques are used to study the protein dynamics in living cells. These techniques include FRAP, FRET, and PET. Fluorescent recovery after photobleaching (FRAP) is a fluorescent-protein-based detection technique used to quantify protein movement rates within the cell. This method exposes a small portion of the cell to an intense laser beam. The laser beam causes permanent photobleaching of the fluorophore-tagged proteins in the exposed region. As the bleached... https://www.jove.com/v/13395 79 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53912.jpg Measurement of Calcium Fluctuations Within the Sarcoplasmic Reticulum of Cultured Smooth Muscle Cells Using FRET-based Confocal Imaging Currently, most available calcium indicators are used to quantify cytoplasmic calcium transients as indirect measures of calcium released from the sarcoplasmic reticulum in cultured smooth muscle cells. This protocol describes the use of a specific FRET-based indicator that allows direct measurement of calcium signals within the sarcoplasmic reticulum lumen. https://www.jove.com/v/53912 605 2016-06-20T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58582.jpg A Fluorescence Fluctuation Spectroscopy Assay of Protein-Protein Interactions at Cell-Cell Contacts This protocol describes a fluorescence fluctuation spectroscopy-based approach to investigate interactions among proteins mediating cell-cell interactions, i.e. proteins localized in cell junctions, directly in living cells. We provide detailed guidelines on instrument calibration, data acquisition and analysis, including corrections to possible artefact sources. https://www.jove.com/v/58582 523 2018-12-01T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66275.jpg Estimation of Structural Sensitivity of Intrinsically Disordered Regions in Response to Hyperosmotic Stress in Living Cells Using FRET Intrinsically disordered regions (IDRs) are flexible protein domains that modify their conformation in response to environmental changes. Ensemble fluorescence resonance energy transfer (FRET) can estimate protein dimensions under different conditions. We present a FRET approach to assess IDR structural sensitivity in living Saccharomyces cerevisiae cells under hyperosmotic stress. https://www.jove.com/v/66275 313 2024-01-12T22:50:00+00:00 JoVE no https://visualize.jove.com/10853213-anaesthesia-and-fatigue-an-analysis-of-the-first-10-years-of-the-australian-incident-monitoring-study-1987-1997 monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3260.jpg Implantation of Radiotelemetry Transmitters Yielding Data on ECG, Heart Rate, Core Body Temperature and Activity in Free-moving Laboratory Mice A surgical technique for implantation of commercially available telemetry transmitters used for continuous measurement of biopotential (one-lead ECG), heart rate, core body temperature and locomotor activity in freely moving mice is shown. Recommendations and protocols for post-operative care and pain relief, improving recovery, well being and survival rate are also presented. https://www.jove.com/v/3260 551 2011-11-21T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14384.jpg Pharmacovigilance Post-marketing surveillance is a critical component of pharmaceutical regulation, often uncovering unanticipated adverse drug reactions (ADRs) once a drug is widely used over an extended period. This process, termed pharmacovigilance, aims to detect, evaluate, and minimize harmful effects related to medication use. The data collection for pharmacovigilance depends on spontaneous reporting systems, where healthcare professionals or patients voluntarily report suspected ADRs. In some cases, there... https://www.jove.com/v/14384 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15188.jpg General Anesthesia: Overview Anesthesia is a medical procedure that uses drugs for CNS suppression to enable painless surgeries and procedures. The selection of anesthetics is influenced by their pharmacokinetic properties, side effects, and patient characteristics. Various types of anesthesia include general, local, regional, spinal, and inhalational. General anesthesia induces unconsciousness in the whole body, while the others target specific areas or sensations. It is administered to minimize adverse effects, maintain... https://www.jove.com/v/15188 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15189.jpg Stages of General Anesthesia Various sedation levels offer significant advantages in facilitating procedural interventions for patients undergoing medical or invasive surgical procedures. These levels span from anxiolysis to general anesthesia, providing a spectrum of sedative effects to cater to specific patient needs. Anxiolysis reduces anxiety and is achieved through minimal sedation, enabling patients to remain awake and responsive while feeling more at ease during the procedure. This level can benefit minor... https://www.jove.com/v/15189 82 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56881.jpg Recording Brain Electromagnetic Activity During the Administration of the Gaseous Anesthetic Agents Xenon and Nitrous Oxide in Healthy Volunteers Simultaneous magnetoencephalography and electroencephalography provides a useful tool to search for common and distinct macro-scale mechanisms of reductions in consciousness induced by different anesthetics. This paper illustrates the empirical methods underlying the recording of such data from healthy humans during N-Methyl-D-Aspartate-(NMDA)-receptor-antagonist-based anesthesia during inhalation of nitrous oxide and xenon. https://www.jove.com/v/56881 892 2018-01-13T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59851.jpg Collecting Sleep, Circadian, Fatigue, and Performance Data in Complex Operational Environments Sleep loss and circadian misalignment contribute to numerous operational accidents and incidents. The effectiveness of countermeasures and work scheduling designs aimed at mitigating fatigue can be challenging to evaluate in operational environments. This manuscript summarizes an approach for collecting sleep, circadian, fatigue, and performance data in complex operational environments. https://www.jove.com/v/59851 516 2019-08-08T21:30:00+00:00 JoVE no https://visualize.jove.com/10854707-expression-of-leukemia-inhibitory-factor-lif-and-lif-receptor-lif-r-in-the-human-adrenal-cortex-implications-for-steroidogenesis monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10876.jpg Intracellular Hormone Receptors Lipid-soluble hormones diffuse across the plasma and nuclear membrane of target cells to bind to their specific intracellular receptors. These receptors act as transcription factors that regulate gene expression and protein synthesis in the target cell Based on their mode of action, intracellular hormone receptors are classified as Type I or Type II receptors. Type I receptors, including steroid hormone receptors such as the androgen receptor, are present in the cytoplasm. Hormone binding... https://www.jove.com/v/10876 68 2025-10-23T18:46:58+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14423.jpg Signal Transduction: Overview Cells respond to many types of information, often through receptor proteins positioned on the membrane. They respond to chemical signals, such as hormones, neurotransmitters, and other signaling molecules, initiating a series of molecular reactions to produce an appropriate response. This is called signal transduction. Cells also coordinate different responses elicited by the same signaling molecule via mediators, allowing molecular cross-talk. Typically, signal transduction involves three... https://www.jove.com/v/14423 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14977.jpg Target Cell Response to Hormones Hormones intricately bind to receptors on the surface or within target cells, initiating a cascade of cellular responses. Notably, the cellular response can be regulated by altering the number of receptors expressed in the cell. For example, prolonged exposure to elevated hormone levels results in a gradual decline or down-regulation in the number of receptors for that specific hormone on the cell surface. Conversely, in response to low hormone levels, cells may use up-regulation, producing an... https://www.jove.com/v/14977 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14986.jpg Anatomy of the Adrenal Glands The adrenal or supra-renal glands, situated above the kidneys and aligned with the twelfth rib, are paired pyramid-shaped structures crucial for the body's stress response. During stress, these glands secrete hormones vital for adaptive physiological reactions. These glands possess a distinctive yellow tinge due to the stored cholesterol and fatty acids required for hormone synthesis. They are encased in a fibrous capsule and cushioned by fat. The adrenal gland comprises two distinct regions... https://www.jove.com/v/14986 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14987.jpg Hormones of the Adrenal Glands Adrenal hormones play a pivotal role in maintaining the body's electrolyte balance and orchestrating responses to stress, showcasing the intricate functions of the adrenal cortex and medulla. The adrenal cortex, a powerhouse of hormone synthesis, generates over two dozen corticosteroid hormones. The zona glomerulosa produces mineralocorticoids, exemplified by aldosterone, influencing the electrolyte composition of body fluids. The synthesis of glucocorticoids such as cortisol and corticosterone... https://www.jove.com/v/14987 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14988.jpg Adrenal Gland Disorders Adrenal gland disorders manifest when the production of adrenal hormones deviates from the norm, resulting in either excessive or insufficient concentrations. Adrenal insufficiency, characterized by insufficient cortisol and aldosterone production, leads to conditions like Addison's disease. This disorder, affecting the adrenal cortex, exhibits symptoms such as skin bronzing, dehydration, low blood pressure, fatigue, and weight loss. Congenital adrenal hyperplasia, a genetic ailment causing... https://www.jove.com/v/14988 87 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55019.jpg SorLA and CLC:CLF-1-dependent Downregulation of CNTFRα as Demonstrated by Western Blotting, Inhibition of Lysosomal Enzymes, and Immunocytochemistry The present protocol describes how Western blotting and immunocytochemistry combined with inhibition of lysosomal enzymes can be used to demonstrate the downregulation of Ciliary Neurotrophic Factor Receptor-α (CNTFRα), which is conveyed by the interaction between Cytokine-like Factor-1 (CLF-1) and the endocytic receptor sorLA. https://www.jove.com/v/55019 616 2017-01-06T18:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58530.jpg Isolation, Fixation, and Immunofluorescence Imaging of Mouse Adrenal Glands Here we present a method to isolate adrenal glands from mice, fix the tissues, section them, and perform immunofluorescence staining. https://www.jove.com/v/58530 517 2018-10-02T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59016.jpg Primary Culture of Rat Adrenocortical Cells and Assays of Steroidogenic Functions The hormone secreted by the adrenal cortex is vital for animals against stress and diseases. Here, we present a protocol to culture the primary rat adrenal cells. It could be a good in vitro platform for investigating the mechanisms of the reagent of interest in adrenal steroidogenesis and lipid biosynthesis. https://www.jove.com/v/59016 273 2019-03-12T19:30:00+00:00 JoVE no https://visualize.jove.com/10861289-mammalian-artificial-chromosome-formation-from-circular-alphoid-input-dna-does-not-require-telomere-repeats monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10789.jpg Replication in Eukaryotes Overview In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus. Many Proteins Orchestrate Replication at the Origin Eukaryotic replication follows many of the... https://www.jove.com/v/10789 151 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11529.jpg Chromosome Structure A functional eukaryotic chromosome must contain three elements: a centromere, telomeres, and numerous origins of replication. The centromere is a DNA sequence that links sister chromatids. This is also where kinetochores, protein complexes to which spindle microtubules attach, are constructed after the chromosome is replicated. The kinetochores allow the spindle microtubules to move the chromosomes within the cell during cell division. Telomeres consist of non-coding repetitive nucleotide... https://www.jove.com/v/11529 160 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11539.jpg Lampbrush Chromosomes In 1882, Flemming observed lampbrush chromosomes (LBC) in salamander eggs. Later in 1892, Rückert observed LBCs in shark egg cells and coined the term "lampbrush chromosomes" because they looked like brushes used to clean kerosene lamps. LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops resemble the... https://www.jove.com/v/11539 111 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11540.jpg Polytene Chromosomes Polytene chromosomes are giant interphase chromosomes with several DNA strands placed side by side. They were discovered in the year 1881 by Balbiani in salivary glands, intestine, muscles, malpighian tubules, and hypoderm of larvae Chironomus plumosus. Hence, these are also called "Salivary gland chromosomes." These are found in insects of the order Diptera and Collembola; in certain organs of mammals; and synergids, antipodes of flowering plants. Polytene chromosomes are also regularly... https://www.jove.com/v/11540 124 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11555.jpg Telomeres and Telomerase In eukaryotic DNA replication, a single-stranded DNA fragment remains at the end of a chromosome after the removal of the final primer. This section of DNA cannot be replicated in the same manner as the rest of the strand because there is no 3’ end to which the newly synthesized DNA can attach. This non-replicated fragment results in gradual loss of the chromosomal DNA during each cell duplication. Additionally, it can induce a DNA damage response by enzymes that recognize single-stranded DNA. https://www.jove.com/v/11555 161 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13196.jpg Replication in Eukaryotes In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fulfill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus. Many Proteins Orchestrate Replication at the Origin Eukaryotic replication follows many of the same... https://www.jove.com/v/13196 89 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54239.jpg Genome-wide Purification of Extrachromosomal Circular DNA from Eukaryotic Cells This paper presents a sensitive method called Circle-Seq for purifying extrachromosomal circular DNA (eccDNA). The method encompasses column purification, removal of remaining linear chromosomal DNA, rolling-circle amplification and high-throughput sequencing. Circle-Seq is applicable to genome-scale screening of eukaryotic eccDNA and studying genome instability and copy-number variation. https://www.jove.com/v/54239 866 2016-04-04T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58790.jpg Generation of Cancer Cell Clones to Visualize Telomeric Repeat-containing RNA TERRA Expressed from a Single Telomere in Living Cells Here, we present a protocol to generate cancer cell clones containing a MS2 sequence tag at a single subtelomere. This approach, relying on the MS2-GFP system, enables visualization of the endogenous transcripts of telomeric repeat-containing RNA (TERRA) expressed from a single telomere in living cells. https://www.jove.com/v/58790 553 2019-01-17T22:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59760.jpg Use of Alu Element Containing Minigenes to Analyze Circular RNAs We clone and analyze reporter genes generating circular RNAs. These reporter genes are larger than constructs to analyze linear splicing and contain Alu elements. To investigate the circular RNAs, the constructs are transfected into cells and resulting RNA is analyzed using RT-PCR after removal of linear RNA. https://www.jove.com/v/59760 790 2020-03-10T19:00:00+00:00 JoVE no https://visualize.jove.com/10871640-electrogenic-sodium-sodium-exchange-carried-out-by-nak-atpase-containing-the-amino-acid-substitution-glu779ala monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/10706/10706_article_thumb_10706.jpg Primary Active Transport In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps that are embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction they... https://www.jove.com/v/10706 107 2026-06-01T13:28:21+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/10707/10707_article_thumb_10707.jpg Secondary Active Transport One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme “pump” embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of... https://www.jove.com/v/10707 115 2026-06-01T13:27:48+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11876.jpg Primary Active Transport In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction they would not... https://www.jove.com/v/11876 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11880.jpg Secondary Active Transport One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme "pump" embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of... https://www.jove.com/v/11880 92 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11880.jpg Secondary Active Transport One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme "pump" embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of... https://www.jove.com/v/13941 92 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16497.jpg Active Transport Active transport is a critical biological process that allows cells to move solutes against an electrochemical gradient. This process requires direct energy input and is characterized by its selectivity, saturability, and susceptibility to competitive inhibition. Primary active transporters, like Na+, K+ and -ATPase, directly utilize ATP to move ions across the membrane. These transporters play significant roles in various physiological processes. For instance, Na+, K+ and -ATPase maintain... https://www.jove.com/v/16497 74 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50201.jpg Measuring Cation Transport by Na,K- and H,K-ATPase in Xenopus Oocytes by Atomic Absorption Spectrophotometry: An Alternative to Radioisotope Assays We describe a method to quantify the activity of K+-countertransporting P-type ATPases by heterologous expression of the enzymes in Xenopus oocytes and measuring Rb+ or Li+ uptake into individual cells by atomic absorption spectrophotometry. The method is a sensitive and safe alternative to radioisotope flux experiments facilitating complex kinetic studies. https://www.jove.com/v/50201 768 2013-02-19T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52453.jpg Functional Characterization of Na + /H + Exchangers of Intracellular Compartments Using Proton-killing Selection to Express Them at the Plasma Membrane The first part of this article shows how to select mutant cell lines expressing vesicular Na+/H+ exchangers at their plasma membrane. The second part provides protocols based on intracellular pH measurements and fast ion uptake, which are used to determine the ion selectivity and the kinetic parameters of these exchangers. https://www.jove.com/v/52453 458 2015-03-30T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56630.jpg Application of Electrophysiology Measurement to Study the Activity of Electro-Neutral Transporters This manuscript describes the applications of proton-selective electrodes and patch clamping methods to measure the activity of proton transport systems. These methods overcome some limitations of techniques commonly used to study proton transport activity, such as moderate sensitivity, time resolution and insufficient intracellular milieu control. https://www.jove.com/v/56630 711 2018-02-03T22:00:00+00:00 JoVE no https://visualize.jove.com/10897345-an-introduction-to-analysis-of-variance-anova-with-special-reference-to-data-from-clinical-experiments-in-optometry monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13619.jpg What is an ANOVA? The Analysis of Variance or ANOVA is a statistical test developed by Ronald Fisher in 1918. It is performed on three or more samples to check for equality between their means. Before performing ANOVA, one must ensure that the samples used for this analysis have three crucial characteristics or statistical assumptions. The first assumption states that the samples should be drawn from normally distributed samples, while the second requires that all the drawn samples should be randomly and... https://www.jove.com/v/13619 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13620.jpg One-Way ANOVA One-way ANOVA analyzes more than three samples categorized by one factor. For example, it can compare the average mileage of sports bikes. Here, the data is categorized by one factor - the company. However, one-way ANOVA cannot be used to simultaneously compare the sample mean of three or more samples categorized by two factors. An example of two factors would be sports bikes from different companies driven in different terrains, such as a desert or snowy landscape. Here, two-way ANOVA is used... https://www.jove.com/v/13620 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13622.jpg One-Way ANOVA: Unequal Sample Sizes One-way ANOVA can be performed on three or more samples of unequal sizes. However, calculations get complicated when sample sizes are not always the same. So, while performing ANOVA with unequal samples size, the following equation is used: In the equation, n is the sample size, ͞x is the sample mean, x̿ is the combined mean for all the observations, k is the number of samples, and s2 is the variance of the sample. It should be noted that the subscript 'i' represents a specific sample in a... https://www.jove.com/v/13622 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13624.jpg Two-Way ANOVA The two-way ANOVA is an extension of the one-way ANOVA. It is a statistical test performed on three or more samples categorized by two factors - a row factor and a column factor. Ronald Fischer mentioned it in 1925 in his book 'Statistical Methods for Researchers.' The two-way ANOVA analysis initially begins by stating the null hypothesis that there is an interaction effect between the two factors of a dataset. This effect can be visualized using line segments formed by joining the means for... https://www.jove.com/v/13624 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16481.jpg Statistical Methods to Analyze Parametric Data: ANOVA Analysis of Variance, or ANOVA, is a powerful statistical technique used to analyze parametric data, primarily in research and experimental studies. It's designed to compare the means of two or more groups, assisting researchers in identifying any significant differences between these group means. There are two main types of ANOVA based on the complexity of the analysis: one-way and two-way. One-way ANOVA is applied when a single independent variable or factor is scrutinized. It compares the... https://www.jove.com/v/16481 72 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17358.jpg What is ANOVA? The Analysis of Variance or ANOVA is a statistical test developed by Ronald Fisher in 1918. It is performed on three or more samples to check for equality between their means. Before performing ANOVA, one must ensure that the samples used for this analysis have three crucial characteristics or statistical assumptions. The first assumption states that the samples should be drawn from normally distributed samples, while the second requires that all the drawn samples be randomly and independently... https://www.jove.com/v/17358 73 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60673.jpg Assessing Early Stage Open-Angle Glaucoma in Patients by Isolated-Check Visual Evoked Potential The isolated-check visual evoked potential (icVEP) method is implemented here to assess the magnocellular ON pathway that is initially damaged in glaucoma. The study shows standard operative procedures using icVEP to obtain reliable results. It is proved to serve as a useful objective diagnosing technology for the early detection of glaucoma. https://www.jove.com/v/60673 431 2020-05-25T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63864.jpg Binocular Dynamic Visual Acuity in Eyeglass-Corrected Myopic Patients The present research demonstrates a method to accurately examine dynamic visual acuity (DVA) in myopic subjects with eyeglass correction. Further analysis indicated that the closer the refraction state to emmetropia, the better the eyeglass-corrected binocular DVA is at both 40 and 80 degrees per second. https://www.jove.com/v/63864 426 2022-03-29T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68422.jpg Comparison of Agreement and Accuracy using Binocular Wavefront Optometer with Autorefractor and Phoropter The binocular wavefront optometer agrees well with traditional refraction techniques in both objective and subjective refraction measurements, offering superior accuracy and clinical utility. Its standardized protocol reduces optometrist workload and provides a more accurate refractive assessment for post-refractive surgery individuals. https://www.jove.com/v/68422 314 2025-09-16T19:30:00+00:00 JoVE no https://visualize.jove.com/10916267-receiver-operating-characteristic-analysis-for-intelligent-medical-systems-a-new-approach-for-finding-confidence-intervals monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13586.jpg Confidence Intervals An unbiased point estimate is often insufficient to predict a population estimate, such as population mean or population proportion. In this scenario, a confidence interval is used. A confidence interval is an estimate similar to a sample proportion. However, unlike the point estimate which is a single value, the confidence interval contains a range of values. These values have lower and upper limits, known as confidence limits, and can be designated as L1 and L2, respectively. A confidence... https://www.jove.com/v/13586 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13587.jpg Interpretation of Confidence Intervals A confidence interval is a better estimate of the population than a point estimate, as it uses a range of values from a sample instead of a single value. Confidence intervals have confidence coefficients that are crucial for their interpretation. The most common confidence coefficients are 0.90, 0.95, and 0.99, which can be written as percentages–90%, 95%, and 99%, respectively. Suppose a person calculates a confidence interval with a confidence coefficient of 0.95. In that case, they can... https://www.jove.com/v/13587 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14513.jpg Uncertainty: Confidence Intervals The confidence interval is the range of values around the mean that contains the true mean. It is expressed as a probability percentage. The interpretation of a 95% confidence interval, for instance, is that the statistician is 95% confident that the true mean falls within the interval. The upper and lower limits of this range are known as confidence limits. The confidence limits for the true mean are estimated from the sample's mean, the standard deviation, and the statistical factor 't,' or... https://www.jove.com/v/14513 54 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17599.jpg Receiver Operating Characteristic Plot A ROC (Receiver Operating Characteristic) plot is a graphical tool used to assess the performance of a binary classification model by illustrating the trade-off between sensitivity (true positive rate) and specificity (false positive rate). By plotting sensitivity against 1 - specificity across various threshold settings, the ROC curve shows how well the model distinguishes between classes, with a curve closer to the top-left corner indicating a more accurate model. The area under the ROC curve... https://www.jove.com/v/17599 75 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56525.jpg Effective Analysis of Human Exposure Conditions with Body-worn Dosimeters in the 2.4 GHz Band This study describes a protocol to measure exposure levels in the 2.4 GHz band, avoiding the uncertainties caused by the use of personal exposimeters as measuring devices. These alterations of the exposure levels should be taken into account, especially in compliance testing, where exposure limits are defined from non-perturbed data. https://www.jove.com/v/56525 403 2018-05-02T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59100.jpg Application of Biochip Microfluidic Technology to Detect Serum Allergen-specific Immunoglobulin E (sIgE) This paper presents a protocol for detecting serum-specific immunoglobulin E with a microfluidic cartridge-based chemiluminescence system and the evaluation of its usefulness in allergy diagnoses. https://www.jove.com/v/59100 430 2019-04-21T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62101.jpg Implantation of Combined Telemetric ECG and Blood Pressure Transmitters to Determine Spontaneous Baroreflex Sensitivity in Conscious Mice The baroreflex is a heart-rate regulation mechanism by the autonomic nervous system in response to blood-pressure changes. We describe a surgical technique to implant telemetry transmitters for continuous and simultaneous measurement of electrocardiogram and blood pressure in mice. This can determine spontaneous baroreflex sensitivity, an important prognostic marker for cardiovascular disease. https://www.jove.com/v/62101 596 2021-02-14T22:00:00+00:00 JoVE no https://visualize.jove.com/10923025-the-pyc-plasmids-a-series-of-cassette-based-yeast-plasmid-vectors-providing-means-of-counter-selection monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10807.jpg Antibiotic Selection Overview Researchers use antibiotic resistance genes to identify bacteria that possess a plasmid containing their gene of interest. Antibiotic resistance naturally occurs when a spontaneous DNA mutation creates changes in bacterial genes that eliminate antibiotic activity. Bacteria can share these new resistance genes with their offspring and other bacteria. The overuse and misuse of antibiotics have created a public health crisis, as resistant and multi-resistant bacteria continue to develop.<br... https://www.jove.com/v/10807 57 JoVE no https://cloudfront.jove.com/files/ftp_upload/19546/19546_article_thumb_19546.jpg Plasmids Plasmids are extrachromosomal DNA molecules found in bacteria, archaea, and some eukaryotic microbes like yeast. These small, circular DNA structures typically contain fewer than 30 genes, although some may exist linearly. Plasmids vary in their number within a cell, known as copy number. Single-copy plasmids are present in one copy per cell and multi-copy plasmids are present in multiple copies, reaching over 100 copies per cell.Plasmids usually replicate independently of the chromosomal DNA... https://www.jove.com/v/19546 88 2025-06-12T16:17:16+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57499.jpg Gene-targeted Random Mutagenesis to Select Heterochromatin-destabilizing Proteasome Mutants in Fission Yeast This article describes a detailed methodology for random mutagenesis of a target gene in fission yeast. As an example, we target rpt4+, which encodes a subunit of the 19S proteasome, and screen for mutations that destabilize heterochromatin. https://www.jove.com/v/57499 438 2018-05-15T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61993.jpg Rapid Assembly of Multi-Gene Constructs using Modular Golden Gate Cloning The goal of this protocol is to provide a detailed, step-by-step guide for assembling multi-gene constructs using the modular cloning system based on Golden Gate cloning. It also gives recommendations on critical steps to ensure optimal assembly based on our experiences. https://www.jove.com/v/61993 511 2021-02-05T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66994.jpg Protein Engineering by Yeast Surface Display This protocol describes the essential steps for conducting yeast surface display selection campaigns to enrich protein variants binding to an antigen of interest. https://www.jove.com/v/66994 349 2024-11-29T21:40:00+00:00 JoVE no https://visualize.jove.com/10927155-nuclear-labeling-index-analysis-nlia-a-software-package-used-to-perform-accurate-automation-of-cell-nuclear-labeling-index-analysis-on-immunohistochemically-stained-rat-liver-samples monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13393.jpg Immunocytochemistry and Immunohistochemistry Immunocytochemistry (ICC) and immunohistochemistry (IHC) are techniques that use antibodies to check for specific proteins or antigens in a sample. The technique was first published by Albert Coons in 1941 to detect the presence of pneumococcal antigen in tissue sections from mice infected with Pneumococcus. Immunocytochemistry helps localization of proteins or antigens in individual cells like blood cells, stem cells, etc., while immunohistochemistry does the same for tissue samples. These... https://www.jove.com/v/13393 82 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50425.jpg Immunohistochemical Analysis in the Rat Central Nervous System and Peripheral Lymph Node Tissue Sections We here present an optimized, detailed protocol for double immunostaining in formalin-fixed, paraffin-embedded rat central nervous system (CNS) and peripheral lymph node (LN) tissue sections. https://www.jove.com/v/50425 551 2016-11-14T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60095.jpg A High-Throughput In Situ Method for Estimation of Hepatocyte Nuclear Ploidy in Mice We present a robust, cost-effective, and flexible method for measuring changes in hepatocyte number and nuclear ploidy within fixed/cryopreserved tissue samples that does not require flow cytometry. Our approach provides a powerful sample-wide signature of liver cytology ideal for tracking the progression of liver injury and disease. https://www.jove.com/v/60095 524 2020-04-19T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61295.jpg An Automated Differential Nuclear Staining Assay for Accurate Determination of Mitocan Cytotoxicity The protocol describes a rapid, high-throughput, reliable, inexpensive, and unbiased assay for efficiently determining cellular viability. This assay is particularly useful when cells' mitochondria have been damaged, which interferes with other assays. The assay uses automated counting of cells stained with two nuclear dyes – Hoechst 33342 and propidium iodide. https://www.jove.com/v/61295 478 2020-05-12T22:00:00+00:00 JoVE no https://visualize.jove.com/10935919-multispikes-and-synchronization-in-a-large-neural-network-with-temporal-delays monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10846.jpg Long-term Potentiation Long-term potentiation, or LTP, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTP is the process of synaptic strengthening that occurs over time between pre- and postsynaptic neuronal connections. The synaptic strengthening of LTP works in opposition to the synaptic weakening of long-term depression (LTD) and together are the main mechanisms that underlie learning and memory. Hebbian LTP LTP can occur when presynaptic... https://www.jove.com/v/10846 95 2025-10-23T18:49:27+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/14894/14894_article_thumb_14894.jpg Propagation of Action Potentials The propagation of an action potential refers to the process by which a nerve impulse, or "action potential," travels along a neuron. Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to... https://www.jove.com/v/14894 83 2025-08-11T22:39:58+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14899.jpg Integration of Synaptic Events Synaptic integration mainly includes the summation of graded potentials. Graded potentials, regardless of their type, cause subtle alterations in membrane voltage, resulting in either depolarization or hyperpolarization. These incremental changes, when combined or summed, can propel the neuron toward its threshold. Consider, for example, a membrane experiencing a +15 mV shift, causing it to depolarize from -70 mV to -55 mV. In this scenario, graded potentials govern the membrane's ability to... https://www.jove.com/v/14899 88 2025-06-13T16:06:36+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14900.jpg Neural Circuits Neural circuits and neuronal pools are two of the main structures found in the nervous system. Neural circuits are networks of neurons that work together to carry out a specific task or process. They consist of interconnected neurons and glial cells, which provide structural and metabolic support. Neuronal pools are collections of nerve cells with similar functions and interact through chemical and electrical signals. These pools include both interneurons (the central neural circuit nodes that... https://www.jove.com/v/14900 85 2025-06-13T16:07:11+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52320.jpg Real-time Electrophysiology: Using Closed-loop Protocols to Probe Neuronal Dynamics and Beyond Closed-loop protocols are becoming increasingly widespread in modern day electrophysiology. We present a simple, versatile and inexpensive way to perform complex electrophysiological protocols in cortical pyramidal neurons in vitro, using a desktop computer and a digital acquisition board. https://www.jove.com/v/52320 488 2015-06-24T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52341.jpg Closed-loop Neuro-robotic Experiments to Test Computational Properties of Neuronal Networks In this paper, an experimental framework to perform closed-loop experiments is presented, in which information processing (i.e., coding and decoding) and learning of neuronal assemblies are studied during the continuous interaction with a robotic body. https://www.jove.com/v/52341 678 2015-03-02T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59812.jpg Using Neuron Spiking Activity to Trigger Closed-Loop Stimuli in Neurophysiological Experiments This protocol demonstrates how to use an electrophysiological system for closed-loop stimulation triggered by neuronal activity patterns. Sample Matlab code that can be easily modified for different stimulation devices is also provided. https://www.jove.com/v/59812 319 2019-11-12T19:00:00+00:00 JoVE no https://visualize.jove.com/10941892-the-management-of-one-level-anterior-cervical-corpectomy-with-fusion-using-atlantis-hybrid-plates-preliminary-experience monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/57830.jpg Cone Beam Intraoperative Computed Tomography-based Image Guidance for Minimally Invasive Transforaminal Interbody Fusion The purpose of this article is to provide image-guidance for minimally invasive transforaminal interbody fusion. https://www.jove.com/v/57830 337 2019-08-06T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66878.jpg Surgical Approach and Complications of Stand-alone Lateral Trans-Psoas Interbody Fusion Interbody fusion of the lumbar spine can be achieved surgically using different techniques. Minimally invasive techniques, including lateral interbody fusion, have been developed within recent decades to reduce rates of complications and allow for quicker patient recovery. We provide insight into stand-alone lateral trans-psoas interbody fusion, highlighting potential complications and pitfalls. https://www.jove.com/v/66878 330 2025-02-14T20:40:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67543.jpg Multilevel Oblique Lumbar Interbody Fusion in Degenerative Lumbar Disc Disease with Instability This protocol presents the operative technique of multilevel Oblique Lumbar Interbody Fusion (OLIF) in a step-by-step manner, elaborating on the critical steps for achieving optimal outcomes. https://www.jove.com/v/67543 690 2025-07-25T20:50:00+00:00 JoVE no https://visualize.jove.com/10942895-individual-escherichia-coli-cells-studied-from-light-scattering-with-the-scanning-flow-cytometer monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13379.jpg Flow Cytometry The development of flow cytometry techniques began in 1934 with initial attempts by Andrew Moldavan, a bacteriologist who counted the cells in a flowing capillary system. Moldavan pumped cells through a capillary tube focused under a microscope for visualization. The invention of photometry allowed the measurement of differentially-stained cells, and Louis Kamentsky developed the first multiparameter flow cytometer in 1965 to identify and count the cancer cells in cervical tissue specimens. In... https://www.jove.com/v/13379 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61048.jpg Quantifying Human Norovirus Virus-like Particles Binding to Commensal Bacteria Using Flow Cytometry The goal of this protocol is to quantify binding of the eukaryotic pathogen human norovirus to bacteria. After performing an initial virus-bacterium attachment assay, flow cytometry is used to detect virally-bound bacteria within the population. https://www.jove.com/v/61048 422 2020-04-29T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61290.jpg Continuous Measurement of Biological Noise in Escherichia Coli Using Time-lapse Microscopy This work presents a microscopy method that allows live imaging of a single cell of Escherichia coli for analysis and quantification of the stochastic behavior of synthetic gene circuits. https://www.jove.com/v/61290 505 2021-04-27T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65788.jpg Imaging Flow Cytometry to Study Microbial Autoaggregation This protocol describes a quantitative approach to measure microbial autoaggregation using imaging flow cytometry. https://www.jove.com/v/65788 319 2023-09-29T21:00:00+00:00 JoVE no https://visualize.jove.com/10953237-neural-systems-as-nonlinear-filters monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3685.jpg A Fully Automated and Highly Versatile System for Testing Multi-cognitive Functions and Recording Neuronal Activities in Rodents In this report, we present a fully automated and highly versatile system capable of simultaneously testing multi-cognitive behaviors and recording neuronal activities for rodents. https://www.jove.com/v/3685 553 2012-05-03T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14900.jpg Neural Circuits Neural circuits and neuronal pools are two of the main structures found in the nervous system. Neural circuits are networks of neurons that work together to carry out a specific task or process. They consist of interconnected neurons and glial cells, which provide structural and metabolic support. Neuronal pools are collections of nerve cells with similar functions and interact through chemical and electrical signals. These pools include both interneurons (the central neural circuit nodes that... https://www.jove.com/v/14900 85 2025-06-13T16:07:11+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16045.jpg Classification of Systems-I Linearity is a system property characterized by a direct input-output relationship, combining homogeneity and additivity. Homogeneity dictates that if an input x(t) is multiplied by a constant c, the output y(t) is multiplied by the same constant. Mathematically, this is expressed as: Additivity means that the response to the sum of multiple inputs is the sum of their individual responses. For inputs x1(t) and x2(t) producing outputs y1(t) and y2(t), respectively: Combining homogeneity and... https://www.jove.com/v/16045 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16047.jpg Linear time-invariant Systems A system is linear if it displays the characteristics of homogeneity and additivity, together termed the superposition property. This principle is fundamental in all linear systems. Linear time-invariant (LTI) systems include systems with linear elements and constant parameters. The input-output behavior of an LTI system can be fully defined by its response to an impulsive excitation at its input. Once this impulse response is known, the system's reaction to any other input can be calculated... https://www.jove.com/v/16047 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16094.jpg Feedback control systems Feedback control systems are categorized in various ways based on their design, analysis, and signal types. Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity... https://www.jove.com/v/16094 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16099.jpg Linear Approximation in Frequency Domain Linear systems are characterized by two main properties: superposition and homogeneity. Superposition allows the response to multiple inputs to be the sum of the responses to each individual input. Homogeneity ensures that scaling an input by a scalar results in the response being scaled by the same scalar. In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear. https://www.jove.com/v/16099 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16112.jpg First Order Systems First-order systems, such as RC circuits, are foundational in understanding dynamic systems due to their straightforward input-output relationship. Analyzing their responses to different input functions under zero initial conditions reveals significant insights into system behavior. When a first-order system is subjected to a unit-step input, its response is characterized by its transfer function. By applying the Laplace transform of the unit-step input to the transfer function, expanding the... https://www.jove.com/v/16112 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52320.jpg Real-time Electrophysiology: Using Closed-loop Protocols to Probe Neuronal Dynamics and Beyond Closed-loop protocols are becoming increasingly widespread in modern day electrophysiology. We present a simple, versatile and inexpensive way to perform complex electrophysiological protocols in cortical pyramidal neurons in vitro, using a desktop computer and a digital acquisition board. https://www.jove.com/v/52320 488 2015-06-24T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52341.jpg Closed-loop Neuro-robotic Experiments to Test Computational Properties of Neuronal Networks In this paper, an experimental framework to perform closed-loop experiments is presented, in which information processing (i.e., coding and decoding) and learning of neuronal assemblies are studied during the continuous interaction with a robotic body. https://www.jove.com/v/52341 678 2015-03-02T22:00:00+00:00 JoVE no https://visualize.jove.com/10971753-the-lactoperoxidase-system-the-influence-of-iodide-and-the-chemical-and-antimicrobial-stability-over-the-period-of-about-18-months monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11763.jpg Autoxidation of Ethers to Peroxides and Hydroperoxides Ethers represent a class of chemical compounds that become more dangerous with prolonged storage because they tend to form explosive peroxides when standing in the air. Autoxidation is the spontaneous oxidation of a compound in air. In the presence of oxygen, ethers slowly oxidize to form hydroperoxides and dialkyl peroxides. If concentrated or heated, these peroxides may explode. Hence, ethers should be obtained in small quantities, kept in tightly sealed containers, and used promptly to... https://www.jove.com/v/11763 143 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14555.jpg Redox Titration: Iodimetry and Iodometry Iodometry and iodimetry are analytical methods used to determine the concentration of oxidizing or reducing agents using iodine. In iodometric titrations, the oxidizing analyte solution is usually acidified and treated with an excess of iodide ions, which generates an equivalent amount of iodine in equilibrium with triiodide. The released iodine is subsequently titrated directly against a standardized reducing agent. As the dilute iodine color becomes pale yellow, a few drops of freshly... https://www.jove.com/v/14555 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16510.jpg Factors Affecting Dissolution: Drug Permeability, Stability and Stereochemistry Orally administered drugs primarily enter the systemic circulation via passive diffusion through the intestinal membranes. The drug's absorption is influenced by drug stability in the gastrointestinal GI tract, membrane permeability, the surface area available for absorption, luminal drug concentration, and residence time in the lumen. Drug permeability can be enhanced by adjusting the lipophilicity, polarity, or molecular size of the drug, promoting its passive transport across intestinal... https://www.jove.com/v/16510 80 JoVE no https://cloudfront.jove.com/files/ftp_upload/17167/17167_article_thumb_17167.jpg Drug Product Stability The long-term stability of drug products is critical to ensuring their quality, safety, and effectiveness over time. Stability directly influences a product's ability to maintain its intended characteristics, ensuring it performs as expected during its intended shelf life. Key attributes such as drug potency, impurities, dissolution, and other physicochemical measures of performance are tested to assess stability. These parameters indicate how well the product retains its quality over time and... https://www.jove.com/v/17167 76 2025-10-03T14:00:32+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40765/40765_article_thumb_40765.jpg Methods of Controlling Food Spoilage Food spoilage is caused by microbial growth or by chemical and physical changes, all of which affect the taste, texture, and safety of food.Temperature-Based PreservationRefrigeration at 0–4 °C slows microbial growth and enzyme activity, making it ideal for short-term storage. However, certain spoilage organisms—such as psychrotrophs like Listeria monocytogenes—can still proliferate at these temperatures. Freezing below -18 °C further slows biological processes by forming ice crystals, which... https://www.jove.com/v/40765 86 2026-05-20T18:17:23+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55400.jpg Controlled-release of Chlorine Dioxide in a Perforated Packaging System to Extend the Storage Life and Improve the Safety of Grape Tomatoes Here, we describe a protocol for the application of a novel, slow-release ClO2 product that reduces spoilage and extends the shelf life of fresh fruit. The slow-release ClO2 product was added to standard commercial grape tomato packaging and tested against Escherichia coli and Alternaria alternata. https://www.jove.com/v/55400 427 2017-04-07T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59302.jpg Measuring Enzymatic Stability by Isothermal Titration Calorimetry The thermal stability of enzyme activity is readily measured by isothermal titration calorimetry (ITC). Most protein stability assays currently used measure protein unfolding, but do not provide information about enzymatic activity. ITC enables direct determination of the effect of enzyme modifications on the stability of enzyme activity. https://www.jove.com/v/59302 517 2019-03-26T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64641.jpg A Novel Method to Determine the Longitudinal Antibacterial Activity of Drug-Eluting Materials Here, we present a protocol to evaluate the antibacterial efficacy of an antibiotic-eluting polymer to simulate prophylactic clinical application by using a commercially available real-time ATP-based luminescent microbial viability assay. This method enables the monitoring of the longitudinal activity of drug-eluting materials and can be widely adapted to test anti-microbial drug delivery platforms. https://www.jove.com/v/64641 378 2023-03-03T21:35:00+00:00 JoVE no https://visualize.jove.com/10987194-integrons-an-antibiotic-resistance-gene-capture-and-expression-system monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3698.jpg Site-specific Bacterial Chromosome Engineering: ΦC31 Integrase Mediated Cassette Exchange (IMCE) A quick and efficient method to integrate foreign DNA of interest into pre-made acceptor strains, termed landing pad strains, is described. The method allows site-specific integration of a DNA cassette into the engineered landing pad locus of a given strain, through conjugation and expression of the ΦC31 integrase. https://www.jove.com/v/3698 501 2012-03-16T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10807.jpg Antibiotic Selection Overview Researchers use antibiotic resistance genes to identify bacteria that possess a plasmid containing their gene of interest. Antibiotic resistance naturally occurs when a spontaneous DNA mutation creates changes in bacterial genes that eliminate antibiotic activity. Bacteria can share these new resistance genes with their offspring and other bacteria. The overuse and misuse of antibiotics have created a public health crisis, as resistant and multi-resistant bacteria continue to develop.<br... https://www.jove.com/v/10807 57 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11570.jpg Overview of Transposition and Recombination Transposons make up a significant part of genomes of various organisms. Therefore, it is believed that transposition played a major evolutionary role in speciation by changing genome sizes and modifying gene expression patterns. For example, in bacteria, transposition can lead to conferring antibiotic resistance. Movement of transposable elements within the genetic pool of pathogenic bacteria can aid in transfer of antibiotic-resistant genetic elements. In eukaryotes, transposons can carry out... https://www.jove.com/v/11570 133 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11571.jpg DNA-only Transposons DNA-only transposons are called autonomous transposons since they code for the enzyme transposase that is required for the transposition mechanism. Insertion of transposons can alter gene functions in multiple ways. They can mutate the gene, alter gene expression by introducing a novel promoter or insulator sequence, introduce new splice sites, and change the mRNA transcripts produced, or remodel chromatin structure. The donor site from where the transposon is excised is either degraded or... https://www.jove.com/v/11571 177 JoVE no https://cloudfront.jove.com/files/ftp_upload/19547/19547_article_thumb_19547.jpg Transposons Transposons, or "jumping genes," are small mobile genetic elements (MGEs) that range from 700 to 40,000 base pairs in length. They are found in all organisms and can move within the same chromosome or transfer to different chromosomes. In some cases, transposons can also jump between different host DNA molecules, such as plasmids or viruses, contributing to genetic variability.Barbara McClintock first discovered these mobile genetic elements in the 1940s while studying maize genetics, and she... https://www.jove.com/v/19547 84 2025-06-12T16:17:27+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19550/19550_article_thumb_19550.jpg Conjugation Conjugation is a form of horizontal gene transfer that primarily occurs in bacteria and some archaea, promoting genetic diversity and adaptation. Bacteria can acquire resistance genes through conjugative plasmids, allowing them to survive antibiotic treatments that would otherwise be lethal. This process involves direct contact between cells through specialized structures such as the sex pilus and is mediated by conjugative plasmids, including the F (fertility) factor.Conjugation requires... https://www.jove.com/v/19550 79 2025-06-12T16:18:04+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19552/19552_article_thumb_19552.jpg Transduction Among the three main modes of HGT—transformation, conjugation, and transduction—transduction is unique in that it is mediated by bacteriophages, or bacterial viruses.Transduction occurs in two ways. Generalized transduction occurs during the lytic cycle of a bacteriophage infection. In this process, bacteriophages infect bacterial cells, replicate within them, and ultimately cause cell lysis, releasing newly assembled virions. Occasionally, random fragments of the bacterial genome are... https://www.jove.com/v/19552 76 2025-06-12T16:18:24+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52889.jpg Screening Foodstuffs for Class 1 Integrons and Gene Cassettes This protocol describes the detection of class 1 integrons and their associated gene cassettes in foodstuffs. https://www.jove.com/v/52889 577 2015-06-19T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66471.jpg Characterizing Multidrug Efflux Systems in Acinetobacter baumannii Using an Efflux-Deficient Bacterial Strain and a Single-Copy Gene Expression System We describe a facile procedure for the single-copy chromosomal complementation of an efflux pump gene using a mini-Tn7-based expression system into an engineered efflux-deficient strain of Acinetobacter baumannii. This precise genetic tool allows for controlled gene expression, which is key for the characterization of efflux pumps in multidrug resistant pathogens. https://www.jove.com/v/66471 306 2024-01-05T23:00:00+00:00 JoVE no https://visualize.jove.com/10991141-origin-of-complexity-in-multicellular-organisms monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10909.jpg Gastrulation Gastrulation establishes the three primary tissues of an embryo: the ectoderm, mesoderm, and endoderm. This developmental process relies on a series of intricate cellular movements, which in humans transforms a flat, “bilaminar disc” composed of two cell sheets into a three-tiered structure. In the resulting embryo, the endoderm serves as the bottom layer, and stacked directly above it is the intermediate mesoderm, and then the uppermost ectoderm. Respectively, these tissue strata will form... https://www.jove.com/v/10909 116 2025-10-23T18:49:04+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12437.jpg Eukaryotic Evolution The endosymbiont theory is the most widely accepted theory of eukaryotic evolution; however, its progression is still somewhat debated. According to the nucleus-first hypothesis, the ancestral prokaryote first evolved a membrane to enclose DNA and form the nucleus. Conversely, the mitochondria-first hypothesis suggests that the nucleus was formed after endosymbiosis of mitochondria. Contrary to the endosymbiont theory, the eukaryote-first hypothesis proposes that the simpler prokaryotic and... https://www.jove.com/v/12437 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13461.jpg Zygotic Development And Stem Cell Formation The development of all multicellular organisms starts with the fusion of haploid cells called sperm and egg to form a diploid zygote. A zygote is a totipotent cell that can develop into a complete organism. The zygote undergoes cell division or cleavage to form an 8-cell mass. Until this stage, the cells are spherical, loosely attached, and remain totipotent. Totipotent cells are capable of developing both the embryonic and the extraembryonic tissues. However, as they continue to divide, they... https://www.jove.com/v/13461 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13911.jpg Cell Diversity The concept of a cell started with microscopic observations of dead cork tissue by Robert Hooke in 1665. Hooke coined the term "cell" based on the resemblance of the small subdivisions in the cork to the rooms that monks inhabited, called cells. About ten years later, Antonie van Leeuwenhoek became the first person to observe the living and moving cells under a microscope. In the century that followed, the theory that cells represented the basic unit of life developed. Multicellular organisms... https://www.jove.com/v/13911 73 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13959.jpg Cellular Differentiation How does a complex organism such as a human develop from a single cell? It all starts from a single fertilized egg which gives rise to a vast array of cell types, such as nerve cells, muscle cells, and epithelial cells that characterize the adult? Throughout development and adulthood, cellular differentiation leads cells to assume their final morphology and physiology. Differentiation is the process by which unspecialized cells become specialized to carry out distinct functions. A zygote is a... https://www.jove.com/v/13959 57 JoVE no https://cloudfront.jove.com/files/ftp_upload/40719/40719_article_thumb_40719.jpg Origin of Cellular Life The origin of life on Earth is a complex and enigmatic event rooted in ancient biochemical processes and geological conditions. Experimental evidence supports the hypothesis that life began with the spontaneous formation of organic molecules such as RNA nucleotides, amino acids, and lipids under early Earth conditions. Factors like volcanic activity, intense UV radiation, and a reducing atmosphere without free oxygen likely facilitated these reactions. Hydrothermal vents on the ocean floor are... https://www.jove.com/v/40719 84 2026-03-12T20:57:39+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55113.jpg The Power of Simplicity: Sea Urchin Embryos as in Vivo Developmental Models for Studying Complex Cell-to-cell Signaling Network Interactions This video article details a straightforward in vivo methodology that can be used to systematically and efficiently characterize components of complex signaling pathways and regulatory networks in many invertebrate embryos. https://www.jove.com/v/55113 454 2017-02-16T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59634.jpg Mapping the Emergent Spatial Organization of Mammalian Cells using Micropatterns and Quantitative Imaging The method presented here uses micropatterning together with quantitative imaging to reveal spatial organization within mammalian cultures. The technique is easy to establish in a standard cell biology laboratory and offers a tractable system to study patterning in vitro. https://www.jove.com/v/59634 596 2019-04-30T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60282.jpg Imaging and Analysis of Tissue Orientation and Growth Dynamics in the Developing Drosophila Epithelia During Pupal Stages This protocol is designed for the imaging and analysis of the dynamics of cell orientation and tissue growth in the Drosophila abdominal epithelia as the fruit fly undergoes metamorphosis. The methodology described here can be applied to the study of different developmental stages, tissues, and subcellular structures in Drosophila or other model organisms. https://www.jove.com/v/60282 505 2020-06-02T20:00:00+00:00 JoVE no https://visualize.jove.com/11031560-adaptive-estimation-and-control-method-for-unstable-periodic-dynamics-in-spike-trains monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1677.jpg An Experimental Platform to Study the Closed-loop Performance of Brain-machine Interfaces We use a closed-loop fly-machine interface to investigate general principles in neuronal control. https://www.jove.com/v/1677 651 2011-03-10T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16077.jpg Sampling Continuous Time Signal In signal processing, a continuous-time signal can be sampled using an impulse-train sampling technique, followed by the zero-order hold method. Impulse-train sampling involves the use of a periodic impulse train, which consists of a series of delta functions spaced at regular intervals determined by the sampling period. When a continuous-time signal is multiplied by this impulse train, it generates impulses with amplitudes corresponding to the signal's values at the sampling points. In the... https://www.jove.com/v/16077 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16094.jpg Feedback control systems Feedback control systems are categorized in various ways based on their design, analysis, and signal types. Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity... https://www.jove.com/v/16094 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16103.jpg Linear Approximation in Time Domain Nonlinear systems often require sophisticated approaches for accurate modeling and analysis, with state-space representation being particularly effective. This method is especially useful for systems where variables and parameters vary with time or operating conditions, such as in a simple pendulum or a translational mechanical system with nonlinear springs. For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length, the... https://www.jove.com/v/16103 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16111.jpg Transient and Steady-state Response In control systems, test signals are essential for evaluating performance under various conditions. The ramp function is effective for systems undergoing gradual changes, while the step function is suitable for assessing systems facing sudden disturbances. For systems subjected to shock inputs, the impulse function is the most appropriate test signal. These test signals are integral in designing control systems to exhibit two key performance aspects: transient response and steady-state response. https://www.jove.com/v/16111 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16127.jpg Time-Domain Interpretation of PD Control Proportional-Derivative (PD) control is a widely used control method in various engineering systems to enhance stability and performance. In a system with only proportional control, common issues include high maximum overshoot and oscillation, observed in both the error signal and its rate of change. This behavior can be divided into three distinct phases: initial overshoot, subsequent undershoot, and gradual stabilization. Consider the example of control of motor torque. Initially, a positive... https://www.jove.com/v/16127 67 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16170.jpg Multimachine Stability Multimachine stability analysis is crucial for understanding the dynamics and stability of power systems with multiple synchronous machines. The objective is to solve the swing equations for a network of M machines connected to an N-bus power system. In analyzing the system, the nodal equations represent the relationship between bus voltages, machine voltages, and machine currents. The nodal equation is given by: V is the N-vector of bus voltages, E is the M-vector of machine voltages, I is... https://www.jove.com/v/16170 85 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50941.jpg A Simple Stimulatory Device for Evoking Point-like Tactile Stimuli: A Searchlight for LFP to Spike Transitions To elucidate the complex transition from Local Field Potentials (LFPs) to spikes a suitable stimulator for light mechanical peripheral stimuli was built. As an application, the spiking activities recorded from somatosensory cortex were analyzed by a multi-objective optimization strategy. The results demonstrated that the proposed stimulator was able to deliver tactile stimuli with millisecond and millimeter precisions. https://www.jove.com/v/50941 454 2014-03-25T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59898.jpg A Method for Tracking the Time Evolution of Steady-State Evoked Potentials A protocol to assess the time evolution of the neural entrainment to external repetitive stimuli is presented. Steady-state recordings of the same experimental condition are acquired and averaged in the time-domain. The steady-state dynamics are analyzed by plotting the response amplitude as a function of time. https://www.jove.com/v/59898 723 2019-05-25T22:00:00+00:00 JoVE no https://visualize.jove.com/11032256-three-dimensional-intravascular-ultrasound-assessment-of-abdominal-aortic-aneurysm-necks monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17980/17980_article_thumb_17980.jpg Aneurysm II: Clinical Manifestations and Diagnostic Studies Thoracic, aortic arch and abdominal aneurysms are significant vascular conditions that can present with various clinical manifestations and lead to serious complications. Understanding these manifestations and the appropriate diagnostic studies is essential for effective management and treatment.Thoracic Aortic AneurysmsThoracic aortic aneurysms often remain asymptomatic until they reach a size that impinges on adjacent structures. They typically cause deep, diffuse chest pain that radiates to... https://www.jove.com/v/17980 81 2025-06-19T16:19:14+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17981/17981_article_thumb_17981.jpg Aneurysm III: Interprofessional Care Aneurysm management involves either conservative medical therapy or surgical intervention, depending on the size and symptoms of the aneurysm. Conservative management is generally reserved for smaller, asymptomatic aneurysms, while larger or symptomatic aneurysms often necessitate surgical repair.Conservative Medical TherapyFor small, asymptomatic aneurysms, particularly abdominal aortic aneurysms (AAA) less than 5.5 centimeters in diameter, conservative medical therapy is recommended. This... https://www.jove.com/v/17981 86 2025-06-19T16:19:25+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64124.jpg Drug Treatment by Central Venous Catheter in a Mouse Model of Angiotensin II Induced Abdominal Aortic Aneurysm and Monitoring by 3D Ultrasound This protocol describes the consecutive implantation of an osmotic pump to induce abdominal aortic aneurysm by angiotensin II release in apolipoprotein E (ApoE) deficient mice and of a vascular access port with a jugular vein catheter for repeated drug treatment. Monitoring of aneurysm development by 3D ultrasound is effectively conducted despite dorsal implants. https://www.jove.com/v/64124 609 2022-08-04T20:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65487.jpg An Approach to Point-Of-Care Ultrasound Evaluation of the Abdominal Aorta This protocol reviews the steps to image the abdominal aorta with point-of-care ultrasound. We discuss image acquisition, troubleshooting imaging pitfalls and artifacts, and the recognition of life-threatening abdominal aortic pathology. https://www.jove.com/v/65487 432 2023-09-08T20:40:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67400.jpg Three-Dimensional Imaging of Aortic Tissues in Atherosclerosis Here, we present optimized tissue-clearing protocols to image the murine aorta in three dimensions (3D). We delineate state-of-the-art procedures for immunostaining, optical clearing, and imaging with the intent to define the anatomical proximity of the peripheral nervous system with atherosclerotic plaques and the adventitia in atherosclerosis. https://www.jove.com/v/67400 595 2024-10-25T22:00:00+00:00 JoVE no https://visualize.jove.com/11079953-assessing-the-accuracy-of-an-automated-coding-system-in-emergency-medicine monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13545.jpg Documentation of Nursing Diagnosis The nurse documents nursing diagnoses and enters them into the patient record. The identified patient's nursing diagnosis is either written out with a plan of care or entered into the electronic health record. In some settings, data-driven computerized decision support systems are in place, allowing for more accurate nursing diagnoses. The database within one of these systems includes diagnostic labels defining characteristics, activities, and indicators for nursing. A nurse enters assessment... https://www.jove.com/v/13545 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14113.jpg Methods of Documentation V: CBE Charting by Exception, or CBE, is a method of documentation used in healthcare, particularly in nursing, that focuses on documenting only significant or abnormal findings rather than recording every detail. This approach aims to streamline the documentation process, improve efficiency, and ensure that healthcare providers can quickly identify deviations from normalcy in patient assessments. In CBE, healthcare professionals establish predefined standards of practice that define what constitutes... https://www.jove.com/v/14113 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14115.jpg Methods of Documentation VII: EMR Electronic Medical Records (EMRs) primarily center around electronically documenting patients' health information within a single healthcare organization or practice. They contain essential clinical data related to a patient's medical history, diagnoses, medications, treatment plans, lab results, and other pertinent information relevant to the specific encounter or episode of care. EMRs are designed to streamline documentation and workflow processes within individual healthcare settings,... https://www.jove.com/v/14115 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14507.jpg Systematic Error: Methodological and Sampling Errors In the case of systematic errors, the sources can be identified, and the errors can be subsequently minimized by addressing these sources. According to the source, systematic errors can be divided into sampling, instrumental, methodological, and personal errors. Sampling errors originate from improper sampling methods or the wrong sample population. These errors can be minimized by refining the sampling strategy. Defective instruments or faulty calibrations are the sources of instrumental... https://www.jove.com/v/14507 75 JoVE no https://cloudfront.jove.com/files/ftp_upload/17948/17948_article_thumb_17948.jpg Cardiopulmonary Resuscitation III: AED Use Introduction to AEDAn Automated External Defibrillator (AED) is a portable medical device that analyzes the heart's rhythm and, if necessary, delivers an electrical shock to help the heart re-establish an effective rhythm during sudden cardiac arrest (SCA). SCA occurs when the heart suddenly and unexpectedly stops beating, leading to a loss of blood flow to the brain and other vital organs. In such emergencies, time is of the essence, and using an AED, combined with Cardiopulmonary... https://www.jove.com/v/17948 83 2025-06-19T16:38:36+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59248.jpg Setup and Execution Of the Blindfolded Code Training Exercise The blindfolded code training exercise, which blindfolds the team leader in a code resuscitation simulation, is an advanced teaching technique to improve closed-loop communication, organizational skills, and critical... https://www.jove.com/v/59248 325 2019-03-29T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59825.jpg Inverse Probability of Treatment Weighting (Propensity Score) using the Military Health System Data Repository and National Death Index When randomized controlled trials are not feasible, a comprehensive health care data source like the Military Health System Data Repository provides an attractive alternative for retrospective analyses. Incorporating mortality data from the national death index and balancing differences between groups using propensity weighting helps reduce biases inherent in retrospective designs. https://www.jove.com/v/59825 415 2020-01-08T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63848.jpg A Computer-Based Platform for Aiding Clinicians in Eating Disorder Analysis and Diagnosis Diagnosing eating disorders in healthcare is challenging. Therefore, the present protocol develops an algorithm based on 949 patient responses to a questionnaire, with the diagnosis displayed on an easy-to-use web-based interface. This system facilitates the accurate diagnosis of eating disorders while excluding those believed to have an eating disorder. https://www.jove.com/v/63848 259 2022-05-10T23:00:00+00:00 JoVE no https://visualize.jove.com/11100802-functional-analysis-of-aberrant-behavior-maintained-by-automatic-reinforcement-assessments-of-specific-sensory-reinforcers monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2292.jpg Operant Sensation Seeking in the Mouse In this protocol we describe a method of operant learning using sensory stimuli as a reinforcer in the mouse. It requires no prior training or food restriction, and it allows the study of motivated behavior without the use of a pharmacological or natural reinforcer such as food. https://www.jove.com/v/2292 519 2010-11-10T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17736.jpg Behaviorism The field of behaviorism was pioneered by figures such as Ivan Pavlov, John B. Watson, and B.F. Skinner fundamentally shifted the focus of psychology to the observable and controllable aspects of human and animal behavior. This shift marked a critical evolution in the discipline, emphasizing scientific rigor and experimental methodology. The core premise of behaviorism is its focus on observable behavior rather than internal thoughts or feelings. This approach argues that true scientific... https://www.jove.com/v/17736 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17812.jpg Law of Effect B.F. Skinner, a prominent figure in behavioral psychology, introduced operant conditioning by emphasizing the role of consequences in shaping behavior. This theory builds upon the law of effect proposed by Edward Thorndike, which posits that behaviors followed by satisfying outcomes are likely to be repeated. In contrast, those followed by unsatisfying outcomes are less likely to recur. Edward Thorndike's foundational work involved studying learning in animals, particularly using puzzle boxes... https://www.jove.com/v/17812 66 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17813.jpg Reinforcement Positive and negative reinforcement are key concepts in operant conditioning, a learning process where the consequences of a behavior affect the likelihood of that behavior being repeated. Positive reinforcement occurs when a behavior is followed by the presentation of a rewarding stimulus, increasing the frequency of that behavior. For example: • If a person smiles at you after you greet them and you continue talking, the smile is a positive reinforcement for your greeting. • Teaching a dog... https://www.jove.com/v/17813 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17818.jpg Generalization, Discrimination, and Extinction Generalization, discrimination, and extinction are key concepts in operant conditioning that influence how behaviors are learned and maintained. Generalization occurs when a behavior reinforced in one context is performed in similar situations. For instance, a student who studies diligently for calculus and receives excellent grades might apply the same study habits to psychology and history, expecting similar results. Generalization shows how learning in one setting can influence behavior in... https://www.jove.com/v/17818 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17821.jpg Behavior Modification Behavioral approaches have often been criticized for ignoring mental processes and focusing solely on observable behavior. However, these approaches provide an optimistic perspective for individuals seeking to change their behaviors. Rather than concentrating on intrinsic personality traits, behavioral approaches suggest that even longstanding habits can be modified by changing the reward contingencies that maintain them. A real-world application of operant conditioning principles is applied... https://www.jove.com/v/17821 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18626.jpg Operant Conditioning Intervention Operant conditioning serves as a foundational principle in therapeutic interventions aimed at modifying maladaptive behaviors. Central to this approach is the notion that behaviors, both adaptive and maladaptive, are learned through reinforcement. By analyzing the environmental factors that reinforce problematic behaviors, clinicians can design interventions to weaken these reinforcements and replace maladaptive behaviors with healthier alternatives. In operant conditioning, behaviors that are... https://www.jove.com/v/18626 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57395.jpg Assessing Activity-based Anorexia in Mice Mice individually housed with a running wheel while given limited access to food develop reductions in food consumption and increase activity on the running wheel. This experimental phenomenon is called activity-based anorexia. This paradigm provides an experimental tool for studying the neurobiology and behaviors underlying aspects of anorexia nervosa. https://www.jove.com/v/57395 506 2018-05-14T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66846.jpg Strategies for Assessing Autistic-Like Behaviors in Mice Rodent models are valuable tools for studying core behaviors related to autism spectrum disorder (ASD). In this article, we expound on two behavioral tests for modeling the core features of ASD in mice: self-grooming, which assesses repetitive behavior, and the three-chamber social interaction test, which documents social impairments. https://www.jove.com/v/66846 458 2024-09-20T20:20:00+00:00 JoVE no https://visualize.jove.com/11108469-optimal-amnesic-probabilistic-automata-or-how-to-learn-and-classify-proteins-in-linear-time-and-space monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11502.jpg Protein Families Protein families are groups of homologous proteins; that is, they have similarities in amino acid sequences and three-dimensional structures. Protein families usually occur because of gene duplication, where an additional copy of a gene is inserted into the genome of an organism. Mutations that change the amino acids but still allow the protein to be properly synthesized, will lead to new protein family members. If these new proteins contain similar amino acids in key locations, protein... https://www.jove.com/v/11502 167 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11503.jpg Conservation of Protein Domains Over Different Proteins Protein domains are small structurally independent units that are part of a single amino acid chain. Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms. A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form... https://www.jove.com/v/11503 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11508.jpg Amyloid Fibrils Amyloid fibrils are aggregates of misfolded proteins. Under most circumstances, misfolded proteins are either refolded by chaperone proteins or degraded by the proteasome. However, in the case of a mutation or a disease, these proteins can accumulate to form large clusters and often further assemble to form elongated fibers, called fibrils. Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining, normally used to... https://www.jove.com/v/11508 183 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11525.jpg Protein Networks An organism can have thousands of different proteins, and these proteins must cooperate to ensure the health of an organism. Proteins bind to other proteins and form complexes to carry out their functions. Many proteins interact with multiple other proteins creating a complex network of protein interactions. These interactions can be represented through maps depicting protein-protein interaction networks, represented as nodes and edges. Nodes are circles that are representative of a protein,... https://www.jove.com/v/11525 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11503.jpg Conservation of Protein Domains Protein domains are small structurally independent units that are part of a single amino acid chain. Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms. A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form... https://www.jove.com/v/12490 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13388.jpg Proteomics A proteome is the entire set of proteins that a cell type produces. We can study proteomes using the knowledge of genomes because genes code for mRNAs, and the mRNAs encode proteins. Although mRNA analysis is a step in the right direction, not all mRNAs are translated into proteins. Proteomics is the study of proteomes' function. It involves the large-scale systematic study of the proteome to denote the protein complement expressed by a genome. Scientist Mark Wilkins coined the term proteomics... https://www.jove.com/v/13388 93 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52878.jpg Optimization of Synthetic Proteins: Identification of Interpositional Dependencies Indicating Structurally and/or Functionally Linked Residues Synthetic protein sequences based on consensus motifs typically ignore co-evolving residues, that imply interpositional dependencies (IPDs). IPDs can be essential to activity, and designs that disregard them may result in suboptimal results. This protocol uses StickWRLD to identify IPDs and help inform rational protein design, resulting in more efficient results. https://www.jove.com/v/52878 428 2015-07-14T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66314.jpg Computational Prediction of Amino Acid Preferences of Potentially Multispecific Peptide-Binding Domains Involved in Protein-Protein Interactions We describe a methodology based on sequence diversification to estimate the amino acid preferences of multispecific binding sites in protein-protein interactions (PPIs). In this strategy, thousands of potential peptide ligands are generated and screened in silico, thus overcoming some limitations of available experimental methods. https://www.jove.com/v/66314 410 2024-01-26T22:55:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67833.jpg Identification and Classification of Position-specific GABA A Receptor Subunit Missense Variants for Their Role In Hippocampal Pyramidal Neurons This study introduces a multiscale framework, spanning from DNA to protein function and neural behavior. It presents a novel approach for investigating predicted pathogenic mutations in the GABAA receptor subunit, hypothesizing that epileptogenic mutations and proximal mutations, predicted as pathogenic, may produce similar effects on the CA1 pyramidal neuron model. https://www.jove.com/v/67833 484 2025-06-06T20:15:00+00:00 JoVE no https://visualize.jove.com/11112258-modeling-selective-attention-using-a-neuromorphic-analog-vlsi-device monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4262.jpg Mapping Cortical Dynamics Using Simultaneous MEG/EEG and Anatomically-constrained Minimum-norm Estimates: an Auditory Attention Example We use magneto- and electroencephalography (MEG/EEG), combined with anatomical information captured by magnetic resonance imaging (MRI), to map the dynamics of the cortical network associated with auditory attention. https://www.jove.com/v/4262 525 2012-10-24T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52958.jpg Measurement of Neurophysiological Signals of Ignoring and Attending Processes in Attention Control Attention control comprises enhancement of target signals and attenuation of distractor signals. We describe an approach to measure separately but concurrently, the neurophysiology of attending and ignoring in sustained intermodal attention, utilizing a passive control condition during which neither process is continuously engaged. https://www.jove.com/v/52958 577 2015-07-05T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56219.jpg Touchscreen Sustained Attention Task (SAT) for Rats Sustained attention, or continuously monitoring situations for intermittent and unpredictable events, is a critical aspect of cognition. Here we detail how to test sustained attention in rats using touchscreen operant chambers. We demonstrate comparable performance in male and female rats, making this task useful for studying attention in both sexes. https://www.jove.com/v/56219 571 2017-09-15T22:00:00+00:00 JoVE no https://visualize.jove.com/11114245-structural-rearrangements-and-insertions-of-dispersed-elements-in-pericentromeric-alpha-satellites-occur-preferably-at-kinkable-dna-sites monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11529.jpg Chromosome Structure A functional eukaryotic chromosome must contain three elements: a centromere, telomeres, and numerous origins of replication. The centromere is a DNA sequence that links sister chromatids. This is also where kinetochores, protein complexes to which spindle microtubules attach, are constructed after the chromosome is replicated. The kinetochores allow the spindle microtubules to move the chromosomes within the cell during cell division. Telomeres consist of non-coding repetitive nucleotide... https://www.jove.com/v/11529 160 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11533.jpg Nucleosome Remodeling Nucleosomes are the basic units of chromatin compaction. Each nucleosome consists of the DNA bound tightly around a histone core, which makes the DNA inaccessible to DNA binding proteins such as DNA polymerase and RNA polymerase. Hence, the fundamental problem is to ensure access to DNA when appropriate, despite the compact and protective chromatin structure. Nucleosome remodeling complex Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes... https://www.jove.com/v/11533 174 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11540.jpg Polytene Chromosomes Polytene chromosomes are giant interphase chromosomes with several DNA strands placed side by side. They were discovered in the year 1881 by Balbiani in salivary glands, intestine, muscles, malpighian tubules, and hypoderm of larvae Chironomus plumosus. Hence, these are also called "Salivary gland chromosomes." These are found in insects of the order Diptera and Collembola; in certain organs of mammals; and synergids, antipodes of flowering plants. Polytene chromosomes are also regularly... https://www.jove.com/v/11540 124 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11541.jpg Histone Variants at the Centromere Histone variants are the histone proteins with structural and sequence variations. These variants may be regarded as “mutant” forms that replace their canonical histone counterparts in the nucleosomes. Specific post-translational modifications on the histone variants enable further chromatin complexity and regulate tissue-specific gene expression. The most common histone variants are from histone H2A, H2B, and linker histone H1 families. However, several variants of histone H3 variants are also... https://www.jove.com/v/11541 150 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11569.jpg Gene Conversion Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new... https://www.jove.com/v/11569 128 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11575.jpg Conservative Site-specific Recombination and Phase Variation Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines. The recognition sites for Cre recombinase called LoxP... https://www.jove.com/v/11575 173 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50087.jpg Combined Immunofluorescence and DNA FISH on 3D-preserved Interphase Nuclei to Study Changes in 3D Nuclear Organization Here we describe a protocol for simultaneous detection of histone modifications by immunofluorescence and DNA sequences by DNA FISH followed by 3D microscopy and analyses (3D immuno-DNA FISH). https://www.jove.com/v/50087 835 2013-02-03T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53732.jpg Immunofluorescence Analysis of Endogenous and Exogenous Centromere-kinetochore Proteins Here we report protocols to detect endogenous and exogenous centromere-kinetochore proteins in human cells and quantify these protein levels at centromeres-kinetochores by indirect immunofluorescent staining through the use of fixation (paraformaldehyde, acetone, or methanol fixation). https://www.jove.com/v/53732 335 2016-03-03T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55946.jpg Determination of the Optimal Chromosomal Location(s) for a DNA Element in Escherichia coli Using a Novel Transposon-mediated Approach Here, the power of a transposon-mediated random insertion of a non-coding DNA element was used to resolve its optimal chromosomal position. https://www.jove.com/v/55946 672 2017-09-11T20:00:00+00:00 JoVE no https://visualize.jove.com/11130924-architecture-for-an-artificial-immune-system monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10895.jpg What is the Immune System? Overview The immune system comprises diverse biological structures and processes that protect the body from disease. These processes can be classified into innate and adaptive immunity. To work effectively, the immune system needs to detect pathogens by distinguishing the body’s own structures from foreign elements. If this determination fails, autoimmune diseases occur in which the immune system reacts against the body’s own tissue. The Innate Immune System Acts Fast and Non-specifically <br... https://www.jove.com/v/10895 98 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10896.jpg Cell-mediated Immune Responses Overview The cell-mediated immune system is the host’s primary response against invasive bacteria and viruses that cause intracellular infections. It is also essential for fighting against and destroying cancer cells. Furthermore, the cell-mediated immune system plays a role in the rejection of organ transplants or graft tissue. The Innate Immune System Activates the Adaptive Immune System Phagocytic cells of the innate immune system, such as macrophages or dendritic cells, are the first to... https://www.jove.com/v/10896 100 2025-10-23T18:49:07+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15325.jpg Introduction to Lymphatic and Immune System Immunity is a crucial biological concept about our body's inherent capacity to prevent infections and diseases. A complex network of cells and tissues collectively known as the immune system facilitates this natural defense mechanism. The immune system plays an integral role in maintaining our health and well-being, shielding us from potential health threats. The immune responses can be categorized into two types: innate and adaptive. Innate immunity comprises nonspecific defenses we are born... https://www.jove.com/v/15325 83 2026-02-13T16:25:05+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15333.jpg Introduction to Innate and Adaptive Immunity The human immune system is a complex defense mechanism that protects the body from harmful pathogens and foreign substances. It comprises two crucial components: innate and adaptive immunity. Innate immunity is the body's natural, nonspecific defense system that acts quickly to protect against pathogens. It incorporates physical barriers like skin and mucous membranes and cellular elements such as phagocytes and natural killer cells. This part of our immune system provides an immediate,... https://www.jove.com/v/15333 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15340.jpg Cells of the Adaptive Immune Response The T and B lymphocytes of the adaptive immune system develop from common lymphoid progenitor cells in the bone marrow. These progenitors give rise to precursors that eventually develop into both T and B lymphocytes. As these precursors mature, they gain the ability to detect and respond to foreign antigens in the body, a process known as immunocompetence. Additionally, these precursors acquire self-tolerance, a process that ensures they do not react to self-antigens. This intricate system... https://www.jove.com/v/15340 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15343.jpg Antigen Presenting Cells The immune system is a complex network of cells and molecules that protects the body from foreign invaders. T cells, a type of white blood cell, play a crucial role in this process. They recognize and attack foreign substances, such as pathogens, that enter the body. T cells require the help of antigen-presenting cells (APCs), which process foreign antigens into smaller fragments that can be recognized by T cells. These APCs are highly specialized cells that efficiently internalize antigens... https://www.jove.com/v/15343 82 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53288.jpg An Endothelial Planar Cell Model for Imaging Immunological Synapse Dynamics Adaptive immunity is controlled by dynamic 'immunological synapses' formed between T cells and antigen presenting cells. This protocol describes methods for investigating endothelial cells both as understudied physiologic APCs and as a novel type of 'planar cellular APC model'. https://www.jove.com/v/53288 565 2015-12-24T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61895.jpg Microfluidic Co-Culture Models for Dissecting the Immune Response in in vitro Tumor Microenvironments In the age of immunotherapy and single-cell genomic profiling, cancer biology requires novel in vitro and computational tools for investigating the tumor-immune interface in a proper spatiotemporal context. We describe protocols to exploit tumor-immune microfluidic co-cultures in 2D and 3D settings, compatible with dynamic, multiparametric monitoring of cellular functions. https://www.jove.com/v/61895 466 2021-04-30T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66602.jpg Immunocompetent Alveolus-on-Chip Model for Studying Alveolar Mucosal Immune Responses Lung-on-chip models surpass traditional 2D cultures by mimicking the air-liquid interface and endothelial cell perfusion, simulating blood flow and nutrient exchange crucial for lung physiology studies. This enhances lung research relevance, offering a dynamic, physiologically accurate environment to advance the understanding and treatment of respiratory infections. https://www.jove.com/v/66602 630 2024-05-31T20:20:00+00:00 JoVE no https://visualize.jove.com/11139403-interaction-of-the-alpha-subunit-of-nak-atpase-with-cofilin monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11793.jpg Cytoskeletal Accessory Proteins The cytoskeleton is an essential cell component that plays several structural and functional roles. However, the filaments that make up the cytoskeleton cannot function independently and depend on the accessory or ancillary proteins to effectively carry out their function. Accessory proteins associate with cytoskeletal filaments and their monomers, aiding filament formation and function. They also help in the cross-communication among cytoskeletal filaments. Cytoskeletal accessory proteins are... https://www.jove.com/v/11793 73 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11797.jpg Introduction to Actin Actin is a highly conserved cytoskeletal protein found abundantly in eukaryotic cells. It constitutes 10% weight of the total cellular protein in muscle cells, while in non-muscle cells, it is lower and makes up around 1–5 percent of the total cell protein. Actin found in the unicellular amoebae and complex multicellular animals is around 80% similar, demonstrating their conservation over a billion years of evolution. Actin coding genes are conserved within species and across different species. https://www.jove.com/v/11797 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11800.jpg Actin Filament Depolymerization Actin filaments (F-actin) are composed of actin subunits. The dissociation of actin monomers can occur from either end of F-actin. The rate of dissociation is faster from the minus-end or the pointed end, where the actin subunits exist with a bound ADP, together known as ADP-actin. The depolymerization of F-actin is aided by proteins, including the actin-depolymerizing factor (ADF) and cofilin family of proteins, gelsolin, and glia maturation factor (GMF). In F-actin, the ADF/cofilin proteins... https://www.jove.com/v/11800 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11901.jpg ATP Synthase: Mechanism In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP... https://www.jove.com/v/11901 108 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11904.jpg ATP Synthase: Structure ATP synthase or ATPase is among the most conserved proteins found in bacteria, mammals, and plants. This enzyme can catalyze a forward reaction in response to the electrochemical gradient, producing ATP from ADP and inorganic phosphate. ATP synthase can also work in a reverse direction by hydrolyzing ATP and generating an electrochemical gradient. Different forms of ATP synthases have evolved special features to meet the specific demands of the cell. Based on their specific feature, ATP... https://www.jove.com/v/11904 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12253.jpg Mechanism of Filopodia Formation Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles. Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication... https://www.jove.com/v/12253 99 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51551.jpg Aip1p Dynamics Are Altered by the R256H Mutation in Actin Disease-causing mutations in actin can alter cytoskeletal function. Cytoskeletal dynamics are quantified through imaging of fluorescently tagged proteins using total internal fluorescence microscopy. As an example, the cytoskeletal protein, Aip1p, has altered localization and movement in cells expressing the mutant actin isoform, R256H. https://www.jove.com/v/51551 537 2014-07-30T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59820.jpg Characterization at the Molecular Level using Robust Biochemical Approaches of a New Kinase Protein We characterized a new kinase protein using robust biochemical approaches: Western Blot analysis with a dedicated specific antibody on different cell lines and tissues, interactions by coimmunoprecipitation experiments, kinase activity detected by Western Blot using a phospho-specific antibody and by γ[32P] ATP labeling. https://www.jove.com/v/59820 683 2019-06-30T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61297.jpg Imaging Intranuclear Actin Rods in Live Heat Stressed Drosophila Embryos The goal of this protocol is to inject Rhodamine-conjugated globular actin into Drosophila embryos and image intranuclear actin rod assembly following heat stress. https://www.jove.com/v/61297 477 2020-05-15T21:30:00+00:00 JoVE no https://visualize.jove.com/11156102-aortic-root-replacement-by-ministernotomy-technique-and-potential-benefit monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17905/17905_article_thumb_17905.jpg Aortic Regurgitation III: Medical Management Aortic regurgitation (AR) is when the aortic valve does not close or seal properly, leading to backward blood circulation from the aorta into the left ventricle during diastole. Common causes of AR include rheumatic heart disease, congenital valve defects, and aortic root dilation. Managing AR requires a multifaceted approach to alleviate symptoms, preserve left ventricular function, and address the underlying cause of the regurgitation. Patients with symptomatic AR or significant left... https://www.jove.com/v/17905 85 2025-06-19T16:20:54+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55632.jpg Full-root Aortic Valve Replacement by Stentless Aortic Xenografts in Patients with Small Aortic Roots Full-root aortic valve replacement by stentless aortic xenograft is a viable option in patients with small aortic roots. We describe, a technique for the full-root implantation of stentless aortic xenografts, with emphasis on the management of the proximal suture line and coronary anastomoses, and discuss its limitations and alternative options. https://www.jove.com/v/55632 737 2017-05-21T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56790.jpg Standardized Technique of Aortic Valve Re-implantation for Valve-sparing Aortic Root Replacement Valve-sparing aortic root replacement has the advantage of preserving the patient's own aortic valve. The complexity of the reported techniques to date restricts their use to a limited number of cardiac surgeons. This protocol describes step-by-step a standardized technique reproducible by a greater number of cardiac surgeons. https://www.jove.com/v/56790 854 2017-12-11T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57323.jpg Technique and Patient Selection Criteria of Right Anterior Mini-Thoracotomy for Minimal Access Aortic Valve Replacement The goal of this protocol is to describe in detail the technique of minimally invasive aortic valve replacement through a right anterior mini-thoracotomy and central aortic cannulation. This technique can potentially enhance patients' comfort and, by reducing post-operative morbidity, promote lowering the length of stay and global costs. https://www.jove.com/v/57323 530 2018-03-26T22:00:00+00:00 JoVE no https://visualize.jove.com/11187624-how-can-electronic-patient-records-help-innovate-health-care monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12979.jpg Issues And Trends In Healthcare Delivery System The issues and trends in healthcare delivery are constantly changing. The COVID-19 pandemic is one recent issue that wreaked havoc on healthcare systems, causing a shortage of healthcare workers, high demand for medicines and supplies, and increased medical expenditure due to a lack of insurance. Other issues include rising healthcare costs and care fragmentation. Cost Containment Payment for healthcare services has historically promoted adoption of costly and often unnecessary or inefficient... https://www.jove.com/v/12979 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14101.jpg Purpose of Health Records I The vital purpose of health records is to provide a complete and accurate account of a patient's medical history, including communication, diagnostic and therapeutic orders, care planning, research, and quality review. Here's a breakdown of how health records serve these purposes: • Communication: Health records are a crucial communication tool among the various healthcare team members. These records help ensure patients receive the best possible care by promoting continuity of communication... https://www.jove.com/v/14101 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14104.jpg Purpose of Health Records II Health records serve various essential purposes in the healthcare system. Here are some key purposes: • Decision Analysis in Record Review: Using decision analysis in the record review process can help healthcare organizations better understand patient needs and create more effective care plans. This process allows administrators and strategic planners to analyze data from patient records and identify patterns or trends in patient care. By using these insights, healthcare organizations can... https://www.jove.com/v/14104 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14110.jpg Methods of Documentation II: POMR The Problem-Oriented Medical Record (POMR) revolutionized medical record-keeping by introducing a systematic approach focusing on the patient's problems rather than merely listing symptoms. Dr. Lawrence Weed's introduction of this method in the 1960s marked a significant advancement in medical documentation. The POMR framework consists of four key components: the database, problem list, plan of care, and progress notes. Database: This section documents crucial medical information about the... https://www.jove.com/v/14110 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14115.jpg Methods of Documentation VII: EMR Electronic Medical Records (EMRs) primarily center around electronically documenting patients' health information within a single healthcare organization or practice. They contain essential clinical data related to a patient's medical history, diagnoses, medications, treatment plans, lab results, and other pertinent information relevant to the specific encounter or episode of care. EMRs are designed to streamline documentation and workflow processes within individual healthcare settings,... https://www.jove.com/v/14115 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14125.jpg Health Information Technology and Healthcare Information System Health Information Technology (HIT) Health Information Technology, commonly called HIT, integrates advanced information systems and technology in healthcare settings. Its primary functions include: Documentation and Monitoring of Patient Care: HIT systems facilitate the efficient recording and tracking of patient data, aiding healthcare providers in monitoring patients' health status and making informed decisions. Managerial and Organizational Functions: Beyond patient care, HIT is... https://www.jove.com/v/14125 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60794.jpg Implementation of a Real-Time Psychosis Risk Detection and Alerting System Based on Electronic Health Records using CogStack We demonstrate how to deploy a real-time psychosis risk calculation and alerting system based on CogStack, an information retrieval and extraction platform for electronic health records. https://www.jove.com/v/60794 451 2020-05-15T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61899.jpg Digital Home-Monitoring of Patients after Kidney Transplantation: The MACCS Platform The MACCS platform is a comprehensive telemedicine concept aiming at better outcomes after kidney transplantation by sharing key medical information between patients and physicians. A telemedicine team reviews incoming data to detect potential complications and to improve adherence in kidney transplant recipients to achieve better long-term outcomes. https://www.jove.com/v/61899 433 2021-04-12T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61971.jpg TBase - an Integrated Electronic Health Record and Research Database for Kidney Transplant Recipients TBase combines an electronic health record with an innovative research database for kidney transplant recipients. TBase is built upon an in-memory database platform, connected to different hospital systems, and used for regular outpatient care. It automatically integrates all relevant clinical data including transplantation-specific data creating a unique research database. https://www.jove.com/v/61971 540 2021-04-13T19:30:00+00:00 JoVE no https://visualize.jove.com/11206211-adults-strategy-choices-for-simple-addition-effects-of-retrieval-interference monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18173.jpg Chunking and Rehearsal in Sensory Memory Improving short-term memory can be achieved through techniques like chunking and rehearsal. Chunking involves organizing information into larger, more manageable units. This technique is particularly useful for information that exceeds the typical memory span of between five and nine items. For instance, logging into an online account with a password like "ta89vq0179gz" involves grouping letters and numbers into three chunks—ta89, vq01, and 79gz. It makes large amounts of information more... https://www.jove.com/v/18173 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18179.jpg Retrieval Retrieval is the process of getting information out of memory storage and back into conscious awareness. This ability is essential for daily tasks like brushing hair and teeth, driving to work, and performing job duties. Retrieval occurs in three ways: recall, recognition, and relearning. Recall involves accessing information without cues, such as during an essay test, where individuals must retrieve facts and concepts from memory unaided. Another example is remembering the name of a colleague... https://www.jove.com/v/18179 72 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18189.jpg Forgetting Forgetting is an intrinsic aspect of human memory, characterized by the gradual loss or inaccessibility of information over time. Hermann Ebbinghaus, a pioneering psychologist, extensively studied this phenomenon and formulated the forgetting curve. This curve illustrates that memory loss occurs rapidly immediately after learning and then decelerates over time. Several mechanisms contribute to forgetting, including encoding failure, storage decay, retrieval failure, and interference. Encoding... https://www.jove.com/v/18189 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18190.jpg Interference and Decay Forgetting is a complex cognitive phenomenon influenced by several factors, among which interference and decay are particularly prominent. These processes explain why individuals often struggle to retrieve specific information from memory, leading to lapses in recall that can be observed in everyday situations. Interference occurs when competing memories hinder the retrieval of particular information. It can be classified into two types: proactive and retroactive interference. Proactive... https://www.jove.com/v/18190 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18192.jpg Chunking Chunking is a powerful cognitive technique that improves short-term memory retention by organizing information into smaller, more manageable units. The brain, limited by working memory capacity, can more easily process and store information when it is divided into "chunks" rather than presented as discrete, unrelated elements. Chunking is especially useful when dealing with large amounts of information, such as numerical sequences, words, or complex ideas. The principle behind chunking is... https://www.jove.com/v/18192 72 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18193.jpg Elaborative Rehearsals Elaborative rehearsal is a crucial cognitive strategy that strengthens information encoding in long-term memory by making meaningful connections between new data and pre-existing knowledge. This approach contrasts with maintenance rehearsal, which involves simple repetition without delving into the significance of the information. While maintenance rehearsal might temporarily keep information active in short-term memory, it is less effective for long-term retention. The effectiveness of... https://www.jove.com/v/18193 67 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52374.jpg A Dual Task Procedure Combined with Rapid Serial Visual Presentation to Test Attentional Blink for Nontargets This paper describes a novel dual task procedure combined with Rapid Serial Visual Presentation to look at attentional blink at varied stimulus onset asynchronies. This experimental procedure differed from others in that it tested attentional blink for nontargets. https://www.jove.com/v/52374 525 2014-12-05T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56097.jpg A Prediction Error-driven Retrieval Procedure for Destabilizing and Rewriting Maladaptive Reward Memories in Hazardous Drinkers This manuscript describes a memory retrieval procedure for destabilizing robust reward memories and rewriting them with counterconditioning prior to their reconsolidation. https://www.jove.com/v/56097 485 2018-01-05T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60026.jpg Using Practice Testing, Public Speaking, and Source Monitoring to Examine the Influences of Learning Strategies and Stress on Episodic Memory The present experiment combined three experimental procedures — a retrieval-practice learning manipulation, a list-discrimination task, and a stress-induction technique — to examine the influences of different learning strategies and acute stress on multiple measures of episodic memory. https://www.jove.com/v/60026 479 2019-06-14T22:00:00+00:00 JoVE no https://visualize.jove.com/11210392-a-look-at-the-safety-profile-of-over-the-counter-naproxen-sodium-a-meta-analysis monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15044.jpg Antianginal Drugs: Nitrates and β-Blockers In cardiovascular health, antianginal drugs combat angina pectoris — a condition marked by chest pain owing to diminished blood flow to the heart. Organic nitrates, such as nitroglycerin, play a pivotal role. Once metabolized, they liberate nitric oxide, a molecular marvel. Nitric oxide triggers guanylyl cyclase and augments cGMP production. This biochemical cascade orchestrates the relaxation of vascular smooth muscles, ushering in vasodilation and enhancing coronary blood flow. Administered... https://www.jove.com/v/15044 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15045.jpg Antianginal Drugs: Calcium Channel Blockers and Ranolazine Angina pectoris, a primary symptom of ischemic heart disease, requires careful pharmacological interventions. In this context, calcium channel blockers (CCBs) and ranolazine have emerged as crucial pharmacotherapeutic agents, providing deep insights into the complexities of angina management. CCBs, a diverse class that includes dihydropyridines (nifedipine) and diphenylalkylamines (verapamil and diltiazem), exert their effect by blocking calcium channels in cardiac and smooth muscle cells. This... https://www.jove.com/v/15045 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16592.jpg Model-Independent Approaches for Pharmacokinetic Data: Noncompartmental Analysis Noncompartmental analyses offer an alternative method for describing drug pharmacokinetics without relying on a specific compartmental model. In this approach, the drug's pharmacokinetics are assumed to be linear, with the terminal phase log-linear. This assumption allows for simplified analysis and interpretation of the drug's behavior in the body. One important characteristic of noncompartmental analyses is that drug exposure increases proportionally with increasing doses. This relationship... https://www.jove.com/v/16592 59 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16598.jpg Nonlinear Pharmacokinetics: Overview Nonlinear or dose-dependent pharmacokinetics is a phenomenon that occurs when the pharmacokinetic parameters of certain drugs deviate from linear pharmacokinetics at higher doses. These drugs do not follow the expected first-order kinetics, where the rate of drug elimination is directly proportional to the drug concentration. Instead, they exhibit a nonlinear relationship, which can be attributed to several factors. Nonlinearity can arise due to the saturation of plasma protein-binding or... https://www.jove.com/v/16598 79 JoVE no https://cloudfront.jove.com/files/ftp_upload/17262/17262_article_thumb_17262.jpg Drug Toxicity: Risk factors Adverse Drug Reactions (ADRs) are potential complications that arise during pharmacotherapy, influenced by multiple risk factors. Age plays a significant role; both neonates and the elderly are at heightened risk due to their respective immature and diminished metabolic and elimination processes. Gender also impacts ADRs, with females experiencing a 1.5 to 1.7-fold greater risk than males, which may be linked to pharmacokinetic, pharmacodynamic, and hormonal differences. Notably, neonates, the... https://www.jove.com/v/17262 84 2026-02-12T19:17:22+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17269/17269_article_thumb_17269.jpg Drug toxicity: Drug–Drug Interaction Drug–drug interactions can precipitate toxicity through multiple mechanisms. Absorption interactions alter how drugs enter the body, exemplified when ranitidine increases the absorption of basic drugs, while cholestyramine decreases the levels of propranolol. Protein binding interactions occur when drugs share the same binding sites on plasma proteins. Drugs like aspirin and warfarin, when bound in excess, can lead to increased free drug concentrations, enhancing the potential for... https://www.jove.com/v/17269 90 2026-02-12T19:16:59+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64571.jpg Synthesis of a Borylated Ibuprofen Derivative Through Suzuki Cross-Coupling and Alkene Boracarboxylation Reactions The present protocol describes a detailed benchtop catalytic method that yields a unique borylated derivative of... https://www.jove.com/v/64571 536 2022-11-30T22:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64660.jpg Meta-Analysis of the Effectiveness and Safety of Shugan Jieyu Capsules for the Treatment of Insomnia The presented protocol describes an investigation strategy and systematic review to evaluate the clinical effectiveness and safety of Shugan Jieyu capsules for treating insomnia. https://www.jove.com/v/64660 274 2023-02-17T20:30:00+00:00 JoVE no https://visualize.jove.com/11247832-effect-of-repetitive-icv-injections-of-ang-ii-on-c-fos-and-at1-receptor-expression-in-the-rat-brain monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15023.jpg Antihypertensive Drugs: Angiotensin-Converting Enzyme Inhibitors Angiotensin-converting enzyme (ACE), a vital component of the renin-angiotensin-aldosterone system, is abundant in lung endothelial cells. ACE converts the inactive decapeptide, angiotensin I, into the active octapeptide, angiotensin II. This potent vasoconstrictor narrows blood vessels, increasing resistance to blood flow and elevating blood pressure. Angiotensin II also stimulates aldosterone production, encouraging kidney cells to reabsorb more sodium and water from urine, thereby increasing... https://www.jove.com/v/15023 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15037.jpg Heart Failure Drugs: Inhibitors of Renin-Angiotensin System The activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) contributes to cardiac remodeling, and inhibiting the RAAS is a pharmacological target in heart failure management. As a result, neurohumoral modulation is a crucial treatment principle for managing heart failure. This approach involves using medications like ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), β-blockers, mineralocorticoid receptor antagonists (MRAs), and neutral... https://www.jove.com/v/15037 86 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53866.jpg Receptor Autoradiography Protocol for the Localized Visualization of Angiotensin II Receptors Here we present a protocol to describe the localization of angiotensin II Type 1 receptors in the rat brain by quantitative, densitometric, in vitro receptor autoradiography using an iodine-125 labeled analog of angiotensin II. https://www.jove.com/v/53866 723 2016-06-07T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54170.jpg Continuous IV Infusion is the Choice Treatment Route for Arginine-vasopressin Receptor Blocker Conivaptan in Mice to Study Stroke-evoked Brain Edema Our studies have revealed that the beneficial effects of conivaptan are dependent on the method of delivery after experimental stroke in mice. We have developed a research protocol for delivery of the receptor blocker via IV catheter on stroke-evoked brain edema formation in mice. https://www.jove.com/v/54170 524 2016-09-01T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59439.jpg Non-invasive Strategies for Chronic Manipulation of DREADD-controlled Neuronal Activity Here we describe two non-invasive methods to chronically control neuronal activity using chemogenetics in mice. Eye-drops were used to deliver clozapine-N-oxide (CNO) daily. We also describe two methods for prolonged administration of CNO in drinking water. These strategies for chronic neuronal control require minimal intervention reducing animals’ stress. https://www.jove.com/v/59439 508 2019-08-25T22:00:00+00:00 JoVE no https://visualize.jove.com/11321511-repetitive-apneas-reduce-nonlinear-dynamical-complexity-of-the-human-cardiovascular-control-system monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13301.jpg Respiratory Volumes and Capacities I Assessing the respiratory rate and rhythm for a complete minute is crucial for evaluating the breathing pattern. Even a minor increase in the patient's average respiratory rate, by as little as three to five breaths per minute, is an early and vital indicator of respiratory distress. Patients with a respiratory rate exceeding twenty-four breaths per minute require close monitoring to determine the physiological alterations. This careful observation is essential for prompt recognition and... https://www.jove.com/v/13301 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13831.jpg Physiological Control of Respiration Introduction Breathing, a seemingly passive process, is regulated by the respiratory center in the brainstem. This center coordinates the involuntary control of respirations, which means it occurs without conscious effort, ensuring a smooth and uninterrupted pattern. Regulation of Ventilation The body maintains ventilation by monitoring levels of carbon dioxide (CO2), oxygen (O2), and hydrogen ion concentration (pH) in the arterial blood. Among these factors, the level of CO2 plays a crucial... https://www.jove.com/v/13831 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15706.jpg Neural Control of Respiration The neural regulation of respiration is a meticulously coordinated process primarily controlled by the respiratory centers located within the brainstem. These centers, composed of specialized neurons, transmit nerve impulses that control the contraction and relaxation of our respiratory muscles. Respiratory Centers in the Brainstem Two primary areas comprise the respiratory center: the medullary respiratory center in the medulla oblongata and the pontine respiratory group in the pons. The... https://www.jove.com/v/15706 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15708.jpg Other Factors Affecting Respiration Centers Breathing is primarily an involuntary activity regulated by the brainstem respiratory centers. However, it can also be consciously controlled, allowing us to hold our breath or take deeper breaths when needed. This voluntary control is facilitated by the cerebral motor cortex, which bypasses the medullary centers to stimulate the respiratory muscles directly. However, the ability to hold one's breath voluntarily is not limitless. When the CO2 concentration in the blood reaches a critical level,... https://www.jove.com/v/15708 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16326.jpg Physiology of Respiration II: Neurogenic Control of Respiration The neurogenic control of respiration coordinates various neural networks and pathways to regulate breathing rate and depth, meeting the body's oxygen and carbon dioxide exchange requirements. This system adapts to physiological and environmental conditions, ensuring optimal breathing patterns. Central Control The brainstem is the primary site of central control, hosting respiratory centers: • The Medullary Respiratory Center, comprising the dorsal respiratory group or DRG and the ventral... https://www.jove.com/v/16326 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17797.jpg Sleep Apnea Sleep apnea is a condition where breathing stops intermittently during sleep, often leading to significant health issues. Each episode can last from 10 to 20 seconds or more and is frequently accompanied by a brief arousal from sleep. This disturbance, largely unnoticed by the individual, can lead to severe daytime fatigue. Commonly, individuals seek help after being informed by their partners about loud snoring and noticeable breathing pauses during sleep. The condition is more prevalent among... https://www.jove.com/v/17797 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51082.jpg Assessing Cerebral Autoregulation via Oscillatory Lower Body Negative Pressure and Projection Pursuit Regression Cerebral perfusion is maintained across a range of pressures via cerebral autoregulation. However, characterizing autoregulation requires prominent pressure fluctuations at regulated frequencies. The described protocol will show how oscillatory lower body negative pressure can generate pressure fluctuations to provide data for projection pursuit regression for quantification of the autoregulatory curve. https://www.jove.com/v/51082 686 2014-12-10T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54933.jpg A Model to Simulate Clinically Relevant Hypoxia in Humans Hypoxia simulation in humans has usually been performed by inhaling hypoxic gas mixtures. For this study, apneic divers were used to simulate dynamic hypoxia in humans. Additionally, physiological changes in desaturation and re-saturation kinetics were evaluated with non-invasive tools such as Near-Infrared-Spectroscopy (NIRS) and peripheral oxygenation saturation (SpO2). https://www.jove.com/v/54933 594 2016-12-22T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66733.jpg Custom Smartphone Application to Guide Locomotor-Respiratory Coupling in the Field Using Step-Adaptive Breathing Sounds Locomotor-respiratory coupling (LRC) is potentially advantageous for runners but may be difficult to perform. We introduce a custom solution implemented on a smartphone to individualize and guide runners toward LRC. https://www.jove.com/v/66733 386 2024-09-27T20:10:00+00:00 JoVE no https://visualize.jove.com/11323047-three-dimensional-magnetic-resonance-imaging-of-fetal-brains monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13865.jpg Magnetic Resonance Imaging Magnetic resonance imaging (MRI) is a noninvasive medical imaging technique based on a phenomenon of nuclear physics discovered in the 1930s, in which matter exposed to magnetic fields and radio waves was found to emit radio signals. In 1970, a physician and researcher named Raymond Damadian noticed that malignant (cancerous) tissue gave off different signals than normal body tissue. He applied for a patent for the first MRI scanning device in clinical use by the early 1980s. The early MRI... https://www.jove.com/v/13865 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17752.jpg Brain Imaging Brain imaging technologies provide critical insights into both the structure and function of the human brain, enabling medical professionals and researchers to diagnose, study, and treat neurological disorders or psychiatric disorders more effectively. These technologies include computerized axial tomography (CAT or CT scans), positron-emission tomography (PET scans), magnetic resonance imaging (MRI), functional magnetic resonance imaging (fMRI), and Transcranial Magnetic Stimulation (TMS).<br... https://www.jove.com/v/17752 74 JoVE no https://cloudfront.jove.com/files/ftp_upload/17884/17884_article_thumb_17884.jpg Imaging Studies for Cardiovascular System IV: CMRI Cardiovascular magnetic resonance imaging, or CMRI, is a non-invasive diagnostic test that employs a magnetic field and radiofrequency waves to create precise images of the heart and arteries. It provides comprehensive information about cardiac anatomy, function, perfusion, and tissue characterization without ionizing radiation.IndicationsCMRI diagnoses various heart conditions, including tissue damage from heart attacks, ischemic heart disease, myocarditis, aortic issues (tears, aneurysms,... https://www.jove.com/v/17884 81 2025-06-19T16:07:57+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18491/18491_article_thumb_18491.jpg Imaging Studies IV: Magnetic Resonance Imaging Introduction:Magnetic Resonance Imaging, or MRI, can include a specialized imaging technique of the urinary system known as Magnetic Resonance Urography (MRU). This radiation-free technique uses strong magnetic fields and radio waves to produce detailed images with the help of a computer. MRU is particularly effective for visualizing fluid-filled structures like the kidneys, ureters, and bladder.Applications of MRI in the Genitourinary SystemKidneys and Ureters: MRI detects tumors, cysts,... https://www.jove.com/v/18491 87 2025-06-19T16:29:57+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61953.jpg Human Fetal Blood Flow Quantification with Magnetic Resonance Imaging and Motion Compensation Here we present a protocol for measuring fetal blood flow rapidly with MRI and retrospectively performing motion correction and cardiac gating. https://www.jove.com/v/61953 416 2021-01-07T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64096.jpg Whole-Brain Single-Cell Imaging and Analysis of Intact Neonatal Mouse Brains Using MRI, Tissue Clearing, and Light-Sheet Microscopy This protocol describes methods for conducting magnetic resonance imaging, clearing, and immunolabeling of intact mouse brains using iDISCO+, followed by a detailed description of imaging using light-sheet microscopy, and downstream analyses using NuMorph. https://www.jove.com/v/64096 529 2022-08-01T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65180.jpg Micro-CT Imaging and Morphometric Analysis of Mouse Neonatal Brains This study describes the steps for obtaining high-resolution images of neonatal mouse brains by combining micro-computed tomography (micro-CT) and a contrast agent in ex vivo samples. We describe basic morphometric analyses to quantify brain size and shape in these images. https://www.jove.com/v/65180 396 2023-05-19T21:00:00+00:00 JoVE no https://visualize.jove.com/11338411-posterior-cerebral-artery-wada-test-sodium-amytal-distribution-and-functional-deficits monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1978.jpg Focal Cerebral Ischemia Model by Endovascular Suture Occlusion of the Middle Cerebral Artery in the Rat Surgical induction of ischemic brain damage in the rat is a widely used model for stroke research. Here we demonstrate the induction of focal cerebral ischemia by occlusion of the middle cerebral artery. Visualization of the resulting infarct by histological staining and magnetic resonance imaging is also shown. https://www.jove.com/v/1978 830 2011-02-06T01:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51495.jpg Non-invasive Imaging and Analysis of Cerebral Ischemia in Living Rats Using Positron Emission Tomography with 18 F-FDG Brain damage resulting from cerebral ischemia may be non-invasively imaged and studied in rats using pre-clinical positron emission tomography coupled with the injectable radioactive probe, 18F-fluorodeoxyglucose. Further, the use of modern software tools that include volume of interest (VOI) brain templates dramatically increase the quantitative information gleaned from these studies. https://www.jove.com/v/51495 631 2014-12-28T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65857.jpg Transient Middle Cerebral Artery Occlusion Model of Stroke This protocol describes the model of transient focal cerebral ischemia in mice through intraluminal occlusion of the middle cerebral artery. Additionally, examples of outcome assessment are shown using magnetic resonance imaging and behavioral tests. https://www.jove.com/v/65857 332 2023-08-11T21:40:00+00:00 JoVE no https://visualize.jove.com/11377905-cellular-reaction-on-the-anterior-surface-of-4-types-of-intraocular-lenses monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14480.jpg Glaucoma: Overview Glaucoma is an eye condition characterized by increased intraocular pressure that damages the retina and optic nerve, leading to irreversible blindness if left untreated. The human eye has various components, including the cornea, iris, pupil, lens, and optic nerve. Aqueous humor is secreted by the epithelium of the ciliary body in the posterior chamber and flows through the trabecular meshwork and canal of Schlemm, maintaining normal intraocular pressure. The trabecular meshwork and the canal... https://www.jove.com/v/14480 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14481.jpg Open Angle Glaucoma: Treatment In open-angle glaucoma, the iridocorneal angle remains open, but the trabecular meshwork becomes stiff, slowing down the outflow of aqueous humor. This causes a buildup of aqueous humor in the anterior chamber, leading to a sudden increase in intraocular pressure. The treatment for open-angle glaucoma focuses on reducing the elevated intraocular pressure by either decreasing the secretion of aqueous humor or increasing its outflow. Drugs such as carbonic anhydrase inhibitors, α2- and... https://www.jove.com/v/14481 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14482.jpg Angle Closure Glaucoma: Treatment Angle-closure glaucoma, or closed-angle glaucoma, is an eye condition where the iris bulges out and blocks the iridocorneal angle, resulting in a buildup of aqueous humor and increased intraocular pressure. Immediate medical attention is necessary due to the sudden onset of symptoms. The treatment for angle-closure glaucoma includes short-term and long-term approaches. Short-term treatment involves using eye drops like pilocarpine to lower intraocular pressure by increasing aqueous humor... https://www.jove.com/v/14482 88 JoVE no https://cloudfront.jove.com/files/ftp_upload/17259/17259_article_thumb_17259.jpg Ophthalmic Drug Delivery Systems Ophthalmic drug delivery faces major limitations due to poor absorption across the corneal membrane. This process is primarily driven by diffusion and is influenced by two main factors: the physicochemical properties of the drug and tear drainage. Most ophthalmic drugs, such as pilocarpine, epinephrine, atropine, and local anesthetics, are weak bases. They are typically formulated at an acidic pH to enhance chemical stability. However, this leads to high ionization, reducing their ability to... https://www.jove.com/v/17259 83 2026-02-12T19:16:56+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53907.jpg Development of an In Vitro Ocular Platform to Test Contact Lenses Current in vitro models for evaluating contact lenses (CLs) and other eye-related applications are severely limited. The presented ocular platform simulates physiological tear flow, tear volume, air exposure and mechanical wear. This system is highly versatile and can be applied to various in vitro analyses with CLs. https://www.jove.com/v/53907 508 2016-04-06T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58590.jpg Synthesis of Soft Polysiloxane-urea Elastomers for Intraocular Lens Application This study describes synthetic routes for aminopropyl-terminated polydimethylsiloxanes and polydimethyl-methyl-phenyl-siloxane-block copolymers and for soft polysiloxane-based urea (PSU) elastomers. It presents the application of PSUs as accommodating an intraocular lens. An evaluation method for in vitro cytotoxicity is also described. https://www.jove.com/v/58590 709 2019-03-08T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65419.jpg Rotating the Intraocular Lens to Prevent Posterior Capsular Opacification in Cataract Surgeries The present protocol describes removing residual epithelial cells by rotating the intraocular lens in extracapsular cataract surgery without extra tools for preventing posterior capsular opacification. https://www.jove.com/v/65419 299 2023-07-07T21:10:00+00:00 JoVE no https://visualize.jove.com/11395322-an-automated-method-for-registering-and-quantifying-scratching-activity-in-mice-use-for-drug-evaluation monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/51212.jpg Measuring Changes in Tactile Sensitivity in the Hind Paw of Mice Using an Electronic von Frey Apparatus Electronic von Frey measurements are an effective and improved alternative to classical von Frey filaments, as they allow rapid and precise measurement of changes in rodent mechanical withdrawal thresholds to continuously applied pressure stimuli before and after an inflammatory event. https://www.jove.com/v/51212 469 2013-12-19T22:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58943.jpg Cheek Injection Model for Simultaneous Measurement of Pain and Itch-related Behaviors Typically, the mouse neck injection model is used for evaluate pruritogen-induced scratch behaviors. However, the model provides information only on itch, not pain. Here, a cheek injection model is introduced in mice which can be used to simultaneously measure pain and itch-related behaviors. https://www.jove.com/v/58943 299 2019-09-27T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63454.jpg Mechanical Conflict-Avoidance Assay to Measure Pain Behavior in Mice The mechanical conflict-avoidance assay is used as a non-reflexive readout of pain sensitivity in mice which can be used to better understand affective-motivational responses in a variety of mouse pain models. https://www.jove.com/v/63454 417 2022-02-18T22:15:00+00:00 JoVE no https://visualize.jove.com/11445137-cognitive-effects-of-insulin-in-the-central-nervous-system monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4451.jpg Hippocampal Insulin Microinjection and In vivo Microdialysis During Spatial Memory Testing Modulation of hippocampally-dependent spatial working memory by direct intrahippocampal microinjection, accompanied and followed by in vivo microdialysis for metabolites in conscious, behaving animals. https://www.jove.com/v/4451 632 2013-01-12T01:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12220.jpg Insulin Secretory Vesicles Insulin secretory vesicles release insulin to stimulate blood glucose uptake and regulate carbohydrate metabolism. When the blood glucose levels increase, glucose enters the pancreatic β-islet cells through glucose transporters. Once inside, glucose is metabolized through glycolysis, the citric acid cycle, and the electron transport chain, producing ATP. This increase in ATP concentration closes ATP-sensitive potassium channels, leading to depolarization of the membrane and the opening of... https://www.jove.com/v/12220 65 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14992.jpg Hormones Regulating Blood Glucose Insulin is released by beta cells of the pancreas when blood glucose levels are high. It facilitates glucose absorption and utilization in insulin-dependent cells with insulin receptors on their plasma membranes. Insulin promotes glucose uptake by increasing the number of glucose transport proteins in the cell membrane, allowing glucose to enter the cell. As a result, glucose utilization and ATP production are enhanced. In addition to accelerating glucose uptake and utilization, insulin has... https://www.jove.com/v/14992 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17292.jpg Glucose Homeostasis: Pancreatic Islets and Insulin Secretion The pancreatic islets comprising only 1%-2% of the volume are highly vascularized and innervated mini-organs. They contain five endocrine cell types, including β cells that secrete insulin, which is synthesized as a single polypeptide chain, preproinsulin, processed to proinsulin, and finally to insulin and C-peptide. This process is complex and regulated, involving the Golgi complex, the endoplasmic reticulum, and the secretory granules of the β cell. Insulin and C-peptide are co-secreted in... https://www.jove.com/v/17292 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17293.jpg Insulin: The Receptor and Signaling Pathways Insulin action is mediated through a receptor tyrosine kinase, akin to the IGF-1 receptor. The number of receptors per cell varies significantly, from 40 on erythrocytes to 300,000 on adipocytes and hepatocytes. The insulin receptor consists of linked α/β subunit dimers, forming a heterotetramer glycoprotein with two extracellular α subunits and two β subunits spanning the membrane. The α subunits inhibit the inherent tyrosine kinase activity of the β subunits, but this inhibition is released... https://www.jove.com/v/17293 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17299.jpg Insulin: Dosing Regimen and Adverse Effects Insulin-replacement therapy usually includes both long-acting insulin (basal) and short-acting insulin (to cater to postprandial needs). In a diverse group of type 1 diabetes patients, the average daily insulin dose is typically 0.5-0.7 units/kg body weight. However, obese patients and pubertal adolescents may need more due to insulin resistance. The basal dose constitutes about 40%-50% of the total daily dose, with the rest as premeal insulin. The mealtime insulin dose should mirror... https://www.jove.com/v/17299 76 JoVE no https://cloudfront.jove.com/files/ftp_upload/40902/40902_article_thumb_40902.jpg Type II Diabetes II: Pathophysiology PathophysiologyType 2 diabetes mellitus (T2DM ) is a chronic metabolic disorder characterized by insulin resistance and progressive pancreatic β-cell dysfunction, leading to impaired glucose homeostasis. It results from interactions among genetic predisposition, environmental factors, and metabolic stressors, such as overnutrition and a sedentary lifestyle.Insulin Resistance and Glucose DysregulationEarly T2DM involves insulin resistance in skeletal muscle, adipose tissue, and the liver. https://www.jove.com/v/40902 84 2026-04-15T15:51:43+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56409.jpg Live Images of GLUT4 Protein Trafficking in Mouse Primary Hypothalamic Neurons Using Deconvolution Microscopy This protocol describes a technique for observation of real-time Green Fluorescence Protein (GFP) tagged Glucose Transporter 4 (GLUT4) protein trafficking upon insulin stimulation and characterization of the biological role of CCR5 in the insulin–GLUT4 signaling pathway with Deconvolution Microscopy. https://www.jove.com/v/56409 527 2017-12-07T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56410.jpg Studying the Hypothalamic Insulin Signal to Peripheral Glucose Intolerance with a Continuous Drug Infusion System into the Mouse Brain This protocol studies the role of chemokine (C-C motif) ligand 5 (CCL5) in the hypothalamus by delivering an antagonist, MetCCL5, into the mouse brain using a micro-osmotic pump brain infusion system. This transient inhibition of CCL5 activity interrupted hypothalamic insulin signaling, leading to glucose intolerance and peripheral systemic insulin sensitivity. https://www.jove.com/v/56410 512 2018-01-04T20:30:00+00:00 JoVE no https://visualize.jove.com/11452112-the-art-of-the-probable-system-control-in-the-adaptive-immune-system monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4454.jpg Trans-vivo Delayed Type Hypersensitivity Assay for Antigen Specific Regulation We describe a valuable diagnostic assay that could potentially be used to decide the withdrawal of immunosuppression after transplant without elevated risk of graft rejection. The assay uses the principles of Delayed Type Hypersensitivity and provides accurate assessment of both donor specific effector and regulatory immune responses mounted by recipients. https://www.jove.com/v/4454 709 2013-05-02T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10895.jpg What is the Immune System? Overview The immune system comprises diverse biological structures and processes that protect the body from disease. These processes can be classified into innate and adaptive immunity. To work effectively, the immune system needs to detect pathogens by distinguishing the body’s own structures from foreign elements. If this determination fails, autoimmune diseases occur in which the immune system reacts against the body’s own tissue. The Innate Immune System Acts Fast and Non-specifically <br... https://www.jove.com/v/10895 98 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10896.jpg Cell-mediated Immune Responses Overview The cell-mediated immune system is the host’s primary response against invasive bacteria and viruses that cause intracellular infections. It is also essential for fighting against and destroying cancer cells. Furthermore, the cell-mediated immune system plays a role in the rejection of organ transplants or graft tissue. The Innate Immune System Activates the Adaptive Immune System Phagocytic cells of the innate immune system, such as macrophages or dendritic cells, are the first to... https://www.jove.com/v/10896 100 2025-10-23T18:49:07+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15333.jpg Introduction to Innate and Adaptive Immunity The human immune system is a complex defense mechanism that protects the body from harmful pathogens and foreign substances. It comprises two crucial components: innate and adaptive immunity. Innate immunity is the body's natural, nonspecific defense system that acts quickly to protect against pathogens. It incorporates physical barriers like skin and mucous membranes and cellular elements such as phagocytes and natural killer cells. This part of our immune system provides an immediate,... https://www.jove.com/v/15333 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15339.jpg Special Features of Adaptive Immunity The adaptive immune system, a crucial component of the overall immune response, offers a highly specialized defense against pathogens. It involves specific cell types and features, enabling it to combat infections effectively and efficiently. The primary cell types involved in adaptive immunity are T cells and B cells. Each type has a unique role in defending the body against pathogens. T cells are responsible for cell-mediated immunity. They identify and eliminate infected cells directly,... https://www.jove.com/v/15339 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15341.jpg Antigens Involved in Adaptive Immunity An antigen is any substance the immune system identifies as foreign and potentially harmful to the body, prompting an immune response. Antigens have two functional properties: immunogenicity and reactivity. Immunogenicity is the ability of an antigen to stimulate a specific immune response. At the same time, reactivity describes the antigen's ability to react with the cells and antibodies produced in response to it. Complete Antigens Complete antigens possess both immunogenicity and reactivity. https://www.jove.com/v/15341 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15355.jpg Immune Response Against Viral Pathogens The immune system's response to viral infections is a complex and coordinated process involving natural killer (NK) cells, T cell-mediated responses, and antibody-mediated responses. NK Cells NK cells are a crucial part of our innate immune system, acting as the first line of defense against viral infections. These cells can recognize and kill infected cells without prior exposure to the virus, effectively slowing down the spread of infection. Additionally, NK cells produce proinflammatory... https://www.jove.com/v/15355 89 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55283.jpg Measurement of T Cell Alloreactivity Using Imaging Flow Cytometry This paper describes a method for measuring alloreactivity in a mixed population of T cells using imaging flow cytometry. https://www.jove.com/v/55283 544 2017-04-19T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66939.jpg Identification of Rare Antigen-Specific T Cells from Mouse Lungs with Peptide:Major Histocompatibility Complex Tetramers We provide a detailed protocol for isolating and identifying rare antigen-specific T cell populations in mouse lungs through magnetic bead-based T cell enrichment and peptide:major histocompatibility complex (MHC) tetramers. https://www.jove.com/v/66939 555 2024-07-19T21:40:00+00:00 JoVE no https://visualize.jove.com/11470887-a-new-approach-for-filtering-noise-from-high-density-oligonucleotide-microarray-datasets monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1471.jpg Global Gene Expression Analysis Using a Zebrafish Oligonucleotide Microarray Platform Gene microarrays are powerful tools in gene expression profiling at a genome-wide level. This technology has application in a variety of biological disciplines including developmental biology and toxicology. In this video, we detail a protocol for global gene expression analysis using a comprehensive oligonucleotide microarray platform for the zebrafish. https://www.jove.com/v/1471 794 2009-08-10T07:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/1622.jpg A Rapid High-throughput Method for Mapping Ribonucleoproteins (RNPs) on Human pre-mRNA Due to the transient nature of pre-mRNA, it can be difficult to isolate and study in vivo. Here, we present a novel in vitro approach to investigate RNA-protein interactions using a synthetic oligo pool that tiles across selected regions of pre-mRNA. https://www.jove.com/v/1622 780 2009-12-02T23:46:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/2864.jpg Competitive Genomic Screens of Barcoded Yeast Libraries We have developed comprehensive, unbiased genome-wide screens to understand gene-drug and gene-environment interactions. Methods for screening these mutant collections are presented. https://www.jove.com/v/2864 719 2011-08-11T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12014.jpg DNA Microarrays Microarrays are high-throughput and relatively inexpensive assays that can be automated to analyze large quantities of data at a time. They are used in genome-wide studies to compare gene or protein expression under two varied conditions, such as healthy and diseased states. Microarrays consist of glass or silica slides on which probe molecules are covalently attached through surface functionalization. Most commonly, the slides are prepared through the chemisorption of silanes to silica... https://www.jove.com/v/12014 154 JoVE no https://visualize.jove.com/11489134-structure-activity-and-evolution-of-the-group-i-thiolactone-peptide-quorum-sensing-system-of-staphylococcus-aureus monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10713.jpg Bacterial Signaling Bacterial signaling can occur within bacteria (intracellular) or between bacteria (intercellular). At times, a group of bacteria behaves like a community. To achieve this, they engage in quorum sensing, the perception of higher cell density that causes changes in gene expression. Quorum sensing involves both extracellular and intracellular signaling. The signaling cascade starts with a molecule called an autoinducer (AI). Individual bacteria produce AIs that move out of the bacterial cell... https://www.jove.com/v/10713 90 JoVE no https://cloudfront.jove.com/files/ftp_upload/19504/19504_article_thumb_19504.jpg Formation of Lipopolysaccharides Lipopolysaccharides (LPS) are crucial components of the outer membrane of Gram-negative bacteria, serving both structural and functional roles. It contributes to membrane stability and protects bacteria from host immune responses. LPS is composed of three major regions—lipid A, a core oligosaccharide, and an O antigen. The biosynthesis and assembly of LPS involve a highly coordinated set of enzymatic reactions and transport mechanisms. Additionally, LPS is recognized as an endotoxin, triggering... https://www.jove.com/v/19504 79 2025-06-12T16:39:09+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19537/19537_article_thumb_19537.jpg Global Regulatory Systems Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource... https://www.jove.com/v/19537 88 2025-06-12T16:15:04+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19539/19539_article_thumb_19539.jpg Gene Regulation in Microbial Communities: Quorum Sensing Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,... https://www.jove.com/v/19539 88 2025-06-12T16:15:28+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40813/40813_article_thumb_40813.jpg Regulation of Bacterial Virulence Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental... https://www.jove.com/v/40813 88 2026-03-12T20:36:13+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40819/40819_article_thumb_40819.jpg Staphylococcal Skin Infections Staphylococcus aureus is a Gram-positive coccus that resides harmlessly on the skin and mucous membranes of healthy individuals. When the skin barrier is breached, it can shift from a commensal to an opportunistic pathogen. This transition is facilitated by surface adhesins, such as clumping factor B and S. aureus surface protein G (SasG), which bind to structural proteins, including loricrin and cytokeratin, in the damaged epidermis. Protein A, another key factor, binds the Fc region of... https://www.jove.com/v/40819 89 2026-03-12T20:35:44+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50788.jpg Studying Interactions of Staphylococcus aureus with Neutrophils by Flow Cytometry and Time Lapse Microscopy We present methods to study the effect of PSMs and other toxins secreted by Staphylococcus aureus on neutrophils using flow cytometry and fluorescence microscopy. https://www.jove.com/v/50788 640 2013-07-17T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59055.jpg A Fluorescence-based Method to Study Bacterial Gene Regulation in Infected Tissues Described here is a method for analyzing bacterial gene expression in animal tissues at a cellular level. This method provides a resource for studying the phenotypic diversity occurring within a bacterial population in response to the tissue environment during an infection. https://www.jove.com/v/59055 430 2019-02-19T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66582.jpg Synthesis and Assay of Vibrio Quorum Sensing Inhibitors Thiophenesulfonamide compounds are potent and specific inhibitors of Vibrio quorum sensing regulators LuxR/HapR that block their activity in vivo, thus preventing transcription of genes for virulence, motility, and biofilms. This protocol details how these compounds are synthesized, modeled in silico, and assayed in vivo for activity against LuxR/HapR. https://www.jove.com/v/66582 209 2024-05-31T20:10:00+00:00 JoVE no https://visualize.jove.com/11491284-the-rna-i-motif monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10684.jpg Nucleic acids Nucleic acids are the most important macromolecules for the continuity of life. They carry the cell's genetic blueprint and carry instructions for its functioning. DNA and RNA The two main types of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA is the genetic material in all living organisms, ranging from single-celled bacteria to multicellular mammals. It is in the nucleus of eukaryotes and in the organelles, chloroplasts, and mitochondria. In prokaryotes, the... https://www.jove.com/v/10684 163 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10799.jpg RNA Structure Overview The basic structure of RNA consists of a five-carbon sugar and one of four nitrogenous bases. Although most RNA is single-stranded, it can form complex secondary and tertiary structures. Such structures play essential roles in the regulation of transcription and translation. Different Types of RNA Have the Same Basic Structure There are three main types of ribonucleic acid (RNA): messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three RNA types consist of a... https://www.jove.com/v/10799 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11473.jpg Nucleic Acids Nucleic acids are the most important macromolecules for the continuity of life. They carry the cell's genetic blueprint and carry instructions for its functioning. DNA and RNA The two main types of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA is the genetic material in all living organisms, ranging from single-celled bacteria to multicellular mammals. It is in the nucleus of eukaryotes and in the organelles, chloroplasts, and mitochondria. In prokaryotes, the... https://www.jove.com/v/11473 163 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10799.jpg RNA Structure Overview The basic structure of RNA consists of a five-carbon sugar and one of four nitrogenous bases. Although most RNA is single-stranded, it can form complex secondary and tertiary structures. Such structures play essential roles in the regulation of transcription and translation. Different Types of RNA Have the Same Basic Structure There are three main types of ribonucleic acid (RNA): messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three RNA types consist of a... https://www.jove.com/v/11577 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12556.jpg RNA Structure The basic structure of RNA consists of a string of ribonucleotides attached by phosphodiester bonds. Although most RNA is single-stranded, it can form complex secondary and tertiary structures. Such structures play essential roles in the regulation of transcription and translation. Different Types of RNA Have the Same Basic Structure There are three main types of ribonucleic acid (RNA) involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three... https://www.jove.com/v/12556 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14371.jpg Nucleic Acid Structure The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group on the ribose's second carbon and a hydrogen on the deoxyribose's second carbon. The phosphate residue attaches to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms a 5′ to 3′ phosphodiester linkage. DNA Structure DNA has a double-helix structure. The... https://www.jove.com/v/14371 85 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56004.jpg Sample Preparation for Mass Spectrometry-based Identification of RNA-binding Regions We describe a protocol to identify RNA-binding proteins and map their RNA-binding regions in live cells using UV-mediated photocrosslinking and mass spectrometry. https://www.jove.com/v/56004 652 2017-09-28T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59913.jpg Identification of Footprints of RNA:Protein Complexes via RNA Immunoprecipitation in Tandem Followed by Sequencing (RIPiT-Seq) Here, we present a protocol to enrich endogenous RNA binding sites or "footprints" of RNA:protein (RNP) complexes from mammalian cells. This approach involves two immunoprecipitations of RNP subunits and is therefore dubbed RNA immunoprecipitation in tandem (RIPiT). https://www.jove.com/v/59913 566 2019-07-10T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/70090.jpg RNA-Associated Chromatin DNA-DNA Interaction Method Here, we present a protocol to capture RNA-associated chromatin DNA-DNA interactions for mapping RNA-related three-dimensional genome organization. https://www.jove.com/v/70090 661 2026-04-30T20:10:00+00:00 JoVE no https://visualize.jove.com/11496752-evaluation-of-systemic-activity-of-the-brain-by-means-of-an-artificial-intelligence-model monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3685.jpg A Fully Automated and Highly Versatile System for Testing Multi-cognitive Functions and Recording Neuronal Activities in Rodents In this report, we present a fully automated and highly versatile system capable of simultaneously testing multi-cognitive behaviors and recording neuronal activities for rodents. https://www.jove.com/v/3685 553 2012-05-03T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17752.jpg Brain Imaging Brain imaging technologies provide critical insights into both the structure and function of the human brain, enabling medical professionals and researchers to diagnose, study, and treat neurological disorders or psychiatric disorders more effectively. These technologies include computerized axial tomography (CAT or CT scans), positron-emission tomography (PET scans), magnetic resonance imaging (MRI), functional magnetic resonance imaging (fMRI), and Transcranial Magnetic Stimulation (TMS).<br... https://www.jove.com/v/17752 74 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53639.jpg Assessment and Communication for People with Disorders of Consciousness With this experiment, one might be able to detect consciousness in people with disorders of consciousness. Furthermore, the approach can create a simple communication channel that enables people to give simple YES/NO answers to questions. https://www.jove.com/v/53639 457 2017-08-01T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67871.jpg Evaluating Tests of Cognition using a Computerized Touch-Sensitive Tablet, Eye Tracking, and Functional Magnetic Resonance Imaging A protocol for simultaneous recording of visuomotor behavior and brain activity during standard paper-based cognitive tests using an MRI-compatible tablet and eye-tracking technology alongside functional MRI, towards improving the usage of such tests. Preliminary results are presented from a young healthy adult performing a Trail-Making test. https://www.jove.com/v/67871 610 2026-01-30T21:00:00+00:00 JoVE no https://visualize.jove.com/11523032-the-effect-of-host-factors-and-capsule-composition-on-the-cellular-overgrowth-on-implanted-alginate-capsules monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3388.jpg Generation of Alginate Microspheres for Biomedical Applications In the following sections, we outline procedures for the preparation of alginate microspheres for use in biomedical applications. We specifically illustrate a technique for creating multilayered alginate microspheres for the dual purpose of cell and protein encapsulation as a potential treatment for type 1 diabetes. https://www.jove.com/v/3388 633 2012-08-12T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52835.jpg Alginate Encapsulation of Pluripotent Stem Cells Using a Co-axial Nozzle We established a method of encapsulating pluripotent stem cells (PS cells) into alginate hydrogel capsules using a co-axial nozzle. This prevents cells from aggregating excessively and limits the shear stress experienced by cells in suspension culture. The technique is applicable to the mass production of PS cells as well as research on stem cell niche. https://www.jove.com/v/52835 433 2015-07-02T17:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53704.jpg Synthesis of Thermogelling Poly(N-isopropylacrylamide)-graft-chondroitin Sulfate Composites with Alginate Microparticles for Tissue Engineering An injectable tissue engineering scaffold composed of poly(N-isopropylacrylamide)-graft-chondroitin sulfate (PNIPAAm-g-CS)-containing alginate microparticles was prepared. The adhesive strength, swelling properties and in vitro biocompatibility are analyzed in this study. The characterization techniques developed here may be applicable to other thermogelling systems. https://www.jove.com/v/53704 742 2016-10-26T19:30:00+00:00 JoVE no https://visualize.jove.com/11523732-detection-of-alpha-electro-encephalogram-onset-following-eye-closure-using-four-location-based-techniques monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/50131.jpg Applications of EEG Neuroimaging Data: Event-related Potentials, Spectral Power, and Multiscale Entropy Neuroimaging researchers typically consider the brain's response as the mean activity across repeated experimental trials and disregard signal variability over time as "noise". However, it is becoming clear that there is signal in that noise. This article describes the novel method of multiscale entropy for quantifying brain signal variability in the time domain. https://www.jove.com/v/50131 675 2013-06-27T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54746.jpg Network Analysis of Foramen Ovale Electrode Recordings in Drug-resistant Temporal Lobe Epilepsy Patients This protocol describes a procedure to track the evolution of mesial network measures in temporal lobe epilepsy (TLE) patients. It is based on the combination of intracranial recordings with a novel numerical technique for data analysis. Specifically, we present a protocol for network analyses of foramen ovale recordings. https://www.jove.com/v/54746 572 2016-12-18T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57321.jpg Using Electroencephalography Measurements and High-quality Video Recording for Analyzing Visual Perception of Media Content We present detection, acquisition, and analysis of eyeblink rates while watching media content. https://www.jove.com/v/57321 641 2018-05-26T21:00:00+00:00 JoVE no https://visualize.jove.com/11533644-a-high-throughput-alphavirus-based-expression-cloning-system-for-mammalian-cells monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/52235.jpg Generation of Plasmid Vectors Expressing FLAG-tagged Proteins Under the Regulation of Human Elongation Factor-1α Promoter Using Gibson Assembly Synthesis of custom plasmids is labor and time consuming. This protocol describes the use of Gibson assembly cloning to reduce the work and duration of custom DNA cloning procedure. The protocol described also produces reliable tagged protein constructs for mammalian expression at similar cost to the traditional cut-and-paste DNA cloning. https://www.jove.com/v/52235 618 2015-02-09T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53568.jpg High Yield Expression of Recombinant Human Proteins with the Transient Transfection of HEK293 Cells in Suspension Laboratory-scale production of eukaryotic proteins with appropriate post-translational modification represents a significant barrier. Here is a robust protocol with rapid establishment and turnaround for protein expression using a mammalian expression system. This system supports selective amino acid, selective labeling of proteins and small molecule modulators of glycan composition. https://www.jove.com/v/53568 702 2015-12-28T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66320.jpg A Seamless Cloning Approach for Porcine Reproductive and Respiratory Syndrome Virus Expression Vector Construction Here, we present a protocol to obtain the pVAX1-PRRSV expression vector by introducing suitable restriction sites at the 3' end of the inserts. We can linearize the vector and join DNA fragments to the vector one by one through homologous recombination technology. https://www.jove.com/v/66320 258 2024-05-17T21:15:00+00:00 JoVE no https://visualize.jove.com/11540196-neural-correction-of-neutral-networks-for-control-identification-and-diagnosis monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1677.jpg An Experimental Platform to Study the Closed-loop Performance of Brain-machine Interfaces We use a closed-loop fly-machine interface to investigate general principles in neuronal control. https://www.jove.com/v/1677 651 2011-03-10T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10835.jpg Neural Regulation Digestion begins with a cephalic phase that prepares the digestive system to receive food. When our brain processes visual or olfactory information about food, it triggers impulses in the cranial nerves innervating the salivary glands and stomach to prepare for food. The cephalic phase is a conditioned or learned response to familiar foods. Our appetite or desire for a particular food modifies the preparatory responses directed by the brain. Individuals may produce more saliva and stomach... https://www.jove.com/v/10835 97 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52341.jpg Closed-loop Neuro-robotic Experiments to Test Computational Properties of Neuronal Networks In this paper, an experimental framework to perform closed-loop experiments is presented, in which information processing (i.e., coding and decoding) and learning of neuronal assemblies are studied during the continuous interaction with a robotic body. https://www.jove.com/v/52341 678 2015-03-02T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68588.jpg Soft Pneumatic Robot Modulates Graph Theory Metrics of Brain Network for Hand Rehabilitation After Stroke This study explores the effects of a configurable soft pneumatic robot on enhancing whole-brain network topology post-stroke. Graph theory analysis indicates significant improvements in clustering coefficient, path length, and global efficiency. Findings highlight the potential of programmable robotic protocols to modulate neuroplasticity and optimize functional recovery in stroke rehabilitation. https://www.jove.com/v/68588 330 2025-10-10T21:40:00+00:00 JoVE no https://visualize.jove.com/11540946-automation-bias-decision-making-and-performance-in-high-tech-cockpits monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11043.jpg Reason and Intuition The human brain processes information for decision-making using one of two routes: an intuitive system and a rational system (Epstein, 1994; popularized by Kahneman, 2011 as System 1 and System 2, respectively). The intuitive system is quick, impulsive, and operates with minimal effort, relying on emotions or habits to provide cues for what to do next, while the rational system is logical, analytical, deliberate, and methodical. Research in neuropsychology suggests that the brain can only use... https://www.jove.com/v/11043 97 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11048.jpg The Anchoring-and-Adjustment Heuristic In order to make good decisions, we use our knowledge and our reasoning. Often, this knowledge and reasoning is sound and solid. However, sometimes, we are swayed by biases or by others manipulating a situation. For example, let’s say you and three friends wanted to rent a house and had a combined target budget of $1,600. The realtor shows you only very run-down houses for $1,600 and then shows you a very nice house for $2,000. Might you ask each person to pay more in rent to get the $2,000... https://www.jove.com/v/11048 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18155.jpg Decision Making Decision-making is a fundamental cognitive process that involves evaluating alternatives and selecting among them. This process can range from simple choices, such as deciding what to wear, to complex decisions, like choosing a major in college or a career path. The complexity of the decision often dictates the approach we use, which can be broadly categorized into two types: automatic and controlled decision-making. Automatic decision-making is fast, intuitive, and relies on gut feelings... https://www.jove.com/v/18155 80 JoVE no https://cloudfront.jove.com/files/ftp_upload/19888/19888_article_thumb_19888.jpg Unrealistic Optimism Bias Unrealistic optimism bias is the tendency to overestimate the likelihood of positive outcomes. This cognitive bias makes individuals believe they are less likely to experience failures, setbacks, or risks and more likely to succeed than others. For example, people may assume they are less prone to health issues, accidents, or financial struggles than their peers, even when they share similar risk factors.One key component of this bias is the above-average effect, where individuals perceive... https://www.jove.com/v/19888 90 2025-09-18T16:24:21+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19940/19940_article_thumb_19940.jpg Motivational Bias Cognitive bias results from limitations in thinking and information processing, leading to systematic errors in judgment. Conversely, motivational bias stems from personal desires or emotions, causing distortions in perception to align with self-interest. Motivational bias influences how individuals perceive and attribute causes to events, often shaped by personal needs, goals, and self-esteem preservation. This bias can distort judgment, leading to inaccurate assessments of success, failure,... https://www.jove.com/v/19940 85 2025-09-18T16:24:02+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19941/19941_article_thumb_19941.jpg Halo Effect The halo effect is a cognitive bias in which an individual's overall impression influences judgments about their specific traits. This psychological phenomenon leads people to associate positive characteristics with those they perceive as generally good and negative characteristics with those they view as bad. This effect is particularly influential in social perception, professional evaluations, and decision-making processes.The Psychological Basis of the Halo EffectThe halo effect is rooted... https://www.jove.com/v/19941 87 2025-09-18T16:24:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65170.jpg Evaluating Flight Performance and Eye Movement Patterns Using Virtual Reality Flight Simulator A new virtual reality flight simulator was built, which enables efficient and low-cost evaluation of flight performance and eye movement patterns. It also provides a high-potential research tool for ergonomics and other research. https://www.jove.com/v/65170 229 2023-05-19T19:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66886.jpg Eye Tracking During A Complex Aviation Task For Insights Into Information Processing Eye tracking is a non-invasive method to probe information processing. This article describes how eye tracking can be used to study gaze behavior during a flight simulation emergency task in low-time pilots (i.e., <350 flight hours). https://www.jove.com/v/66886 468 2025-04-04T18:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68824.jpg High-definition Transcranial Direct Current Stimulation over Right Dorsolateral Prefrontal Cortex to Enhance Metacognitive Sensitivity This study proposed an experimental paradigm that applies High-Definition Transcranial Direct Current Stimulation (HD-tDCS) to improve human metacognition in human-AI delegation tasks. The results demonstrated the effectiveness of HD-tDCS in enhancing metacognitive sensitivity. https://www.jove.com/v/68824 371 2025-09-26T19:40:00+00:00 JoVE no https://visualize.jove.com/11541654-bioinstrumentation-for-evaluation-of-workload-in-payload-specialists-results-of-assess-ii monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/57590.jpg Evaluation of Commercial-Off-The-Shelf Wrist Wearables to Estimate Stress on Students A protocol to evaluate solutions based on commercial-off-the-shelf (COTS) wrist wearables to estimate stress in students is proposed. The protocol is carried out in two phases, an initial laboratory-based stress induction test, and a monitoring stage taking place in the classroom while the student is performing academic activities. https://www.jove.com/v/57590 771 2018-06-16T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59851.jpg Collecting Sleep, Circadian, Fatigue, and Performance Data in Complex Operational Environments Sleep loss and circadian misalignment contribute to numerous operational accidents and incidents. The effectiveness of countermeasures and work scheduling designs aimed at mitigating fatigue can be challenging to evaluate in operational environments. This manuscript summarizes an approach for collecting sleep, circadian, fatigue, and performance data in complex operational environments. https://www.jove.com/v/59851 516 2019-08-08T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/69621.jpg Estimate the Cognitive Load Using Electrocardiographic Measure: A Human-AI Collaborative Task This protocol describes the use of physiological indicators to measure variations in cognitive load across different task difficulty levels in human-AI collaborative tasks. The findings suggest that people adapt their decision-making processes according to task difficulty, thereby reflecting different levels of cognitive load. https://www.jove.com/v/69621 428 2025-12-05T22:45:00+00:00 JoVE no https://visualize.jove.com/11558607-solid-state-conformation-of-a-hybrid-tripeptide-between-beta-amino-acid-8-aminocyclooct-4-enecarboxylic-acid-and-2-aminoisobutyric-acid monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3373.jpg Solid-phase Submonomer Synthesis of Peptoid Polymers and their Self-Assembly into Highly-Ordered Nanosheets A simple and general manual peptoid synthesis method involving basic equipment and commercially available reagents is outlined, enabling peptoids to be easily synthesized in most laboratories. The synthesis, purification and characterization of an amphiphilic peptoid 36mer is described, as well as its self-assembly into highly-ordered nanosheets. https://www.jove.com/v/3373 822 2011-11-02T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10678.jpg Protein Organization Overview Proteins are one of the fundamental building blocks of life that carry out many diverse functions in the cell. Proteins are assembled from amino acids. The sequence of amino acids is known as the primary structure of a protein. Local interactions of individual amino acids cause the linear chain to fold into the secondary structures. Interactions of distant amino acids lead to further folding of the protein—the tertiary structure. The assembly of multiple folded chains (subunits) is... https://www.jove.com/v/10678 73 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11470.jpg Amino acids Amino acids are the monomers that comprise proteins. Each amino acid has the same fundamental structure, which consists of a central carbon atom, or the alpha (α) carbon, bonded to an amino group (NH2), a carboxyl group (COOH), and to a hydrogen atom. Every amino acid also has another atom or group of atoms bonded to the central atom known as the R group. There are 20 common amino acids present in proteins, each with a different R group. Variation in the amino acid sequence is responsible for... https://www.jove.com/v/11470 222 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11471.jpg Peptide Bonds A peptide bond covalently attaches amino acids through a dehydration reaction. One amino acid's carboxyl group and another amino acid's amino group combine, releasing a water molecule. The resulting bond is the peptide bond. The products that such linkages form are peptides. As more amino acids join this growing chain, the resulting chain is a polypeptide. Each polypeptide has a free amino group at one end. This end has the N-terminal, or the amino-terminal, and the other end has a free... https://www.jove.com/v/11471 163 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12356.jpg Structures of Carboxylic Acid Derivatives Structure of Carboxylic Acid Derivatives Carboxylic acid derivatives contain an acyl group attached to a heteroatom such as chlorine, oxygen, or nitrogen. The carbonyl carbon and oxygen are both sp2-hybridized with an unhybridized p orbital. The three sp2 orbitals of the carbonyl carbon form three σ bonds, one each with the carbonyl oxygen, the α carbon, and the heteroatom, whereas the other two sp2 orbitals of the carbonyl oxygen are occupied by the lone pairs. Further, the unhybridized p... https://www.jove.com/v/12356 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12487.jpg Protein Organization Proteins are polymers of amino acid residues. They are versatile and responsible for different cellular functions, including DNA replication, molecular transport, catalysis, and structural support. Proteins have a hierarchical structure comprising at least three levels of organization: primary, secondary, and tertiary structure. Some large proteins have a quaternary structure where individual protein subunits are linked together. The primary structure of a protein is its amino acid sequence. https://www.jove.com/v/12487 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12525.jpg Structure of Amines The hybridized nitrogen atom in amines possesses a lone pair of electrons and is bound to three substituents with a bond angle of around 108°, which is less than the tetrahedral angle of 109.5°. However, the C–N–H bond angle is slightly larger at 112°, with a carbon–nitrogen bond length of 147 pm. This carbon–nitrogen bond length of of amines is longer than the carbon–oxygen bond of alcohols (143 pm) but shorter than alkanes’ carbon–carbon bond (154 pm). These aspects are illustrated in Figure... https://www.jove.com/v/12525 79 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56652.jpg Synthesis and Mass Spectrometry Analysis of Oligo-peptoids A protocol is described for the manual synthesis of oligo-peptoids followed by sequence analysis by mass spectrometry. https://www.jove.com/v/56652 704 2018-02-21T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58368.jpg Synthesis and Structure Determination of µ-Conotoxin PIIIA Isomers with Different Disulfide Connectivities Cysteine-rich peptides fold into distinct three-dimensional structures depending on their disulfide connectivity. Targeted synthesis of individual disulfide isomers is required when buffer oxidation does not lead to the desired disulfide connectivity. The protocol deals with the selective synthesis of 3-disulfide-bonded peptides and their structural analysis using NMR and MS/MS studies. https://www.jove.com/v/58368 704 2018-10-02T21:00:00+00:00 JoVE no https://visualize.jove.com/11569160-computer-assisted-surgery-developments-and-prospects-in-2001-results-of-a-workshop-at-schloss-reisenburg-23-24-november-2000 monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/64796.jpg A Teleoperated Robotic System-Assisted Percutaneous Transiliac-Transsacral Screw Fixation Technique Teleoperated robotic system-assisted percutaneous transiliac-transsacral screw fixation is a feasible technique. Screw channels can be implemented with high accuracy owing to the excellent freedom of movement and stability of the robotic arms. https://www.jove.com/v/64796 357 2023-01-06T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66227.jpg Pioneering Patient-Specific Approaches for Precision Surgery Using Imaging and Virtual Reality Advancements in endovascular treatment have replaced complex open surgical procedures with minimally invasive options, like valve replacement and aneurysm repair. This paper proposes using three-dimensional (3D) modeling and virtual reality to aid in C-arm positioning, angle measurements, and roadmap generation for neuro-interventional catheterization lab procedural planning, minimizing procedure time. https://www.jove.com/v/66227 378 2024-04-05T20:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68607.jpg Technical Approach for Infrared Tracking for Soft Tissue Navigation with a Holographic Head-Mounted Display and Preclinical Validation This protocol offers a guide to implement infrared marker tracking for free-moving phantoms (e.g., organs) and holographic visualization using Augmented Reality. Additionally, it outlines a setup for preclinical validation of holographic navigation systems using electromagnetic tracking on free-moving phantoms. https://www.jove.com/v/68607 625 2025-09-02T21:15:00+00:00 JoVE no https://visualize.jove.com/11590018-intramers-as-promising-new-tools-in-functional-proteomics monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11511.jpg Protein-protein Interfaces Many proteins form complexes to carry out their functions, making protein-protein interactions (PPIs) essential for an organism's survival. Most PPIs are stabilized by numerous weak noncovalent chemical forces. The physical shape of the interfaces determines the way two proteins interact. Many globular proteins have closely-matching shapes on their surfaces, which form a large number of weak bonds. Additionally, many PPIs occur between two helices or between a surface cleft and a polypeptide... https://www.jove.com/v/11511 124 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11525.jpg Protein Networks An organism can have thousands of different proteins, and these proteins must cooperate to ensure the health of an organism. Proteins bind to other proteins and form complexes to carry out their functions. Many proteins interact with multiple other proteins creating a complex network of protein interactions. These interactions can be represented through maps depicting protein-protein interaction networks, represented as nodes and edges. Nodes are circles that are representative of a protein,... https://www.jove.com/v/11525 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13378.jpg Tagging and Fusion Proteins Proteins are involved in several cellular processes and biochemical reactions. Analyzing a specific protein of interest requires it to be isolated from the other proteins in the cell. This is achieved by overexpressing the specific gene in a suitable host to produce large quantities of the target protein. A tag or label is recombined with the gene to produce a fusion protein containing the target protein and the tag. The tags on these fusion proteins can then be used for easy detection and... https://www.jove.com/v/13378 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13388.jpg Proteomics A proteome is the entire set of proteins that a cell type produces. We can study proteomes using the knowledge of genomes because genes code for mRNAs, and the mRNAs encode proteins. Although mRNA analysis is a step in the right direction, not all mRNAs are translated into proteins. Proteomics is the study of proteomes' function. It involves the large-scale systematic study of the proteome to denote the protein complement expressed by a genome. Scientist Mark Wilkins coined the term proteomics... https://www.jove.com/v/13388 93 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59589.jpg Mass Spectrometry-Based Proteomics Analyses Using the OpenProt Database to Unveil Novel Proteins Translated from Non-Canonical Open Reading Frames OpenProt is a freely accessible database that enforces a polycistronic model of eukaryotic genomes. Here, we present a protocol for the use of OpenProt databases when interrogating mass spectrometry datasets. Using OpenProt database for analysis of proteomic experiments allows for discovery of novel and previously undetectable proteins. https://www.jove.com/v/59589 458 2019-04-11T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68707.jpg Navigating the Mass Spectrometry-Based Proteomic Data Using Free Computational Tools Mass spectrometry-based proteomic data is available in open databases and accessible using free tools. Given the complexity of database searches and descriptions, many biologists lack the knowledge to utilize these datasets. Here, we provide a guide on using free tools for basic proteomic data searches. https://www.jove.com/v/68707 421 2025-08-19T21:40:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/69197.jpg Mapping Dysfunctional Protein-Protein Interactions in Disease Here, we present a protocol to enable the capture and identification of disease-specific protein-protein interactions from native cells and tissues using chemical probes and mass spectrometry. The resulting interaction datasets are analyzed through a dedicated web-based platform to reveal dynamic network dysfunctions and pathway alterations linked to disease. https://www.jove.com/v/69197 579 2025-10-24T20:55:00+00:00 JoVE no https://visualize.jove.com/11698948-limited-role-for-ivus-in-the-endovascular-repair-of-aortoiliac-aneurysms monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15293.jpg Anastomoses In human anatomy, anastomosis refers to a connection or opening between two things, particularly between blood vessels or other tubular structures. The term is derived from the Greek term 'anastomosis,' which means 'outlet' or 'opening.' This natural network of connections plays a critical role in the survival and functionality of the human body. Anastomoses can be formed at arterial, venous, and lymphatic vessels. Arterial Anastomosis: These occur between arteries. They are most common in... https://www.jove.com/v/15293 79 JoVE no https://cloudfront.jove.com/files/ftp_upload/17981/17981_article_thumb_17981.jpg Aneurysm III: Interprofessional Care Aneurysm management involves either conservative medical therapy or surgical intervention, depending on the size and symptoms of the aneurysm. Conservative management is generally reserved for smaller, asymptomatic aneurysms, while larger or symptomatic aneurysms often necessitate surgical repair.Conservative Medical TherapyFor small, asymptomatic aneurysms, particularly abdominal aortic aneurysms (AAA) less than 5.5 centimeters in diameter, conservative medical therapy is recommended. This... https://www.jove.com/v/17981 86 2025-06-19T16:19:25+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17982/17982_article_thumb_17982.jpg Aneurysm IV: Nursing Management Vigilant monitoring for aneurysm rupture is essential for patients undergoing aortic surgery.Preoperative Nursing ManagementContinuously monitor the patient for manifestations of aneurysm rupture, such as pallor, weakness, tachycardia, hypotension, abdominal, back, groin, or periumbilical pain, changes in consciousness, and a pulsating abdominal mass. Regularly assess the patient's peripheral pulses.Instruct the patient to consume a clear liquid diet the day before surgery and administer... https://www.jove.com/v/17982 82 2025-06-19T16:19:35+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50740.jpg A New Murine Model of Endovascular Aortic Aneurysm Repair Histological and biochemical modifications after aneurysm endograft exclusion are still unclear. We describe a new model of endograft implantation on a murine aneurysm. Through thrombus analysis with and without persistant circulating blood stream interface, and new endovascular biomaterials evaluation, this model will help to better understand endovascular aneurysm exclusion pathobiology. https://www.jove.com/v/50740 531 2013-07-07T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63738.jpg Microsurgical Creation of Giant Bifurcation Aneurysms in Rabbits for the Evaluation of Endovascular Devices Here, we describe the technique for the microsurgical creation of giant bifurcation aneurysms in rabbits for the evaluation of endovascular devices. https://www.jove.com/v/63738 441 2023-09-08T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64956.jpg Reduction of Radiation Exposure during Endovascular Treatment of Peripheral Arterial Disease Combining Fiber Optic RealShape Technology and Intravascular Ultrasound Described here is a stepwise method of combining Fiber Optic RealShape technology and intravascular ultrasound to show the potential of merging both techniques, in view of the reduction of radiation exposure and improvement of navigation tasks and treatment success during an endovascular procedure for the treatment of peripheral arterial disease. https://www.jove.com/v/64956 828 2023-04-21T19:10:00+00:00 JoVE no https://visualize.jove.com/11712321-polymorphism-of-genes-coding-for-angiotensin-i-converting-enzyme-and-methylenetetrahydrofolate-reductase-in-patients-with-ischemic-heart-disease monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15023.jpg Antihypertensive Drugs: Angiotensin-Converting Enzyme Inhibitors Angiotensin-converting enzyme (ACE), a vital component of the renin-angiotensin-aldosterone system, is abundant in lung endothelial cells. ACE converts the inactive decapeptide, angiotensin I, into the active octapeptide, angiotensin II. This potent vasoconstrictor narrows blood vessels, increasing resistance to blood flow and elevating blood pressure. Angiotensin II also stimulates aldosterone production, encouraging kidney cells to reabsorb more sodium and water from urine, thereby increasing... https://www.jove.com/v/15023 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15037.jpg Heart Failure Drugs: Inhibitors of Renin-Angiotensin System The activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) contributes to cardiac remodeling, and inhibiting the RAAS is a pharmacological target in heart failure management. As a result, neurohumoral modulation is a crucial treatment principle for managing heart failure. This approach involves using medications like ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), β-blockers, mineralocorticoid receptor antagonists (MRAs), and neutral... https://www.jove.com/v/15037 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/17221/17221_article_thumb_17221.jpg Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu Genetic variations significantly influence drug response through pharmacokinetics, receptor interactions, and biologic milieu modifications. Pharmacokinetic alterations impact drug metabolism and clearance, affecting efficacy and toxicity. Variants in drug-metabolizing enzymes, such as CYP2C9 and CYP2C19, alter drug activation and elimination. For example, CYP2C9 loss-of-function variants require lower warfarin doses to prevent excessive bleeding, while CYP2C19 variants reduce clopidogrel... https://www.jove.com/v/17221 89 2026-02-12T19:17:23+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17223/17223_article_thumb_17223.jpg Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes Cytochrome P450 (CYP450) enzymes are a superfamily of heme-containing monooxygenases that play a pivotal role in Phase I drug metabolism by catalyzing oxidation and reduction reactions.These enzymes transform lipophilic xenobiotics into more hydrophilic metabolites, facilitating subsequent Phase II conjugation and eventual excretion. The CYP450 family is classified into families (e.g., CYP1–CYP3) and subfamilies (e.g., CYP2A, CYP2C), based on amino acid sequence homology.CYP450 isoenzymes,... https://www.jove.com/v/17223 88 2026-02-12T19:17:22+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17226/17226_article_thumb_17226.jpg Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase Genetic polymorphisms in drug targets have emerged as critical determinants of interindividual variability in drug response and toxicity. Pharmacogenomic investigations increasingly focus on identifying these variations to personalize and optimize therapeutic interventions. A drug target may be a receptor, enzyme, or signaling protein involved in pharmacologic responses or disease-related pathways. While early pharmacogenetic studies focused primarily on drug metabolism, current research... https://www.jove.com/v/17226 71 2026-02-12T19:16:57+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17227/17227_article_thumb_17227.jpg Pharmacogenomics: Identification of New Drug Targets Advances in genomics have profoundly influenced drug discovery by increasing both the speed and accuracy of pharmaceutical development. Pharmacogenomics, which examines how genetic variation influences drug response, facilitates the identification of novel therapeutic targets and enables patient stratification for personalized treatment. These strategies contribute to improved drug efficacy, minimized adverse effects, and more efficient clinical trial design.Mapping genetic differences... https://www.jove.com/v/17227 89 2026-02-12T19:17:26+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57289.jpg A Method to Study the C924T Polymorphism of the Thromboxane A2 Receptor Gene In the present study, we describe a methodology to analyze the C924T genotype. The protocol consists of three phases: DNA extraction, amplification by polymerase chain reaction (PCR), and analysis of the restriction fragment length polymorphism (RFLP) on agarose gel. https://www.jove.com/v/57289 420 2019-04-01T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63949.jpg Investigating the Pathogenesis of MYH7 Mutation Gly823Glu in Familial Hypertrophic Cardiomyopathy using a Mouse Model Based on the familial hereditary cardiomyopathy family found in our clinical work, we created a C57BL/6N mouse model with a point mutation (G823E) at the mouse MYH7 locus through CRISPR/Cas9-mediated genome engineering to verify this mutation. https://www.jove.com/v/63949 225 2022-08-08T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66058.jpg Multi-Gene Single Nucleotide Polymorphism Detection in Gastric Cancer Based on Ion Semiconductor Sequencing Platform This protocol proposes holistic laboratory procedures required to detect single nucleotide polymorphisms in gastric cancer samples based on an ion semiconductor sequencing platform. The target sequences, ligating adapters, library amplification and purification, and quality control criteria are also described in detail. https://www.jove.com/v/66058 381 2024-05-10T20:30:00+00:00 JoVE no https://visualize.jove.com/11721807-digital-mammography-wavelet-transform-and-kalman-filtering-neural-network-in-mass-segmentation-and-detection monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/50341.jpg Detection of Architectural Distortion in Prior Mammograms via Analysis of Oriented Patterns We demonstrate methods for the detection of architectural distortion in prior mammograms. Oriented structures are analyzed using Gabor filters and phase portraits to detect sites of radiating tissue patterns. Each site is characterized and classified using measures to represent spiculating patterns. The methods should assist in the detection of breast cancer. https://www.jove.com/v/50341 824 2013-08-30T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64500.jpg Application of Deep Learning-Based Medical Image Segmentation via Orbital Computed Tomography An object segmentation protocol for orbital computed tomography (CT) images is introduced. The methods of labeling the ground truth of orbital structures by using super-resolution, extracting the volume of interest from CT images, and modeling multi-label segmentation using 2D sequential U-Net for orbital CT images are explained for supervised learning. https://www.jove.com/v/64500 288 2022-11-30T21:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/69252.jpg Automated Joint Space Detection Improves Bone Segmentation Accuracy The development of an automated joint space detection workflow enabled high-throughput segmentation of distinct murine hindpaw bones with >98% accuracy in wild-type animals. Flexible application to forepaws and paws with inflammatory-erosive arthritis was achieved, but with deprecated performance that warrants further optimization in future studies using publicly available data. https://www.jove.com/v/69252 405 2025-11-28T20:50:00+00:00 JoVE no https://visualize.jove.com/11722728-discovery-and-distribution-of-super-integrons-among-pseudomonads monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17218/17218_article_thumb_17218.jpg Extracorporeal Removal of Drugs: Continuous Renal Replacement Therapy Continuous Renal Replacement Therapy (CRRT) is an essential intervention for patients experiencing severe kidney dysfunction. This therapy offers a continuous mechanism for removing fluids and toxins from the bloodstream, leveraging the patient’s blood pressure to facilitate filtration through a specialized filter. This method contrasts with intermittent dialysis, providing a gentler and more consistent removal of waste products and excess fluid, which is particularly beneficial in critically... https://www.jove.com/v/17218 86 2025-10-03T14:00:16+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18479/18479_article_thumb_18479.jpg Continuous Renal Replacement Therapy Continuous Renal Replacement Therapy, also known as CRRT, is a procedural treatment for acute kidney injury (AKI) that gradually removes uremic toxins and fluids while maintaining acid-base balance and stabilizing electrolytes. It is particularly useful for hemodynamically unstable patients. Unlike intermittent hemodialysis, which is faster, CRRT provides a gentler approach over 24 hours, closely mimicking the function of natural kidneys. However, CRRT is not ideal for patients with... https://www.jove.com/v/18479 90 2025-06-19T16:27:33+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18483/18483_article_thumb_18483.jpg Kidney Transplant I: Introduction A kidney transplant is a surgical approach that involves replacing a non-functioning kidney with a healthy one from a donor. This procedure is often a treatment option for end-stage renal disease (ESRD) patients. The method requires careful recipient selection, including evaluating various medical and psychosocial factors. These criteria vary between transplant centers but generally include assessments of the patient's overall health, adherence to medical recommendations, and lifestyle... https://www.jove.com/v/18483 88 2025-08-11T16:58:32+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18501/18501_article_thumb_18501.jpg Acute Kidney Injury V: Interprofessional Care Acute Kidney Injury (AKI) requires a collaborative healthcare approach to restore renal function and prevent complications. Essential management strategies involve monitoring fluid and electrolyte balance, adjusting medications, initiating dialysis when necessary, and providing nutritional support.Fluid and Electrolyte ManagementFluid Monitoring: Regularly monitoring body weight, central venous pressure, and urine output helps detect fluid imbalances early. Patient intake and output are... https://www.jove.com/v/18501 80 2025-06-19T16:32:01+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18503/18503_article_thumb_18503.jpg Chronic Kidney Disease I: Introduction Chronic Kidney Disease (CKD) arises when the kidneys progressively lose their ability to function, ultimately leading to end-stage renal disease. At this advanced stage, the kidneys can no longer filter waste or maintain essential body functions, requiring renal replacement therapy (RRT) through dialysis or a kidney transplant for survival.Early-stage chronic kidney disease and detection challengesIn CKD's early stages, symptoms often remain absent because healthy nephrons compensate for... https://www.jove.com/v/18503 85 2025-08-11T16:57:32+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18505/18505_article_thumb_18505.jpg Chronic Kidney Disease III: Interprofessional Care Chronic kidney disease (CKD) requires collaborative and comprehensive management. CKD progresses through stages and can lead to end-stage kidney disease (ESKD) if untreated. Interprofessional collaboration and patient education are crucial, enabling patients to manage their health and improve their quality of life.Diagnostic approach for chronic kidney diseaseThe diagnosis of CKD primarily focuses on the glomerular filtration rate (GFR), which assesses kidney function by measuring how well... https://www.jove.com/v/18505 88 2025-06-19T16:32:48+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61899.jpg Digital Home-Monitoring of Patients after Kidney Transplantation: The MACCS Platform The MACCS platform is a comprehensive telemedicine concept aiming at better outcomes after kidney transplantation by sharing key medical information between patients and physicians. A telemedicine team reviews incoming data to detect potential complications and to improve adherence in kidney transplant recipients to achieve better long-term outcomes. https://www.jove.com/v/61899 433 2021-04-12T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62220.jpg Robot-Assisted Kidney Transplantation This paper provides technical details for robot-assisted kidney transplantation from a living donor. https://www.jove.com/v/62220 450 2021-07-19T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67322.jpg 5/6 Nephrectomy Using Sharp Bipolectomy Via Midline Laparotomy in Rats This manuscript introduces a standardized protocol for a 5/6 nephrectomy by sharp bipolectomy via midline laparotomy in a rat model, aiming to induce a state of renal insufficiency via renal parenchyma reduction with a great degree of methodical precision and low risk of technical error. https://www.jove.com/v/67322 334 2025-04-04T20:00:00+00:00 JoVE no https://visualize.jove.com/11736086-information-circulation-in-a-two-mode-solid-state-laser-with-optical-feedback monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16094.jpg Feedback control systems Feedback control systems are categorized in various ways based on their design, analysis, and signal types. Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity... https://www.jove.com/v/16094 86 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53679.jpg Automation of Mode Locking in a Nonlinear Polarization Rotation Fiber Laser through Output Polarization Measurements A protocol to detect and automate mode locking in a pre-adjusted nonlinear polarization rotation fiber laser is presented. The detection of a sudden change in the output polarization state when mode locking occurs is used to command the alignment of an intra-cavity polarization controller in order to find mode-locking conditions. https://www.jove.com/v/53679 858 2016-02-28T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53889.jpg Characterization of Anisotropic Leaky Mode Modulators for Holovideo This work describes fabrication and characterization of anisotropic leaky mode modulators for holographic video. https://www.jove.com/v/53889 576 2016-03-19T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60160.jpg Low-cost Custom Fabrication and Mode-locked Operation of an All-normal-dispersion Femtosecond Fiber Laser for Multiphoton Microscopy A method is presented to build a custom low-cost, mode-locked femtosecond fiber laser for potential applications in multiphoton microscopy, endoscopy, and photomedicine. This laser is built using commercially available parts and basic splicing techniques. https://www.jove.com/v/60160 528 2019-11-22T20:30:00+00:00 JoVE no https://visualize.jove.com/11753004-closed-loop-control-of-anesthesia-using-bispectral-index-performance-assessment-in-patients-undergoing-major-orthopedic-surgery-under-combined-general-and-regional-anesthesia monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14503.jpg Local Anesthetics: Clinical Application as Spinal Anesthesia Spinal anesthetics are given during lower abdomen and limb surgeries to block sensory and motor neurons. They are administered in the mid to low lumbar regions, primarily acting on the cauda equina's nerve roots. The blockade level depends on the local anesthetic (LA) concentration. Usually, low LA concentrations are sufficient to block sensory fibers, while only high LA concentrations block motor fibers. Other factors like injection volume and speed, the patient's posture, and the drug... https://www.jove.com/v/14503 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14749.jpg Local Anesthetics: Clinical Application as Intravenous Regional Anesthesia Intravenous regional anesthesia or the Bier block technique is used to anesthetize a specific limb or extremity. It uses exsanguinated or blood-drained vessels to transport local anesthetics or LAs to the peripheral nerve trunks. Lidocaine without vasoconstrictors like epinephrine is most commonly used for this technique. Other drugs used are prilocaine, ropivacaine, and chloroprocaine. Bupivacaine is not recommended for this technique due to its high cardiac toxicity. One of the advantages of... https://www.jove.com/v/14749 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15188.jpg General Anesthesia: Overview Anesthesia is a medical procedure that uses drugs for CNS suppression to enable painless surgeries and procedures. The selection of anesthetics is influenced by their pharmacokinetic properties, side effects, and patient characteristics. Various types of anesthesia include general, local, regional, spinal, and inhalational. General anesthesia induces unconsciousness in the whole body, while the others target specific areas or sensations. It is administered to minimize adverse effects, maintain... https://www.jove.com/v/15188 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15189.jpg Stages of General Anesthesia Various sedation levels offer significant advantages in facilitating procedural interventions for patients undergoing medical or invasive surgical procedures. These levels span from anxiolysis to general anesthesia, providing a spectrum of sedative effects to cater to specific patient needs. Anxiolysis reduces anxiety and is achieved through minimal sedation, enabling patients to remain awake and responsive while feeling more at ease during the procedure. This level can benefit minor... https://www.jove.com/v/15189 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15190.jpg Parenteral Anesthetics: Overview Intravenous anesthetics are drugs administered parenterally to induce anesthesia or sedation. Propofol is a widely used agent formulated as a 1% emulsion in soybean oil, glycerol, and egg phosphatide. It induces rapid anesthesia primarily due to its rapid distribution from the bloodstream to target tissues and is metabolized in the liver. However, it can cause significant pain on injection and hypertriglyceridemia. Fospropofol, a water-based prodrug of propofol, lacks these adverse effects. https://www.jove.com/v/15190 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15191.jpg Inhalational Anesthetics: Overview Inhalation anesthetics are drugs that induce general anesthesia upon inhalation. They work by increasing the sensitivity of GABAA receptors or inhibiting NMDA receptors, leading to a decrease in central nervous system activity. The depth of anesthesia can be rapidly adjusted by changing the concentration of the inhaled gas. Some common examples of inhalational anesthetics include volatile liquids like isoflurane, desflurane, sevoflurane and gases like xenon and nitrous oxide. Isoflurane, a... https://www.jove.com/v/15191 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54739.jpg Drug-Induced Sleep Endoscopy (DISE) with Target Controlled Infusion (TCI) and Bispectral Analysis in Obstructive Sleep Apnea The aim of this study was to establish a standardized protocol for sleep endoscopy to differentiate obstruction patterns in obstructive sleep apnea (OSA). Target-controlled infusion (TCI) of the sedative was combined with real-time monitoring of the depth of sedation using bispectral analysis. https://www.jove.com/v/54739 474 2016-12-06T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56881.jpg Recording Brain Electromagnetic Activity During the Administration of the Gaseous Anesthetic Agents Xenon and Nitrous Oxide in Healthy Volunteers Simultaneous magnetoencephalography and electroencephalography provides a useful tool to search for common and distinct macro-scale mechanisms of reductions in consciousness induced by different anesthetics. This paper illustrates the empirical methods underlying the recording of such data from healthy humans during N-Methyl-D-Aspartate-(NMDA)-receptor-antagonist-based anesthesia during inhalation of nitrous oxide and xenon. https://www.jove.com/v/56881 892 2018-01-13T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65235.jpg Non-Intubated Video-Assisted Thoracoscopic Surgery Here, we present a non-intubated protocol for performing video-assisted thoracoscopic surgery with preserved autonomic breathing. https://www.jove.com/v/65235 339 2023-05-26T19:10:00+00:00 JoVE no https://visualize.jove.com/11767220-an-expert-system-for-the-diagnosis-of-epilepsy-results-of-a-clinical-trial monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15214.jpg Epilepsy and Seizures: Overview Epilepsy is a chronic neurological disease marked by recurrent, unpredictable seizures. These seizures are caused by abnormal electrical discharges in the brain, leading to behavior, sensation, or consciousness alterations. They can also cause transient impairment of awareness, interfering with daily activities. Various factors can trigger epilepsy, including genetic factors, brain damage, metabolic causes, and unknown etiology. Diagnosis of epilepsy involves electroencephalography (EEG), which... https://www.jove.com/v/15214 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15215.jpg Seizures: Classification Epilepsy is primarily characterized by unpredictable seizures, either provoked by an identifiable factor, such as injury or illness, or unprovoked, occurring spontaneously without apparent cause. Seizures are typically classified into two main categories: focal and generalized seizures. Focal Seizures Focal seizures originate from specific regions of the brain. These seizures are further sub-classified into two types: Focal aware seizures: In these seizures, the person remains conscious... https://www.jove.com/v/15215 73 JoVE no https://cloudfront.jove.com/files/ftp_upload/40950/40950_article_thumb_40950.jpg Seizures l: Introduction Understanding seizures and epilepsy relies on key definitions that help in recognizing, classifying, and managing these disorders. These definitions provide a framework for recognizing, classifying, and managing seizure disorders.DefinitionsA seizure is a sudden, abnormal burst of electrical activity in the brain that can cause changes in awareness, movement, sensation, or behavior, depending on the area involved. Epilepsy is a chronic condition characterized by recurrent, unprovoked seizures,... https://www.jove.com/v/40950 80 2026-04-15T17:37:41+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40954/40954_article_thumb_40954.jpg Epilepsy ll: Types Recurrent seizures, stemming from abnormal electrical activity in the brain, are the defining characteristic of epilepsy, a chronic neurological condition. Because seizure features vary greatly, epilepsy is classified using two systems: by seizure type and by epilepsy syndromes. These classifications enable clinicians to describe seizure patterns and select suitable treatment strategies.I. Classification by Seizure Type1. Focal EpilepsyFocal epilepsy begins in one hemisphere of the brain. https://www.jove.com/v/40954 82 2026-04-13T23:55:56+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51947.jpg Performing Behavioral Tasks in Subjects with Intracranial Electrodes Patients implanted with intracranial electrodes provide a unique opportunity to record neurological data from multiple areas of the brain while the patient performs behavioral tasks. Here, we present a method of recording from implanted patients that can be reproducible at other institutions with access to this patient population. https://www.jove.com/v/51947 730 2014-10-02T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53206.jpg Stereo-Electro-Encephalo-Graphy (SEEG) With Robotic Assistance in the Presurgical Evaluation of Medical Refractory Epilepsy: A Technical Note Stereo-electroencephalography (SEEG) aids in localization of epileptogenic zones, however, remains relatively underutilized in the United States. The goal of this abstract is to provide a brief introduction to the technique of SEEG and further a detailed technique of using robotic assistance in the placement of SEEG electrodes. https://www.jove.com/v/53206 354 2016-06-13T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66494.jpg Electromagnetic Source Imaging in Presurgical Evaluation of Children with Drug-Resistant Epilepsy Magnetoencephalography (MEG) and high-density electroencephalography (HD-EEG) are rarely recorded simultaneously, although they yield confirmatory and complementary information. Here, we illustrate the experimental setup for recording simultaneous MEG and HD-EEG and the methodology for analyzing these data aiming to localize epileptogenic and eloquent brain areas in children with drug-resistant epilepsy. https://www.jove.com/v/66494 597 2024-09-20T19:50:00+00:00 JoVE no https://visualize.jove.com/11790276-use-of-artificial-neural-networks-in-prostate-cancer monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/67873.jpg A Cognitive Fusion-guided Prostate Biopsy Using Multiparametric Magnetic Resonance Imaging and Transrectal Ultrasound Prostate biopsy is the gold standard diagnostic method for prostate cancer. Cognitive fusion-guided prostate biopsy, which combines transrectal ultrasound with pre-measured MRI parameters, improves biopsy accuracy and enhances the detection rate of clinically significant prostate cancer. https://www.jove.com/v/67873 368 2025-03-21T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68083.jpg Detection and Isolation of Cancer in Prostate Biopsies Using Stimulated Raman Histology and Artificial Intelligence Here, we present a standardized protocol for detecting prostate cancer using stimulated Raman histology (SRH) on biopsy samples due to advantages over traditional histopathology, focusing on sample preparation, imaging, and artificial intelligence to improve the cancer-to-tissue ratio. Additionally, it supports biobanking for transcriptomics, organoid or xenograft models, and identification of intraoperative surgical margins. https://www.jove.com/v/68083 485 2025-06-10T19:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68270.jpg Introduction of an Integrated Pathology Image Management, Artificial Intelligence, and Reporting System Integrated image management, artificial intelligence (AI), and reporting systems have revolutionized diagnostic pathology practice. In this paper, we introduce FlexLIS, a state-of-the-art system that enables AI to assist pathologists in performing histopathology image assessments and generating diagnostic reports. https://www.jove.com/v/68270 333 2025-07-11T22:40:00+00:00 JoVE no https://visualize.jove.com/11801452-mechanism-and-control-of-class-switch-recombination monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2130.jpg Induction and Assessment of Class Switch Recombination in Purified Murine B Cells Following antigen exposure, subpopulations of activated B cells undergo a process known as class switch recombination (CSR) to produce antibody isotypes with distinct effector functions. The protocol outlined in this report explains how CSR can be induced and analyzed in vitro for the purposes of studying B cell function. https://www.jove.com/v/2130 589 2010-08-14T00:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10769.jpg Crossing Over Unlike mitosis, meiosis aims for genetic diversity in its creation of haploid gametes. Dividing germ cells first begin this process in prophase I, where each chromosome—replicated in S phase—is now composed of two sister chromatids (identical copies) joined centrally. The homologous pairs of sister chromosomes—one from the maternal and one from the paternal genome—then begin to align alongside each other lengthwise, matching corresponding DNA positions in a process called synapsis. In order to... https://www.jove.com/v/10769 94 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11569.jpg Gene Conversion Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new... https://www.jove.com/v/11569 128 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11575.jpg Conservative Site-specific Recombination and Phase Variation Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines. The recognition sites for Cre recombinase called LoxP... https://www.jove.com/v/11575 173 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11569.jpg Gene Conversion Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new... https://www.jove.com/v/13204 128 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13438.jpg Crossing Over Crossing over is the exchange of genetic information between homologous chromosomes during prophase I of meiosis I. Genetic recombination gives rise to allelic diversity in the newly formed daughter cells. In humans, crossing over produces genetically distinct haploid egg and sperm cells that undergo fertilization to produce unique offspring. Before cell division starts, the germ cell’s chromosome(s) undergo duplication in the S phase of the cell cycle. As the cells enter prophase I, duplicated... https://www.jove.com/v/13438 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15154.jpg Carrier Generation and Recombination Carrier generation is the process by which electron-hole pairs (EHPs) are created within the semiconductor. In direct-bandgap semiconductors, such as gallium arsenide (GaAs), this occurs efficiently when energy absorption prompts valence electrons to leap into the conduction band, leaving behind holes. This process is given by the generation rate G and is efficient due to the conservation of momentum between the valence band maximum and conduction band minimum. Indirect generation involves an... https://www.jove.com/v/15154 82 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52155.jpg Subcloning Plus Insertion (SPI) - A Novel Recombineering Method for the Rapid Construction of Gene Targeting Vectors Gene targeting methodologies can be used to generate transgenic mice with knockout, knock-in and tagged alleles. Here, we describe an improved method of recombineering in E. coli, that we term ‘subcloning plus insertion’, which can be used to generate custom gene targeting vectors rapidly. https://www.jove.com/v/52155 542 2015-01-08T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61551.jpg Analysis of Somatic Hypermutation in the JH4 intron of Germinal Center B cells from Mouse Peyer's Patches Presented here is an assay to quantify somatic hypermutation within the immunoglobulin heavy chain gene locus using germinal center B cells from mouse Peyer’s patches. https://www.jove.com/v/61551 575 2021-04-20T20:00:00+00:00 JoVE no https://visualize.jove.com/11809876-a-critical-epitope-for-substrate-recognition-by-the-nucleosome-remodeling-atpase-iswi monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11532.jpg The Nucleosome Core Particle Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins. The paradox Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA... https://www.jove.com/v/11532 130 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11533.jpg Nucleosome Remodeling Nucleosomes are the basic units of chromatin compaction. Each nucleosome consists of the DNA bound tightly around a histone core, which makes the DNA inaccessible to DNA binding proteins such as DNA polymerase and RNA polymerase. Hence, the fundamental problem is to ensure access to DNA when appropriate, despite the compact and protective chromatin structure. Nucleosome remodeling complex Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes... https://www.jove.com/v/11533 174 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12223.jpg Single-Strand DNA Binding Proteins For successful DNA replication, the unwinding of double-stranded DNA must be accompanied by stabilization and protection of the separated single strands of the DNA. This crucial task is performed by single-strand DNA-binding (SSB) proteins. They bind to the DNA in a sequence-independent manner, which means that the nitrogenous bases of the DNA need not be present in a specific order for binding of SSB proteins to it. The binding of SSB proteins straightens single-stranded DNA (ssDNA) and makes... https://www.jove.com/v/12223 63 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11531.jpg The Nucleosome DNA in a human cell is almost 2m long and it is packed inside a tiny nucleus that is only a few microns in diameter. The level of compaction of DNA inside the nucleus is astonishing. It is organized into several sequentially higher levels of compaction to fit into such a tiny space. The most compact form of DNA is a chromosome that can be seen under a microscope in a dividing cell. DNA is wound twice around a protein complex called histone core, that consist of 8 histone proteins. This complex... https://www.jove.com/v/13183 153 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13914.jpg The Nucleosome Human DNA is almost two meters long. However, it is compressed inside a tiny nucleus measuring only a few microns in diameter. To make this degree of compaction possible, DNA is organized into several sequential levels so that it can fit into such a tiny space. The most compact form of DNA is a chromosome that can be seen under a microscope in a dividing cell. In a chromosome, DNA is wound twice around a protein complex called a histone octamer core, which consists of 8 histone proteins. This... https://www.jove.com/v/13914 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14746.jpg The Nucleosome Core Particle Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins. Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during... https://www.jove.com/v/14746 72 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51721.jpg Biochemical Assays for Analyzing Activities of ATP-dependent Chromatin Remodeling Enzymes Here we describe biochemical assays that can be used to characterize ATP-dependent chromatin remodeling enzymes for their abilities to 1) catalyze ATP-dependent nucleosome sliding, 2) engage with nucleosome substrates, and 3) hydrolyze ATP in a nucleosome- or DNA-dependent manner. https://www.jove.com/v/51721 614 2014-10-25T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58820.jpg Probing The Structure And Dynamics Of Nucleosomes Using Atomic Force Microscopy Imaging Here, we present a protocol to characterize nucleosome particles at the single-molecule level using static and time-lapse atomic force microscopy (AFM) imaging techniques. The surface functionalization method described allows for the capture of the structure and dynamics of nucleosomes in high-resolution at the nanoscale. https://www.jove.com/v/58820 592 2019-01-31T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63147.jpg CD Spectroscopy to Study DNA-Protein Interactions The interaction of an ATP-dependent chromatin remodeler with a DNA ligand is described using CD spectroscopy. The induced conformational changes on a gene promoter analyzed by the peaks generated can be used to understand the mechanism of transcriptional regulation. https://www.jove.com/v/63147 408 2022-02-10T22:00:00+00:00 JoVE no https://visualize.jove.com/11825419-endovascular-treatment-of-intracranial-aneurysms-with-gdc-report-of-8-cases monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17979/17979_article_thumb_17979.jpg Aneurysm I: Introduction An aortic aneurysm is a localized outpouching or dilation at a weak point in the artery wall. It may involve different parts of the aorta, such as the abdominal aorta, aortic arch, or thoracic aorta.Etiological factorsSeveral disorders are associated with aortic aneurysms.Congenital causes, such as primary connective tissue disorders like Marfan syndrome, impact the integrity and strength of connective tissues, notably affecting the aorta. Marfan syndrome is a genetic disorder that specifically... https://www.jove.com/v/17979 90 2025-06-19T16:19:01+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17980/17980_article_thumb_17980.jpg Aneurysm II: Clinical Manifestations and Diagnostic Studies Thoracic, aortic arch and abdominal aneurysms are significant vascular conditions that can present with various clinical manifestations and lead to serious complications. Understanding these manifestations and the appropriate diagnostic studies is essential for effective management and treatment.Thoracic Aortic AneurysmsThoracic aortic aneurysms often remain asymptomatic until they reach a size that impinges on adjacent structures. They typically cause deep, diffuse chest pain that radiates to... https://www.jove.com/v/17980 81 2025-06-19T16:19:14+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17981/17981_article_thumb_17981.jpg Aneurysm III: Interprofessional Care Aneurysm management involves either conservative medical therapy or surgical intervention, depending on the size and symptoms of the aneurysm. Conservative management is generally reserved for smaller, asymptomatic aneurysms, while larger or symptomatic aneurysms often necessitate surgical repair.Conservative Medical TherapyFor small, asymptomatic aneurysms, particularly abdominal aortic aneurysms (AAA) less than 5.5 centimeters in diameter, conservative medical therapy is recommended. This... https://www.jove.com/v/17981 86 2025-06-19T16:19:25+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17982/17982_article_thumb_17982.jpg Aneurysm IV: Nursing Management Vigilant monitoring for aneurysm rupture is essential for patients undergoing aortic surgery.Preoperative Nursing ManagementContinuously monitor the patient for manifestations of aneurysm rupture, such as pallor, weakness, tachycardia, hypotension, abdominal, back, groin, or periumbilical pain, changes in consciousness, and a pulsating abdominal mass. Regularly assess the patient's peripheral pulses.Instruct the patient to consume a clear liquid diet the day before surgery and administer... https://www.jove.com/v/17982 82 2025-06-19T16:19:35+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51661.jpg Minimally Invasive Thumb-sized Pterional Craniotomy for Surgical Clip Ligation of Unruptured Anterior Circulation Aneurysms Minimally invasive thumb-sized pterional craniotomy for aneurysm clipping has afforded our patients with a shorter hospital stay at a lower cost compared to the national average. https://www.jove.com/v/51661 718 2015-08-11T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55522.jpg Comprehensive Endovascular and Open Surgical Management of Cerebral Arteriovenous Malformations Surgery is the gold standard for accessible arteriovenious malformations (AVMs), and pre-operative embolization can simplify this procedure. We describe our approach for staged endovascular embolization and open resection of AVMs, and provide a representative clinical example highlighting the advantages of a comprehensively trained neurovascular surgeon leading a multi-disciplinary clinical team. https://www.jove.com/v/55522 898 2017-10-20T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63738.jpg Microsurgical Creation of Giant Bifurcation Aneurysms in Rabbits for the Evaluation of Endovascular Devices Here, we describe the technique for the microsurgical creation of giant bifurcation aneurysms in rabbits for the evaluation of endovascular devices. https://www.jove.com/v/63738 441 2023-09-08T21:30:00+00:00 JoVE no https://visualize.jove.com/11892505-office-based-anesthesia-for-children monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2364.jpg Guidelines for Elective Pediatric Fiberoptic Intubation We describe guidelines to perform a safe and efficient elective fiberoptic intubation in pediatric patients while maintaining spontaneous ventilation. https://www.jove.com/v/2364 679 2011-01-18T03:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14500.jpg Local Anesthetics: Common Agents and Their Applications Local anesthetics (LAs) are commonly used for various applications in medical and dental procedures. Some of the common agents used are cocaine, lidocaine, and bupivacaine. Cocaine is an ester of benzoic acid and methylecgogine. It is used to anesthetize and vasoconstrict locally. Currently, it is used primarily for topical applications. It is beneficial for surgeries on the upper respiratory tract, providing anesthesia and shrinking the mucosa. Cocaine in the form of cocaine hydrochloride is... https://www.jove.com/v/14500 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14503.jpg Local Anesthetics: Clinical Application as Spinal Anesthesia Spinal anesthetics are given during lower abdomen and limb surgeries to block sensory and motor neurons. They are administered in the mid to low lumbar regions, primarily acting on the cauda equina's nerve roots. The blockade level depends on the local anesthetic (LA) concentration. Usually, low LA concentrations are sufficient to block sensory fibers, while only high LA concentrations block motor fibers. Other factors like injection volume and speed, the patient's posture, and the drug... https://www.jove.com/v/14503 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14748.jpg Local Anesthetics: Clinical Application as Epidural Anesthesia Epidural anesthetics are administered in the fat-filled epidural space, the outermost part of the spinal canal. This technique is commonly employed for pain management and anesthesia during lower abdomen and pelvis surgeries or labor and delivery. Since epidural anesthetics can be infused through an epidural catheter, all types of drugs, including short-acting ones, can be administered. Chloroprocaine and lidocaine are examples of short and long-duration anesthetics, respectively. Bupivacaine... https://www.jove.com/v/14748 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15188.jpg General Anesthesia: Overview Anesthesia is a medical procedure that uses drugs for CNS suppression to enable painless surgeries and procedures. The selection of anesthetics is influenced by their pharmacokinetic properties, side effects, and patient characteristics. Various types of anesthesia include general, local, regional, spinal, and inhalational. General anesthesia induces unconsciousness in the whole body, while the others target specific areas or sensations. It is administered to minimize adverse effects, maintain... https://www.jove.com/v/15188 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15190.jpg Parenteral Anesthetics: Overview Intravenous anesthetics are drugs administered parenterally to induce anesthesia or sedation. Propofol is a widely used agent formulated as a 1% emulsion in soybean oil, glycerol, and egg phosphatide. It induces rapid anesthesia primarily due to its rapid distribution from the bloodstream to target tissues and is metabolized in the liver. However, it can cause significant pain on injection and hypertriglyceridemia. Fospropofol, a water-based prodrug of propofol, lacks these adverse effects. https://www.jove.com/v/15190 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15191.jpg Inhalational Anesthetics: Overview Inhalation anesthetics are drugs that induce general anesthesia upon inhalation. They work by increasing the sensitivity of GABAA receptors or inhibiting NMDA receptors, leading to a decrease in central nervous system activity. The depth of anesthesia can be rapidly adjusted by changing the concentration of the inhaled gas. Some common examples of inhalational anesthetics include volatile liquids like isoflurane, desflurane, sevoflurane and gases like xenon and nitrous oxide. Isoflurane, a... https://www.jove.com/v/15191 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59702.jpg CO 2 -Lasertonsillotomy Under Local Anesthesia in Adults CO2-lasertonsillotomy under local anesthesia is an interesting alternative treatment method for tonsillectomy under general anesthesia for tonsil-related complaints in adults. This report presents a step-by-step protocol detailing the execution of CO2-lasertonsillotomy under local anesthesia. https://www.jove.com/v/59702 307 2019-11-06T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64004.jpg Anesthesia and Intubation of Preadolescent Mouse Pups for Cardiothoracic Surgery Cardiothoracic surgical models in mice >7 days old require intubation, but this is challenging for preadolescent (8-14-day-old) mouse pups and there is little information on anesthetic regimens for intubation. Here, we present dosage regimens of ketamine/xylazine/atropine in 10-day-old C57BL/6J mouse pups that allow endotracheal intubation, while minimizing animal mortality. https://www.jove.com/v/64004 587 2022-06-02T21:30:00+00:00 JoVE no https://visualize.jove.com/11932026-automated-detection-of-low-dimensional-eeg-alpha-episodes-an-example-of-application-to-psychopharmacological-data monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/51705.jpg Cortical Source Analysis of High-Density EEG Recordings in Children In recent years, there has been increasing interest in estimating the cortical sources of scalp measured electrical activity for cognitive neuroscience experiments. This article describes how high density EEG is acquired and how recordings are processed for cortical source estimation in children from the age of 2 years at the London Baby Lab. https://www.jove.com/v/51705 572 2014-06-30T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55089.jpg Automatic Detection of Highly Organized Theta Oscillations in the Murine EEG Theta activity in the hippocampus is related to specific cognitive and behavioral stages. Here, we describe an analytical method to detect highly-organized theta oscillations within the hippocampus using a time-frequency (i.e., wavelet analysis)-based approach. https://www.jove.com/v/55089 575 2017-03-10T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65829.jpg BrainBeats as an Open-Source EEGLAB Plugin to Jointly Analyze EEG and Cardiovascular Signals The BrainBeats toolbox is an open-source EEGLAB plugin designed to jointly analyze EEG and cardiovascular (ECG/PPG) signals. It includes heartbeat-evoked potentials (HEP) assessment, feature-based analysis, and heart artifact extraction from EEG signals. The protocol will aid in studying brain-heart interplay through two lenses (HEP and features), enhancing reproducibility and accessibility. https://www.jove.com/v/65829 502 2024-04-26T19:40:00+00:00 JoVE no https://visualize.jove.com/11936680-model-based-advanced-process-control-of-coagulation monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14619.jpg Coagulation Colloidal solids are solid particles suspended in solution. They are usually negatively charged, attracting a compact primary layer of positively charged ions, which attract more counterions to form an electrical double layer. Electrostatic repulsion between the charged double layers prevents the particles from colliding, stabilizing the colloids. These solids are often undesirable because they can contain toxins that are difficult to remove. Coagulation is a technique that helps aggregate and... https://www.jove.com/v/14619 66 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15256.jpg Coagulation The coagulation phase is a critical part of the body's process to prevent blood loss following injury to blood vessels. It involves chemical reactions that form a clot to seal the injured area. The clotting process begins shortly after injury, within 15-20 seconds for severe damage and 1-2 minutes for minor injuries. During the coagulation phase, clotting factors, or procoagulants, play a vital role in initiating and progressing the coagulation cascade. This cascade is a series of reactions... https://www.jove.com/v/15256 69 JoVE no https://cloudfront.jove.com/files/ftp_upload/40769/40769_article_thumb_40769.jpg Bioreactor Controls-I Maintaining optimal conditions within fermenters is essential for maximizing microbial productivity and ensuring process efficiency. This lesson focuses on key parameters—temperature, foam, pH, carbon dioxide, oxygen, and pressure—and their precise measurement and control strategies in fermentation systems.Temperature ControlTemperature regulation is critical due to the exothermic nature of many fermentation processes. In small laboratory fermenters, temperature is commonly monitored using... https://www.jove.com/v/40769 88 2026-03-12T20:57:37+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40770/40770_article_thumb_40770.jpg Bioreactor Controls-II In aerobic fermentations, oxygen is vital for microbial growth and metabolite production. Since air comprises only about 20% oxygen and the gas is poorly soluble in water—just 9 ppm at 20°C—supplying sufficient oxygen becomes a critical challenge, especially in high-demand processes like yeast growth or citric acid production. Even a fully saturated broth may offer only a few seconds of oxygen availability.To address this, sterile or scrubbed air is introduced into the fermentor via a sparger... https://www.jove.com/v/40770 78 2026-03-12T20:57:26+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40771/40771_article_thumb_40771.jpg Bioreactor Controls-III Strain improvement is a foundational strategy in industrial microbiology aimed at maximizing microbial productivity, particularly because natural isolates typically yield commercially valuable products in very low concentrations. Although optimizing the culture medium and environmental conditions can improve yields, these adjustments are inherently limited by the organism’s genetic potential. As a result, the focus shifts toward genetic modifications to enhance biosynthetic capacity. The... https://www.jove.com/v/40771 82 2026-03-12T20:57:27+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40777/40777_article_thumb_40777.jpg Upstream Processing Upstream processing represents a critical phase in biomanufacturing, wherein biological systems such as microorganisms, mammalian cells, or insect cells are cultivated to produce therapeutic proteins, vaccines, enzymes, or other biologically derived products. This phase encompasses all steps from the selection and genetic manipulation of the production organism to the cultivation of cells in bioreactors under tightly controlled environmental conditions.Host Selection and Genetic OptimizationThe... https://www.jove.com/v/40777 87 2026-03-12T20:57:34+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55351.jpg A Microfluidic Flow Chamber Model for Platelet Transfusion and Hemostasis Measures Platelet Deposition and Fibrin Formation in Real-time This paper describes an experimental model of hemostasis that simultaneously measures platelet function and coagulation. Platelet and fibrin fluorescence is measured in real-time, and platelet adhesion rate, coagulation rate, and onset of coagulation are determined. The model is used to determine platelet procoagulant properties under flow in concentrates for transfusion. https://www.jove.com/v/55351 578 2017-02-14T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60423.jpg Automated Counterflow Centrifugal System for Small-Scale Cell Processing Automation is key to upscaling and cost management in cell manufacturing. This manuscript describes the use of a counterflow centrifugal cell processing device for automating the buffer exchange and cell concentration steps for small-scale bioprocessing. https://www.jove.com/v/60423 289 2019-12-12T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63342.jpg Interactive and Visualized Online Experimentation System for Engineering Education and Research This work describes an online experimentation system that provides visualized experiments, including the visualization of theories, concepts, and formulas, visualizing the experimental process with three-dimensional (3-D) virtual test rigs, and visualizing the control and monitoring system using widgets such as charts and cameras. https://www.jove.com/v/63342 515 2021-11-24T22:00:00+00:00 JoVE no https://visualize.jove.com/11958448-advanced-cardiac-life-support-for-the-new-millennium monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17931/17931_article_thumb_17931.jpg Acute Coronary Syndrome IV: Interprofessional Care IntroductionThe management of Acute Coronary Syndrome (ACS) aims to minimize myocardial damage, preserve myocardial function, and prevent complications.Initial ManagementInpatient management involves continuous cardiac monitoring, preferably in an ICU, focusing on blood pressure, serum sodium, potassium, and creatinine levels, and urine output. Ongoing pharmacologic management is crucial for stabilizing the patient.Supplemental Oxygen: Administer supplemental oxygen if oxygen saturation is... https://www.jove.com/v/17931 88 2025-06-19T16:29:05+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17946/17946_article_thumb_17946.jpg Cardiopulmonary Resuscitation I: Adult Cardiopulmonary resuscitation, or CPR, is a life-saving emergency procedure performed when a person's heart has stopped beating or they are no longer breathing. The foundation of CPR is Basic Life Support (BLS), which focuses on the early recognition of cardiac arrest, the immediate start of high-quality chest compressions, and the timely use of an automated external defibrillator (AED).Assessing Responsiveness and Checking the Carotid PulseWhen approaching an unresponsive person, first ensure... https://www.jove.com/v/17946 81 2025-08-11T17:00:30+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17947/17947_article_thumb_17947.jpg Cardiopulmonary Resuscitation II: ACLS Airway Management Airway management is a key skill in emergency and critical care settings, as maintaining a clear airway is essential for adequate oxygenation and ventilation.Head Tilt-Chin Lift TechniqueThe head tilt-chin lift maneuver is an essential technique primarily used in patients without suspected cervical spine injuries. To perform this maneuver, one hand is placed on the patient’s forehead, and gentle pressure is applied backward to tilt the head. The fingertips of the other hand are positioned under... https://www.jove.com/v/17947 82 2025-06-19T16:38:19+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17948/17948_article_thumb_17948.jpg Cardiopulmonary Resuscitation III: AED Use Introduction to AEDAn Automated External Defibrillator (AED) is a portable medical device that analyzes the heart's rhythm and, if necessary, delivers an electrical shock to help the heart re-establish an effective rhythm during sudden cardiac arrest (SCA). SCA occurs when the heart suddenly and unexpectedly stops beating, leading to a loss of blood flow to the brain and other vital organs. In such emergencies, time is of the essence, and using an AED, combined with Cardiopulmonary... https://www.jove.com/v/17948 83 2025-06-19T16:38:36+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17949/17949_article_thumb_17949.jpg Cardiopulmonary Resuscitation IV: Pharmacological Management Pharmacologic intervention is crucial in treating cardiac arrest patients during ACLS or Advanced Cardiovascular Life Support. The ACLS algorithms guide the administration of specific drugs based on the patient's cardiac arrest rhythm, which includes pulseless ventricular tachycardia (VT), ventricular fibrillation (VF), asystole, and pulseless electrical activity (PEA).EpinephrineIndication: Epinephrine is the first-line drug for all cardiac arrest rhythms.Mechanism of Action: Epinephrine... https://www.jove.com/v/17949 85 2025-07-31T20:24:37+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17950/17950_article_thumb_17950.jpg Cardiopulmonary Resuscitation V: Advanced Airway Management Techniques Airway management is essential in emergency and surgical medicine, ensuring ventilation and oxygenation in patients who cannot maintain their own airway. Clinicians use a range of techniques and devices to secure the airway, depending on the patient’s condition and the clinical context. Key methods include endotracheal intubation, rapid sequence intubation (RSI), supraglottic airway devices, and advanced visualization aids. In cases where these approaches fail, surgical airway interventions are... https://www.jove.com/v/17950 90 2025-06-19T16:39:17+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59144.jpg Ultrasonographic Assessment During Cardiopulmonary Resuscitation Here, we present a US-CAB (Ultrasound, Circulation/Airway/Breathing) protocol for use during cardiopulmonary resuscitation (CPR). US-C evaluates the subxiphoid view of the heart and inferior vena cava. After intubation, tracheal US (US-A) and lung US (US-B) help confirm endotracheal intubation and proper ventilation. https://www.jove.com/v/59144 364 2020-10-24T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60707.jpg Standardized Model of Ventricular Fibrillation and Advanced Cardiac Life Support in Swine Cardiopulmonary resuscitation and defibrillation are the only effective therapeutic options during cardiac arrest caused by ventricular fibrillation. This model presents a standardized regimen to induce, assess, and treat this physiological state in a porcine model, thus providing a clinical approach with various opportunities for data collection and analysis. https://www.jove.com/v/60707 336 2020-01-30T23:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64931.jpg A Modified Sonographic Algorithm for Image Acquisition in Life-Threatening Emergencies in the Critically Ill Newborn Here, we present a protocol that can be applied in the neonatal intensive care unit and the delivery room in relation to three scenarios: cardiac arrest, hemodynamic deterioration, or respiratory decompensation. This protocol can be performed with a state-of-the-art ultrasound machine or an affordable handheld device; an image acquisition protocol is carefully detailed. https://www.jove.com/v/64931 687 2023-04-07T20:00:00+00:00 JoVE no https://visualize.jove.com/11980139-use-of-a-salivary-alpha-amylase-inhibitor-in-the-saliva-biochemical-study monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3999.jpg The α-test: Rapid Cell-free CD4 Enumeration Using Whole Saliva A CD4 enumeration method, the α-test, is described which uses whole saliva to provide rapid and accurate CD4 counts. The α-test costs pennies and eliminates the need for technical training, costly reagents such as monoclonal antibodies, instrumentation, refrigeration, transport of samples, as well as collection and handling of blood. https://www.jove.com/v/3999 682 2012-05-16T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10832.jpg Lipid Digestion Lipids are large molecules that are generally not water-soluble. Since most of the digestive enzymes in the human body are water-based, there are specific steps the body must take to break down lipids and make them available for use. Lingual Lipase and Gastric Lipase Lingual lipase is an enzyme secreted by the acinar cells of the sublingual gland that aids lipid digestion. Although found in saliva, it plays only a minimal role in breaking down lipids in the mouth. Interestingly, lingual... https://www.jove.com/v/10832 66 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10834.jpg Carbohydrate Digestion Carbohydrate digestion and metabolism break down simple and complex carbohydrates from food into saccharides (i.e., sugars) for the body to use as energy. Carbohydrate digestion starts in the mouth during mastication, or chewing. The masticated carbohydrates remain intact in the stomach. Digestion resumes in the duodenum of the small intestine, where pancreatic alpha-amylase and brush border enzymes of the microvilli convert complex carbohydrates to monosaccharides. Finally, the monosaccharides... https://www.jove.com/v/10834 57 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16187.jpg Salivary Glands and Saliva The salivary glands, of which there are three pairs known as the parotid, submandibular, and sublingual glands, play a crucial role in maintaining oral health and initiating the digestive process. Positioned near the ears, beneath the masseter muscle, the parotid glands secrete saliva into the oral cavity through the parotid duct of Stensen. Meanwhile, the submandibular glands, located on the floor of the mouth, secrete saliva through channels named submandibular ducts. The sublingual glands,... https://www.jove.com/v/16187 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50815.jpg Collecting Saliva and Measuring Salivary Cortisol and Alpha-amylase in Frail Community Residing Older Adults via Family Caregivers We demonstrate: (1) procedures for collection of salivary samples in cognitive impaired older adults by family caregivers in the home setting, (2) procedures for measuring stress activity via salivary cortisol and alpha amylase, and (3) representative profiles. Protocols that allow researchers to study stress-linked processes advance our understanding of biological sensitivity and susceptibility. https://www.jove.com/v/50815 505 2013-12-18T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59272.jpg Measuring Biophysical and Psychological Stress Levels Following Visitation to Three Locations with Differing Levels of Nature The purpose of this paper is to identify changes in stress levels after visitation to three different settings and to describe the methods used in identifying stress levels based on measures of salivary cortisol, α-amylase, and a psychological self-report... https://www.jove.com/v/59272 333 2019-06-19T20:00:00+00:00 JoVE no https://visualize.jove.com/12027565-alpha-satellite-dna-and-vector-composition-influence-rates-of-human-artificial-chromosome-formation monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3150.jpg Quantitation and Analysis of the Formation of HO-Endonuclease Stimulated Chromosomal Translocations by Single-Strand Annealing in Saccharomyces cerevisiae The HO-stimulated translocation assay monitors single-strand annealing following the creation of DNA double-strand breaks at multiple loci in diploid Saccharomyces cerevisiae. This mechanism may model genome rearrangements in somatic cells of higher eukaryotes following exposure to high doses of ionizing radiation. https://www.jove.com/v/3150 580 2011-09-23T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/3819.jpg Engineering and Evolution of Synthetic Adeno-Associated Virus (AAV) Gene Therapy Vectors via DNA Family Shuffling We demonstrate the basic technique to molecularly engineer and evolve synthetic Adeno-associated viral (AAV) gene therapy vectors via DNA family shuffling. Moreover, we provide general guidelines and representative examples for selection and analysis of individual chimeric capsids with enhanced properties on target cells in culture or in mice. https://www.jove.com/v/3819 1315 2012-04-02T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11529.jpg Chromosome Structure A functional eukaryotic chromosome must contain three elements: a centromere, telomeres, and numerous origins of replication. The centromere is a DNA sequence that links sister chromatids. This is also where kinetochores, protein complexes to which spindle microtubules attach, are constructed after the chromosome is replicated. The kinetochores allow the spindle microtubules to move the chromosomes within the cell during cell division. Telomeres consist of non-coding repetitive nucleotide... https://www.jove.com/v/11529 160 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11540.jpg Polytene Chromosomes Polytene chromosomes are giant interphase chromosomes with several DNA strands placed side by side. They were discovered in the year 1881 by Balbiani in salivary glands, intestine, muscles, malpighian tubules, and hypoderm of larvae Chironomus plumosus. Hence, these are also called "Salivary gland chromosomes." These are found in insects of the order Diptera and Collembola; in certain organs of mammals; and synergids, antipodes of flowering plants. Polytene chromosomes are also regularly... https://www.jove.com/v/11540 124 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11541.jpg Histone Variants at the Centromere Histone variants are the histone proteins with structural and sequence variations. These variants may be regarded as “mutant” forms that replace their canonical histone counterparts in the nucleosomes. Specific post-translational modifications on the histone variants enable further chromatin complexity and regulate tissue-specific gene expression. The most common histone variants are from histone H2A, H2B, and linker histone H1 families. However, several variants of histone H3 variants are also... https://www.jove.com/v/11541 150 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11542.jpg Inheritance of Chromatin Structures Epigenetics is the study of inherited changes in a cell's phenotype without changing the DNA sequences. It provides a form of memory for the differential gene expression pattern to maintain cell lineage, position-effect variegation, dosage compensation, and maintenance of chromatin structures such as telomeres and centromeres. For example, the structure and location of the centromere on chromosomes are epigenetically inherited. Its functionality is not dictated or ensured by the underlying DNA... https://www.jove.com/v/11542 197 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11544.jpg Chromatin Position Affects Gene Expression Chromatin is the massive complex of DNA and proteins packaged inside the nucleus. The complexity of chromatin folding and how it is packaged inside the nucleus greatly influences access to genetic information. Generally, the nucleus' periphery is considered transcriptionally repressive, while the cell's interior is considered a transcriptionally active area. Topologically Associated Domains (TADs) The 3-dimensional positioning of chromatin in the nucleus influences the timing and level of... https://www.jove.com/v/11544 155 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12053.jpg Duplication of Chromatin Structure The process of chromosome duplication during cell division requires genome-wide disruption and re-assembly of chromatin. The chromatin structure must be accurately inherited, reassembled, and maintained in the daughter cells to ensure lineage propagation. The basic unit of the chromatin is the nucleosome, consisting of DNA wrapped around octameric histone proteins and short stretches of linker DNA separating individual nucleosomes. The histone proteins within the nucleosome have their... https://www.jove.com/v/12053 125 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53164.jpg Bacterial Artificial Chromosomes: A Functional Genomics Tool for the Study of Positive-strand RNA Viruses Here, a protocol is presented for creating an infectious bacterial artificial chromosome containing a full-length cDNA of the positive-strand genomic RNA of Japanese encephalitis virus. This protocol can be used to construct a functional cDNA of other positive-strand RNA viruses, making it a powerful genomic tool for studying virus biology. https://www.jove.com/v/53164 740 2015-12-29T21:00:00+00:00 JoVE no https://visualize.jove.com/12040892-acth-treatment-of-infantile-spasms-mechanisms-of-its-effects-in-modulation-of-neuronal-excitability monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14454.jpg Indirect-Acting Cholinergic Agonists: Pharmacological Actions Indirect-acting cholinergic agonists, also known as anticholinesterases, exert their pharmacological effects by enhancing cholinergic transmission in various body parts, including the neuromuscular junction, autonomic cholinergic synapses, and the brain. At the neuromuscular junction, these agents work by inhibiting the breakdown of acetylcholine, allowing it to remain bound to the receptor and bind to nearby receptors. This process leads to repetitive firing of the endplate, causing muscle... https://www.jove.com/v/14454 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14484.jpg Classification of Skeletal Muscle Relaxants Skeletal muscle relaxants are a group of drugs that can reduce muscle stiffness and induce temporary paralysis to relieve pain. These agents can act centrally to reduce muscle tone or spasms in painful conditions such as multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), or spinal injuries; they are called antispasmodics or spasmolytics. Peripherally acting skeletal muscle relaxants interfere with the neurotransmission at the neuromuscular end plate to induce paralysis during... https://www.jove.com/v/14484 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14492.jpg Skeletal Muscle Relaxants: Therapeutic Uses Skeletal muscle relaxants are used to relax muscle tone and alleviate painful muscle contractions. However, the choice of skeletal muscle relaxants depends on the duration of the surgical procedure in order to minimize potential side effects. Skeletal muscle relaxants like neuromuscular blocking agents [NMBAs] are commonly employed as adjuvants alongside general anesthetics in clinical settings. NMBAs are also used to maintain controlled ventilation during surgery of the larynx or pharynx as... https://www.jove.com/v/14492 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14493.jpg Spasmolytic Agents: Chemical Classification Spasmolytic agents are drugs used to alleviate muscle spasms and spasticity. They can be categorized into different chemical groups based on their mechanisms of action. Centrally acting spasmolytics primarily affect the spinal cord, while others directly target skeletal muscle cells. A major class of centrally acting spasmolytics is the α2-agonist, such as tizanidine. These drugs bind to α2-adrenoceptors, inhibiting the release of the excitatory neurotransmitter glutamate. They also promote... https://www.jove.com/v/14493 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14495.jpg Centrally Acting Muscle Relaxants: Therapeutic Uses Centrally acting muscle relaxants reduce muscle tone and tension by interfering with the postsynaptic reflexes in the central nervous system. Centrally acting drugs are classified into spasmolytic and antispasmodic drugs. Spasmolytic drugs such as baclofen, diazepam, and tizanidine inhibit spinal motor neurons and decrease muscle tone. Spasmolytic drugs are administered for severe and chronic spasms due to multiple sclerosis, cerebral palsy, stroke, and spinal cord and muscle injuries. However,... https://www.jove.com/v/14495 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15220.jpg Antiepileptic Drugs: Modulators of Neurotransmitter Release Mediated by SV2A Protein Antiepileptic drugs, such as levetiracetam (Keppra) and brivaracetam (Briviact), have emerged as crucial tools in managing epilepsy. These medications exert their therapeutic effects by targeting the synaptic vesicle protein SV2A, a transmembrane glycoprotein primarily found in the brain. SV2A is a transmembrane glycoprotein located predominantly in the brain, modulating the release of neurotransmitters for neuronal communication. Both levetiracetam and brivaracetam exhibit a high affinity for... https://www.jove.com/v/15220 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59268.jpg Electrophoretic Delivery of γ-aminobutyric Acid (GABA) into Epileptic Focus Prevents Seizures in Mice The challenge of epilepsy research is to develop novel treatments for patients where classical therapy is inadequate. Using a new protocol—with the help of an implantable drug delivery system—we are able to control seizures in anesthetized mice by the electrophoretic delivery of GABA into the epileptic focus. https://www.jove.com/v/59268 421 2019-05-16T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65659.jpg Enhancing the Development and Growth of Infant Cerebral Palsy Rats Using Selective Spinal Manipulations This study illustrates the effect of selective spinal manipulation on the growth and development of infant rats with cerebral palsy, emphasizing the specific procedure and standardized protocol. Body weight measurement, Rotarod test, Foot-fault score, other behavioral tests, and growth hormone detection were performed to evaluate the protocol. https://www.jove.com/v/65659 304 2024-02-02T21:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66013.jpg Repeated Transcranial Magnetic Stimulation Combined with Action Observation Training in Children with Spastic Cerebral Palsy Children with spastic cerebral palsy (SCP) have limb spasticity, movement disorders, and abnormal posture due to injury to the cerebral cortex motor area, resulting in inability to stand and walk normally. Therefore, alleviating limb spasticity and enhancing gross motor function in children with SCP have become important therapeutic goals. https://www.jove.com/v/66013 440 2024-08-09T19:40:00+00:00 JoVE no https://visualize.jove.com/12053392-occlusion-of-interatrial-communications-with-the-amplatzer-device-experience-in-48-consecutive-patients monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3818.jpg Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation Catheter ablation is combined with placement of the WATCHMAN Left Atrial Appendage Closure Device to prevent ischemic stroke in a patient with non-valvular atrial fibrillation. https://www.jove.com/v/3818 2013-02-26T19:57:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61240.jpg Echocardiographic Evaluation of Atrial Communications before Transcatheter Closure Transthoracic (TTE) and transesophageal (TEE) echocardiography represent the basic imaging tools for interatrial septum examination. Three dimensional (3D) TEE provides incremental information in the assessment of the interatrial septum. Further advanced echocardiography techniques using speckle tracking echocardiography are applied for sensitive volumetric and functional assessment of the heart... https://www.jove.com/v/61240 461 2022-02-08T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63663.jpg Closure of a Patent Foramen Ovale (PFO): An Intervention Sequence The closure of a patent foramen ovale (PFO) is a catheter-based intervention to prevent PFO-associated stroke. The PFO-occlusion device is advanced through the femoral vein and deployed across the interatrial septum using transesophageal echocardiography (TEE) and fluoroscopic guidance. The following protocol provides a step-by-step guide for the PFO-closure intervention using a double-disc device. https://www.jove.com/v/63663 652 2022-12-23T20:30:00+00:00 JoVE no https://visualize.jove.com/12065838-aid-enzyme-induced-hypermutation-in-an-actively-transcribed-gene-in-fibroblasts monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3573.jpg Assessing Somatic Hypermutation in Ramos B Cells after Overexpression or Knockdown of Specific Genes We describe how to perform retroviral or lentiviral infections of overexpression or shRNA-containing constructs in the human Ramos B-cell line and how to measure somatic hypermutation in these cells. https://www.jove.com/v/3573 492 2011-11-01T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/4110.jpg High-throughput Purification of Affinity-tagged Recombinant Proteins We describe a method for the affinity-tagged purification of recombinant proteins using liquid-handling robotics. This method is generally applicable to the small-scale purification of soluble His-tagged proteins in a high-throughput format. https://www.jove.com/v/4110 464 2012-08-26T14:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10827.jpg Viral Mutations A mutation is a change in the sequence of bases of DNA or RNA in a genome. Some mutations occur during replication of the genome due to errors made by the polymerase enzymes that replicate DNA or RNA. Unlike DNA polymerase, RNA polymerase is prone to errors because it is not capable of “proofreading” its work. Viruses with RNA-based genomes, like HIV, therefore accrue mutations faster than viruses with DNA-based genomes. Because mutation and recombination provide the raw material for adaptive... https://www.jove.com/v/10827 36 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11566.jpg DNA Damage can Stall the Cell Cycle In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at... https://www.jove.com/v/11566 156 2025-12-12T13:27:29+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11988.jpg Genome Copying Errors DNA replication is a well-evolved process that copies millions of base pairs with high fidelity during each cell division. Occasionally a wrong base or a long stretch of wrong bases may get added to the daughter strands. If the errors are left unchecked, cells might accumulate several mutations that might endanger their survival. Therefore, the copying errors are checked and repaired at three levels. Proofreading - DNA polymerase enzymes, for example, introduce 1 incorrect nucleotide per... https://www.jove.com/v/11988 166 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11566.jpg DNA Damage Can Stall the Cell Cycle In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at... https://www.jove.com/v/13205 156 2025-12-12T13:26:51+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19543/19543_article_thumb_19543.jpg Mutations in Microorganisms Mutations are heritable changes in an organism’s genome involving alterations in the base sequence of DNA or RNA. These changes can influence cellular processes and phenotypic traits, potentially transforming the unaltered wild type into a mutant form. Such changes, termed forward mutations, are pivotal in shaping the genetic diversity of organisms.RNA viruses exhibit the highest mutation rates due to the absence of robust proofreading mechanisms during genome replication. In contrast,... https://www.jove.com/v/19543 78 2025-06-12T09:16:43+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19544/19544_article_thumb_19544.jpg Spontaneous and Induced Mutations Spontaneous mutations arise infrequently during DNA replication due to errors in the process. A key factor behind these errors is tautomeric shifts in nitrogenous bases, where bases transition from keto to enol forms or amino to imino forms. This shift can alter base-pairing rules, leading to mutations. Additionally, reactive oxygen species (ROS) arising from aerobic metabolism can damage DNA, resulting in depurination (loss of a purine base) or depyrimidination (loss of a pyrimidine base). https://www.jove.com/v/19544 90 2025-06-12T09:16:54+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51551.jpg Aip1p Dynamics Are Altered by the R256H Mutation in Actin Disease-causing mutations in actin can alter cytoskeletal function. Cytoskeletal dynamics are quantified through imaging of fluorescently tagged proteins using total internal fluorescence microscopy. As an example, the cytoskeletal protein, Aip1p, has altered localization and movement in cells expressing the mutant actin isoform, R256H. https://www.jove.com/v/51551 537 2014-07-30T14:00:00+00:00 JoVE no https://visualize.jove.com/12075672-extending-ventilation-duration-estimations-approach-from-adult-to-neonatal-intensive-care-patients-using-artificial-neural-networks monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13299.jpg Assessment of Ventilation I: Respiratory Rate Assessment of Ventilation A Ventilation assessment is critical for monitoring a patient's health status. Respiration, one of the most accessible vital signs, provides insights into the function of numerous body systems and can indicate serious health issues, such as brainstem injuries from head trauma. Critical Guidelines for Assessing Ventilation: Unobtrusive Observation: Maintaining accuracy in ventilation assessment is paramount. Observing the patient's breathing without their knowledge is... https://www.jove.com/v/13299 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15706.jpg Neural Control of Respiration The neural regulation of respiration is a meticulously coordinated process primarily controlled by the respiratory centers located within the brainstem. These centers, composed of specialized neurons, transmit nerve impulses that control the contraction and relaxation of our respiratory muscles. Respiratory Centers in the Brainstem Two primary areas comprise the respiratory center: the medullary respiratory center in the medulla oblongata and the pontine respiratory group in the pons. The... https://www.jove.com/v/15706 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16399.jpg Mechanical Ventilation II: Invasive Ventilation Ventilators are essential medical equipment used to aid patients with respiratory difficulties. Their primary function is to assist or replace spontaneous breathing by providing mechanical ventilation. There are two general classes of mechanical ventilators: negative-pressure and positive-pressure ventilators. Negative-Pressure Ventilators Negative-pressure ventilators create a vacuum around the chest or body to draw air into the lungs, simulating breathing. This method does not require an... https://www.jove.com/v/16399 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16400.jpg Mechanical Ventilation III: Noninvasive Ventilation Noninvasive positive-pressure ventilation (NIPPV), continuous positive airway pressure (CPAP), and bilevel positive airway pressure (BiPAP) are essential methods in respiratory care. These ventilation techniques offer unique benefits for patients with various respiratory conditions, providing adequate support without requiring intubation. Let's explore how each method is crucial in improving patient outcomes and enhancing respiratory therapy. Noninvasive Positive-Pressure Ventilation (NIPPV)<br... https://www.jove.com/v/16400 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16401.jpg Ventilatory Modes Mechanical ventilators are life-saving devices that support or replace spontaneous breathing. They deliver breaths to patients through varying methods known as ventilator modes. Understanding these modes is critical for healthcare providers managing patients with respiratory failure. There are three ventilatory modes: full support, partial support, and spontaneous. These are described below. Full Support Modes Full support modes include controlled mechanical ventilation, continuous mandatory... https://www.jove.com/v/16401 74 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64706.jpg Laryngeal Mask Airway (LMA) Placement in a Neonatal Patient Simulator Using a Non-Inflatable Supraglottic Airway (SGA) This protocol is designed to describe a method to place and establish a supraglottic (alternative) airway during neonatal resuscitation. It can be used in situations where frontline providers cannot ventilate or endotracheally intubate neonates requiring resuscitation. https://www.jove.com/v/64706 296 2023-07-14T21:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66385.jpg Three-Dimensional Phase Resolved Functional Lung Magnetic Resonance Imaging Three-dimensional (3D) phase-resolved functional lung (PREFUL) is a functional magnetic resonance imaging (MRI) technique that allows for quantification of regional ventilation of the whole human lung volume, using tidal breathing and contrast-agent free acquisition for 8 min. Here, we present an MR protocol to collect and analyze 3D PREFUL imaging data. https://www.jove.com/v/66385 644 2024-06-21T20:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68510.jpg A Structured Approach to Extubation in Mechanically Ventilated Rats This study proposes a structured extubation approach tailored to rat models of mechanical ventilation (MV). The approach facilitates a smooth transition from MV to spontaneous breathing while minimizing extubation-related complications. Standardization of weaning, airway management, and post-extubation care enhances the reliability and reproducibility of experimental studies. https://www.jove.com/v/68510 305 2025-07-18T23:20:00+00:00 JoVE no https://visualize.jove.com/12090640-the-application-of-analysis-of-variance-anova-to-different-experimental-designs-in-optometry monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13619.jpg What is an ANOVA? The Analysis of Variance or ANOVA is a statistical test developed by Ronald Fisher in 1918. It is performed on three or more samples to check for equality between their means. Before performing ANOVA, one must ensure that the samples used for this analysis have three crucial characteristics or statistical assumptions. The first assumption states that the samples should be drawn from normally distributed samples, while the second requires that all the drawn samples should be randomly and... https://www.jove.com/v/13619 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13620.jpg One-Way ANOVA One-way ANOVA analyzes more than three samples categorized by one factor. For example, it can compare the average mileage of sports bikes. Here, the data is categorized by one factor - the company. However, one-way ANOVA cannot be used to simultaneously compare the sample mean of three or more samples categorized by two factors. An example of two factors would be sports bikes from different companies driven in different terrains, such as a desert or snowy landscape. Here, two-way ANOVA is used... https://www.jove.com/v/13620 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13624.jpg Two-Way ANOVA The two-way ANOVA is an extension of the one-way ANOVA. It is a statistical test performed on three or more samples categorized by two factors - a row factor and a column factor. Ronald Fischer mentioned it in 1925 in his book 'Statistical Methods for Researchers.' The two-way ANOVA analysis initially begins by stating the null hypothesis that there is an interaction effect between the two factors of a dataset. This effect can be visualized using line segments formed by joining the means for... https://www.jove.com/v/13624 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16481.jpg Statistical Methods to Analyze Parametric Data: ANOVA Analysis of Variance, or ANOVA, is a powerful statistical technique used to analyze parametric data, primarily in research and experimental studies. It's designed to compare the means of two or more groups, assisting researchers in identifying any significant differences between these group means. There are two main types of ANOVA based on the complexity of the analysis: one-way and two-way. One-way ANOVA is applied when a single independent variable or factor is scrutinized. It compares the... https://www.jove.com/v/16481 72 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17358.jpg What is ANOVA? The Analysis of Variance or ANOVA is a statistical test developed by Ronald Fisher in 1918. It is performed on three or more samples to check for equality between their means. Before performing ANOVA, one must ensure that the samples used for this analysis have three crucial characteristics or statistical assumptions. The first assumption states that the samples should be drawn from normally distributed samples, while the second requires that all the drawn samples be randomly and independently... https://www.jove.com/v/17358 73 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17594.jpg Friedman Two-way Analysis of Variance by Ranks Friedman's Two-Way Analysis of Variance by Ranks is a nonparametric test designed to identify differences across multiple test attempts when traditional assumptions of normality and equal variances do not apply. Unlike conventional ANOVA, which requires normally distributed data with equal variances, Friedman's test is ideal for ordinal or non-normally distributed data, making it particularly useful for analyzing dependent samples, such as matched subjects over time or repeated measures from... https://www.jove.com/v/17594 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63421.jpg Application of Optical Coherence Tomography to a Mouse Model of Retinopathy Here, we describe an in vivo imaging technique using optical coherence tomography to facilitate the diagnosis and quantitative measurement of retinopathy in mice. https://www.jove.com/v/63421 502 2022-01-12T22:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63864.jpg Binocular Dynamic Visual Acuity in Eyeglass-Corrected Myopic Patients The present research demonstrates a method to accurately examine dynamic visual acuity (DVA) in myopic subjects with eyeglass correction. Further analysis indicated that the closer the refraction state to emmetropia, the better the eyeglass-corrected binocular DVA is at both 40 and 80 degrees per second. https://www.jove.com/v/63864 426 2022-03-29T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68422.jpg Comparison of Agreement and Accuracy using Binocular Wavefront Optometer with Autorefractor and Phoropter The binocular wavefront optometer agrees well with traditional refraction techniques in both objective and subjective refraction measurements, offering superior accuracy and clinical utility. Its standardized protocol reduces optometrist workload and provides a more accurate refractive assessment for post-refractive surgery individuals. https://www.jove.com/v/68422 314 2025-09-16T19:30:00+00:00 JoVE no https://visualize.jove.com/12139093-computer-aided-diagnosis-of-breast-tumors-with-different-us-systems monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4178.jpg Multi-modal Imaging of Angiogenesis in a Nude Rat Model of Breast Cancer Bone Metastasis Using Magnetic Resonance Imaging, Volumetric Computed Tomography and Ultrasound In the pathogenesis of bone metastasis, angiogenesis is a crucial process and therefore represents a target for imaging and therapy. Here, we present a rat model of site-specific breast cancer bone metastasis and describe strategies to non-invasively image angiogenesis in vivo using magnetic resonance imaging, volumetric computed tomography and ultrasound. https://www.jove.com/v/4178 743 2012-08-14T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59231.jpg Use of MRI-ultrasound Fusion to Achieve Targeted Prostate Biopsy Presented herein is a protocol to perform targeted biopsy of the prostate using an MRI-ultrasound fusion system. https://www.jove.com/v/59231 551 2019-04-09T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64864.jpg A Coregistered Ultrasound and Photoacoustic Imaging Protocol for the Transvaginal Imaging of Ovarian Lesions We report a coregistered ultrasound and photoacoustic imaging protocol for the transvaginal imaging of ovarian/adnexal lesions. The protocol may be valuable to other translational photoacoustic imaging studies, especially those using commercial ultrasound arrays for the detection of photoacoustic signals and standard delay-and-sum beamforming algorithms for imaging. https://www.jove.com/v/64864 621 2023-03-03T22:15:00+00:00 JoVE no https://visualize.jove.com/12145492-the-classification-of-anxiety-disorders-in-icd-10-and-dsm-iv-a-concordance-analysis monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2705.jpg The Successive Alleys Test of Anxiety in Mice and Rats The plus-maze measures anxiety-like behaviour in rodents. There are two opposite closed and two opposite open arms; anxious rodents avoid the open arms. The central area is neither completely open nor closed, so time spent here is ambiguous and difficult to interpret. Here a modification of the plus-maze protocol eliminating this area is described. https://www.jove.com/v/2705 305 2013-06-17T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13101.jpg Classification of Illness The meaning of illness is individualized to each person who experiences an alteration in health. In contrast, disease is a medical term indicating a pathological change in the structure and function of the body or mind. It is a condition that has specific symptoms and boundaries. An illness is a response to a disease in which the person's level of functioning is changed compared with a previous level. The general classification of illness includes acute and chronic. Acute illness is severe and... https://www.jove.com/v/13101 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15206.jpg Anxiety: Overview Anxiety is a common mental disorder featuring excessive worry, fear, and apprehension, significantly affecting daily life. People with anxiety disorders experience persistent and intense anxiety, interrupting their everyday functioning. Individuals with anxiety often experience a range of physical and emotional symptoms, including sweating, trembling, tachycardia, and disturbances in sleep patterns. These symptoms vary in intensity and frequency but are generally disruptive and distressing.<br... https://www.jove.com/v/15206 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18602.jpg Diagnostic and Statistical Manual of Mental Disorders (DSM) The Diagnostic and Statistical Manual of Mental Disorders (DSM) serves as the primary classification system for mental health disorders, providing standardized diagnostic criteria for clinicians and researchers. First published by the American Psychiatric Association (APA) in 1952, the DSM has undergone several revisions to reflect evolving psychiatric understanding. The fifth edition, DSM-5, released in 2013, introduced key updates that expanded diagnostic categories and modified diagnostic... https://www.jove.com/v/18602 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18603.jpg Generalized Anxiety Disorder Generalized Anxiety Disorder (GAD) is a chronic condition characterized by excessive and uncontrollable worry that persists for at least six months, significantly interfering with daily functioning. Unlike situational anxiety, which arises in response to specific stressors, GAD often occurs without a clear cause. Individuals may experience disproportionate worry about work, health, or relationships. For instance, a person might continuously fear poor health despite normal medical evaluations or... https://www.jove.com/v/18603 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18604.jpg Panic Disorder Panic disorder is an anxiety disorder characterized by recurrent and sudden minutes-long episodes of intense fear, known as panic attacks. These attacks may feel like heart attacks and often happen without warning or a specific cause. They can include symptoms such as rapid heart rate, shortness of breath, chest pain, trembling, sweating, dizziness, and a sense of helplessness. During a panic attack, individuals may feel as though they are experiencing a heart attack or are in a... https://www.jove.com/v/18604 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18605.jpg Social Anxiety Disorder Social anxiety disorder, also known as social phobia, is characterized by an intense fear of social situations where one might face humiliation, rejection, embarrassment, or negative evaluation. This disorder leads individuals to avoid activities like casual conversations, public speaking, or seemingly simple tasks such as eating, signing documents, or swimming, in public settings. Its impact extends beyond discomfort, often significantly interfering with daily functioning and quality of life.<br... https://www.jove.com/v/18605 88 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64567.jpg Social Isolation Model: A Noninvasive Rodent Model of Stress and Anxiety Presented here is a social isolation (SI)-induced anxiety mouse model that utilizes wild type C56BL/6J mice to induce stress and anxiety-like behavior with minimal handling and no invasive procedures. This model reflects modern life patterns of social isolation and is ideal for studying anxiety and related disorders. https://www.jove.com/v/64567 260 2022-11-11T22:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67770.jpg Polar Histogram Visualization of Acute Stress Disorder Scale Scores for Comprehensive Clinical Assessment This study introduces a novel polar histogram visualization method for analyzing Acute Stress Disorder Scale (ASDS) scores, focusing on elderly ICU caregivers. The technique displayed all 19 ASDS variables simultaneously, revealing distinct stress patterns between healthy controls and caregivers while demonstrating significant improvements post-intervention in hyperarousal and avoidance symptoms. https://www.jove.com/v/67770 505 2024-12-06T23:00:00+00:00 JoVE no https://visualize.jove.com/12161930-conceptual-tools-for-the-integration-of-data monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2397.jpg Facilitating the Analysis of Immunological Data with Visual Analytic Techniques Visual analytics (VA) is a new approach of analyzing data interactively. In this video, we discuss the data overload problem brought on by high-throughput biological experiments, and propose VA as a solution to such problem. The video demonstrates analysis within and between immunological datasets using a VA tool called Tableau. https://www.jove.com/v/2397 658 2011-01-03T01:00:00+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18134/18134_article_thumb_18134.jpg Introduction to GIS Geographic Information Systems (GIS) are tools for storing, analyzing, and displaying spatial data alongside related attributes. Unlike traditional information systems that address general queries, GIS incorporates spatial components, enabling users to answer "where" and "how far." For example, GIS can process housing data linked to geographic locations like zip codes, allowing insights into population density or housing distribution through thematic maps.GIS integrates technologies such as... https://www.jove.com/v/18134 88 2025-03-26T22:41:49+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18135/18135_article_thumb_18135.jpg Thematic Layering in GIS In the past, planning projects such as schools or public facilities required extensive manual effort to gather and compile data. Information such as property boundaries, soil characteristics, road networks, zoning regulations, and flood zones had to be sourced individually from courthouses, utility providers, and registry offices. Assembling these datasets into a coherent format often took several months, delaying project timelines.The introduction of Geographic Information Systems (GIS)... https://www.jove.com/v/18135 90 2025-03-26T22:41:53+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18136/18136_article_thumb_18136.jpg Levels of Use of a GIS Geographic Information Systems (GIS) operate across three levels of application, each representing an increasing degree of complexity: data management, analysis, and prediction. These levels reflect the expanding functionality and versatility of GIS technology in handling spatial data for diverse purposes.Data ManagementAt its foundational level, GIS serves as a tool for data management, enabling the input, storage, retrieval, and organization of spatial data. This level is often employed in... https://www.jove.com/v/18136 89 2025-03-26T22:41:58+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18137/18137_article_thumb_18137.jpg Selected Data About Geographic Locations Geographic Information Systems (GIS) rely on two core types of data: spatial data and attribute data.Spatial DataSpatial data defines the physical location of features within a coordinate system, typically expressed in terms of latitude and longitude. It provides precise positioning for elements like roads, rivers, or buildings.Attribute DataAttribute data complements spatial data by adding descriptive information about these features. For example, a road's spatial data includes its start and... https://www.jove.com/v/18137 85 2025-03-26T22:42:02+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18139/18139_article_thumb_18139.jpg Manipulation and Analysis GIS manipulation and analysis functions are vital for decision-making and planning. These activities range from data retrieval tasks, such as selecting information based on specific criteria, to advanced analytical techniques that address complex spatial problems.One critical GIS analysis method is overlaying, which combines multiple data layers to examine impacts. For example, overlaying a river-dammed lake boundary with road networks can identify affected infrastructure. Another common... https://www.jove.com/v/18139 81 2025-03-26T22:42:31+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19983/19983_article_thumb_19983_TN.jpg Application of Integration: Problem Solving The process of breathing involves the periodic intake and expulsion of air, known as the respiratory cycle, which typically lasts about five seconds. Modeling the volume of air inhaled into the lungs as a function of time provides insight into both the dynamics and efficiency of pulmonary ventilation. This volume is determined by integrating the airflow rate over time, which captures the cumulative effect of air entering the lungs.Sinusoidal Model of AirflowAirflow during respiration is not... https://www.jove.com/v/19983 90 2026-01-12T20:24:28+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60038.jpg Databases to Efficiently Manage Medium Sized, Low Velocity, Multidimensional Data in Tissue Engineering Many researchers generate "medium-sized", low-velocity, and multi-dimensional data, which can be managed more efficiently with databases rather than spreadsheets. Here we provide a conceptual overview of databases including visualizing multi-dimensional data, linking tables in relational database structures, mapping semi-automated data pipelines, and using the database to elucidate data meaning. https://www.jove.com/v/60038 583 2019-11-22T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65512.jpg CorrelationCalculator and Filigree: Tools for Data-Driven Network Analysis of Metabolomics Data We present CorrelationCalculator and Filigree, two tools for data-driven network construction and analysis of metabolomics data. CorrelationCalculator supports building a single interaction network of metabolites based on expression data, while Filigree allows building a differential network, followed by network clustering and enrichment analysis. https://www.jove.com/v/65512 431 2023-11-10T22:20:00+00:00 JoVE no https://visualize.jove.com/12189668-inhaled-steroids-in-asthma-should-the-doses-be-reduced monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2428.jpg Bronchial Thermoplasty: A Novel Therapeutic Approach to Severe Asthma Bronchial thermoplasty is a non-drug procedure for severe persistent asthma that delivers thermal energy to the airway wall in a precisely controlled manner to reduce excessive airway smooth muscle. Reducing airway smooth muscle decreases the ability of the airways to constrict, thereby reducing the frequency of asthma attacks. https://www.jove.com/v/2428 879 2010-11-05T00:10:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15224.jpg Drugs Used in Lower Respiratory Disorders: Overview Lower respiratory tract disorders present challenges that often require skilled and nuanced approaches for effective management. Common ailments, such as asthma and chronic obstructive pulmonary disease (COPD), have prompted the development of intricate treatment strategies involving bronchodilators and anti-inflammatory drugs, each tailored to ease breathing and revitalize the lungs. Bronchodilators, the first step of respiration enhancement, come in various forms, each with its own mechanism... https://www.jove.com/v/15224 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15229.jpg Antiasthma Drugs: β 2 -Adrenoceptor Agonists Bronchodilators are critical in managing asthma, a chronic respiratory condition characterized by airway constriction due to inflammation and hyper-reactivity. Specifically, bronchodilators ease this constriction by relaxing the bronchial muscles, facilitating easier breathing. One class of bronchodilators includes β2-adrenoceptor agonists. These agents target the β2-adrenoceptors located on bronchial smooth muscle cells. By stimulating these receptors, β2-agonists induce relaxation in these... https://www.jove.com/v/15229 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15230.jpg Antiasthma Drugs: Methylxanthines Theophylline, a member of the methylxanthine class of bronchodilators, has long been used in asthma management. While its exact mechanism of action is not fully understood, it is believed to have multiple effects on various cellular processes. Theophylline is thought to inhibit phosphodiesterase enzymes, increasing intracellular levels of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). This rise in cAMP and cGMP concentrations stimulates cardiac function,... https://www.jove.com/v/15230 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15233.jpg Antiasthma Drugs: Inhaled Corticosteroids and Glucocorticoids Inhaled corticosteroids (ICS) are anti-inflammatory drugs used primarily in treating persistent asthma and providing long-term maintenance. They target the bronchial mucosa, the lining of the airways, to control inflammation, a critical factor in asthma progression and exacerbation. ICS work through a multifaceted mechanism of action. They suppress the inflammatory response caused by the proliferation of TH cells. They also reduce the transcription of the IL-2 gene, which is involved in the... https://www.jove.com/v/15233 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15234.jpg Antiasthma Drugs: Mast Cell Stabilizers and Anti-IgE Drugs Asthma is a chronic respiratory condition for which new therapeutic avenues, including anti-inflammatory drugs like mast cell stabilizers and anti-IgE treatments, continue to be developed. Mast cell stabilizers, such as cromolyn (also known as sodium cromoglycate) and nedocromil (Tilade), are effective drugs in asthma management. These stabilizers hinder histamine release by skillfully obstructing the activation of mast cells and other cellular entities. Notably, they navigate this task without... https://www.jove.com/v/15234 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16383.jpg Inhaled Medications Inhaled medications are crucial for managing chronic obstructive pulmonary disease (COPD) and asthma. They are essential for effective treatment and control, ensuring optimal respiratory health and well-being. Inhaled medication delivers drugs directly to the lungs, providing a rapid onset of action and reducing systemic side effects compared to oral or injectable medications. Three primary types of inhalation devices are used to administer these medications: nebulizers, metered-dose inhalers... https://www.jove.com/v/16383 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55454.jpg Dry Powder and Nebulized Aerosol Inhalation of Pharmaceuticals Delivered to Mice Using a Nose-only Exposure System The inhalation unit described herein can generate, sample for characterization, and uniformly deposit a drug aerosol in the lungs of rodents. This enables the pre-clinical determination of the efficacy and safety of drug doses deposited in the lungs; key data enabling clinical inhaled drug development. https://www.jove.com/v/55454 448 2017-04-06T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66188.jpg Auricular Acupressure as an Adjuvant Treatment for Wheezing in Stable Chronic Obstructive Pulmonary Disease This protocol describes an effective therapy using auricular acupressure to relieve wheezing symptoms in stable chronic obstructive pulmonary disease. https://www.jove.com/v/66188 154 2024-05-10T21:00:00+00:00 JoVE no https://visualize.jove.com/12225583-computational-discovery-of-sense-antisense-transcription-in-the-human-and-mouse-genomes monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11607.jpg Cis-regulatory Sequences Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are... https://www.jove.com/v/11607 122 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58627.jpg Cell Based Assays of SINEUP Non-coding RNAs That Can Specifically Enhance mRNA Translation SINEUPs are synthetic antisense non-coding RNAs, which contain a binding domain (BD) and an effector domain (ED) and up-regulate translation of target mRNA. Here, we describe detection methods for SINEUPs in cultured cell lines, analysis of their translation-promoting activity by Western-blot and a semi-automated high throughput imaging system. https://www.jove.com/v/58627 621 2019-02-01T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67552.jpg Identification of Functionally-Relevant Lentivirus Integration Sites in an Insertional Mutagenesis Cell Library Insertional mutagenesis is an essential tool in forward genetics for identifying functional genomic elements. Here, we describe the Insertion-based Screen for functional Elements and Transcripts (InSET), a method for detecting lentivirus integration sites within a lentivirus-based insertional mutagenesis cell library. https://www.jove.com/v/67552 448 2025-01-10T22:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/69400.jpg A Computational Pipeline for Intergenic/Intragenic Enhancer RNA Quantification in Mouse Embryonic Stem Cells This protocol provides a streamlined computational pipeline for quantifying nascent enhancer transcripts. By integrating chromatin accessibility, chromatin feature, and transcriptional data, it enables accurate detection and strand-specific analysis of enhancer activity in complex intragenic regions, while remaining accessible to researchers without extensive bioinformatics training. https://www.jove.com/v/69400 362 2025-10-28T21:00:00+00:00 JoVE no https://visualize.jove.com/12231243-the-distribution-of-fos-immunoreactivity-in-rat-brain-following-freezing-and-escape-responses-elicited-by-electrical-stimulation-of-the-inferior-colliculus monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/53613.jpg The c-FOS Protein Immunohistological Detection: A Useful Tool As a Marker of Central Pathways Involved in Specific Physiological Responses In Vivo and Ex Vivo Here, we present a protocol based on c-FOS protein immunohistological detection, a classical technique used for the identification of neuronal populations involved in specific physiological responses in vivo and ex vivo. https://www.jove.com/v/53613 344 2016-04-25T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54358.jpg Fluorescence Activated Cell Sorting (FACS) and Gene Expression Analysis of Fos-expressing Neurons from Fresh and Frozen Rat Brain Tissue Here we present a Fluorescence Activated Cell Sorting (FACS) protocol to study molecular alterations in Fos-expressing neuronal ensembles from both fresh and frozen brain tissue. The use of frozen tissue allows FACS isolation of many brain areas over multiple sessions to maximize the use of valuable animal subjects. https://www.jove.com/v/54358 517 2016-08-27T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56299.jpg A Wireless, Bidirectional Interface for In Vivo Recording and Stimulation of Neural Activity in Freely Behaving Rats A wireless, bidirectional system for multi-channel neural recordings and stimulation in freely behaving rats is introduced. The system is light and compact, thus having minimal impact on the animal´s behavioral repertoire. Moreover, this bidirectional system provides a sophisticated tool to assess causal relationships between brain activation patterns and behavior. https://www.jove.com/v/56299 641 2017-11-07T21:00:00+00:00 JoVE no https://visualize.jove.com/12241247-method-for-detecting-the-signature-of-noise-induced-structures-in-spatiotemporal-data-sets monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16100.jpg State Space Representation The frequency-domain technique, commonly used in analyzing and designing feedback control systems, is effective for linear, time-invariant systems. However, it falls short when dealing with nonlinear, time-varying, and multiple-input multiple-output systems. The time-domain or state-space approach addresses these limitations by utilizing state variables to construct simultaneous, first-order differential equations, known as state equations, for an nth-order system. Consider an RLC circuit, a... https://www.jove.com/v/16100 87 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50319.jpg Identification of Disease-related Spatial Covariance Patterns using Neuroimaging Data Multivariate techniques including principal component analysis (PCA) have been used to identify signature patterns of regional change in functional brain images. We have developed an algorithm to identify reproducible network biomarkers for the diagnosis of neurodegenerative disorders, assessment of disease progression, and objective evaluation of treatment effects in patient populations. https://www.jove.com/v/50319 867 2013-06-26T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55311.jpg Microfluidic Platform with Multiplexed Electronic Detection for Spatial Tracking of Particles We demonstrate a microfluidic platform with an integrated surface electrode network that combines resistive pulse sensing (RPS) with code division multiple access (CDMA), to multiplex detection and sizing of particles in multiple microfluidic channels. https://www.jove.com/v/55311 714 2017-03-13T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62790.jpg Probing Structural and Dynamic Properties of Trafficking Subcellular Nanostructures by Spatiotemporal Fluctuation Spectroscopy Imaging-derived mean square displacement (iMSD) analysis is applied to macropinosomes to highlight their intrinsic time-evolving nature in terms of structural and dynamic properties. Macropinosomes are then compared to insulin secretory granules (ISGs) as a reference for subcellular structures with time-invariant average structural/dynamic properties. https://www.jove.com/v/62790 497 2021-08-16T21:00:00+00:00 JoVE no https://visualize.jove.com/12267751-aids-whatve-monkeys-got-to-do-with-it monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3258.jpg Behavioral Assessment of Manual Dexterity in Non-Human Primates As manual dexterity is a prerogative mainly of primates, behavioral tasks have been developed in macaque monkeys. Four reach and grasp prehension tasks, measuring hand manipulation ability and force, allow to establish functional recovery after a lesion of the central nervous system and to test the effect of a treatment. https://www.jove.com/v/3258 960 2011-11-11T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10825.jpg Retrovirus Life Cycles Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the retrovirus to... https://www.jove.com/v/10825 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11572.jpg Retroviruses Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’... https://www.jove.com/v/11572 153 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16319.jpg Sexually Transmitted Infections Sexually transmitted infections (STIs) are diseases transmitted primarily through unsafe sexual interactions. Bacteria, viruses, or parasites cause them and can result in severe health complications if untreated.ChlamydiaThe bacterium Chlamydia trachomatis is responsible for the disease Chlamydia, the most common STI in the United States. This peculiar pathogen requires human cells to reproduce, residing intracellularly. The initial infection often goes unnoticed because it typically does not... https://www.jove.com/v/16319 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/40852/40852_article_thumb_40852.jpg Malaria Malaria pathogenesis in humans reflects a delicate interplay between parasite biology and host response. Clinical illness reflects a host’s immune response to the parasite’s asexual replication cycle, which is often asymptomatic in individuals with partial immunity. From the parasite's perspective, transmission between mosquito and human with minimal host pathology is evolutionarily advantageous. Among the six Plasmodium species infecting humans, P. falciparum and P. vivax dominate in global... https://www.jove.com/v/40852 89 2026-05-20T21:23:29+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40856/40856_article_thumb_40856.jpg Amebiasis Entamoeba histolytica, a protozoan parasite, is responsible for intestinal and extraintestinal amebiasis. Though a significant proportion of infections remain asymptomatic, approximately 50 million individuals annually are estimated to present with clinical disease, resulting in up to 100,000 deaths globally. The disease burden is disproportionately high in regions with lower socioeconomic status, such as parts of India, Africa, Mexico, and Latin America.Etiology and TransmissionThe infective... https://www.jove.com/v/40856 88 2026-05-20T21:29:57+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/41743/41743_article_thumb_41743.jpg Inhibitors of Virion Maturation and Assembly As part of their replication cycle, certain viruses synthesize long precursor proteins called polyproteins within infected host cells. In human immunodeficiency virus (HIV), two major polyproteins are produced: Gag and Gag-Pol. The Gag polyprotein supplies the structural components of the virus, while Gag-Pol includes essential viral enzymes such as reverse transcriptase, integrase, and protease. After synthesis, these polyproteins move to the host cell membrane, where they assemble into an... https://www.jove.com/v/41743 79 2026-05-20T21:38:19+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54881.jpg Analysis of Simian Immunodeficiency Virus-specific CD8 + T-cells in Rhesus Macaques by Peptide-MHC-I Tetramer Staining Here, we present an optimized protocol for enumerating and characterizing rhesus macaque CD8+ T cells against the AIDS virus. This article is useful not only to the field of HIV immunology, but also to other areas of biomedical research where CD8+ T cell responses are known to affect disease outcome. https://www.jove.com/v/54881 385 2016-12-23T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59427.jpg Processing of Bronchoalveolar Lavage Fluid and Matched Blood for Alveolar Macrophage and CD4 + T-cell Immunophenotyping and HIV Reservoir Assessment We describe a method for processing bronchoalveolar lavage fluid and matched peripheral blood from chronically HIV-infected individuals on antiretroviral therapy to assess pulmonary HIV reservoirs. These methods result in the acquisition of highly pure CD4 T cells and alveolar macrophages that may subsequently be used for immunophenotyping and HIV DNA/RNA quantifications by ultrasensitive polymerase chain reaction. https://www.jove.com/v/59427 441 2019-06-23T20:00:00+00:00 JoVE no https://visualize.jove.com/12324492-automated-transport-and-sorting-system-in-a-large-reference-laboratory-part-1-evaluation-of-needs-and-alternatives-and-development-of-a-plan monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11933.jpg Overview of Protein Sorting and Transport Eukaryotic cells have different membrane-bound organelles with distinct protein requirements. The process by which proteins are targeted to a specific organelle is called protein sorting. Protein sorting can be of two types: signal-based sorting and vesicle-based trafficking. In signal-based sorting, specific amino acid sequences called sorting signals target proteins to the proper location inside the cell either via gated transport or by protein translocation. In gated transport, folded... https://www.jove.com/v/11933 105 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51047.jpg Automated, Quantitative Cognitive/Behavioral Screening of Mice: For Genetics, Pharmacology, Animal Cognition and Undergraduate Instruction Fully automated system for measuring physiologically meaningful properties of the mechanisms mediating spatial localization, temporal localization, duration, rate and probability estimation, risk assessment, impulsivity, and the accuracy and precision of memory, in order to assess the effects of genetic and pharmacological manipulations on foundational mechanisms of cognition in mice. https://www.jove.com/v/51047 983 2014-02-27T06:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54703.jpg Automated Robotic Liquid Handling Assembly of Modular DNA Devices Here, an automated workflow to perform modular DNA "device" assembly using a modular cloning DNA assembly method on liquid-handling robots is presented. The protocol uses an intuitive software tool for generating liquid handler picklists for combinatorial DNA device library generation, which we demonstrate using two liquid handling platforms. https://www.jove.com/v/54703 682 2017-12-01T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57393.jpg Optimizing the Use of a Liquid Handling Robot to Conduct a High Throughput Forward Chemical Genetics Screen of Arabidopsis thaliana A high throughput screen of synthetic small molecules was conducted on the model plant species, Arabidopsis thaliana. This protocol, developed for a liquid handling robot, increases the speed of forward chemical genetics screens, accelerating the discovery of novel small molecules affecting plant physiology. https://www.jove.com/v/57393 718 2018-04-30T20:30:00+00:00 JoVE no https://visualize.jove.com/12390055-ibutilide-in-rapid-conversion-of-atrial-flutter-in-octogenarians monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3671.jpg The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation The accompanying video describes a procedure for percutaneous placement of the WATCHMAN Left Atrial Appendage (LAA) Device. The WATCHMAN is a nitinol device designed to be permanently implanted at, or slightly distal to, the opening of the left atrial appendage (LAA) to trap blood clots before they exit the LAA, preventing thromboembolic stroke. https://www.jove.com/v/3671 1413 2012-02-28T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/3818.jpg Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation Catheter ablation is combined with placement of the WATCHMAN Left Atrial Appendage Closure Device to prevent ischemic stroke in a patient with non-valvular atrial fibrillation. https://www.jove.com/v/3818 2013-02-26T19:57:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15030.jpg Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers Adrenergic stimulation generally impacts cardiac rate and rhythm. Specifically, stimulation of the β-adrenoceptors triggers an increase in intracellular calcium ion influx and pacemaker currents, which may cause arrhythmias. Catecholamines like adrenaline also demonstrate β2-adrenoceptor-mediated hypokalemia, impacting cardiac action potential and disrupting the normal cardiac rhythm. Class II antiarrhythmic drugs are β-adrenoceptor antagonists or β-blockers, which indirectly block calcium... https://www.jove.com/v/15030 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15031.jpg Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers Class III antiarrhythmic drugs are a group of medications that can prolong action potentials in the heart. They achieve this by blocking potassium channels or enhancing inward currents from sodium channels. However, these drugs have a unique property of "reverse use-dependence," which is most pronounced at slower heart rates and can lead to torsades de pointes—a specific type of arrhythmia. However, it is essential to note that excessive QT interval prolongation—a measure of the heart's... https://www.jove.com/v/15031 72 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15032.jpg Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers Class IV antiarrhythmic drugs, such as verapamil and diltiazem, block calcium channels. They primarily affect the heart, slowing the conduction in calcium-dependent tissues like the SA and AV nodes. These drugs manage reentrant supraventricular tachycardia (SVT) and reduce ventricular rate in atrial flutter/fibrillation. Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and... https://www.jove.com/v/15032 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15276.jpg Disturbances in Heart Rhythm Arrhythmia or dysrhythmia refers to an abnormal heart rhythm caused by a defect in the heart's conduction system. It can cause the heart to beat irregularly, too quickly, or too slowly, leading to symptoms like chest pain, shortness of breath, and fainting. Factors such as stress, caffeine, alcohol, nicotine, cocaine, certain drugs, congenital defects, diseases, and electrolyte abnormalities can trigger arrhythmias. Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart... https://www.jove.com/v/15276 89 2025-07-29T16:29:05+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17943/17943_article_thumb_17943.jpg Dysrhythmias VI: Management of Dysrhythmias Dysrhythmia management involves a multifaceted approach, incorporating pharmacological treatments, medical procedures, surgical interventions, lifestyle modifications, and patient education.Pharmacological ManagementAntiarrhythmic Drugs:Class I (Sodium Channel Blockers): This class includes quinidine and procainamide, which reduce the speed of impulse conduction in the heart, stabilize the cardiac membrane, and control arrhythmias. Quinidine and procainamide are Class IA agents that prolong the... https://www.jove.com/v/17943 85 2025-06-19T16:37:04+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18437/18437_article_thumb_18437.jpg ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias Arrhythmia is a condition characterized by an irregular heart rhythm, with ECG changes that differ based on its origin and nature. The types of arrhythmias discussed below include atrial, junctional, and ventricular arrhythmias.Atrial ArrhythmiasPremature Atrial Complexes (PACs): PACs are early atrial beats caused by stress, caffeine, alcohol, electrolyte imbalances, hypoxia, hyperthyroidism, or certain medications (e.g., bronchodilators and decongestants). The ECG shows early P waves with an... https://www.jove.com/v/18437 85 2025-06-19T16:15:27+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67958.jpg Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System This study introduces a novel approach for real-time cardiac mapping using a noninvasive, imageless electrocardiographic imaging system. This system enables the acquisition of electrophysiological cardiac maps without requiring pre-procedural computed tomography or magnetic resonance imaging scans, enabling efficient guidance for cardiac procedures such as ablation and cardiac resynchronization therapy implants. https://www.jove.com/v/67958 617 2025-04-11T21:20:00+00:00 JoVE no https://visualize.jove.com/12451795-computer-assisted-system-for-analysis-of-heart-rate-variability-in-clinical-studies monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13286.jpg Pulse rhythm Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding. Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle... https://www.jove.com/v/13286 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13315.jpg Assessment of blood pressure in brachial artery(two-step method) Measuring blood pressure is a fundamental skill in healthcare that aids in diagnosing and monitoring hypertension and other cardiovascular conditions. An aneroid sphygmomanometer, commonly used in clinical settings, offers a manual and precise method for blood pressure measurement. The technique for using this instrument involves specific steps that must be carefully executed to ensure accuracy. The following detailed description outlines a two-step technique for assessing blood pressure using... https://www.jove.com/v/13315 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15273.jpg Electrocardiogram An electrocardiogram (ECG or EKG) is a critical diagnostic tool that records the electrical signals produced by the heart during each heartbeat. This recording is achieved through electrodes placed strategically on the arms, legs, and chest. The electrocardiograph amplifies these signals and produces 12 distinct tracings, offering a comprehensive understanding of the heart's electrical activity. Three major waveforms are present in a typical ECG recording: the P wave, the QRS complex, and the T... https://www.jove.com/v/15273 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15275.jpg Correlation between ECG and Cardiac Cycle The electrical signals recorded on an electrocardiogram (ECG) occur before the mechanical processes of contraction and relaxation during the cardiac cycle. A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before... https://www.jove.com/v/15275 85 2025-05-15T16:16:28+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17874.jpg Blood Studies for Cardiovascular System I: Cardiac Biomarkers Cardiac biomarkers are enzymes, proteins, and hormones released into the blood when cardiac cells are injured. They are powerful tools for triaging. The essential diagnostic tools for detecting myocardial necrosis and monitoring individuals suspected of having acute coronary syndrome (ACS) include: Troponins Troponins, particularly cardiac troponins I and T, are the most precise and sensitive markers of myocardial injury. They are detectable within 4-6 hours of myocardial injury and remain... https://www.jove.com/v/17874 80 JoVE no https://cloudfront.jove.com/files/ftp_upload/17887/17887_article_thumb_17887.jpg Holter Monitor: 24-Hour Monitoring Holter monitoring is a continuous electrocardiography (ECG) recording that tracks the heart's electrical activity over an extended period, generally 24 to 48 hours. This noninvasive diagnostic tool detects irregular heart rhythms that may not be captured during a standard ECG performed in a clinical setting.DeviceThe Holter monitor is a portable, small device connected to several electrodes on the patient's chest. These electrodes detect the heart's electrical signals and transmit them to the... https://www.jove.com/v/17887 83 2025-06-19T16:09:27+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50124.jpg A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis Continuous 12-lead electrocardiographic (ECG) monitoring can identify transient myocardial ischemia, even when asymptomatic, among patients with suspected acute coronary syndrome (ACS). In this article we describe our method for initiating patient monitoring using a Holter device, downloading the ECG data for off-line analysis, and how to utilize the ECG software to identify transient ischemia. https://www.jove.com/v/50124 1091 2012-12-28T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59230.jpg Calculating Heart Rate Variability from ECG Data from Youth with Cerebral Palsy During Active Video Game Sessions This protocol describes a method for calculating Heart Rate Variability (HRV) from electrocardiogram (ECG) waveforms. Waveforms from continuous heart rate (HR) recordings during active video game (AVG) sessions were used to measure the aerobic performance of youth with cerebral palsy (CP). https://www.jove.com/v/59230 492 2019-06-05T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67222.jpg Software for Analysis of Heart Rate and Blood Pressure Time-series Data from the Valsalva Maneuver The ValsalvaAnalyzer software includes functions to analyze continuous beat-to-beat electrocardiogram and blood pressure (BP) measurements recorded during the Valsalva maneuver (VM). The computed clinical biomarkers and estimated model outputs provide insight into sympathetic and parasympathetic regulation of heart rate and BP during the VM. https://www.jove.com/v/67222 868 2025-06-27T19:40:00+00:00 JoVE no https://visualize.jove.com/12455744-real-time-pulse-oximetry-artifact-annotation-on-computerized-anaesthetic-records monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13263.jpg Guidelines For Measuring Vital Signs Following these guidelines can help nurses accurately measure vital signs, assess changes in patient conditions, and provide timely treatment when necessary. Adhering closely to the guidelines ensures the accuracy and reliability of the results. Before taking a patient's vital signs, a nurse would consider and assess the patient's comfort level and ensure appropriate equipment is available. • Patient Comfort Level: Patients must be relaxed and comfortable before vital sign measurement. https://www.jove.com/v/13263 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13286.jpg Pulse rhythm Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding. Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle... https://www.jove.com/v/13286 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13293.jpg Assessment of apical radial pulse Apical-Radial (A-R) Pulse Assessment The A-R pulse assessment involves simultaneous evaluation of the apical and radial pulses. When the apical and radial pulse rates vary, this assessment helps identify a pulse deficit. Pre-Procedural Preparation Equipment Preparation: Gather all necessary supplies, including a watch with a second hand (for accurate counting), a stethoscope, antiseptic wipes, and a vital signs flow sheet. Patient Interaction: • Identification: Confirm the patient's... https://www.jove.com/v/13293 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13303.jpg Special considerations while measuring oxygen saturation Assessing respiratory rate concurrently with pulse measurement is fundamental to patient care, providing valuable insights into the patient's respiratory function. The normal breathing rate for an adult usually falls within a normal range of 12 to 20 breaths per minute. Abnormal respiratory rates can signal underlying health conditions or the need for immediate intervention. Ensuring accuracy in vital sign recordings while prioritizing patient comfort and minimizing anxiety is important. <br... https://www.jove.com/v/13303 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15299.jpg Pulse When the heart pumps blood out, arterial elastic fibers play a crucial role in sustaining a high-pressure gradient. They expand to accommodate the received blood and then recoil - a process known as the pulse that can be either manually palpated or electronically quantified. Despite a reduction in its effect with increased distance from the heart, elements of the pulse's systolic and diastolic components persist, observable even at the arteriole level. The pulse serves as a clinical indicator... https://www.jove.com/v/15299 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16381.jpg Pulse Oximetry Pulse oximetry, or SpO2, is a non-invasive method for continuously monitoring arterial oxygen saturation (SaO2). This procedure involves attaching a probe or sensor to the patient's fingertip, forehead, earlobe, or nose bridge. The sensor works by detecting changes in oxygen saturation levels through light signals generated by the oximeter and reflected by the pulsing blood under the probe. Purpose Average SpO2 values are greater than 95%. If the readings fall below 90%, it indicates that... https://www.jove.com/v/16381 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61311.jpg Use of an Integrated Low-Flow Anesthetic Vaporizer, Ventilator, and Physiological Monitoring System for Rodents Here, we present a protocol to safely and effectively administer anesthetic gas to mice using a digital, low flow anesthesia system with integrated ventilator and physiological monitoring modules. https://www.jove.com/v/61311 417 2020-07-09T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65963.jpg A Porcine Model of Acute Respiratory Failure with a Continuous Infusion of Oleic Acid Infusing oleic acid continuously into the pulmonary artery of an anesthetized adult pig induces acute respiratory failure, enabling controlled experimentation during acute respiratory decompensation. https://www.jove.com/v/65963 250 2024-03-08T21:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66062.jpg Non-Invasive Monitoring of Microvascular Oxygenation and Reactive Hyperemia using Hybrid, Near-Infrared Diffuse Optical Spectroscopy for Critical Care We describe a protocol to non-invasively and continuously measure absolute microvascular blood flow index and blood oxygen saturation using a multi-modal device based on near-infrared diffuse optics. We then evaluate the metabolic rate of oxygen consumption and reactive hyperemia utilizing a vascular occlusion test. https://www.jove.com/v/66062 868 2024-05-10T20:40:00+00:00 JoVE no https://visualize.jove.com/12455779-a-coronary-active-perfusion-system-for-off-pump-coronary-artery-bypass-advantage-over-passive-perfusion-regarding-the-physiology-of-the-coronary-artery monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13300.jpg Assessment of Diffusion and Perfusion Understanding and evaluating diffusion and perfusion is critical in assessing a patient's respiratory and circulatory health. These processes play key roles in maintaining the body's internal environment, ensuring that tissues receive adequate oxygen while waste products are efficiently removed. The Role of Diffusion in Respiration Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration. In the respiratory system, this principle... https://www.jove.com/v/13300 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15033.jpg Pathophysiology of Cardiac Performance Typical heart performance is influenced by heart rate, rhythm, myocardial contraction, and metabolism or blood flow. The cardiac muscle exhibits distinct electrophysiological features, including pacemaker activity and calcium channel control, which play a vital role in the heart's response to various drugs. The autonomic nervous system, comprising the sympathetic and parasympathetic branches, regulates heart rate. Sympathetic activation increases heart rate, while parasympathetic activation... https://www.jove.com/v/15033 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15271.jpg Coronary Circulation The heart, an organ critical to survival, gets nourishment not from the blood it pumps but from a separate circulation system known as coronary circulation. This is the shortest circulation in the body and is responsible for supplying the heart with the nutrients it needs to function effectively. Coronary circulation begins at the base of the aorta, where two main arteries arise—the left and right coronary arteries. These arteries encircle the heart in the coronary sulcus and supply the... https://www.jove.com/v/15271 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17862.jpg Physiology of the Heart: The Cardiac Cycle The cardiac cycle describes the events from one heartbeat to the next. It includes three main phases: diastole, atrial systole, and ventricular systole, all driven by changes in chamber pressures and the function of heart valves. Diastole: The Relaxation Phase During diastole, all four heart chambers relax. The atrioventricular (AV) valves open, and the semilunar valves close. This phase sees the lowest chamber pressures, promoting ventricular filling. Venous blood enters the heart through the... https://www.jove.com/v/17862 78 JoVE no https://cloudfront.jove.com/files/ftp_upload/17927/17927_article_thumb_17927.jpg Coronary Artery Disease V: Interprofessional Care Interprofessional care for coronary artery disease includes pharmacological therapy and revascularization procedures.Pharmacological therapy for Coronary Artery Disease (CAD) aims to manage symptoms, prevent complications, and improve patient outcomes through various classes of medications:Antiplatelet Agents:Aspirin and Clopidogrel: These medications inhibit platelet aggregation, preventing blood clots, which is crucial for avoiding heart attacks and strokes. Doctors often prescribe these... https://www.jove.com/v/17927 87 2025-06-19T15:03:16+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65553.jpg Surgical Porcine Model of Chronic Myocardial Ischemia Treated by Exosome-laden Collagen Patch and Off-pump Coronary Artery Bypass Graft This study presents a surgical porcine model of chronic myocardial ischemia due to progressive coronary artery stenosis, resulting in impaired cardiac function without infarction. Following ischemia, animals undergo off-pump coronary artery bypass graft with epicardial placement of stem cells-derived exosomes-laden collagen patch. This adjunctive therapy improves myocardial function and recovery. https://www.jove.com/v/65553 325 2023-09-15T20:40:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66567.jpg Coronary Angiography During Ex-Situ Heart Perfusion in a Porcine Model Screening for coronary artery disease could increase the procurement of donor hearts with extended criteria. A protocol for performing reproducible coronary angiography during ex-situ heart perfusion is described herein in a porcine model. https://www.jove.com/v/66567 385 2024-07-12T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66624.jpg Cardiac Loading using Passive Left Atrial Pressurization and Passive Afterload for Graft Assessment The protocol describes a porcine ex vivo heart perfusion system in which direct loading of the left ventricle may serve as an assessment technique for graft health while simultaneously providing a holistic evaluation of graft function. A discussion of the system design and possible assessment metrics is also provided. https://www.jove.com/v/66624 529 2024-08-02T20:30:00+00:00 JoVE no https://visualize.jove.com/12456043-analysis-of-allogeneic-versus-xenogeneic-auxiliary-organ-perfusion-in-liver-failure-reveals-superior-efficacy-of-human-livers monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/50567.jpg Steps for the Autologous Ex vivo Perfused Porcine Liver-kidney Experiment Study of the animal organ physiology can be achieved by performing an experimental ex vivo perfusion system. The addition of a porcine kidney, as a homeostatic organ to our previously developed ex vivo liver perfusion model can be a principal step to achieve a better physiological environment. https://www.jove.com/v/50567 615 2013-12-18T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52777.jpg Functional Human Liver Preservation and Recovery by Means of Subnormothermic Machine Perfusion We describe a method of ex vivo machine perfusion of human liver grafts at subnormothermic temperature (21 °C). https://www.jove.com/v/52777 534 2015-04-27T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66516.jpg Heterotopic Auxiliary Whole Liver Rat Transplant Model Utilizing a Hepaticoureterostomy for Allograft Rejection Studies The rat heterotopic auxiliary liver transplant protocol described here offers a practical investigational tool for exploring mechanisms of hepatic allograft rejection. This model helps to alleviate the surgical hurdles and animal stress of orthotopic liver transplantation in rats. https://www.jove.com/v/66516 685 2024-03-08T22:30:00+00:00 JoVE no https://visualize.jove.com/12463894-characteristics-and-override-rates-of-order-checks-in-a-practitioner-order-entry-system monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11056.jpg Obedience According to obedience research, we may harm others under the forceful pressures of an authority figure (Milgram, 1974). How about if the inappropriate orders were delivered with less force? The increasing interdependence between nurses and physicians compelled Hofling and his colleagues to explore nurses’ reactions to a potentially harmful medical request made by the perceived authority figure, the doctor (Hofling, Brotzman, Dalrymple, Graves, & Pierce, 1966). In this situation, obedience... https://www.jove.com/v/11056 68 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11376.jpg Determining Order of Reaction Rate laws describe the relationship between the rate of a chemical reaction and the concentration of its reactants. In a rate law, the rate constant k and the reaction orders are determined experimentally by observing how the rate of reaction changes as the concentrations of the reactants are changed. A common experimental approach to the determination of rate laws is the method of initial rates. This method involves measuring reaction rates for multiple experimental trials carried out using... https://www.jove.com/v/11376 173 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11697.jpg Rate Law and Reaction Order The rate of a reaction is affected by the concentrations of reactants. Rate laws (differential rate laws) or rate equations are mathematical expressions describing the relationship between the rate of a chemical reaction and the concentration of its reactants. For example, in a generic reaction aA + bB ⟶ products, where a and b are stoichiometric coefficients, the rate law can be written as: rate = k[A]m[B]n [A] and [B] represent the molar concentrations of reactants, and k is the rate... https://www.jove.com/v/11697 153 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14113.jpg Methods of Documentation V: CBE Charting by Exception, or CBE, is a method of documentation used in healthcare, particularly in nursing, that focuses on documenting only significant or abnormal findings rather than recording every detail. This approach aims to streamline the documentation process, improve efficiency, and ensure that healthcare providers can quickly identify deviations from normalcy in patient assessments. In CBE, healthcare professionals establish predefined standards of practice that define what constitutes... https://www.jove.com/v/14113 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14122.jpg Types of Reports III: Telephone and Verbal Reports Telephone and Verbal Reports in healthcare settings are two communication methods for conveying therapeutic instructions from healthcare providers to nurses or other healthcare staff. Here's an overview of each type: Telephone Orders Usage: Telephone orders are used when a healthcare provider needs to communicate therapeutic instructions to a nurse or other staff over the phone. It often happens when the provider cannot be physically present. Confirmation and Documentation: Oral confirmation... https://www.jove.com/v/14122 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16469.jpg Fundamental Mathematical Principles in Pharmacokinetics: Rate and Order of Reaction In pharmacokinetics, the rates and order of reactions play a crucial role in understanding how the body processes drugs and help us comprehend drug absorption, distribution, metabolism, and elimination. A critical concept in pharmacokinetics is the rate constant, which quantifies the speed of a reaction. It provides valuable information about the kinetics of drug elimination. The rate constant allows us to determine the rate at which drugs are eliminated from the body. Pharmacokinetic reactions... https://www.jove.com/v/16469 75 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56175.jpg Failure of Cleaning Verification in Pharmaceutical Industry Due to Uncleanliness of Stainless Steel Surface The lack of a well-defined procedure that consistently cleaned coupon surfaces was identified as the major contributor to low and variable recoveries in cleaning verification. This manuscript describes the correct protocol of cleaning stainless steel coupons. https://www.jove.com/v/56175 420 2017-08-11T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58132.jpg Hydra, a Computer-Based Platform for Aiding Clinicians in Cardiovascular Analysis and Diagnosis This article presents a protocol based on Hydra — a web-based system for clinical decision support that integrates a full and detailed set of functionalities and services required by physicians for complete cardiovascular analysis, risk assessment, early diagnosis, treatment, and monitoring over time. https://www.jove.com/v/58132 471 2018-09-26T20:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63243.jpg Conducting Respiratory Oscillometry in an Outpatient Setting We demonstrate a standard operating protocol to conduct respiratory oscillometry, highlighting key quality control and assurance procedures. https://www.jove.com/v/63243 889 2022-04-08T21:00:00+00:00 JoVE no https://visualize.jove.com/12493596-scale-invariant-fluctuations-of-the-dynamical-synchronization-in-human-brain-electrical-activity monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14942.jpg Brain Waves Brain waves are electrical signals generated by the neurons in the brain, which are regularly monitored to measure mental activities. Brain waves and their frequency ranges can be measured using an electroencephalogram or EEG. There are four main types of brain waves, each with distinct characteristics: • Alpha Waves – Alpha brain waves, between 8 and 13 Hz ( Hertz), occur when a person is relaxed with eyes closed. The alpha waves then disappear when one is concentrating on specific tasks. <br... https://www.jove.com/v/14942 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62777.jpg Inter-Brain Synchrony in Open-Ended Collaborative Learning: An fNIRS-Hyperscanning Study The protocol for conducting fNIRS hyperscanning experiments on collaborative learning dyads in a naturalistic learning environment is outlined. Further, a pipeline to analyze the Inter-Brain Synchrony (IBS) of oxygenated hemoglobin (Oxy-Hb) signals is presented. https://www.jove.com/v/62777 284 2021-07-21T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62801.jpg How to Calculate and Validate Inter-brain Synchronization in a fNIRS Hyperscanning Study The dynamics between coupled brains of individuals have been increasingly represented by inter-brain synchronization (IBS) when they coordinate with each other, mostly using simultaneous-recording signals of brains (namely hyperscanning) with fNIRS. In fNIRS hyperscanning studies, IBS has been commonly assessed through the wavelet transform coherence (WTC) method because of its advantage on expanding time series into time-frequency space where oscillations can be seen in a highly intuitive way. https://www.jove.com/v/62801 333 2021-09-08T21:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65347.jpg New Framework for Understanding Cross-Brain Coherence in Functional Near-Infrared Spectroscopy (fNIRS) Hyperscanning Studies Wavelet transform coherence (WTC) is a common methodology for assessing the coupling between signals that is used in functional near-infrared spectroscopy (fNIRS) hyperscanning studies. A toolbox for assessing the directionality of the signal interaction is presented in this work. https://www.jove.com/v/65347 359 2023-10-06T21:15:00+00:00 JoVE no https://visualize.jove.com/12494609-impact-of-fusion-avoidance-on-performance-of-the-automatic-threshold-tracking-feature-in-dual-chamber-pacemakers-a-multicenter-prospective-randomized-study monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3750.jpg A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation Dual-chamber implantable cardioverter-defibrillators (ICDs) may improve detection of atrial fibrillation as well as differentiation of tachycardias. However, this advantage is undermined by complications associated with the second electrode, which is required in conventional dual chamber devices. Therefore, BIOTRONIK has developed a new electrode called the LinoxSMART S DX that, when used in conjunction with the Lumax DX ICD, offers dual-chamber detection without the risks associated with the... https://www.jove.com/v/3750 1000 2012-02-28T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52606.jpg Non-fluoroscopic Catheter Tracking for Fluoroscopy Reduction in Interventional Electrophysiology Radiation exposure is an underestimated risk in complex ablation procedures. Here, we describe a protocol to significantly decrease fluoroscopy time and dosage for both the patient and the lab staff by using a novel non-fluoroscopic catheter visualization system. https://www.jove.com/v/52606 646 2015-05-26T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63094.jpg Sterile Pericarditis in Aachener Minipigs As a Model for Atrial Myopathy and Atrial Fibrillation We describe a sterile pericarditis model in minipigs to study atrial myopathy and atrial fibrillation (AF). We present surgical and anesthetic techniques, strategies for vascular access, and a protocol to study the inducibility of AF. https://www.jove.com/v/63094 536 2021-09-24T22:00:00+00:00 JoVE no https://visualize.jove.com/12505866-increased-cellular-activity-in-rat-insular-cortex-after-water-and-salt-ingestion-induced-by-fluid-depletion monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16255.jpg Reabsorption and Secretion in the DCT and Collecting Duct The early phase of the DCT manages the reabsorption of approximately 10-15% of filtered water, 5–10% of filtered sodium, and 5–10% of filtered chloride. This process is facilitated by Na+–Cl− symporters in apical membranes and sodium-potassium pumps, as well as Cl− leakage channels in basolateral membranes. The early DCT also stands out as a site where parathyroid hormone (PTH) stimulates calcium reabsorption, depending on the body's requirements. The distal part of the DCT, along with the... https://www.jove.com/v/16255 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16269.jpg Regulation of Water Intake Osmolality refers to the number of solute particles per kilogram of solvent in a solution. Plasma osmolality specifically indicates the total number of solute particles per kilogram of water in blood plasma. This value reflects the body's hydration status and is tightly regulated through mechanisms controlling water intake and output. While water consumption is a conscious decision, the body has intrinsic regulatory systems to maintain fluid balance. Dehydration, a state of water deficit... https://www.jove.com/v/16269 85 JoVE no https://cloudfront.jove.com/files/ftp_upload/40887/40887_article_thumb_40887.jpg Diabetes Insipidus II: Pathophysiology Normally, water balance is maintained through three interconnected mechanisms: the hypothalamic thirst center, the synthesis and release of antidiuretic hormone (ADH, or vasopressin), and the kidneys' responsiveness to this hormone. ADH is synthesized in the hypothalamus, released from the posterior pituitary, and acts on the distal nephron, allowing water reabsorption and concentrated urine production.Diabetes Insipidus and Its TypesIn diabetes insipidus (DI), this regulatory system is... https://www.jove.com/v/40887 82 2026-04-13T21:37:51+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50267.jpg A Model of Chronic Nutrient Infusion in the Rat A protocol for chronic infusions of glucose and Intralipid in rats is described. This model can be used to study the impact of nutrient excess on organ function and physiological parameters. https://www.jove.com/v/50267 498 2013-08-14T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53897.jpg Simultaneous Detection of c-Fos Activation from Mesolimbic and Mesocortical Dopamine Reward Sites Following Naive Sugar and Fat Ingestion in Rats The goal of this study is to identify reward-related distributed brain networks by delineating a reliable immunohistological technique using cellular c-fos activation to measure simultaneous changes in dopamine pathways and terminal sites after novel ingestion of fat and sugar in rats. https://www.jove.com/v/53897 487 2016-08-24T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65902.jpg Real-time Analysis of Gut-brain Neural Communication: Cortex wide Calcium Dynamics in Response to Intestinal Glucose Stimulation Gut-brain communication, facilitated by the vagus nerve, is crucial for communication between the gastrointestinal endocrine system and the brain. However, whether intragastric glucose injection can change cortical activity is still not understood. Here, we offer a comprehensive protocol to observe changes in cortical activity after glucose injection into the duodenum. https://www.jove.com/v/65902 449 2023-12-29T21:30:00+00:00 JoVE no https://visualize.jove.com/12514804-alphavirus-cdna-based-expression-vectors-effects-of-rna-transcription-and-nuclear-export monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3702.jpg In vitro Transcription and Capping of Gaussia Luciferase mRNA Followed by HeLa Cell Transfection This method describes high yield in vitro synthesis of both capped and uncapped mRNA from a linearized plasmid containing the Gaussia luciferase (GLuc) gene. The RNA is purified and a fraction of the uncapped RNA is enzymatically capped using the Vaccinia virus capping enzyme. In the final step, the mRNA is transfected into HeLa cells and cell culture supernatants are assayed for luciferase activity. https://www.jove.com/v/3702 535 2012-03-26T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11589.jpg Nuclear Export of mRNA Before mRNAs are exported to the cytoplasm, it is crucial to check each mRNA for structural and functional integrity. Eukaryotic cells use several different mechanisms, collectively known as mRNA surveillance, to look for irregularities in mRNAs. Irregular or aberrant mRNA are rapidly degraded by various enzymes. If a defective mRNA escapes the surveillance, it would be translated into a protein which would either be non-functional or not function properly. One of the primary irregularities in... https://www.jove.com/v/11589 151 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11624.jpg Regulated mRNA Transport In eukaryotes, transcription and translation are compartmentalized; an mRNA is first synthesized in the nucleus and then selectively transported to the cytoplasm for protein synthesis. Before transport, a pre-mRNA undergoes several steps of post-transcriptional modifications including splicing, 5' capping, and the addition of a poly-adenine tail. Various proteins bind to the pre-mRNA during these modifications. The mRNA transport takes place with the help of multiple proteins playing specific... https://www.jove.com/v/11624 142 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11625.jpg Leaky Scanning During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R stands for... https://www.jove.com/v/11625 148 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11937.jpg Nuclear Export The nucleus restricts several proteins within and allows others to pass. The restricted proteins possess a nuclear retention sequence or NRS, anchoring them to the nuclear lamins and preventing their transport to the cytosol. The non-restricted proteins, after their synthesis, are transported to their site of action, such as the cytosol or other organelles, with the help of nuclear export signals or NES. NES are of three types- the canonical 10-residue long leucine-rich signal and other... https://www.jove.com/v/11937 102 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11589.jpg Nuclear Export of mRNA Before mRNAs are exported to the cytoplasm, it is crucial to check each mRNA for structural and functional integrity. Eukaryotic cells use several different mechanisms, collectively known as mRNA surveillance, to look for irregularities in mRNAs. Irregular or aberrant mRNA are rapidly degraded by various enzymes. If a defective mRNA escapes the surveillance, it would be translated into a protein which would either be non-functional or not function properly. One of the primary irregularities in... https://www.jove.com/v/12568 151 JoVE no https://cloudfront.jove.com/files/ftp_upload/19592/19592_article_thumb_19592.jpg Viruses with RNA Genomes RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. This classification dictates how they exploit host cellular machinery for protein synthesis and replication. Some RNA viruses also utilize reverse transcription as part of their life cycle, further diversifying their replication strategies.Positive-Strand RNA VirusesPositive-strand RNA viruses have genomes that function directly as messenger... https://www.jove.com/v/19592 89 2025-06-12T16:30:23+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50830.jpg Rescue of Recombinant Newcastle Disease Virus from cDNA Newcastle disease virus (NDV) has been extensively studied in the last few years in order to develop new vectors for vaccination and therapy, among others. These studies have been possible due to techniques to rescue recombinant virus from cDNA, such as those we describe here. https://www.jove.com/v/50830 655 2013-10-12T06:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65572.jpg Transgene Expression in Cultured Cells Using Unpurified Recombinant Adeno-Associated Viral Vectors Recombinant adeno-associated virus (rAAV) is widely used for clinical and preclinical gene delivery. An underappreciated use for rAAVs is the robust transduction of cultured cells without the need for purification. For researchers new to rAAV, we provide a protocol for transgene cassette cloning, crude vector production, and cell culture transduction. https://www.jove.com/v/65572 401 2023-10-20T21:20:00+00:00 JoVE no https://visualize.jove.com/12514809-pattern-identification-and-classification-in-gene-expression-data-using-an-autoassociative-neural-network-model monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/63110.jpg Classification of Neural Stem Cell Activation State In Vitro Using Autofluorescence This protocol describes strategies to identify and enrich for cell-state in primary adult mouse neural stem cell cultures by autofluorescence imaging using i) a confocal microscope, ii) a fluorescent activated cell sorter to perform intensity imaging, or iii) a multiphoton microscope to perform fluorescence lifetime imaging. https://www.jove.com/v/63110 416 2024-04-12T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65910.jpg DeepOmicsAE: Representing Signaling Modules in Alzheimer's Disease with Deep Learning Analysis of Proteomics, Metabolomics, and Clinical Data DeepOmicsAE is a workflow centered on the application of a deep learning method (i.e., an autoencoder) to reduce the dimensionality of multi-omics data, providing a foundation for predictive models and signaling modules representing multiple layers of omics data. https://www.jove.com/v/65910 587 2023-12-15T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66030.jpg Generating the Transcriptional Regulation View of Transcriptomic Features for Prediction Task and Dark Biomarker Detection on Small Datasets Here, we introduce a protocol for converting transcriptomic data into a mqTrans view, enabling the identification of dark biomarkers. While not differentially expressed in conventional transcriptomic analyses, these biomarkers exhibit differential expression in the mqTrans view. The approach serves as a complementary technique to traditional methods, unveiling previously overlooked biomarkers. https://www.jove.com/v/66030 217 2024-03-01T21:50:00+00:00 JoVE no https://visualize.jove.com/12520442-modern-stationary-phases-for-ion-chromatography monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12266.jpg Chromatography: Introduction Chromatography is a technique used to separate compounds based on differences of partitioning between two phases, the stationary phase and the mobile phase. The phase in which the compounds linger or on which the compounds adsorb is called the stationary phase, whereas the mobile phase is the solvent that carries the solutes to be analyzed. In traditional column chromatography, the mixture flows through the stationary phase, and the compounds partition between the stationary and mobile phases... https://www.jove.com/v/12266 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14625.jpg Ion Exchange Ion exchange chromatography separates charged molecules from a solution by reversibly exchanging them with mobile, or 'active', ions associated with the oppositely charged stationary phase. This method can be used to separate ions, soften and deionize water, and purify solutions. The polymers comprising the ion-exchange column are high-molecular-weight and chemically stable polymers, crosslinked to be porous and essentially insoluble. They are also functionalized with either acidic or basic... https://www.jove.com/v/14625 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14780.jpg Chromatographic Methods: Classification Chromatographic techniques are classified in three ways: the classification is based on the physical state of the stationary and mobile phases, how the mobile phase and the stationary phase contact each other, or through the chemical or physical processes that isolate the components of the sample. Typically, the mobile phase is either a liquid or gas, while the stationary phase is either a solid or a liquid layer applied to a solid surface. Chromatographic techniques are typically named by... https://www.jove.com/v/14780 72 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14788.jpg Gas Chromatography: Types of Columns and Stationary Phases Gas chromatography (GC) relies on stationary phases to separate and analyze components in a sample. There are two main types of stationary phases: liquid and solid. Liquid stationary phases are non-volatile, thermally stable, and chemically inert liquids coated onto the column. Solid stationary phases are particles of adsorbent material, such as silica gel or molecular sieves. For an analyte to remain on the column for a sufficient amount of time, it must exhibit some level of compatibility (or... https://www.jove.com/v/14788 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14793.jpg High-Performance Liquid Chromatography: Introduction High-performance liquid chromatography(HPLC), formerly referred to as High-pressure liquid chromatography, is a powerful technique used to separate, identify, and quantify components in complex mixtures. The term "high pressure" refers to using high pressure to push the liquid mobile phase through the tightly packed columns. In HPLC, two phases play a critical role in the separation process: Mobile Phase: This is a liquid solvent that flows through the system, carrying the sample with it. The... https://www.jove.com/v/14793 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14797.jpg Ion-Exchange Chromatography Ion-exchange chromatography, or IEC, is a technique for separating ions based on their affinity for the stationary phase. The stationary phase is a cross-linked polymer resin with covalently attached ionic functional groups. The functional groups can be either positively charged (cation exchangers) or negatively charged (anion exchangers). A cation exchanger consists of a polymeric anion and active cations, while an anion exchanger is a polymeric cation with active anions. The choice of... https://www.jove.com/v/14797 69 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60946.jpg Using a Chemical Biopsy for Graft Quality Assessment The protocol presents utilization of the chemical biopsy approach followed by comprehensive metabolomic and lipidomic analysis for quality assessment of kidney grafts allocated for transplantation. https://www.jove.com/v/60946 300 2020-06-17T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63451.jpg Using a Cyclic Ion Mobility Spectrometer for Tandem Ion Mobility Experiments Ion mobility spectrometry (IMS) is an interesting complement to mass spectrometry for the characterization of biomolecules, notably because it is sensitive to isomerism. This protocol describes a tandem IMS (IMS/IMS) experiment, which allows the isolation of a molecule and the generation of the mobility profiles of its fragments. https://www.jove.com/v/63451 520 2022-01-20T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67484.jpg Detection of Regulated Ergot Alkaloids in Food Matrices by Liquid Chromatography-Trapped Ion Mobility Spectrometry-Time-of-Flight Mass Spectrometry This protocol presents a validated liquid chromatography-ion mobility-high resolution mass spectrometry method to determine the presence of ergot alkaloids in food in compliance with the recently released Commission Regulation (EU) 2023/915. https://www.jove.com/v/67484 536 2024-11-22T22:50:00+00:00 JoVE no https://visualize.jove.com/12520835-intravenous-adrenaline-or-vasopressin-in-sudden-cardiac-arrest-a-literature-review monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14473.jpg Adrenergic Agonists: Therapeutic Uses Adrenergic agonists have diverse therapeutic uses across various medical conditions and emergencies. Emergency and Intensive Care Unit (ICU) applications: Pressor agents increase blood pressure, heart rate, and contractility in shock and organ failure situations. Dopamine can induce vasodilation and stimulate adrenoceptors. Endogenous catecholamines are effective in treating cardiogenic shock. α2-agonists like clonidine can reverse anesthesia-induced hypertension. Allergies and anaphylaxis:... https://www.jove.com/v/14473 90 JoVE no https://cloudfront.jove.com/files/ftp_upload/17945/17945_article_thumb_17945.jpg Introduction Cardiac Emergencies Cardiac emergencies are critical situations involving the heart that require immediate medical intervention to prevent severe complications or death. These emergencies often arise from underlying heart conditions that impair the heart's ability to function correctly.Types of Cardiac EmergenciesThe most common types of cardiac emergencies include Acute Coronary Syndrome (ACS), myocardial infarction (MI), cardiac arrest, and heart failure.Acute Coronary Syndrome (ACS)Acute Coronary Syndrome (ACS)... https://www.jove.com/v/17945 90 2025-11-18T18:20:28+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17946/17946_article_thumb_17946.jpg Cardiopulmonary Resuscitation I: Adult Cardiopulmonary resuscitation, or CPR, is a life-saving emergency procedure performed when a person's heart has stopped beating or they are no longer breathing. The foundation of CPR is Basic Life Support (BLS), which focuses on the early recognition of cardiac arrest, the immediate start of high-quality chest compressions, and the timely use of an automated external defibrillator (AED).Assessing Responsiveness and Checking the Carotid PulseWhen approaching an unresponsive person, first ensure... https://www.jove.com/v/17946 81 2025-08-11T17:00:30+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17948/17948_article_thumb_17948.jpg Cardiopulmonary Resuscitation III: AED Use Introduction to AEDAn Automated External Defibrillator (AED) is a portable medical device that analyzes the heart's rhythm and, if necessary, delivers an electrical shock to help the heart re-establish an effective rhythm during sudden cardiac arrest (SCA). SCA occurs when the heart suddenly and unexpectedly stops beating, leading to a loss of blood flow to the brain and other vital organs. In such emergencies, time is of the essence, and using an AED, combined with Cardiopulmonary... https://www.jove.com/v/17948 83 2025-06-19T16:38:36+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17949/17949_article_thumb_17949.jpg Cardiopulmonary Resuscitation IV: Pharmacological Management Pharmacologic intervention is crucial in treating cardiac arrest patients during ACLS or Advanced Cardiovascular Life Support. The ACLS algorithms guide the administration of specific drugs based on the patient's cardiac arrest rhythm, which includes pulseless ventricular tachycardia (VT), ventricular fibrillation (VF), asystole, and pulseless electrical activity (PEA).EpinephrineIndication: Epinephrine is the first-line drug for all cardiac arrest rhythms.Mechanism of Action: Epinephrine... https://www.jove.com/v/17949 85 2025-07-31T20:24:37+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18437/18437_article_thumb_18437.jpg ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias Arrhythmia is a condition characterized by an irregular heart rhythm, with ECG changes that differ based on its origin and nature. The types of arrhythmias discussed below include atrial, junctional, and ventricular arrhythmias.Atrial ArrhythmiasPremature Atrial Complexes (PACs): PACs are early atrial beats caused by stress, caffeine, alcohol, electrolyte imbalances, hypoxia, hyperthyroidism, or certain medications (e.g., bronchodilators and decongestants). The ECG shows early P waves with an... https://www.jove.com/v/18437 85 2025-06-19T16:15:27+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52413.jpg A Rat Model of Ventricular Fibrillation and Resuscitation by Conventional Closed-chest Technique This article describes a rat model of electrically-induced ventricular fibrillation and resuscitation by chest compression, ventilation, and delivery of electrical shocks that simulates an episode of sudden cardiac arrest and conventional cardiopulmonary resuscitation. The model enables gathering insights on the pathophysiology of cardiac arrest and exploration of new resuscitation strategies. https://www.jove.com/v/52413 587 2015-04-26T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60707.jpg Standardized Model of Ventricular Fibrillation and Advanced Cardiac Life Support in Swine Cardiopulmonary resuscitation and defibrillation are the only effective therapeutic options during cardiac arrest caused by ventricular fibrillation. This model presents a standardized regimen to induce, assess, and treat this physiological state in a porcine model, thus providing a clinical approach with various opportunities for data collection and analysis. https://www.jove.com/v/60707 336 2020-01-30T23:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62110.jpg Utilizing Percutaneous Ventricular Assist Devices in Acute Myocardial Infarction Complicated by Cardiogenic Shock Percutaneous ventricular assist devices are increasingly being utilized in patients with acute myocardial infarction and cardiogenic shock. Herein, we discuss the mechanism of action and hemodynamic effects of such devices. We also review algorithms and best practices for the implantation, management and weaning of these complex devices. https://www.jove.com/v/62110 370 2021-06-12T20:00:00+00:00 JoVE no https://visualize.jove.com/12527732-angiotensin-ii-at1-receptor-stimulates-na-katpase-activity-through-a-pathway-involving-pkc-zeta-in-rat-thyroid-cells monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13325.jpg cAMP-dependent Protein Kinase Pathways Cyclic Adenosine Monophosphate (cAMP) is an essential second messenger that activates protein kinase A (PKA) and regulates various biological processes. A single epinephrine molecule binds to GPCR and activates several heterotrimeric G proteins, each stimulating multiple adenylyl cyclase, amplifying the signal, and synthesizing large numbers of cAMP molecules. Small changes in cAMP concentration affect PKA activity. The binding of four cAMP molecules induces a conformational change in PKA,... https://www.jove.com/v/13325 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14426.jpg Transducer Mechanism: Enzyme-Linked Receptors Enzyme-linked receptors are cell-surface receptors acting as an enzyme or associating with an enzyme intracellularly. They make excellent drug targets. Drugs can bind to the extracellular ligand-binding domain or directly affect their enzymatic domain and alter their activity. Major types that are helpful drug targets include: Receptor tyrosine kinases: Receptor tyrosine kinases (RTKs) phosphorylate specific tyrosines on the signaling proteins. RTKs include various growth factor receptors,... https://www.jove.com/v/14426 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14467.jpg Adrenergic Receptors: β Subtype β-adrenoceptors have varied sensitivities towards adrenaline, noradrenaline, and isoprenaline. The order of agonist potency is as follows: Isoprenaline > Adrenaline > Noradrenaline Neurotransmitter binding to these receptors causes activation of adenylyl cyclase resulting in increased concentrations of cAMP and modulation of calcium ion channels within the cell. They are further classified into β1, β2, and β3 subtypes. β1-adrenoceptors: β1-adrenoceptors have equal affinities for... https://www.jove.com/v/14467 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15023.jpg Antihypertensive Drugs: Angiotensin-Converting Enzyme Inhibitors Angiotensin-converting enzyme (ACE), a vital component of the renin-angiotensin-aldosterone system, is abundant in lung endothelial cells. ACE converts the inactive decapeptide, angiotensin I, into the active octapeptide, angiotensin II. This potent vasoconstrictor narrows blood vessels, increasing resistance to blood flow and elevating blood pressure. Angiotensin II also stimulates aldosterone production, encouraging kidney cells to reabsorb more sodium and water from urine, thereby increasing... https://www.jove.com/v/15023 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15024.jpg Antihypertensive Drugs: Angiotensin II Receptor Blockers In the renin-angiotensin-aldosterone system, a hormone called angiotensin II plays a crucial role. It binds to the AT1 receptors in vascular smooth muscles coupled with Gq proteins. The activation of these receptors activates an enzyme called phospholipase C, which releases two molecules: inositol trisphosphate and diacylglycerol. These molecules cause a chain reaction that leads to the phosphorylation of myosin light chains and promotes interaction between actin and myosin, leading to smooth... https://www.jove.com/v/15024 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15025.jpg Antihypertensive Drugs: Direct Renin Inhibitors The renin-angiotensin-aldosterone system (RAAS) is an intricate physiological pathway involving numerous enzymes and hormones, including renin, angiotensin-converting enzyme (ACE), angiotensin I and II, and aldosterone. Imbalances within this system increase the production of angiotensin II and aldosterone. Increased angiotensin II levels promote vasoconstriction and blood pressure elevation. Concurrently, higher aldosterone levels stimulate sodium and water reabsorption in the kidneys,... https://www.jove.com/v/15025 85 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52850.jpg Single-channel Analysis and Calcium Imaging in the Podocytes of the Freshly Isolated Glomeruli Changes in the intracellular calcium levels in the podocytes are one of the most important means to control the filtration function of glomeruli. Here we explain a high-throughput approach that allows detection of real-time calcium handling and single ion channels activity in the podocytes of the freshly isolated glomeruli. https://www.jove.com/v/52850 739 2015-06-27T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53035.jpg Implementing Patch Clamp and Live Fluorescence Microscopy to Monitor Functional Properties of Freshly Isolated PKD Epithelium Ion channels expressed in renal tubular epithelium play a significant role in the pathology of polycystic kidney disease. Here we describe experimental protocols used to perform patch-clamp analysis and intracellular calcium level measurements in cystic epithelium freshly isolated from rodent kidneys. https://www.jove.com/v/53035 526 2015-09-01T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53866.jpg Receptor Autoradiography Protocol for the Localized Visualization of Angiotensin II Receptors Here we present a protocol to describe the localization of angiotensin II Type 1 receptors in the rat brain by quantitative, densitometric, in vitro receptor autoradiography using an iodine-125 labeled analog of angiotensin II. https://www.jove.com/v/53866 723 2016-06-07T21:30:00+00:00 JoVE no https://visualize.jove.com/12537810-results-of-assisted-reproduction-techniques-in-latin-america monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10816.jpg Reproductive Cloning Reproductive cloning is the process of producing a genetically identical copy—a clone—of an entire organism. While clones can be produced by splitting an early embryo—similar to what happens naturally with identical twins—cloning of adult animals is usually done by a process called somatic cell nuclear transfer (SCNT). Somatic Cell Nuclear Transfer In SCNT, an egg cell is taken from an animal and its nucleus is removed, creating an enucleated egg. Then a somatic cell—any cell that is not a sex... https://www.jove.com/v/10816 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10816.jpg Reproductive Cloning Reproductive cloning is the process of producing a genetically identical copy—a clone—of an entire organism. While clones can be produced by splitting an early embryo—similar to what happens naturally with identical twins—cloning of adult animals is usually done by a process called somatic cell nuclear transfer (SCNT). Somatic Cell Nuclear Transfer In SCNT, an egg cell is taken from an animal and its nucleus is removed, creating an enucleated egg. Then a somatic cell—any cell that is not a sex... https://www.jove.com/v/12031 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16314.jpg In Vitro Fertilization In vitro fertilization (IVF) is a form of assisted reproductive technology where an egg is fertilized with sperm in a controlled laboratory environment before transferring the resulting embryo into the uterus. This process is designed to help individuals and couples experiencing difficulties conceiving. The IVF process begins with ovarian stimulation, during which reproductive endocrinologists prescribe hormonal medications to stimulate the ovaries to produce multiple eggs instead of the single... https://www.jove.com/v/16314 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16317.jpg Infertility in Males Male infertility affects millions of couples worldwide, arising from various factors that impact different stages of the reproductive process. An endocrine imbalance resulting from conditions like hypogonadism, Klinefelter syndrome, or pituitary disorders can disrupt hormone levels and reduce sperm production. Testicular defects, such as tumors, cryptorchidism, atrophic testes, abnormal sperm morphology, and low sperm count or motility, may arise due to genetic factors, structural... https://www.jove.com/v/16317 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16318.jpg Infertility in Females Female infertility is defined as the inability to conceive after a year of regular, unprotected intercourse and affects about 10–15% of couples worldwide. The primary cause of female infertility is ovulatory disorders, which hinder the release of eggs. These disorders can be classified as hypothalamic amenorrhea, polycystic ovarian syndrome (PCOS), premature ovarian failure, and hyperprolactinemic anovulation disorders. Endometriosis, a condition characterized by abnormal growth of endometrial... https://www.jove.com/v/16318 88 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58055.jpg Minimally Invasive Embryo Transfer and Embryo Vitrification at the Optimal Embryo Stage in Rabbit Model Assisted reproductive techniques (ARTs) are in continuous evaluation to improve outcomes and reduce the associated risks. This manuscript describes a minimally invasive embryo transfer procedure with an efficient cryopreservation protocol that allows the use of rabbits as an ideal animal model of human reproduction. https://www.jove.com/v/58055 422 2019-05-16T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59334.jpg Gamete Collection and In Vitro Fertilization of Astyanax mexicanus In vitro fertilization is a commonly used technique with a variety of model organisms to maintain lab populations and produce synchronized embryos for downstream applications. Here, we present a protocol that implements this technique for different populations of the Mexican tetra fish, Astyanax mexicanus. https://www.jove.com/v/59334 652 2019-05-25T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66212.jpg Monitoring Blood Glucose in Mouse Offspring After Intracytoplasmic Sperm Injection Here, we present a protocol to establish an intracytoplasmic sperm injection (ICSI)-embryo transfer (ET) mouse model, allowing us to observe age-related changes in glucose metabolism that may be attributed to ICSI, providing insights into its potential long-term impacts on human development. https://www.jove.com/v/66212 371 2024-05-17T13:40:00+00:00 JoVE no https://visualize.jove.com/12545026-estimation-of-pulmonary-artery-occlusion-pressure-by-an-artificial-neural-network monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/50247.jpg Direct Pressure Monitoring Accurately Predicts Pulmonary Vein Occlusion During Cryoballoon Ablation Effective pulmonary vein isolation utilizing a cryoballoon depends on complete pulmonary vein occlusion. The point of occlusion can be effectively predicted by direct analysis of pulmonary vein pressure waveform analysis during balloon inflation using a simple and reproducible technique. https://www.jove.com/v/50247 663 2013-02-26T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51082.jpg Assessing Cerebral Autoregulation via Oscillatory Lower Body Negative Pressure and Projection Pursuit Regression Cerebral perfusion is maintained across a range of pressures via cerebral autoregulation. However, characterizing autoregulation requires prominent pressure fluctuations at regulated frequencies. The described protocol will show how oscillatory lower body negative pressure can generate pressure fluctuations to provide data for projection pursuit regression for quantification of the autoregulatory curve. https://www.jove.com/v/51082 686 2014-12-10T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57405.jpg Invasive Hemodynamic Monitoring of Aortic and Pulmonary Artery Hemodynamics in a Large Animal Model of ARDS We present a protocol of creating right ventricular dysfunction in a pig model by inducing ARDS. We demonstrate invasive monitoring of left and right ventricular cardiac output using flow probes around the aorta and the pulmonary artery, as well as blood pressure measurements in the aorta and pulmonary artery. https://www.jove.com/v/57405 492 2018-11-26T20:30:00+00:00 JoVE no https://visualize.jove.com/12548028-effect-of-inspiratory-time-and-flow-settings-during-assist-control-ventilation monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13299.jpg Assessment of Ventilation I: Respiratory Rate Assessment of Ventilation A Ventilation assessment is critical for monitoring a patient's health status. Respiration, one of the most accessible vital signs, provides insights into the function of numerous body systems and can indicate serious health issues, such as brainstem injuries from head trauma. Critical Guidelines for Assessing Ventilation: Unobtrusive Observation: Maintaining accuracy in ventilation assessment is paramount. Observing the patient's breathing without their knowledge is... https://www.jove.com/v/13299 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15699.jpg Factors Affecting Pulmonary Ventilation Besides the pressure difference between the external environment and the lungs, the airflow rate and ease of pulmonary ventilation are also influenced by three other factors: surface tension of the fluid in the alveoli, compliance of the lungs, and airway resistance. Alveolar Surface Tension The alveolar fluid lines the luminal surface of the alveoli and exerts a force called surface tension. This force is caused by the polar water molecules in the liquid being more strongly attracted to each... https://www.jove.com/v/15699 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16398.jpg Mechanical Ventilation I: Indication and Settings Mechanical ventilation is a life-saving technique for managing acute respiratory failure and other respiratory complications. The process involves using a machine known as a ventilator to supply oxygen to the lungs and assist in removing carbon dioxide. It serves as a bridge to long-term mechanical ventilation or a temporary measure until ventilatory support is discontinued. The ventilator can maintain this function for a prolonged period, providing critical support for patients until they can... https://www.jove.com/v/16398 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16399.jpg Mechanical Ventilation II: Invasive Ventilation Ventilators are essential medical equipment used to aid patients with respiratory difficulties. Their primary function is to assist or replace spontaneous breathing by providing mechanical ventilation. There are two general classes of mechanical ventilators: negative-pressure and positive-pressure ventilators. Negative-Pressure Ventilators Negative-pressure ventilators create a vacuum around the chest or body to draw air into the lungs, simulating breathing. This method does not require an... https://www.jove.com/v/16399 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16400.jpg Mechanical Ventilation III: Noninvasive Ventilation Noninvasive positive-pressure ventilation (NIPPV), continuous positive airway pressure (CPAP), and bilevel positive airway pressure (BiPAP) are essential methods in respiratory care. These ventilation techniques offer unique benefits for patients with various respiratory conditions, providing adequate support without requiring intubation. Let's explore how each method is crucial in improving patient outcomes and enhancing respiratory therapy. Noninvasive Positive-Pressure Ventilation (NIPPV)<br... https://www.jove.com/v/16400 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16401.jpg Ventilatory Modes Mechanical ventilators are life-saving devices that support or replace spontaneous breathing. They deliver breaths to patients through varying methods known as ventilator modes. Understanding these modes is critical for healthcare providers managing patients with respiratory failure. There are three ventilatory modes: full support, partial support, and spontaneous. These are described below. Full Support Modes Full support modes include controlled mechanical ventilation, continuous mandatory... https://www.jove.com/v/16401 74 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64850.jpg Ex Vivo Porcine Experimental Model for Studying and Teaching Lung Mechanics We present an ex vivo pig lung model for the demonstration of pulmonary mechanics and alveolar recruitment maneuvers for teaching purposes. The lungs can be used for more than one day (up to five days) with minimal changes in pulmonary mechanics variables. https://www.jove.com/v/64850 729 2024-04-19T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66756.jpg Monitoring Lung Function with Electrical Impedance Tomography in the Intensive Care Unit Electrical Impedance Tomography is a non-invasive, radiation-free, real-time pulmonary ventilation monitoring tool. By measuring impedance changes in the thorax, it can visualize the distribution of air on a breath-by-breath basis. Initially intended for ventilation monitoring, electrical impedance tomography can also measure perfusion via intravenous injection of a saline solution. https://www.jove.com/v/66756 356 2024-09-06T20:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/70146.jpg Inspiratory Muscle Training as an Adjunct to the Treatment of Weaning Failure in Critically Ill Patients: A Practical Guide Respiratory muscle weakness is highly prevalent in patients weaning from mechanical ventilation. Resistive inspiratory muscle training (IMT) can improve inspiratory strength and potentially weaning outcomes. This protocol provides a structured approach to offer IMT to selected patients based on the best available knowledge, facilitating its wider application in critical care. https://www.jove.com/v/70146 256 2026-01-30T22:10:00+00:00 JoVE no https://visualize.jove.com/12560512-single-primer-amplification-spa-of-cdna-for-microarray-expression-analysis monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12014.jpg DNA Microarrays Microarrays are high-throughput and relatively inexpensive assays that can be automated to analyze large quantities of data at a time. They are used in genome-wide studies to compare gene or protein expression under two varied conditions, such as healthy and diseased states. Microarrays consist of glass or silica slides on which probe molecules are covalently attached through surface functionalization. Most commonly, the slides are prepared through the chemisorption of silanes to silica... https://www.jove.com/v/12014 154 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12019.jpg RACE - Rapid Amplification of cDNA Ends Rapid Amplification of cDNA Ends, or RACE, is one of the most effective methods to obtain a full-length cDNA from an mRNA sequence between a known internal region to the unknown sequence at the 5’ or 3’ end. The unknown region is cloned in the cDNA by a gene-specific primer that binds the known end, and a hybrid primer that attaches a predefined anchor sequence to the unknown end of the cDNA. The sequence in between is amplified by PCR with an anchor primer and a gene-specific primer. Since the... https://www.jove.com/v/12019 155 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51642.jpg Comprehensive Analysis of Transcription Dynamics from Brain Samples Following Behavioral Experience This manuscript describes a protocol that applies comprehensive profiling for analysis of transcriptional programs induced in specific brain nuclei of rodents following behavioral paradigms. Herein, this approach is illustrated in the context of profiling genes induced in the nucleus accumbens (NAc) of mice following acute cocaine exposure, utilizing microfluidic qPCR arrays. https://www.jove.com/v/51642 494 2014-08-26T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55219.jpg Single-cell Gene Expression Profiling Using FACS and qPCR with Internal Standards We describe a method to sort single mammalian cells and to quantify the expression of up to 96 target genes of interest in each cell. This method includes the use of internal qPCR standards to enable the estimation of absolute transcript counts. https://www.jove.com/v/55219 650 2017-02-25T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68619.jpg Comprehensive Spatial Profiling of Species-agnostic Transcriptomes via Stereo-seq This article presents a protocol to perform comprehensive spatial transcriptomic profiling of host, viral, fungal, and microbiome RNA from formalin-fixed paraffin-embedded tissue sections using Stereo-seq, which enables high-resolution mapping of diverse transcriptomes while preserving tissue architecture. https://www.jove.com/v/68619 622 2025-10-31T20:00:00+00:00 JoVE no https://visualize.jove.com/12564108-outcome-of-aortic-arch-surgery-in-patients-aged-70-years-or-older-axillary-artery-cannulation-and-selective-cerebral-perfusion-supports monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17976/17976_article_thumb_17976.jpg Peripheral Artery Disease III: Interprofessional Care Peripheral Artery Disease (PAD) is characterized by narrowed arteries that diminish blood flow to the extremities. Effective management of PAD requires an interprofessional approach involving various healthcare professionals. The critical aspects of interprofessional care for PAD patients focus on risk factor modification, drug therapy, exercise therapy, nutrition therapy, critical limb ischemia care, and interventional radiology and surgical procedures.The primary treatment goal for PAD... https://www.jove.com/v/17976 87 2025-06-19T16:18:24+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17978/17978_article_thumb_17978.jpg Peripheral Artery Disease V: Postoperative Nursing Management During the postoperative period, it is crucial to focus on maintaining circulation, identifying and managing potential complications, and planning for discharge.Nursing AssessmentVital signs monitoring: Regularly monitor vital signs, including blood pressure, heart rate, respiratory rate, and temperature, to detect early signs of complications such as bleeding and infection.Circulation assessment: Monitor pulses, perform Doppler assessments, and check capillary refill, color, temperature, and... https://www.jove.com/v/17978 83 2025-06-19T16:18:49+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17980/17980_article_thumb_17980.jpg Aneurysm II: Clinical Manifestations and Diagnostic Studies Thoracic, aortic arch and abdominal aneurysms are significant vascular conditions that can present with various clinical manifestations and lead to serious complications. Understanding these manifestations and the appropriate diagnostic studies is essential for effective management and treatment.Thoracic Aortic AneurysmsThoracic aortic aneurysms often remain asymptomatic until they reach a size that impinges on adjacent structures. They typically cause deep, diffuse chest pain that radiates to... https://www.jove.com/v/17980 81 2025-06-19T16:19:14+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17981/17981_article_thumb_17981.jpg Aneurysm III: Interprofessional Care Aneurysm management involves either conservative medical therapy or surgical intervention, depending on the size and symptoms of the aneurysm. Conservative management is generally reserved for smaller, asymptomatic aneurysms, while larger or symptomatic aneurysms often necessitate surgical repair.Conservative Medical TherapyFor small, asymptomatic aneurysms, particularly abdominal aortic aneurysms (AAA) less than 5.5 centimeters in diameter, conservative medical therapy is recommended. This... https://www.jove.com/v/17981 86 2025-06-19T16:19:25+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17982/17982_article_thumb_17982.jpg Aneurysm IV: Nursing Management Vigilant monitoring for aneurysm rupture is essential for patients undergoing aortic surgery.Preoperative Nursing ManagementContinuously monitor the patient for manifestations of aneurysm rupture, such as pallor, weakness, tachycardia, hypotension, abdominal, back, groin, or periumbilical pain, changes in consciousness, and a pulsating abdominal mass. Regularly assess the patient's peripheral pulses.Instruct the patient to consume a clear liquid diet the day before surgery and administer... https://www.jove.com/v/17982 82 2025-06-19T16:19:35+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57323.jpg Technique and Patient Selection Criteria of Right Anterior Mini-Thoracotomy for Minimal Access Aortic Valve Replacement The goal of this protocol is to describe in detail the technique of minimally invasive aortic valve replacement through a right anterior mini-thoracotomy and central aortic cannulation. This technique can potentially enhance patients' comfort and, by reducing post-operative morbidity, promote lowering the length of stay and global costs. https://www.jove.com/v/57323 530 2018-03-26T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62047.jpg Real-Time Assessment of Spinal Cord Microperfusion in a Porcine Model of Ischemia/Reperfusion Spinal cord microcirculation plays a pivotal role in spinal cord injury. Most methods do not allow real-time assessment of spinal cord microcirculation, which is essential for the development of microcirculation-targeted therapies. Here, we propose a protocol using Laser-Doppler-Flow Needle probes in a large animal model of ischemia/reperfusion. https://www.jove.com/v/62047 627 2020-12-10T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68033.jpg Novel and Innovative Hybrid Technique for Type A Aortic Dissection The protocol describes ascending aortic replacement combined with endovascular coverage of the entire aortic arch with a fenestrated stent graft in a patient with acute type A aortic dissection in the absence of a tear in the aortic arch. https://www.jove.com/v/68033 386 2025-03-28T21:55:00+00:00 JoVE no https://visualize.jove.com/12575454-specificity-of-gene-di-diabetes-insipidus-expression-in-homologous-inbred-rat-strains monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40886/40886_article_thumb_40886.jpg Diabetes Insipidus I: Introduction Definition Diabetes insipidus is a disorder marked by the production of large amounts of dilute urine because of impaired vasopressin production, release, or kidney response. The lack of effective vasopressin action limits water reabsorption in the renal collecting ducts, which leads to excessive urinary water loss and intense thirst.Clinical PresentationIndividuals with diabetes insipidus report persistent thirst and very high urine output. In severe cases, fluid intake can reach up to 20... https://www.jove.com/v/40886 89 2026-04-13T21:37:43+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40887/40887_article_thumb_40887.jpg Diabetes Insipidus II: Pathophysiology Normally, water balance is maintained through three interconnected mechanisms: the hypothalamic thirst center, the synthesis and release of antidiuretic hormone (ADH, or vasopressin), and the kidneys' responsiveness to this hormone. ADH is synthesized in the hypothalamus, released from the posterior pituitary, and acts on the distal nephron, allowing water reabsorption and concentrated urine production.Diabetes Insipidus and Its TypesIn diabetes insipidus (DI), this regulatory system is... https://www.jove.com/v/40887 82 2026-04-13T21:37:51+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50366.jpg Culturing Primary Rat Inner Medullary Collecting Duct Cells Arginine-vasopressin (AVP) controls fine-tuning of body water homeostasis through facilitating water reabsorption by renal principal cells. Here, we present a protocol for the cultivation of primary rat inner medullary collecting duct cells suitable for the elucidation of molecular mechanisms underlying AVP-mediated water reabsorption. https://www.jove.com/v/50366 371 2013-06-21T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56133.jpg Evaluation of Vascular Control Mechanisms Utilizing Video Microscopy of Isolated Resistance Arteries of Rats This manuscript describes in vitro video microscopy protocols for evaluating vascular function in rat cerebral resistance arteries. The manuscript also describes techniques for evaluating microvessel density with fluorescently labeled lectin and tissue perfusion using Laser Doppler Flowmetry. https://www.jove.com/v/56133 628 2017-12-05T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/70414.jpg Pancreatic Islet Isolation and Purification from Lewis Rats Using Enzymatic Digestion and Density-Gradient Separation This protocol describes a standardized method for surgical harvesting, enzymatic digestion, and density-gradient purification of Lewis rat pancreatic islets, enabling high-yield, high-purity preparations for direct use in transplantation or in vitro studies. https://www.jove.com/v/70414 464 2026-04-03T19:53:00+00:00 JoVE no https://visualize.jove.com/12641234-immobilized-particle-arrays-coalescence-of-planar-and-suspension-array-technologies monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3636.jpg Polymer Microarrays for High Throughput Discovery of Biomaterials A description of the formation of a polymer microarray using an on-chip photopolymerization technique. The high throughput surface characterization using atomic force microscopy, water contact angle measurements, X-ray photoelectron spectroscopy and time of flight secondary ion mass spectrometry and a cell attachment assay is also described. https://www.jove.com/v/3636 817 2012-01-25T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13888.jpg Colloids and Suspensions Children at play often make suspensions such as mixtures of mud and water, flour and water, or a suspension of solid pigments in water known as tempera paint. These suspensions are heterogeneous mixtures composed of relatively large particles visible to the naked eye or seen with a magnifying glass. They are cloudy, and the suspended particles settle out after mixing. The suspended particles in a suspension settle out after some time of mixing. The separation of particles from a suspension is... https://www.jove.com/v/13888 77 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51501.jpg Formation of Biomembrane Microarrays with a Squeegee-based Assembly Method Supported lipid bilayers and natural membrane particles are convenient systems that can approximate the properties of cell membranes and be incorporated in a variety of analytical strategies. Here we demonstrate a method for preparing microarrays composed of supported lipid bilayer-coated SiO2 beads, phospholipid vesicles or natural membrane particles. https://www.jove.com/v/51501 476 2014-05-08T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63131.jpg Patterning of Microorganisms and Microparticles through Sequential Capillarity-assisted Assembly We present a technology that uses capillarity-assisted assembly in a microfluidic platform to pattern micro-sized objects suspended in a liquid, such as bacteria and colloids, into prescribed arrays on a polydimethylsiloxane substrate. https://www.jove.com/v/63131 617 2021-11-04T20:00:00+00:00 JoVE no https://visualize.jove.com/12661913-effects-of-hormone-replacement-therapy-on-serum-angiotensin-converting-enzyme-activity-and-plasma-bradykinin-in-postmenopausal-women-according-to-angiotensin-converting-enzyme-genotype monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10893.jpg Hormonal Regulation The renin-aldosterone system is an endocrine system which guides the renal absorption of water and electrolytes, thus managing blood pressure and osmoregulation. Activation of the system begins in the kidneys with a small cluster of cells adjacent to the afferent and efferent blood vessels of the renal corpuscle. As the nephrons are filtering blood, juxtaglomerular cells monitor blood pressure. If they detect a decrease in pressure, they release the hormone renin into the bloodstream. <br... https://www.jove.com/v/10893 93 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15020.jpg Antihypertensive Drugs: Action of β 1 Blockers β1-receptors are primarily located in the heart and kidneys. In cardiac myocytes, these receptors interact with neurotransmitters released by the sympathetic nervous system during heightened activity or danger. As a result, β1-receptors get activated, initiating a series of biochemical processes. Excessive activation of beta receptors due to chronic stress can abnormally increase heart rate and contractility, resulting in high blood pressure or hypertension. To counteract this, β1-blockers... https://www.jove.com/v/15020 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15023.jpg Antihypertensive Drugs: Angiotensin-Converting Enzyme Inhibitors Angiotensin-converting enzyme (ACE), a vital component of the renin-angiotensin-aldosterone system, is abundant in lung endothelial cells. ACE converts the inactive decapeptide, angiotensin I, into the active octapeptide, angiotensin II. This potent vasoconstrictor narrows blood vessels, increasing resistance to blood flow and elevating blood pressure. Angiotensin II also stimulates aldosterone production, encouraging kidney cells to reabsorb more sodium and water from urine, thereby increasing... https://www.jove.com/v/15023 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15024.jpg Antihypertensive Drugs: Angiotensin II Receptor Blockers In the renin-angiotensin-aldosterone system, a hormone called angiotensin II plays a crucial role. It binds to the AT1 receptors in vascular smooth muscles coupled with Gq proteins. The activation of these receptors activates an enzyme called phospholipase C, which releases two molecules: inositol trisphosphate and diacylglycerol. These molecules cause a chain reaction that leads to the phosphorylation of myosin light chains and promotes interaction between actin and myosin, leading to smooth... https://www.jove.com/v/15024 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15025.jpg Antihypertensive Drugs: Direct Renin Inhibitors The renin-angiotensin-aldosterone system (RAAS) is an intricate physiological pathway involving numerous enzymes and hormones, including renin, angiotensin-converting enzyme (ACE), angiotensin I and II, and aldosterone. Imbalances within this system increase the production of angiotensin II and aldosterone. Increased angiotensin II levels promote vasoconstriction and blood pressure elevation. Concurrently, higher aldosterone levels stimulate sodium and water reabsorption in the kidneys,... https://www.jove.com/v/15025 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15037.jpg Heart Failure Drugs: Inhibitors of Renin-Angiotensin System The activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) contributes to cardiac remodeling, and inhibiting the RAAS is a pharmacological target in heart failure management. As a result, neurohumoral modulation is a crucial treatment principle for managing heart failure. This approach involves using medications like ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), β-blockers, mineralocorticoid receptor antagonists (MRAs), and neutral... https://www.jove.com/v/15037 86 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53866.jpg Receptor Autoradiography Protocol for the Localized Visualization of Angiotensin II Receptors Here we present a protocol to describe the localization of angiotensin II Type 1 receptors in the rat brain by quantitative, densitometric, in vitro receptor autoradiography using an iodine-125 labeled analog of angiotensin II. https://www.jove.com/v/53866 723 2016-06-07T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59536.jpg An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause Clinically, estrogen deficiency in menopausal women may aggravate the incidence of lipid disruption and atherosclerosis. We established an in vivo estrogen deficiency model by bilateral ovariectomy via a double dorsal-lateral incision in apoE-/- mice. The mouse model is applicable for screening exogenous estrogen treatments of cardiovascular dysfunction after menopause. https://www.jove.com/v/59536 378 2019-08-13T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64884.jpg Estrogen-Like Effect of Bazi Bushen Capsule in Ovariectomized Rats Presented here is a protocol to show that Bazi Bushen capsule (BZBS) can regulate the RANKL/OPG signaling pathway in the ovariectomized rodent model through its estrogen-like effect. https://www.jove.com/v/64884 536 2023-04-07T21:40:00+00:00 JoVE no https://visualize.jove.com/12662675-artificial-neural-networks-as-approximators-of-stochastic-processes monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16099.jpg Linear Approximation in Frequency Domain Linear systems are characterized by two main properties: superposition and homogeneity. Superposition allows the response to multiple inputs to be the sum of the responses to each individual input. Homogeneity ensures that scaling an input by a scalar results in the response being scaled by the same scalar. In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear. https://www.jove.com/v/16099 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16103.jpg Linear Approximation in Time Domain Nonlinear systems often require sophisticated approaches for accurate modeling and analysis, with state-space representation being particularly effective. This method is especially useful for systems where variables and parameters vary with time or operating conditions, such as in a simple pendulum or a translational mechanical system with nonlinear springs. For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length, the... https://www.jove.com/v/16103 81 JoVE no https://cloudfront.jove.com/files/ftp_upload/19809/19809_article_thumb_19809_TN.jpg Linearization and Approximation Linearization is a mathematical technique used to approximate complex, nonlinear functions with simpler linear models in the vicinity of a chosen reference point. The method is based on the idea that, although a function may be difficult to evaluate exactly, its behavior near a specific input value can often be closely approximated by the tangent line at that point. This approach is particularly useful when small deviations from a known value are involved.Consider the square root function, for... https://www.jove.com/v/19809 86 2026-01-12T20:24:20+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19810/19810_article_thumb_19810_TN.jpg Application of Linearization and Approximation A drone flying through complex terrain often relies on more than one sensing method to estimate small changes in altitude. Along with direct measurements, air pressure provides a useful indirect indicator of vertical movement. Atmospheric pressure decreases as altitude increases, and this relationship is commonly described using an exponential model. Although accurate, converting pressure measurements into altitude values requires calculations that are too complex to perform repeatedly during... https://www.jove.com/v/19810 89 2026-01-12T20:24:59+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19849/19849_article_thumb_19849_TN.jpg Newton’s Method Newton’s Method is a powerful iterative technique for approximating the roots of real-valued, differentiable functions, particularly when analytical solutions are impractical. This approach is widely used in scientific computing, engineering, and finance, where equations may be too complex for traditional algebraic methods to handle. The method relies on an iterative process that refines an initial estimate using the function’s derivative to approach the true solution progressively. https://www.jove.com/v/19849 90 2026-01-12T20:24:54+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40580/40580_article_thumb_40580_TN.jpg Approximate Integration In many practical and theoretical contexts, the exact value of a definite integral may be inaccessible. This limitation typically arises when the antiderivative of a function is either unknown or cannot be expressed in a closed mathematical form. Alternatively, it can occur when a function is defined not by a formula but by a finite set of empirical data points, such as those collected during experiments. In these cases, approximate integration techniques provide a valuable solution.One of the... https://www.jove.com/v/40580 84 2026-01-12T20:24:45+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67576.jpg Surrogate Model Development for Digital Experiments in Welding This protocol outlines a general workflow for constructing an artificial neural network for welding simulation using datasets generated automatically through Python scripts with macro functions. The workflow is validated against a benchmark case involving single-pass, straight-line welding. The surrogate model's predictive accuracy shows a strong agreement with finite element simulations. https://www.jove.com/v/67576 557 2025-03-28T20:30:00+00:00 JoVE no https://visualize.jove.com/12719886-dna-microarray-analysis-in-malignant-lymphomas monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2546.jpg DNA Microarrays: Sample Quality Control, Array Hybridization and Scanning We demonstrate the use of DNA microarrays for expression profiling of the nervous system. We describe RNA quality control, sample labeling, and array hybridization and scanning. https://www.jove.com/v/2546 567 2011-03-15T18:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12014.jpg DNA Microarrays Microarrays are high-throughput and relatively inexpensive assays that can be automated to analyze large quantities of data at a time. They are used in genome-wide studies to compare gene or protein expression under two varied conditions, such as healthy and diseased states. Microarrays consist of glass or silica slides on which probe molecules are covalently attached through surface functionalization. Most commonly, the slides are prepared through the chemisorption of silanes to silica... https://www.jove.com/v/12014 154 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55773.jpg Comprehensive DNA Methylation Analysis Using a Methyl-CpG-binding Domain Capture-based Method in Chronic Lymphocytic Leukemia Patients This work describes an optimized methyl-CpG-binding domain (MBD) sequencing protocol and a computational pipeline to identify differentially methylated CpG-rich regions in chronic lymphocytic leukemia (CLL) patients. https://www.jove.com/v/55773 801 2017-06-16T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58711.jpg Multiplexed Fluorescent Immunohistochemical Staining, Imaging, and Analysis in Histological Samples of Lymphoma Here we describe a protocol for multiplex fluorescent immunohistochemical staining and imaging for the simultaneous localization of multiple cancer-associated antigens in lymphoma. This protocol can be extended to the colocalization analysis of biomarkers within all tissue sections. https://www.jove.com/v/58711 472 2019-01-09T22:00:00+00:00 JoVE no https://visualize.jove.com/12739847-improving-the-design-of-augmentative-and-alternative-technologies-for-young-children monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3675.jpg Eye Tracking Young Children with Autism Eye tracking has long been used to study gaze patterns in typically-developing individuals, but recent technological advancements have made its use with clinical populations, including autism, more feasible. While eye-tracking young children with autism can offer insight into early symptom manifestations, it involves methodological challenges. Suggestions for best practices are provided. https://www.jove.com/v/3675 543 2012-03-27T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18627.jpg Modeling in Therapy Modeling, a key technique in therapy, uses observational learning to help clients acquire and practice new skills by watching therapists demonstrate desired behaviors. This approach, rooted in Albert Bandura's concept of vicarious learning, plays a significant role in therapeutic interventions for various psychological conditions, including social anxiety, ADHD, and depression. Participant Modeling Participant modeling involves therapists demonstrating calm and effective behaviors in situations... https://www.jove.com/v/18627 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/19610.jpg Autism Spectrum Disorder Autism spectrum disorder (ASD) is a neurodevelopmental condition marked by persistent deficits in social communication and interaction alongside restrictive and repetitive behaviors or interests. ASD is sometimes accompanied by intellectual impairment. These core symptoms manifest differently among individuals, ranging from mild to severe. The disorder's complexity extends beyond its clinical presentation, encompassing a diverse range of biological, cognitive, and sociocultural influences.<br... https://www.jove.com/v/19610 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/19615.jpg Learning Disabilities Learning disabilities are cognitive disorders caused by neurological impairments that affect cognitive functions like language and reading, without indicating overall intellectual or developmental challenges. These disabilities differ from global intellectual or developmental disabilities as they are limited to distinct cognitive functions. Common learning disabilities include dysgraphia, dyslexia, and dyscalculia, each of which impacts unique aspects of learning. Dyslexia Dyslexia is a... https://www.jove.com/v/19615 85 2025-08-04T17:44:39+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52286.jpg Practical Methodology of Cognitive Tasks Within a Navigational Assessment Children who have complex communication needs can benefit from the use of a speech-generating device (SGD). Cognitive skills were identified as having an impact on the ability to navigate between levels of SGDs. This protocol describes the steps needed for Speech-language Pathologists to assess cognitive skills and navigational abilities. https://www.jove.com/v/52286 319 2015-06-01T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60247.jpg Measuring the Functional Abilities of Children Aged 3-6 Years Old with Observational Methods and Computer Tools We present a protocol to use a computational tool to record and analyze the functional abilities of children aged 3-6 years old. The protocol facilitates the comparison of these abilities throughout their development and can be used to assess developmental difficulties. https://www.jove.com/v/60247 689 2020-06-20T19:30:00+00:00 JoVE no https://visualize.jove.com/12750899-early-and-late-patterns-of-stimulus-related-activity-in-auditory-cortex-of-trained-animals monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3598.jpg Behavioral Determination of Stimulus Pair Discrimination of Auditory Acoustic and Electrical Stimuli Using a Classical Conditioning and Heart-rate Approach The application of a classical fear conditioning behavioral paradigm for auditory prosthetic research in rats is described. This paradigm provides a mechanism for identifying both detection of, and discrimination between, distinct acoustic and electrical stimuli using heart-rate as an outcome measure. https://www.jove.com/v/3598 650 2012-06-06T12:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14970.jpg Auditory Pathway Auditory pathways constitute the complex neural circuits responsible for transmitting and interpreting auditory information from the peripheral auditory system to the brain. Sound waves are initially captured by the outer ear, funneled through the ear canal, and reach the tympanic membrane (eardrum). These vibrations are transmitted via the middle ear's ossicles to the inner ear's cochlea. When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking the... https://www.jove.com/v/14970 75 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53002.jpg Combined Shuttle-Box Training with Electrophysiological Cortex Recording and Stimulation as a Tool to Study Perception and Learning Shuttle-box avoidance learning is well-established in behavioral neuroscience. This protocol describes how shuttle-box learning in rodents can be combined with site-specific electrical intracortical microstimulation (ICMS) and simultaneous chronical in vivo recordings as a tool to study multiple aspects of learning and perception. https://www.jove.com/v/53002 523 2015-10-22T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56429.jpg Stereotactically-guided Ablation of the Rat Auditory Cortex, and Localization of the Lesion in the Brain We describe a method for the stereotactically-guided location, exposure, and ablation of the auditory cortex in rats. The localization of the ablation is assessed using a coordinate map postmortem. https://www.jove.com/v/56429 569 2017-10-11T12:30:00+00:00 JoVE no https://visualize.jove.com/12780165-interspike-interval-embedding-of-chaotic-signals monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16030.jpg Classification of Signals In signal processing, signals are classified based on various characteristics: continuous-time versus discrete-time, periodic versus aperiodic, analog versus digital, and causal versus noncausal. Each category highlights distinct properties crucial for understanding and manipulating signals. A continuous-time signal holds a value at every instant in time, representing information seamlessly. In contrast, a discrete-time signal holds values only at specific moments, often denoted as x(n), where... https://www.jove.com/v/16030 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16039.jpg Even and Odd Signals An even signal, whether in continuous-time or discrete-time, is defined by its symmetry with its time-reversed version. Mathematically, this is represented as for continuous-time signals and for discrete-time signals. Even signals exhibit symmetry around the vertical axis, meaning the signal for negative time values mirrors that for positive time values. In contrast, a signal is termed odd if it does not match its time-reversed counterpart, represented by for continuous-time signals and for... https://www.jove.com/v/16039 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16040.jpg Basic Continuous Time Signals Basic continuous-time signals include the unit step function, unit impulse function, and unit ramp function, collectively referred to as singularity functions. Singularity functions are characterized by discontinuities or discontinuous derivatives. The unit step function, denoted u(t), is zero for negative time values and one for positive time values, exhibiting a discontinuity at t=0. This function often represents abrupt changes, such as the step voltage introduced when turning a car's... https://www.jove.com/v/16040 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16043.jpg Basic Discrete Time Signals The unit step sequence is defined as 1 for zero and positive values of the integer n. This sequence can be graphically displayed using a set of eight sample points, showing a step function starting from n=0 and remaining constant thereafter. The unit impulse or sample sequence is mathematically expressed as zero for all n values except at n=0, where it is one. The unit impulse sequence, denoted by δ(n), is the first difference of the unit step sequence, while the unit step sequence u(n) is the... https://www.jove.com/v/16043 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16077.jpg Sampling Continuous Time Signal In signal processing, a continuous-time signal can be sampled using an impulse-train sampling technique, followed by the zero-order hold method. Impulse-train sampling involves the use of a periodic impulse train, which consists of a series of delta functions spaced at regular intervals determined by the sampling period. When a continuous-time signal is multiplied by this impulse train, it generates impulses with amplitudes corresponding to the signal's values at the sampling points. In the... https://www.jove.com/v/16077 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16078.jpg Reconstruction of Signal using Interpolation Signal processing techniques are essential for accurately converting continuous signals to digital formats and vice versa. When a continuous signal is sampled with a period T, the resulting sampled signal exhibits replicas of the original spectrum in the frequency domain, spaced at intervals equal to the sampling frequency. To handle this sampled signal, a zero-order hold method can be applied, which creates a piecewise constant signal by retaining each sample's value until the next sampling... https://www.jove.com/v/16078 70 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51283.jpg Recording Single Neurons' Action Potentials from Freely Moving Pigeons Across Three Stages of Learning Learning new stimulus-response associations engages a wide range of neural processes which are ultimately reflected in changing spike output of individual neurons. Here we describe a behavioral protocol allowing for the continuous registration of single-neuron activity while animals acquire, extinguish, and reacquire a conditioned response within a single experimental session. https://www.jove.com/v/51283 680 2014-06-02T20:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52877.jpg Generation of Local CA1 γ Oscillations by Tetanic Stimulation Oscillations are fundamental network properties and are modulated by disease and drugs. Studying brain-slice oscillations allows characterization of isolated networks under controlled conditions. Protocols are provided for the preparation of acute brain slices for evoking CA1 γ oscillations. https://www.jove.com/v/52877 482 2015-08-14T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59812.jpg Using Neuron Spiking Activity to Trigger Closed-Loop Stimuli in Neurophysiological Experiments This protocol demonstrates how to use an electrophysiological system for closed-loop stimulation triggered by neuronal activity patterns. Sample Matlab code that can be easily modified for different stimulation devices is also provided. https://www.jove.com/v/59812 319 2019-11-12T19:00:00+00:00 JoVE no https://visualize.jove.com/12794573-total-anorectal-reconstruction-with-the-artificial-bowel-sphincter-report-of-eight-cases-a-quality-of-life-assessment monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16413.jpg Assessment of the Rectum and Anus Evaluating the rectum and anus plays a crucial role in conducting a thorough physical examination of the gastrointestinal system. Although it may be uncomfortable and often embarrassing for the patient, it holds immense diagnostic value, particularly in detecting gastrointestinal diseases and abnormalities. This guide will explain how to perform this assessment using inspection and palpation methods. Rectal Inspection Begin by inspecting the perianal and anal areas for color, texture, rashes,... https://www.jove.com/v/16413 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16444.jpg Inflammatory Bowel Disease V: Surgical Management Surgical interventions for inflammatory bowel disease (IBD), which includes ulcerative colitis and Crohn's disease, are essential in managing symptoms and addressing complications. The selection of surgical procedures is contingent upon the specific conditions and complications that stem from these illnesses. Here are some common surgical interventions for IBD: Strictureplasty Proctocolectomy or total colectomy with ileostomy Restorative proctocolectomy with Ileal pouch-anal anastomosis<br... https://www.jove.com/v/16444 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62919.jpg Robot-assisted Total Mesorectal Excision and Lateral Pelvic Lymph Node Dissection for Locally Advanced Middle-low Rectal Cancer The robotic technique described herein aims to detail a stepwise approach to robot-assisted total mesorectal excision and lateral pelvic lymph node dissection for locally advanced (T3/T4) rectal cancer located below the peritoneal reflection. https://www.jove.com/v/62919 765 2022-02-12T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63592.jpg Retzius-Sparing Robot-Assisted Radical Prostatectomy Robot-assisted Retzius-sparing radical prostatectomy is a technique that enables to preserve urinary continence or facilitates recovery of urinary continence in the majority of patients. Patients must be informed about the risk of a positive surgical margin. https://www.jove.com/v/63592 730 2022-05-19T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63678.jpg Transcorporal Artificial Urinary Sphincter Cuff Placement in a Case Requiring Revision for Urethral Atrophy Here we describe the application of transcorporal artificial urethral sphincter (AUS) placement in a case requiring revision of an artificial urinary sphincter for urethral atrophy. https://www.jove.com/v/63678 205 2022-06-16T20:00:00+00:00 JoVE no https://visualize.jove.com/12812404-office-based-anesthesia-an-overview monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14500.jpg Local Anesthetics: Common Agents and Their Applications Local anesthetics (LAs) are commonly used for various applications in medical and dental procedures. Some of the common agents used are cocaine, lidocaine, and bupivacaine. Cocaine is an ester of benzoic acid and methylecgogine. It is used to anesthetize and vasoconstrict locally. Currently, it is used primarily for topical applications. It is beneficial for surgeries on the upper respiratory tract, providing anesthesia and shrinking the mucosa. Cocaine in the form of cocaine hydrochloride is... https://www.jove.com/v/14500 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14502.jpg Local Anesthetics: Clinical Application as Surface, Infiltration, and Conduction Block Anesthesia Depending on the target organ, local anesthetics (LAs) can be administered via various routes. In surface anesthesia, LAs are applied directly to the surface of the skin or mucous membranes. It is widely used for topical skin numbing before venipuncture or minor surgical procedures. Commonly used surface local anesthetics are lidocaine or benzocaine sprays or creams. Surface anesthesia occurs within 5 minutes and lasts for about 60 minutes. One of the main disadvantages of topical anesthesia is... https://www.jove.com/v/14502 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14748.jpg Local Anesthetics: Clinical Application as Epidural Anesthesia Epidural anesthetics are administered in the fat-filled epidural space, the outermost part of the spinal canal. This technique is commonly employed for pain management and anesthesia during lower abdomen and pelvis surgeries or labor and delivery. Since epidural anesthetics can be infused through an epidural catheter, all types of drugs, including short-acting ones, can be administered. Chloroprocaine and lidocaine are examples of short and long-duration anesthetics, respectively. Bupivacaine... https://www.jove.com/v/14748 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15188.jpg General Anesthesia: Overview Anesthesia is a medical procedure that uses drugs for CNS suppression to enable painless surgeries and procedures. The selection of anesthetics is influenced by their pharmacokinetic properties, side effects, and patient characteristics. Various types of anesthesia include general, local, regional, spinal, and inhalational. General anesthesia induces unconsciousness in the whole body, while the others target specific areas or sensations. It is administered to minimize adverse effects, maintain... https://www.jove.com/v/15188 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15189.jpg Stages of General Anesthesia Various sedation levels offer significant advantages in facilitating procedural interventions for patients undergoing medical or invasive surgical procedures. These levels span from anxiolysis to general anesthesia, providing a spectrum of sedative effects to cater to specific patient needs. Anxiolysis reduces anxiety and is achieved through minimal sedation, enabling patients to remain awake and responsive while feeling more at ease during the procedure. This level can benefit minor... https://www.jove.com/v/15189 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15191.jpg Inhalational Anesthetics: Overview Inhalation anesthetics are drugs that induce general anesthesia upon inhalation. They work by increasing the sensitivity of GABAA receptors or inhibiting NMDA receptors, leading to a decrease in central nervous system activity. The depth of anesthesia can be rapidly adjusted by changing the concentration of the inhaled gas. Some common examples of inhalational anesthetics include volatile liquids like isoflurane, desflurane, sevoflurane and gases like xenon and nitrous oxide. Isoflurane, a... https://www.jove.com/v/15191 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56346.jpg Proper Positioning and Restraint of a Rat Hind Limb for Focused High Resolution Imaging of Bone Micro-architecture Using In Vivo Micro-computed Tomography This paper instructs users of in vivo micro-computed tomography (µCT) scanners how to anesthetize, correctly position and restrain the hind limb of a rat for minimal movement during high-resolution imaging of the tibia. The result is high quality images that can be processed to accurately quantify bone micro-architecture. https://www.jove.com/v/56346 264 2017-11-22T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56881.jpg Recording Brain Electromagnetic Activity During the Administration of the Gaseous Anesthetic Agents Xenon and Nitrous Oxide in Healthy Volunteers Simultaneous magnetoencephalography and electroencephalography provides a useful tool to search for common and distinct macro-scale mechanisms of reductions in consciousness induced by different anesthetics. This paper illustrates the empirical methods underlying the recording of such data from healthy humans during N-Methyl-D-Aspartate-(NMDA)-receptor-antagonist-based anesthesia during inhalation of nitrous oxide and xenon. https://www.jove.com/v/56881 892 2018-01-13T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59702.jpg CO 2 -Lasertonsillotomy Under Local Anesthesia in Adults CO2-lasertonsillotomy under local anesthesia is an interesting alternative treatment method for tonsillectomy under general anesthesia for tonsil-related complaints in adults. This report presents a step-by-step protocol detailing the execution of CO2-lasertonsillotomy under local anesthesia. https://www.jove.com/v/59702 307 2019-11-06T21:00:00+00:00 JoVE no https://visualize.jove.com/12815016-spectrotemporal-structure-of-receptive-fields-in-areas-ai-and-aaf-of-mouse-auditory-cortex monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10855.jpg The Cochlea The cochlea is a coiled structure in the inner ear that contains hair cells—the sensory receptors of the auditory system. Sound waves are transmitted to the cochlea by small bones attached to the eardrum called the ossicles, which vibrate the oval window that leads to the inner ear. This causes fluid in the chambers of the cochlea to move, vibrating the basilar membrane. The basilar membrane extends from the basal end of the cochlea near the oval window to the apical end at its tip. Although... https://www.jove.com/v/10855 73 2025-10-23T18:49:24+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14907.jpg Motor and Sensory Areas of the Cortex The cerebral cortex, the brain's outermost layer, is pivotal in processing complex cognitive tasks, emotions, and various sensory inputs and executing voluntary motor activities. This intricate structure is divided into three primary functional areas: the motor areas, sensory areas, and association areas. Motor Areas The motor areas located in the frontal lobe are central to controlling voluntary movements. This region is further subdivided into the primary motor cortex and the premotor cortex. https://www.jove.com/v/14907 74 2025-06-13T16:10:51+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14908.jpg Association Areas of the Cortex Association areas are regions of the cerebral cortex that do not have a specific sensory or motor function. Instead, they integrate and interpret information from various sources to enable higher cognitive processes such as memory, learning, and decision-making. Some key association areas include the following: Prefrontal Association Area: This area is located in the frontal lobe and is involved in planning, decision-making, and moderating social behavior. It connects with primary motor areas,... https://www.jove.com/v/14908 81 2025-06-13T16:11:09+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14970.jpg Auditory Pathway Auditory pathways constitute the complex neural circuits responsible for transmitting and interpreting auditory information from the peripheral auditory system to the brain. Sound waves are initially captured by the outer ear, funneled through the ear canal, and reach the tympanic membrane (eardrum). These vibrations are transmitted via the middle ear's ossicles to the inner ear's cochlea. When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking the... https://www.jove.com/v/14970 75 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50872.jpg Functional Imaging of Auditory Cortex in Adult Cats using High-field fMRI Functional studies of the auditory system in mammals have traditionally been conducted using spatially-focused techniques such as electrophysiological recordings. The following protocol describes a method of visualizing large-scale patterns of evoked hemodynamic activity in the cat auditory cortex using functional magnetic resonance imaging. https://www.jove.com/v/50872 650 2014-02-19T22:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59189.jpg Morphological and Functional Evaluation of Ribbon Synapses at Specific Frequency Regions of the Mouse Cochlea This manuscript describes an experimental protocol for evaluating the morphological characteristics and functional status of ribbon synapses in normal mice. The present model is also suitable for noise-induced and age-related cochlear synaptopathy-restricted models. The correlative results of previous mouse studies are also discussed. https://www.jove.com/v/59189 594 2019-05-10T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67983.jpg Multiscale Investigations of Cortical Processing by Integrating Laminar Polytrodes and Optogenetics with Micro Electrocorticography in Rodents Here, we present two protocols for high-density micro-electrocorticography (µEcoG) recording in rats and mice, including surgical, implantation, and recording methods. µECoG recordings are performed in combination with either laminar polytrode recording in the rat auditory cortex or with optogenetic manipulation of neural activity in the mouse somatosensory cortex. https://www.jove.com/v/67983 472 2025-05-23T20:30:00+00:00 JoVE no https://visualize.jove.com/12817151-inhibited-and-uninhibited-infants-grown-up-adult-amygdalar-response-to-novelty monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12186.jpg Long-term Depression Long-term depression, or LTD, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTD is the process of synaptic weakening that occurs over time between pre and postsynaptic neuronal connections. The synaptic weakening of LTD works in opposition to synaptic strengthening by long-term potentiation (LTP) and together are the main mechanisms that underlie learning and memory. Calcium Ion Concentration Mechanism If over time, all... https://www.jove.com/v/12186 63 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53652.jpg Measuring Cardiac Autonomic Nervous System (ANS) Activity in Toddlers - Resting and Developmental Challenges We describe the methods for continuous monitoring of the autonomic nervous system under resting and challenge conditions with 18 month old children. Results revealed that this protocol can produce meaningful physiological responses in both branches of the autonomic nervous system and elicit significant individual variability in patterns of responses. https://www.jove.com/v/53652 502 2016-02-25T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55261.jpg Neurodevelopmental Reflex Testing in Neonatal Rat Pups Behavioral testing is the gold standard for determining outcomes following brain injury, and can identify the presence of developmental disabilities in infants and children. Neurodevelopmental reflexes are an early indicator of these abnormalities. A host of easily accomplished developmental reflex tests in the neonatal rodent were developed and described here. https://www.jove.com/v/55261 575 2017-04-24T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64702.jpg Analysis of Effect of Compound Salt Stress on Seed Germination and Salt Tolerance Analysis of Pepper ( Capsicum annuum L.) The paper below presents a protocol for measuring seed germination, seedling growth, and physiological indexes of two pepper varieties with salinity tolerance differences in response to six mixed salt concentrations. This protocol can be used to evaluate the salt tolerance of pepper varieties. https://www.jove.com/v/64702 507 2022-11-30T15:00:00+00:00 JoVE no https://visualize.jove.com/12832760-improving-macromolecular-atomic-models-at-moderate-resolution-by-automated-iterative-model-building-statistical-density-modification-and-refinement monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11251.jpg Molecular Models Physical models representing molecular architectures of chemical compounds play essential roles in understanding chemistry. The use of molecular models makes it easier to visualize the structures and shapes of atoms and molecules. Skeletal Model Simpler two-dimensional representations of chemical compounds are accomplished using skeletal models. The illustration shows only the molecular framework or bonds without explicitly showing the atoms. In this representation, many of the carbon atoms... https://www.jove.com/v/11251 120 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58538.jpg Structural Studies of Macromolecules in Solution using Small Angle X-Ray Scattering Here, we present how Small Angle X-Ray Scattering (SAXS) can be utilized to obtain information on low-resolution envelopes representing the macromolecular structures. When used in conjunction with high-resolution structural techniques such as X-Ray Crystallography and Nuclear Magnetic Resonance, SAXS can provide detailed insights into multidomain proteins and macromolecular complexes in-solution. https://www.jove.com/v/58538 439 2018-11-05T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61462.jpg Stability and Structure of Bat Major Histocompatibility Complex Class I with Heterologous β 2 -Microglobulin The protocol describes experimental methods to obtain stable major histocompatibility complex (MHC) class I through potential β2-microglobulin (β2m) substitutions from different species. The structural comparison of MHC I stabilized by homologous and heterologous β2m were investigated. https://www.jove.com/v/61462 677 2021-03-10T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66310.jpg Modeling Ligands into Maps Derived from Electron Cryomicroscopy This protocol introduces the tools available for modeling small-molecule ligands in cryoEM maps of macromolecules. https://www.jove.com/v/66310 570 2024-07-19T20:00:00+00:00 JoVE no https://visualize.jove.com/12852176-artificial-life-and-speciation-a-case-study-heterochromatin-and-speciation-in-the-microtus-savii-group-rodentia-arvicolinae monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/184.jpg Harvesting Sperm and Artificial Insemination of Mice This protocol demonstrates methods for extracting sperm from the testes of males and then inseminating female mice. This procedure is useful when precise time is needed in developmental studies as well as transgenic work. https://www.jove.com/v/184 600 2007-04-28T07:00:00+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/10955/10955_article_thumb_10955.jpg Formation of Species Speciation describes the formation of one or more new species from one or sometimes multiple original species. The resulting species are discrete from the parent species, and barriers to reproduction will typically exist. There are two primary mechanisms, speciation with and without geographic isolation—allopatric and sympatric speciation, respectively.Allopatric SpeciationIn allopatric speciation, gene flow between two populations of the same species is prevented by a geographic barrier, like... https://www.jove.com/v/10955 91 2026-06-01T13:28:05+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/10956/10956_article_thumb_10956.jpg Speciation Rates Speciation can proceed at markedly different rates, and evolutionary biologists commonly describe these differences through the models of gradualism and punctuated equilibrium. Both patterns explain how new species arise, but they differ in the tempo and continuity of evolutionary change. In both cases, evolutionary change arises from heritable variation within populations, with natural selection often shaping traits that improve survival and reproduction under specific environmental conditions. https://www.jove.com/v/10956 67 2026-06-01T13:28:10+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/11126/11126_article_thumb_11126.jpg Genetics of Speciation Speciation is the evolutionary process resulting in the formation of new, distinct species—groups of reproductively isolated populations.The genetics of speciation involves the different traits or isolating mechanisms preventing gene exchange, leading to reproductive isolation. Reproductive isolation can be due to reproductive barriers that have effects either before or after the formation of a zygote. Pre-zygotic mechanisms prevent fertilization from occurring, and post-zygotic mechanisms... https://www.jove.com/v/11126 136 2026-06-01T13:28:06+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/11127/11127_article_thumb_11127.jpg Hybrid Zones Hybrid zones are narrow regions where two closely related species interact, mate, and produce hybrids. Relative to either parent species, hybrids may possess distinct phenotypic or genetic differences that impact their survival and reproductive success. The genetic variances introduced by hybridization influence species diversity and speciation processes within the hybrid zone.Gene flow and natural selection are evolutionary mechanisms that shape the outcome of a hybrid zone. Gene flow... https://www.jove.com/v/11127 149 2026-06-01T13:27:52+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/11131/11131_article_thumb_11131.jpg The Evidence for Evolution Genetic variations accumulating within populations over generations give rise to biological evolution. Evolutionary changes can result in the formation of novel varieties and entire new species. These changes are responsible for the diverse forms of life inhabiting the planet. The evidence for evolution suggests that all living organisms descended from common ancestors.The collection of fossils within sedimentary rocks give a record of common ancestry and often depicts the history of evolution. https://www.jove.com/v/11131 175 2026-06-01T13:28:15+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40722/40722_article_thumb_40722.jpg Evolution of New Traits in Microbes Microorganisms evolve rapidly due to their large population sizes and short generation times, often exhibiting measurable changes within days under laboratory conditions. Natural selection acts on standing genetic variation, enabling the retention and amplification of beneficial traits that confer fitness advantages in changing environments.Adaptive Pigment Regulation in RhodobacterIn Rhodobacter, a genus of purple non-sulfur bacteria, light-harvesting pigments such as bacteriochlorophyll and... https://www.jove.com/v/40722 84 2026-03-12T20:57:34+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63737.jpg Mass-Rearing and Molecular Studies in Tortricidae Pest Insects The present protocol describes the rearing method of tortricid pest insects in the laboratories. The procedures to distinguish insects' sex and extract nucleic acids for high throughput sequencing are established using two tortricid pests. https://www.jove.com/v/63737 382 2022-03-25T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66475.jpg Dissection, Histological Processing, and Gene Expression Analysis of Murine Supraclavicular Brown Adipose Tissue Here, we provide a practical procedure for dissecting and performing histological and gene expression analyses of murine supraclavicular brown adipose tissue. https://www.jove.com/v/66475 410 2024-03-29T21:10:00+00:00 JoVE no https://visualize.jove.com/12876447-modeling-high-resolution-broadband-discourse-in-complex-adaptive-systems monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16100.jpg State Space Representation The frequency-domain technique, commonly used in analyzing and designing feedback control systems, is effective for linear, time-invariant systems. However, it falls short when dealing with nonlinear, time-varying, and multiple-input multiple-output systems. The time-domain or state-space approach addresses these limitations by utilizing state variables to construct simultaneous, first-order differential equations, known as state equations, for an nth-order system. Consider an RLC circuit, a... https://www.jove.com/v/16100 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18072.jpg Modeling and Similitude Scaled modeling is a fundamental technique in engineering, enabling the study of large and complex systems by creating smaller, manageable replicas that recreate critical characteristics of the original. In hydrology and civil infrastructure, for example, scaled models of dams help analyze water flow, turbulence, and pressure. This method allows for accurate predictions of real-world behavior within a controlled environment, significantly reducing the cost and time involved in full-scale... https://www.jove.com/v/18072 72 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18073.jpg Typical Model Studies Fluid mechanics model studies often utilize scaled-down systems to predict fluid behavior in full-scale environments, such as river flows, dam spillways, and structures interacting with open surfaces. Maintaining Froude number similarity in river models is crucial, as it replicates surface flow features like wave patterns and velocities. Practical constraints, however, can introduce geometric distortions, impacting how accurately these models represent the real system. Adjustments, such as... https://www.jove.com/v/18073 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18627.jpg Modeling in Therapy Modeling, a key technique in therapy, uses observational learning to help clients acquire and practice new skills by watching therapists demonstrate desired behaviors. This approach, rooted in Albert Bandura's concept of vicarious learning, plays a significant role in therapeutic interventions for various psychological conditions, including social anxiety, ADHD, and depression. Participant Modeling Participant modeling involves therapists demonstrating calm and effective behaviors in situations... https://www.jove.com/v/18627 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/19878/19878_article_thumb_19878.jpg Social Foundations of Self IV: Self in Digital Communication Since the early 2000s, computer-mediated communication (CMC) has grown rapidly, playing a crucial role in self-development. A key distinction between CMC and real-life interactions is the lack of a physically present partner. This absence makes non-verbal cues such as facial expressions, body language, and paralinguistic signals unavailable in CMC platforms like email, instant messaging, or social media. The lack of these cues can create ambiguity and complicate how feedback is interpreted.The... https://www.jove.com/v/19878 90 2025-09-18T17:24:23+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40598/40598_article_thumb_40598_TN.jpg Modeling with Differential Equations Population dynamics can be described mathematically by considering the population size P(t) as a function of time. The rate of change of the population is then represented by the derivative of P(t). A simple assumption is that the rate of growth is proportional to the size of the population itself. This leads to an exponential growth model, where the population increases rapidly without bound. While this is a useful first approximation, it does not reflect realistic long-term... https://www.jove.com/v/40598 85 2026-01-12T20:24:36+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53285.jpg Visualizing Hyporheic Flow Through Bedforms Using Dye Experiments and Simulation This manuscript describes how to create regular bedforms in a flume, visualize flow through the bedforms, and use computer simulations to simulate the hyporheic flow. The computer simulations compare well with the experimental observations. This coupled simulation and experiment is well-suited for both research and educational purposes. https://www.jove.com/v/53285 589 2015-11-18T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58719.jpg The HoneyComb Paradigm for Research on Collective Human Behavior Here, we present the computer-based, multi-agent game HoneyComb, which enables experimental investigations of collective human movement behavior via black-dot-avatars on a virtual 2D hexagonal playfield. Different experimental conditions, like variable incentives on goal fields or vision radius, can be set, and their effects on human movement behavior can be investigated. https://www.jove.com/v/58719 408 2019-01-19T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60331.jpg Multimodal Protocol for Assessing Metacognition and Self-Regulation in Adults with Learning Difficulties The current work proposes a multimodal evaluation protocol focused on metacognitive, self-regulation of learning, and emotional processes, which make up the basis of the difficulties in adults with LDs. https://www.jove.com/v/60331 775 2020-09-27T19:30:00+00:00 JoVE no https://visualize.jove.com/12879675-use-of-the-internet-for-patient-care-a-nationwide-survey-of-australian-anaesthetists monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12958.jpg Current Trends in Nursing II Trends in nursing are multifactorial and associated with changes in society, within the nursing profession, and in other professions. Notably, telehealth and remote nursing contribute to successful healthcare delivery for numerous patients and help reduce stress for nurses due to nursing shortages. Nurses can reach patients, monitor their conditions, and interact with them using computers, audio, visual accessories, and telephones—for example, remote patient monitoring systems. Likewise,... https://www.jove.com/v/12958 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12979.jpg Issues And Trends In Healthcare Delivery System The issues and trends in healthcare delivery are constantly changing. The COVID-19 pandemic is one recent issue that wreaked havoc on healthcare systems, causing a shortage of healthcare workers, high demand for medicines and supplies, and increased medical expenditure due to a lack of insurance. Other issues include rising healthcare costs and care fragmentation. Cost Containment Payment for healthcare services has historically promoted adoption of costly and often unnecessary or inefficient... https://www.jove.com/v/12979 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14116.jpg Guidelines and Strategies for Safe Computer Charting The guidelines and strategies provided by the American Nurses Association (ANA) and the Canadian Nurses Association (CNA) offer essential principles for ensuring safe and secure computer charting systems in healthcare settings. Let's break down each recommendation: Maintain Confidentiality and Security: • Never share computer signatures or passwords with anyone, including colleagues or float nurses, to prevent unauthorized access to patient records. • Always log out of computer terminals... https://www.jove.com/v/14116 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14748.jpg Local Anesthetics: Clinical Application as Epidural Anesthesia Epidural anesthetics are administered in the fat-filled epidural space, the outermost part of the spinal canal. This technique is commonly employed for pain management and anesthesia during lower abdomen and pelvis surgeries or labor and delivery. Since epidural anesthetics can be infused through an epidural catheter, all types of drugs, including short-acting ones, can be administered. Chloroprocaine and lidocaine are examples of short and long-duration anesthetics, respectively. Bupivacaine... https://www.jove.com/v/14748 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14749.jpg Local Anesthetics: Clinical Application as Intravenous Regional Anesthesia Intravenous regional anesthesia or the Bier block technique is used to anesthetize a specific limb or extremity. It uses exsanguinated or blood-drained vessels to transport local anesthetics or LAs to the peripheral nerve trunks. Lidocaine without vasoconstrictors like epinephrine is most commonly used for this technique. Other drugs used are prilocaine, ropivacaine, and chloroprocaine. Bupivacaine is not recommended for this technique due to its high cardiac toxicity. One of the advantages of... https://www.jove.com/v/14749 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15188.jpg General Anesthesia: Overview Anesthesia is a medical procedure that uses drugs for CNS suppression to enable painless surgeries and procedures. The selection of anesthetics is influenced by their pharmacokinetic properties, side effects, and patient characteristics. Various types of anesthesia include general, local, regional, spinal, and inhalational. General anesthesia induces unconsciousness in the whole body, while the others target specific areas or sensations. It is administered to minimize adverse effects, maintain... https://www.jove.com/v/15188 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55116.jpg Topical Airway Anesthesia for Awake-endoscopic Intubation Using the Spray-as-you-go Technique with High Oxygen Flow The topical anesthetic lidocaine was atomized using a high oxygen flow through the working channel of a flexible intubating endoscope to achieve topical airway anesthesia for awake endotracheal intubation. We prefer this modified spray-as-you-go technique for endoscopic intubation to classical bolus application because of higher patient satisfaction and better compliance. https://www.jove.com/v/55116 343 2017-01-13T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56881.jpg Recording Brain Electromagnetic Activity During the Administration of the Gaseous Anesthetic Agents Xenon and Nitrous Oxide in Healthy Volunteers Simultaneous magnetoencephalography and electroencephalography provides a useful tool to search for common and distinct macro-scale mechanisms of reductions in consciousness induced by different anesthetics. This paper illustrates the empirical methods underlying the recording of such data from healthy humans during N-Methyl-D-Aspartate-(NMDA)-receptor-antagonist-based anesthesia during inhalation of nitrous oxide and xenon. https://www.jove.com/v/56881 892 2018-01-13T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58798.jpg E-Patient Counseling Trial (E-PACO): Computer Based Education versus Nurse Counseling for Patients to Prepare for Colonoscopy The aim of this trial is to establish the position of online computer-based education as a tool for patient preparation prior to a colonoscopy. Computer based education is compared with the standard of care, nurse counseling, evaluating endoscopic quality measures and patient related outcome measures. https://www.jove.com/v/58798 388 2019-08-01T19:30:00+00:00 JoVE no https://visualize.jove.com/12890135-software-reuse-reference-model-approach-in-developing-an-automated-medical-information-system-amis-for-improving-health-care-practice monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12979.jpg Issues And Trends In Healthcare Delivery System The issues and trends in healthcare delivery are constantly changing. The COVID-19 pandemic is one recent issue that wreaked havoc on healthcare systems, causing a shortage of healthcare workers, high demand for medicines and supplies, and increased medical expenditure due to a lack of insurance. Other issues include rising healthcare costs and care fragmentation. Cost Containment Payment for healthcare services has historically promoted adoption of costly and often unnecessary or inefficient... https://www.jove.com/v/12979 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14110.jpg Methods of Documentation II: POMR The Problem-Oriented Medical Record (POMR) revolutionized medical record-keeping by introducing a systematic approach focusing on the patient's problems rather than merely listing symptoms. Dr. Lawrence Weed's introduction of this method in the 1960s marked a significant advancement in medical documentation. The POMR framework consists of four key components: the database, problem list, plan of care, and progress notes. Database: This section documents crucial medical information about the... https://www.jove.com/v/14110 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14114.jpg Methods of Documentation VI: Case Management Model The case management model is a multidisciplinary approach that involves healthcare professionals from diverse disciplines, such as physicians, nurses, therapists, social workers, and pharmacists, working collaboratively to address the various needs of patients. Each healthcare professional brings unique expertise and perspectives, contributing to a more comprehensive understanding of the patient's condition and tailoring treatment plans accordingly. For example, a patient with a chronic illness... https://www.jove.com/v/14114 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14115.jpg Methods of Documentation VII: EMR Electronic Medical Records (EMRs) primarily center around electronically documenting patients' health information within a single healthcare organization or practice. They contain essential clinical data related to a patient's medical history, diagnoses, medications, treatment plans, lab results, and other pertinent information relevant to the specific encounter or episode of care. EMRs are designed to streamline documentation and workflow processes within individual healthcare settings,... https://www.jove.com/v/14115 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14125.jpg Health Information Technology and Healthcare Information System Health Information Technology (HIT) Health Information Technology, commonly called HIT, integrates advanced information systems and technology in healthcare settings. Its primary functions include: Documentation and Monitoring of Patient Care: HIT systems facilitate the efficient recording and tracking of patient data, aiding healthcare providers in monitoring patients' health status and making informed decisions. Managerial and Organizational Functions: Beyond patient care, HIT is... https://www.jove.com/v/14125 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14126.jpg Nursing Clinical Information System Nursing Clinical Information System (NCIS) A Nursing Clinical Information System (NCIS) is a specialized type of healthcare information system tailored to meet the unique needs of nursing practice. It incorporates the principles of nursing informatics to streamline information management and improve the quality of care delivery. Critical attributes of NCIS include: Efficient Information Management: NCIS is designed to manage patient information efficiently, making it easily accessible to... https://www.jove.com/v/14126 87 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58392.jpg A Metadata Extraction Approach for Clinical Case Reports to Enable Advanced Understanding of Biomedical Concepts We present a protocol and associated metadata template for the extraction of text describing biomedical concepts in clinical case reports. The structured text values produced through this protocol can support deep analysis of thousands of clinical narratives. https://www.jove.com/v/58392 470 2018-09-20T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61899.jpg Digital Home-Monitoring of Patients after Kidney Transplantation: The MACCS Platform The MACCS platform is a comprehensive telemedicine concept aiming at better outcomes after kidney transplantation by sharing key medical information between patients and physicians. A telemedicine team reviews incoming data to detect potential complications and to improve adherence in kidney transplant recipients to achieve better long-term outcomes. https://www.jove.com/v/61899 433 2021-04-12T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68270.jpg Introduction of an Integrated Pathology Image Management, Artificial Intelligence, and Reporting System Integrated image management, artificial intelligence (AI), and reporting systems have revolutionized diagnostic pathology practice. In this paper, we introduce FlexLIS, a state-of-the-art system that enables AI to assist pathologists in performing histopathology image assessments and generating diagnostic reports. https://www.jove.com/v/68270 333 2025-07-11T22:40:00+00:00 JoVE no https://visualize.jove.com/12926544-influence-of-aida-on-certain-behaviors-in-rats-subjected-to-experimental-hypoxia monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/52527.jpg Delivery of In Vivo Acute Intermittent Hypoxia in Neonatal Rodents to Prime Subventricular Zone-derived Neural Progenitor Cell Cultures This article describes the methodology for administering short periods of intermittent hypoxia to postnatal day 1-8 mouse or rat pups. This approach effectively elicits a robust tissue level “priming effect” on cultured neural progenitor cells that are harvested within 30 min of hypoxia exposure. https://www.jove.com/v/52527 345 2015-11-02T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65784.jpg Acupuncture Treatment in a Mouse Model of Chronic Hypoxia-Induced Cognitive Dysfunction Here, we describe a protocol for implementing mild anesthesia and acupuncture treatment on a chronic hypoxia mouse model and conducting behavioral tests to assess the cognitive alterations post-treatment. https://www.jove.com/v/65784 206 2023-12-08T21:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68435.jpg Hypoxia Alters miRNAs Levels Involved in Non-Mendelian Inheritance of Autism Spectrum Disorder in Mice Here, we present a protocol to induce hypoxia in neonatal mice by delivering them in controlled environments with varying oxygen concentrations. Mouse models subjected to oxygen variations at birth have durably varied the expression of miRNAs involved in the induction of behavioral phenotypic changes such as autism. https://www.jove.com/v/68435 553 2025-07-11T20:20:00+00:00 JoVE no https://visualize.jove.com/12944532-alternative-to-hand-tuning-conductance-based-models-construction-and-analysis-of-databases-of-model-neurons monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16586.jpg Mechanistic Models: Compartment Models in Algorithms for Numerical Problem Solving Mechanistic models play a crucial role in algorithms for numerical problem-solving, particularly in nonlinear mixed effects modeling (NMEM). These models aim to minimize specific objective functions by evaluating various parameter estimates, leading to the development of systematic algorithms. In some cases, linearization techniques approximate the model using linear equations. In individual population analyses, different algorithms are employed, such as Cauchy's method, which uses a... https://www.jove.com/v/16586 89 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63792.jpg Computational Modeling of Retinal Neurons for Visual Prosthesis Research - Fundamental Approaches We summarize a workflow to computationally model a retinal neuron's behaviors in response to electrical stimulation. The computational model is versatile and includes automation steps that are useful in simulating a range of physiological scenarios and anticipating the outcomes of future in vivo/in vitro studies. https://www.jove.com/v/63792 650 2022-06-21T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67833.jpg Identification and Classification of Position-specific GABA A Receptor Subunit Missense Variants for Their Role In Hippocampal Pyramidal Neurons This study introduces a multiscale framework, spanning from DNA to protein function and neural behavior. It presents a novel approach for investigating predicted pathogenic mutations in the GABAA receptor subunit, hypothesizing that epileptogenic mutations and proximal mutations, predicted as pathogenic, may produce similar effects on the CA1 pyramidal neuron model. https://www.jove.com/v/67833 484 2025-06-06T20:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/69155.jpg Dynamic Clamp Methods to Investigate Impaired Neuronal Excitability Associated with Autism Dynamic clamp electrophysiology can establish causal links between neuronal firing deficits and ion channel dysfunction. We describe dynamic clamp methods and protocols in mouse cerebellar Purkinje neurons, noting useful resources and technical considerations. In a representative study, we add modeled sodium conductance to Tsc1-/- Purkinje neurons to rescue repetitive firing. https://www.jove.com/v/69155 524 2025-10-17T21:20:00+00:00 JoVE no https://visualize.jove.com/12945940-canadian-association-of-neuroscience-review-development-and-plasticity-of-the-auditory-cortex monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10853.jpg Hearing When we hear a sound, our nervous system is detecting sound waves—pressure waves of mechanical energy traveling through a medium. The frequency of the wave is perceived as pitch, while the amplitude is perceived as loudness. Sound waves are collected by the external ear and amplified as they travel through the ear canal. When sounds reach the junction between the outer and middle ear, they vibrate the tympanic membrane—the eardrum. The resulting mechanical energy causes the attached ossicles—a... https://www.jove.com/v/10853 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14970.jpg Auditory Pathway Auditory pathways constitute the complex neural circuits responsible for transmitting and interpreting auditory information from the peripheral auditory system to the brain. Sound waves are initially captured by the outer ear, funneled through the ear canal, and reach the tympanic membrane (eardrum). These vibrations are transmitted via the middle ear's ossicles to the inner ear's cochlea. When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking the... https://www.jove.com/v/14970 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17745.jpg Neuroplasticity Neuroplasticity reflects the brain's remarkable capacity to adapt and evolve, responding dynamically to learning, experiences, or injury by reorganizing its neural circuitry. This reorganization involves creating new neural connections and refining old ones through a series of biological processes that contribute to the brain's lifelong development and adaptability. • The brain's ability to change begins with the growth of dendrites and axons, which effectively increases the structural... https://www.jove.com/v/17745 61 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17771.jpg Auditory Perception The auditory system is essential for sound perception, utilizing various critical structures. When sound waves enter the outer ear, they travel through the ear canal and cause the eardrum to vibrate. These vibrations are then transmitted to the middle ear, where three tiny bones – the malleus, incus, and stapes – amplify the sound. This amplification is crucial, as it ensures that the sound vibrations are strong enough to be conveyed to the inner ear. These vibrations then reach the cochlea, a... https://www.jove.com/v/17771 77 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53067.jpg Modification of a Colliculo-thalamocortical Mouse Brain Slice, Incorporating 3-D printing of Chamber Components and Multi-scale Optical Imaging Using multiple angles to cut the mouse pup brain, we improve upon a previously-described acute brain slice which captures the connections between most of the major auditory midbrain and forebrain structures. https://www.jove.com/v/53067 365 2015-09-18T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56429.jpg Stereotactically-guided Ablation of the Rat Auditory Cortex, and Localization of the Lesion in the Brain We describe a method for the stereotactically-guided location, exposure, and ablation of the auditory cortex in rats. The localization of the ablation is assessed using a coordinate map postmortem. https://www.jove.com/v/56429 569 2017-10-11T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64737.jpg Semi-Automated Analysis of Peak Amplitude and Latency for Auditory Brainstem Response Waveforms Using R This article describes the semi-automated measurement of the amplitudes and latencies of the first five peaks and troughs in the auditory brainstem response waveform. An additional routine compiles and annotates the data into a spreadsheet for experimenter analysis. These free computer routines are executed using the open-source statistical package R. https://www.jove.com/v/64737 361 2022-12-09T22:20:00+00:00 JoVE no https://visualize.jove.com/12953294-mri-based-morphometric-of-typical-and-atypical-brain-development monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17752.jpg Brain Imaging Brain imaging technologies provide critical insights into both the structure and function of the human brain, enabling medical professionals and researchers to diagnose, study, and treat neurological disorders or psychiatric disorders more effectively. These technologies include computerized axial tomography (CAT or CT scans), positron-emission tomography (PET scans), magnetic resonance imaging (MRI), functional magnetic resonance imaging (fMRI), and Transcranial Magnetic Stimulation (TMS).<br... https://www.jove.com/v/17752 74 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57256.jpg Whole-brain Segmentation and Change-point Analysis of Anatomical Brain MRI—Application in Premanifest Huntington's Disease This paper describes a statistical model for volumetric MRI data analysis, which identifies the "change-point" when brain atrophy begins in premanifest Huntington's disease. Whole-brain mapping of the change-points is achieved based on brain volumes obtained using an atlas-based segmentation pipeline of T1-weighted images. https://www.jove.com/v/57256 546 2018-06-09T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60881.jpg Brain Morphology of Cannabis Users With or Without Psychosis: A Pilot MRI Study This is a 3T magnetic resonance imaging study aiming to investigate grey matter volume differences between cannabis-induced psychosis patients and non-psychotic chronic cannabis users. https://www.jove.com/v/60881 450 2020-08-18T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65180.jpg Micro-CT Imaging and Morphometric Analysis of Mouse Neonatal Brains This study describes the steps for obtaining high-resolution images of neonatal mouse brains by combining micro-computed tomography (micro-CT) and a contrast agent in ex vivo samples. We describe basic morphometric analyses to quantify brain size and shape in these images. https://www.jove.com/v/65180 396 2023-05-19T21:00:00+00:00 JoVE no https://visualize.jove.com/12958081-unexpected-amnesia-are-there-lessons-to-be-learned-from-cases-of-amnesia-following-unilateral-temporal-lobe-surgery monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4411.jpg Investigations on Alterations of Hippocampal Circuit Function Following Mild Traumatic Brain Injury A multi-faceted approach to investigating functional changes to hippocampal circuitry is explained. Electrophysiological techniques are described along with the injury protocol, behavioral testing and regional dissection method. The combination of these techniques can be applied in similar fashion for other brain regions and scientific questions. https://www.jove.com/v/4411 659 2012-11-19T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14944.jpg Higher Mental Functions of Brain: Learning and Memory Memory is one of the most vital higher mental functions of the brain. Memory is closely related to learning because it enables us to retain information and experiences from our past to use them in our present life. It also helps us to remember facts, events, and skills, such as riding a bike or swimming. There are two types of memory — declarative memory, which involves memorizing facts or events, and procedural memory, which enables us to remember how to do something like writing or playing an... https://www.jove.com/v/14944 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18182.jpg Traumatic Memory Emotionally traumatic events often lead to memories that are exceptionally vivid and enduring, sometimes persisting with remarkable clarity throughout an individual's life. A classic example of this phenomenon is a person who survives a car accident. Even years later, they may recall every detail of the event with startling accuracy — the screeching of the tires, the jarring impact, and the acrid smell of burning rubber. Such vividness contrasts sharply with how an individual remembers mundane... https://www.jove.com/v/18182 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18186.jpg Role of Hippocampus in Memory The hippocampus, a critical brain structure, plays an essential role in memory processing, particularly in the formation and retrieval of memory. This small, seahorse-shaped region is located within the medial temporal lobe, with one hippocampus in each brain hemisphere. Experimental studies involving lesions in the hippocampi of rats have demonstrated significant impairments in tasks such as object recognition and maze navigation, indicating the hippocampus involvement in both recognition and... https://www.jove.com/v/18186 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18196.jpg Amnesia Amnesia is a condition marked by long-term memory loss, which impairs the ability to recall past events or create new memories. The severity and duration of memory loss vary depending on the type and underlying cause. Amnesia is classified into two main types: retrograde and anterograde. Retrograde amnesia is marked by the loss of memories formed before the onset of the condition. Patients may recall distant past events but often forget those occurring shortly before the incident. Anterograde... https://www.jove.com/v/18196 73 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/19601.jpg Dissociative Amnesia Dissociative amnesia is a complex psychological condition that manifests as an inability to recall personal information, often tied to traumatic or stressful events. Unlike general amnesia, individuals with this condition retain the ability to perform routine activities and procedural tasks, such as operating a phone or navigating public transportation, yet experience profound gaps in autobiographical memory. These lapses may encompass significant life events, such as suicide attempts or... https://www.jove.com/v/19601 81 JoVE no https://cloudfront.jove.com/files/ftp_upload/40929/40929_article_thumb_40929.jpg Traumatic Brain Injury l: Introduction DefinitionTraumatic brain injury, or TBI, is a disturbance of normal brain function induced by an external mechanical force, such as a direct blow to the head or a penetrating injury. It can affect both brain structure and function, producing a wide range of clinical outcomes. TBI is a heterogeneous condition, meaning its effects may differ based on the type, location, and severity of the injury.Basis of ClassificationTBI is classified based on severity, injury mechanism, or pathophysiology. In... https://www.jove.com/v/40929 88 2026-04-13T23:56:05+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56694.jpg Utilizing the Modified T-Maze to Assess Functional Memory Outcomes After Cardiac Arrest This protocol describes the use of a modified T-maze to evaluate functional learning/memory in asphyxia cardiac arrest-induced cerebral ischemia. https://www.jove.com/v/56694 422 2018-01-05T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67658.jpg Anteromesial Temporal Lobectomy for Medically Intractable Temporal Lobe Epilepsy: An Operative Study Here we provide an overview of the anteromesial temporal lobectomy procedure, used in the treatment of patients with medically refractory temporal lobe epilepsy. In particular, we describe herein, the details of the operative method and related surgical technique, in addition to summarizing the indications and outcomes of the procedure. https://www.jove.com/v/67658 689 2025-08-15T19:40:00+00:00 JoVE no https://visualize.jove.com/13829382-feeding-behavior-and-electrical-stimulation-of-the-brain-of-carassius-auratus monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/53002.jpg Combined Shuttle-Box Training with Electrophysiological Cortex Recording and Stimulation as a Tool to Study Perception and Learning Shuttle-box avoidance learning is well-established in behavioral neuroscience. This protocol describes how shuttle-box learning in rodents can be combined with site-specific electrical intracortical microstimulation (ICMS) and simultaneous chronical in vivo recordings as a tool to study multiple aspects of learning and perception. https://www.jove.com/v/53002 523 2015-10-22T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56242.jpg Transcranial Electrical Brain Stimulation in Alert Rodents This protocol describes a surgical set-up for a permanent epicranial electrode socket and an implanted chest electrode in rodents. By placing a second electrode into the socket, different types of transcranial electrical brain stimulation can be delivered to the motor system in alert animals through the intact skull. https://www.jove.com/v/56242 608 2017-11-02T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64113.jpg Using a Bipolar Electrode to Create a Temporal Lobe Epilepsy Mouse Model by Electrical Kindling of the Amygdala The amygdala plays a key role in temporal lobe epilepsy, which originates in and propagates from this structure. This article provides a detailed description of the fabrication of deep brain electrodes with both recording and stimulating functions. It introduces a model of medial temporal lobe epilepsy originating from the amygdala. https://www.jove.com/v/64113 589 2022-06-29T14:30:00+00:00 JoVE no https://visualize.jove.com/14107435-visual-problem-solving-in-a-bottlenose-dolphin monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1742.jpg Using the optokinetic response to study visual function of zebrafish Optokinetic response has been widely used to assess the visual functions of larval zebrafish. Nevertheless, the standard protocol for larval fish is not yet readily applicable in adults1-5. Here, we introduce how to measure the OKR of adult zebrafish using a new protocol which is established in our lab. https://www.jove.com/v/1742 539 2010-02-03T02:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/3556.jpg VisioTracker, an Innovative Automated Approach to Oculomotor Analysis The VisioTracker is an automated system for the quantitative analysis of visual performance of larval and small adult fish based on the recording of eye movements. It features full control over visual stimulus properties and real-time analysis, enabling high-throughput research in fields such as visual system development and function, pharmacology, neural circuit studies and sensorimotor integration. https://www.jove.com/v/3556 351 2011-10-12T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50832.jpg The Optokinetic Response as a Quantitative Measure of Visual Acuity in Zebrafish Zebrafish have been a valuable tool for many research areas. Here we demonstrate a method to elicit a visual response and calculate a functional visual acuity in the adult zebrafish. https://www.jove.com/v/50832 296 2013-10-10T05:00:00+00:00 JoVE no https://visualize.jove.com/14503522-top-level-modeling-of-an-als-system-utilizing-object-oriented-techniques monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3358.jpg Creating Objects and Object Categories for Studying Perception and Perceptual Learning We describe a novel methodology for creating naturalistic 3-D objects and object categories with precisely defined feature variations. We use simulations of the biological processes of morphogenesis and phylogenesis to create novel, naturalistic virtual 3-D objects and object categories that can then be rendered as visual images or haptic objects. https://www.jove.com/v/3358 878 2012-11-02T22:00:00+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/15786/15786_article_thumb_15786.jpg A Single-Component System In the field of chemistry, the terms "component" and "phase" hold significant importance. A component refers to a chemically distinct substance in a system that has specific properties. It is chemically homogeneous, meaning it has the same properties throughout. For example, in a mixture of salt and water, both salt and water are considered separate components because they have different chemical properties.On the other hand, a phase is a form of matter that has a consistent chemical... https://www.jove.com/v/15786 84 2026-02-26T21:04:34+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16584.jpg Mechanistic Models: Overview of Compartment Models Mechanistic models, a category encompassing both physiological and compartmental modeling, differ from empirical models' approaches to incorporating known factors about the systems being modeled. Empirical models describe data with minimal assumptions, while mechanistic models aim to provide a robust description of available data by specifying assumptions and integrating known factors about the system. Compartmental analysis is a key example of a mechanistic model in pharmacokinetics and... https://www.jove.com/v/16584 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16586.jpg Mechanistic Models: Compartment Models in Algorithms for Numerical Problem Solving Mechanistic models play a crucial role in algorithms for numerical problem-solving, particularly in nonlinear mixed effects modeling (NMEM). These models aim to minimize specific objective functions by evaluating various parameter estimates, leading to the development of systematic algorithms. In some cases, linearization techniques approximate the model using linear equations. In individual population analyses, different algorithms are employed, such as Cauchy's method, which uses a... https://www.jove.com/v/16586 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18072.jpg Modeling and Similitude Scaled modeling is a fundamental technique in engineering, enabling the study of large and complex systems by creating smaller, manageable replicas that recreate critical characteristics of the original. In hydrology and civil infrastructure, for example, scaled models of dams help analyze water flow, turbulence, and pressure. This method allows for accurate predictions of real-world behavior within a controlled environment, significantly reducing the cost and time involved in full-scale... https://www.jove.com/v/18072 72 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18627.jpg Modeling in Therapy Modeling, a key technique in therapy, uses observational learning to help clients acquire and practice new skills by watching therapists demonstrate desired behaviors. This approach, rooted in Albert Bandura's concept of vicarious learning, plays a significant role in therapeutic interventions for various psychological conditions, including social anxiety, ADHD, and depression. Participant Modeling Participant modeling involves therapists demonstrating calm and effective behaviors in situations... https://www.jove.com/v/18627 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/40598/40598_article_thumb_40598_TN.jpg Modeling with Differential Equations Population dynamics can be described mathematically by considering the population size P(t) as a function of time. The rate of change of the population is then represented by the derivative of P(t). A simple assumption is that the rate of growth is proportional to the size of the population itself. This leads to an exponential growth model, where the population increases rapidly without bound. While this is a useful first approximation, it does not reflect realistic long-term... https://www.jove.com/v/40598 85 2026-01-12T20:24:36+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59151.jpg A Rapid Method for Modeling a Variable Cycle Engine Here, we present a protocol to build a component-level mathematical model for a variable cycle engine. https://www.jove.com/v/59151 298 2019-08-13T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63792.jpg Computational Modeling of Retinal Neurons for Visual Prosthesis Research - Fundamental Approaches We summarize a workflow to computationally model a retinal neuron's behaviors in response to electrical stimulation. The computational model is versatile and includes automation steps that are useful in simulating a range of physiological scenarios and anticipating the outcomes of future in vivo/in vitro studies. https://www.jove.com/v/63792 650 2022-06-21T20:00:00+00:00 JoVE no https://visualize.jove.com/14519642-artificial-intelligence-in-predicting-bladder-cancer-outcome-a-comparison-of-neuro-fuzzy-modeling-and-artificial-neural-networks monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/59101.jpg Magnetic Resonance Imaging Assessment of Carcinogen-induced Murine Bladder Tumors Murine bladder tumors are induced with the N-butyl-N-(4-hydroxybutyl) nitrosamine carcinogen (BBN). Bladder tumor generation is heterogeneous; therefore, an accurate assessment of tumor burden is needed before randomization to experimental treatment. Here we present a fast, reliable MRI protocol to assess tumor size and stage. https://www.jove.com/v/59101 319 2019-03-29T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67941.jpg Comparison of Predictive Performance of Three Lymph Node Staging Systems in Colorectal Signet Ring Cell Carcinoma Based on Machine Learning Model This study evaluates prognostic systems for colorectal signet-ring cell carcinoma patients using machine learning models and competing risk analyses. It identifies log odds of positive lymph nodes as a superior predictor compared to pN staging, demonstrating strong predictive performance and aiding clinical decision-making through robust survival prediction tools. https://www.jove.com/v/67941 433 2025-04-18T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68270.jpg Introduction of an Integrated Pathology Image Management, Artificial Intelligence, and Reporting System Integrated image management, artificial intelligence (AI), and reporting systems have revolutionized diagnostic pathology practice. In this paper, we introduce FlexLIS, a state-of-the-art system that enables AI to assist pathologists in performing histopathology image assessments and generating diagnostic reports. https://www.jove.com/v/68270 333 2025-07-11T22:40:00+00:00 JoVE no https://visualize.jove.com/14535219-acute-complications-of-artificial-airways monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16351.jpg Acute Respiratory Failure-III Hypercapnic respiratory failure, also known as Type 2 or ventilatory respiratory failure, is a severe condition characterized by the body's inability to effectively remove carbon dioxide (CO2) from the bloodstream. It leads to an arterial CO2 pressure (PaCO2) exceeding 45 mmHg and a blood pH above 7.35. This situation indicates that the body's ventilatory demand, or the ventilation needed to maintain normal PaCO2 levels, surpasses its supply or the maximum gas flow achievable without causing... https://www.jove.com/v/16351 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16362.jpg Asthma-III: Symptoms and Complications Asthma, a common chronic respiratory condition, is classified considering the frequency and severity of symptoms alongside lung function impairment. Understanding this classification is essential for appropriate treatment and management. Here's a detailed look at the classification of asthma and its clinical features and complications: Classification of Asthma Intermittent Asthma: Symptoms occur fewer than twice a week. Night-time awakenings due to asthma occur fewer than twice a month.<br... https://www.jove.com/v/16362 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16397.jpg Endotracheal Tube Extubation Endotracheal tube extubation is a critical procedure in weaning patients from mechanical ventilation. It involves physically removing the oral or nasal endotracheal (ET) tube, marking the final step in liberating a patient from ventilatory support. Procedure Extubation removes the endotracheal tube (ETT) from the patient on mechanical ventilation. It requires a well-coordinated, multidisciplinary approach involving physicians, nurses, respiratory therapists, and other healthcare professionals. https://www.jove.com/v/16397 84 JoVE no https://cloudfront.jove.com/files/ftp_upload/17947/17947_article_thumb_17947.jpg Cardiopulmonary Resuscitation II: ACLS Airway Management Airway management is a key skill in emergency and critical care settings, as maintaining a clear airway is essential for adequate oxygenation and ventilation.Head Tilt-Chin Lift TechniqueThe head tilt-chin lift maneuver is an essential technique primarily used in patients without suspected cervical spine injuries. To perform this maneuver, one hand is placed on the patient’s forehead, and gentle pressure is applied backward to tilt the head. The fingertips of the other hand are positioned under... https://www.jove.com/v/17947 82 2025-06-19T16:38:19+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17950/17950_article_thumb_17950.jpg Cardiopulmonary Resuscitation V: Advanced Airway Management Techniques Airway management is essential in emergency and surgical medicine, ensuring ventilation and oxygenation in patients who cannot maintain their own airway. Clinicians use a range of techniques and devices to secure the airway, depending on the patient’s condition and the clinical context. Key methods include endotracheal intubation, rapid sequence intubation (RSI), supraglottic airway devices, and advanced visualization aids. In cases where these approaches fail, surgical airway interventions are... https://www.jove.com/v/17950 90 2025-06-19T16:39:17+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40971/40971_article_thumb_40971.jpg Atelectasis II: Pathophysiology Atelectasis develops when alveoli lose their air and collapse inward. Because lung tissue is naturally elastic, these air sacs shrink rather than remaining open. Collapsed alveoli are no longer ventilated, reducing their role in gas exchange. Blood flow may continue in these regions, creating a ventilation–perfusion mismatch. Clinical findings include decreased breath sounds, dullness to percussion, reduced chest expansion, and decreased tactile fremitus as sound transmission through collapsed... https://www.jove.com/v/40971 70 2026-04-15T17:50:40+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55116.jpg Topical Airway Anesthesia for Awake-endoscopic Intubation Using the Spray-as-you-go Technique with High Oxygen Flow The topical anesthetic lidocaine was atomized using a high oxygen flow through the working channel of a flexible intubating endoscope to achieve topical airway anesthesia for awake endotracheal intubation. We prefer this modified spray-as-you-go technique for endoscopic intubation to classical bolus application because of higher patient satisfaction and better compliance. https://www.jove.com/v/55116 343 2017-01-13T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59396.jpg Manufacture of a Multi-Purpose Low-Cost Animal Bench-Model for Teaching Tracheostomy This article illustrates every step of the manufacture of a new multi-purpose low-cost animal bench-model for subglottic airway access management. All the procedures are shown in the video. The model's realism and its suitability for training the given clinical maneuvers were assessed by independent senior otolaryngologists and anesthesiologists. https://www.jove.com/v/59396 606 2019-05-18T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63955.jpg Endotracheal Intubation Using a Flexible Intubation Endoscope as a Standardized Model for Safe Airway Management in Swine The use of pigs in research has increased in recent years. Nevertheless, pigs are characterized by difficult airway anatomy. By demonstrating how to perform endoscopically guided endotracheal intubation, the present protocol aims to further increase laboratory animals' safety to avoid animal suffering and unnecessary death. https://www.jove.com/v/63955 270 2022-08-25T20:30:00+00:00 JoVE no https://visualize.jove.com/14538125-applications-of-neural-networks-to-recovery-of-biological-products monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11525.jpg Protein Networks An organism can have thousands of different proteins, and these proteins must cooperate to ensure the health of an organism. Proteins bind to other proteins and form complexes to carry out their functions. Many proteins interact with multiple other proteins creating a complex network of protein interactions. These interactions can be represented through maps depicting protein-protein interaction networks, represented as nodes and edges. Nodes are circles that are representative of a protein,... https://www.jove.com/v/11525 146 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55609.jpg Anatomically Inspired Three-dimensional Micro-tissue Engineered Neural Networks for Nervous System Reconstruction, Modulation, and Modeling This manuscript details the fabrication of micro-tissue engineered neural networks: three-dimensional micron-sized constructs comprised of long aligned axonal tracts spanning aggregated neuronal population(s) encased in a tubular hydrogel. These living scaffolds can serve as functional relays to reconstruct or modulate neural circuitry or as biofidelic test-beds mimicking gray-white matter neuroanatomy. https://www.jove.com/v/55609 645 2017-05-31T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62796.jpg JUMPn: A Streamlined Application for Protein Co-Expression Clustering and Network Analysis in Proteomics We present a systems biology tool JUMPn to perform and visualize network analysis for quantitative proteomics data, with a detailed protocol including data pre-processing, co-expression clustering, pathway enrichment, and protein-protein interaction network analysis. https://www.jove.com/v/62796 448 2021-10-19T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65910.jpg DeepOmicsAE: Representing Signaling Modules in Alzheimer's Disease with Deep Learning Analysis of Proteomics, Metabolomics, and Clinical Data DeepOmicsAE is a workflow centered on the application of a deep learning method (i.e., an autoencoder) to reduce the dimensionality of multi-omics data, providing a foundation for predictive models and signaling modules representing multiple layers of omics data. https://www.jove.com/v/65910 587 2023-12-15T22:00:00+00:00 JoVE no https://visualize.jove.com/14552538-spatial-distribution-of-coefficients-of-asymmetry-of-brain-bioelectrical-activity-during-the-experiencing-of-negative-emotions monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2430.jpg Brain Imaging Investigation of the Neural Correlates of Emotion Regulation We present a protocol that allows investigation of the neural correlates of deliberate and automatic emotion regulation, using functional magnetic resonance imaging. This protocol can be used in healthy participants, both young and older, as well as in clinical patients. https://www.jove.com/v/2430 844 2011-08-26T20:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/2433.jpg Brain Imaging Investigation of the Memory-Enhancing Effect of Emotion We present a protocol that uses functional magnetic resonance imaging to investigate the neural correlates of the memory-enhancing effect of emotion. This protocol allows identification of brain activity specifically linked to memory-related processing, contrary to more general perceptual processing, and can be used with healthy and clinical populations. https://www.jove.com/v/2433 957 2011-05-04T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53962.jpg Conscious and Non-conscious Representations of Emotional Faces in Asperger's Syndrome An EEG experimental protocol is designed to clarify the interplay between conscious and non-conscious representations of emotional faces in patients with Asperger's syndrome. The technique suggests that patients with Asperger's syndrome have deficits in non-conscious representation of emotional faces, but have comparable performance in conscious representation with healthy controls. https://www.jove.com/v/53962 511 2016-07-31T22:00:00+00:00 JoVE no https://visualize.jove.com/14563363-characterization-of-recombinant-and-native-ih-channels-from-apis-mellifera monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13393.jpg Immunocytochemistry and Immunohistochemistry Immunocytochemistry (ICC) and immunohistochemistry (IHC) are techniques that use antibodies to check for specific proteins or antigens in a sample. The technique was first published by Albert Coons in 1941 to detect the presence of pneumococcal antigen in tissue sections from mice infected with Pneumococcus. Immunocytochemistry helps localization of proteins or antigens in individual cells like blood cells, stem cells, etc., while immunohistochemistry does the same for tissue samples. These... https://www.jove.com/v/13393 82 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51629.jpg One-channel Cell-attached Patch-clamp Recording Described here is a procedure for obtaining long stretches of current recording from one ion channel with the cell-attached patch-clamp technique. This method allows for observing, in real time, the pattern of open-close channel conformations that underlie the biological signal. These data inform about channel properties in undisturbed biological membranes. https://www.jove.com/v/51629 787 2014-06-09T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54732.jpg Determination of the Relative Cell Surface and Total Expression of Recombinant Ion Channels Using Flow Cytometry Inherited cardiac arrhythmias are often caused by mutations that alter the surface delivery of one or more ion channels. Here, we adapt flow cytometry assays to provide a quantification of the relative total and cell surface protein expression of recombinant ion channels expressed in tsA-201 cells. https://www.jove.com/v/54732 692 2016-09-28T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55756.jpg Transient Expression and Cellular Localization of Recombinant Proteins in Cultured Insect Cells Nonlytic insect cell expression systems are underutilized for production, cellular trafficking/localization, and recombinant protein functional analysis. Here, we describe methods to generate expression vectors and subsequent transient protein expression in commercially available lepidopteran cell lines. The co-localization of Bemisia tabaci aquaporins with subcellular fluorescent marker proteins is also presented. https://www.jove.com/v/55756 729 2017-04-20T22:00:00+00:00 JoVE no https://visualize.jove.com/14628903-automated-biological-agent-testing-systems monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40768/40768_article_thumb_40768.jpg Bioreactor Design and Operational System Bioreactors are engineered vessels designed to cultivate microorganisms under controlled conditions for industrial bioprocessing. They maintain sterility and allow precise regulation of pH, temperature, oxygen, and nutrient levels to optimize microbial growth and metabolite production. Bioreactors range from small laboratory units of 1 liter to industrial systems holding up to 500,000 liters, though only about 75% of their volume is actively used for fermentation. The remaining headspace... https://www.jove.com/v/40768 89 2026-03-12T20:57:31+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40816/40816_article_thumb_40816.jpg Automated Microbial Diagnostics Automated diagnostic analyzers have transformed clinical microbiology by providing rapid and reliable methods for pathogen identification and antibiotic susceptibility testing. Among these systems, the Vitek 2 is widely used because it automates the traditionally labor-intensive processes of microbial identification (ID) and antibiotic susceptibility testing (AST), delivering standardized and timely results that are essential for effective patient care.Microbial Identification with ID CardsThe... https://www.jove.com/v/40816 84 2026-03-12T20:35:56+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51915.jpg A High Content Imaging Assay for Identification of Botulinum Neurotoxin Inhibitors Botulinum neurotoxin is one of the most potent toxins among Category-A biothreat agents, yet a post-exposure therapeutic is not available. The high content imaging approach is a powerful methodology for identifying novel inhibitors as it enables multiparameter screening using biologically relevant motor neurons, the primary target of this toxin. https://www.jove.com/v/51915 850 2014-11-14T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62838.jpg An Automated Culture System for Use in Preclinical Testing of Host-Directed Therapies for Tuberculosis Rapid and efficient quantification of intracellular M. tuberculosis growth is crucial for pursuing improved therapies against tuberculosis (TB). This protocol describes a broth-based colorimetric detection assay using an automated liquid culture system to quantify Mtb growth in macrophages treated with candidate host-directed therapies. https://www.jove.com/v/62838 574 2021-08-16T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66571.jpg Rapid Glyco-Qualitative Assessment of Recombinant Proteins Using a Fully Automated System A system for the automated and rapid analysis of glycans on proteins was previously developed. This article presents the protocol for "glyco-qualitative analysis," optimized for a broad spectrum of users, such as those engaged in analyzing glycan structures in biopharmaceuticals and other glycoconjugate materials. https://www.jove.com/v/66571 319 2024-06-28T20:00:00+00:00 JoVE no https://visualize.jove.com/14657176-neuronal-avalanches-in-neocortical-circuits monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2949.jpg Multi-electrode Array Recordings of Neuronal Avalanches in Organotypic Cultures A robust way to study neuronal avalanches, i.e. scale-invariant spatio-temporal activity bursts, indicative of critical state dynamics in cortex. Avalanches emerge spontaneously in developing superficial layers of cultured cortex which allows for long-term measurements of the activity with planar integrated multi-electrode arrays (MEA) under precisely controlled conditions. https://www.jove.com/v/2949 961 2011-08-01T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/12178/12178_article_thumb_Updated_12178.jpg Action Potential Neurons communicate by firing action potentials—the electrochemical signal that is propagated along the axon. The signal results in the release of neurotransmitters at axon terminals, thereby transmitting information to the nervous system. An action potential is a specific "all-or-none" change in membrane potential that results in a rapid spike in voltage. Membrane potential in neurons Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive... https://www.jove.com/v/12178 74 2025-08-28T22:01:35+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12181.jpg Electrical Synapses Electrical synapses found in all nervous systems play important and unique roles. In these synapses, the presynaptic and postsynaptic membranes are very close together (3.5 nm) and are actually physically connected by channel proteins forming gap junctions. Gap junctions allow the current to pass directly from one cell to the next. In contrast, in the chemical synapse, the neurotransmitters carry the information through the synaptic cleft from one neuron to the next. They consist of two... https://www.jove.com/v/12181 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12184.jpg The Role of Ion Channels in Neuronal Computation A postsynaptic neuron usually receives numerous impulses from several other presynaptic neurons. The axon hillock of the postsynaptic neuron integrates all these signals and determines the likelihood of firing an action potential. Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential. https://www.jove.com/v/12184 79 JoVE no https://cloudfront.jove.com/files/ftp_upload/14894/14894_article_thumb_14894.jpg Propagation of Action Potentials The propagation of an action potential refers to the process by which a nerve impulse, or "action potential," travels along a neuron. Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to... https://www.jove.com/v/14894 83 2025-08-11T22:39:58+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14900.jpg Neural Circuits Neural circuits and neuronal pools are two of the main structures found in the nervous system. Neural circuits are networks of neurons that work together to carry out a specific task or process. They consist of interconnected neurons and glial cells, which provide structural and metabolic support. Neuronal pools are collections of nerve cells with similar functions and interact through chemical and electrical signals. These pools include both interneurons (the central neural circuit nodes that... https://www.jove.com/v/14900 85 2025-06-13T16:07:11+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17743.jpg Neuronal Communication Neurons, the fundamental units of the brain and nervous system, communicate through complex electrochemical signals that underpin all cognitive and bodily functions. This communication is primarily facilitated by a process involving the generation and propagation of an action potential along the axon of the neuron. When the internal electrical charge of a neuron surpasses a certain threshold, an action potential is triggered. This rapid change in voltage travels swiftly along the axon to the... https://www.jove.com/v/17743 88 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52358.jpg Electrophysiological and Morphological Characterization of Neuronal Microcircuits in Acute Brain Slices Using Paired Patch-Clamp Recordings Patch-clamp recordings and simultaneous intracellular biocytin filling of synaptically coupled neurons in acute brain slices allow a correlated analysis of their structural and functional properties. The aim of this protocol is to describe the essential technical steps of electrophysiological recording from neuronal microcircuits and their subsequent morphological analysis. https://www.jove.com/v/52358 624 2015-01-10T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65899.jpg In Vivo Visualization of Spontaneous Activity in Neonatal Mouse Sensory Cortex at a Single-Neuron Resolution Primary sensory areas in the neocortex exhibit unique spontaneous activities during development. This article describes how to visualize individual neuron activities and primary sensory areas to analyze area-specific synchronous activities in neonatal mice in vivo. https://www.jove.com/v/65899 378 2023-11-21T22:00:00+00:00 JoVE no https://visualize.jove.com/14670693-the-automated-bioaerosol-exposure-system-preclinical-platform-development-and-a-respiratory-dosimetry-application-with-nonhuman-primates monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15004.jpg Preclinical Development: Overview Preclinical development consists of a series of tests that ensure the safety and efficacy of a new therapeutic compound before it is tested in humans. There are four main phases to this process. First, safety pharmacology tests are conducted to ensure the drug does not produce any acutely harmful effects. These tests examine parameters such as bronchoconstriction, cardiac dysrhythmias, blood pressure changes, and ataxia. Next, preliminary toxicological testing is performed to determine the... https://www.jove.com/v/15004 88 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50263.jpg Whole-Body Nanoparticle Aerosol Inhalation Exposures A whole-body nanoparticle aerosol inhalation exposure facility was constructed for nano-sized titanium dioxide (TiO2) inhalation toxicology studies. This system provides nano-TiO2 aerosol test atmospheres that have: 1) a steady mass concentration; 2) a homogenous composition free of contaminants; and 3) a stable particle size distribution during aerosol generation. https://www.jove.com/v/50263 611 2013-05-07T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53602.jpg Safety Precautions and Operating Procedures in an (A)BSL-4 Laboratory: 3. Aerobiology As high-consequence pathogens can potentially infect subjects through airborne particles, aerobiology has been increasingly applied in pathogenesis research and medical countermeasure development. We present a detailed visual demonstration of aerobiology procedures during an aerosol challenge in nonhuman primates in an animal biosafety level 4 maximum containment environment. https://www.jove.com/v/53602 673 2016-10-03T18:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61210.jpg An Air-liquid Interface Bronchial Epithelial Model for Realistic, Repeated Inhalation Exposure to Airborne Particles for Toxicity Testing Described is the cell culture and exposure method of an in vitro bronchial model for realistic, repeated inhalation exposure to particles for toxicity testing. https://www.jove.com/v/61210 569 2020-05-13T21:00:00+00:00 JoVE no https://visualize.jove.com/14683086-phase-synchronization-of-chaotic-attractors-with-prescribed-periodic-signals monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12764.jpg Oscillations about an Equilibrium Position Stability is an important concept in oscillation. If an equilibrium point is stable, a slight disturbance of an object that is initially at the stable equilibrium point will cause the object to oscillate around that point. For an unstable equilibrium point, if the object is disturbed slightly, it will not return to the equilibrium point. There are three conditions for equilibrium points—stable, unstable, and half-stable. A half-stable equilibrium point is also unstable, but is named so because... https://www.jove.com/v/12764 64 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12771.jpg Forced Oscillations When an oscillator is forced with a periodic driving force, the motion may seem chaotic. The motions of such oscillators are known as transients. After the transients die out, the oscillator reaches a steady state, where the motion is periodic, and the displacement is determined. Using the equations of force and motion, the amplitude of the driven oscillator is obtained. It depends on the natural and driving frequency. In the equation for amplitude, when the driving frequency is much smaller... https://www.jove.com/v/12771 66 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16030.jpg Classification of Signals In signal processing, signals are classified based on various characteristics: continuous-time versus discrete-time, periodic versus aperiodic, analog versus digital, and causal versus noncausal. Each category highlights distinct properties crucial for understanding and manipulating signals. A continuous-time signal holds a value at every instant in time, representing information seamlessly. In contrast, a discrete-time signal holds values only at specific moments, often denoted as x(n), where... https://www.jove.com/v/16030 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16057.jpg Properties of Laplace Transform-II Time differentiation, convolution, integration, and periodicity are fundamental concepts in analyzing functions and signals over time. Each concept provides a unique perspective on how functions evolve, interact, and repeat, offering essential tools for various scientific and engineering applications. Time differentiation involves analyzing the rate of change of a function over time. Mathematically, it is the derivative of a function with respect to time. This concept can be likened to tracking... https://www.jove.com/v/16057 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16103.jpg Linear Approximation in Time Domain Nonlinear systems often require sophisticated approaches for accurate modeling and analysis, with state-space representation being particularly effective. This method is especially useful for systems where variables and parameters vary with time or operating conditions, such as in a simple pendulum or a translational mechanical system with nonlinear springs. For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length, the... https://www.jove.com/v/16103 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16133.jpg Time and frequency -Domain Interpretation of Phase-lead Control Phase-lead controllers are commonly used in various control systems to enhance response speed and stability. Adjusting the brightness on a television screen offers a practical example of phase-lead control. When contrast is enhanced, a phase-lead controller is employed. Mathematically, phase-lead control is identified when the first parameter is smaller than the second. The design of phase-lead control involves the strategic placement of poles and zeros to balance steady-state error and system... https://www.jove.com/v/16133 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57349.jpg Optogenetic Entrainment of Hippocampal Theta Oscillations in Behaving Mice We describe the use of optogenetics and electrophysiological recordings for selective manipulations of hippocampal theta oscillations (5-10 Hz) in behaving mice. The efficacy of the rhythm entrainment is monitored using local field potential. A combination of opto- and pharmacogenetic inhibition addresses the efferent readout of hippocampal synchronization. https://www.jove.com/v/57349 453 2018-06-29T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57517.jpg Generation and Coherent Control of Pulsed Quantum Frequency Combs A protocol is presented for the practical generation and coherent manipulation of high-dimensional frequency-bin entangled photon states using integrated micro-cavities and standard telecommunications components, respectively. https://www.jove.com/v/57517 402 2018-06-08T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68955.jpg Age-dependent Dynamics of Locomotion in Caenorhabditis elegans : A Lyapunov Exponent Analysis This study examines the effect of age on locomotion in C. elegans by measuring the largest Lyapunov exponent (LLE). As they age, C. elegans show an increase and subsequent decline in motor control. Results show a peak LLE at five days, followed by a decline as the worms age. https://www.jove.com/v/68955 404 2025-09-23T21:45:00+00:00 JoVE no https://visualize.jove.com/14688408-an-approach-to-genomewide-screens-of-expressed-small-interfering-rnas-in-mammalian-cells monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2008.jpg MISSION esiRNA for RNAi Screening in Mammalian Cells Here we use a human esiRNA library in a high-throughput screen for genes involved in cell division. We demonstrate how to set up and conduct an esiRNA screens, as well as how to analyze and validate the results. https://www.jove.com/v/2008 931 2010-05-13T00:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/3448.jpg Quantitative and Automated High-throughput Genome-wide RNAi Screens in C. elegans We describe a protocol using C. elegans and RNAi feeding libraries that allows automated measurement of multiple parameters such as fluorescence, size and opacity of individual worms in a population. We give one example of a screen to identify genes involved in anti-fungal innate immunity in C. elegans. https://www.jove.com/v/3448 658 2012-02-27T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10804.jpg RNA Interference RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated. This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used... https://www.jove.com/v/10804 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12025.jpg Genetic Screens Genetic screens are tools used to identify genes and mutations responsible for phenotypes of interest. Genetic screens help identify individuals or a group of people at risk of developing genetic diseases and help them with early intervention, targeted therapy, and reproductive options. Forward genetic screens Forward or “classical” genetic screens involve creating random mutations in an organism’s DNA using radiation, mutagens, or insertion of additional bases, which result in visible changes... https://www.jove.com/v/12025 166 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12033.jpg Experimental RNAi RNA interference (RNAi) is a cellular mechanism that inhibits gene expression by suppressing its transcription or activating the RNA degradation process. The mechanism was discovered by Andrew Fire and Craig Mello in 1998 in plants. Today, it is observed in almost all eukaryotes, including protozoa, flies, nematodes, insects, parasites, and mammals. This precise cellular mechanism of gene silencing has been developed into a technique that provides an efficient way to identify and determine the... https://www.jove.com/v/12033 135 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59780.jpg Pooled CRISPR-Based Genetic Screens in Mammalian Cells CRISPR-Cas9 technology provides an efficient method to precisely edit the mammalian genome in any cell type and represents a novel means to perform genome-wide genetic screens. A detailed protocol discussing the steps required for the successful performance of pooled genome-wide CRISPR-Cas9 screens is provided here. https://www.jove.com/v/59780 545 2019-09-04T20:00:00+00:00 JoVE no https://visualize.jove.com/14704668-restriction-enzyme-generated-sirna-regs-vectors-and-libraries monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/59233.jpg Overexpressing Long Noncoding RNAs Using Gene-activating CRISPR Traditional cDNA-based overexpression techniques have a limited applicability for the overexpression of long noncoding RNAs due to their multiple splice forms with potential functionality. This review reports a protocol using CRISPR technology to overexpress multiple splice variants of a long noncoding RNA. https://www.jove.com/v/59233 784 2019-03-01T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59241.jpg Lentiviral Vector Platform for the Efficient Delivery of Epigenome-editing Tools into Human Induced Pluripotent Stem Cell-derived Disease Models Targeted DNA epigenome editing represents a powerful therapeutic approach. This protocol describes the production, purification, and concentration of all-in-one lentiviral vectors harboring the CRISPR-dCas9-DNMT3A transgene for epigenome-editing applications in human induced pluripotent stem cell (hiPSC)-derived neurons. https://www.jove.com/v/59241 827 2019-03-29T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64389.jpg Isolation of Next-Generation Gene Therapy Vectors through Engineering, Barcoding, and Screening of Adeno-Associated Virus (AAV) Capsid Variants AAV peptide display library generation and subsequent validation through the barcoding of candidates with novel properties for the creation of next-generation AAVs. https://www.jove.com/v/64389 560 2022-10-18T21:00:00+00:00 JoVE no https://visualize.jove.com/14712067-auto-acetylation-of-transcription-factors-as-a-control-mechanism-in-gene-expression monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11537.jpg Histone Modification The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression. Acetylation The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,... https://www.jove.com/v/11537 152 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11584.jpg RNA Polymerase II Accessory Proteins Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in... https://www.jove.com/v/11584 156 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11612.jpg Co-activators and Co-repressors Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into... https://www.jove.com/v/11612 124 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11613.jpg Eukaryotic Transcription Activators Transcription activators are proteins that promote the transcription of genes from DNA to RNA. In most cases, these proteins contain two separate domains ‒ a domain that binds to DNA and a domain for activating transcription; however, in some cases, a single domain is responsible for both binding and activation of transcription, as seen in the glucocorticoid receptor and MyoD. The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These domains are... https://www.jove.com/v/11613 162 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11615.jpg Combinatorial Gene Control Combinatorial gene control is the synergistic action of several transcriptional factors to regulate the expression of a single gene. The absence of one or more of these factors may lead to a significant difference in the level of gene expression or repression. The expression of more than 30,000 genes is controlled by approximately 2000-3000 transcription factors. This is possible because a single transcription factor can recognize more than one regulatory sequence. The specificity in gene... https://www.jove.com/v/11615 153 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11612.jpg Co-activators and Co-repressors Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into... https://www.jove.com/v/13147 124 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57061.jpg A Facile Protocol to Generate Site-Specifically Acetylated Proteins in Escherichia Coli Genetic code expansion serves as a powerful tool to study a wide range of biological processes, including protein acetylation. Here we demonstrate a facile protocol to exploit this technique for generating homogeneously acetylated proteins at specific sites in Escherichia coli cells. https://www.jove.com/v/57061 668 2017-12-09T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58222.jpg Repressing Gene Transcription by Redirecting Cellular Machinery with Chemical Epigenetic Modifiers Regulation of the chromatin environment is an essential process required for proper gene expression. Here, we describe a method for controlling gene expression through the recruitment of chromatin-modifying machinery in a gene-specific and reversible manner. https://www.jove.com/v/58222 628 2018-09-20T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59375.jpg Chromatin Immunoprecipitation Assay Using Micrococcal Nucleases in Mammalian Cells Chromatin immunoprecipitation (ChIP) is a powerful tool for understanding the molecular mechanisms of gene regulation. However, the method involves difficulties in obtaining reproducible chromatin fragmentation by mechanical shearing. Here, we provide an improved protocol for a ChIP assay using enzymatic digestion. https://www.jove.com/v/59375 702 2019-05-10T21:30:00+00:00 JoVE no https://visualize.jove.com/14750978-stimulus-induced-change-in-long-range-temporal-correlations-and-scaling-behaviour-of-sensorimotor-oscillations monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/52420.jpg Infant Auditory Processing and Event-related Brain Oscillations High-density electroencephalography (dEEG) is being used increasingly to study brain development and plasticity in the early years of life. Here we present an application of sophisticated analysis techniques that builds on traditional EEG recording to understand the oscillatory dynamics of rapid auditory processing in the infant brain. https://www.jove.com/v/52420 394 2015-07-01T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57349.jpg Optogenetic Entrainment of Hippocampal Theta Oscillations in Behaving Mice We describe the use of optogenetics and electrophysiological recordings for selective manipulations of hippocampal theta oscillations (5-10 Hz) in behaving mice. The efficacy of the rhythm entrainment is monitored using local field potential. A combination of opto- and pharmacogenetic inhibition addresses the efferent readout of hippocampal synchronization. https://www.jove.com/v/57349 453 2018-06-29T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59898.jpg A Method for Tracking the Time Evolution of Steady-State Evoked Potentials A protocol to assess the time evolution of the neural entrainment to external repetitive stimuli is presented. Steady-state recordings of the same experimental condition are acquired and averaged in the time-domain. The steady-state dynamics are analyzed by plotting the response amplitude as a function of time. https://www.jove.com/v/59898 723 2019-05-25T22:00:00+00:00 JoVE no https://visualize.jove.com/14754240-nonlinear-analysis-of-correlations-in-alu-repeat-sequences-in-dna monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2279.jpg An Allele-specific Gene Expression Assay to Test the Functional Basis of Genetic Associations Genetic associations often remain unexplained at a functional level. This method aims to assess the effect of phenotype-associated genetic markers on gene expression by analyzing cells heterozygous for transcribed SNPs. The technology allows accurate measurement by MALDI-TOF mass spectrometry to quantify allele-specific primer extension products. https://www.jove.com/v/2279 617 2010-11-03T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/4401.jpg Analyzing and Building Nucleic Acid Structures with 3DNA The 3DNA software package is a popular and versatile bioinformatics tool with capabilities to analyze, construct, and visualize three-dimensional nucleic acid structures. This article presents detailed protocols for a subset of new and popular features available in 3DNA, applicable to both individual structures and ensembles of related structures. https://www.jove.com/v/4401 984 2013-04-26T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11474.jpg DNA Base Pairing Erwin Chargaff’s rules on DNA equivalence paved the way for the discovery of base pairing in DNA. Chargaff’s rules state that in a double-stranded DNA molecule, the amount of adenine (A) is equal to the amount of thymine (T); the amount of guanine (G) is equal to the amount of cytosine (C); and the sum of purines, A and G, is equal to the sum of pyrimidines, C and T (i.e., A+G = C+T). Later work by Watson and Crick revealed that in double-stranded DNA, A always forms two hydrogen bonds... https://www.jove.com/v/11474 147 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11474.jpg DNA Base Pairing Erwin Chargaff’s rules on DNA equivalence paved the way for the discovery of base pairing in DNA. Chargaff’s rules state that in a double-stranded DNA molecule, the amount of adenine (A) is equal to the amount of thymine (T); the amount of guanine (G) is equal to the amount of cytosine (C); and the sum of purines, A and G, is equal to the sum of pyrimidines, C and T (i.e., A+G = C+T). Later work by Watson and Crick revealed that in double-stranded DNA, A always forms two hydrogen bonds... https://www.jove.com/v/11547 147 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11987.jpg Evolutionary Relationships through Genome Comparisons Genome comparison is one of the excellent ways to interpret the evolutionary relationships between organisms. The basic principle of genome comparison is that if two species share a common feature, it is likely encoded by the DNA sequence conserved between both species. The advent of genome sequencing technologies in the late 20th century enabled scientists to understand the concept of conservation of domains between species and helped them to deduce evolutionary relationships across diverse... https://www.jove.com/v/11987 174 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12020.jpg Sanger Sequencing DNA sequencing is a fundamental technique that is routinely used in the biological sciences. This method can be applied to a range of questions at different scales - from the sequencing of a cloned DNA fragment or the study of a mutation in a gene up to whole-genome sequencing. However, despite the widespread use of sequencing today, it was not until 1977 that Fredrick Sanger and his collaborators developed the chain-termination method to decode DNA sequences. It relies on the separation of a... https://www.jove.com/v/12020 117 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14371.jpg Nucleic Acid Structure The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group on the ribose's second carbon and a hydrogen on the deoxyribose's second carbon. The phosphate residue attaches to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms a 5′ to 3′ phosphodiester linkage. DNA Structure DNA has a double-helix structure. The... https://www.jove.com/v/14371 85 JoVE no https://cloudfront.jove.com/files/ftp_upload/19557/19557_article_thumb_19557.jpg Modern Molecular Taxonomy Advancements in molecular biology have revolutionized the identification and characterization of bacteria, with multiple methods leveraging DNA sequencing for enhanced precision. As sequencing technologies improve and costs decline, these approaches are increasingly used in clinical, environmental, and evolutionary studies.Multilocus Sequence Typing (MLST) examines several housekeeping genes, essential chromosomal genes encoding cellular functions, to distinguish strains. Approximately... https://www.jove.com/v/19557 89 2025-06-12T16:19:23+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59760.jpg Use of Alu Element Containing Minigenes to Analyze Circular RNAs We clone and analyze reporter genes generating circular RNAs. These reporter genes are larger than constructs to analyze linear splicing and contain Alu elements. To investigate the circular RNAs, the constructs are transfected into cells and resulting RNA is analyzed using RT-PCR after removal of linear RNA. https://www.jove.com/v/59760 790 2020-03-10T19:00:00+00:00 JoVE no https://visualize.jove.com/14757008-basis-types-and-application-of-dna-arrays-in-clinical-microbiology monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2682.jpg ampliPHOX Colorimetric Detection on a DNA Microarray for Influenza ampliPHOX colorimetric detection technology is presented as an inexpensive alternative to fluorescence detection for microarrays. Based on photopolymerization, ampliPHOX produces solid polymer spots visible to the naked eye in just a few minutes. Results are then imaged and automatically interpreted with a simple yet powerful software package. https://www.jove.com/v/2682 572 2011-06-09T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12014.jpg DNA Microarrays Microarrays are high-throughput and relatively inexpensive assays that can be automated to analyze large quantities of data at a time. They are used in genome-wide studies to compare gene or protein expression under two varied conditions, such as healthy and diseased states. Microarrays consist of glass or silica slides on which probe molecules are covalently attached through surface functionalization. Most commonly, the slides are prepared through the chemisorption of silanes to silica... https://www.jove.com/v/12014 154 JoVE no https://cloudfront.jove.com/files/ftp_upload/19556/19556_article_thumb_19556.jpg Methods of Classification and Identification Bacterial identification relies on a diverse array of techniques to classify and understand microorganisms, each tailored to uncover specific characteristics. Traditional morphological approaches, while still valuable, are limited for closely related or structurally simple organisms. Modern methods integrate biochemical, serological, genetic, and advanced molecular tools to achieve greater accuracy.Morphological and Biochemical TechniquesMorphological characteristics, such as cell shape and... https://www.jove.com/v/19556 88 2025-06-12T16:19:11+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19557/19557_article_thumb_19557.jpg Modern Molecular Taxonomy Advancements in molecular biology have revolutionized the identification and characterization of bacteria, with multiple methods leveraging DNA sequencing for enhanced precision. As sequencing technologies improve and costs decline, these approaches are increasingly used in clinical, environmental, and evolutionary studies.Multilocus Sequence Typing (MLST) examines several housekeeping genes, essential chromosomal genes encoding cellular functions, to distinguish strains. Approximately... https://www.jove.com/v/19557 89 2025-06-12T16:19:23+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19558/19558_article_thumb_19558.jpg Applications of Molecular Taxonomy Molecular taxonomy has revolutionized the understanding and classification of bacteria, providing precise insights into their diversity, evolutionary relationships, and ecological roles. By utilizing molecular techniques such as DNA sequencing and fingerprinting, researchers have made significant strides in various fields related to bacterial studies.Resolving Taxonomic AmbiguitiesMolecular taxonomy has been instrumental in distinguishing closely related bacterial species initially thought to... https://www.jove.com/v/19558 80 2025-06-12T16:19:34+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40815/40815_article_thumb_40815.jpg Rapid Identification of Pathogens MALDI-TOF MS has transformed clinical microbiology by offering a rapid and reliable method for pathogen identification. The traditional approach to microbial identification typically involves time-consuming culture techniques and biochemical tests, which can delay the initiation of appropriate antimicrobial therapy. MALDI-TOF MS avoids these delays by using characteristic ribosomal protein mass patterns of microbial cells, enabling accurate species-level identification within minutes.Principle... https://www.jove.com/v/40815 85 2026-05-20T20:51:01+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40816/40816_article_thumb_40816.jpg Automated Microbial Diagnostics Automated diagnostic analyzers have transformed clinical microbiology by providing rapid and reliable methods for pathogen identification and antibiotic susceptibility testing. Among these systems, the Vitek 2 is widely used because it automates the traditionally labor-intensive processes of microbial identification (ID) and antibiotic susceptibility testing (AST), delivering standardized and timely results that are essential for effective patient care.Microbial Identification with ID CardsThe... https://www.jove.com/v/40816 84 2026-03-12T20:35:56+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51256.jpg Demonstrating a Multi-drug Resistant Mycobacterium tuberculosis Amplification Microarray An amplification microarray combines asymmetric PCR amplification and microarray hybridization into a single chamber, which significantly streamlines microarray workflow for the end user. Simplifying microarray workflow is a necessary first step for creating microarray-based diagnostics that can be routinely used in lower-resource environments. https://www.jove.com/v/51256 455 2014-04-25T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68234.jpg Identification of Mycobacterium Species by DNA Microarray Chip Method Here, we present a DNA microarray chip method for identifying Mycobacterium species, which will improve diagnostic accuracy and efficiency of related diseases for clinical use. https://www.jove.com/v/68234 387 2025-06-24T21:30:00+00:00 JoVE no https://visualize.jove.com/14971741-demonstration-of-a-chaos-generator-with-two-time-delays monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13733.jpg Van de Graaff Generator Van de Graaff generators (or Van de Graaffs) are devices used to demonstrate high voltage due to static electricity that can also be used for research. Robert Van de Graaff first built one in 1931 (based on original suggestions by Lord Kelvin) for use in nuclear physics research. Van de Graaff uses both smooth and pointed surfaces, conductors, and insulators to generate large static charges and, hence, large voltages. A substantial excess charge can be deposited on the sphere because it moves... https://www.jove.com/v/13733 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13804.jpg Current Growth And Decay In RL Circuits The current growth and decay in RL circuits can be understood by considering a series RL circuit consisting of a resistor, an inductor, a constant source of emf, and two switches. When the first switch is closed, the circuit is equivalent to a single-loop circuit consisting of a resistor and an inductor connected to a source of emf. In this case, the source of emf produces a current in the circuit. If there were no self-inductance in the circuit, the current would rise immediately to a steady... https://www.jove.com/v/13804 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15127.jpg Generation of Three-Phase Voltage A three-phase AC generator has a rotor with a rotating magnet placed within the stator mounted with the stationary three-phase winding to generate three-phase voltages via mutual induction. These windings are evenly distributed around the inner circumference of the stator and are arranged 120 electrical degrees apart. Three-phase stator windings consist of three separate coils or groups of coils, known as phases, each connected in Y (star) configuration or Delta configuration. As the rotor... https://www.jove.com/v/15127 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15723.jpg Clamper Circuit A clamper circuit, also known as a DC restorer, represents a specialized variant of the rectifier circuit, notable for its method of taking the output across the diode rather than the capacitor. This configuration lends to several distinctive applications, particularly in handling square wave inputs. Within this circuit, the diode's orientation prompts the capacitor to charge up to the level of the most negative peak of the input signal. Upon reaching this state, the diode ceases to conduct,... https://www.jove.com/v/15723 74 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16072.jpg Properties of DTFT I In signal processing, Discrete-Time Fourier Transforms (DTFTs) play a critical role in analyzing discrete-time signals in the frequency domain. Various properties of the DTFTs such as linearity, time-shifting, frequency-shifting, time reversal, conjugation, and time scaling help understand and manipulate these signals for different applications. The linearity property of DTFTs is fundamental. If two discrete-time signals are multiplied by constants a and b respectively, and then combined to... https://www.jove.com/v/16072 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16172.jpg Generator Voltage Control Generator voltage control is crucial for maintaining the stable operation of synchronous generators and wind turbines. In older models, a DC generator driven by the rotor delivers DC power to the rotor's field winding, and the power is transferred through slip rings and brushes. In the latest models, static or brushless exciters are used. Static exciters rectify AC power from the generator terminals and then transfer the DC power directly to the rotor. Brushless exciters, on the other hand, use... https://www.jove.com/v/16172 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57517.jpg Generation and Coherent Control of Pulsed Quantum Frequency Combs A protocol is presented for the practical generation and coherent manipulation of high-dimensional frequency-bin entangled photon states using integrated micro-cavities and standard telecommunications components, respectively. https://www.jove.com/v/57517 402 2018-06-08T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59812.jpg Using Neuron Spiking Activity to Trigger Closed-Loop Stimuli in Neurophysiological Experiments This protocol demonstrates how to use an electrophysiological system for closed-loop stimulation triggered by neuronal activity patterns. Sample Matlab code that can be easily modified for different stimulation devices is also provided. https://www.jove.com/v/59812 319 2019-11-12T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67464.jpg Experimental Investigation of the Hierarchical Control in DC Microgrids Using a Real-time Simulator This article presents a DC microgrid with hierarchical control implemented in a simulator, OPAL RT-Lab. It details the circuit modeling, primary and secondary control strategies, and experimental validation. The results demonstrate effective control performance, highlighting the importance of a robust experimental platform for microgrid research and development. https://www.jove.com/v/67464 364 2025-02-14T22:20:00+00:00 JoVE no https://visualize.jove.com/14980301-apparent-life-threatening-events-and-sudden-infant-death-on-a-monitor monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3368.jpg Assessment and Evaluation of the High Risk Neonate: The NICU Network Neurobehavioral Scale The NICU Network Neurobehavioral Scale (NNNS) was developed as an assessment for the at-risk infant. The purpose of this article is to describe the NNNS, provide video examples of the NNNS procedures and discuss the ways in which the exam has been used. https://www.jove.com/v/3368 1155 2014-08-25T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13263.jpg Guidelines For Measuring Vital Signs Following these guidelines can help nurses accurately measure vital signs, assess changes in patient conditions, and provide timely treatment when necessary. Adhering closely to the guidelines ensures the accuracy and reliability of the results. Before taking a patient's vital signs, a nurse would consider and assess the patient's comfort level and ensure appropriate equipment is available. • Patient Comfort Level: Patients must be relaxed and comfortable before vital sign measurement. https://www.jove.com/v/13263 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13286.jpg Pulse rhythm Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding. Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle... https://www.jove.com/v/13286 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13299.jpg Assessment of Ventilation I: Respiratory Rate Assessment of Ventilation A Ventilation assessment is critical for monitoring a patient's health status. Respiration, one of the most accessible vital signs, provides insights into the function of numerous body systems and can indicate serious health issues, such as brainstem injuries from head trauma. Critical Guidelines for Assessing Ventilation: Unobtrusive Observation: Maintaining accuracy in ventilation assessment is paramount. Observing the patient's breathing without their knowledge is... https://www.jove.com/v/13299 80 JoVE no https://cloudfront.jove.com/files/ftp_upload/17887/17887_article_thumb_17887.jpg Holter Monitor: 24-Hour Monitoring Holter monitoring is a continuous electrocardiography (ECG) recording that tracks the heart's electrical activity over an extended period, generally 24 to 48 hours. This noninvasive diagnostic tool detects irregular heart rhythms that may not be captured during a standard ECG performed in a clinical setting.DeviceThe Holter monitor is a portable, small device connected to several electrodes on the patient's chest. These electrodes detect the heart's electrical signals and transmit them to the... https://www.jove.com/v/17887 83 2025-06-19T16:09:27+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55985.jpg Application of an Amplitude-integrated EEG Monitor (Cerebral Function Monitor) to Neonates Here, we show how to apply amplitude-integrated electroencephalography to monitor cerebral function in neonates. https://www.jove.com/v/55985 358 2017-09-06T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64931.jpg A Modified Sonographic Algorithm for Image Acquisition in Life-Threatening Emergencies in the Critically Ill Newborn Here, we present a protocol that can be applied in the neonatal intensive care unit and the delivery room in relation to three scenarios: cardiac arrest, hemodynamic deterioration, or respiratory decompensation. This protocol can be performed with a state-of-the-art ultrasound machine or an affordable handheld device; an image acquisition protocol is carefully detailed. https://www.jove.com/v/64931 687 2023-04-07T20:00:00+00:00 JoVE no https://visualize.jove.com/14988500-overexpression-of-acid-sensing-ion-channel-1a-in-transgenic-mice-increases-acquired-fear-related-behavior monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1088.jpg Elevated Plus Maze for Mice The elevated plus maze test is one of the most widely used tests for measuring anxiety-like behavior in mice. Here, we present a movie showing the detailed procedures for conducting the test. https://www.jove.com/v/1088 549 2008-12-22T08:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50871.jpg Contextual and Cued Fear Conditioning Test Using a Video Analyzing System in Mice This article presents a protocol for a contextual and cued fear conditioning test using a video analyzing system to assess fear learning and memory in mice. https://www.jove.com/v/50871 1172 2014-03-01T23:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67130.jpg Observational Fear as a Model of Affective Empathy in Mice The observational fear paradigm assesses vicarious freezing in rodents as a model for affective empathy. This procedure entails exposing observer rodents to conspecific demonstrators receiving aversive foot shocks to elicit empathic freezing responses. By employing observational fear assays, researchers can investigate the neural mechanisms underlying affective empathy. https://www.jove.com/v/67130 254 2024-11-22T22:00:00+00:00 JoVE no https://visualize.jove.com/14993478-artificial-neural-networks-improve-the-prediction-of-ktv-follow-up-dietary-protein-intake-and-hypotension-risk-in-haemodialysis-patients monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/18482/18482_article_thumb_18482.jpg Hemodialysis III: Nursing Management The nursing management of a patient undergoing hemodialysis includes several critical steps, starting with a thorough assessment before the procedure.Before the Hemodialysis ProcedureFirst, record the patient's vital signs—blood pressure, heart rate, respiratory rate, and temperature—to establish a baseline. This baseline is essential for detecting conditions such as hypotension that could impact the patient's response to dialysis. Document the patient's pre-dialysis weight, as this measurement... https://www.jove.com/v/18482 85 2025-06-19T16:28:13+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18500/18500_article_thumb_18500.jpg Acute Kidney Injury IV: Diagnostic Studies and Prevention Accurate diagnosis and effective prevention are critical in managing Acute Kidney Injury (AKI), which is linked to high mortality rates ranging from 10% to 80%. Timely recognition of at-risk patients and careful monitoring can significantly reduce the likelihood of kidney damage.Diagnostic Assessments:The diagnostic process starts with a comprehensive medical history to identify prerenal, intrarenal, and postrenal causes.Prerenal causes, such as dehydration, hypotension, or blood loss, should... https://www.jove.com/v/18500 90 2025-06-19T16:31:44+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18501/18501_article_thumb_18501.jpg Acute Kidney Injury V: Interprofessional Care Acute Kidney Injury (AKI) requires a collaborative healthcare approach to restore renal function and prevent complications. Essential management strategies involve monitoring fluid and electrolyte balance, adjusting medications, initiating dialysis when necessary, and providing nutritional support.Fluid and Electrolyte ManagementFluid Monitoring: Regularly monitoring body weight, central venous pressure, and urine output helps detect fluid imbalances early. Patient intake and output are... https://www.jove.com/v/18501 80 2025-06-19T16:32:01+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18502/18502_article_thumb_18502.jpg Acute Kidney Injury VI: Nursing Management Acute Kidney Injury (AKI) results in an inability to maintain fluid, electrolyte, and acid-base balance. Effective nursing management is critical in improving patient outcomes and includes comprehensive patient assessment and targeted interventions.Comprehensive Patient AssessmentA detailed history collection is essential, focusing on any recent infections, nephrotoxic medication use, or chronic conditions such as hypertension and diabetes that may contribute to AKI. During the physical... https://www.jove.com/v/18502 82 2025-06-19T16:32:16+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18505/18505_article_thumb_18505.jpg Chronic Kidney Disease III: Interprofessional Care Chronic kidney disease (CKD) requires collaborative and comprehensive management. CKD progresses through stages and can lead to end-stage kidney disease (ESKD) if untreated. Interprofessional collaboration and patient education are crucial, enabling patients to manage their health and improve their quality of life.Diagnostic approach for chronic kidney diseaseThe diagnosis of CKD primarily focuses on the glomerular filtration rate (GFR), which assesses kidney function by measuring how well... https://www.jove.com/v/18505 88 2025-06-19T16:32:48+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18507/18507_article_thumb_18507.jpg Chronic Kidney Disease IV: Nursing Management Nursing management is essential for preventing complications, maintaining stability, and improving patients' quality of life in chronic kidney disease (CKD). By using a structured approach, nurses help slow CKD progression and support effective patient care​.1. Comprehensive patient assessmentEffective management begins with nurses reviewing the patient’s medical history, and identifying key risk factors like diabetes, hypertension, and nephrotoxic drug use. Nurses assess signs of fluid... https://www.jove.com/v/18507 78 2025-06-19T16:33:10+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62230.jpg A Large Animal Model for Acute Kidney Injury by Temporary Bilateral Renal Artery Occlusion This study presents a highly reproducible large animal model of renal ischemia-reperfusion injury in swine using temporary percutaneous bilateral balloon-catheter occlusion of the renal arteries for 60 min and reperfusion for 24 h. https://www.jove.com/v/62230 542 2021-02-02T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63892.jpg A Murine Model of Hemodialysis Access-Related Hand Dysfunction This protocol details the surgical steps of murine common iliac arteriovenous fistula creation. We developed this model to study hemodialysis access-related limb pathophysiology. https://www.jove.com/v/63892 519 2022-05-31T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67322.jpg 5/6 Nephrectomy Using Sharp Bipolectomy Via Midline Laparotomy in Rats This manuscript introduces a standardized protocol for a 5/6 nephrectomy by sharp bipolectomy via midline laparotomy in a rat model, aiming to induce a state of renal insufficiency via renal parenchyma reduction with a great degree of methodical precision and low risk of technical error. https://www.jove.com/v/67322 334 2025-04-04T20:00:00+00:00 JoVE no https://visualize.jove.com/15010830-alphavirus-vectors-for-cancer-gene-therapy-review monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2538.jpg High-Efficiency Transduction of Liver Cancer Cells by Recombinant Adeno-Associated Virus Serotype 3 Vectors In this article, we describe the identification of the adeno-associated virus serotype 3 (AAV3) as the most efficient vector for targeting human liver cancer cells. <br... https://www.jove.com/v/2538 1142 2011-03-22T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10815.jpg Gene Therapy Gene therapy is a technique where a gene is inserted into a person’s cells to prevent or treat a serious disease. The added gene may be a healthy version of the gene that is mutated in the patient, or it could be a different gene that inactivates or compensates for the patient’s disease-causing gene. For example, in patients with severe combined immunodeficiency (SCID) due to a mutation in the gene for the enzyme adenosine deaminase, a functioning version of the gene can be inserted. The... https://www.jove.com/v/10815 59 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10815.jpg Gene Therapy Gene therapy is a technique where a gene is inserted into a person’s cells to prevent or treat a serious disease. The added gene may be a healthy version of the gene that is mutated in the patient, or it could be a different gene that inactivates or compensates for the patient’s disease-causing gene. For example, in patients with severe combined immunodeficiency (SCID) due to a mutation in the gene for the enzyme adenosine deaminase, a functioning version of the gene can be inserted. The... https://www.jove.com/v/12040 59 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12083.jpg Mechanisms of Retrovirus-induced Cancers Retroviruses are RNA viruses that have been shown to cause cancers in diverse species, including chickens, mice, cats, and monkeys. The RNA genomes of these viruses are first reverse-transcribed into single and then double-stranded DNA (dsDNA) copies. This dsDNA called proviral DNA then integrates into the host genome. Subsequently, the host cell transcribes the proviral DNA in concert with the chromosomal DNA. This leads to the production of viral RNA and proteins that assemble at the host... https://www.jove.com/v/12083 111 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12233.jpg Rous Sarcoma Virus (RSV) and Cancer Rous Sarcoma virus or RSV was discovered by F. Peyton Rous in the year 1911 as a filterable transmissible agent that could cause tumors in chickens. He won a Nobel Prize for this discovery in 1966. His experiments clearly demonstrated that some cancers could be caused by infectious agents and led to the discovery of many more cancer-causing viruses in animals as well as humans. RSV is a retrovirus that contains two copies of a plus-strand RNA genome. Its genome consists of four main open... https://www.jove.com/v/12233 63 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16322.jpg Cancer Vaccines Cancer treatment vaccines are a rapidly evolving field that offers a promising approach to immunotherapy. Unlike traditional vaccines that prevent diseases, cancer treatment vaccines are designed to treat existing cancers by stimulating the immune system to recognize and attack cancer cells. Cancer vaccines come in two categories: preventive (prophylactic) and treatment (active). Preventive vaccines, such as the Human Papillomavirus (HPV) vaccine, protect against viruses that cause certain... https://www.jove.com/v/16322 90 JoVE no https://cloudfront.jove.com/files/ftp_upload/19466/19466_article_thumb_19466.jpg Microorganisms in Medicine and Therapeutics Microorganisms play a fundamental role in vaccine development, gene therapy, and therapeutic production. Their biological properties are harnessed to advance medicine and public health. Beyond immunization, microorganisms contribute to gut health, antibiotic synthesis, and genetic disease treatment.Live Attenuated and Inactivated VaccinesLive attenuated vaccines, such as the measles, mumps, and rubella (MMR) vaccine, utilize weakened forms of pathogens to closely resemble natural infections. https://www.jove.com/v/19466 89 2026-02-11T18:41:05+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62727.jpg Production of Adeno-Associated Virus Vectors in Cell Stacks for Preclinical Studies in Large Animal Models Here we provide a detailed procedure for large-scale production of research-grade AAV vectors using adherent HEK 293 cells grown in cell stacks and affinity chromatography purification. This protocol consistently yields >1 x 1013 vector genomes/mL, providing vector quantities appropriate for large animal studies. https://www.jove.com/v/62727 441 2021-06-30T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67252.jpg Quantification of Adeno-Associated Viral Genomes in Purified Vector Samples by Digital Droplet Polymerase Chain Reaction Precise quantification of adeno-associated virus (AAV) vector genome copies is critical, but a standardized protocol has yet to be established. This protocol describes a validated method for preparing purified AAV samples and conducting digital droplet polymerase chain reaction (dd_PCR) to reliably quantify the viral genome titer. https://www.jove.com/v/67252 283 2024-10-11T21:40:00+00:00 JoVE no https://visualize.jove.com/15026839-assessment-of-cardiovascular-autonomic-control-by-the-empirical-mode-decomposition monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15275.jpg Correlation between ECG and Cardiac Cycle The electrical signals recorded on an electrocardiogram (ECG) occur before the mechanical processes of contraction and relaxation during the cardiac cycle. A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before... https://www.jove.com/v/15275 85 2025-05-15T16:16:28+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17868.jpg Assessment of the Cardiovascular System I: Subjective Data A thorough health history and physical assessment are essential for identifying cardiovascular disease (CVD) symptoms and distinguishing them from other health issues. Initial Enquiry Ask the patient about their primary concern and thoroughly explore all reported symptoms. Medical History Investigate past illnesses affecting the cardiovascular system, such as angina, anemia, rheumatic fever, congenital heart disease, stroke, thrombophlebitis, dysrhythmias, varicosities Inquire about symptoms... https://www.jove.com/v/17868 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17871.jpg Assessment of the Cardiovascular System IV: Auscultation Cardiac auscultation is a clinical skill used to assess heart function and detect abnormalities. It involves listening to heart sounds at specific anatomical locations through a stethoscope. Normal Heart Sounds S1 (First Heart Sound)- S1 is made by the closure of the mitral and tricuspid valves (atrioventricular valves), marking the beginning of systole. S2 (Second Heart Sound)- S2 is made by the closure of the aortic and pulmonic valves (semilunar valves), marking the end of the systole.<br... https://www.jove.com/v/17871 85 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50073.jpg Measuring Cardiac Autonomic Nervous System (ANS) Activity in Children Measurement of autonomic nervous system activity usually confines the researcher and participant to the laboratory, which may provide an intimidating environment to children. The VU University Ambulatory Monitoring System (VU-AMS) device can record cardiac autonomic control in any setting. The VU-AMS proved very amenable to testing in children. https://www.jove.com/v/50073 585 2013-04-29T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51471.jpg Quantification of Global Diastolic Function by Kinematic Modeling-based Analysis of Transmitral Flow via the Parametrized Diastolic Filling Formalism Accurate, causality-based quantification of global diastolic function has been achieved by kinematic modeling-based analysis of transmitral flow via the Parametrized Diastolic Filling (PDF) formalism. PDF generates unique stiffness, relaxation, and load parameters and elucidates 'new' physiology while providing sensitive and specific indexes of dysfunction. https://www.jove.com/v/51471 664 2014-09-01T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67222.jpg Software for Analysis of Heart Rate and Blood Pressure Time-series Data from the Valsalva Maneuver The ValsalvaAnalyzer software includes functions to analyze continuous beat-to-beat electrocardiogram and blood pressure (BP) measurements recorded during the Valsalva maneuver (VM). The computed clinical biomarkers and estimated model outputs provide insight into sympathetic and parasympathetic regulation of heart rate and BP during the VM. https://www.jove.com/v/67222 868 2025-06-27T19:40:00+00:00 JoVE no https://visualize.jove.com/15032659-machine-learning-based-pattern-recognition-applied-to-microarray-data monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40929/40929_article_thumb_40929.jpg Traumatic Brain Injury l: Introduction DefinitionTraumatic brain injury, or TBI, is a disturbance of normal brain function induced by an external mechanical force, such as a direct blow to the head or a penetrating injury. It can affect both brain structure and function, producing a wide range of clinical outcomes. TBI is a heterogeneous condition, meaning its effects may differ based on the type, location, and severity of the injury.Basis of ClassificationTBI is classified based on severity, injury mechanism, or pathophysiology. In... https://www.jove.com/v/40929 88 2026-04-13T23:56:05+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53264.jpg Neuro-rehabilitation Approach for Sudden Sensorineural Hearing Loss This article reports the development of a neuro-rehabilitation approach, "constraint-induced sound therapy (CIST)" for sudden sensorineural hearing loss. The aim of CIST is to prevent maladaptive cortical reorganization by using an enriched acoustic environment. CIST represents a safe, easy, inexpensive, and effective approach to treat sudden sensorineural hearing loss. https://www.jove.com/v/53264 584 2016-01-26T01:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64552.jpg Systematic Hearing Performance Evaluation Process for Adolescents with Cochlear Implantation at Early Ages This paper describes a battery of tests used to clinically assess the hearing performance of adolescent, Mandarin-speaking, experienced cochlear implant users upgraded to a new fine structure coding strategy. The battery of tests include speech in quiet conditions, speech in noisy conditions, lexical tone, and music perception. https://www.jove.com/v/64552 364 2023-03-24T21:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/70048.jpg An Automated System for Sound Localization Testing in Hearing-Impaired Listeners This protocol introduces an automated sound localization testing system with precise loudspeaker placement and integrated response analysis, validated in normal-hearing participants and participants with single-sided deafness. It provides a reproducible method to assess spatial hearing and supports functional classification using the International Classification of Functioning, Disability and Health (ICF) framework. https://www.jove.com/v/70048 472 2026-03-13T20:50:00+00:00 JoVE no https://visualize.jove.com/15043289-neural-network-analysis-of-anal-sphincter-repair monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/61852.jpg Automated Gait Analysis to Assess Functional Recovery in Rodents with Peripheral Nerve or Spinal Cord Contusion Injury Automated gait analysis is a feasible tool to evaluate functional recovery in rodent models of peripheral nerve injury and spinal cord contusion injury. While it requires only one setup to assess locomotor function in various experimental models, meticulous hard- and soft-ware adjustment and training of the animals is highly important. https://www.jove.com/v/61852 391 2020-10-06T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63362.jpg Modified Spared Nerve Injury Surgery Model of Neuropathic Pain in Mice The modified surgery is a simplified method for mouse or rat spared nerve injury model that requires only one ligation and one cut to injure both common peroneal and sural nerves. https://www.jove.com/v/63362 274 2022-01-25T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/69152.jpg Novel Surgical Rodent Model for Studying Neuroma Pain Treatment Options using Targeted Muscle Reinnervation Through the Saphenous Nerve This protocol presents a reproducible rat model using sensory nerves to mimic human neuroma pain and assess surgical treatments, offering a valuable tool for translational neuroma research. https://www.jove.com/v/69152 420 2025-11-14T21:55:00+00:00 JoVE no https://visualize.jove.com/15047205-new-approaches-to-fluorescence-compensation-and-visualization-of-facs-data monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13394.jpg Confocal Fluorescence Microscopy Confocal microscopy is an advanced microscopic technique. The prime advantage of the confocal microscope over other microscopy techniques is its ability to block the out-of-focus light from the illuminated samples using pinholes. It is widely used with fluorescence optics to obtain high-resolution, sharp contrast images. Unlike optical microscopes, confocal microscopes use a focused beam of light laser to scan the entire sample surface at different z-planes. These microscopes are, therefore,... https://www.jove.com/v/13394 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13395.jpg Protein Dynamics in Living Cells Different fluorescence-based techniques are used to study the protein dynamics in living cells. These techniques include FRAP, FRET, and PET. Fluorescent recovery after photobleaching (FRAP) is a fluorescent-protein-based detection technique used to quantify protein movement rates within the cell. This method exposes a small portion of the cell to an intense laser beam. The laser beam causes permanent photobleaching of the fluorophore-tagged proteins in the exposed region. As the bleached... https://www.jove.com/v/13395 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13398.jpg Super-resolution Fluorescence Microscopy Super-resolution fluorescence microscopy (SRFM) provides a better resolution than conventional fluorescence microscopy by reducing the point spread function (PSF). PSF is the light intensity distribution from a point that causes it to appear blurred. Due to PSF, each fluorescing point appears bigger than its actual size, and it is the PSF interference of nearby fluorophores that causes the blurred image. Various approaches to achieving higher resolution through SRFM have recently been developed. https://www.jove.com/v/13398 97 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55119.jpg Open Source High Content Analysis Utilizing Automated Fluorescence Lifetime Imaging Microscopy We present an open source high content analysis (HCA) instrument utilizing automated fluorescence lifetime imaging (FLIM) for assaying protein interactions using Förster resonance energy transfer (FRET) based readouts. Data acquisition for this openFLIM-HCA instrument is controlled by software written in µManager and data analysis is undertaken in FLIMfit. https://www.jove.com/v/55119 570 2017-01-18T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58582.jpg A Fluorescence Fluctuation Spectroscopy Assay of Protein-Protein Interactions at Cell-Cell Contacts This protocol describes a fluorescence fluctuation spectroscopy-based approach to investigate interactions among proteins mediating cell-cell interactions, i.e. proteins localized in cell junctions, directly in living cells. We provide detailed guidelines on instrument calibration, data acquisition and analysis, including corrections to possible artefact sources. https://www.jove.com/v/58582 523 2018-12-01T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66889.jpg Generating and Analyzing High-Parameter Histology Images with Histoflow Cytometry Described here is a method that can be used to image five or more fluorescent parameters by immunofluorescent microscopy. An analysis pipeline for extracting single cells from these images and conducting single-cell analysis through flow cytometry-like gating strategies is outlined, which can identify cell subsets in tissue sections. https://www.jove.com/v/66889 322 2024-06-21T22:00:00+00:00 JoVE no https://visualize.jove.com/15070379-the-alpha-helical-peptide-nucleic-acid-concept-merger-of-peptide-secondary-structure-and-codified-nucleic-acid-recognition monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10678.jpg Protein Organization Overview Proteins are one of the fundamental building blocks of life that carry out many diverse functions in the cell. Proteins are assembled from amino acids. The sequence of amino acids is known as the primary structure of a protein. Local interactions of individual amino acids cause the linear chain to fold into the secondary structures. Interactions of distant amino acids lead to further folding of the protein—the tertiary structure. The assembly of multiple folded chains (subunits) is... https://www.jove.com/v/10678 73 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11470.jpg Amino acids Amino acids are the monomers that comprise proteins. Each amino acid has the same fundamental structure, which consists of a central carbon atom, or the alpha (α) carbon, bonded to an amino group (NH2), a carboxyl group (COOH), and to a hydrogen atom. Every amino acid also has another atom or group of atoms bonded to the central atom known as the R group. There are 20 common amino acids present in proteins, each with a different R group. Variation in the amino acid sequence is responsible for... https://www.jove.com/v/11470 222 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11476.jpg From DNA to Protein The flow of genetic information in cells from DNA to mRNA to protein is described by the central dogma, which states that genes specify the sequence of mRNAs, which in turn specify the sequence of amino acids making up all proteins. The decoding of one molecule to another is performed by specific proteins and RNAs. Because the information stored in DNA is so central to cellular function, it makes intuitive sense that the cell would make mRNA copies of this information for protein synthesis... https://www.jove.com/v/11476 186 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11595.jpg tRNA Activation Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the... https://www.jove.com/v/11595 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12487.jpg Protein Organization Proteins are polymers of amino acid residues. They are versatile and responsible for different cellular functions, including DNA replication, molecular transport, catalysis, and structural support. Proteins have a hierarchical structure comprising at least three levels of organization: primary, secondary, and tertiary structure. Some large proteins have a quaternary structure where individual protein subunits are linked together. The primary structure of a protein is its amino acid sequence. https://www.jove.com/v/12487 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14371.jpg Nucleic Acid Structure The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group on the ribose's second carbon and a hydrogen on the deoxyribose's second carbon. The phosphate residue attaches to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms a 5′ to 3′ phosphodiester linkage. DNA Structure DNA has a double-helix structure. The... https://www.jove.com/v/14371 85 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55779.jpg Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy Structures of supramolecular protein assemblies at atomic resolution are of high relevance because of their crucial roles in a variety of biological phenomena. Herein, we present a protocol to perform high-resolution structural studies on insoluble and non-crystalline macromolecular protein assemblies by magic-angle spinning solid-state nuclear magnetic resonance spectroscopy (MAS SSNMR). https://www.jove.com/v/55779 895 2017-09-17T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61351.jpg Self-Assembly of Gamma-Modified Peptide Nucleic Acids into Complex Nanostructures in Organic Solvent Mixtures This article provides protocols for the design and self-assembly of nanostructures from gamma-modified peptide nucleic acid oligomers in organic solvent mixtures. https://www.jove.com/v/61351 495 2020-06-26T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63841.jpg An Integrated Approach for Microprotein Identification and Sequence Analysis The protocol described here provides detailed instructions on how to analyze genomic regions of interest for microprotein-coding potential using PhyloCSF on the user-friendly UCSC Genome Browser. Additionally, several tools and resources are recommended to further investigate sequence characteristics of identified microproteins to gain insight into their putative functions. https://www.jove.com/v/63841 577 2022-07-12T13:15:00+00:00 JoVE no https://visualize.jove.com/15070506-dynamic-analysis-of-neural-encoding-by-point-process-adaptive-filtering monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2806.jpg Examining Local Network Processing using Multi-contact Laminar Electrode Recording A fundamental issue in our understanding of cortical circuitry is how networks in different cortical layers encode sensory information. Here we describe electrophysiological techniques utilizing multi-contact laminar electrodes to record single-units and local field potentials and present analyses to identify cortical layers. https://www.jove.com/v/2806 820 2011-09-08T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61623.jpg Photodiode-Based Optical Imaging for Recording Network Dynamics with Single-Neuron Resolution in Non-Transgenic Invertebrates This protocol presents a method for imaging neuronal population activity with single-cell resolution in non-transgenic invertebrate species using absorbance voltage-sensitive dyes and a photodiode array. This approach enables a rapid workflow, wherein imaging and analysis can be pursued over the course of a single day. https://www.jove.com/v/61623 618 2020-07-09T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68668.jpg Decoding Natural Behavior from Neuroethological Embedding This protocol gives an integrated framework based on advanced computational neuroethological methods to understand brain coding in naturalistic contexts. https://www.jove.com/v/68668 480 2025-10-03T20:40:00+00:00 JoVE no https://visualize.jove.com/15107023-efficient-prediction-of-alternative-splice-forms-using-protein-domain-homology monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10802.jpg RNA Splicing Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded... https://www.jove.com/v/10802 92 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11503.jpg Conservation of Protein Domains Over Different Proteins Protein domains are small structurally independent units that are part of a single amino acid chain. Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms. A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form... https://www.jove.com/v/11503 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10802.jpg RNA Splicing Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded... https://www.jove.com/v/11587 92 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11622.jpg Alternative RNA Splicing Alternative RNA splicing is the regulated splicing of exons and introns to produce different mature mRNAs from a single pre-mRNA. Unlike in constitutive splicing where a single gene produces a single type of mRNA, alternative splicing allows an organism to produce multiple proteins from a single gene and plays an important role in protein diversity. There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first... https://www.jove.com/v/11622 138 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11503.jpg Conservation of Protein Domains Protein domains are small structurally independent units that are part of a single amino acid chain. Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms. A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form... https://www.jove.com/v/12490 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11622.jpg Alternative RNA Splicing Alternative RNA splicing is the regulated splicing of exons and introns to produce different mature mRNAs from a single pre-mRNA. Unlike in constitutive splicing where a single gene produces a single type of mRNA, alternative splicing allows an organism to produce multiple proteins from a single gene and plays an important role in protein diversity. There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first... https://www.jove.com/v/12567 138 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51845.jpg Detection of Alternative Splicing During Epithelial-Mesenchymal Transition Alternative splicing regulation has been shown to contribute to the epithelial-mesenchymal transition (EMT), an essential cellular program in various physiological and pathological processes. Here we describe a method utilizing an inducible EMT model for the detection of alternative splicing during EMT. https://www.jove.com/v/51845 708 2014-10-09T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54967.jpg Engineering Artificial Factors to Specifically Manipulate Alternative Splicing in Human Cells This report describes a bioengineering method to design and construct novel Artificial Splicing Factors (ASFs) that specifically modulate the splicing of target genes in mammalian cells. This method can be further expanded to engineer various artificial factors to manipulate other aspects of RNA metabolism. https://www.jove.com/v/54967 606 2017-04-26T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62636.jpg Identification of Alternative Splicing and Polyadenylation in RNA-seq Data Alternative splicing (AS) and alternative polyadenylation (APA) expand the diversity of transcript isoforms and their products. Here, we describe bioinformatic protocols to analyze bulk RNA-seq and 3' end sequencing assays to detect and visualize AS and APA varying across experimental conditions. https://www.jove.com/v/62636 515 2021-06-24T20:00:00+00:00 JoVE no https://visualize.jove.com/15161959-coupled-amplification-and-degradation-of-exogenous-rna-injected-in-amphibian-oocytes monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1864.jpg Fertilization of Xenopus oocytes using the Host Transfer Method Procedure for fertilizing Xenopus oocytes by the host transfer method. https://www.jove.com/v/1864 560 2010-11-03T00:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52496.jpg Manipulation and In Vitro Maturation of Xenopus laevis Oocytes, Followed by Intracytoplasmic Sperm Injection, to Study Embryonic Development We describe methods of manipulating Xenopus laevis immature oocytes, in vitro maturation of oocytes to eggs, and intracytoplasmic sperm injection. This protocol allows degradation of some maternal proteins and overexpression of genes of interest at fertilization, and hence is valuable to study roles of specific factors in early embryonic development. https://www.jove.com/v/52496 562 2015-02-09T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52724.jpg Xenopus laevis as a Model to Identify Translation Impairment Protein synthesis control occurs mainly at the translation initiation step, deficiencies in which are linked to diverse disorders. To better understand their etiology, we described here a protocol using Xenopus laevis oocytes assessing the translation of mos transcript in the presence of a mutant of translation initiation factor eIF4G1. https://www.jove.com/v/52724 624 2015-09-27T21:00:00+00:00 JoVE no https://visualize.jove.com/15163504-efficient-generation-and-growth-of-influenza-virus-apr834-from-eight-cdna-fragments monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2057.jpg Generation of Recombinant Influenza Virus from Plasmid DNA Rescue of influenza A viruses from plasmid DNA is a basic and essential experimental technique that allows influenza researchers to generate recombinant viruses to study multiple aspects in the biology of influenza virus, and to be used as potential vectors or vaccines. https://www.jove.com/v/2057 691 2010-08-04T00:10:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11625.jpg Leaky Scanning During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R stands for... https://www.jove.com/v/11625 148 JoVE no https://cloudfront.jove.com/files/ftp_upload/40845/40845_article_thumb_40845.jpg Influenza Influenza is an acute, highly communicable viral disease that affects the respiratory tract and is responsible for seasonal epidemics worldwide. Influenza A is the most prevalent type associated with widespread outbreaks and is subtyped based on two surface glycoproteins: hemagglutinin (H) and neuraminidase (N), as in H1N1. These glycoproteins are essential for viral infectivity, transmission, and immune recognition. Transmission occurs primarily through respiratory droplets and contaminated... https://www.jove.com/v/40845 87 2026-03-12T20:35:52+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52803.jpg Intranasal Administration of Recombinant Influenza Vaccines in Chimeric Mouse Models to Study Mucosal Immunity There is an overall lack of knowledge about how vaccines work. Here we propose the combined use of reverse genetics and bone marrow chimeric mice to gain insight into the early host immune responses to vaccines with a special focus on dendritic cells and T cell immunity. https://www.jove.com/v/52803 639 2015-06-25T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60663.jpg Production of High-Titer Infectious Influenza Pseudotyped Particles with Envelope Glycoproteins from Highly Pathogenic H5N1 and Avian H7N9 Viruses This protocol describes an experimental process to produce high-titer infectious viral pseudotyped particles (pp) with envelope glycoproteins from two influenza A strains and how to determine their infectivity. This protocol is highly adaptable to develop pps of any other type of enveloped viruses with different envelope glycoproteins. https://www.jove.com/v/60663 490 2020-01-15T20:00:00+00:00 JoVE no https://visualize.jove.com/15164227-large-amplification-in-stage-structured-models-arnold-tongues-revisited monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3498.jpg Synthetic, Multi-Layer, Self-Oscillating Vocal Fold Model Fabrication The methodology for fabricating synthetic vocal fold models is described. The models are life-sized and mimic the multi-layer structure of the human vocal folds. Results show the models to self-oscillate at pressures comparable to lung pressure and demonstrate flow-induced vibratory responses that are similar to those of human vocal folds. https://www.jove.com/v/3498 616 2011-12-02T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13162.jpg Amplifying Signals via Enzymatic Cascade When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze the... https://www.jove.com/v/13162 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16576.jpg One-Compartment Open Model: Wagner-Nelson and Loo Riegelman Method for k a Estimation This lesson introduces two critical methods in pharmacokinetics, the Wagner-Nelson and Loo-Riegelman methods, used for estimating the absorption rate constant (ka) for drugs administered via non-intravenous routes. The Wagner-Nelson method relates ka to the plasma concentration derived from the slope of a semilog percent unabsorbed time plot. However, it is limited to drugs with one-compartment kinetics and can be impacted by factors like gastrointestinal motility or enzymatic degradation. On... https://www.jove.com/v/16576 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17825.jpg Steps in the Modeling Process Albert Bandura's theory of observational learning identifies four critical processes: attention, retention, motor reproduction, and reinforcement or motivation. Attention is the first necessary component for observational learning. It involves focusing on what the model is doing and saying. For example, if you decide to take a drawing class to enhance your skills, you need to pay close attention to the instructor's words and hand movements. The characteristics of the model significantly... https://www.jove.com/v/17825 74 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18072.jpg Modeling and Similitude Scaled modeling is a fundamental technique in engineering, enabling the study of large and complex systems by creating smaller, manageable replicas that recreate critical characteristics of the original. In hydrology and civil infrastructure, for example, scaled models of dams help analyze water flow, turbulence, and pressure. This method allows for accurate predictions of real-world behavior within a controlled environment, significantly reducing the cost and time involved in full-scale... https://www.jove.com/v/18072 72 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18073.jpg Typical Model Studies Fluid mechanics model studies often utilize scaled-down systems to predict fluid behavior in full-scale environments, such as river flows, dam spillways, and structures interacting with open surfaces. Maintaining Froude number similarity in river models is crucial, as it replicates surface flow features like wave patterns and velocities. Practical constraints, however, can introduce geometric distortions, impacting how accurately these models represent the real system. Adjustments, such as... https://www.jove.com/v/18073 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18193.jpg Elaborative Rehearsals Elaborative rehearsal is a crucial cognitive strategy that strengthens information encoding in long-term memory by making meaningful connections between new data and pre-existing knowledge. This approach contrasts with maintenance rehearsal, which involves simple repetition without delving into the significance of the information. While maintenance rehearsal might temporarily keep information active in short-term memory, it is less effective for long-term retention. The effectiveness of... https://www.jove.com/v/18193 67 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65140.jpg Objectification of Tongue Diagnosis in Traditional Medicine, Data Analysis, and Study Application The present study employed U-Net and other deep learning algorithms to segment a tongue image and compared the segmentation results to investigate the objectification of tongue diagnosis. https://www.jove.com/v/65140 356 2023-04-14T21:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66796.jpg Augmenting Large Language Models via Vector Embeddings to Improve Domain-Specific Responsiveness In this protocol, foundation large language model response quality is improved via augmentation with peer-reviewed, domain-specific scientific articles through a vector embedding mechanism. Additionally, code is provided to aid in performance comparison across large language models. https://www.jove.com/v/66796 194 2024-12-06T20:20:00+00:00 JoVE no https://visualize.jove.com/15188869-brain-computer-interface-design-for-asynchronous-control-applications-improvements-to-the-lf-asd-asynchronous-brain-switch monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16126.jpg PD Controller: Design In automotive engineering, car suspension systems often employ Proportional Derivative (PD) controllers to enhance performance. PD controllers are utilized to adjust the damping force in response to road conditions. A controller, acting as an amplifier with a constant gain, demonstrates proportional control, with output directly mirroring input. Designing a continuous-data controller requires selecting and linking components like adders and integrators, which are fundamental in Proportional,... https://www.jove.com/v/16126 86 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53558.jpg SSVEP-based Experimental Procedure for Brain-Robot Interaction with Humanoid Robots The overall goal of this method is to establish an SSVEP-based experimental procedure by integrating multiple software programs to enable the study of brain-robot interaction with humanoid robots, which is prospective in assisting the sick and elderly as well as performing unsanitary or dangerous jobs. https://www.jove.com/v/53558 661 2015-11-24T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61943.jpg Real-Time Proxy-Control of Re-Parameterized Peripheral Signals using a Close-Loop Interface We present protocols and methods of analyses to build co-adaptive interfaces that stream, parameterize, analyze, and modify human body and heart signals in close-loop. This setup interfaces signals derived from the peripheral and central nervous systems of the person with external sensory inputs to help track biophysical change. https://www.jove.com/v/61943 714 2021-05-08T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67601.jpg Brain-Computer Interface-controlled Upper Limb Robotic System for Enhancing Daily Activities in Stroke Patients This study introduces a brain-computer interface (BCI) system for stroke patients, which combines electroencephalography and electrooculography signals to control an upper limb robotic hand, enhancing daily activities. The evaluation used the Berlin Bimanual Test for Stroke (BeBiTS). https://www.jove.com/v/67601 371 2025-04-18T20:10:00+00:00 JoVE no https://visualize.jove.com/15212595-autogenomics-inc monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/10966/10966_article_thumb_10966.jpg Phylogeny Phylogeny is concerned with the evolutionary diversification of organisms or groups of organisms. A group of organisms with a name is called a taxon (singular). Taxa (plural) can span different levels of the evolutionary hierarchy. For instance, the group containing all birds is a taxon (comprising the class Aves), and the group of all species of daisies (the genus Bellis) is a taxon. Phylogenies can likewise include just one genus (i.e., depict species relationships) or span an entire... https://www.jove.com/v/10966 83 2026-06-01T13:28:29+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11122.jpg Genomics Genomics is the science of genomes: it is the study of all the genetic material of an organism. In humans, the genome consists of information carried in 23 pairs of chromosomes in the nucleus, as well as mitochondrial DNA. In genomics, both coding and non-coding DNA is sequenced and analyzed. Genomics allows a better understanding of all living things, their evolution, and their diversity. It has a myriad of uses: for example, to build phylogenetic trees, to improve productivity and... https://www.jove.com/v/11122 122 JoVE no https://cloudfront.jove.com/files/ftp_upload/19557/19557_article_thumb_19557.jpg Modern Molecular Taxonomy Advancements in molecular biology have revolutionized the identification and characterization of bacteria, with multiple methods leveraging DNA sequencing for enhanced precision. As sequencing technologies improve and costs decline, these approaches are increasingly used in clinical, environmental, and evolutionary studies.Multilocus Sequence Typing (MLST) examines several housekeeping genes, essential chromosomal genes encoding cellular functions, to distinguish strains. Approximately... https://www.jove.com/v/19557 89 2025-06-12T16:19:23+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19558/19558_article_thumb_19558.jpg Applications of Molecular Taxonomy Molecular taxonomy has revolutionized the understanding and classification of bacteria, providing precise insights into their diversity, evolutionary relationships, and ecological roles. By utilizing molecular techniques such as DNA sequencing and fingerprinting, researchers have made significant strides in various fields related to bacterial studies.Resolving Taxonomic AmbiguitiesMolecular taxonomy has been instrumental in distinguishing closely related bacterial species initially thought to... https://www.jove.com/v/19558 80 2025-06-12T16:19:34+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19582/19582_article_thumb_19582.jpg Red Algae Red algae, also known as rhodophytes, are primarily found in marine environments, though some species inhabit freshwater and terrestrial ecosystems. These organisms exist in both unicellular and multicellular forms, with some multicellular varieties reaching macroscopic sizes.As phototrophic organisms, red algae contain chlorophyll a; however, their chloroplasts lack chlorophyll b. Instead, they possess phycobiliproteins, which serve as major light-harvesting pigments, similar to those found in... https://www.jove.com/v/19582 83 2025-06-12T16:26:52+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19852/19852_article_thumb_19852.jpg Other Algae The group Stramenopiles include some phototrophic microorganisms. Members of this group possess flagella covered in numerous short, hairlike extensions, a feature that inspired the group's name, derived from the Latin words for "straw" and "hair." Some of the main categories of Stramenopiles include diatoms, golden algae, and brown algae.Diatoms are unicellular, photosynthetic eukaryotes, with over 200 known genera. They play a key role in the planktonic communities of both marine and... https://www.jove.com/v/19852 79 2025-06-12T13:31:27+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51346.jpg Identification of Novel Genes Associated with Alginate Production in Pseudomonas aeruginosa Using Mini- himar1 Mariner Transposon-mediated Mutagenesis Here we describe a protocol using the mini-himar1 mariner transposon-mediated mutagenesis for generating a high-density insertion mutant library to screen, isolate and identify novel alginate regulators in the prototypic Pseudomonas aeruginosa strain PAO1. https://www.jove.com/v/51346 537 2014-03-11T04:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59760.jpg Use of Alu Element Containing Minigenes to Analyze Circular RNAs We clone and analyze reporter genes generating circular RNAs. These reporter genes are larger than constructs to analyze linear splicing and contain Alu elements. To investigate the circular RNAs, the constructs are transfected into cells and resulting RNA is analyzed using RT-PCR after removal of linear RNA. https://www.jove.com/v/59760 790 2020-03-10T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61913.jpg High-Throughput Metabolic Profiling for Model Refinements of Microalgae This protocol demonstrates the use of a phenotype microarray (PM) technology platform to define metabolic requirements of Chlamydomonas reinhardtii, a green microalga, and refine an existing metabolic network model. https://www.jove.com/v/61913 667 2021-12-04T21:00:00+00:00 JoVE no https://visualize.jove.com/15225298-euroconference-on-the-biology-of-type-iv-secretion-processes-bacterial-gates-into-the-outer-world monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11886.jpg Receptor-mediated Endocytosis Receptor-mediated endocytosis is when bulk amounts of specific molecules are imported into a cell after binding to cell surface receptors. The molecules bound to these receptors are taken into the cell through inward folding of the cell surface membrane, which is eventually pinched off into a vesicle within the cell. Structural proteins, such as clathrin, coat the budding vesicle. Clathrin-Mediated Endocytosis of LDL One well-characterized example of receptor-mediated endocytosis is the... https://www.jove.com/v/11886 80 JoVE no https://cloudfront.jove.com/files/ftp_upload/19529/19529_article_thumb_19529.jpg Bacterial Translocation and Protein Secretion Bacterial protein secretion involves translocation systems to ensure proteins reach their designated locations, including the plasma membrane, periplasm, outer membrane, or the external environment. These translocation systems are vital for bacterial physiology, supporting processes like membrane assembly, enzymatic activity in the periplasm, and interactions with the external environment. The division of labor between Sec and Tat pathways ensures efficiency in handling proteins with diverse... https://www.jove.com/v/19529 86 2025-06-12T16:13:29+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19530/19530_article_thumb_19530.jpg Gram-negative Bacterial Protein Secretion Systems Gram-negative bacteria utilize sophisticated protein secretion systems to transport proteins across their double-membrane envelope into the extracellular environment or host cells. Based on their mechanism of action, these systems are classified into one-step and two-step pathways.One-Step Secretion Systems (Types I, III, IV, and VI)One-step secretion systems bypass the periplasm entirely, forming a continuous channel that spans both the inner and outer membranes:Type I Secretion System (T1SS):... https://www.jove.com/v/19530 77 2025-06-12T16:13:43+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19551/19551_article_thumb_19551.jpg Mechanism of Conjugation Bacterial conjugation is a mechanism of horizontal gene transfer that enables the exchange of genetic material between bacterial cells through direct contact. This process is facilitated by a donor cell carrying a conjugative plasmid, which encodes genes necessary for pilus formation, DNA replication, and transfer. The conjugative plasmid plays a central role in initiating and executing the transfer of genetic material.The tra region of the conjugative plasmid encodes proteins responsible for... https://www.jove.com/v/19551 79 2025-06-12T16:18:14+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40811/40811_article_thumb_40811.jpg Bacterial Toxins Bacterial toxins are sophisticated virulence factors that enable pathogenic bacteria to interact with, invade, and damage host tissues. These toxins fall broadly into two types: protein exotoxins, which are secreted into the environment and target specific host receptors, and lipopolysaccharide endotoxins, which are structural components of the bacterial outer membrane released primarily during bacterial lysis or membrane shedding. Exotoxins generally act more selectively, binding to cell... https://www.jove.com/v/40811 72 2026-03-12T20:36:10+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40813/40813_article_thumb_40813.jpg Regulation of Bacterial Virulence Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental... https://www.jove.com/v/40813 88 2026-03-12T20:36:13+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50103.jpg A Visual Assay to Monitor T6SS-mediated Bacterial Competition We describe a qualitative assay to monitor bacterial competition mediated by the Pseudomonas aeruginosa type VI secretion system (T6SS). The assay relies on the survival/killing of Escherichia coli target cells carrying a lacZ-reporter. This technique is adjustable to assess the bactericidal/bacteriostasis activity of T6SS-proficient microorganisms. https://www.jove.com/v/50103 525 2013-03-20T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51217.jpg Monitoring the Assembly of a Secreted Bacterial Virulence Factor Using Site-specific Crosslinking This article illustrates the use of pulse-chase radio labeling in combination with site-specific photocrosslinking to monitor interactions between a protein of interest and other factors in E. coli. Unlike traditional chemical cross-linking methods, this approach generates high resolution “snapshots” of an ordered assembly pathway in a living cell. https://www.jove.com/v/51217 693 2013-12-17T22:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54854.jpg Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation Here, we present a protocol to knockout a gene of interest involved in plasmid conjugation and subsequently analyze the impact of its absence using mating assays. The function of the gene is further explored to a specific region of its sequence using deletion or point mutations. https://www.jove.com/v/54854 641 2017-01-04T20:30:00+00:00 JoVE no https://visualize.jove.com/15261653-models-of-cell-signaling-pathways monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10721.jpg Intracellular Signaling Cascades Once a ligand binds to a receptor, the signal is transmitted through the membrane and into the cytoplasm. The continuation of a signal in this manner is called signal transduction. Signal transduction only occurs with cell-surface receptors, which cannot interact with most components of the cell, such as DNA. Only internal receptors can interact directly with DNA in the nucleus to initiate protein synthesis. When a ligand binds to its receptor, conformational changes occur that affect the... https://www.jove.com/v/10721 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13155.jpg Overview of Cell Signaling Despite the protective membrane that separates a cell from the environment, cells need the ability to detect and respond to environmental changes. Additionally, cells often need to communicate with one another. Unicellular and multicellular organisms use a variety of cell signaling mechanisms to communicate with the environment. Cells respond to many types of information, often through receptor proteins positioned on the membrane. For example, skin cells respond to and transmit touch... https://www.jove.com/v/13155 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13160.jpg Interactions Between Signaling Pathways Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli. Convergence and divergence, and cross-talk between signaling pathways Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response... https://www.jove.com/v/13160 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13163.jpg Diversity in Cell Signaling Responses The physiological function of a cell and cellular communication are outcomes of a range of extrinsic signals, intracellular signaling pathways, and cellular responses. No two cell types express the same repertoire of signaling components. Receptors are highly selective for their cognate ligands, but once activated, they can alter multiple cellular processes such as DNA transcription, protein synthesis, and metabolic activity. Graded and Abrupt Responses Some signaling systems generate... https://www.jove.com/v/13163 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13209.jpg MAPK Signaling Cascades Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP... https://www.jove.com/v/13209 67 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13155.jpg Overview of Cell Signaling Despite the protective membrane that separates a cell from the environment, cells need the ability to detect and respond to environmental changes. Additionally, cells often need to communicate with one another. Unicellular and multicellular organisms use a variety of cell signaling mechanisms to communicate with the environment. Cells respond to many types of information, often through receptor proteins positioned on the membrane. For example, skin cells respond to and transmit touch... https://www.jove.com/v/13956 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54869.jpg A Web Tool for Generating High Quality Machine-readable Biological Pathways PathWhiz is a comprehensive, online pathway drawing tool for generating biochemical and biological pathways. It uses publicly accessible databases and easily expandable palettes consisting of pre-drawn pathway components. This protocol describes how to easily build new pathways, replicate and edit existing pathways, and propagate previously drawn pathways to different organisms. https://www.jove.com/v/54869 481 2017-02-08T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55113.jpg The Power of Simplicity: Sea Urchin Embryos as in Vivo Developmental Models for Studying Complex Cell-to-cell Signaling Network Interactions This video article details a straightforward in vivo methodology that can be used to systematically and efficiently characterize components of complex signaling pathways and regulatory networks in many invertebrate embryos. https://www.jove.com/v/55113 454 2017-02-16T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65733.jpg Optogenetic Signaling Activation in Zebrafish Embryos Optogenetic manipulation of signaling pathways can be a powerful strategy to investigate how signaling is decoded in development, regeneration, homeostasis, and disease. This protocol provides practical guidelines for using light-oxygen-voltage sensing domain-based Nodal and bone morphogenic protein (BMP) signaling activators in the early zebrafish embryo. https://www.jove.com/v/65733 438 2023-10-27T21:30:00+00:00 JoVE no https://visualize.jove.com/15288875-an-insight-into-australian-nurses-experience-of-withdrawalwithholding-of-treatment-in-the-icu monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12948.jpg International Nursing Organizations I International Nursing Organization (ICN) is a global union of national nurses' organizations. Individual nurses can be a part of ICN through member organizations. Each member organization strives to ensure quality nursing care, sound health policies, the advancement of nursing knowledge, respect for the profession, and a satisfied and competent nursing workforce. ICN member organizations work to advance the field of nursing and healthcare via policies, partnerships, lobbying, professional... https://www.jove.com/v/12948 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12957.jpg Current Trends in Nursing I Current trends in nursing include: The changes that have shaped the profession. Guided legislation. The functioning of the present healthcare system. With an increase in the aging population worldwide, it is crucial to train nurses from all healthcare settings to identify approaches that enable older adults to live independently. Nurses also provide essential care and education to manage multiple chronic conditions and ensure the elderly in long-term care receive optimal care and... https://www.jove.com/v/12957 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12958.jpg Current Trends in Nursing II Trends in nursing are multifactorial and associated with changes in society, within the nursing profession, and in other professions. Notably, telehealth and remote nursing contribute to successful healthcare delivery for numerous patients and help reduce stress for nurses due to nursing shortages. Nurses can reach patients, monitor their conditions, and interact with them using computers, audio, visual accessories, and telephones—for example, remote patient monitoring systems. Likewise,... https://www.jove.com/v/12958 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14129.jpg Nursing Ethical Principles II Ethical principles are essential in guiding nurses to fulfill their responsibilities, focusing on the quality of nursing care and decision-making. These principles, including autonomy, beneficence, non-maleficence, justice, and fidelity, shape the ethical framework within healthcare settings. Consider the following scenario, which illustrates how these principles are applied in the care of Mr. John, a fifty-year-old teacher diagnosed with metastatic liver cancer. Initially, Mr. John's cancer... https://www.jove.com/v/14129 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14132.jpg Ethical Issues Nurses are essential in patient care, upholding the ethical principles of their profession and effectively navigating ethical dilemmas. Neglecting ethical issues can lead to inadequate patient care, compromised therapeutic relationships, and moral distress among healthcare workers. Ethical Concerns in Healthcare: • Paternalism: Nurses often encounter situations where they must act without patient consent to safeguard their well-being or prevent harm. A common example occurs in cases of elder... https://www.jove.com/v/14132 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14140.jpg Nurses' Legal Responsibilities III Nurse-to-nurse relationships are legally required to adhere to professional standards, ensuring a respectful and positive working environment. Professional conduct demands that nurses treat all colleagues respectfully and courteously, fostering a productive, supportive workplace. Nurses must actively eliminate bullying, discrimination, and harassment to maintain a safe and inclusive environment. Cultivating a culture of collaboration and mutual respect among nurses transcends mere enhancement... https://www.jove.com/v/14140 76 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57972.jpg Objective Nociceptive Assessment in Ventilated ICU Patients: A Feasibility Study Using Pupillometry and the Nociceptive Flexion Reflex Pain assessment in anesthetized patients who cannot communicate with the outside world in any way remains challenging despite the development of innovative objective pain evaluation tools. In this project, the pupillary dilation reflex and the nociception flexion reflex are assessed in critically ill, mechanically ventilated adult patients. https://www.jove.com/v/57972 364 2018-07-04T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62747.jpg An In Vivo Mouse Model of Total Intravenous Anesthesia During Cancer Resection Surgery This paper describes a method for modeling total intravenous anesthesia (TIVA) during cancer resection surgery in mice. The goal is to replicate key features of anesthesia delivery to patients with cancer. The method allows investigation of how anesthetic technique affects cancer recurrence after resection surgery. https://www.jove.com/v/62747 400 2021-06-08T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66756.jpg Monitoring Lung Function with Electrical Impedance Tomography in the Intensive Care Unit Electrical Impedance Tomography is a non-invasive, radiation-free, real-time pulmonary ventilation monitoring tool. By measuring impedance changes in the thorax, it can visualize the distribution of air on a breath-by-breath basis. Initially intended for ventilation monitoring, electrical impedance tomography can also measure perfusion via intravenous injection of a saline solution. https://www.jove.com/v/66756 356 2024-09-06T20:10:00+00:00 JoVE no https://visualize.jove.com/15320437-the-information-wave-hypothesis-of-a-pain monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1092.jpg Determining heat and mechanical pain threshold in inflamed skin of human subjects Algorithms assessing heat and mechanical pain thresholds in experimentally inflamed skin of human study subjects are shown. The two pain testing paradigms independently examine nociceptive processing by the two major peripheral nerve fiber populations transmitting pain, i.e., non-myelinated C fibers and small myelinated A-delta fibers. https://www.jove.com/v/1092 801 2009-01-14T08:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10860.jpg Thermosensation Peripheral thermosensation is the perception of external temperature. A change in temperature (on the surface of the skin and other tissues) is detected by a family of temperature-sensitive ion channels called Transient Receptor Potential, or TRP, receptors. These receptors are located on free nerve endings. Those detecting cold temperatures are closer to the surface of the skin than the nerve endings detecting warmth. These thermoTRP channels, while temperature selective, have relatively... https://www.jove.com/v/10860 103 2025-10-23T18:49:21+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10873.jpg Nociception Nociception—the ability to feel pain—is essential for an organism’s survival and overall well-being. Noxious stimuli such as piercing pain from a sharp object, heat from an open flame, or contact with corrosive chemicals are first detected by sensory receptors, called nociceptors, located on nerve endings. Nociceptors express ion channels that convert noxious stimuli into electrical signals. When these signals reach the brain via sensory neurons, they are perceived as pain. Thus, pain helps the... https://www.jove.com/v/10873 104 2025-10-23T18:49:14+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12785.jpg Sound Waves Sound waves can be thought of as fluctuations in the pressure of a medium through which they propagate. Since the pressure also makes the medium's particles vibrate along its direction of motion, the waves can be modeled as the displacement of the medium's particles from their mean position. Sound waves are longitudinal in most fluids because fluids cannot sustain any lateral pressure. In solids, however, shear forces help in propagating the disturbance in the lateral direction as well. Hence,... https://www.jove.com/v/12785 61 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14014.jpg Blood and Nerve Supply to the Bones Bones are dynamic organs that require a rich supply of oxygen and nutrients. Around 5% to 10% of the cardiac output supplies blood to the bones. A typical long bone has three main sources: the nutrient artery, the metaphyseal and epiphyseal arteries, and the periosteal arteries. Nutrient Artery The nutrient artery is the main blood vessel that enters the diaphysis via the nutrient foramen. While most long bones have only one nutrient foramen, large bones, such as the femur, may have two. This... https://www.jove.com/v/14014 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15185.jpg Analgesia and Pain Management Pain is critical to various clinical pathologies, provoking an urgent need for effective management. Pain, whether acute or chronic, is a complex neurochemical process. Its alleviation depends on the type, with nonopioid analgesics effective for mild to moderate pain, such as musculoskeletal or inflammatory pain, while neuropathic pain responds best to anticonvulsants, tricyclic antidepressants, or serotonin/norepinephrine reuptake inhibitors. For severe acute or chronic pain, opioids may be... https://www.jove.com/v/15185 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17780.jpg Pain Pain serves as a critical warning signal that alerts the body to potential or actual harm. When mechanical pressure on the skin is intense, such as from a sharp pinch, the sensation transitions from touch to pain. Similarly, extreme temperatures, like a hot pot handle, convert the sensation of heat into pain. Pain can also result from overstimulation of other senses, such as blinding light, loud noise, or the intense heat from habañero peppers. This ability to sense pain is essential for... https://www.jove.com/v/17780 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55228.jpg Psychophysically-anchored, Robust Thresholding in Studying Pain-related Lateralization of Oscillatory Prestimulus Activity Psychophysical methods such as the QUEST estimation procedure can efficiently yield robust estimates of the stimulation intensity at which nonpainful sensations transition into painful sensations. By stimulating repeatedly at the threshold intensity, the variability in rating responses can directly be attributed to perceptual classifications in subsequent analyses. https://www.jove.com/v/55228 448 2017-01-21T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59057.jpg Multi-Modal Signals for Analyzing Pain Responses to Thermal and Electrical Stimuli This article focuses on the experimental elicitation of pain through heat (thermal) and electrical stimulation while recording physiological, visual, and paralinguistic responses. It aims at collecting valid multimodal data for analyzing pain based on its intensity, quality, and... https://www.jove.com/v/59057 556 2019-04-05T20:00:00+00:00 JoVE no https://visualize.jove.com/15321068-processing-of-complex-stimuli-and-natural-scenes-in-the-auditory-cortex monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10853.jpg Hearing When we hear a sound, our nervous system is detecting sound waves—pressure waves of mechanical energy traveling through a medium. The frequency of the wave is perceived as pitch, while the amplitude is perceived as loudness. Sound waves are collected by the external ear and amplified as they travel through the ear canal. When sounds reach the junction between the outer and middle ear, they vibrate the tympanic membrane—the eardrum. The resulting mechanical energy causes the attached ossicles—a... https://www.jove.com/v/10853 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14907.jpg Motor and Sensory Areas of the Cortex The cerebral cortex, the brain's outermost layer, is pivotal in processing complex cognitive tasks, emotions, and various sensory inputs and executing voluntary motor activities. This intricate structure is divided into three primary functional areas: the motor areas, sensory areas, and association areas. Motor Areas The motor areas located in the frontal lobe are central to controlling voluntary movements. This region is further subdivided into the primary motor cortex and the premotor cortex. https://www.jove.com/v/14907 74 2025-06-13T03:40:51+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14908.jpg Association Areas of the Cortex Association areas are regions of the cerebral cortex that do not have a specific sensory or motor function. Instead, they integrate and interpret information from various sources to enable higher cognitive processes such as memory, learning, and decision-making. Some key association areas include the following: Prefrontal Association Area: This area is located in the frontal lobe and is involved in planning, decision-making, and moderating social behavior. It connects with primary motor areas,... https://www.jove.com/v/14908 81 2025-06-13T03:41:09+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14970.jpg Auditory Pathway Auditory pathways constitute the complex neural circuits responsible for transmitting and interpreting auditory information from the peripheral auditory system to the brain. Sound waves are initially captured by the outer ear, funneled through the ear canal, and reach the tympanic membrane (eardrum). These vibrations are transmitted via the middle ear's ossicles to the inner ear's cochlea. When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking the... https://www.jove.com/v/14970 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17749.jpg Somatosensory, Motor, and Association Cortex The somatosensory cortex in the parietal lobes is crucial for interpreting sensory data such as touch, temperature, and proprioception. The somatosensory cortex, situated in the parietal lobes, plays a vital role in interpreting sensory information like touch, temperature, and proprioception—awareness of body position. This specialized brain region features an organized structure wherein neurons at the top primarily process sensations originating from the lower body. In contrast, those at the... https://www.jove.com/v/17749 83 2026-03-20T07:53:54+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17771.jpg Auditory Perception The auditory system is essential for sound perception, utilizing various critical structures. When sound waves enter the outer ear, they travel through the ear canal and cause the eardrum to vibrate. These vibrations are then transmitted to the middle ear, where three tiny bones – the malleus, incus, and stapes – amplify the sound. This amplification is crucial, as it ensures that the sound vibrations are strong enough to be conveyed to the inner ear. These vibrations then reach the cochlea, a... https://www.jove.com/v/17771 77 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53002.jpg Combined Shuttle-Box Training with Electrophysiological Cortex Recording and Stimulation as a Tool to Study Perception and Learning Shuttle-box avoidance learning is well-established in behavioral neuroscience. This protocol describes how shuttle-box learning in rodents can be combined with site-specific electrical intracortical microstimulation (ICMS) and simultaneous chronical in vivo recordings as a tool to study multiple aspects of learning and perception. https://www.jove.com/v/53002 523 2015-10-22T09:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56429.jpg Stereotactically-guided Ablation of the Rat Auditory Cortex, and Localization of the Lesion in the Brain We describe a method for the stereotactically-guided location, exposure, and ablation of the auditory cortex in rats. The localization of the ablation is assessed using a coordinate map postmortem. https://www.jove.com/v/56429 569 2017-10-11T07:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67983.jpg Multiscale Investigations of Cortical Processing by Integrating Laminar Polytrodes and Optogenetics with Micro Electrocorticography in Rodents Here, we present two protocols for high-density micro-electrocorticography (µEcoG) recording in rats and mice, including surgical, implantation, and recording methods. µECoG recordings are performed in combination with either laminar polytrode recording in the rat auditory cortex or with optogenetic manipulation of neural activity in the mouse somatosensory cortex. https://www.jove.com/v/67983 472 2025-05-23T08:00:00+00:00 JoVE no https://visualize.jove.com/15321708-spots-and-stripes-the-evolution-of-repetition-in-visual-signal-form monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/127.jpg Testing Visual Sensitivity to the Speed and Direction of Motion in Lizards Testing visual sensitivity in lizards using an operant conditioning paradigm that employs video playback of random-dot kinematograms and computer-generated invertebrates. https://www.jove.com/v/127 750 2006-12-14T08:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11296.jpg Interference and Diffraction Interference is a characteristic phenomenon exhibited by waves. When two electromagnetic waves interact with their peaks and troughs coinciding, a resulting wave with enhanced amplitude is produced. This is known as constructive interference. In this case, the two waves interacting are in phase with each other. Alternatively, if the two waves coincide and interact in a way such that the trough of one wave coincides with the peak of the other (in an out of phase manner), the resultant wave will... https://www.jove.com/v/11296 138 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11536.jpg Position-effect Variegation In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.<br... https://www.jove.com/v/11536 152 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11934.jpg Signal Sequences and Sorting Receptors Signal sequences are short amino acid sequences that guide newly synthesized proteins to their proper location within the cell. Classical signal sequences are fifteen to sixty amino acids long and present at the N-terminus of a polypeptide chain. Each signal sequence has a conserved segment of basic residues towards their N terminus, a hydrophobic core, and a C-terminus rich in polar residues. The C-terminus also contains a signal cleavage site and features a -3 -1 sequence motif. The -3-1... https://www.jove.com/v/11934 101 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16039.jpg Even and Odd Signals An even signal, whether in continuous-time or discrete-time, is defined by its symmetry with its time-reversed version. Mathematically, this is represented as for continuous-time signals and for discrete-time signals. Even signals exhibit symmetry around the vertical axis, meaning the signal for negative time values mirrors that for positive time values. In contrast, a signal is termed odd if it does not match its time-reversed counterpart, represented by for continuous-time signals and for... https://www.jove.com/v/16039 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16175.jpg Traveling Waves: Lossless Lines The provided content explores the behavior of traveling waves on single-phase lossless transmission lines. It begins with a single-phase two-wire lossless transmission line of length Δx, characterized by a loop inductance LH/m and a line-to-line capacitance C F/m. These parameters result in a series inductance LΔx and a shunt capacitance CΔx. The voltage v(x,t) and current i(x,t) at any position x and time t on the line are expressed using Kirchhoff's Voltage Law (KVL) and Kirchhoff's Current... https://www.jove.com/v/16175 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18043.jpg Streamlines, Streaklines, and Pathlines A streamline represents the trajectory that is always tangent to the fluid's velocity vector at any given point. The velocity of a fluid particle is always directed along the streamline, ensuring the particle continuously follows the streamline's path. Streamlines are particularly useful for visualizing the overall direction of flow in a fluid system, and they provide an instantaneous representation of the flow's velocity field. In steady flow, where conditions do not change over time,... https://www.jove.com/v/18043 78 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62285.jpg RBDT: A Computerized Task System based in Transposition for the Continuous Analysis of Relational Behavior Dynamics in Humans RBDT integrates behavioral patterns based on discrete responses (e.g., stimuli selection, placement of figures) and continuous responses (e.g., tracking of cursor movements, figure dragging) to study relational behavior with humans. RBDT is a challenging task based on transposition, in which the participant sets up stimuli compounds with a relational criterion (more/less than). https://www.jove.com/v/62285 669 2021-07-17T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68576.jpg Applying Permanent, Robust Stenciled Patterns of Fine Particles to Elastomeric Surfaces We present a method to apply permanent markings and patterns to silicone surfaces by adhering fine particles to the surface. The markings can be either a recognizable design or a random speckle pattern such as those used in digital image correlation. https://www.jove.com/v/68576 432 2025-07-08T21:10:00+00:00 JoVE no https://visualize.jove.com/15329585-retrograde-air-embolization-during-routine-radial-artery-catheter-flushing-in-adult-cardiac-surgical-patients-an-ultrasound-study monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17882.jpg Imaging Studies for Cardiovascular System II:Types of Echocardiography Echocardiography plays a role in assessing cardiac health and detecting heart conditions, with various types providing critical insights for diagnosis and treatment. Types of Echocardiography Transthoracic Echocardiography (TTE) TTE is the most common type of echocardiogram which involves placing a transducer on the patient's chest, emitting sound waves to create heart images. TTE is invaluable for evaluating the heart's size, structure, and motion, making it particularly useful for diagnosing... https://www.jove.com/v/17882 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17883.jpg Imaging Studies for Cardiovascular System III: X-Ray The most common cardiovascular diagnostic test is an X-ray. It produces images of the heart, blood vessels, and adjacent structures. Definition and Purpose An X-ray, or radiograph, is a non-invasive method that uses ionizing radiation to take images of internal structures. It is mainly used in cardiac imaging to examine the heart, lungs, and major blood vessels, aiming to identify abnormalities in the heart's size, shape, and position, such as heart failure, congenital defects, and vascular... https://www.jove.com/v/17883 80 JoVE no https://cloudfront.jove.com/files/ftp_upload/17888/17888_article_thumb_17888.jpg Cardiac Catheterization I: Pre-Procedure Overview Cardiac catheterization is an invasive diagnostic technique used to identify and evaluate structural and functional diseases of the heart and major blood vessels. This technique diagnoses congenital heart disease, coronary artery disease, valvular heart disease, and coronary spasms and assesses ventricular function. It helps guide treatment decisions, including the need for revascularization procedures like percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) and... https://www.jove.com/v/17888 88 2025-06-19T16:14:01+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17889/17889_article_thumb_17889.jpg Cardiac Catheterization II: Right Heart Catheterization Right Heart Catheterization: An OverviewRight heart catheterization is an invasive diagnostic procedure that measures right-sided cardiac and pulmonary artery pressures, calculates cardiac output, and identifies intracardiac shunts. It provides detailed hemodynamic data essential for diagnosing and managing various cardiovascular conditions, such as pulmonary hypertension.Access SitesCommon access sites for right heart catheterization include the internal jugular vein in the neck region, the... https://www.jove.com/v/17889 81 2025-06-19T16:14:22+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17890/17890_article_thumb_17890.jpg Cardiac Catheterization III: Left Heart Catheterization Left heart catheterization is an invasive diagnostic procedure used to evaluate the function and structure of the left side of the heart. It is generally performed to diagnose and treat cardiovascular conditions such as valve abnormalities, coronary artery disease, and congenital heart defects.Diagnostic and therapeutic purposesLeft heart catheterization serves various diagnostic and therapeutic purposes, including:Assessing coronary artery bypass grafts.Evaluating coronary artery disease in... https://www.jove.com/v/17890 84 2026-01-28T21:01:00+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18494/18494_article_thumb_18494.jpg Imaging Studies VII: Vascular Imaging DefinitionRenal angiography, also known as renal arteriography, is an imaging technique used to obtain a comprehensive view of blood flow and the vascular structure of blood vessels in the kidneys and surrounding areas.PurposeRenal angiography detects blood vessel abnormalities in the kidneys, such as aneurysms, stenosis, thrombosis, vascular tumors, and renal artery stenosis. It evaluates kidney function and guides interventional treatments like angioplasty or stent placement.Pre-Procedure... https://www.jove.com/v/18494 79 2025-06-19T16:30:31+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52606.jpg Non-fluoroscopic Catheter Tracking for Fluoroscopy Reduction in Interventional Electrophysiology Radiation exposure is an underestimated risk in complex ablation procedures. Here, we describe a protocol to significantly decrease fluoroscopy time and dosage for both the patient and the lab staff by using a novel non-fluoroscopic catheter visualization system. https://www.jove.com/v/52606 646 2015-05-26T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61109.jpg Transradial Access Chemoembolization for Hepatocellular Carcinoma Patients Transarterial chemoembolization (TACE) is the standard therapy for patients in the intermediate stage of hepatocellular carcinoma and is typically performed through femoral artery access. Compared with transfemoral access, transradial access (TRA) can decrease the rate of bleeding complications and improve patient tolerance. A method is presented here to perform transarterial chemoembolization via radial artery access. https://www.jove.com/v/61109 331 2020-09-20T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64956.jpg Reduction of Radiation Exposure during Endovascular Treatment of Peripheral Arterial Disease Combining Fiber Optic RealShape Technology and Intravascular Ultrasound Described here is a stepwise method of combining Fiber Optic RealShape technology and intravascular ultrasound to show the potential of merging both techniques, in view of the reduction of radiation exposure and improvement of navigation tasks and treatment success during an endovascular procedure for the treatment of peripheral arterial disease. https://www.jove.com/v/64956 828 2023-04-21T19:10:00+00:00 JoVE no https://visualize.jove.com/15371789-the-new-malone-antegrade-continence-enema-automatic-instillation-device-allows-independence-and-decreases-flush-times monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16444.jpg Inflammatory Bowel Disease V: Surgical Management Surgical interventions for inflammatory bowel disease (IBD), which includes ulcerative colitis and Crohn's disease, are essential in managing symptoms and addressing complications. The selection of surgical procedures is contingent upon the specific conditions and complications that stem from these illnesses. Here are some common surgical interventions for IBD: Strictureplasty Proctocolectomy or total colectomy with ileostomy Restorative proctocolectomy with Ileal pouch-anal anastomosis<br... https://www.jove.com/v/16444 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16512.jpg Methods for Studying Drug Absorption: In situ In situ experiments, such as the Doluisio method and Single-Pass Perfusion technique, provide critical insights into drug uptake by simulating in vivo conditions for drug absorption. The Doluisio method involves perfusing a prepared segment of a rat's small intestine with a solution of radiolabeled drug and a non-absorbable marker. This helps to differentiate between absorbed and non-absorbed drug concentrations. The intestinal segment is connected at both ends using tubing and syringes,... https://www.jove.com/v/16512 69 JoVE no https://cloudfront.jove.com/files/ftp_upload/17183/17183_article_thumb_17183.jpg Drug Accumulation During Multiple Dosing: Intermittent IV Infusions Intermittent intravenous (IV) infusion is a method of drug administration where medications are delivered over short infusion periods followed by intervals of no drug delivery. This approach helps to prevent sustained high drug concentrations in the bloodstream, reducing the risk of adverse effects associated with prolonged exposure. Unlike continuous infusion, steady-state concentrations may not be achieved during a single dosing cycle but can be reached through repeated... https://www.jove.com/v/17183 84 2025-10-03T14:00:28+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17255/17255_article_thumb_17255.jpg Oral Drug Delivery Systems: Continuous-Release Systems Continuous-release drug delivery systems offer a strategic approach to maintaining therapeutic drug levels over extended periods following oral administration. By modulating the release rate of active pharmaceutical ingredients, these systems minimize fluctuations in plasma concentrations, which enhances clinical efficacy and reduces the need for frequent dosing. Such characteristics make them particularly advantageous in managing chronic diseases where patient adherence and stable drug... https://www.jove.com/v/17255 86 2026-02-12T19:17:09+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17260/17260_article_thumb_17260.jpg Intrauterine Drug Delivery Systems Controlled-release systems for intravaginal and intrauterine drug delivery have been developed primarily for the administration of contraceptive steroid hormones. These delivery routes circumvent first-pass hepatic metabolism, thereby enhancing bioavailability and allowing for reduced systemic dosages compared to oral administration. Such approaches contribute to improved therapeutic efficacy and patient compliance, particularly in long-term contraceptive regimens.Intravaginal Drug Delivery... https://www.jove.com/v/17260 81 2026-02-12T19:17:26+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18477/18477_article_thumb_18477.jpg Peritoneal Dialysis II: Peritoneal Dialysis Systems and Complications Peritoneal dialysis (PD) is a medical process that removes waste products and excess fluid from the body using the peritoneal membrane as a natural filter.Peritoneal Dialysis MethodsSeveral methods can be used for peritoneal dialysis, including Acute Intermittent Peritoneal Dialysis, Continuous Ambulatory Peritoneal Dialysis, and Automated Peritoneal Dialysis, also known as Continuous Cyclic Peritoneal Dialysis.Acute Intermittent Peritoneal Dialysis (AIPD) is used for patients with uremic... https://www.jove.com/v/18477 85 2025-06-19T16:27:11+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54622.jpg A Novel Approach for the Administration of Medications and Fluids in Emergency Scenarios and Settings This study presents a novel device that offers an easy route to quickly provide medications and fluids in patients with limited or difficult IV access. This small-diameter device is placed in the distal third of the rectum, allowing for ongoing medication and fluids administration. https://www.jove.com/v/54622 419 2016-11-09T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59801.jpg A Protocol to Set Up Needle-Free Connector with Positive Displacement on Central Venous Catheter in Intensive Care Unit We present a protocol to show the installation of a needle-free connector with positive displacement on a central venous catheter. https://www.jove.com/v/59801 597 2019-07-13T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64831.jpg Enema of Traditional Chinese Medicine for Patients with Severe Acute Pancreatitis An enema is a type of traditional Chinese medicine (TCM) therapy used to treat severe acute pancreatitis (SAP). The therapy involves instilling a TCM liquid into the rectum and colon through the anus to keep the liquid in the intestine, absorbing through the intestinal mucosa. This study aims to standardize the enema procedure for SAP patients. https://www.jove.com/v/64831 365 2023-01-27T21:45:00+00:00 JoVE no https://visualize.jove.com/15374866-spaan-a-software-program-for-prediction-of-adhesins-and-adhesin-like-proteins-using-neural-networks monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3259.jpg A Protocol for Computer-Based Protein Structure and Function Prediction Guidelines for computer based structural and functional characterization of protein using the I-TASSER pipeline is described. Starting from query protein sequence, 3D models are generated using multiple threading alignments and iterative structural assembly simulations. Functional inferences are thereafter drawn based on matches to proteins with known structure and functions. https://www.jove.com/v/3259 1001 2011-11-03T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66314.jpg Computational Prediction of Amino Acid Preferences of Potentially Multispecific Peptide-Binding Domains Involved in Protein-Protein Interactions We describe a methodology based on sequence diversification to estimate the amino acid preferences of multispecific binding sites in protein-protein interactions (PPIs). In this strategy, thousands of potential peptide ligands are generated and screened in silico, thus overcoming some limitations of available experimental methods. https://www.jove.com/v/66314 410 2024-01-26T22:55:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68003.jpg Application of I TASSER, trRosetta, UCSF Chimera, HADDOCK server, and HEX loria for De Novo and In Silico Design of Proteins Protein design involves the construction of amino acid sequences and the incorporation of specific motifs to create functional variants. This approach is critical for the development of antimicrobial peptides (AMPs) to combat antibiotic-resistant pathogens. This paper presents a procedure for protein construction using various bioinformatics tools. https://www.jove.com/v/68003 308 2025-07-08T20:00:00+00:00 JoVE no https://visualize.jove.com/15384517-self-adaptive-blind-source-separation-based-on-activation-functions-adaptation monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/53406.jpg A Novel Experimental and Analytical Approach to the Multimodal Neural Decoding of Intent During Social Interaction in Freely-behaving Human Infants This protocol presents a novel methodology for the neural decoding of intent from freely-behaving infants during unscripted social interaction with an actor. Neural activity is acquired using non-invasive high-density active scalp electroencephalography (EEG). Kinematic data is collected with inertial measurement units and supplemented with synchronized video recording. https://www.jove.com/v/53406 674 2015-10-04T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54038.jpg Visualizing Visual Adaptation This article describes a novel method for simulating and studying adaptation in the visual system. https://www.jove.com/v/54038 283 2017-04-24T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56808.jpg A Method to Study Adaptation to Left-Right Reversed Audition The present study proposes a protocol to investigate the adaptation to left-right reversed audition achieved only by wearable devices, using neuroimaging, which can be an effective tool for uncovering the adaptability of humans to a novel environment in the auditory domain. https://www.jove.com/v/56808 434 2018-10-29T19:30:00+00:00 JoVE no https://visualize.jove.com/15384546-nonlinear-dynamical-factor-analysis-for-state-change-detection monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/15761/15761_article_thumb_15761.jpg Entropy Changes Accompanying Specific Processes Entropy, a measure of disorder in a system, changes during phase transitions like freezing or boiling. At the transition temperature Ttrs, where two phases are in equilibrium, the phase transition is a reversible process. The entropy change can be calculated from a substance's enthalpy of transition using the equation ΔStrs = ΔtrsH /Ttrs.When a perfect gas expands isothermally from one volume to another, entropy increases logarithmically with volume. Conversely, isothermal compression results... https://www.jove.com/v/15761 81 2026-02-26T21:07:28+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16047.jpg Linear time-invariant Systems A system is linear if it displays the characteristics of homogeneity and additivity, together termed the superposition property. This principle is fundamental in all linear systems. Linear time-invariant (LTI) systems include systems with linear elements and constant parameters. The input-output behavior of an LTI system can be fully defined by its response to an impulsive excitation at its input. Once this impulse response is known, the system's reaction to any other input can be calculated... https://www.jove.com/v/16047 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16099.jpg Linear Approximation in Frequency Domain Linear systems are characterized by two main properties: superposition and homogeneity. Superposition allows the response to multiple inputs to be the sum of the responses to each individual input. Homogeneity ensures that scaling an input by a scalar results in the response being scaled by the same scalar. In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear. https://www.jove.com/v/16099 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16100.jpg State Space Representation The frequency-domain technique, commonly used in analyzing and designing feedback control systems, is effective for linear, time-invariant systems. However, it falls short when dealing with nonlinear, time-varying, and multiple-input multiple-output systems. The time-domain or state-space approach addresses these limitations by utilizing state variables to construct simultaneous, first-order differential equations, known as state equations, for an nth-order system. Consider an RLC circuit, a... https://www.jove.com/v/16100 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16101.jpg Transfer Function to State Space State-space representation is a powerful tool for simulating physical systems on digital computers, necessitating the conversion of the transfer function into state-space form. Consider an nth-order linear differential equation with constant coefficients, like those encountered in an RLC circuit. The state variables are selected as the output and its n−1 derivatives. Differentiating these variables and substituting them back into the original equation produces the state equations. In an RLC... https://www.jove.com/v/16101 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16103.jpg Linear Approximation in Time Domain Nonlinear systems often require sophisticated approaches for accurate modeling and analysis, with state-space representation being particularly effective. This method is especially useful for systems where variables and parameters vary with time or operating conditions, such as in a simple pendulum or a translational mechanical system with nonlinear springs. For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length, the... https://www.jove.com/v/16103 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59387.jpg Single-Molecule Tracking Microscopy - A Tool for Determining the Diffusive States of Cytosolic Molecules 3D single-molecule localization microscopy is utilized to probe the spatial positions and motion trajectories of fluorescently labeled proteins in living bacterial cells. The experimental and data analysis protocol described herein determines the prevalent diffusive behaviors of cytosolic proteins based on pooled single-molecule trajectories. https://www.jove.com/v/59387 620 2019-09-05T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65731.jpg Image Recognition and Parameter Analysis of Concrete Vibration State Based on Support Vector Machine The protocol described in this paper utilizes the directional gradient histogram technique to extract the characteristics of concrete image samples under various vibration states. It employs a support vector machine for machine learning, resulting in an image recognition method with minimal training sample requirements and low computer performance demands. https://www.jove.com/v/65731 507 2024-01-05T21:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68955.jpg Age-dependent Dynamics of Locomotion in Caenorhabditis elegans : A Lyapunov Exponent Analysis This study examines the effect of age on locomotion in C. elegans by measuring the largest Lyapunov exponent (LLE). As they age, C. elegans show an increase and subsequent decline in motor control. Results show a peak LLE at five days, followed by a decline as the worms age. https://www.jove.com/v/68955 404 2025-09-23T21:45:00+00:00 JoVE no https://visualize.jove.com/15385347-blood-glucose-control-during-selective-arterial-stimulation-and-venous-sampling-for-localization-of-focal-hyperinsulinism-lesions-in-anesthetized-children monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2432.jpg Hyperinsulinemic-Euglycemic Clamp in the Conscious Rat The hyperinsulinemic-euglycemic clamp is the "gold standard" for the assessment of insulin action. Insulin is infused at a constant rate stimulating glucose uptake. The amount of exogenous glucose infused to counter this drop is indicative of insulin sensitivity. Here the procedure is performed on a conscious, unrestrained rat. https://www.jove.com/v/2432 672 2011-02-08T01:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/3188.jpg Hyperinsulinemic-euglycemic Clamps in Conscious, Unrestrained Mice The hyperinsulinemic-euglycemic clamp, or insulin clamp, is the gold standard for assessing insulin action in vivo. A method for performing insulin clamps in mice is described. This includes a method for arterial catheterization that permits experiments to be performed in conscious, unrestrained mice with minimal stress. https://www.jove.com/v/3188 670 2011-11-16T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14992.jpg Hormones Regulating Blood Glucose Insulin is released by beta cells of the pancreas when blood glucose levels are high. It facilitates glucose absorption and utilization in insulin-dependent cells with insulin receptors on their plasma membranes. Insulin promotes glucose uptake by increasing the number of glucose transport proteins in the cell membrane, allowing glucose to enter the cell. As a result, glucose utilization and ATP production are enhanced. In addition to accelerating glucose uptake and utilization, insulin has... https://www.jove.com/v/14992 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17292.jpg Glucose Homeostasis: Pancreatic Islets and Insulin Secretion The pancreatic islets comprising only 1%-2% of the volume are highly vascularized and innervated mini-organs. They contain five endocrine cell types, including β cells that secrete insulin, which is synthesized as a single polypeptide chain, preproinsulin, processed to proinsulin, and finally to insulin and C-peptide. This process is complex and regulated, involving the Golgi complex, the endoplasmic reticulum, and the secretory granules of the β cell. Insulin and C-peptide are co-secreted in... https://www.jove.com/v/17292 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17306.jpg Hypoglycemia and Glucagon Without prolonged fasting, healthy individuals maintain blood glucose levels above 3.5 mM due to a well-adapted neuroendocrine counterregulatory system that effectively prevents acute hypoglycemia, a potentially life-threatening condition. The primary clinical scenarios for hypoglycemia encompass diabetes treatment, inappropriate production of endogenous insulin or insulin-like substances by tumors, and the use of glucose-lowering agents in non-diabetic individuals. Notably, hypoglycemia in the... https://www.jove.com/v/17306 75 JoVE no https://cloudfront.jove.com/files/ftp_upload/40905/40905_article_thumb_40905.jpg Hypoglycemia Hypoglycemia is a blood glucose level below 70 mg/dL. It commonly occurs in individuals using insulin or insulin-secreting drugs, but may also arise in non-diabetic conditions. People with type 1 diabetes are at the highest risk because they depend on exogenous insulin. People with type 2 diabetes are also at risk, especially when treated with insulin or medications such as sulfonylureas, which increase insulin release regardless of blood glucose levels. It develops when insulin levels exceed... https://www.jove.com/v/40905 86 2026-05-14T19:52:21+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40906/40906_article_thumb_40906.jpg Hyperglycemia Hyperglycemia is an abnormally high blood glucose level. It is diagnosed by fasting glucose ≥126 mg/dL, 2-hour oral glucose tolerance test (or OGTT) ≥200 mg/dL, random glucose ≥200 mg/dL with symptoms, or HbA1c ≥6.5%. However, HbA1c results may be unreliable in certain conditions, such as anemia or hemoglobinopathies, and the diagnosis should be confirmed unless classic symptoms are present. Postprandial hyperglycemia is typically considered significant when glucose levels exceed 180 mg/dL two... https://www.jove.com/v/40906 89 2026-05-14T19:53:15+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65581.jpg Hyperglycemic Clamp and Hypoglycemic Clamp in Conscious Mice A hyperglycemic clamp is used for measuring insulin release with a maintained higher blood glucose concentration. A hypoglycemic clamp is for measuring glucose production induced by counter-regulatory responses. Both methods use the same surgical procedure. Here, we present a clamp technique to assess systemic glucose metabolism. https://www.jove.com/v/65581 455 2024-01-26T21:10:00+00:00 JoVE no https://visualize.jove.com/15389933-simple-model-of-double-adiabatic-inversion-dai-efficiency monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13687.jpg Adiabatic Processes for an Ideal Gas When an ideal gas is compressed adiabatically, that is, without adding heat, work is done on it, and its temperature increases. In an adiabatic expansion, the gas does work, and its temperature drops. Adiabatic compressions actually occur in the cylinders of a car, where the compressions of the gas-air mixture take place so quickly that there is no time for the mixture to exchange heat with its environment. Nevertheless, because work is done on the mixture during the compression, its... https://www.jove.com/v/13687 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13688.jpg Pressure and Volume in an Adiabatic Process Free expansion of a gas is an adiabatic process. However, there are few differences between free expansion and adiabatic expansion. During free expansion, no work is done, and there is no change in internal energy. But, for an adiabatic expansion, work is done, and there is a change in internal energy. During an adiabatic process, the relation between the pressure and volume is obtained from the condition for the adiabatic process, that is, However, for a free expansion process, this... https://www.jove.com/v/13688 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13689.jpg Work Done in an Adiabatic Process Consider the adiabatic compression of an ideal gas in the cylinder of an automobile diesel engine. The gasoline vapor is injected into the cylinder of an automobile engine when the piston is in its expanded position. The temperature, pressure, and volume of the resulting gas-air mixture are 20 °C, 1.00 x 105 N/m2, and 240 cm3 , respectively. The mixture is then compressed adiabatically to a volume of 40 cm3. Note that, in the actual operation of an automobile engine, the compression is not... https://www.jove.com/v/13689 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13694.jpg The Carnot Cycle Converting work to heat is an irreversible process, and the purpose of a heat engine is to reverse the effect partially. Heat engines aim to increase the efficiency of the reversal, that is, maximize the work retrieved from heat. If the efficiency of a heat engine were 100%, it would imply reversing the process completely without introducing any other effect. Thus, it would violate the second law of thermodynamics. What could be the theoretical limit to the efficiency of a heat engine? The... https://www.jove.com/v/13694 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13695.jpg Efficiency of The Carnot Cycle The hypothetical Carnot cycle consists of an ideal gas subjected to two isothermal and two adiabatic processes. Since the internal energy of an ideal gas depends only on its temperature, which is the same before and after the completion of the Carnot cycle, there is no change in its internal energy. Hence, using the first law of thermodynamics, the total heat exchanged by the ideal gas equals the total work done. Thus, we can quantify the efficiency of the Carnot cycle via the heat exchanged... https://www.jove.com/v/13695 76 JoVE no https://cloudfront.jove.com/files/ftp_upload/15759/15759_article_thumb_15759.png Carnot Cycle and Efficiency The Second Law of Thermodynamics asserts that it's impossible for any heat engine to achieve 100% efficiency. While contemplating the maximum possible efficiency, Nicolas Sadi Carnot conceptualized an ideal heat engine. This engine gets its energy from a high-temperature reservoir. It then performs some work and releases the remaining energy into a low-temperature reservoir.The Carnot cycle, named after Sadi Carnot, is fully reversible. The cycle consists of four distinct stages. In the first... https://www.jove.com/v/15759 86 2026-04-29T21:06:47+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55925.jpg Experimental System of Solar Adsorption Refrigeration with Concentrated Collector With solar energy as the driving force, a novel adsorption refrigeration system has been developed and experimentally investigated. Water vapor and zeolite formed the working pair of the adsorption system. This manuscript describes the setup of the experimental rig, the operation procedure, and the important results. https://www.jove.com/v/55925 438 2017-10-18T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59151.jpg A Rapid Method for Modeling a Variable Cycle Engine Here, we present a protocol to build a component-level mathematical model for a variable cycle engine. https://www.jove.com/v/59151 298 2019-08-13T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65892.jpg Optimization of An Air-Based Heat Management System for Dusty Particulate Matter-Covered Lithium-Ion Battery Packs Here, we present the adaptive simulated annealing method (ASAM) to optimize an approximate quadratic response surface model (QRSM) corresponding to a dusty particulate matter-covered battery heat management system and fulfill the temperature drops back by adjusting the airflow velocities combination of system inlets. https://www.jove.com/v/65892 636 2023-11-03T21:40:00+00:00 JoVE no https://visualize.jove.com/15463689-alphavirus-expression-systems-applications-to-mosquito-vector-studies monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2363.jpg Alphavirus Transducing System: Tools for Visualizing Infection in Mosquito Vectors Methods for using alphavirus transducing systems to express fluorescent reporters in vitro and in adult mosquitoes are described. This technique may be adapted to express any protein of interest in lieu of or in addition to a reporter. https://www.jove.com/v/2363 432 2010-11-25T00:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56121.jpg Use of a Recombinant Mosquito Densovirus As a Gene Delivery Vector for the Functional Analysis of Genes in Mosquito Larvae We report using an artificial intronic small RNA expression strategy to develop a non-defective recombinant Aedes aegypti densovirus (AaeDV) in vivo delivery system. A detailed procedure for the construction, packaging, and quantitative analysis of the rAaeDV vectors as well as for larval infection is described. https://www.jove.com/v/56121 750 2017-10-06T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67732.jpg Genome Editing in the Yellow Fever Mosquito Aedes aegypti using CRISPR-Cas9 Here, we describe a detailed protocol for genome editing through embryonic microinjection in the mosquito A. aegypti using the CRISPR-Cas9 technology. https://www.jove.com/v/67732 407 2025-03-21T20:40:00+00:00 JoVE no https://visualize.jove.com/15471599-what-place-for-dna-microarray-in-inflammatory-diseases monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12014.jpg DNA Microarrays Microarrays are high-throughput and relatively inexpensive assays that can be automated to analyze large quantities of data at a time. They are used in genome-wide studies to compare gene or protein expression under two varied conditions, such as healthy and diseased states. Microarrays consist of glass or silica slides on which probe molecules are covalently attached through surface functionalization. Most commonly, the slides are prepared through the chemisorption of silanes to silica... https://www.jove.com/v/12014 154 JoVE no https://cloudfront.jove.com/files/ftp_upload/41006/41006_article_thumb_41006.jpg Inflammatory Bowel Disease III: Crohn's Disease Crohn’s disease is a chronic, relapsing form of inflammatory bowel disease characterized by segmental, transmural inflammation that can affect any part of the gastrointestinal tract. Its pathogenesis arises from a combination of genetic susceptibility, environmental exposures, epithelial barrier dysfunction, and immune dysregulation. Together, these factors lead to an exaggerated immune response against components of the gut microbiome.Genetic and Environmental InfluencesMultiple genetic... https://www.jove.com/v/41006 85 2026-05-19T18:50:58+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50683.jpg Infinium Assay for Large-scale SNP Genotyping Applications A protocol is described that uses Illumina's Infinium assays to perform large-scale genotyping. These assays can reliably genotype millions of SNPs across hundreds of individual DNA samples in three days. Once generated, these genotypes can be used to check for associations with a variety of different diseases or phenotypes. https://www.jove.com/v/50683 813 2013-11-19T22:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51893.jpg A Next-generation Tissue Microarray (ngTMA) Protocol for Biomarker Studies The protocol aims at optimizing the construction and quality of tissue microarrays for biomarker research. It includes aspects of planning and design, digital pathology, virtual slide annotation, and automated tissue arraying. https://www.jove.com/v/51893 572 2014-09-23T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60229.jpg A Cryo-pulverization Protocol for Processing Mouse Paws to Evaluate Molecular Pathways of Tissue Inflammation in a Collagen Induced Arthritis Model A cryogenic pulverization method to process murine paws using a liquid nitrogen freezer mill was developed to improve the yield and quality of RNA or protein extracted from the tissues and enable the analysis of molecular profiles associated with inflammatory responses. https://www.jove.com/v/60229 663 2019-10-30T21:00:00+00:00 JoVE no https://visualize.jove.com/15475120-applications-of-artificial-neural-nets-in-clinical-biomechanics monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/52394.jpg A Human-machine-interface Integrating Low-cost Sensors with a Neuromuscular Electrical Stimulation System for Post-stroke Balance Rehabilitation A novel low-cost human-machine interface for interactive post-stroke balance rehabilitation system is presented in this article. The system integrates off-the-shelf low-cost sensors towards volitionally driven electrotherapy paradigm. The proof-of-concept software interface is demonstrated on healthy volunteers. https://www.jove.com/v/52394 666 2016-04-12T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68588.jpg Soft Pneumatic Robot Modulates Graph Theory Metrics of Brain Network for Hand Rehabilitation After Stroke This study explores the effects of a configurable soft pneumatic robot on enhancing whole-brain network topology post-stroke. Graph theory analysis indicates significant improvements in clustering coefficient, path length, and global efficiency. Findings highlight the potential of programmable robotic protocols to modulate neuroplasticity and optimize functional recovery in stroke rehabilitation. https://www.jove.com/v/68588 330 2025-10-10T21:40:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/69798.jpg Deep-Learning Based Multi-Joint Synchronous Tracking for Objective Quantification of Hindlimb Locomotor Kinematics in Rats This protocol establishes a rat hindlimb kinematic evaluation pipeline using a markerless treadmill test with deep learning-driven multi-joint trajectory auto-labeling, which enables reproducible motion quantification. https://www.jove.com/v/69798 412 2026-04-03T19:43:00+00:00 JoVE no https://visualize.jove.com/15484912-providing-qos-through-machine-learning-driven-adaptive-multimedia-applications monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40773/40773_article_thumb_40773_TN.jpg Methods of Medium Optimization Optimizing growth media enhances microbial proliferation and maximizes product yield. Statistical experimental design methodologies provide structured and reproducible approaches, offering progressively higher levels of robustness and efficiency.The One-Factor-at-a-Time (OFAT) MethodThe One-Factor-at-a-Time (OFAT) method involves adjusting a single variable while keeping all others constant. However, it cannot detect interactions between variables, often leading to suboptimal outcomes when... https://www.jove.com/v/40773 88 2026-03-12T20:57:38+00:00 JoVE no https://visualize.jove.com/15568916-on-the-control-of-chaotic-systems-via-symbolic-time-series-analysis monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16046.jpg Classification of Systems-II Continuous-time systems have continuous input and output signals, with time measured continuously. These systems are generally defined by differential or algebraic equations. For instance, in an RC circuit, the relationship between input and output voltage is expressed through a differential equation derived from Ohm's law and the capacitor relation, Discrete-time systems have input and output signals at specific intervals, defined at distinct instants by difference equations. An example is a... https://www.jove.com/v/16046 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16047.jpg Linear time-invariant Systems A system is linear if it displays the characteristics of homogeneity and additivity, together termed the superposition property. This principle is fundamental in all linear systems. Linear time-invariant (LTI) systems include systems with linear elements and constant parameters. The input-output behavior of an LTI system can be fully defined by its response to an impulsive excitation at its input. Once this impulse response is known, the system's reaction to any other input can be calculated... https://www.jove.com/v/16047 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16053.jpg BIBO stability of continuous and discrete -time systems System stability is a fundamental concept in signal processing, often assessed using convolution. For a system to be considered bounded-input bounded-output (BIBO) stable, any bounded input signal must produce a bounded output signal. A bounded input signal is one where the modulus does not exceed a certain constant at any point in time. To determine the BIBO stability, the convolution integral is utilized when a bounded continuous-time input is applied to a Linear Time-Invariant (LTI) system. https://www.jove.com/v/16053 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16100.jpg State Space Representation The frequency-domain technique, commonly used in analyzing and designing feedback control systems, is effective for linear, time-invariant systems. However, it falls short when dealing with nonlinear, time-varying, and multiple-input multiple-output systems. The time-domain or state-space approach addresses these limitations by utilizing state variables to construct simultaneous, first-order differential equations, known as state equations, for an nth-order system. Consider an RLC circuit, a... https://www.jove.com/v/16100 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16110.jpg SFG Algebra In Signal Flow Graph (SFG) algebra, the value a node represents is determined by the sum of all signals entering that node. This summed value is then transmitted through every branch leaving the node, making the SFG a powerful tool for visualizing and analyzing control systems. Each node in an SFG corresponds to a variable, and the interactions between nodes are represented by branches with associated gains. When multiple branches lead into a node, the value at that node is the sum of the... https://www.jove.com/v/16110 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16127.jpg Time-Domain Interpretation of PD Control Proportional-Derivative (PD) control is a widely used control method in various engineering systems to enhance stability and performance. In a system with only proportional control, common issues include high maximum overshoot and oscillation, observed in both the error signal and its rate of change. This behavior can be divided into three distinct phases: initial overshoot, subsequent undershoot, and gradual stabilization. Consider the example of control of motor torque. Initially, a positive... https://www.jove.com/v/16127 67 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61092.jpg WheelCon: A Wheel Control-Based Gaming Platform for Studying Human Sensorimotor Control WheelCon is a novel, free and open-source platform to design video games that noninvasively simulates mountain biking down a steep, twisting, bumpy trail. It contains components presenting in human sensorimotor control (delay, quantization, noise, disturbance, and multiple feedback loops) and allows researchers to study the layered architecture in sensorimotor control. https://www.jove.com/v/61092 498 2020-08-15T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61943.jpg Real-Time Proxy-Control of Re-Parameterized Peripheral Signals using a Close-Loop Interface We present protocols and methods of analyses to build co-adaptive interfaces that stream, parameterize, analyze, and modify human body and heart signals in close-loop. This setup interfaces signals derived from the peripheral and central nervous systems of the person with external sensory inputs to help track biophysical change. https://www.jove.com/v/61943 714 2021-05-08T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68955.jpg Age-dependent Dynamics of Locomotion in Caenorhabditis elegans : A Lyapunov Exponent Analysis This study examines the effect of age on locomotion in C. elegans by measuring the largest Lyapunov exponent (LLE). As they age, C. elegans show an increase and subsequent decline in motor control. Results show a peak LLE at five days, followed by a decline as the worms age. https://www.jove.com/v/68955 404 2025-09-23T21:45:00+00:00 JoVE no https://visualize.jove.com/15574841-dna-interference-a-simple-and-efficient-gene-silencing-system-for-high-throughput-functional-analysis-in-the-fern-adiantum monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2477.jpg RNAi Interference by dsRNA Injection into Drosophila Embryos RNA interference has been proven very effective to analyze gene function in Drosophila tracheal development. A detailed protocol used by Jiang lab to inject dsRNA into fly embryos to knockdown gene expression is illustrated. This technique has the potential for screening genes required for tissue and organ development in Drosophila. https://www.jove.com/v/2477 510 2011-04-11T18:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/3448.jpg Quantitative and Automated High-throughput Genome-wide RNAi Screens in C. elegans We describe a protocol using C. elegans and RNAi feeding libraries that allows automated measurement of multiple parameters such as fluorescence, size and opacity of individual worms in a population. We give one example of a screen to identify genes involved in anti-fungal innate immunity in C. elegans. https://www.jove.com/v/3448 658 2012-02-27T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10804.jpg RNA Interference RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated. This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used... https://www.jove.com/v/10804 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10813.jpg In-vitro Mutagenesis To learn more about the function of a gene, researchers can observe what happens when the gene is inactivated or “knocked out,” by creating genetically engineered knockout animals. Knockout mice have been particularly useful as models for human diseases such as cancer, Parkinson’s disease, and diabetes. The Process Genes can be randomly knocked out, or specific genes can be targeted. To knock out a particular gene, an engineered piece of DNA called a targeting vector is used to replace the... https://www.jove.com/v/10813 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11629.jpg siRNA - Small Interfering RNAs Small interfering RNAs, or siRNAs, are short regulatory RNA molecules that can silence genes post-transcriptionally, as well as the transcriptional level in some cases. siRNAs are important for protecting cells against viral infections and silencing transposable genetic elements. In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the ATP-dependent... https://www.jove.com/v/11629 150 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12033.jpg Experimental RNAi RNA interference (RNAi) is a cellular mechanism that inhibits gene expression by suppressing its transcription or activating the RNA degradation process. The mechanism was discovered by Andrew Fire and Craig Mello in 1998 in plants. Today, it is observed in almost all eukaryotes, including protozoa, flies, nematodes, insects, parasites, and mammals. This precise cellular mechanism of gene silencing has been developed into a technique that provides an efficient way to identify and determine the... https://www.jove.com/v/12033 135 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54976.jpg Rearing and Double-stranded RNA-mediated Gene Knockdown in the Hide Beetle, Dermestes maculatus Here, we present protocols for rearing an intermediate-germ beetle, Dermestes maculatus (D. maculatus) in the lab. We also share protocols for embryonic and parental RNAi and methods for analyzing embryonic phenotypes to study gene function in this species. https://www.jove.com/v/54976 597 2016-12-28T21:00:00+00:00 JoVE no https://visualize.jove.com/15598283-the-early-history-of-ivf-in-australia-and-its-contribution-to-the-world-1970-1990 monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10907.jpg Fertilization During fertilization, an egg and sperm cell fuse to create a new diploid structure. In humans, the process occurs once the egg has been released from the ovary, and travels into the fallopian tubes. The process requires several key steps: 1) sperm present in the genital tract must locate the egg; 2) once there, sperm need to release enzymes to help them burrow through the protective zona pellucida of the egg; and 3) the membranes of a single sperm cell and egg must fuse, with the sperm... https://www.jove.com/v/10907 98 2025-10-23T18:49:04+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10816.jpg Reproductive Cloning Reproductive cloning is the process of producing a genetically identical copy—a clone—of an entire organism. While clones can be produced by splitting an early embryo—similar to what happens naturally with identical twins—cloning of adult animals is usually done by a process called somatic cell nuclear transfer (SCNT). Somatic Cell Nuclear Transfer In SCNT, an egg cell is taken from an animal and its nucleus is removed, creating an enucleated egg. Then a somatic cell—any cell that is not a sex... https://www.jove.com/v/12031 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13477.jpg Cloning of Dolly the Sheep The first successfully cloned mammal was Dolly, a sheep, born on 5th July 1996 at Roslin Institute, Scotland. The cloned sheep was named after the American singer Dolly Parton. Dolly lived for seven years and died of respiratory complications, which is speculated to be due to the actual age of her DNA. Because the DNA in cloned cells belongs to an older individual, the cloned individual’s life expectancy may be affected. Indeed, analysis of Dolly’s DNA revealed shorter telomeres than other... https://www.jove.com/v/13477 68 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16314.jpg In Vitro Fertilization In vitro fertilization (IVF) is a form of assisted reproductive technology where an egg is fertilized with sperm in a controlled laboratory environment before transferring the resulting embryo into the uterus. This process is designed to help individuals and couples experiencing difficulties conceiving. The IVF process begins with ovarian stimulation, during which reproductive endocrinologists prescribe hormonal medications to stimulate the ovaries to produce multiple eggs instead of the single... https://www.jove.com/v/16314 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16317.jpg Infertility in Males Male infertility affects millions of couples worldwide, arising from various factors that impact different stages of the reproductive process. An endocrine imbalance resulting from conditions like hypogonadism, Klinefelter syndrome, or pituitary disorders can disrupt hormone levels and reduce sperm production. Testicular defects, such as tumors, cryptorchidism, atrophic testes, abnormal sperm morphology, and low sperm count or motility, may arise due to genetic factors, structural... https://www.jove.com/v/16317 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16318.jpg Infertility in Females Female infertility is defined as the inability to conceive after a year of regular, unprotected intercourse and affects about 10–15% of couples worldwide. The primary cause of female infertility is ovulatory disorders, which hinder the release of eggs. These disorders can be classified as hypothalamic amenorrhea, polycystic ovarian syndrome (PCOS), premature ovarian failure, and hyperprolactinemic anovulation disorders. Endometriosis, a condition characterized by abnormal growth of endometrial... https://www.jove.com/v/16318 88 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61647.jpg OP-IVM: Combining In vitro Maturation after Oocyte Retrieval with Gynecological Surgery In vitro maturation (IVM) before gynecological operation (OP-IVM) combines IVM following oocyte retrieval with routine gynecological surgery and serves as an extension of conventional IVM applications for fertility preservation. https://www.jove.com/v/61647 331 2021-05-09T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61963.jpg Fertility Preservation Through Oocyte Vitrification: Clinical and Laboratory Perspectives Oocyte cryopreservation is recognized by several international scientific societies as the gold standard for fertility preservation in postpubertal women. Appropriate clinical and laboratory strategies ensure maximum efficacy, efficiency, and safety of fertility preservation treatments. https://www.jove.com/v/61963 526 2021-09-16T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/69122.jpg Collection of Human Follicular Fluid, Follicle Somatic Cells, and Immature Oocytes from Individuals Undergoing In Vitro Fertilization This protocol outlines standardized methods to isolate and process follicular fluid, somatic cells, and immature oocytes from IVF procedures, enabling high-quality molecular and cellular analyses. These approaches support translational research into fertility, reproductive aging, and ovarian dysfunction using materials typically discarded in clinical care. https://www.jove.com/v/69122 400 2025-10-24T21:10:00+00:00 JoVE no https://visualize.jove.com/15608051-an-architecture-for-biological-information-extraction-and-representation monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1869.jpg Hi-C: A Method to Study the Three-dimensional Architecture of Genomes. The Hi-C method allows unbiased, genome-wide identification of chromatin interactions (1). Hi-C couples proximity ligation and massively parallel sequencing. The resulting data can be used to study genomic architecture at multiple scales: initial results identified features such as chromosome territories, segregation of open and closed chromatin, and chromatin structure at the megabase scale. https://www.jove.com/v/1869 1347 2010-05-07T00:00:00+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/11014/11014_article_thumb_11014.jpg Phylogenetic Trees Phylogenetic trees come in many forms. It matters in which sequence the organisms are arranged from the bottom to the top of the tree, but the branches can rotate at their nodes without altering the information. The lines connecting individual nodes can be straight, angled, or even curved.The length of the branches can depict time or the relative amount of change among organisms. For instance, the branch length might indicate the number of amino acid changes in the sequence that underlies the... https://www.jove.com/v/11014 201 2026-06-01T13:28:25+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11987.jpg Evolutionary Relationships through Genome Comparisons Genome comparison is one of the excellent ways to interpret the evolutionary relationships between organisms. The basic principle of genome comparison is that if two species share a common feature, it is likely encoded by the DNA sequence conserved between both species. The advent of genome sequencing technologies in the late 20th century enabled scientists to understand the concept of conservation of domains between species and helped them to deduce evolutionary relationships across diverse... https://www.jove.com/v/11987 174 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12023.jpg Genome Annotation and Assembly The genome refers to all of the genetic material in an organism. It can range from a few million base pairs in microbial cells to several billion base pairs in many eukaryotic organisms. Genome assembly refers to the process of taking the DNA sequencing data and putting it all back together in a correct order to create a close representation of the original genome. This is followed by the identification of functional elements on the newly assembled genome, a process called genome annotation.<br... https://www.jove.com/v/12023 216 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12037.jpg Synthetic Biology Synthetic biology is an interdisciplinary science that involves using principles from disciplines such as engineering, molecular biology, cell biology, and systems biology. It involves remodeling existing organisms from nature or constructing completely new synthetic organisms for applications such as protein or enzyme production, bioremediation, value-added macromolecule production, and the addition of desirable traits to crops, to name a few. Golden rice Golden rice is a genetically modified... https://www.jove.com/v/12037 175 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13389.jpg Imaging Biological Samples with Optical Microscopy Optical microscopy uses optic principles to provide detailed images of samples. Antonie van Leeuwenhoek designed the first compound optical microscope in the 17th century to visualize blood cells, bacteria, and yeast cells. In 1830, Joseph Jackson Lister created an essentially modern light microscope. The 20th century saw the development of microscopes with enhanced magnification and resolution. In optical microscopy, the specimen to be viewed is placed on a glass slide and clipped on the stage... https://www.jove.com/v/13389 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13848.jpg Structural Organization of the Human Body: An Overview It is convenient to consider the body's structures in terms of fundamental levels of organization that increase in complexity: subatomic particles, atoms, molecules, organelles, cells, tissues, organs, organ systems, and organisms. To study the chemical level of organization, scientists consider the simplest building blocks of matter: subatomic particles, atoms, and molecules. All matter in the universe is composed of one or more unique pure substances called elements, familiar examples of... https://www.jove.com/v/13848 78 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54869.jpg A Web Tool for Generating High Quality Machine-readable Biological Pathways PathWhiz is a comprehensive, online pathway drawing tool for generating biochemical and biological pathways. It uses publicly accessible databases and easily expandable palettes consisting of pre-drawn pathway components. This protocol describes how to easily build new pathways, replicate and edit existing pathways, and propagate previously drawn pathways to different organisms. https://www.jove.com/v/54869 481 2017-02-08T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60038.jpg Databases to Efficiently Manage Medium Sized, Low Velocity, Multidimensional Data in Tissue Engineering Many researchers generate "medium-sized", low-velocity, and multi-dimensional data, which can be managed more efficiently with databases rather than spreadsheets. Here we provide a conceptual overview of databases including visualizing multi-dimensional data, linking tables in relational database structures, mapping semi-automated data pipelines, and using the database to elucidate data meaning. https://www.jove.com/v/60038 583 2019-11-22T20:00:00+00:00 JoVE no https://visualize.jove.com/15615746-routine-monitoring-of-visual-outcome-of-cataract-surgery-part-2-results-from-eight-study-centres monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/60673.jpg Assessing Early Stage Open-Angle Glaucoma in Patients by Isolated-Check Visual Evoked Potential The isolated-check visual evoked potential (icVEP) method is implemented here to assess the magnocellular ON pathway that is initially damaged in glaucoma. The study shows standard operative procedures using icVEP to obtain reliable results. It is proved to serve as a useful objective diagnosing technology for the early detection of glaucoma. https://www.jove.com/v/60673 431 2020-05-25T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65419.jpg Rotating the Intraocular Lens to Prevent Posterior Capsular Opacification in Cataract Surgeries The present protocol describes removing residual epithelial cells by rotating the intraocular lens in extracapsular cataract surgery without extra tools for preventing posterior capsular opacification. https://www.jove.com/v/65419 299 2023-07-07T21:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/69593.jpg Implantation Protocol of the Foldable Capsular Vitreous Body for Complex Vitreoretinal Surgery The Foldable Capsular Vitreous Body (FCVB) is an intraocular implant that encapsulates silicone oil within a flexible capsule to reduce silicone oil-related complications. This protocol describes the surgical implantation of the FCVB via scleral incision for the treatment of complex retinal detachment and ocular trauma. https://www.jove.com/v/69593 276 2026-04-14T20:35:00+00:00 JoVE no https://visualize.jove.com/15617960-basic-research-and-12-years-of-clinical-experience-in-computer-assisted-navigation-technology-a-review monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/63400.jpg Dynamic Navigation for Dental Implant Placement Dynamic computer-aided implant surgery (DCAIS) is a controlled implant surgical placement method performed without a surgical template using optical control. The real-time intraoperative control of movement and position of the surgical device simplifies the procedure and gives more freedom to the surgeon, providing similar precision as static navigation methods. https://www.jove.com/v/63400 342 2022-09-13T19:40:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63687.jpg Dynamic Navigation in Endodontics: Guided Access Cavity Preparation by Means of a Miniaturized Navigation System Dynamic navigation systems (DNS) provide real-time visualization and guidance to the operator during endodontic access cavities preparation. The planning of the procedure requires three-dimensional imaging utilizing cone beam computed tomography and surface scans. After the export of the planning data to the DNS, access cavities can be prepared with minimal invasion. https://www.jove.com/v/63687 423 2022-05-05T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68607.jpg Technical Approach for Infrared Tracking for Soft Tissue Navigation with a Holographic Head-Mounted Display and Preclinical Validation This protocol offers a guide to implement infrared marker tracking for free-moving phantoms (e.g., organs) and holographic visualization using Augmented Reality. Additionally, it outlines a setup for preclinical validation of holographic navigation systems using electromagnetic tracking on free-moving phantoms. https://www.jove.com/v/68607 625 2025-09-02T21:15:00+00:00 JoVE no https://visualize.jove.com/15630481-construction-of-a-bacterial-autoinducer-detection-system-in-mammalian-cells monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10713.jpg Bacterial Signaling Bacterial signaling can occur within bacteria (intracellular) or between bacteria (intercellular). At times, a group of bacteria behaves like a community. To achieve this, they engage in quorum sensing, the perception of higher cell density that causes changes in gene expression. Quorum sensing involves both extracellular and intracellular signaling. The signaling cascade starts with a molecule called an autoinducer (AI). Individual bacteria produce AIs that move out of the bacterial cell... https://www.jove.com/v/10713 90 JoVE no https://cloudfront.jove.com/files/ftp_upload/19539/19539_article_thumb_19539.jpg Gene Regulation in Microbial Communities: Quorum Sensing Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,... https://www.jove.com/v/19539 88 2025-06-12T16:15:28+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50863.jpg Using Coculture to Detect Chemically Mediated Interspecies Interactions Bacteria produce secreted compounds that have the potential to affect the physiology of their microbial neighbors. Here we describe a coculture screen that allows detection of such chemically mediated interspecies interactions by mixing soil microbes with fluorescent transcriptional reporter strains of Bacillus subtilis on solid media. https://www.jove.com/v/50863 509 2013-11-01T02:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52903.jpg Applying an Inducible Expression System to Study Interference of Bacterial Virulence Factors with Intracellular Signaling The method described here is used to induce the apoptotic signaling cascade at defined steps in order to dissect the activity of an anti-apoptotic bacterial effector protein. This method can also be used for inducible expression of pro-apoptotic or toxic proteins, or for dissecting interference with other signaling pathways. https://www.jove.com/v/52903 531 2015-06-25T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55300.jpg Using Synthetic Biology to Engineer Living Cells That Interface with Programmable Materials This paper presents a series of protocols for developing engineered cells and functionalized surfaces that enable synthetically engineered E. coli to control and manipulate programmable material surfaces. https://www.jove.com/v/55300 628 2017-03-09T23:00:00+00:00 JoVE no https://visualize.jove.com/15648079-interactive-measurement-and-characterization-of-dna-molecules-by-analysis-of-afm-images monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3061.jpg Visualization of Recombinant DNA and Protein Complexes Using Atomic Force Microscopy A tapping mode atomic force microscope (AFM) method for the visualization of plasmid DNA, cytoplasmic proteins, and DNA-protein complexes is described. The method includes alternate approaches for preparing samples for AFM imaging following biochemical manipulation. DNA containing specific protein interacting regions are observed in near-physiologic buffer conditions. https://www.jove.com/v/3061 510 2011-07-18T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13397.jpg Atomic Force Microscopy Atomic force microscopy (AFM) is a type of scanning probe microscopy that can analyze topographic details of various specimens like ceramics, glass, polymers, and biological samples. AFM offers over 1000 times more resolution than the optical imaging system. Images generated from AFM are three-dimensional surface profiles, offering an advantage over the flat, two-dimensional images from other imaging techniques. The AFM Probe The probe is regarded as the heart of any AFM setup and comprises the... https://www.jove.com/v/13397 68 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55501.jpg Atomic Force Microscopy Investigations of DNA Lesion Recognition in Nucleotide Excision Repair Here, the study of different DNA lesion recognition approaches via single molecule AFM imaging is demonstrated with the nucleotide excision repair system as an example. The procedures of DNA and protein sample preparations and experimental as well as analytical details for the AFM experiments are described. https://www.jove.com/v/55501 659 2017-05-24T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66470.jpg High-Speed Atomic Force Microscopy Imaging of DNA Three-Point-Star Motif Self Assembly Using Photothermal Off-Resonance Tapping Here, we show the imaging protocol for observing biomolecular interactions with photothermal off-resonance tapping (PORT), where we optimized imaging parameters, identified system limits, and investigated potential improvements in imaging three-point-star DNA motif assembly. https://www.jove.com/v/66470 539 2024-03-22T21:00:00+00:00 JoVE no https://visualize.jove.com/15684549-proposal-for-a-framework-for-optimizing-artificial-environments-based-on-physiological-feedback monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2320.jpg Combining Computer Game-Based Behavioural Experiments With High-Density EEG and Infrared Gaze Tracking Procedures for recording high-density EEG and gaze data during computer game-based cognitive tasks are described. Using a video game to present cognitive tasks enhances ecological validity without sacrificing experimental control. https://www.jove.com/v/2320 820 2010-12-17T01:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12140.jpg Positive and Negative Feedback Loops Animal organs and organ systems constantly adjust to internal and external changes through a process called homeostasis ("steady state"). Examples of these changes include regulation of the level of glucose or calcium in the blood or internal responses to external temperatures. Homeostasis requires maintaining an internal dynamic equilibrium: Dynamic because it constantly adjusts to the changes that the body's systems encounter. Equilibrium because body functions are kept within specific... https://www.jove.com/v/12140 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13831.jpg Physiological Control of Respiration Introduction Breathing, a seemingly passive process, is regulated by the respiratory center in the brainstem. This center coordinates the involuntary control of respirations, which means it occurs without conscious effort, ensuring a smooth and uninterrupted pattern. Regulation of Ventilation The body maintains ventilation by monitoring levels of carbon dioxide (CO2), oxygen (O2), and hydrogen ion concentration (pH) in the arterial blood. Among these factors, the level of CO2 plays a crucial... https://www.jove.com/v/13831 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15008.jpg Physiological Barriers Physiological barriers are semi-permeable cellular structures restricting drug diffusion into intracellular compartments and tissues. There are six types of physiological barriers: blood endothelial, cell membrane, blood-brain, blood-cerebrospinal fluid (CSF), blood-placenta, and blood-testis barriers. The blood endothelial barrier is the most porous of these. It allows all small ionized, un-ionized, and lipophilic molecules to pass through the endothelial lining into the interstitial space... https://www.jove.com/v/15008 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16555.jpg Clearance Models: Physiological Models Drug clearance is a critical pharmacokinetic process involving the irreversible removal of drugs from the body through various organs over a specified time period. Physiological models are indispensable in determining organ-specific clearance, defined by the proportion of the drug eliminated per unit of time from the organ's blood volume. The organ's clearance rate depends on the blood flow to the organ and the extraction ratio (E). The extraction ratio describes the organ's proficiency in drug... https://www.jove.com/v/16555 69 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16587.jpg Model Approaches for Pharmacokinetic Data: Physiological Models Physiological models in pharmacokinetics are instrumental in understanding the distribution and elimination of drugs within the body. These models describe the drug concentration within target organs, influenced by factors such as drug uptake, tissue volume, and blood flow. Drug uptake is governed by the partition coefficient, which signifies the drug concentration ratio in tissue to that in the blood. The blood flow rate to a specific tissue is expressed as Qt, and the rate of change in tissue... https://www.jove.com/v/16587 75 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58318.jpg Virtual Reality Experiments with Physiological Measures Virtual reality (VR) experiments can be difficult to implement and require meticulous planning. This protocol describes a method for the design and implementation of VR experiments that collect physiological data from human participants. The Experiments in Virtual Environments (EVE) framework is employed to accelerate this process. https://www.jove.com/v/58318 429 2018-08-29T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61943.jpg Real-Time Proxy-Control of Re-Parameterized Peripheral Signals using a Close-Loop Interface We present protocols and methods of analyses to build co-adaptive interfaces that stream, parameterize, analyze, and modify human body and heart signals in close-loop. This setup interfaces signals derived from the peripheral and central nervous systems of the person with external sensory inputs to help track biophysical change. https://www.jove.com/v/61943 714 2021-05-08T21:30:00+00:00 JoVE no https://visualize.jove.com/15686968-human-apoe4-targeted-replacement-mice-display-synaptic-deficits-in-the-absence-of-neuropathology monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/53308.jpg Intracerebroventricular Injection of Amyloid-β Peptides in Normal Mice to Acutely Induce Alzheimer-like Cognitive Deficits The amyloid-β (Aβ)-injected animal model enables the administration of a defined quantity and species of Aβ fragments and reduces individual differences within each study group. This protocol describes the intracerebroventricular (ICV) injection of Aβ without stereotactic instruments, enabling the production of Alzheimer-like behavioral abnormalities in normal mice. https://www.jove.com/v/53308 481 2016-03-16T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54136.jpg A Phenotyping Regimen for Genetically Modified Mice Used to Study Genes Implicated in Human Diseases of Aging A reverse-genetics approach to understanding gene families associated with human disease is presented, using mouse as a model system, and the subsequent mouse phenotyping schedule is described. Because mice defective in a gene of interest, HtrA2, manifested Parkinsonian symptoms, the phenotyping regimen is focused on identifying neurological defects. https://www.jove.com/v/54136 577 2016-07-14T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55523.jpg Assessment of Spontaneous Alternation, Novel Object Recognition and Limb Clasping in Transgenic Mouse Models of Amyloid-β and Tau Neuropathology Described here is a staged, behavioral screening approach that can be used to screen for compounds that exhibit in vivo efficacy on cognitive and functional motor behaviors in transgenic mouse models of β-amyloidosis and tauopathy. These methods are optimized to screen compounds for activity in short-term and working memory tasks. https://www.jove.com/v/55523 602 2017-05-28T20:00:00+00:00 JoVE no https://visualize.jove.com/15713630-fine-structure-analysis-of-activation-induced-deaminase-accessibility-to-class-switch-region-r-loops monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11512.jpg Conserved Binding Sites Many proteins’ biological role depends on their interactions with their ligands, small molecules that bind to specific locations on the protein known as ligand-binding sites. Ligand-binding sites are often conserved among homologous proteins as these sites are critical for protein function. Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally analyses the... https://www.jove.com/v/11512 109 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11516.jpg Ligand Binding and Linkage Allosteric proteins have more than one ligand binding site; the binding of a ligand to any of these sites influences the binding of ligands to the other sites. When a protein is allosteric, its binding sites are called coupled or linked. In the case of enzymes, the site that binds to the substrate is known as the active site and the other site is known as the regulatory site. When a ligand binds to the regulatory site, this leads to conformational changes in the protein that can influence the... https://www.jove.com/v/11516 49 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11521.jpg Covalently Linked Protein Regulators Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified. These groups modify specific amino acids in a protein. https://www.jove.com/v/11521 124 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12221.jpg Allosteric Proteins-ATCase Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor. Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,... https://www.jove.com/v/12221 79 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59700.jpg DNAzyme-dependent Analysis of rRNA 2’-O-Methylation Here we present a protocol for DNAzyme-dependent cleavage of RNA. This enables fast and site-dependent analysis of RNA 2’-O-methylation. This approach can be used for the preliminary or major assessment of snoRNA activity. https://www.jove.com/v/59700 552 2019-09-16T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61125.jpg Deciphering the Structural Effects of Activating EGFR Somatic Mutations with Molecular Dynamics Simulation The objective of this protocol is to use molecular dynamics simulations to examine the dynamic structural changes that occur due to activating mutations of the EGFR kinase protein. https://www.jove.com/v/61125 905 2020-05-20T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63147.jpg CD Spectroscopy to Study DNA-Protein Interactions The interaction of an ATP-dependent chromatin remodeler with a DNA ligand is described using CD spectroscopy. The induced conformational changes on a gene promoter analyzed by the peaks generated can be used to understand the mechanism of transcriptional regulation. https://www.jove.com/v/63147 408 2022-02-10T22:00:00+00:00 JoVE no https://visualize.jove.com/15722445-insights-into-the-domains-required-for-dimerization-and-assembly-of-human-alphab-crystallin monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10679.jpg Protein Folding Overview Proteins are chains of amino acids linked together by peptide bonds. Upon synthesis, a protein folds into a three-dimensional conformation which is critical to its biological function. Interactions between its constituent amino acids guide protein folding, and hence the protein structure is primarily dependent on its amino acid sequence. Protein Structure Is Critical to Its Biological Function Proteins perform a wide range of biological functions such as catalyzing chemical... https://www.jove.com/v/10679 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11486.jpg Gene Families Gene families consist of groups of genes proposed to have originated from a common ancestor. Typically these arise through events in which a gene or genes are mistakenly duplicated during cell division. Unlike their parent genes (which are subject to selection pressure to maintain function), these gene copies do not need to preserve their sequences and may evolve at a relatively faster rate. Occasionally these regions can be adapted to take on new roles within the organism, becoming novel genes... https://www.jove.com/v/11486 117 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11503.jpg Conservation of Protein Domains Over Different Proteins Protein domains are small structurally independent units that are part of a single amino acid chain. Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms. A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form... https://www.jove.com/v/11503 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11506.jpg Protein Complex Assembly Proteins can form homomeric complexes with another unit of the same protein or heteromeric complexes with different types. Most protein complexes self-assemble spontaneously via ordered pathways, while some proteins need assembly factors that guide their proper assembly. Despite the crowded intracellular environment, proteins usually interact with their correct partners and form functional complexes. Many viruses self-assemble into a fully functional unit using the infected host cell to... https://www.jove.com/v/11506 161 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11512.jpg Conserved Binding Sites Many proteins’ biological role depends on their interactions with their ligands, small molecules that bind to specific locations on the protein known as ligand-binding sites. Ligand-binding sites are often conserved among homologous proteins as these sites are critical for protein function. Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally analyses the... https://www.jove.com/v/11512 109 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13159.jpg Assembly of Signaling Complexes Multiprotein signaling complexes are formed in a dynamic process involving protein-protein interactions at the cytoplasmic domain of transmembrane receptors or enzymatic and non-enzymatic proteins associated with the receptor. These complexes ensure the activation and propagation of intracellular signals that regulate cell functions. Interaction domains in cell signaling Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,... https://www.jove.com/v/13159 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54886.jpg Combining Wet and Dry Lab Techniques to Guide the Crystallization of Large Coiled-coil Containing Proteins We describe a framework incorporating straightforward biochemical and computational analysis to guide the characterization and crystallization of large coiled-coil domains. This framework can be adapted for globular proteins or extended to incorporate a variety of high-throughput techniques. https://www.jove.com/v/54886 674 2017-01-06T18:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56091.jpg A Guide to Production, Crystallization, and Structure Determination of Human IKK1/α IκB Kinase 1/α (IKK1/α CHUK) is a Ser/Thr protein kinase that is involved in a myriad of cellular activities primarily through activation of NF-κB transcription factors. Here, we describe the main steps necessary for the production and crystal structure determination of this protein. https://www.jove.com/v/56091 687 2018-11-02T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65828.jpg ABCG5/G8 Crystallization in a Lipidic Bicelle Environment for X-Ray Crystallography This protocol describes a setup for the crystallization of the sterol transporter ABCG5/G8. ABCG5/G8 is reconstituted into bicelles for hanging-drop crystallization. The protocol does not require specialized materials or substrates, making it accessible and easy to adapt in any laboratory for determining the protein structure through X-ray crystallography. https://www.jove.com/v/65828 407 2023-08-25T21:40:00+00:00 JoVE no https://visualize.jove.com/15803107-reproducibility-and-variability-in-the-action-of-injected-insulin monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2722.jpg Insulin Injection and Hemolymph Extraction to Measure Insulin Sensitivity in Adult Drosophila melanogaster Conserved insulin signaling pathways found in the fruit fly Drosophila melanogaster make this organism a potential tool for modeling metabolic disorders including type II diabetes. To this end, it is critical to establish physiological assays to effectively measure systemic insulin action in peripheral glucose disposal in the adult fly. https://www.jove.com/v/2722 352 2011-06-30T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/3705.jpg Improving IV Insulin Administration in a Community Hospital When compared to the previous paper protocol, implementation of a computerized glucose management system results in a substantial increase in blood glucose concentration measurements within the target range. Using a computerized glucose management system to monitor blood glucose levels, decreases in severe hypoglycemia (<40 mg/dL), clinical hypoglycemia (<70 mg/dL), and hyperglycemia (>180 mg/dL) also can be observed. https://www.jove.com/v/3705 728 2012-06-11T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16478.jpg Variability: Analysis Measures of variability are statistical metrics that reveal the dispersion pattern within a dataset. They are pivotal in biostatistics, providing insights into the heterogeneity within health and biological data. Variability signifies the degree to which data points diverge from one another, helping researchers understand the potential range of values and associated uncertainty within the data. The range is a simple measure of variability, indicating the difference between the highest and... https://www.jove.com/v/16478 71 JoVE no https://cloudfront.jove.com/files/ftp_upload/17178/17178_article_thumb_17178.jpg Dosage Regimen: Individualization Individualization in dosing regimens is the customization of medication doses for individual patients. Its necessity arises from the goal of maximizing therapeutic benefits while minimizing risks. This approach is pivotal because human responses to drugs can vary widely; what is effective for one person may be inadequate or excessive for another. Interpatient (intersubject) variability refers to differences in drug responses between individuals, while intrapatient (intrasubject) variability... https://www.jove.com/v/17178 84 2025-10-03T14:00:29+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17297.jpg Insulin: Biosynthesis, Chemistry, and Preparation The endoplasmic reticulum (ER) of pancreatic β-cells synthesizes preproinsulin, which consists of a signal peptide, A and B chains, and a C-peptide. Preproinsulin is then cleaved and folded into proinsulin, which translocates to the Golgi apparatus for sorting and packaging into secretory granules. In these granules, enzymatic clipping generates insulin and C-peptide. Damage or functional impairment of β-cells inhibits insulin production, leading to diabetes. Diabetes treatment primarily uses... https://www.jove.com/v/17297 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17298.jpg Insulin Formulations: Types and Delivery Insulin preparations are categorized by their duration of action into short-acting and long-acting types. Two strategies are used to modify insulin's absorption and pharmacokinetic profile: slowing the absorption post-subcutaneous injection, or altering human insulin's amino acid sequence or protein structure. These changes retain the insulin's ability to bind to the insulin receptor, but alter its behavior in solution or after injection. Short-acting insulins are divided into rapid-acting... https://www.jove.com/v/17298 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17299.jpg Insulin: Dosing Regimen and Adverse Effects Insulin-replacement therapy usually includes both long-acting insulin (basal) and short-acting insulin (to cater to postprandial needs). In a diverse group of type 1 diabetes patients, the average daily insulin dose is typically 0.5-0.7 units/kg body weight. However, obese patients and pubertal adolescents may need more due to insulin resistance. The basal dose constitutes about 40%-50% of the total daily dose, with the rest as premeal insulin. The mealtime insulin dose should mirror... https://www.jove.com/v/17299 76 JoVE no https://cloudfront.jove.com/files/ftp_upload/40781/40781_article_thumb_40781.jpeg Production of Pharmaceuticals Industrial insulin production uses genetically engineered E. coli expressing a proinsulin gene controlled by a tryptophan promoter and containing a methionine linker for later cleavage. The cells also carry ampicillin resistance for selective growth. Seed cultures are stored at −80 °C and production begins by thawing a small amount to inoculate starter cultures, which are progressively scaled to a 50,000-L bioreactor. In the bioreactor, E. coli grow in nutrient-rich media under sterile, tightly... https://www.jove.com/v/40781 90 2026-03-12T20:36:06+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57531.jpg Homogeneous Time-resolved Förster Resonance Energy Transfer-based Assay for Detection of Insulin Secretion Here, we present homogeneous time resolved FRET (HTRF) as an efficient method for rapid detection of insulin secreted from cells. https://www.jove.com/v/57531 450 2018-05-10T21:00:00+00:00 JoVE no https://visualize.jove.com/15838142-an-index-structure-for-pattern-similarity-searching-in-dna-microarray-data monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2663.jpg Genomic MRI - a Public Resource for Studying Sequence Patterns within Genomic DNA We present a public computational web site for the analysis of genomic sequences. It detects DNA sequence patterns with various non-random nucleotide compositions. This resource also generates randomized sequences with diverse levels of complexity. https://www.jove.com/v/2663 756 2011-05-09T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/10787/10787_article_thumb_10787.jpg Karyotyping Describing the number and physical features of chromosomes can reveal abnormalities that underlie genetic diseases. This description is facilitated by special staining techniques that produce a particular banding pattern on each chromosome. State-of-the-art techniques make this approach even more powerful, enabling the detection of individual genes that cause disease.A Simple Chromosome Staining Technique Provides Valuable Scientific InsightSome genetic diseases can be detected by looking at... https://www.jove.com/v/10787 77 2026-06-01T13:28:21+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12014.jpg DNA Microarrays Microarrays are high-throughput and relatively inexpensive assays that can be automated to analyze large quantities of data at a time. They are used in genome-wide studies to compare gene or protein expression under two varied conditions, such as healthy and diseased states. Microarrays consist of glass or silica slides on which probe molecules are covalently attached through surface functionalization. Most commonly, the slides are prepared through the chemisorption of silanes to silica... https://www.jove.com/v/12014 154 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14371.jpg Nucleic Acid Structure The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group on the ribose's second carbon and a hydrogen on the deoxyribose's second carbon. The phosphate residue attaches to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms a 5′ to 3′ phosphodiester linkage. DNA Structure DNA has a double-helix structure. The... https://www.jove.com/v/14371 85 JoVE no https://cloudfront.jove.com/files/ftp_upload/19557/19557_article_thumb_19557.jpg Modern Molecular Taxonomy Advancements in molecular biology have revolutionized the identification and characterization of bacteria, with multiple methods leveraging DNA sequencing for enhanced precision. As sequencing technologies improve and costs decline, these approaches are increasingly used in clinical, environmental, and evolutionary studies.Multilocus Sequence Typing (MLST) examines several housekeeping genes, essential chromosomal genes encoding cellular functions, to distinguish strains. Approximately... https://www.jove.com/v/19557 89 2025-06-12T16:19:23+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56136.jpg Pattern-based Search of Epigenomic Data Using GeNemo Unlike DNA sequence data, epigenomic data are not readily subjected to text-based searches. Presented here are the procedures to use an upgraded version of GeNemo, a web-based bioinformatics tool, to conduct pattern-based searches for similarities in epigenomic data comparing available online databases including Encyclopedia of DNA Elements with user's data. https://www.jove.com/v/56136 398 2017-10-08T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59936.jpg High-Density DNA and RNA microarrays - Photolithographic Synthesis, Hybridization and Preparation of Large Nucleic Acid Libraries In this article, we present and discuss new developments in the synthesis and applications of nucleic acid microarrays fabricated in situ. Specifically, we show how the protocols for DNA synthesis can be extended to RNA and how microarrays can be used to create retrievable nucleic acid libraries. https://www.jove.com/v/59936 682 2019-08-12T21:00:00+00:00 JoVE no https://visualize.jove.com/15871051-novel-chaperonins-in-a-prokaryote monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/10690/10690_article_thumb_10690.jpg Prokaryotic Cells Prokaryotes are small unicellular organisms that include the domains—Archaea and Bacteria. Bacteria include many common organisms, such as Salmonella and E. coli, while the Archaea include extremophiles that live in harsh environments, such as volcanic springs.Like eukaryotic cells, all prokaryotic cells are surrounded by a plasma membrane, have genetic material in the form of single, circular DNA, a cytoplasm that fills the interior of the cell, and ribosomes that synthesize proteins. However,... https://www.jove.com/v/10690 111 2026-06-01T13:27:46+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/10690/10690_article_thumb_10690.jpg Prokaryotic cells Prokaryotes are small unicellular organisms that include the domains—Archaea and Bacteria. Bacteria include many common organisms, such as Salmonella and E. coli, while the Archaea include extremophiles that live in harsh environments, such as volcanic springs.Like eukaryotic cells, all prokaryotic cells are surrounded by a plasma membrane, have genetic material in the form of single, circular DNA, a cytoplasm that fills the interior of the cell, and ribosomes that synthesize proteins. However,... https://www.jove.com/v/11480 111 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11601.jpg Molecular Chaperones and Protein Folding The native conformation of a protein is formed by interactions between the side chains of its constituent amino acids. When the amino acids cannot form these interactions, the protein cannot fold by itself and needs chaperones. Notably, chaperones do not relay any additional information required for the folding of polypeptides; the native conformation of a protein is determined solely by its amino acid sequence. Chaperones catalyze protein folding without being a part of the folded protein. The... https://www.jove.com/v/11601 180 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11601.jpg Molecular Chaperones and Protein Folding The native conformation of a protein is formed by interactions between the side chains of its constituent amino acids. When the amino acids cannot form these interactions, the protein cannot fold by itself and needs chaperones. Notably, chaperones do not relay any additional information required for the folding of polypeptides; the native conformation of a protein is determined solely by its amino acid sequence. Chaperones catalyze protein folding without being a part of the folded protein. The... https://www.jove.com/v/13137 180 JoVE no https://cloudfront.jove.com/files/ftp_upload/19476/19476_article_thumb_19476.jpg Nucleoid The nucleoid represents a structurally and functionally distinct region within prokaryotic cells, where the cell's DNA and associated proteins are housed. Unlike eukaryotic cells, prokaryotes lack a membrane-bound nucleus, and the nucleoid facilitates the organization and accessibility of the genetic material within this constraint. The DNA in most bacteria and archaea exists as a single, circular, double-stranded molecule that is highly compacted through supercoiling and interactions with... https://www.jove.com/v/19476 84 2025-06-12T16:31:54+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19528/19528_article_thumb_19528.jpg Bacterial Protein Maturation Bacterial protein maturation is a tightly regulated process that ensures newly synthesized polypeptides achieve correct functional conformations. This maturation involves a series of modifications, folding events, and quality control steps, often assisted by specialized chaperone proteins.N-Terminal ModificationsThe maturation of bacterial polypeptides begins cotranslationally as the polypeptide exits the ribosome. The first amino acid, N-formylmethionine (fMet), is typically modified at the... https://www.jove.com/v/19528 86 2025-06-12T16:13:17+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54527.jpg Detection of the pH-dependent Activity of Escherichia coli Chaperone HdeB In Vitro and In Vivo This study describes biophysical, biochemical and molecular techniques to characterize the chaperone activity of Escherichia coli HdeB under acidic pH conditions. These methods have been successfully applied for other acid-protective chaperones such as HdeA and can be modified to work for other chaperones and stress conditions. https://www.jove.com/v/54527 512 2016-10-23T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60172.jpg In Situ Monitoring of Transiently Formed Molecular Chaperone Assemblies in Bacteria, Yeast, and Human Cells Cognate J-domain proteins cooperate with the Hsp70 chaperone to assist in a myriad of biological processes ranging from protein folding to degradation. Here, we describe an in situ proximity ligation assay, which allows the monitoring of these transiently formed chaperone machineries in bacterial, yeast and human cells. https://www.jove.com/v/60172 538 2019-09-02T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66515.jpg Escherichia coli -Based Complementation Assay to Study the Chaperone Function of Heat Shock Protein 70 This protocol demonstrates the chaperone activity of heat shock protein 70 (Hsp70). E. coli dnaK756 cells serve as a model for the assay as they harbor a native, functionally impaired Hsp70, making them susceptible to heat stress. The heterologous introduction of functional Hsp70 rescues the growth deficiency of the cells. https://www.jove.com/v/66515 434 2024-03-08T22:25:00+00:00 JoVE no https://visualize.jove.com/15877616-increased-intensity-of-anticoagulation-may-reduce-risk-of-thrombus-during-atrial-fibrillation-ablation-procedures-in-patients-with-spontaneous-echo-contrast monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15031.jpg Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers Class III antiarrhythmic drugs are a group of medications that can prolong action potentials in the heart. They achieve this by blocking potassium channels or enhancing inward currents from sodium channels. However, these drugs have a unique property of "reverse use-dependence," which is most pronounced at slower heart rates and can lead to torsades de pointes—a specific type of arrhythmia. However, it is essential to note that excessive QT interval prolongation—a measure of the heart's... https://www.jove.com/v/15031 72 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15039.jpg Anticoagulant Drugs: Low-Molecular-Weight Heparins Hemostasis is a crucial process that prevents excessive blood loss from damaged blood vessels. It involves various mechanisms such as vasoconstriction, platelet adhesion and activation, and fibrin formation. The importance of each mechanism depends on the type of vessel injury. In contrast, thrombosis is the abnormal formation of a blood clot within the blood vessels, leading to potential complications if the clot obstructs blood flow. Thrombosis can be caused by increased coagulability of the... https://www.jove.com/v/15039 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15040.jpg Anticoagulant Drugs: Vitamin K Antagonists and Direct Oral Anticoagulants Oral anticoagulants are vital tools in preventing and treating blood clotting disorders. This diverse class of medications can be categorized as vitamin K antagonists, exemplified by warfarin, and direct thrombin inhibitors (DTIs), such as dabigatran, as well as factor Xa inhibitors, including rivaroxaban. Warfarin, a prominent vitamin K antagonist family member, exerts its effect by inhibiting the enzyme VKORC1 (vitamin K epoxide reductase complex 1). By hindering this enzyme, warfarin... https://www.jove.com/v/15040 78 JoVE no https://cloudfront.jove.com/files/ftp_upload/17888/17888_article_thumb_17888.jpg Cardiac Catheterization I: Pre-Procedure Overview Cardiac catheterization is an invasive diagnostic technique used to identify and evaluate structural and functional diseases of the heart and major blood vessels. This technique diagnoses congenital heart disease, coronary artery disease, valvular heart disease, and coronary spasms and assesses ventricular function. It helps guide treatment decisions, including the need for revascularization procedures like percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) and... https://www.jove.com/v/17888 88 2025-06-19T16:14:01+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17987/17987_article_thumb_17987.jpg Venous Thrombosis III: Interprofessional Care Venous thrombosis requires effective prevention and treatment strategies to improve patient outcomes and reduce potential complications.Prevention StrategiesHealthcare providers must prioritize preventing venous thromboembolism (VTE) for all adult patients upon admission. Interventions depend on bleeding and thrombosis risk, medical history, current medications, diagnoses, planned procedures, and patient preferences. Patients on bed rest should change positions every two hours and, if not... https://www.jove.com/v/17987 89 2025-06-19T16:20:31+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18437/18437_article_thumb_18437.jpg ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias Arrhythmia is a condition characterized by an irregular heart rhythm, with ECG changes that differ based on its origin and nature. The types of arrhythmias discussed below include atrial, junctional, and ventricular arrhythmias.Atrial ArrhythmiasPremature Atrial Complexes (PACs): PACs are early atrial beats caused by stress, caffeine, alcohol, electrolyte imbalances, hypoxia, hyperthyroidism, or certain medications (e.g., bronchodilators and decongestants). The ECG shows early P waves with an... https://www.jove.com/v/18437 85 2025-06-19T16:15:27+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52606.jpg Non-fluoroscopic Catheter Tracking for Fluoroscopy Reduction in Interventional Electrophysiology Radiation exposure is an underestimated risk in complex ablation procedures. Here, we describe a protocol to significantly decrease fluoroscopy time and dosage for both the patient and the lab staff by using a novel non-fluoroscopic catheter visualization system. https://www.jove.com/v/52606 646 2015-05-26T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64417.jpg Reduced Procedure Time and Variability with Active Esophageal Cooling During Radiofrequency Ablation for Atrial Fibrillation This study utilized advanced informatics techniques to compare procedure duration in patients undergoing radiofrequency atrial ablation treated with active esophageal cooling to those treated with traditional luminal esophageal temperature monitoring. Contextual inquiry, workflow analysis, and data mapping were utilized. The findings demonstrated reduced procedure time and variability with active cooling. https://www.jove.com/v/64417 298 2022-08-25T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66688.jpg Determination of Continuity Index Values in Atrial Fibrillation Ablation with Proactive Esophageal Cooling This protocol describes the methods used to determine the continuity index in patients undergoing pulmonary vein isolation procedures using radiofrequency ablation and demonstrates the differences in continuity index between ablation procedures using proactive esophageal cooling as compared to procedures using traditional luminal esophageal temperature monitoring. https://www.jove.com/v/66688 343 2024-04-19T21:35:00+00:00 JoVE no https://visualize.jove.com/15877812-adeno-associated-virus-from-defective-virus-to-effective-vector monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/58960.jpg Production, Purification, and Quality Control for Adeno-associated Virus-based Vectors Here, we describe an efficient and reproducible strategy to produce, titer, and quality-control batches of adeno-associated virus vectors. It allows the user to obtain a vector preparation with high-titer (≥1 x 1013 vector genomes/mL) and a high purity, ready for in vitro or in vivo... https://app.jove.com/v/58960 561 38500 2019-01-29T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65572.jpg Author Spotlight: Unveiling the Potential of Unpurified Recombinant AAVs in Cell Culture Research Recombinant adeno-associated virus (rAAV) is widely used for clinical and preclinical gene delivery. An underappreciated use for rAAVs is the robust transduction of cultured cells without the need for purification. For researchers new to rAAV, we provide a protocol for transgene cassette cloning, crude vector production, and cell culture transduction. https://app.jove.com/v/65572 401 4700 2023-10-20T21:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66550.jpg Author Spotlight: Improved Method for Production and Purification of Adeno-Associated Viral Vectors This manuscript describes a detailed protocol for the generation and purification of adeno-associated viral vectors using an optimized heparin-based affinity chromatography method. It presents a simple, scalable, and cost-effective approach, eliminating the need for ultracentrifugation. The resulting vectors exhibit high purity and biological activity, proving their value in preclinical... https://app.jove.com/v/66550 552 5100 2024-04-05T21:20:00+00:00 JoVE no https://visualize.jove.com/15925427-simulation-system-of-arrhythmia-using-activex-control monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15028.jpg Mechanism of Cardiac Arrhythmias Arrhythmias are irregular heart rhythms occurring when the heart's electrical impulses become abnormal. These disturbances can lead to various symptoms, depending on their severity and the underlying cause. Some common factors contributing to arrhythmias include hypoxia, ischemia, electrolyte imbalances, excessive catecholamine exposure, drug toxicity, and muscle overstretching. Arrhythmias can be classified into two main types based on the rate and site of origin of abnormal heart rhythms. https://app.jove.com/v/15028 88 2700 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15272.jpg Conduction System of the Heart Autorhythmicity is a term that refers to the heart's inherent ability to generate electrical signals and instigate muscle contractions. This self-regulating conduction system within the heart consists of two key components: the pacemaker cells and specialized conducting cells. The pacemaker cells are located in two primary nodes: the sinoatrial (SA) node and the atrioventricular (AV) node. The SA node pacemaker cells can autonomously depolarize, triggering an action potential that leads to the... https://app.jove.com/v/15272 79 13500 2025-05-15T16:15:50+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15276.jpg Disturbances in Heart Rhythm Arrhythmia or dysrhythmia refers to an abnormal heart rhythm caused by a defect in the heart's conduction system. It can cause the heart to beat irregularly, too quickly, or too slowly, leading to symptoms like chest pain, shortness of breath, and fainting. Factors such as stress, caffeine, alcohol, nicotine, cocaine, certain drugs, congenital defects, diseases, and electrolyte abnormalities can trigger arrhythmias. Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart... https://app.jove.com/v/15276 89 5300 2025-07-29T16:29:05+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17863.jpg Conduction System of the Heart The cardiac conduction system produces and transmits electrical impulses that prompt myocardial contraction, ensuring efficient heart function. This intricate system ensures that the heart beats in a coordinated and efficient manner, beginning with the atria and then the ventricles. The conduction system optimizes cardiac output by maintaining this precise sequence, which is crucial for adequate blood circulation. This system relies on the unique properties of nodal and Purkinje cells:... https://app.jove.com/v/17863 80 6100 JoVE no https://cloudfront.jove.com/files/ftp_upload/17938/17938_article_thumb_17938.jpg Dysrhythmias I: Introduction Dysrhythmias refers to abnormalities in the heart's rhythm. They result from disruptions in the heart's electrical conduction system, which includes the sinoatrial(SA)node, atrioventricular(AV) node, the bundle of His, bundle branches, and Purkinje fibers.Definition and PathophysiologyDysrhythmias result from disorders of impulse formation, impulse conduction, or both. The heart contains specialized cells in the sinoatrial node, atrioventricular node, and the bundle of His and Purkinje fibers... https://app.jove.com/v/17938 75 730 2025-06-19T16:35:29+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17943/17943_article_thumb_17943.jpg Dysrhythmias VI: Management of Dysrhythmias Dysrhythmia management involves a multifaceted approach, incorporating pharmacological treatments, medical procedures, surgical interventions, lifestyle modifications, and patient education.Pharmacological ManagementAntiarrhythmic Drugs:Class I (Sodium Channel Blockers): This class includes quinidine and procainamide, which reduce the speed of impulse conduction in the heart, stabilize the cardiac membrane, and control arrhythmias. Quinidine and procainamide are Class IA agents that prolong the... https://app.jove.com/v/17943 85 597 2025-06-19T16:37:04+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50125.jpg Patient-specific Modeling of the Heart: Estimation of Ventricular Fiber Orientations A methodology to estimate ventricular fiber orientations from in vivo images of patient heart geometries for personalized modeling is described. Validation of the methodology performed using normal and failing canine hearts demonstrate that that there are no significant differences between estimated and acquired fiber orientations at a clinically observable... https://app.jove.com/v/50125 729 13200 2013-01-08T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52600.jpg Testing the Efficacy of Pharmacological Agents in a Pericardial Target Delivery Model in the Swine We have developed a swine model for the target delivery of pharmacological agents within the pericardial space/fluid. Using this approach, the relative benefits of administered agents on induced atrial fibrillation, relative refractory periods and/or ischemic protection can be investigated. https://app.jove.com/v/52600 605 7900 2016-07-07T16:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55797.jpg Assessment of Sarcoplasmic Reticulum Calcium Reserve and Intracellular Diastolic Calcium Removal in Isolated Ventricular Cardiomyocytes Intracellular calcium recycling plays a critical role in regulation of systolic and diastolic function in cardiomyocytes. Here, we describe a protocol to evaluate sarcoplasmic reticulum Ca2+ reserve and diastolic calcium removal function in cardiomyocytes by a calcium imaging... https://app.jove.com/v/55797 660 9200 2017-09-18T20:00:00+00:00 JoVE no https://visualize.jove.com/15972119-adult-stem-cells-and-possible-mechanisms-of-its-differentiation-editorial monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10810.jpg Adult Stem Cells Stem cells are undifferentiated cells that divide and produce more stem cells or progenitor cells that differentiate into mature, specialized cell types. All the cells in the body are generated from stem cells in the early embryo, but small populations of stem cells are also present in many adult tissues including the bone marrow, brain, skin, and gut. These adult stem cells typically produce the various cell types found in that tissue—to replace cells that are damaged or to continuously renew... https://www.jove.com/v/10810 93 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10811.jpg Embryonic Stem Cells Embryonic stem (ES) cells are undifferentiated pluripotent cells, meaning they can produce any cell type in the body. This gives them tremendous potential in science and medicine since they can generate specific cell types for use in research or to replace body cells lost due to damage or disease. Origin ES cells are present in the inner cell mass of an embryo at the blastocyst stage, which occurs at about 3–5 days after fertilization in humans before the embryo is implanted in the uterus. https://www.jove.com/v/10811 58 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13462.jpg Source And Potency Of Stem Cells Stem cells are undifferentiated cells with extensive self-renewal properties that help them maintain their population during the fetal and adult stages of life. They can specialize in all cell types of the human body. However, their differential potential may vary and can be classified into five types. Stem cells can be (1) Totipotent, (2) Pluripotent, (3) Multipotent, (4) Oligopotent, and (5) Unipotent. Each stem cell has a specific origin; the fertilized egg or zygote is a totipotent cell and... https://www.jove.com/v/13462 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13469.jpg Distinctive Features of Adult Stem Cells vs Cancer Stem Cells A stem cell is an unspecialized cell that can divide without limit as needed and can, under specific conditions, differentiate into specialized cells. Adult stem cells Adult stem cells are tissue-specific; hence, they divide to develop the tissue from which they originate. One type of adult stem cell is the epithelial stem cell, which gives rise to the keratinocytes in the multiple layers of epithelial cells in the epidermis of the skin. Adult bone marrow has three distinct types of stem cells:... https://www.jove.com/v/13469 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13470.jpg Stem Cell Culture Stem cell research aims to find ways to use stem cells to regenerate and repair cellular damage. Over time, most adult cells undergo the wear and tear of aging and lose their ability to divide and repair themselves. Stem cells do not display a particular morphology or function. Adult stem cells, which exist as a small subset of cells in most tissues, keep dividing and can differentiate into a number of specialized cells generally formed by that tissue. These cells enable the body to renew and... https://www.jove.com/v/13470 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13478.jpg Embryonic Stem Cells Embryonic stem (ES) cells were first discovered in mice in 1981 by Martin Evans. In 1998, James Thomson identified a method to isolate embryonic stem cells from humans. Human embryonic stem cells (hESCs) are obtained from 3-5 day old embryos that remain unused after an in vitro fertilization procedure. ES cells are grown in a culture medium where they can divide indefinitely, creating ES cell lines. Under certain conditions, ES cells can differentiate, either spontaneously into a variety of... https://www.jove.com/v/13478 57 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51737.jpg Directed Dopaminergic Neuron Differentiation from Human Pluripotent Stem Cells We, based on knowledge from developmental biology and published research, developed an optimized protocol to efficiently generate A9 midbrain dopaminergic neurons from both human embryonic stem cells and human induced pluripotent stem cells, which would be useful for disease modeling and cell replacement therapy for Parkinson’s disease. https://www.jove.com/v/51737 400 2014-09-15T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52410.jpg Differentiation of a Human Neural Stem Cell Line on Three Dimensional Cultures, Analysis of MicroRNA and Putative Target Genes With the intent of characterizing changes in miRNAs on differentiated human neural stem cells (hNSCs) we describe hNSC differentiation on a three dimensional system,the evaluation of changes in microRNA expression by miRNA PCR array, and computational analysis for miRNA target prediction and its validation by dual luciferase assay. https://www.jove.com/v/52410 648 2015-04-12T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53874.jpg Epigenetic Regulation of Cardiac Differentiation of Embryonic Stem Cells and Tissues A fine tuning regulation of gene transcription underlies embryonic cell fate decision. Herein, we describe chromatin immunoprecipitation assays used to investigate epigenetic regulation of both cardiac differentiation of stem cells and cardiac development of mouse embryos. https://www.jove.com/v/53874 783 2016-06-03T21:00:00+00:00 JoVE no https://visualize.jove.com/16009546-learning-induced-plasticity-in-animal-and-human-auditory-cortex monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10853.jpg Hearing When we hear a sound, our nervous system is detecting sound waves—pressure waves of mechanical energy traveling through a medium. The frequency of the wave is perceived as pitch, while the amplitude is perceived as loudness. Sound waves are collected by the external ear and amplified as they travel through the ear canal. When sounds reach the junction between the outer and middle ear, they vibrate the tympanic membrane—the eardrum. The resulting mechanical energy causes the attached ossicles—a... https://www.jove.com/v/10853 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10855.jpg The Cochlea The cochlea is a coiled structure in the inner ear that contains hair cells—the sensory receptors of the auditory system. Sound waves are transmitted to the cochlea by small bones attached to the eardrum called the ossicles, which vibrate the oval window that leads to the inner ear. This causes fluid in the chambers of the cochlea to move, vibrating the basilar membrane. The basilar membrane extends from the basal end of the cochlea near the oval window to the apical end at its tip. Although... https://www.jove.com/v/10855 73 2025-10-23T18:49:24+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12730.jpg Plasticity Plasticity is the property where an object loses its elasticity and undergoes irreversible deformation, even after the deformation forces are eliminated. If a material deforms irreversibly without increasing stress or load, then this is called ideal plasticity. For example, when a force is applied to an aluminum rod, it changes its shape, but it does not return to its original shape once the force is removed. Plastic deformation or ductility is thus a permanent deformation or change in the... https://www.jove.com/v/12730 58 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14970.jpg Auditory Pathway Auditory pathways constitute the complex neural circuits responsible for transmitting and interpreting auditory information from the peripheral auditory system to the brain. Sound waves are initially captured by the outer ear, funneled through the ear canal, and reach the tympanic membrane (eardrum). These vibrations are transmitted via the middle ear's ossicles to the inner ear's cochlea. When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking the... https://www.jove.com/v/14970 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17745.jpg Neuroplasticity Neuroplasticity reflects the brain's remarkable capacity to adapt and evolve, responding dynamically to learning, experiences, or injury by reorganizing its neural circuitry. This reorganization involves creating new neural connections and refining old ones through a series of biological processes that contribute to the brain's lifelong development and adaptability. • The brain's ability to change begins with the growth of dendrites and axons, which effectively increases the structural... https://www.jove.com/v/17745 61 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17771.jpg Auditory Perception The auditory system is essential for sound perception, utilizing various critical structures. When sound waves enter the outer ear, they travel through the ear canal and cause the eardrum to vibrate. These vibrations are then transmitted to the middle ear, where three tiny bones – the malleus, incus, and stapes – amplify the sound. This amplification is crucial, as it ensures that the sound vibrations are strong enough to be conveyed to the inner ear. These vibrations then reach the cochlea, a... https://www.jove.com/v/17771 77 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50872.jpg Functional Imaging of Auditory Cortex in Adult Cats using High-field fMRI Functional studies of the auditory system in mammals have traditionally been conducted using spatially-focused techniques such as electrophysiological recordings. The following protocol describes a method of visualizing large-scale patterns of evoked hemodynamic activity in the cat auditory cortex using functional magnetic resonance imaging. https://www.jove.com/v/50872 650 2014-02-19T22:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53002.jpg Combined Shuttle-Box Training with Electrophysiological Cortex Recording and Stimulation as a Tool to Study Perception and Learning Shuttle-box avoidance learning is well-established in behavioral neuroscience. This protocol describes how shuttle-box learning in rodents can be combined with site-specific electrical intracortical microstimulation (ICMS) and simultaneous chronical in vivo recordings as a tool to study multiple aspects of learning and perception. https://www.jove.com/v/53002 523 2015-10-22T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56429.jpg Stereotactically-guided Ablation of the Rat Auditory Cortex, and Localization of the Lesion in the Brain We describe a method for the stereotactically-guided location, exposure, and ablation of the auditory cortex in rats. The localization of the ablation is assessed using a coordinate map postmortem. https://www.jove.com/v/56429 569 2017-10-11T19:30:00+00:00 JoVE no https://visualize.jove.com/16039016-enhanced-multisensory-integration-in-older-adults monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10859.jpg Somatosensation The somatosensory system relays sensory information from the skin, mucous membranes, limbs, and joints. Somatosensation is more familiarly known as the sense of touch. A typical somatosensory pathway includes three types of long neurons: primary, secondary, and tertiary. Primary neurons have cell bodies located near the spinal cord in groups of neurons called dorsal root ganglia. The sensory neurons of ganglia innervate designated areas of skin called dermatomes. In the skin, specialized... https://www.jove.com/v/10859 93 2025-10-23T18:49:22+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14931.jpg Sensory Modalities Sensation typically is the process by which the sensory receptors and sense organs detect stimuli from the internal and external environment and transmit this information to the central nervous system for processing. General senses refer to the broad category of sensory information detected by receptors in the body and can be further grouped into somatic and visceral senses. Somatic sensations include touch, pressure, temperature, and pain and are essential for navigating our environment and... https://www.jove.com/v/14931 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14933.jpg Sensory Perception: Organization of the Somatosensory System The somatosensory system is the central and peripheral nervous system component that senses and processes touch, pressure, pain, temperature, and body position or proprioception. The process of sensation takes place at three levels: The receptor level: The receptor level is the first stage of sensation. It involves the detection of a stimulus by specialized sensory receptors. The stimulus must arrive within the receptor's receptive field. Next, the receptor converts the energy of the stimulus... https://www.jove.com/v/14933 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14935.jpg Major Somatic Sensory Pathways Sensory impulses related to touch, pressure, vibration, and proprioception from various body parts, such as the limbs, trunk, neck, and posterior head, travel to the cerebral cortex through the posterior column-medial lemniscus pathway. The pathway’s name derives from the two white-matter tracts that convey the impulses: the spinal cord's posterior column and the brainstem's medial lemniscus. First-order sensory neurons extend their axons into the spinal cord, forming the posterior columns... https://www.jove.com/v/14935 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18559.jpg Cognitive Development During Adulthood Cognitive development continues throughout adulthood, undergoing significant shifts across early, middle, and late stages. Individual transition occurs from adolescent idealism to pragmatic and adaptable thinking in early adulthood. During this period, individuals learn to integrate personal beliefs with the recognition that other perspectives are equally valid. Exposure to the complexities of modern society, diverse experiences, and higher education contribute to this adaptive thought process,... https://www.jove.com/v/18559 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52677.jpg Testing Sensory and Multisensory Function in Children with Autism Spectrum Disorder We describe how to implement a battery of behavioral tasks to examine the processing and integration of sensory stimuli in children with ASD. The goal is to characterize individual differences in temporal processing of simple auditory and visual stimuli and relate these to higher order perceptual skills like speech perception. https://www.jove.com/v/52677 553 2015-04-22T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58823.jpg Multi-Modal Home Sleep Monitoring in Older Adults Here, we present a protocol to improve the quality of data from home sleep testing by providing a method to enhance instructions through a structured participant visit. This protocol includes the implementation of a step-by-step educational manual with photos to ensure proper placement of equipment. https://www.jove.com/v/58823 460 2019-01-26T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59575.jpg Using the Race Model Inequality to Quantify Behavioral Multisensory Integration Effects The current study aims to provide a step-by-step tutorial for calculating the magnitude of multisensory integration effects in an effort to facilitate the production of translational research studies across diverse clinical populations. https://www.jove.com/v/59575 493 2019-05-10T21:45:00+00:00 JoVE no https://visualize.jove.com/16083507-artificial-neural-networks-for-diagnosis-and-survival-prediction-in-colon-cancer monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17623.jpg Cancer Survival Analysis Cancer survival analysis focuses on quantifying and interpreting the time from a key starting point, such as diagnosis or the initiation of treatment, to a specific endpoint, such as remission or death. This analysis provides critical insights into treatment effectiveness and factors that influence patient outcomes, helping to shape clinical decisions and guide prognostic evaluations. A cornerstone of oncology research, survival analysis tackles the challenges of skewed, non-normally... https://www.jove.com/v/17623 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61235.jpg Machine Learning Algorithms for Early Detection of Bone Metastases in an Experimental Rat Model This protocol was designed to train a machine learning algorithm to use a combination of imaging parameters derived from magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) in a rat model of breast cancer bone metastases to detect early metastatic disease and predict subsequent progression to macrometastases. https://www.jove.com/v/61235 435 2020-08-16T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67433.jpg Competing-Risk Nomogram for Predicting Cancer-Specific Survival in Multiple Primary Colorectal Cancer Patients after Surgery The study found that male gender, poor tumor grade, and advanced Tumor Node Metastasis stage were associated with poorer cancer-specific survival (CSS) in multiple primary colorectal cancer (MPCC) patients after surgery. We developed a nomogram to predict the CSS of MPCC patients and contribute to clinical treatment decision-making. https://www.jove.com/v/67433 406 2024-09-27T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67941.jpg Comparison of Predictive Performance of Three Lymph Node Staging Systems in Colorectal Signet Ring Cell Carcinoma Based on Machine Learning Model This study evaluates prognostic systems for colorectal signet-ring cell carcinoma patients using machine learning models and competing risk analyses. It identifies log odds of positive lymph nodes as a superior predictor compared to pN staging, demonstrating strong predictive performance and aiding clinical decision-making through robust survival prediction tools. https://www.jove.com/v/67941 433 2025-04-18T21:00:00+00:00 JoVE no https://visualize.jove.com/16090877-discrete-talbot-effect-in-waveguide-arrays monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4304.jpg Terahertz Microfluidic Sensing Using a Parallel-plate Waveguide Sensor The procedure for implementing a refractive index sensor for terahertz frequencies based on a grooved parallel-plate waveguide geometry is described here. The method yields a measurement of the refractive index of a small volume of liquid through monitoring of the shift in the resonant frequency of the waveguide... https://www.jove.com/v/4304 448 2012-08-30T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11296.jpg Interference and Diffraction Interference is a characteristic phenomenon exhibited by waves. When two electromagnetic waves interact with their peaks and troughs coinciding, a resulting wave with enhanced amplitude is produced. This is known as constructive interference. In this case, the two waves interacting are in phase with each other. Alternatively, if the two waves coincide and interact in a way such that the trough of one wave coincides with the peak of the other (in an out of phase manner), the resultant wave will... https://www.jove.com/v/11296 138 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11300.jpg The de Broglie Wavelength In the macroscopic world, objects that are large enough to be seen by the naked eye follow the rules of classical physics. A billiard ball moving on a table will behave like a particle; it will continue traveling in a straight line unless it collides with another ball, or it is acted on by some other force, such as friction. The ball has a well-defined position and velocity or well-defined momentum, p = mv, which is defined by mass m and velocity v at any given moment. This is the typical... https://www.jove.com/v/11300 152 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14213.jpg Standing Waves in a Cavity A household microwave and lasers are examples of standing electromagnetic waves in a cavity. When two conducting metal plates are placed parallel at the nodal planes, it creates a cavity where standing waves are formed. The cavity between the two planes is analogous to a stretched string held at the points x = 0 and x = L. Here, the distance 'L' between the two planes must be an integer multiple of half of the wavelength. The wavelengths that satisfy this condition are given by: The... https://www.jove.com/v/14213 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16065.jpg Discrete-Time Fourier Series The Discrete-Time Fourier Series (DTFS) is a fundamental concept in signal processing, serving as the discrete-time counterpart to the continuous-time Fourier series. It allows for the representation and analysis of discrete-time periodic signals in terms of their frequency components. Unlike its continuous counterpart, which utilizes integrals, the calculation of DTFS expansion coefficients involves summations due to the discrete nature of the signal. For a discrete-time periodic signal x[n]... https://www.jove.com/v/16065 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16175.jpg Traveling Waves: Lossless Lines The provided content explores the behavior of traveling waves on single-phase lossless transmission lines. It begins with a single-phase two-wire lossless transmission line of length Δx, characterized by a loop inductance LH/m and a line-to-line capacitance C F/m. These parameters result in a series inductance LΔx and a shunt capacitance CΔx. The voltage v(x,t) and current i(x,t) at any position x and time t on the line are expressed using Kirchhoff's Voltage Law (KVL) and Kirchhoff's Current... https://www.jove.com/v/16175 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16177.jpg Bewley Lattice Diagram The Bewley lattice diagram, developed by L. V. Bewley, effectively organizes the reflections occurring during transmission-line transients. It visually represents how voltage waves propagate and reflect within a transmission line, making it easier to understand the complex interactions that occur. In the diagram, the vertical scale represents the line's transient time, while the horizontal scale represents the line position x. The diagonal lines in the diagram represent traveling waves. Each... https://www.jove.com/v/16177 72 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50216.jpg Fabrication And Characterization Of Photonic Crystal Slow Light Waveguides And Cavities Use of photonic crystal slow light waveguides and cavities has been widely adopted by the photonics community in many differing applications. Therefore fabrication and characterization of these devices are of great interest. This paper outlines our fabrication technique and two optical characterization methods, namely: interferometric (waveguides) and resonant scattering (cavities). https://www.jove.com/v/50216 668 2012-11-30T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51614.jpg Using Microwave and Macroscopic Samples of Dielectric Solids to Study the Photonic Properties of Disordered Photonic Bandgap Materials Disordered structures offer new mechanisms for forming photonic bandgaps and unprecedented freedom in functional-defect designs. To circumvent the computational challenges of disordered systems, we construct modular macroscopic samples of the new class of PBG materials and use microwaves to characterize their scale-invariant photonic properties, in an easy and inexpensive manner. https://www.jove.com/v/51614 635 2014-09-26T20:00:00+00:00 JoVE no https://visualize.jove.com/16105221-coding-of-temporally-varying-signals-in-networks-of-spiking-neurons-with-global-delayed-feedback monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11895.jpg Synaptic Signaling Neurons communicate at synapses, or junctions, to excite or inhibit the activity of other neurons or target cells, such as muscles. Synapses may be chemical or electrical. Most synapses are chemical, meaning an electrical impulse or action potential spurs the release of chemical messengers called neurotransmitters. The neuron sending the signal is called the presynaptic neuron, and the neuron receiving the signal is the postsynaptic neuron. The presynaptic neuron fires an action potential that... https://www.jove.com/v/11895 69 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12184.jpg The Role of Ion Channels in Neuronal Computation A postsynaptic neuron usually receives numerous impulses from several other presynaptic neurons. The axon hillock of the postsynaptic neuron integrates all these signals and determines the likelihood of firing an action potential. Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential. https://www.jove.com/v/12184 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14891.jpg Graded Potential Graded potentials are localized fluctuations in the cell membrane's electrical charge, commonly found in the dendrites of neurons. The magnitude of these potential changes depends on the strength of the initiating stimulus. In a membrane at its resting potential, a graded potential signifies a voltage shift either above -70 mV or below -70 mV. Graded potentials fall into two categories: depolarizing and hyperpolarizing. Depolarizing graded potentials typically occur when sodium (Na+) or calcium... https://www.jove.com/v/14891 79 JoVE no https://cloudfront.jove.com/files/ftp_upload/14894/14894_article_thumb_14894.jpg Propagation of Action Potentials The propagation of an action potential refers to the process by which a nerve impulse, or "action potential," travels along a neuron. Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to... https://www.jove.com/v/14894 83 2025-08-11T22:39:58+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14900.jpg Neural Circuits Neural circuits and neuronal pools are two of the main structures found in the nervous system. Neural circuits are networks of neurons that work together to carry out a specific task or process. They consist of interconnected neurons and glial cells, which provide structural and metabolic support. Neuronal pools are collections of nerve cells with similar functions and interact through chemical and electrical signals. These pools include both interneurons (the central neural circuit nodes that... https://www.jove.com/v/14900 85 2025-06-13T16:07:11+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17743.jpg Neuronal Communication Neurons, the fundamental units of the brain and nervous system, communicate through complex electrochemical signals that underpin all cognitive and bodily functions. This communication is primarily facilitated by a process involving the generation and propagation of an action potential along the axon of the neuron. When the internal electrical charge of a neuron surpasses a certain threshold, an action potential is triggered. This rapid change in voltage travels swiftly along the axon to the... https://www.jove.com/v/17743 88 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52320.jpg Real-time Electrophysiology: Using Closed-loop Protocols to Probe Neuronal Dynamics and Beyond Closed-loop protocols are becoming increasingly widespread in modern day electrophysiology. We present a simple, versatile and inexpensive way to perform complex electrophysiological protocols in cortical pyramidal neurons in vitro, using a desktop computer and a digital acquisition board. https://www.jove.com/v/52320 488 2015-06-24T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55726.jpg Time-dependent Increase in the Network Response to the Stimulation of Neuronal Cell Cultures on Micro-electrode Arrays Mouse neuronal cells cultured on multi-electrode arrays display an increase in response following electrical stimulation. This protocol demonstrates how to culture neurons, how to record activity, and how to establish a protocol to train the networks to respond to patterns of stimulation. https://www.jove.com/v/55726 645 2017-05-29T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59812.jpg Using Neuron Spiking Activity to Trigger Closed-Loop Stimuli in Neurophysiological Experiments This protocol demonstrates how to use an electrophysiological system for closed-loop stimulation triggered by neuronal activity patterns. Sample Matlab code that can be easily modified for different stimulation devices is also provided. https://www.jove.com/v/59812 319 2019-11-12T19:00:00+00:00 JoVE no https://visualize.jove.com/16151842-detailed-and-abstract-phase-locked-attractor-network-models-of-early-olfactory-systems monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10852.jpg Olfaction The sense of smell is achieved through the activities of the olfactory system. It starts when an airborne odorant enters the nasal cavity and reaches olfactory epithelium (OE). The OE is protected by a thin layer of mucus, which also serves the purpose of dissolving more complex compounds into simpler chemical odorants. The size of the OE and the density of sensory neurons varies among species; in humans, the OE is only about 9-10 cm2. The olfactory receptors are embedded in the cilia of the... https://www.jove.com/v/10852 85 2025-10-23T18:49:25+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14965.jpg Olfactory Receptors: Location and Structure The process of olfaction, also known as the sense of smell, is a sophisticated chemical response system. The specialized sensory neurons that facilitate this process, known as olfactory receptor neurons, are situated in an upper segment of the nasal cavity, known as the olfactory epithelium. Olfactory sensory neurons are bipolar, with their dendrites extending from the epithelium's apex into the mucus that lines the nasal cavity. Airborne molecules, when inhaled, traverse the olfactory... https://www.jove.com/v/14965 63 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14966.jpg Physiology of Smell and Olfactory Pathway Humans detect odors with the help of specialized cells located in the upper part of the nasal cavity, called olfactory receptor neurons (ORNs). ORNs possess hair-like structures called cilia, which are receptive to sensations from the inhaled air. When an odorant molecule binds to a specific receptor on the cell of the cilia, it leads to a series of events that ultimately cause the ORN to send electrical signals to the olfactory bulb in the brain through the olfactory nerves. The olfactory... https://www.jove.com/v/14966 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50139.jpg Multi-unit Recording Methods to Characterize Neural Activity in the Locust ( Schistocerca Americana ) Olfactory Circuits We demonstrate variations of the extracellular multi-unit recording technique to characterize odor-evoked responses in the first three stages of the invertebrate olfactory pathway. These techniques can easily be adapted to examine ensemble activity in other neural systems as well. https://www.jove.com/v/50139 733 2013-01-25T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52143.jpg The Olfactory System as a Model to Study Axonal Growth Patterns and Morphology In Vivo We describe a protocol for in vivo labeling of olfactory sensory neurons by electroporation and subsequent confocal laser-scanning or multiphoton microscopy to visualize neuronal morphology and its development over time. https://www.jove.com/v/52143 509 2014-10-30T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62983.jpg An Explant System for Time-Lapse Imaging Studies of Olfactory Circuit Assembly in Drosophila This protocol describes the dissection procedure, culture condition, and live imaging of an antennae-brain explant system for the study of the olfactory circuit assembly. https://www.jove.com/v/62983 426 2021-10-13T21:45:00+00:00 JoVE no https://visualize.jove.com/16171965-synthesizing-cellular-intelligence-and-artificial-intelligence-for-bioprocesses monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12037.jpg Synthetic Biology Synthetic biology is an interdisciplinary science that involves using principles from disciplines such as engineering, molecular biology, cell biology, and systems biology. It involves remodeling existing organisms from nature or constructing completely new synthetic organisms for applications such as protein or enzyme production, bioremediation, value-added macromolecule production, and the addition of desirable traits to crops, to name a few. Golden rice Golden rice is a genetically modified... https://www.jove.com/v/12037 175 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12157.jpg Non-equilibrium in the Cell An important concept in studying metabolism and energy is that of chemical equilibrium. Most chemical reactions are reversible. They can proceed in both directions, releasing energy into their environment in one direction, and absorbing it from the environment in the other direction. The same is true for the chemical reactions involved in cell metabolism, such as the breaking down and building up of proteins into and from individual amino acids, respectively. Reactants within a closed system... https://www.jove.com/v/12157 76 JoVE no https://cloudfront.jove.com/files/ftp_upload/19495/19495_article_thumb_19495.jpg Biosynthesis in Bacteria Biosynthesis in bacteria is a fundamental anabolic process that generates essential macromolecules, including proteins, nucleic acids, lipids, and polysaccharides. These macromolecules are critical for cellular growth, replication, and function. The process is tightly regulated and energetically linked to catabolic pathways to ensure optimal resource utilization.Biosynthetic pathways begin with precursor metabolites such as pyruvate, acetyl-CoA, and glucose-6-phosphate derived from glycolysis,... https://www.jove.com/v/19495 84 2025-06-12T16:36:54+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40768/40768_article_thumb_40768.jpg Bioreactor Design and Operational System Bioreactors are engineered vessels designed to cultivate microorganisms under controlled conditions for industrial bioprocessing. They maintain sterility and allow precise regulation of pH, temperature, oxygen, and nutrient levels to optimize microbial growth and metabolite production. Bioreactors range from small laboratory units of 1 liter to industrial systems holding up to 500,000 liters, though only about 75% of their volume is actively used for fermentation. The remaining headspace... https://www.jove.com/v/40768 89 2026-03-12T20:57:31+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40771/40771_article_thumb_40771.jpg Bioreactor Controls-III Strain improvement is a foundational strategy in industrial microbiology aimed at maximizing microbial productivity, particularly because natural isolates typically yield commercially valuable products in very low concentrations. Although optimizing the culture medium and environmental conditions can improve yields, these adjustments are inherently limited by the organism’s genetic potential. As a result, the focus shifts toward genetic modifications to enhance biosynthetic capacity. The... https://www.jove.com/v/40771 82 2026-03-12T20:57:27+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40777/40777_article_thumb_40777.jpg Upstream Processing Upstream processing represents a critical phase in biomanufacturing, wherein biological systems such as microorganisms, mammalian cells, or insect cells are cultivated to produce therapeutic proteins, vaccines, enzymes, or other biologically derived products. This phase encompasses all steps from the selection and genetic manipulation of the production organism to the cultivation of cells in bioreactors under tightly controlled environmental conditions.Host Selection and Genetic OptimizationThe... https://www.jove.com/v/40777 87 2026-03-12T20:57:34+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55300.jpg Using Synthetic Biology to Engineer Living Cells That Interface with Programmable Materials This paper presents a series of protocols for developing engineered cells and functionalized surfaces that enable synthetically engineered E. coli to control and manipulate programmable material surfaces. https://www.jove.com/v/55300 628 2017-03-09T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59655.jpg A Multilayer Microfluidic Platform for the Conduction of Prolonged Cell-Free Gene Expression The fabrication process of a PDMS-based, multilayer, microfluidic device that allows in vitro transcription and translation (IVTT) reactions to be performed over prolonged periods is described. Furthermore, a comprehensive overview of the hardware and software required to automate and maintain these reactions for prolonged durations is provided. https://www.jove.com/v/59655 683 2019-10-06T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60577.jpg Process Optimization using High Throughput Automated Micro-Bioreactors in Chinese Hamster Ovary Cell Cultivation Here, we present a detailed procedure to run a Design of Experiment in an automated micro-bioreactor followed by cell harvest and protein quantification using a Protein A column. https://www.jove.com/v/60577 568 2020-05-18T19:30:00+00:00 JoVE no https://visualize.jove.com/16185531-establishment-of-rat-model-of-transplantation-of-kidney-containing-adrenal-implants-and-its-protective-effects-on-the-transplanted-kidney monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/59403.jpg Orthotopic Rat Kidney Transplantation: A Novel and Simplified Surgical Approach The purpose of this manuscript and protocol is to explain and demonstrate in detail the surgical procedure of orthotopic kidney transplantation in rats. This method is simplified to achieve the correct perfusion of the donor kidney and shorten the reperfusion time by using the venous and ureteral cuff anastomosis technique. https://www.jove.com/v/59403 555 2019-05-07T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63464.jpg A Rat Orthotopic Renal Transplantation Model for Renal Allograft Rejection The rat orthotopic renal transplantation model contributes to investigating the mechanism of renal allograft rejection. The current model increases the recipients' survival without interference with blood supply and venous reflux of the lower body using an end-to-end anastomosis of kidney implantation and an end-to-side "tunnel" method of ureter-bladder anastomosis. https://www.jove.com/v/63464 419 2022-02-02T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68251.jpg Normothermic Machine Perfusion of Rat Kidneys for Transplantation This protocol describes the ex vivo normothermic machine perfusion of a rat kidney for subsequent transplantation into a recipient rat. https://www.jove.com/v/68251 642 2026-01-27T21:15:00+00:00 JoVE no https://visualize.jove.com/16237858-possession-use-and-transfer-of-select-agents-and-toxins-reconstructed-replication-competent-forms-of-the-1918-pandemic-influenza-virus-containing-any-portion-of-the-coding-regions-of-all-eight-gene-segments-interim-final-rule monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10826.jpg Viral Recombination Cells are sometimes infected by more than one virus at once. When two viruses disassemble to expose their genomes for replication in the same cell, similar regions of their genomes can pair together and exchange sequences in a process called recombination. Alternatively, viruses with segmented genomes can swap segments in a process called reassortment. Viral Recombination Can Create New Diseases Some diseases can infect multiple species. For example, pigs can be infected by some human and... https://www.jove.com/v/10826 57 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11625.jpg Leaky Scanning During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R stands for... https://www.jove.com/v/11625 148 JoVE no https://cloudfront.jove.com/files/ftp_upload/19595/19595_article_thumb_19595.jpg Subviral Agents Subviral agents are infectious entities that resemble viruses but lack one or more viral components, such as a capsid or essential replication machinery. These agents include viroids, prions, and satellites, each possessing distinct structural and functional characteristics that influence their mode of infection and replication.Viroids are the simplest subviral agents, consisting of circular, single-stranded RNA molecules without a protein coat. They exclusively infect plants, relying entirely... https://www.jove.com/v/19595 89 2025-06-12T16:31:04+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40845/40845_article_thumb_40845.jpg Influenza Influenza is an acute, highly communicable viral disease that affects the respiratory tract and is responsible for seasonal epidemics worldwide. Influenza A is the most prevalent type associated with widespread outbreaks and is subtyped based on two surface glycoproteins: hemagglutinin (H) and neuraminidase (N), as in H1N1. These glycoproteins are essential for viral infectivity, transmission, and immune recognition. Transmission occurs primarily through respiratory droplets and contaminated... https://www.jove.com/v/40845 87 2026-03-12T20:35:52+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40846/40846_article_thumb_40846.jpg Coronavirus Coronaviruses, including the severe acute respiratory syndrome coronavirus (SARS-CoV), are enveloped viruses characterized by their single-stranded, positive-sense RNA genome and helical nucleocapsid structure. The hallmark of these viruses is their club-shaped spike (S) glycoproteins that protrude from the viral envelope, facilitating attachment to host cells. Typically, coronaviruses infect the upper respiratory tract, often causing mild or asymptomatic disease. However, certain strains like... https://www.jove.com/v/40846 89 2026-05-20T21:16:22+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40863/40863_article_thumb_40863.jpg Inhibitors Of Virion Release Viral replication and dissemination rely on efficient mechanisms for host cell entry, genome replication, assembly, and release. Influenza viruses, such as types A and B, are negative-sense single-stranded RNA viruses with a segmented genome, that depend on two critical surface glycoproteins to carry out these processes: hemagglutinin (HA) and neuraminidase (NA). HA initiates infection by binding to sialic acid residues on the surface of host epithelial cells, facilitating receptor-mediated... https://www.jove.com/v/40863 85 2026-05-20T21:34:12+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59010.jpg Production of Pseudotyped Particles to Study Highly Pathogenic Coronaviruses in a Biosafety Level 2 Setting Here, we present a protocol to generate pseudotyped particles in a BSL-2 setting incorporating the spike protein of the highly pathogenic viruses Middle East respiratory syndrome and severe acute respiratory syndrome coronaviruses. These pseudotyped particles contain a luciferase reporter gene allowing quantification of virus entry into target host cells. https://www.jove.com/v/59010 520 2019-03-01T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60663.jpg Production of High-Titer Infectious Influenza Pseudotyped Particles with Envelope Glycoproteins from Highly Pathogenic H5N1 and Avian H7N9 Viruses This protocol describes an experimental process to produce high-titer infectious viral pseudotyped particles (pp) with envelope glycoproteins from two influenza A strains and how to determine their infectivity. This protocol is highly adaptable to develop pps of any other type of enveloped viruses with different envelope glycoproteins. https://www.jove.com/v/60663 490 2020-01-15T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/69062.jpg Modeling Dysplastic and Functional Lung Alveolar Repair after Influenza Infection This protocol provides instructions for intranasal administration of IAV and downstream analysis of mouse lung damage and associated transcriptional changes to lung cell types. https://www.jove.com/v/69062 465 2025-09-19T21:10:00+00:00 JoVE no https://visualize.jove.com/16272115-sex-differences-in-the-brain-implications-for-explaining-autism monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10981.jpg Sex-linked Disorders Like autosomes, sex chromosomes contain a variety of genes necessary for normal body function. When a mutation in one of these genes results in biological deficits, the disorder is considered sex-linked. Y chromosome mutations are called “Y-linked” and only affect males since they alone carry a copy of that chromosome. Mutations to the relatively small Y chromosome can impact male sexual function and secondary sex characteristics. Y-chromosome infertility is a disorder that affects sperm... https://www.jove.com/v/10981 103 2025-10-23T11:47:17+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10981.jpg Sex Linked Disorders Like autosomes, sex chromosomes contain a variety of genes necessary for normal body function. When a mutation in one of these genes results in biological deficits, the disorder is considered sex-linked. Y chromosome mutations are called “Y-linked” and only affect males since they alone carry a copy of that chromosome. Mutations to the relatively small Y chromosome can impact male sexual function and secondary sex characteristics. Y-chromosome infertility is a disorder that affects sperm... https://www.jove.com/v/11982 103 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18576.jpg Socioemotional Experience and Gender Development Social-emotional experiences and cultural influences play significant roles in shaping gender development. During middle childhood, from ages 6 to 11, peer groups become dominant in reinforcing gender norms. Children in this age group often align with same-gender peer groups, which actively encourage behaviors that conform to traditional gender roles. For instance, boys may be discouraged from engaging in activities perceived as feminine, reinforcing culturally dictated norms about masculinity... https://www.jove.com/v/18576 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18604.jpg Panic Disorder Panic disorder is an anxiety disorder characterized by recurrent and sudden minutes-long episodes of intense fear, known as panic attacks. These attacks may feel like heart attacks and often happen without warning or a specific cause. They can include symptoms such as rapid heart rate, shortness of breath, chest pain, trembling, sweating, dizziness, and a sense of helplessness. During a panic attack, individuals may feel as though they are experiencing a heart attack or are in a... https://www.jove.com/v/18604 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/19610.jpg Autism Spectrum Disorder Autism spectrum disorder (ASD) is a neurodevelopmental condition marked by persistent deficits in social communication and interaction alongside restrictive and repetitive behaviors or interests. ASD is sometimes accompanied by intellectual impairment. These core symptoms manifest differently among individuals, ranging from mild to severe. The disorder's complexity extends beyond its clinical presentation, encompassing a diverse range of biological, cognitive, and sociocultural influences.<br... https://www.jove.com/v/19610 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/19613.jpg Conduct Disorder Conduct disorder is a complex mental health diagnosis characterized by a repetitive and persistent pattern of behavior that violates societal norms, the rights of others, or age-appropriate rules. The diagnostic criteria for conduct disorder require the presence of at least three problematic behaviors within the past 12 months, with at least one occurring in the past six months. These behaviors are grouped into four categories: aggression toward people and animals; destruction of property;... https://www.jove.com/v/19613 88 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50758.jpg Sex Stratified Neuronal Cultures to Study Ischemic Cell Death Pathways Primary disassociated embryonic hippocampal neuronal cultures are useful for investigating the signaling mechanisms involved in neuron death. Sexing the embryos before the isolation and dissociation of the hippocampus allows the preparation of separate male and female cultures, which enables the researcher to identify and investigate sex-specific cell signaling. https://www.jove.com/v/50758 644 2013-12-09T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52202.jpg Protocol for Studying Extinction of Conditioned Fear in Naturally Cycling Female Rats Gonadal hormones such as estrogen modulate memory formation in a number of experimental paradigms including fear extinction memory. This protocol describes a set of methods for investigating the influence of gonadal hormones specifically during extinction in naturally cycling females, including estrous cycle monitoring and exogenous estrogen administration. https://www.jove.com/v/52202 547 2015-02-23T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66552.jpg Biomarker Identification for Gender Specificity of Alzheimer's Disease Based on the Glial Transcriptome Profiles This study analyzed single-nuclei transcriptomes of thirty-three individuals with Alzheimer's disease (AD), revealing sex-specific DEGs in glial cells. Functional enrichment analysis highlighted synaptic, neural, and hormone-related pathways. Key genes, namely NLGN4Y and its regulators, were identified, and potential therapeutic candidates for gender-specific AD were proposed. https://www.jove.com/v/66552 262 2024-05-20T15:00:00+00:00 JoVE no https://visualize.jove.com/16298340-characterization-of-a-human-swi2snf2-like-protein-hino80-demonstration-of-catalytic-and-dna-binding-activity monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12223.jpg Single-Strand DNA Binding Proteins For successful DNA replication, the unwinding of double-stranded DNA must be accompanied by stabilization and protection of the separated single strands of the DNA. This crucial task is performed by single-strand DNA-binding (SSB) proteins. They bind to the DNA in a sequence-independent manner, which means that the nitrogenous bases of the DNA need not be present in a specific order for binding of SSB proteins to it. The binding of SSB proteins straightens single-stranded DNA (ssDNA) and makes... https://www.jove.com/v/12223 63 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59073.jpg Real-time Observation of the DNA Strand Exchange Reaction Mediated by Rad51 Fluorescence resonance energy transfer-based real-time observation systems of the DNA strand exchange reaction mediated by Rad51 were developed. Using the protocols presented here, we are able to detect the formation of reaction intermediates and their conversion into products, while also analyzing the enzymatic kinetics of the reaction. https://www.jove.com/v/59073 384 2019-02-13T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59830.jpg In Vitro Biochemical Assays using Biotin Labels to Study Protein-Nucleic Acid Interactions Presented here are protocols for in vitro biochemical assays using biotin labels that may be widely applicable for studying protein-nucleic acid interactions. https://www.jove.com/v/59830 494 2019-07-17T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63147.jpg CD Spectroscopy to Study DNA-Protein Interactions The interaction of an ATP-dependent chromatin remodeler with a DNA ligand is described using CD spectroscopy. The induced conformational changes on a gene promoter analyzed by the peaks generated can be used to understand the mechanism of transcriptional regulation. https://www.jove.com/v/63147 408 2022-02-10T22:00:00+00:00 JoVE no https://visualize.jove.com/16299644-ivf-and-icsi-in-male-infertility-update-on-outcomes-risks-and-costs monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10768.jpg Meiosis II Meiosis II is the second and final stage of meiosis. It relies on the haploid cells produced during meiosis I, each of which contain only 23 chromosomes—one from each homologous initial pair. Importantly, each chromosome in these cells is composed of two joined copies, and when these cells enter meiosis II, the goal is to separate such sister chromatids using the same microtubule-based network employed in other division processes. The result of meiosis II is two haploid cells, each containing... https://www.jove.com/v/10768 117 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16314.jpg In Vitro Fertilization In vitro fertilization (IVF) is a form of assisted reproductive technology where an egg is fertilized with sperm in a controlled laboratory environment before transferring the resulting embryo into the uterus. This process is designed to help individuals and couples experiencing difficulties conceiving. The IVF process begins with ovarian stimulation, during which reproductive endocrinologists prescribe hormonal medications to stimulate the ovaries to produce multiple eggs instead of the single... https://www.jove.com/v/16314 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16317.jpg Infertility in Males Male infertility affects millions of couples worldwide, arising from various factors that impact different stages of the reproductive process. An endocrine imbalance resulting from conditions like hypogonadism, Klinefelter syndrome, or pituitary disorders can disrupt hormone levels and reduce sperm production. Testicular defects, such as tumors, cryptorchidism, atrophic testes, abnormal sperm morphology, and low sperm count or motility, may arise due to genetic factors, structural... https://www.jove.com/v/16317 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16318.jpg Infertility in Females Female infertility is defined as the inability to conceive after a year of regular, unprotected intercourse and affects about 10–15% of couples worldwide. The primary cause of female infertility is ovulatory disorders, which hinder the release of eggs. These disorders can be classified as hypothalamic amenorrhea, polycystic ovarian syndrome (PCOS), premature ovarian failure, and hyperprolactinemic anovulation disorders. Endometriosis, a condition characterized by abnormal growth of endometrial... https://www.jove.com/v/16318 88 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61647.jpg OP-IVM: Combining In vitro Maturation after Oocyte Retrieval with Gynecological Surgery In vitro maturation (IVM) before gynecological operation (OP-IVM) combines IVM following oocyte retrieval with routine gynecological surgery and serves as an extension of conventional IVM applications for fertility preservation. https://www.jove.com/v/61647 331 2021-05-09T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61963.jpg Fertility Preservation Through Oocyte Vitrification: Clinical and Laboratory Perspectives Oocyte cryopreservation is recognized by several international scientific societies as the gold standard for fertility preservation in postpubertal women. Appropriate clinical and laboratory strategies ensure maximum efficacy, efficiency, and safety of fertility preservation treatments. https://www.jove.com/v/61963 526 2021-09-16T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66212.jpg Monitoring Blood Glucose in Mouse Offspring After Intracytoplasmic Sperm Injection Here, we present a protocol to establish an intracytoplasmic sperm injection (ICSI)-embryo transfer (ET) mouse model, allowing us to observe age-related changes in glucose metabolism that may be attributed to ICSI, providing insights into its potential long-term impacts on human development. https://www.jove.com/v/66212 371 2024-05-17T20:40:00+00:00 JoVE no https://visualize.jove.com/16339314-topology-of-biological-networks-and-reliability-of-information-processing monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11032.jpg Reliability and Validity Reliability and validity are two important considerations that must be made with any type of data collection. Reliability refers to the ability to consistently produce a given result. In the context of psychological research, this would mean that any instruments or tools used to collect data do so in consistent, reproducible ways. Unfortunately, being consistent in measurement does not necessarily mean that you have measured something correctly. To illustrate this concept, consider a kitchen... https://www.jove.com/v/11032 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11511.jpg Protein-protein Interfaces Many proteins form complexes to carry out their functions, making protein-protein interactions (PPIs) essential for an organism's survival. Most PPIs are stabilized by numerous weak noncovalent chemical forces. The physical shape of the interfaces determines the way two proteins interact. Many globular proteins have closely-matching shapes on their surfaces, which form a large number of weak bonds. Additionally, many PPIs occur between two helices or between a surface cleft and a polypeptide... https://www.jove.com/v/11511 124 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11525.jpg Protein Networks An organism can have thousands of different proteins, and these proteins must cooperate to ensure the health of an organism. Proteins bind to other proteins and form complexes to carry out their functions. Many proteins interact with multiple other proteins creating a complex network of protein interactions. These interactions can be represented through maps depicting protein-protein interaction networks, represented as nodes and edges. Nodes are circles that are representative of a protein,... https://www.jove.com/v/11525 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12131.jpg Protein Folding Quality Check in the RER ER is the primary site for the maturation and folding of soluble and transmembrane secretory proteins. The calnexin cycle is a specific chaperone system that folds and assesses the confirmation of N-glycosylated proteins before they can exit the ER lumen. The primary players of this quality check pipeline are the lectins, ER-resident chaperones, and a glucosyl transferase enzyme. In case the calnexin system in the lumen fails to salvage a misfolded protein, it is transported to the cytoplasm... https://www.jove.com/v/12131 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11525.jpg Protein Networks An organism can have thousands of different proteins, and these proteins must cooperate to ensure the health of an organism. Proteins bind to other proteins and form complexes to carry out their functions. Many proteins interact with multiple other proteins creating a complex network of protein interactions. These interactions can be represented through maps depicting protein-protein interaction networks, represented as nodes and edges. Nodes are circles that are representative of a protein,... https://www.jove.com/v/12507 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15067.jpg Circuit Terminology An electrical network is a system composed of interconnected elements, such as resistors, capacitors, inductors, and voltage or current sources. Unlike a circuit, an electrical network does not necessarily form a closed path. In other words, while all circuits can be considered networks due to their interconnected nature, not every network qualifies as a circuit. A circuit, on the other hand, is also an interconnected system of electrical elements but must contain one or more closed paths. https://www.jove.com/v/15067 74 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62205.jpg Divergence of Root Microbiota in Different Habitats based on Weighted Correlation Networks Network analysis was applied to evaluate the association of various ecological microbial communities, such as soil, water and rhizosphere. Presented here is a protocol on how to use the WGCNA algorithm to analyze different co-occurrence networks that may occur in the microbial communities due to different ecological environments. https://www.jove.com/v/62205 589 2021-09-25T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62796.jpg JUMPn: A Streamlined Application for Protein Co-Expression Clustering and Network Analysis in Proteomics We present a systems biology tool JUMPn to perform and visualize network analysis for quantitative proteomics data, with a detailed protocol including data pre-processing, co-expression clustering, pathway enrichment, and protein-protein interaction network analysis. https://www.jove.com/v/62796 448 2021-10-19T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65150.jpg Modeling the Functional Network for Spatial Navigation in the Human Brain This paper presents an integrative approach to investigating the functional network for spatial navigation in the human brain. This approach incorporates a large-scale neuroimaging meta-analytic database, resting-state functional magnetic resonance imaging, and network modeling and graph-theoretical techniques. https://www.jove.com/v/65150 355 2023-10-13T20:20:00+00:00 JoVE no https://visualize.jove.com/16357376-computer-aided-detection-as-evidence-in-the-courtroom-potential-implications-of-an-appellate-courts-ruling monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11022.jpg Archival Research Some researchers gain access to large amounts of data without interacting with a single research participant. Instead, they use existing records to answer various research questions. This type of research approach is known as archival research. Archival research relies on looking at past records or data sets to look for interesting patterns or relationships. For example, a researcher might access the academic records of all individuals who enrolled in college within the past ten years and... https://www.jove.com/v/11022 100 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13539.jpg Data Validation Data validation is an essential part of a comprehensive assessment. Validation is confirming or verifying and opening the door to gathering more assessment data as it clarifies vague or unclear data. The process of checking and verifying the collected information is called data validation. The primary purpose of data validation is to ensure data is as free from error, bias, and misinterpretation as possible. Nursing assessment guides are generally based on holistic models rather than medical... https://www.jove.com/v/13539 63 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14577.jpg Effects of EDTA on End-Point Detection Methods Different methods, such as visual observance of metal-ion indicators, spectroscopic techniques, and potentiometric methods, can determine the endpoint of an EDTA titration. In the visual method, metal-ion indicators (metallochromic dyes), which have distinct colors in their free and complex forms, are added to the mixture to signal the titration's end point. They form stable complexes with metal ions, but these complexes are weaker than the corresponding metal–EDTA complexes. As a result, EDTA... https://www.jove.com/v/14577 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18184.jpg Eyewitness Memory Eyewitness memory refers to the recollection of events by someone who has directly witnessed them, often serving as critical evidence in legal settings. This type of memory is commonly used in criminal cases where a witness describes details like a suspect's appearance, clothing, or behavior during a crime. However, despite its perceived reliability, eyewitness memory is prone to significant errors. One such error is memory distortion, which occurs because human memory does not function like a... https://www.jove.com/v/18184 82 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52612.jpg Enhanced Genetic Analysis of Single Human Bioparticles Recovered by Simplified Micromanipulation from Forensic ‘Touch DNA’ Evidence Here we describe an optimized and efficient removal strategy for the collection of bio-particles present in ‘touch DNA’ samples, together with an enhanced amplification protocol involving a one-step 5 µl micro-volume lysis/STR amplification, to permit the recovery of short tandem repeat (STR) profiles of the bio-particle donor(s). https://www.jove.com/v/52612 709 2015-03-09T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53298.jpg Holistic Facial Composite Creation and Subsequent Video Line-up Eyewitness Identification Paradigm This applied experimental paradigm replicates circumstances by which an eyewitness to a real crime may create a holistic facial composite of the culprit from memory, and then attempt to identify the culprit from a video line-up containing the culprit or one in which he or she is not present. https://www.jove.com/v/53298 589 2015-12-24T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53773.jpg An Experimental Analysis of Children's Ability to Provide a False Report about a Crime The current methodology is designed to provide an ecologically relevant approach for measuring the veracity, length and quality of children's true and false testimonies. Implications of the current methodology for future research and professionals who interview children will also be discussed. https://www.jove.com/v/53773 456 2016-05-03T17:00:00+00:00 JoVE no https://visualize.jove.com/16376192-amplatzer-vascular-plug-to-occlude-the-internal-iliac-arteries-in-patients-undergoing-aortoiliac-aneurysm-repair monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15255.jpg Formation of the Platelet Plug The platelet phase, the second stage of hemostasis, commences around 15-20 seconds after an injury. It follows and overlaps with the vascular phase, during which blood vessels constrict to minimize blood loss. As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets... https://www.jove.com/v/15255 82 JoVE no https://cloudfront.jove.com/files/ftp_upload/17976/17976_article_thumb_17976.jpg Peripheral Artery Disease III: Interprofessional Care Peripheral Artery Disease (PAD) is characterized by narrowed arteries that diminish blood flow to the extremities. Effective management of PAD requires an interprofessional approach involving various healthcare professionals. The critical aspects of interprofessional care for PAD patients focus on risk factor modification, drug therapy, exercise therapy, nutrition therapy, critical limb ischemia care, and interventional radiology and surgical procedures.The primary treatment goal for PAD... https://www.jove.com/v/17976 87 2025-06-19T16:18:24+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17981/17981_article_thumb_17981.jpg Aneurysm III: Interprofessional Care Aneurysm management involves either conservative medical therapy or surgical intervention, depending on the size and symptoms of the aneurysm. Conservative management is generally reserved for smaller, asymptomatic aneurysms, while larger or symptomatic aneurysms often necessitate surgical repair.Conservative Medical TherapyFor small, asymptomatic aneurysms, particularly abdominal aortic aneurysms (AAA) less than 5.5 centimeters in diameter, conservative medical therapy is recommended. This... https://www.jove.com/v/17981 86 2025-06-19T16:19:25+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55253.jpg Patch Angioplasty in the Rat Aorta or Inferior Vena Cava We have established a model of pericardial patch angioplasty that can be used in either small-diameter veins or arteries. This model can be used to compare venous and arterial neointimal hyperplasia formation. https://www.jove.com/v/55253 364 2017-02-27T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64956.jpg Reduction of Radiation Exposure during Endovascular Treatment of Peripheral Arterial Disease Combining Fiber Optic RealShape Technology and Intravascular Ultrasound Described here is a stepwise method of combining Fiber Optic RealShape technology and intravascular ultrasound to show the potential of merging both techniques, in view of the reduction of radiation exposure and improvement of navigation tasks and treatment success during an endovascular procedure for the treatment of peripheral arterial disease. https://www.jove.com/v/64956 828 2023-04-21T19:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68211.jpg Modified Octopus Technique for Thoracoabdominal Aortic Aneurysm This study describes a modified octopus technique for endovascular treatment of thoracoabdominal aortic aneurysms, demonstrating favorable clinical outcomes. https://www.jove.com/v/68211 296 2025-08-01T19:50:00+00:00 JoVE no https://visualize.jove.com/16379373-an-intelligent-remote-monitoring-system-for-artificial-heart monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3750.jpg A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation Dual-chamber implantable cardioverter-defibrillators (ICDs) may improve detection of atrial fibrillation as well as differentiation of tachycardias. However, this advantage is undermined by complications associated with the second electrode, which is required in conventional dual chamber devices. Therefore, BIOTRONIK has developed a new electrode called the LinoxSMART S DX that, when used in conjunction with the Lumax DX ICD, offers dual-chamber detection without the risks associated with the... https://www.jove.com/v/3750 1000 2012-02-28T22:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13286.jpg Pulse rhythm Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding. Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle... https://www.jove.com/v/13286 90 JoVE no https://cloudfront.jove.com/files/ftp_upload/17887/17887_article_thumb_17887.jpg Holter Monitor: 24-Hour Monitoring Holter monitoring is a continuous electrocardiography (ECG) recording that tracks the heart's electrical activity over an extended period, generally 24 to 48 hours. This noninvasive diagnostic tool detects irregular heart rhythms that may not be captured during a standard ECG performed in a clinical setting.DeviceThe Holter monitor is a portable, small device connected to several electrodes on the patient's chest. These electrodes detect the heart's electrical signals and transmit them to the... https://www.jove.com/v/17887 83 2025-06-19T16:09:27+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52809.jpg Development of an Algorithm to Perform a Comprehensive Study of Autonomic Dysreflexia in Animals with High Spinal Cord Injury Using a Telemetry Device The catheter of a telemetry device is implanted into the abdominal aorta in order to continuously collect beat-by-beat hemodynamic data from animals pre and post-high thoracic spinal cord transection. A novel JAVA software was employed to analyze hemodynamic parameters as well as frequency and intensity of spontaneous episodes of autonomic dysreflexia. https://www.jove.com/v/52809 411 2016-07-29T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59019.jpg A Novel Digital Platform for a Monitored Home-based Cardiac Rehabilitation Program The aim is to promote a new approach to cardiac rehabilitation (CR), using a unique remote patient monitoring system that will enable healthcare providers to monitor CR patients at home at low cost, with the intention of making CR services more accessible and improving compliance. The study is currently underway. https://www.jove.com/v/59019 264 2019-04-19T20:00:00+00:00 JoVE no https://visualize.jove.com/16417261-rnai-silencing-of-exogenous-and-endogenous-reporter-genes-using-a-macrocyclic-octaamine-as-a-compact-sirna-carrier-studies-on-the-nonsilenced-residual-activity monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10801.jpg MicroRNAs MicroRNA (miRNA) are short, regulatory RNA transcribed from introns—non-coding regions of a gene—or intergenic regions—stretches of DNA present between genes. Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA ends... https://www.jove.com/v/10801 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10804.jpg RNA Interference RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated. This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used... https://www.jove.com/v/10804 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10804.jpg RNA Interference RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated. This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used... https://www.jove.com/v/11627 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11629.jpg siRNA - Small Interfering RNAs Small interfering RNAs, or siRNAs, are short regulatory RNA molecules that can silence genes post-transcriptionally, as well as the transcriptional level in some cases. siRNAs are important for protecting cells against viral infections and silencing transposable genetic elements. In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the ATP-dependent... https://www.jove.com/v/11629 150 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12033.jpg Experimental RNAi RNA interference (RNAi) is a cellular mechanism that inhibits gene expression by suppressing its transcription or activating the RNA degradation process. The mechanism was discovered by Andrew Fire and Craig Mello in 1998 in plants. Today, it is observed in almost all eukaryotes, including protozoa, flies, nematodes, insects, parasites, and mammals. This precise cellular mechanism of gene silencing has been developed into a technique that provides an efficient way to identify and determine the... https://www.jove.com/v/12033 135 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13151.jpg MicroRNAs MicroRNA (miRNA) are short, regulatory RNA transcribed from introns (non-coding regions of a gene) or intergenic regions (stretches of DNA present between genes). Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself, forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA... https://www.jove.com/v/13151 82 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51306.jpg Using RNA-interference to Investigate the Innate Immune Response in Mouse Macrophages In this protocol, we describe methods to efficiently transfect murine macrophage cell lines with siRNAs using the Amaxa Nucleofector 96-well Shuttle System, stimulate the macrophages with lipopolysaccharide, and monitor the effects on inflammatory cytokine production. https://www.jove.com/v/51306 767 2014-11-03T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55803.jpg Predicting Gene Silencing Through the Spatiotemporal Control of siRNA Release from Photo-responsive Polymeric Nanocarriers We present a novel method that uses photo-responsive block copolymers for more efficient spatiotemporal control of gene silencing with no detectable off-target effects. Additionally, changes in gene expression can be predicted using straightforward siRNA release assays and simple kinetic modeling. https://www.jove.com/v/55803 713 2017-07-21T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58660.jpg Polyethyleneimine-coated Iron Oxide Nanoparticles as a Vehicle for the Delivery of Small Interfering RNA to Macrophages In Vitro and In Vivo We describe a method of using polyethyleneimine (PEI)-coated superparamagnetic iron oxide nanoparticles for transfecting macrophages with siRNA. These nanoparticles can efficiently deliver siRNA to macrophages in vitro and in vivo and silence target gene expression. https://www.jove.com/v/58660 576 2019-02-05T21:00:00+00:00 JoVE no https://visualize.jove.com/16420689-memory-in-astrocytes-a-hypothesis monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10843.jpg Glial Cells Overview Glial cells are one of the two main types of cells in the nervous system. Glia cells comprise astrocytes, oligodendrocytes, microglia, and ependymal cells in the central nervous system, and satellite and Schwann cells in the peripheral nervous system. These cells do not communicate via electrical signals like neurons do, but they contribute to virtually every other aspect of nervous system function. In humans, the number of glial cells is roughly equal to the number of neurons in the... https://www.jove.com/v/10843 64 2025-10-23T18:49:28+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12175.jpg Neuron Structure Neurons are the main type of cell in the nervous system that generate and transmit electrochemical signals. They primarily communicate with each other using neurotransmitters at specific junctions called synapses. Neurons come in many shapes that often relate to their function, but most share three main structures: an axon and dendrites that extend out from a cell body. Structure and Function of Neurons The neuronal cell body—the soma— houses the nucleus and organelles vital to cellular... https://www.jove.com/v/12175 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14996.jpg Nervous Tissue: Glial Cells Glia, or neuroglia, are vital support cells that assist neurons in their functions. The term "glia" originates from the Greek word for "glue," reflecting their role in holding the nervous system together. These cells can be categorized into six types: four in the central nervous system (CNS) and two in the peripheral nervous system (PNS). The CNS glial cell includes the astrocytes, the oligodendrocytes, the microglia, and the ependymal cells. Astrocytes are star-shaped glial cells that interact... https://www.jove.com/v/14996 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18174.jpg Storage A schema is a mental framework that helps individuals organize and interpret information. Schemata, formed from previous experiences, influence how we process new information: how we encode it, the inferences we make, and how we retrieve it. For instance, a schema for what a typical classroom looks like might include desks, a teacher's desk, a whiteboard, and students in such an environment. This expectation helps us quickly understand and navigate new classrooms without needing to analyze each... https://www.jove.com/v/18174 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50079.jpg Isolation and Culture of Mouse Cortical Astrocytes Astrocytes have been recognized to be versatile cells participating in fundamental biological processes that are essential for normal brain development and function, and central nervous system repair. Here we present a rapid procedure to obtain pure mouse astrocyte cultures to study the biology of this major class of central nervous system cells. https://www.jove.com/v/50079 685 2013-01-19T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58116.jpg Analyzing the Size, Shape, and Directionality of Networks of Coupled Astrocytes Here we present a protocol to assess the organization of astrocytic networks. The described method minimizes bias to provide descriptive measures of these networks such as cell count, size, area, and position within a nucleus. Anisotropy is assessed with a vectorial analysis. https://www.jove.com/v/58116 610 2018-10-04T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63679.jpg Investigation of Spatial Interaction Between Astrocytes and Neurons in Cleared Brains Combining viral vector transduction and brain clearing using the CLARITY method allows the investigation of a large number of neurons and astrocytes simultaneously. https://www.jove.com/v/63679 317 2022-03-31T21:50:00+00:00 JoVE no https://visualize.jove.com/16453069-non-algorithmic-access-to-calendar-information-in-a-calendar-calculator-with-autism monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18627.jpg Modeling in Therapy Modeling, a key technique in therapy, uses observational learning to help clients acquire and practice new skills by watching therapists demonstrate desired behaviors. This approach, rooted in Albert Bandura's concept of vicarious learning, plays a significant role in therapeutic interventions for various psychological conditions, including social anxiety, ADHD, and depression. Participant Modeling Participant modeling involves therapists demonstrating calm and effective behaviors in situations... https://www.jove.com/v/18627 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/19610.jpg Autism Spectrum Disorder Autism spectrum disorder (ASD) is a neurodevelopmental condition marked by persistent deficits in social communication and interaction alongside restrictive and repetitive behaviors or interests. ASD is sometimes accompanied by intellectual impairment. These core symptoms manifest differently among individuals, ranging from mild to severe. The disorder's complexity extends beyond its clinical presentation, encompassing a diverse range of biological, cognitive, and sociocultural influences.<br... https://www.jove.com/v/19610 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/19615.jpg Learning Disabilities Learning disabilities are cognitive disorders caused by neurological impairments that affect cognitive functions like language and reading, without indicating overall intellectual or developmental challenges. These disabilities differ from global intellectual or developmental disabilities as they are limited to distinct cognitive functions. Common learning disabilities include dysgraphia, dyslexia, and dyscalculia, each of which impacts unique aspects of learning. Dyslexia Dyslexia is a... https://www.jove.com/v/19615 85 2025-08-04T17:44:39+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52677.jpg Testing Sensory and Multisensory Function in Children with Autism Spectrum Disorder We describe how to implement a battery of behavioral tasks to examine the processing and integration of sensory stimuli in children with ASD. The goal is to characterize individual differences in temporal processing of simple auditory and visual stimuli and relate these to higher order perceptual skills like speech perception. https://www.jove.com/v/52677 553 2015-04-22T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55941.jpg A Familiarization Protocol Facilitates the Participation of Children with ASD in Electrophysiological Research Electrophysiological research is an important tool for identifying biomarkers of developmental disorders, including Autism Spectrum Disorders (ASD), but data collection in these populations remains challenging. This work presents a familiarization protocol to accompany research that includes electroencephalography (EEG) to improve the likelihood of collecting EEG data from children with ASD. https://www.jove.com/v/55941 522 2017-07-31T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57217.jpg A Semantic Priming Event-related Potential (ERP) Task to Study Lexico-semantic and Visuo-semantic Processing in Autism Spectrum Disorder This paper describes a semantic priming ERP task using within-modality pairs of pictures and words to investigate semantic processing in individuals with autism spectrum disorder (ASD). https://www.jove.com/v/57217 497 2018-04-12T21:30:00+00:00 JoVE no https://visualize.jove.com/16461508-equipment-standards-for-interventional-cardiology monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17881.jpg Imaging Studies for Cardiovascular System I:Echocardiography Cardiac imaging studies encompass a wide range of noninvasive and minimally invasive techniques designed to visualize the heart's structure and function in detail. One such technique is echocardiography, which uses high-frequency ultrasound waves to produce detailed images of the heart, known as echocardiograms. Indications: Echocardiography is utilized to diagnose heart failure, valve disorders, and myocardial infarction. It also assesses cardiac structures' size, shape, and motion, evaluates... https://www.jove.com/v/17881 77 JoVE no https://cloudfront.jove.com/files/ftp_upload/17885/17885_article_thumb_17885.jpg Imaging Studies for Cardiovascular System V: CT Cardiac computed tomography (CT) scanning is an advanced cardiac imaging technique that utilizes CT technology, with or without intravenous (IV) contrast, to produce accurate cross-sectional virtual slices of specific areas of the heart, coronary circulation, and major blood vessels such as the aorta, pulmonary veins, and arteries. The computer processes these slices to generate three-dimensional images. Multidetector CT (MDCT) is a rapid form of CT scanning that captures multiple slices... https://www.jove.com/v/17885 88 2025-06-19T01:08:22+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17888/17888_article_thumb_17888.jpg Cardiac Catheterization I: Pre-Procedure Overview Cardiac catheterization is an invasive diagnostic technique used to identify and evaluate structural and functional diseases of the heart and major blood vessels. This technique diagnoses congenital heart disease, coronary artery disease, valvular heart disease, and coronary spasms and assesses ventricular function. It helps guide treatment decisions, including the need for revascularization procedures like percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) and... https://www.jove.com/v/17888 88 2025-06-19T01:14:01+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17889/17889_article_thumb_17889.jpg Cardiac Catheterization II: Right Heart Catheterization Right Heart Catheterization: An OverviewRight heart catheterization is an invasive diagnostic procedure that measures right-sided cardiac and pulmonary artery pressures, calculates cardiac output, and identifies intracardiac shunts. It provides detailed hemodynamic data essential for diagnosing and managing various cardiovascular conditions, such as pulmonary hypertension.Access SitesCommon access sites for right heart catheterization include the internal jugular vein in the neck region, the... https://www.jove.com/v/17889 81 2025-06-19T01:14:22+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17890/17890_article_thumb_17890.jpg Cardiac Catheterization III: Left Heart Catheterization Left heart catheterization is an invasive diagnostic procedure used to evaluate the function and structure of the left side of the heart. It is generally performed to diagnose and treat cardiovascular conditions such as valve abnormalities, coronary artery disease, and congenital heart defects.Diagnostic and therapeutic purposesLeft heart catheterization serves various diagnostic and therapeutic purposes, including:Assessing coronary artery bypass grafts.Evaluating coronary artery disease in... https://www.jove.com/v/17890 84 2026-01-28T05:01:00+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17891/17891_article_thumb_17891.jpg Cardiac Catheterization IV: Nursing Management Nursing responsibilities before cardiac catheterization include:Assess for allergies and establish baseline health status.Before cardiac catheterization, assess the patient for allergies to contrast dye. Perform a comprehensive baseline assessment, including vital signs, heart and breath sounds, and a neurovascular assessment of the extremities, noting distal pulses, skin color, and temperature. Instruct the patient to fast for 8-12 hours before the procedure. Evaluate baseline laboratory... https://www.jove.com/v/17891 86 2025-06-19T01:15:06+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52606.jpg Non-fluoroscopic Catheter Tracking for Fluoroscopy Reduction in Interventional Electrophysiology Radiation exposure is an underestimated risk in complex ablation procedures. Here, we describe a protocol to significantly decrease fluoroscopy time and dosage for both the patient and the lab staff by using a novel non-fluoroscopic catheter visualization system. https://www.jove.com/v/52606 646 2015-05-26T06:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62265.jpg Interventional Diagnostic Procedure: A Practical Guide for the Assessment of Coronary Vascular Function The purpose of this practical guide is to provide information on the preparation and administration of an interventional diagnostic procedure in clinical practice. It discusses some key preparation and safety considerations, as well as tips for procedural success. https://www.jove.com/v/62265 628 2022-03-15T07:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67473.jpg Catheter-based Endovascular Angioplasty for Fibrosing Mediastinitis-associated Pulmonary Vein Stenosis Pulmonary vein stenosis (PVS) is a life-threatening complication of fibrosing mediastinitis (FM), with a poor prognosis if not properly treated. Currently, catheter-based endovascular angioplasty is a promising therapeutic strategy for FM-associated PVS. This protocol primarily outlines a stepwise approach to the transcatheter procedure for FM-associated PVS. https://www.jove.com/v/67473 419 2025-08-26T05:00:00+00:00 JoVE no https://visualize.jove.com/16470476-the-current-role-of-abdominal-ultrasound-in-the-clinical-management-of-patients-with-aids monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13867.jpg Ultrasonography Ultrasonography is an imaging technique that uses high-frequency sound waves to visualize the body's internal structures. It is a non-invasive and safe procedure that does not involve the use of ionizing radiation, making it widely used in various medical fields. Ultrasonography is used to study heart function, blood flow in the neck or extremities, certain conditions such as gallbladder disease, and fetal growth and development. During an ultrasonography procedure, a handheld device called a... https://www.jove.com/v/13867 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16411.jpg Assessment of the Abdomen I: Inspection and Auscultation Introduction The abdominal examination is a cornerstone of clinical medicine, serving as a critical tool in diagnosing various gastrointestinal (GI) diseases. It involves a systematic approach that includes inspection and auscultation, each with distinct yet complementary roles in assessing the abdomen. This article will delve into these two primary methods healthcare professionals use to examine the abdomen. Inspection of the Abdomen The first step in any abdominal examination is inspection. https://www.jove.com/v/16411 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16429.jpg Peptic Ulcer Disease III: Clinical Manifestations and Diagnostic Studies Peptic ulcer disease (PUD) presents with diverse symptoms depending on the location and severity of the ulcer. Clinical manifestations of peptic ulcer include dull pain and a burning sensation in the mid-epigastric region. Few clinical manifestations differentiate gastric ulcers from duodenal ulcers. Distinctions in the location, timing, and pain relief are crucial for healthcare providers in differentiating between gastric and duodenal ulcers during clinical assessments. Location of Pain:... https://www.jove.com/v/16429 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16447.jpg Ultrasound II: Endoscopic Ultrasound and FibroScan Endoscopic Ultrasound (EUS) and FibroScan are valuable diagnostic tools in gastroenterology and hepatology, each with specific applications and techniques. Endoscopic Ultrasound (EUS): Technological Integration: EUS is a sophisticated integration of optical endoscopy and ultrasonography. The endoscope visualizes the mucosal surface directly, while the ultrasound component penetrates deeper to visualize organs and structures beyond the gastrointestinal wall. Image Formation: The ultrasound... https://www.jove.com/v/16447 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16462.jpg Ultrasound I: Abdominal Ultrasonography Introduction: Abdominal ultrasonography, commonly known as abdominal ultrasound, is a vital, non-invasive medical imaging technique widely used in healthcare. Procedure: This diagnostic tool allows the clinician to visually inspect internal structures within the abdomen, including vital organs such as the liver, gallbladder, pancreas, kidneys, and spleen. The abdominal ultrasound process begins with applying a special gel to the patient's skin over the abdomen. This gel enhances the... https://www.jove.com/v/16462 80 JoVE no https://cloudfront.jove.com/files/ftp_upload/18489/18489_article_thumb_18489.jpg Imaging Studies II: Ultrasonography IntroductionUltrasonography, or renal ultrasound, is a noninvasive medical imaging technique that uses high-frequency sound waves to visualize the kidneys, ureters, bladder, and surrounding tissues.Indications for Urinary System UltrasonographyUrinary system ultrasonography is indicated in various clinical scenarios, such as:Kidney Stones (Urolithiasis): To detect and monitor the size and presence of kidney or urinary tract stones.Hydronephrosis: To assess the dilation of the renal pelvis and... https://www.jove.com/v/18489 84 2025-06-19T16:29:30+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65431.jpg Measuring Diaphragm Thickness and Function Using Point-of-Care Ultrasound Diaphragm thickness and function can be assessed in healthy individuals and critically ill patients using point-of-care ultrasound. This technique offers an accurate, reproducible, feasible, and well-tolerated method for evaluating diaphragm structure and function. https://www.jove.com/v/65431 351 2023-11-03T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65487.jpg An Approach to Point-Of-Care Ultrasound Evaluation of the Abdominal Aorta This protocol reviews the steps to image the abdominal aorta with point-of-care ultrasound. We discuss image acquisition, troubleshooting imaging pitfalls and artifacts, and the recognition of life-threatening abdominal aortic pathology. https://www.jove.com/v/65487 432 2023-09-08T20:40:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68554.jpg The Application of Point-of-Care Ultrasonography (POCUS) in the Management of Acute Respiratory Distress Syndrome (ARDS) in the Intensive Care Unit Here, we present a protocol for bedside POCUS application in ARDS management within the ICU. It details standardized techniques for lung, cardiac, diaphragm, venous, and gastric assessments to guide ventilation, predict weaning, and prevent complications. https://www.jove.com/v/68554 502 2025-12-12T20:50:00+00:00 JoVE no https://visualize.jove.com/16480706-application-of-adaptive-neuro-fuzzy-inference-system-for-epileptic-seizure-detection-using-wavelet-feature-extraction monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15214.jpg Epilepsy and Seizures: Overview Epilepsy is a chronic neurological disease marked by recurrent, unpredictable seizures. These seizures are caused by abnormal electrical discharges in the brain, leading to behavior, sensation, or consciousness alterations. They can also cause transient impairment of awareness, interfering with daily activities. Various factors can trigger epilepsy, including genetic factors, brain damage, metabolic causes, and unknown etiology. Diagnosis of epilepsy involves electroencephalography (EEG), which... https://www.jove.com/v/15214 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54746.jpg Network Analysis of Foramen Ovale Electrode Recordings in Drug-resistant Temporal Lobe Epilepsy Patients This protocol describes a procedure to track the evolution of mesial network measures in temporal lobe epilepsy (TLE) patients. It is based on the combination of intracranial recordings with a novel numerical technique for data analysis. Specifically, we present a protocol for network analyses of foramen ovale recordings. https://www.jove.com/v/54746 572 2016-12-18T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54883.jpg Interictal High Frequency Oscillations Detected with Simultaneous Magnetoencephalography and Electroencephalography as Biomarker of Pediatric Epilepsy High Frequency Oscillations (HFOs) have emerged as presurgical biomarkers for the identification of the epileptogenic zone in pediatric patients with medically refractory epilepsy. A methodology for the noninvasive recording, detection, and localization of HFOs with simultaneous scalp electroencephalography (EEG) and magnetoencephalography (MEG) is presented. https://www.jove.com/v/54883 622 2016-12-06T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59637.jpg Use of a Wireless Video-EEG System to Monitor Epileptiform Discharges Following Lateral Fluid-Percussion Induced Traumatic Brain Injury Here we present a protocol to induce severe TBI with the lateral fluid percussion injury (FPI) model in adult, male Wistar rats. We also demonstrate the use of a wireless telemetry system to collect continuous video-EEG recordings and monitor for epileptiform discharges consistent with post-traumatic... https://www.jove.com/v/59637 556 2019-06-21T21:00:00+00:00 JoVE no https://visualize.jove.com/16481006-structural-basis-for-the-cooperative-assembly-of-large-t-antigen-on-the-origin-of-replication monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10789.jpg Replication in Eukaryotes Overview In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus. Many Proteins Orchestrate Replication at the Origin Eukaryotic replication follows many of the... https://www.jove.com/v/10789 151 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10789.jpg Replication in Eukaryotes Overview In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus. Many Proteins Orchestrate Replication at the Origin Eukaryotic replication follows many of the... https://www.jove.com/v/11546 151 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13195.jpg Replication in Prokaryotes DNA replication has three main steps: initiation, elongation, and termination. Replication in prokaryotes begins when initiator proteins bind to the single origin of replication (ori) on the cell's circular chromosome. Replication then proceeds around the entire circle of the chromosome in each direction from the two replication forks, resulting in two DNA molecules. Many Proteins Work Together to Replicate the Chromosome Replication is coordinated and carried out by a host of specialized... https://www.jove.com/v/13195 92 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13196.jpg Replication in Eukaryotes In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fulfill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus. Many Proteins Orchestrate Replication at the Origin Eukaryotic replication follows many of the same... https://www.jove.com/v/13196 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13196.jpg Replication in Eukaryotes In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fulfill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus. Many Proteins Orchestrate Replication at the Origin Eukaryotic replication follows many of the same... https://www.jove.com/v/13945 89 JoVE no https://cloudfront.jove.com/files/ftp_upload/19551/19551_article_thumb_19551.jpg Mechanism of Conjugation Bacterial conjugation is a mechanism of horizontal gene transfer that enables the exchange of genetic material between bacterial cells through direct contact. This process is facilitated by a donor cell carrying a conjugative plasmid, which encodes genes necessary for pilus formation, DNA replication, and transfer. The conjugative plasmid plays a central role in initiating and executing the transfer of genetic material.The tra region of the conjugative plasmid encodes proteins responsible for... https://www.jove.com/v/19551 79 2025-06-12T16:18:14+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55946.jpg Determination of the Optimal Chromosomal Location(s) for a DNA Element in Escherichia coli Using a Novel Transposon-mediated Approach Here, the power of a transposon-mediated random insertion of a non-coding DNA element was used to resolve its optimal chromosomal position. https://www.jove.com/v/55946 672 2017-09-11T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61993.jpg Rapid Assembly of Multi-Gene Constructs using Modular Golden Gate Cloning The goal of this protocol is to provide a detailed, step-by-step guide for assembling multi-gene constructs using the modular cloning system based on Golden Gate cloning. It also gives recommendations on critical steps to ensure optimal assembly based on our experiences. https://www.jove.com/v/61993 511 2021-02-05T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67076.jpg Hybrid Ensemble and Single-molecule Assay to Image the Motion of Fully Reconstituted CMG We report a hybrid ensemble and single-molecule assay to directly image and quantify the motion of fluorescently labeled, fully reconstituted Cdc45/Mcm2-7/GINS (CMG) helicase on linear DNA molecules held in place in an optical trap. https://www.jove.com/v/67076 611 2024-07-26T21:55:00+00:00 JoVE no https://visualize.jove.com/16491661-experience-in-the-use-of-the-new-artificial-lung-ventilation-apparatus-avenir-221p-for-treatment-of-children monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1421.jpg A Novel Rescue Technique for Difficult Intubation and Difficult Ventilation We describe a technique to maintain oxygenation and ventilation using an endotracheal tube inserted nasally to the level of the naso-pharynx while sealing the mouth and nares for successful positive pressure ventilation. https://www.jove.com/v/1421 286 2011-01-18T02:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16349.jpg Acute Respiratory Failure-I Acute respiratory failure is a condition characterized by the inability of the lungs to perform their primary function: gas exchange. This failure leads to insufficient oxygen levels (hypoxemia) in the blood, elevated carbon dioxide levels (hypercapnia), or both, causing critical impairment in organ function. Definition: It is defined by specific criteria based on blood gas measurements. Hypoxemia happens when the partial pressure of oxygen (PaO2) falls below 60 mmHg. At the same time,... https://www.jove.com/v/16349 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16350.jpg Acute Respiratory Failure-II Type I Respiratory Failure, or hypoxemic respiratory failure, occurs when the partial pressure of oxygen (PaO2) in arterial blood falls below 60 mmHg while breathing room air without a corresponding increase in arterial carbon dioxide levels (PaCO2). This condition highlights a significant impairment in the lungs' capacity to oxygenate the blood. The underlying physiological abnormalities that contribute to hypoxemic respiratory failure include: • Ventilation-Perfusion (V/Q) Mismatch: The... https://www.jove.com/v/16350 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16385.jpg Oxygen Delivering System II: Venturi Mask and Transtracheal Oxygen Oxygen therapy is a pivotal aspect of medical care, particularly for patients with respiratory ailments. Two prominent oxygen-delivering systems include the Venturi mask and the transtracheal oxygen catheter. Venturi Mask The Venturi mask, named after the Venturi effect, is designed to deliver precise oxygen concentrations. It consists of a large tube with an oxygen inlet that narrows down, causing a pressure drop that pulls air in through adjustable side ports. The mask is a lightweight,... https://www.jove.com/v/16385 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16399.jpg Mechanical Ventilation II: Invasive Ventilation Ventilators are essential medical equipment used to aid patients with respiratory difficulties. Their primary function is to assist or replace spontaneous breathing by providing mechanical ventilation. There are two general classes of mechanical ventilators: negative-pressure and positive-pressure ventilators. Negative-Pressure Ventilators Negative-pressure ventilators create a vacuum around the chest or body to draw air into the lungs, simulating breathing. This method does not require an... https://www.jove.com/v/16399 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16400.jpg Mechanical Ventilation III: Noninvasive Ventilation Noninvasive positive-pressure ventilation (NIPPV), continuous positive airway pressure (CPAP), and bilevel positive airway pressure (BiPAP) are essential methods in respiratory care. These ventilation techniques offer unique benefits for patients with various respiratory conditions, providing adequate support without requiring intubation. Let's explore how each method is crucial in improving patient outcomes and enhancing respiratory therapy. Noninvasive Positive-Pressure Ventilation (NIPPV)<br... https://www.jove.com/v/16400 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16401.jpg Ventilatory Modes Mechanical ventilators are life-saving devices that support or replace spontaneous breathing. They deliver breaths to patients through varying methods known as ventilator modes. Understanding these modes is critical for healthcare providers managing patients with respiratory failure. There are three ventilatory modes: full support, partial support, and spontaneous. These are described below. Full Support Modes Full support modes include controlled mechanical ventilation, continuous mandatory... https://www.jove.com/v/16401 74 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62982.jpg Normothermic Negative Pressure Ventilation Ex Situ Lung Perfusion: Evaluation of Lung Function and Metabolism This paper describes a porcine model of negative pressure ventilation ex situ lung perfusion, including procurement, attachment, and management on the custom-made platform. Focus is made on anesthetic and surgical techniques, as well as troubleshooting. https://www.jove.com/v/62982 571 2022-02-14T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64706.jpg Laryngeal Mask Airway (LMA) Placement in a Neonatal Patient Simulator Using a Non-Inflatable Supraglottic Airway (SGA) This protocol is designed to describe a method to place and establish a supraglottic (alternative) airway during neonatal resuscitation. It can be used in situations where frontline providers cannot ventilate or endotracheally intubate neonates requiring resuscitation. https://www.jove.com/v/64706 296 2023-07-14T21:10:00+00:00 JoVE no https://visualize.jove.com/16492827-intravenous-anesthetics-are-more-effective-than-volatile-anesthetics-on-inhibitory-pathways-in-rat-hippocampal-ca1 monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14497.jpg Local Anesthetics: Mechanism of Action Local anesthetics (LAs) block sensory and motor impulses by inhibiting the sodium channels on the nerve cell membranes. This induces temporary loss of sensation, relieving pain in a specific body area. Local anesthetics are amphiphilic molecules consisting of a hydrophobic aromatic part linked to a hydrophilic group by an ester or amide linkage. They are weak bases and are usually available as salts, which increases their solubility and stability. Once administered, LAs exist in the body either... https://www.jove.com/v/14497 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14498.jpg Local Anesthetics: Pharmacokinetics The potency and duration of action of local anesthetics (LAs) are determined by their pharmacokinetics. Pharmacokinetics describes how LAs are absorbed, distributed, metabolized, and eliminated from the body. When administered to the vascular tissues, LAs are quickly absorbed and enter the systemic circulation, reducing their localized effects. Adding vasoconstrictors such as epinephrine to LAs reduces their absorption into the systemic circulation, making them clinically effective. The... https://www.jove.com/v/14498 73 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14503.jpg Local Anesthetics: Clinical Application as Spinal Anesthesia Spinal anesthetics are given during lower abdomen and limb surgeries to block sensory and motor neurons. They are administered in the mid to low lumbar regions, primarily acting on the cauda equina's nerve roots. The blockade level depends on the local anesthetic (LA) concentration. Usually, low LA concentrations are sufficient to block sensory fibers, while only high LA concentrations block motor fibers. Other factors like injection volume and speed, the patient's posture, and the drug... https://www.jove.com/v/14503 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14749.jpg Local Anesthetics: Clinical Application as Intravenous Regional Anesthesia Intravenous regional anesthesia or the Bier block technique is used to anesthetize a specific limb or extremity. It uses exsanguinated or blood-drained vessels to transport local anesthetics or LAs to the peripheral nerve trunks. Lidocaine without vasoconstrictors like epinephrine is most commonly used for this technique. Other drugs used are prilocaine, ropivacaine, and chloroprocaine. Bupivacaine is not recommended for this technique due to its high cardiac toxicity. One of the advantages of... https://www.jove.com/v/14749 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15190.jpg Parenteral Anesthetics: Overview Intravenous anesthetics are drugs administered parenterally to induce anesthesia or sedation. Propofol is a widely used agent formulated as a 1% emulsion in soybean oil, glycerol, and egg phosphatide. It induces rapid anesthesia primarily due to its rapid distribution from the bloodstream to target tissues and is metabolized in the liver. However, it can cause significant pain on injection and hypertriglyceridemia. Fospropofol, a water-based prodrug of propofol, lacks these adverse effects. https://www.jove.com/v/15190 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15191.jpg Inhalational Anesthetics: Overview Inhalation anesthetics are drugs that induce general anesthesia upon inhalation. They work by increasing the sensitivity of GABAA receptors or inhibiting NMDA receptors, leading to a decrease in central nervous system activity. The depth of anesthesia can be rapidly adjusted by changing the concentration of the inhaled gas. Some common examples of inhalational anesthetics include volatile liquids like isoflurane, desflurane, sevoflurane and gases like xenon and nitrous oxide. Isoflurane, a... https://www.jove.com/v/15191 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51079.jpg Assessing Changes in Volatile General Anesthetic Sensitivity of Mice after Local or Systemic Pharmacological Intervention Loss of the righting reflex has long served as a standard behavioral surrogate for unconsciousness, also called hypnosis, in laboratory animals. Alterations in volatile anesthetic sensitivity caused by pharmacological interventions can be detected with a carefully controlled high-throughput assessment system, which may be adapted for delivery of any inhaled therapeutic. https://www.jove.com/v/51079 529 2013-10-17T04:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55940.jpg Acute In Vivo Electrophysiological Recordings of Local Field Potentials and Multi-unit Activity from the Hyperdirect Pathway in Anesthetized Rats In this study, the methodology is presented on how to perform multi-site in vivo electrophysiological recordings from the hyperdirect pathway under urethane anesthesia. https://www.jove.com/v/55940 646 2017-06-22T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61333.jpg Optogenetic Activation of Afferent Pathways in Brain Slices and Modulation of Responses by Volatile Anesthetics Ex vivo brain slices can be used to study the effects of volatile anesthetics on evoked responses to afferent inputs. Optogenetics are employed to independently activate thalamocortical and corticocortical afferents to non-primary neocortex, and synaptic and network responses are modulated with isoflurane. https://www.jove.com/v/61333 496 2020-07-23T22:00:00+00:00 JoVE no https://visualize.jove.com/16508805-applying-integrated-urban-water-management-concepts-a-review-of-australian-experience monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4009.jpg Spatial Multiobjective Optimization of Agricultural Conservation Practices using a SWAT Model and an Evolutionary Algorithm This work demonstrates an integration of a water quality model with an optimization component utilizing evolutionary algorithms to solve for optimal (lowest-cost) placement of agricultural conservation practices for a specified set of water quality improvement objectives. The solutions are generated using a multi-objective approach, allowing for explicit quantification of tradeoffs. https://www.jove.com/v/4009 713 2012-12-10T01:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11100.jpg Adaptations that Reduce Water Loss Though evaporation from plant leaves drives transpiration, it also results in loss of water. Because water is critical for photosynthetic reactions and other cellular processes, evolutionary pressures on plants in different environments have driven the acquisition of adaptations that reduce water loss. In land plants, the uppermost cell layer of a plant leaf, called the epidermis, is coated with a waxy substance called the cuticle. This hydrophobic layer is composed of the polymer cutin and... https://www.jove.com/v/11100 117 2025-10-23T18:48:38+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16875.jpg Quality of Water In concrete preparation, the quality of water is paramount as it affects the strength and durability of the concrete. Potable water is usually preferred; however, it must not have excessive sodium or potassium to prevent compromising the concrete's integrity. Water quality is typically evaluated based on impurities such as dissolved solids, chlorides, and sulfates, and its pH value is ideally between 6 and 8. Even slightly acidic natural water may be acceptable unless it contains harmful... https://www.jove.com/v/16875 79 JoVE no https://cloudfront.jove.com/files/ftp_upload/18102/18102_article_thumb_18102.jpg Design Example: Design of an Irrigation Channel Trapezoidal channels are widely used in irrigation systems due to their cost-effectiveness and efficiency in conveying water. Trapezoidal channels feature a flat bottom and sloping sides, making them stable and easier to construct compared to other shapes. The bottom width and side slope ratio are determined based on the required flow capacity and site conditions. The side slope is kept gentle for unlined channels to prevent soil erosion.Hydraulic parameters in channel design include the flow... https://www.jove.com/v/18102 87 2025-03-26T22:04:50+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18117/18117_article_thumb_18117.jpg Design Example: Analyzing Capacity Contours for Flood Risk Assessment Flood risk assessment involves careful planning and analysis to ensure the safety of communities near water retention structures. Capacity contours are a vital tool in this process, as they illustrate the potential spread of water at specific levels in a given area. In the context of building a bund across a small valley, these contours play a critical role in evaluating the safety of nearby residential areas.In this example, the bund is intended to store stormwater in the valley. The engineers... https://www.jove.com/v/18117 77 2025-03-26T22:22:22+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40752/40752_article_thumb_40752.jpg Microbial Wastewater Treatment Microbial communities in aquatic ecosystems play a key role in the natural breakdown of contaminants introduced through domestic and industrial effluents. Acting as biological catalysts, these microbes change and mineralize a wide range of organic and inorganic pollutants under different redox conditions.In oxygen-rich surface waters, aerobic heterotrophs lead organic matter breakdown, using oxygen as the terminal electron acceptor to efficiently oxidize substrates to carbon dioxide and water. https://www.jove.com/v/40752 90 2026-05-20T18:06:58+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40787/40787_article_thumb_40787.jpg Biological Treatment of Effluent and Waste Water Biological wastewater treatment relies on the metabolic activity of microorganisms to remove pollutants from sewage. In modern treatment systems, this process is organized into sequential stages that progressively reduce solid material, dissolved organic matter, and microbial contamination. Each stage plays a distinct role in improving water quality and preparing the effluent for safe discharge or reuse.Primary and Secondary TreatmentPrimary treatment is a physical process that removes large... https://www.jove.com/v/40787 90 2026-05-20T18:26:03+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54095.jpg Watershed Planning within a Quantitative Scenario Analysis Framework There is a critical need for tools and methodologies capable of managing aquatic systems in the face of uncertain future conditions. We provide methods for conducting a targeted watershed assessment that enables resource managers to produce landscape-based cumulative effects models for use within a scenario analysis management framework. https://www.jove.com/v/54095 764 2016-07-24T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55391.jpg Vegetated Treatment Systems for Removing Contaminants Associated with Surface Water Toxicity in Agriculture and Urban Runoff This article summarizes the design attributes and the effectiveness of treatment systems that treat urban stormwater and agriculture irrigation runoff to remove pesticides and other contaminants associated with aquatic toxicity. https://www.jove.com/v/55391 529 2017-05-15T19:30:00+00:00 JoVE no https://visualize.jove.com/16530334-out-of-time-a-possible-link-between-mirror-neurons-autism-and-electromagnetic-radiation monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11294.jpg The Wave Nature of Light The nature of light has been a subject of inquiry since antiquity. In the seventeenth century, Isaac Newton performed experiments with lenses and prisms and was able to demonstrate that white light consists of the individual colors of the rainbow combined together. Newton explained his optics findings in terms of a "corpuscular" view of light, in which light was composed of streams of extremely tiny particles traveling at high speeds according to Newton's laws of motion. Others in the... https://www.jove.com/v/11294 132 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12443.jpg Mutations Mutations are changes in the sequence of DNA. These changes can occur spontaneously or they can be induced by exposure to environmental factors. Mutations can be characterized in a number of different ways: whether and how they alter the amino acid sequence of the protein, whether they occur over a small or large area of DNA, and whether they occur in somatic cells or germline cells. Chromosomal Alterations Are Large-Scale Mutations While point mutations are changes in a single nucleotide in... https://www.jove.com/v/12443 95 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13022.jpg Dual Nature of Electromagnetic (EM) Radiation Electromagnetic (EM) radiation consists of electric and magnetic field components oscillating in planes perpendicular to each other and mutually perpendicular to radiation propagation through space. EM radiation can be classified as a wave, characterized by the properties of waves such as wavelength (denoted as λ) and frequency (represented by ν). Wavelength is the distance between two consecutive peaks (the highest point) or troughs (the lowest point) in the wave. Frequency is the number of... https://www.jove.com/v/13022 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/19610.jpg Autism Spectrum Disorder Autism spectrum disorder (ASD) is a neurodevelopmental condition marked by persistent deficits in social communication and interaction alongside restrictive and repetitive behaviors or interests. ASD is sometimes accompanied by intellectual impairment. These core symptoms manifest differently among individuals, ranging from mild to severe. The disorder's complexity extends beyond its clinical presentation, encompassing a diverse range of biological, cognitive, and sociocultural influences.<br... https://www.jove.com/v/19610 79 JoVE no https://cloudfront.jove.com/files/ftp_upload/40801/40801_article_thumb_40801.jpg Gut-Brain Axis The gut–brain axis is a bidirectional communication system that connects the gastrointestinal tract and the brain. This interaction is mediated through multiple pathways, including the vagus nerve, hormonal signals, immune responses, and chemical messengers produced by gut microbes.Microbial Contributions to Brain FunctionGut microbiota contributes significantly to brain function by producing neuroactive compounds. These include neuroactive compounds that influence neurotransmitters such as... https://www.jove.com/v/40801 82 2026-03-12T20:36:11+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51412.jpg EEG Mu Rhythm in Typical and Atypical Development Assessment of the EEG mu rhythm provides a unique methodology for examining brain activity and when combined with behaviorally based assays, can be a powerful tool for elucidating aspects of social cognition, such as imitation, in clinical populations. https://www.jove.com/v/51412 710 2014-04-10T05:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66846.jpg Strategies for Assessing Autistic-Like Behaviors in Mice Rodent models are valuable tools for studying core behaviors related to autism spectrum disorder (ASD). In this article, we expound on two behavioral tests for modeling the core features of ASD in mice: self-grooming, which assesses repetitive behavior, and the three-chamber social interaction test, which documents social impairments. https://www.jove.com/v/66846 458 2024-09-20T20:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/69155.jpg Dynamic Clamp Methods to Investigate Impaired Neuronal Excitability Associated with Autism Dynamic clamp electrophysiology can establish causal links between neuronal firing deficits and ion channel dysfunction. We describe dynamic clamp methods and protocols in mouse cerebellar Purkinje neurons, noting useful resources and technical considerations. In a representative study, we add modeled sodium conductance to Tsc1-/- Purkinje neurons to rescue repetitive firing. https://www.jove.com/v/69155 524 2025-10-17T21:20:00+00:00 JoVE no https://visualize.jove.com/16535743-combined-light-microscopy-and-attenuated-total-reflection-fourier-transform-infrared-spectroscopy-for-integration-of-biofilm-structure-distribution-and-chemistry-at-solid-liquid-interfaces monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13396.jpg Total Internal Reflection Fluorescence Microscopy Total internal reflection fluorescence microscopy or TIRF is an advanced microscopic technique used to visualize fluorophores in samples close to a solid surface with a higher refractive index, such as a glass coverslip. TIRF only allows fluorophores in proximity to the solid surface to be excited. When light from a medium with a lower refractive index (such as air) hits the glass coverslip at a critical angle, the light undergoes total internal reflection stead of passing through the glass. https://www.jove.com/v/13396 65 JoVE no https://cloudfront.jove.com/files/ftp_upload/19459/19459_article_thumb_19459.jpg Three-Dimensional Microscopy in Microbiology Three-dimensional imaging techniques are essential in cell biology, allowing researchers to visualize intricate cellular structures with high resolution. Two prominent methods, Differential Interference Contrast Microscopy (DIC) and Confocal Scanning Laser Microscopy (CSLM), provide distinct advantages for imaging live and thick specimens, respectively.Differential Interference Contrast MicroscopyDIC microscopy enhances contrast in transparent, unstained samples by converting phase... https://www.jove.com/v/19459 88 2025-06-12T16:25:32+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50639.jpg Concurrent Quantification of Cellular and Extracellular Components of Biofilms A protocol for the concurrent quantification and comparison of three cellular and extracellular components within biofilms is presented. The methodology involves the use of confocal laser scanning microscopy, biofilm structural analysis and visualization software, and statistical analysis software. https://www.jove.com/v/50639 618 2013-12-11T04:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53158.jpg Single Molecule Fluorescence Microscopy on Planar Supported Bilayers Preparation of protein-functionalized planar glass-supported lipid bilayers, determination of protein mobility within and measurement of protein densities is shown here. A roadmap to building a noise-reduced Total Internal Reflection microscope is outlined, which allows visualizing single bilayer-resident fluorochromes with high spatiotemporal resolution. https://www.jove.com/v/53158 1200 2015-10-31T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55884.jpg Soft Lithographic Procedure for Producing Plastic Microfluidic Devices with View-ports Transparent to Visible and Infrared Light A protocol for the fabrication of plastic microfluidic devices with transparent view-ports for visible and infrared light imaging is described. https://www.jove.com/v/55884 626 2017-08-17T20:00:00+00:00 JoVE no https://visualize.jove.com/16541107-rna-binding-imps-promote-cell-adhesion-and-invadopodia-formation monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4119.jpg Quantitative Measurement of Invadopodia-mediated Extracellular Matrix Proteolysis in Single and Multicellular Contexts We describe the prototypical method for producing microscope coverslips coated with fluorescent gelatin for visualizing invadopodia-mediated matrix degradation. Computational techniques using available software are presented for quantifying the resultant levels of matrix proteolysis by single cells within a mixed population and for multicellular groups encompassing entire microscopic fields. https://www.jove.com/v/4119 863 2012-08-27T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11950.jpg Phosphoinositides and PIPs Phosphoinositides are a group of phospholipids containing a glycerol backbone with two fatty acid chains and a phosphate attached to a myoinositol sugar ring. The inositol head group extends into the cytoplasm, where it is modified by adding phosphate groups to form phosphatidylinositol phosphates or PIPs. Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane... https://www.jove.com/v/11950 102 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12253.jpg Mechanism of Filopodia Formation Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles. Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication... https://www.jove.com/v/12253 99 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12254.jpg Cancer Cell Migration through Invadopodia Invadosome is a broad category of cell surface structures with proteolytic activity that degrades the extracellular matrix (ECM). Invadosomes are present in normal cell types, including macrophages, endothelial cells, and neurons, as well as tumor cells. Although the macrophage podosomes and tumor cell invadopodia are classified as invadosomes, they have different structures, molecular pathways, and functions. Podosomes are short structures that last for a few minutes. However, invadopodia can... https://www.jove.com/v/12254 95 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12255.jpg Mechanism of Lamellipodia Formation Cells migrating in response to external stimuli form lamellipodia, which are thin membrane protrusions supported by a mesh of linked, branched, or unbranched actin filaments. These actin filaments interact with myosin motor proteins, creating the dynamic actomyosin complex within the cytoskeleton. Contractility, or the ability to generate contractile stress, is inherent to the actomyosin complex. It helps cells detect the stiffness of the surrounding ECM and exert contractile force for... https://www.jove.com/v/12255 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13350.jpg Intracellular Signaling Affects Focal Adhesions Integrins act both as extracellular input receivers and as intracellular processing activators. As their name suggests, integrins are entirely integrated into the membrane structure. Their hydrophobic membrane-spanning regions interact with the phospholipid bilayer's hydrophobic region. These membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors. They activate intracellular response cascades when their effectors are bound and active. Some... https://www.jove.com/v/13350 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13363.jpg Immunoglobulin-like Cell Adhesion Molecules Immunoglobulin-like cell adhesion molecules or Ig-CAMs are a versatile group of cell surface glycoproteins belonging to the immunoglobulin protein superfamily. Ig-CAMs possess the characteristic immunoglobulin protein domains and other domains such as the fibronectin type III domain. The Ig domains are glycosylated to varying degrees in different Ig-CAMs. Ig-CAMs exhibit either homophilic binding (to other Ig-CAMs) or heterophilic binding (to other ligands such as integrins). While most Ig-CAMs... https://www.jove.com/v/13363 91 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51762.jpg Bead Aggregation Assays for the Characterization of Putative Cell Adhesion Molecules Here we present a simple, rapid method for characterizing the intrinsic adhesive properties of putative cell adhesion molecules. The secreted, epitope-tagged ectodomain of a cell adhesion molecule is captured from the culture medium on small, uniform functionalized beads. These beads can then be used immediately in simple bead aggregation assays. https://www.jove.com/v/51762 495 2014-10-17T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55060.jpg Ligand Nano-cluster Arrays in a Supported Lipid Bilayer We present a protocol to functionalize glass with nanometric protein patches surrounded by a fluid lipid bilayer. These substrates are compatible with advanced optical microscopy and are expected to serve as platform for cell adhesion and migration studies. https://www.jove.com/v/55060 634 2017-04-23T21:00:00+00:00 JoVE no https://visualize.jove.com/16563537-the-theory-of-the-whole-brain-work monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4125.jpg Co-analysis of Brain Structure and Function using fMRI and Diffusion-weighted Imaging We describe a novel approach for simultaneous analysis of brain function and structure using magnetic resonance imaging (MRI). We assess brain structure with high-resolution diffusion-weighted imaging and white-matter fiber tractography. Unlike standard structural MRI, these techniques allow us to directly relate anatomical connectivity to functional properties of brain networks. https://www.jove.com/v/4125 1026 2012-11-08T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14903.jpg Anatomy of the Brain: Major Regions The brain is the most complex organ in the human body. It consists of four main parts: the cerebrum, diencephalon, cerebellum, and brainstem. The cerebrum is the largest section of the brain and divides into left and right hemispheres, separated by a deep fissure. The cerebral outer layer of grey matter — the cerebral cortex — comprises elevations called gyri and shallow groves called sulci. The inner portion of white matter includes long nerve fibers known as axons, which connect various areas... https://www.jove.com/v/14903 80 2025-06-13T16:08:32+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14916.jpg Functional Brain Systems: Reticular Formation The reticular formation is a complex network of gray and white matter located within the brainstem extending from the medulla to the midbrain. Within the reticular formation, there are several distinct nuclei that can be classified into three broad categories. The Raphe nuclei are located along the midline of the brainstem. They are primarily known for their role in synthesizing and releasing serotonin, a neurotransmitter involved in regulating mood, appetite, sleep, and circadian rhythms. The... https://www.jove.com/v/14916 73 2025-06-13T16:16:18+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14945.jpg Higher Mental Functions of the Brain: Language Language is a system of communication that allows the expression of thoughts, ideas, and feelings. The brain processes language in both hemispheres. Language formation and comprehension take place in the dominant hemisphere. The dominant hemisphere is responsible for understanding the meaning of spoken, written, or sign language, as well as the ability to communicate. For most people, the left hemisphere is the dominant one. The right hemisphere, then, gives tone and emotional context to the... https://www.jove.com/v/14945 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17746.jpg Organization of the Brain The brain is an integral component of the nervous system and serves as the center for processing sensory inputs, making decisions, and directing bodily actions. This complex organ is organized into three primary sections: the hindbrain, midbrain, and forebrain, each responsible for a range of vital functions. Hindbrain The hindbrain, located at the base of the brain, plays a vital role in regulating automatic processes that sustain life. It includes the medulla oblongata, which is essential for... https://www.jove.com/v/17746 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17747.jpg Cerebral Hemispheres The human brain, a complex organ, is functionally divided into two cerebral hemispheres—left and right. These hemispheres are interconnected by a structure of paramount importance, the corpus callosum. This substantial bundle of neural fibers is not just a bridge between the hemispheres but a crucial element for the brain's comprehensive functioning. It enables efficient communication between the two hemispheres, allowing each side of the brain to control and receive sensory and motor... https://www.jove.com/v/17747 65 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17748.jpg Lobes of the Cerebrum The cerebral cortex, a critical structure of the brain, is intricately divided into two hemispheres, each consisting of four distinct lobes: occipital, temporal, frontal, and parietal. These lobes function cooperatively to regulate various cognitive and sensory functions, forming the basis of our complex neural capabilities. Frontal lobe The frontal lobes, located behind the forehead, are the command center of our brain, controlling personality, intelligence, and voluntary muscle movements. https://www.jove.com/v/17748 82 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61941.jpg Microdissection of Mouse Brain into Functionally and Anatomically Different Regions We present a hands-on, step-by-step, rapid protocol for mouse brain removal and dissection of discrete regions from fresh brain tissue. Obtaining brain regions for molecular analysis has become routine in many neuroscience labs. These brain regions are immediately frozen to obtain high quality transcriptomic data for system level analysis. https://www.jove.com/v/61941 486 2021-02-15T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67694.jpg Serial Two-Photon Tomography of the Whole Marmoset Brain for Neuroanatomical Analyses Serial two-photon tomography (STPT) imaging is a technique to image a mass of tissue in its three-dimensional shape by combining two-photon imaging with automatic stage control and microtome slicing. Here we describe a protocol for implementing it for marmoset brains to better understand their structural features. https://www.jove.com/v/67694 242 2025-01-17T22:20:00+00:00 JoVE no https://visualize.jove.com/16627432-first-multi-centre-evaluation-of-a-knowledge-based-implant-assistant-for-implantable-cardioverter-defibrillators monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3750.jpg A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation Dual-chamber implantable cardioverter-defibrillators (ICDs) may improve detection of atrial fibrillation as well as differentiation of tachycardias. However, this advantage is undermined by complications associated with the second electrode, which is required in conventional dual chamber devices. Therefore, BIOTRONIK has developed a new electrode called the LinoxSMART S DX that, when used in conjunction with the Lumax DX ICD, offers dual-chamber detection without the risks associated with the... https://www.jove.com/v/3750 1000 2012-02-28T22:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13286.jpg Pulse rhythm Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding. Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle... https://www.jove.com/v/13286 90 JoVE no https://cloudfront.jove.com/files/ftp_upload/17888/17888_article_thumb_17888.jpg Cardiac Catheterization I: Pre-Procedure Overview Cardiac catheterization is an invasive diagnostic technique used to identify and evaluate structural and functional diseases of the heart and major blood vessels. This technique diagnoses congenital heart disease, coronary artery disease, valvular heart disease, and coronary spasms and assesses ventricular function. It helps guide treatment decisions, including the need for revascularization procedures like percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) and... https://www.jove.com/v/17888 88 2025-06-19T16:14:01+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17889/17889_article_thumb_17889.jpg Cardiac Catheterization II: Right Heart Catheterization Right Heart Catheterization: An OverviewRight heart catheterization is an invasive diagnostic procedure that measures right-sided cardiac and pulmonary artery pressures, calculates cardiac output, and identifies intracardiac shunts. It provides detailed hemodynamic data essential for diagnosing and managing various cardiovascular conditions, such as pulmonary hypertension.Access SitesCommon access sites for right heart catheterization include the internal jugular vein in the neck region, the... https://www.jove.com/v/17889 81 2025-06-19T16:14:22+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17890/17890_article_thumb_17890.jpg Cardiac Catheterization III: Left Heart Catheterization Left heart catheterization is an invasive diagnostic procedure used to evaluate the function and structure of the left side of the heart. It is generally performed to diagnose and treat cardiovascular conditions such as valve abnormalities, coronary artery disease, and congenital heart defects.Diagnostic and therapeutic purposesLeft heart catheterization serves various diagnostic and therapeutic purposes, including:Assessing coronary artery bypass grafts.Evaluating coronary artery disease in... https://www.jove.com/v/17890 84 2026-01-28T21:01:00+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17948/17948_article_thumb_17948.jpg Cardiopulmonary Resuscitation III: AED Use Introduction to AEDAn Automated External Defibrillator (AED) is a portable medical device that analyzes the heart's rhythm and, if necessary, delivers an electrical shock to help the heart re-establish an effective rhythm during sudden cardiac arrest (SCA). SCA occurs when the heart suddenly and unexpectedly stops beating, leading to a loss of blood flow to the brain and other vital organs. In such emergencies, time is of the essence, and using an AED, combined with Cardiopulmonary... https://www.jove.com/v/17948 83 2025-06-19T16:38:36+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17962/17962_article_thumb_17962.jpg Cardiomyopathy V: Interprofessional Care Managing cardiomyopathy involves addressing underlying or precipitating causes, treating heart failure with medications, and implementing dietary changes and a balanced exercise and rest regimen.Lifestyle ModificationsCardiomyopathy patients should adopt a low-sodium diet to reduce fluid retention and manage heart failure. A personalized exercise and rest plan helps maintain physical fitness without overstraining the heart. Avoiding alcohol and tobacco is essential to prevent further damage to... https://www.jove.com/v/17962 89 2025-06-19T16:42:59+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62140.jpg Use of a Percutaneous Ventricular Assist Device/Left Atrium to Femoral Artery Bypass System for Cardiogenic Shock The following article describes the stepwise procedure for placement of a device (e.g., Tandemheart) in cardiogenic shock (CS) that is a percutaneous left ventricular assist device (pLVAD) and a left atrial to femoral artery bypass (LAFAB) system that bypasses and supports the left ventricle (LV) in CS. https://www.jove.com/v/62140 459 2021-08-16T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67958.jpg Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System This study introduces a novel approach for real-time cardiac mapping using a noninvasive, imageless electrocardiographic imaging system. This system enables the acquisition of electrophysiological cardiac maps without requiring pre-procedural computed tomography or magnetic resonance imaging scans, enabling efficient guidance for cardiac procedures such as ablation and cardiac resynchronization therapy implants. https://www.jove.com/v/67958 617 2025-04-11T21:20:00+00:00 JoVE no https://visualize.jove.com/16637629-pattern-based-discrimination-of-enantiomeric-and-structurally-similar-amino-acids-an-optical-mimic-of-the-mammalian-taste-response monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10851.jpg Gustation Gustation is a chemical sense that, along with olfaction (smell), contributes to our perception of taste. It starts with the activation of receptors by chemical compounds (tastants) dissolved in the saliva. The saliva and filiform papillae on the tongue distribute the tastants and increase their exposure to the taste receptors. Taste receptors are found on the surface of the tongue as well as on the soft palate, the pharynx, and the upper esophagus. On the tongue, taste receptors are contained... https://www.jove.com/v/10851 103 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11251.jpg Molecular Models Physical models representing molecular architectures of chemical compounds play essential roles in understanding chemistry. The use of molecular models makes it easier to visualize the structures and shapes of atoms and molecules. Skeletal Model Simpler two-dimensional representations of chemical compounds are accomplished using skeletal models. The illustration shows only the molecular framework or bonds without explicitly showing the atoms. In this representation, many of the carbon atoms... https://www.jove.com/v/11251 120 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13000.jpg ¹H NMR Chemical Shift Equivalence: Homotopic and Heterotopic Protons Protons in identical electronic environments within a molecule are chemically equivalent and have the same chemical shift. The replacement test is a useful tool to identify chemical equivalence and predict NMR spectra. A substituent replaces each of the protons being examined and the resulting molecules are compared. If the same molecule is obtained, the protons are equivalent or homotopic. Replacement of any hydrogens in ethane by chlorine yields chloroethane because all six protons are... https://www.jove.com/v/13000 63 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13323.jpg G-Protein Gated Ion Channels GPCRs are primarily responsible for our sense of smell, taste, and vision. The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response. Sensory organs,... https://www.jove.com/v/13323 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14967.jpg Taste Buds and Receptors Gustation, or the sense of taste, is intrinsically linked to the anatomical structures located on the tongue. This organ's surface, along with the entirety of the oral cavity, is adorned with stratified squamous epithelium. Evident on the tongue are elevated structures known as papillae (singular = papilla), which house the mechanisms for the transduction of gustatory stimuli. Four distinct types of papillae exist, each identified by their unique morphological attributes: the circumvallate,... https://www.jove.com/v/14967 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14968.jpg The Physiology of Taste The perception of a salty flavor is facilitated by sodium ions within the oral salivary fluid. Upon consumption of a salty substance, salt crystals disassemble, leading to the liberation of its constituents—Na+ and Cl- ions. These ions subsequently dissolve into the salivary fluid present in the oral cavity. The external environment of the gustatory cells experiences an elevation in Na+ concentration, thereby establishing a potent concentration gradient. This gradient propels the diffusion of... https://www.jove.com/v/14968 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54403.jpg Taste Preference Assay for Adult Drosophila Taste is an important sensory process which facilitates attraction to beneficial substances and avoidance of toxic substances. This protocol describes a simple ingestion assay for determining Drosophila gustatory preference for a given chemical compound. https://www.jove.com/v/54403 271 2016-09-08T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55868.jpg New Methods to Study Gustatory Coding We present three new methods to study gustatory coding. Using a simple animal, the moth Manduca sexta (Manduca), we describe a dissection protocol, the use of extracellular tetrodes to record the activity of multiple gustatory receptor neurons, and a system for delivering and monitoring precisely timed pulses of tastants. https://www.jove.com/v/55868 659 2017-06-29T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62051.jpg A Rapid Food-Preference Assay in Drosophila We present a protocol for a two-choice feeding assay for flies. This feeding assay is fast and easy to run and is suitable not only for small-scale laboratory research, but also for high-throughput behavioral screens in flies. https://www.jove.com/v/62051 433 2021-02-11T12:30:00+00:00 JoVE no https://visualize.jove.com/16649564-adaptive-predictive-functional-control-of-a-class-of-nonlinear-systems monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16031.jpg Control Systems Control systems are everywhere in contemporary society, influencing diverse applications from aerospace to automated manufacturing. These systems can be found naturally within biological processes, such as blood sugar regulation and heart rate adjustment in response to stress, as well as in man-made systems like elevators and automated vehicles. A control system is essentially a network of subsystems and processes that collaboratively convert specific inputs into desired outputs. At the heart... https://www.jove.com/v/16031 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16045.jpg Classification of Systems-I Linearity is a system property characterized by a direct input-output relationship, combining homogeneity and additivity. Homogeneity dictates that if an input x(t) is multiplied by a constant c, the output y(t) is multiplied by the same constant. Mathematically, this is expressed as: Additivity means that the response to the sum of multiple inputs is the sum of their individual responses. For inputs x1(t) and x2(t) producing outputs y1(t) and y2(t), respectively: Combining homogeneity and... https://www.jove.com/v/16045 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16094.jpg Feedback control systems Feedback control systems are categorized in various ways based on their design, analysis, and signal types. Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity... https://www.jove.com/v/16094 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16099.jpg Linear Approximation in Frequency Domain Linear systems are characterized by two main properties: superposition and homogeneity. Superposition allows the response to multiple inputs to be the sum of the responses to each individual input. Homogeneity ensures that scaling an input by a scalar results in the response being scaled by the same scalar. In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear. https://www.jove.com/v/16099 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16103.jpg Linear Approximation in Time Domain Nonlinear systems often require sophisticated approaches for accurate modeling and analysis, with state-space representation being particularly effective. This method is especially useful for systems where variables and parameters vary with time or operating conditions, such as in a simple pendulum or a translational mechanical system with nonlinear springs. For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length, the... https://www.jove.com/v/16103 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16125.jpg Controller Configurations Controller configurations are crucial in a car's cruise control system because they manage speed over time to maintain a consistent pace regardless of road conditions, thereby meeting design goals. In traditional control systems, fixed-configuration design involves predetermined controller placement. System performance modifications are known as compensation. Control-system compensation involves various configurations, most commonly series or cascade compensation, in which the controller aligns... https://www.jove.com/v/16125 82 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61092.jpg WheelCon: A Wheel Control-Based Gaming Platform for Studying Human Sensorimotor Control WheelCon is a novel, free and open-source platform to design video games that noninvasively simulates mountain biking down a steep, twisting, bumpy trail. It contains components presenting in human sensorimotor control (delay, quantization, noise, disturbance, and multiple feedback loops) and allows researchers to study the layered architecture in sensorimotor control. https://www.jove.com/v/61092 498 2020-08-15T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61943.jpg Real-Time Proxy-Control of Re-Parameterized Peripheral Signals using a Close-Loop Interface We present protocols and methods of analyses to build co-adaptive interfaces that stream, parameterize, analyze, and modify human body and heart signals in close-loop. This setup interfaces signals derived from the peripheral and central nervous systems of the person with external sensory inputs to help track biophysical change. https://www.jove.com/v/61943 714 2021-05-08T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63575.jpg Design and Application of a Fault Detection Method Based on Adaptive Filters and Rotational Speed Estimation for an Electro-Hydrostatic Actuator In this paper, an adaptive filter based on a normalized least mean square (NLMS) algorithm and a rotational speed estimation method are introduced to detect the electrical and hydraulic faults of the electro-hydrostatic actuator (EHA). The efficacy and feasibility of the aforementioned methods are verified through simulations and experiments. https://www.jove.com/v/63575 405 2022-10-28T20:00:00+00:00 JoVE no https://visualize.jove.com/16697382-angiotensin-ii-disrupts-inhibitory-avoidance-memory-retrieval monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3893.jpg Extinction Training During the Reconsolidation Window Prevents Recovery of Fear Conditioned fear can be diminished through an inhibitory process called extinction, but can resurface under conditions such as the passage of time or exposure to stress. Our protocol presents a novel way of preventing fear recovery by introducing extinction during the reconsolidation window (the re-storage phase of a reactivated memory). https://www.jove.com/v/3893 677 2012-08-24T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14479.jpg Drugs Affecting Neurotransmitter Release or Uptake Certain drugs can affect how neurotransmitters called catecholamines, are released or taken back up in the adrenergic neuron. They can have different effects on the body's sympathetic transmission. Reserpine, a natural compound found in the Rauwolfia shrub, blocks a transporter called vesicular monoamine transporter (VMAT), which leads to a buildup of catecholamines in the cell and reduces sympathetic transmission. Another drug called guanethidine works in multiple ways, including blocking... https://www.jove.com/v/14479 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15023.jpg Antihypertensive Drugs: Angiotensin-Converting Enzyme Inhibitors Angiotensin-converting enzyme (ACE), a vital component of the renin-angiotensin-aldosterone system, is abundant in lung endothelial cells. ACE converts the inactive decapeptide, angiotensin I, into the active octapeptide, angiotensin II. This potent vasoconstrictor narrows blood vessels, increasing resistance to blood flow and elevating blood pressure. Angiotensin II also stimulates aldosterone production, encouraging kidney cells to reabsorb more sodium and water from urine, thereby increasing... https://www.jove.com/v/15023 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15024.jpg Antihypertensive Drugs: Angiotensin II Receptor Blockers In the renin-angiotensin-aldosterone system, a hormone called angiotensin II plays a crucial role. It binds to the AT1 receptors in vascular smooth muscles coupled with Gq proteins. The activation of these receptors activates an enzyme called phospholipase C, which releases two molecules: inositol trisphosphate and diacylglycerol. These molecules cause a chain reaction that leads to the phosphorylation of myosin light chains and promotes interaction between actin and myosin, leading to smooth... https://www.jove.com/v/15024 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15025.jpg Antihypertensive Drugs: Direct Renin Inhibitors The renin-angiotensin-aldosterone system (RAAS) is an intricate physiological pathway involving numerous enzymes and hormones, including renin, angiotensin-converting enzyme (ACE), angiotensin I and II, and aldosterone. Imbalances within this system increase the production of angiotensin II and aldosterone. Increased angiotensin II levels promote vasoconstriction and blood pressure elevation. Concurrently, higher aldosterone levels stimulate sodium and water reabsorption in the kidneys,... https://www.jove.com/v/15025 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15037.jpg Heart Failure Drugs: Inhibitors of Renin-Angiotensin System The activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) contributes to cardiac remodeling, and inhibiting the RAAS is a pharmacological target in heart failure management. As a result, neurohumoral modulation is a crucial treatment principle for managing heart failure. This approach involves using medications like ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), β-blockers, mineralocorticoid receptor antagonists (MRAs), and neutral... https://www.jove.com/v/15037 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18185.jpg Role of Amygdala in Memory The amygdala is a small, almond-shaped structure responsible for processing and storing memories, particularly those linked to emotions like fear and stress. It plays an essential role in the brain's response to emotionally significant events and often enhances memory formation by triggering stress hormone release. The amygdala is vital for encoding and retrieving memories associated with fear or stress, a process that is adaptive by helping organisms avoid dangerous situations. One of the... https://www.jove.com/v/18185 76 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52151.jpg Disrupting Reconsolidation of Fear Memory in Humans by a Noradrenergic β-Blocker Disrupting reconsolidation is a promising approach to dampen the behavioral expression of fear memory in patients with anxiety disorders or posttraumatic stress disorder. In a series of human fear conditioning studies we showed that disrupting reconsolidation by the noradrenergic β-blocker propranolol is very effective in erasing conditioned fear responding. https://www.jove.com/v/52151 512 2014-12-18T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53866.jpg Receptor Autoradiography Protocol for the Localized Visualization of Angiotensin II Receptors Here we present a protocol to describe the localization of angiotensin II Type 1 receptors in the rat brain by quantitative, densitometric, in vitro receptor autoradiography using an iodine-125 labeled analog of angiotensin II. https://www.jove.com/v/53866 723 2016-06-07T21:30:00+00:00 JoVE no https://visualize.jove.com/16700081-how-is-leflunomide-prescribed-and-used-in-australia-analysis-of-prescribing-and-adverse-effect-reporting monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2259.jpg The Use of Carboxyfluorescein Diacetate Succinimidyl Ester (CFSE) to Monitor Lymphocyte Proliferation CFSE covalently labels long-lived intracellular molecules with the fluorescent dye, carboxyfluorescein. As such, when a CFSE-labeled cell divides, its progeny have half the amount of fluorescence, which can thereby be used to assess cell division. This article describes the procedures typically used for labeling mouse lymphocytes with CFSE. https://www.jove.com/v/2259 250 2010-10-13T00:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14376.jpg Drug Regulation Drug regulation encompasses the management of drug usage by evaluating its safety and efficacy through assessments conducted by regulatory authorities. Regrettably, the history of drug regulation is marred by several catastrophic events. One such incident is the Elixir Sulfanilamide tragedy, in which the toxic compound diethyl glycol was included in a sweet-tasting medication, leading to numerous fatalities. This event prompted the enactment of the Food, Drug, and Cosmetic Act in 1938. Under... https://www.jove.com/v/14376 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14384.jpg Pharmacovigilance Post-marketing surveillance is a critical component of pharmaceutical regulation, often uncovering unanticipated adverse drug reactions (ADRs) once a drug is widely used over an extended period. This process, termed pharmacovigilance, aims to detect, evaluate, and minimize harmful effects related to medication use. The data collection for pharmacovigilance depends on spontaneous reporting systems, where healthcare professionals or patients voluntarily report suspected ADRs. In some cases, there... https://www.jove.com/v/14384 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15231.jpg Antiasthma Drugs: Leukotriene Modifiers Leukotriene modifiers, or cysteinyl leukotriene receptor antagonists, are medications used to manage chronic asthma. These agents target specific inflammatory mediators produced during arachidonic acid metabolism, an essential process in generating inflammation in the body. Leukotriene modifiers work through two distinct mechanisms: 5-Lipoxygenase Inhibitors: Some drugs in this class, like zileuton (Zyflo), inhibit an enzyme called 5-lipoxygenase. This enzyme is crucial in synthesizing... https://www.jove.com/v/15231 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15391.jpg Drugs for Treatment of Crohn's Disease in IBD Using Immunomodulatory Agents Crohn's disease is an inflammatory bowel disorder marked by chronic inflammation of the GI tract. Various treatment strategies for Crohn's disease are employed, such as immunomodulatory agents, glucocorticoids, and biologics or anti-TNF therapy. Azathioprine (Imuran), a commonly used immunomodulatory drug for Crohn's disease, is converted in the body to mercaptopurine, which inhibits purine biosynthesis and cell proliferation. Both are utilized in severe cases of Inflammatory Bowel Disease... https://www.jove.com/v/15391 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15393.jpg Drugs for Treatment of Crohn's Disease in IBD Using Glucocorticoids Glucocorticoids, a class of anti-inflammatory drugs, are pivotal in treating moderate to severe Crohn's disease by inducing remission. They exhibit their anti-inflammatory action by inhibiting the production of inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1, and chemokines like IL-8. In addition, they reduce the expression of inflammatory cell adhesion molecules and inhibit gene transcription of nitric oxide synthase, phospholipase A2, cyclooxygenase-2 (COX-2),... https://www.jove.com/v/15393 81 JoVE no https://cloudfront.jove.com/files/ftp_upload/17189/17189_article_thumb_17189.jpg Therapeutic Drug Monitoring: Affecting Factors Therapeutic Drug Monitoring (TDM) is the clinical practice of measuring specific drug levels in a patient's blood or body tissues to manage and optimize therapy. TDM is crucial for drugs with narrow therapeutic windows, like warfarin and phenytoin, where incorrect doses can lead to treatment failure or severe side effects. This monitoring ensures the dosage administered is within a safe and effective range. The factors affecting therapeutic drug monitoring include:Patient-Specific Factors:a. https://www.jove.com/v/17189 89 2025-10-03T14:00:19+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51627.jpg The Use of Fluorescent Target Arrays for Assessment of T Cell Responses In vivo The ability to monitor T cell responses in detail in vivo is important for the development of our understanding of the immune response. Here we describe the use of fluorescent target arrays (FTAs) in an in vivo T cell assay that assesses >250 parameters simultaneously by flow cytometry. https://www.jove.com/v/51627 729 2014-06-19T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56084.jpg Optimized LC-MS/MS Method for the High-throughput Analysis of Clinical Samples of Ivacaftor, Its Major Metabolites, and Lumacaftor in Biological Fluids of Cystic Fibrosis Patients Ivacaftor and ivacaftor-lumacaftor combination are two new CF drugs. However, there is still a dearth of understanding on their PK/PD and pharmacology. We present an optimized HPLC-MS technique for the simultaneous analysis of ivacaftor and its major metabolites, and lumacaftor. https://www.jove.com/v/56084 374 2017-10-15T20:00:00+00:00 JoVE no https://visualize.jove.com/16725231-type-i-interferons-are-essential-for-the-efficacy-of-replicase-based-dna-vaccines monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15355.jpg Immune Response Against Viral Pathogens The immune system's response to viral infections is a complex and coordinated process involving natural killer (NK) cells, T cell-mediated responses, and antibody-mediated responses. NK Cells NK cells are a crucial part of our innate immune system, acting as the first line of defense against viral infections. These cells can recognize and kill infected cells without prior exposure to the virus, effectively slowing down the spread of infection. Additionally, NK cells produce proinflammatory... https://www.jove.com/v/15355 89 JoVE no https://cloudfront.jove.com/files/ftp_upload/19590/19590_article_thumb_19590.jpg DNA Bacteriophages Bacteriophages, or phages, are viruses that specifically infect bacteria, utilizing their genetic material to hijack host cellular machinery for replication. DNA bacteriophages employ single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA) genomes. These phages exhibit diverse replication strategies and host interactions, influencing their ecological roles and applications in biotechnology and medicine.ssDNA BacteriophagesssDNA phages, with their small genomes, utilize unique strategies to... https://www.jove.com/v/19590 86 2025-06-12T16:30:01+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19592/19592_article_thumb_19592.jpg Viruses with RNA Genomes RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. This classification dictates how they exploit host cellular machinery for protein synthesis and replication. Some RNA viruses also utilize reverse transcription as part of their life cycle, further diversifying their replication strategies.Positive-Strand RNA VirusesPositive-strand RNA viruses have genomes that function directly as messenger... https://www.jove.com/v/19592 89 2025-06-12T16:30:23+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40818/40818_article_thumb_40818.jpg Vaccines Vaccines are among the most effective tools in preventive medicine, designed to prepare the immune system to recognize and combat infectious agents. By introducing antigens—substances that the immune system identifies as foreign—vaccines stimulate an adaptive immune response that leads to immunological memory. This immunological memory enables the body to mount a faster and more effective response upon future exposures to the actual pathogen.Vaccines can be categorized based on the type of... https://www.jove.com/v/40818 81 2026-03-12T20:35:57+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40862/40862_article_thumb_40862.jpg Inhibitors of Viral Protein Synthesis Protein synthesis is indispensable for viral replication, as viruses lack the cellular machinery required for this process and must hijack the host's translational apparatus. In response, host cells deploy a critical innate immune defense involving interferons, specialized cytokines that play a central role in inhibiting viral propagation.Upon viral detection, infected cells release interferons that bind to receptors on adjacent uninfected cells, activating the JAK-STAT signaling pathway and... https://www.jove.com/v/40862 90 2026-03-12T20:36:03+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40863/40863_article_thumb_40863.jpg Inhibitors Of Virion Release Viral replication and dissemination rely on efficient mechanisms for host cell entry, genome replication, assembly, and release. Influenza viruses, such as types A and B, are negative-sense single-stranded RNA viruses with a segmented genome, that depend on two critical surface glycoproteins to carry out these processes: hemagglutinin (HA) and neuraminidase (NA). HA initiates infection by binding to sialic acid residues on the surface of host epithelial cells, facilitating receptor-mediated... https://www.jove.com/v/40863 85 2026-05-20T21:34:12+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51078.jpg Dissecting Innate Immune Signaling in Viral Evasion of Cytokine Production We describe a protocol to measure the antiviral cytokine production in mice infected with a model herpesvirus, murine gamma herpesvirus 68 (γHV68) that is closely-related to human Kaposi’s sarcoma-associated herpesvirus (KSHV) and Epstein-Barr virus (EBV). Utilizing genetically modified mouse strains and mouse embryonic fibroblasts (MEFs), we assessed the antiviral cytokine production both in vivo and ex vivo. “Reconstituting” the expression of innate immune components in knockout embryonic... https://www.jove.com/v/51078 512 2014-03-02T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51593.jpg Stimulation of Cytoplasmic DNA Sensing Pathways In Vitro and In Vivo The aim of the protocol is to use optimal methods for stimulating the cytoplasmic DNA sensing pathways in cells and in vivo. This is achieved by improving the generation of long, double-stranded DNA during blunt-end ligation. Cells or mice are then transfected using a lipid transfection reagent. https://www.jove.com/v/51593 704 2014-09-18T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52650.jpg High-throughput Quantitative Real-time RT-PCR Assay for Determining Expression Profiles of Types I and III Interferon Subtypes This protocol describes a high-throughput qRT-PCR assay for the analysis of type I and III IFN expression signatures. The assay discriminates single base pair differences between the highly similar transcripts of these genes. Through batch assembly and robotic pipetting, the assays are consistent and reproducible. https://www.jove.com/v/52650 600 2015-03-24T23:00:00+00:00 JoVE no https://visualize.jove.com/16793055-multidimensional-shape-similarity-in-the-development-of-visual-object-classification monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3358.jpg Creating Objects and Object Categories for Studying Perception and Perceptual Learning We describe a novel methodology for creating naturalistic 3-D objects and object categories with precisely defined feature variations. We use simulations of the biological processes of morphogenesis and phylogenesis to create novel, naturalistic virtual 3-D objects and object categories that can then be rendered as visual images or haptic objects. https://www.jove.com/v/3358 878 2012-11-02T22:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16045.jpg Classification of Systems-I Linearity is a system property characterized by a direct input-output relationship, combining homogeneity and additivity. Homogeneity dictates that if an input x(t) is multiplied by a constant c, the output y(t) is multiplied by the same constant. Mathematically, this is expressed as: Additivity means that the response to the sum of multiple inputs is the sum of their individual responses. For inputs x1(t) and x2(t) producing outputs y1(t) and y2(t), respectively: Combining homogeneity and... https://www.jove.com/v/16045 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16046.jpg Classification of Systems-II Continuous-time systems have continuous input and output signals, with time measured continuously. These systems are generally defined by differential or algebraic equations. For instance, in an RC circuit, the relationship between input and output voltage is expressed through a differential equation derived from Ohm's law and the capacitor relation, Discrete-time systems have input and output signals at specific intervals, defined at distinct instants by difference equations. An example is a... https://www.jove.com/v/16046 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16861.jpg Aggregates Classification Aggregate classification is generally based on its size, petrographic characteristics, weight, and source. Size classification ranges from coarse to fine aggregates, defined by the size of the particles. Coarse aggregates are particles that do not pass through ASTM sieve No. 4, and aggregates that pass through the sieve are fine aggregates. Petrographic classification groups aggregates based on common mineralogical characteristics. Some of the common mineral groups found in aggregates are... https://www.jove.com/v/16861 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17768.jpg Depth Perception and Spatial Vision Depth perception is the ability to perceive objects three-dimensionally. It relies on two types of cues: binocular and monocular. Binocular cues depend on the combination of images from both eyes and how the eyes work together. Since the eyes are in slightly different positions, each eye captures a slightly different image. This disparity between images, known as binocular disparity, helps the brain interpret depth. When the brain compares these images, it determines the distance to an object. https://www.jove.com/v/17768 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17781.jpg Visual Agnosia Visual agnosia is a condition characterized by the inability to recognize visually presented objects despite having normal vision. For instance, a person with visual agnosia can describe the shape and color of an object but cannot identify or name it. This impairment does not affect their visual field, acuity, color vision, brightness discrimination, language, or memory. An example of this condition in a social setting is someone at a dinner party asking for "that silver thing with a round end"... https://www.jove.com/v/17781 72 JoVE no https://cloudfront.jove.com/files/ftp_upload/19952/19952_article_thumb_19952.jpg Causes of Similarity-Dissimilarity Effect The similarity-dissimilarity effect, a fundamental concept in social psychology, explains how interpersonal similarities and differences influence attraction and social interactions. This effect is supported by three key psychological perspectives: balance theory, social comparison theory, and consensual validation.Balance Theory and Cognitive ConsistencyBalance theory, developed by Fritz Heider, posits that individuals seek cognitive consistency in their relationships. When two people share... https://www.jove.com/v/19952 86 2025-09-18T17:23:53+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63461.jpg A Psychophysics Paradigm for the Collection and Analysis of Similarity Judgments The protocol presents an experimental psychophysics paradigm to obtain large quantities of similarity judgments, and an accompanying analysis workflow. The paradigm probes context effects and enables modeling of similarity data in terms of Euclidean spaces of at least five dimensions. https://www.jove.com/v/63461 492 2022-03-01T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66272.jpg Motion-Acuity Test for Visual Field Acuity Measurement with Motion-Defined Shapes A novel motion-based acuity test that allows the assessment of central and peripheral visual processing in low-vision and healthy individuals, along with goggles limiting peripheral vision compatible with MRI protocols, are described here. This method offers a comprehensive vision assessment for functional impairments and dysfunctions of the visual system. https://www.jove.com/v/66272 385 2024-02-23T21:45:00+00:00 JoVE no https://visualize.jove.com/16795609-a-graphical-judgmental-aid-which-summarizes-obtained-and-chance-reliability-data-and-helps-assess-the-believability-of-experimental-effects monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12801.jpg Review and Preview Data are individual items of information obtained from a population or sample. Data may be classified as qualitative (categorical), quantitative continuous, or quantitative discrete. Because it is not practical to measure the entire population in a study, researchers use samples to represent the population. A random sample is a representative group from the population chosen by using a method that gives each individual in the population an equal chance of being included in the sample. Random... https://www.jove.com/v/12801 73 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13561.jpg Review and Preview In statistics, several tools are used to interpret the data. Measures of central tendency represent the characteristics of the data, such as mean, median, and mode. Additionally, measures of variance like standard deviation and range are used to find the spread of data from the mean. Relative standing measures the distance between data locations. Commonly used measures of relative standings are percentile, z score, and quartiles. Percentiles are a type of fractile that partition data into... https://www.jove.com/v/13561 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13584.jpg What are Estimates? It isn't easy to measure a parameter such as the mean height or the mean weight of a population. So, we draw samples from the population and calculate the mean height or mean weight of the individuals in the sample. This sample data acts as a representative measure of the population parameter. These sample statistics are known as estimates. The estimate for the mean of a sample is denoted by ͞x, whereas the mean of the population is designated as μ. Further, parameters such as the mean,... https://www.jove.com/v/13584 66 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13600.jpg Goodness-of-Fit Test The goodness-of-fit test is a type of hypothesis test which determines whether the data "fits" a particular distribution. For example, one may suspect that some anonymous data may fit a binomial distribution. A chi-square test (meaning the distribution for the hypothesis test is chi-square) can be used to determine if there is a fit. The null and alternative hypotheses may be written in sentences or stated as equations or inequalities. The test statistic for a goodness-of-fit test is given as... https://www.jove.com/v/13600 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13601.jpg Expected Frequencies in Goodness-of-Fit Tests A goodness-of-fit test is conducted to determine whether the observed frequency values are statistically similar to the frequencies expected for the dataset. Suppose the expected frequencies for a dataset are equal such as when predicting the frequency of any number appearing when casting a die. In that case, the expected frequency is the ratio of the total number of observations (n) to the number of categories (k). Hence, the expected frequency of any number appearing when casting a die will... https://www.jove.com/v/13601 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16484.jpg Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches Biopharmaceutical studies constitute a vital field aiming to enhance drug delivery methods and refine therapeutic approaches, drawing upon diverse interdisciplinary knowledge. In research methodologies, the choice between controlled and non-controlled studies significantly influences the study's reliability and accuracy. Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast, controlled... https://www.jove.com/v/16484 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62138.jpg Problem-Solving Before Instruction (PS-I): A Protocol for Assessment and Intervention in Students with Different Abilities This protocol guides researchers and educators through implementation of the Problem-Solving before Instruction approach (PS-I) in an undergraduate statistics class. It also describes an embedded experimental evaluation of this implementation, where the efficacy of PS-I is measured in terms of learning and motivation in students with different cognitive and affective predispositions. https://www.jove.com/v/62138 626 2021-09-11T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62506.jpg Validation of a Psychosocial Intervention on Body Image in Older People: An Experimental Design This experimental intervention examines the body satisfaction of older people. The aim is to compare a specific intervention with another general program and determine which is more effective for improving body satisfaction in people over fifty years old. https://www.jove.com/v/62506 460 2021-05-31T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63461.jpg A Psychophysics Paradigm for the Collection and Analysis of Similarity Judgments The protocol presents an experimental psychophysics paradigm to obtain large quantities of similarity judgments, and an accompanying analysis workflow. The paradigm probes context effects and enables modeling of similarity data in terms of Euclidean spaces of at least five dimensions. https://www.jove.com/v/63461 492 2022-03-01T21:45:00+00:00 JoVE no https://visualize.jove.com/16799771-a-sequential-injection-electronic-tongue-employing-the-transient-response-from-potentiometric-sensors-for-anion-multidetermination monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14551.jpg Potentiometry: Overview Potentiometry is an analytical technique that measures the potential difference between two electrodes in an electrochemical cell without drawing any significant current that could alter the solution's composition. This method employs an indicator electrode, which exchanges electrons with the analyte solution, and a reference electrode with a constant potential. Each electrode is immersed in a solution comprised of two half-cells. In a conventional setup, the reference electrode serves as the... https://www.jove.com/v/14551 66 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14553.jpg Potentiometry: Membrane Electrodes Membrane electrodes, also known as p-ion electrodes, use membranes that selectively interact with free analyte ions, generating a potential difference across the membrane. The resulting membrane potential, known as the asymmetry potential, is not zero even when analyte concentrations on both sides of the membrane are equal. The membrane's response is typically not selective to a single analyte but proportional to the concentration of all ions in the sample solution capable of interacting at the... https://www.jove.com/v/14553 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14557.jpg Potentiometric Titration: Overview Potentiometric titration is a quantitative analytical technique that determines the concentration of an analyte by measuring the potential difference between the two electrodes in the solution. The endpoint of a potentiometric titration is the point at which there is a significant change in the potential difference. It occurs when the stoichiometric reaction between the analyte and the titrant is complete. The endpoint is usually determined graphically by plotting the measured potential... https://www.jove.com/v/14557 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14591.jpg Mass Analyzers: Common Types The quadrupole mass analyzer consists of four cylindrical metal rods arranged in a diamond carrying a DC voltage and a radio-frequency AC voltage. The motion of ions through the quadrupole depends on the field strength, causing only ions of a certain m/z to resonate successfully and strike the detector at a given field strength. Though the transmission rate for these analyzers is high, the exact elemental composition of the sample is not determined because of low resolution; however, they are... https://www.jove.com/v/14591 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14792.jpg Gas Chromatography: Types of Detectors-II In gas chromatography, different detectors are employed to meet specific analytical needs. These detectors are often categorized based on their detection mechanisms and the types of compounds they are best suited to analyze. Thermal Conductivity Detectors (TCD), Flame Ionization Detectors (FID), and Electron Capture Detectors (ECD) represent common categories, each with unique operating principles and applications. However, beyond these, several other detectors are designed for more specialized... https://www.jove.com/v/14792 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14802.jpg Capillary Electrophoresis: Instrumentation Capillary electrophoresis instrumentation typically consists of several key components. A high-voltage power supply generates the electric field necessary for the separation by connecting to an anode (the positively charged electrode) and a cathode (the negatively charged electrode) located in buffer reservoirs at each end of the capillary tube. The system includes a sample vial, a fused silica capillary tube coated with polyimide for mechanical strength through which the sample components... https://www.jove.com/v/14802 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50020.jpg Multi-analyte Biochip (MAB) Based on All-solid-state Ion-selective Electrodes (ASSISE) for Physiological Research All-solid-state ion-selective electrodes (ASSISEs) constructed from a conductive polymer (CP) transducer provide several months of functional lifetime in liquid media. Here, we describe the fabrication and calibration process of ASSISEs in a lab-on-a-chip format. The ASSISE is demonstrated to have maintained a near-Nernstian slope profile after prolonged storage in complex biological media. https://www.jove.com/v/50020 483 2013-04-18T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51901.jpg Electronic Tongue Generating Continuous Recognition Patterns for Protein Analysis A novel approach is described for construction of electronic tongue (eT), which greatly simplifies the design and production of sensing materials, and allows the eT to generate continuous evolution profiles and landscapes for samples in liquid. The obtained eT is efficient for common protein analysis such as discrimination. https://www.jove.com/v/51901 526 2014-09-16T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68767.jpg TD-DFT Guided Advanced E-Eye Sensing Technique for On-site Quantification of Fe, Cr, F, and As in the Environmental, Biological, and Food Samples This work has discussed the protocol for designing and developing an E-Eye-Enable POCT device to detect Fe, Cr, As, and F in environmental samples, biological samples, and food and beverages. Nearly 2000 samples have been tested, and the results accord with the gold-standard technique. https://www.jove.com/v/68767 591 2025-09-19T20:50:00+00:00 JoVE no https://visualize.jove.com/16822042-circadian-rhythms-and-molecular-noise monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4234.jpg Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters Circadian clocks function within individual cells, i.e., they are cell-autonomous. Here, we describe methods for generating cell-autonomous clock models using non-invasive, luciferase-based real-time bioluminescence technology. Reporter cells provide tractable, functional model systems for studying circadian biology. https://www.jove.com/v/4234 638 2012-09-27T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11116.jpg Biological Clocks and Seasonal Responses The circadian—or biological—clock is an intrinsic, timekeeping, molecular mechanism that allows plants to coordinate physiological activities over 24-hour cycles called circadian rhythms. Photoperiodism is a collective term for the biological responses of plants to variations in the relative lengths of dark and light periods. The period of light-exposure is called the photoperiod. One example of photoperiodism in plants is seasonal flowering. Scientists believe that plants are cued to flower... https://www.jove.com/v/11116 165 2025-10-23T18:48:35+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11588.jpg Chromatin Structure Regulates pre-mRNA Processing In eukaryotic cells, nascent mRNA transcripts need to undergo many post-transcriptional modifications to reach the cell cytoplasm and translate into functional proteins. For a long time, transcription and pre-mRNA processing were considered two independent events that occur sequentially in the cell. However, it has now been well established that transcription and pre-mRNA processing are two simultaneous processes that are precisely regulated inside the cell. The chromatin structure, especially... https://www.jove.com/v/11588 161 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12000.jpg Circadian Rhythms and Gene Regulation The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent years,... https://www.jove.com/v/12000 139 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12157.jpg Non-equilibrium in the Cell An important concept in studying metabolism and energy is that of chemical equilibrium. Most chemical reactions are reversible. They can proceed in both directions, releasing energy into their environment in one direction, and absorbing it from the environment in the other direction. The same is true for the chemical reactions involved in cell metabolism, such as the breaking down and building up of proteins into and from individual amino acids, respectively. Reactants within a closed system... https://www.jove.com/v/12157 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12000.jpg Circadian Rhythms and Gene Regulation The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent years,... https://www.jove.com/v/13335 139 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16606.jpg Chronopharmacokinetics: Circadian Rhythms and Influence on Drug Response Circadian rhythms are cyclic changes that are crucial in plasma drug concentrations. Various standard circadian parameters, including core body temperature, heart rate, and other cardiovascular factors, directly impact disease states and the therapeutic response to drug therapy. The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of... https://www.jove.com/v/16606 75 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54673.jpg Parallel Measurement of Circadian Clock Gene Expression and Hormone Secretion in Human Primary Cell Cultures Here, we describe settings to monitor in parallel circadian bioluminescence and the secretory activity of human islet cells and primary myotubes. For this, we employed lentiviral gene delivery of a luciferase core clock reporter, followed by in vitro synchronization and collection of outflow medium by continuous cell perifusion. https://www.jove.com/v/54673 413 2016-11-11T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55832.jpg In Vitro Bioluminescence Assay to Characterize Circadian Rhythm in Mammary Epithelial Cells An in vitro bioluminescence assay to determine cellular circadian rhythm in mammary epithelial cells is presented. This method utilizes mammalian cell reporter plasmids expressing destabilized luciferase under the control of the PERIOD 2 gene promoter. It can be adapted to other cell types to evaluate organ-specific effects on circadian rhythm. https://www.jove.com/v/55832 716 2017-09-28T19:30:00+00:00 JoVE no https://visualize.jove.com/16829135-expression-purification-and-characterization-of-factor-ix-derivatives-using-a-novel-vector-system monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/59241.jpg Lentiviral Vector Platform for the Efficient Delivery of Epigenome-editing Tools into Human Induced Pluripotent Stem Cell-derived Disease Models Targeted DNA epigenome editing represents a powerful therapeutic approach. This protocol describes the production, purification, and concentration of all-in-one lentiviral vectors harboring the CRISPR-dCas9-DNMT3A transgene for epigenome-editing applications in human induced pluripotent stem cell (hiPSC)-derived neurons. https://www.jove.com/v/59241 827 2019-03-29T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62952.jpg Tail Vein Transection Bleeding Model in Fully Anesthetized Hemophilia A Mice The refined tail vein transection (TVT) bleeding model in anesthetized mice is a sensitive in vivo method for the assessment of hemophilic bleeding. This optimized TVT bleeding model uses blood loss and bleeding time as endpoints, refining other models and avoiding death as an endpoint. https://www.jove.com/v/62952 493 2021-09-30T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66320.jpg A Seamless Cloning Approach for Porcine Reproductive and Respiratory Syndrome Virus Expression Vector Construction Here, we present a protocol to obtain the pVAX1-PRRSV expression vector by introducing suitable restriction sites at the 3' end of the inserts. We can linearize the vector and join DNA fragments to the vector one by one through homologous recombination technology. https://www.jove.com/v/66320 258 2024-05-17T21:15:00+00:00 JoVE no https://visualize.jove.com/16845044-aspic-a-web-resource-for-alternative-splicing-prediction-and-transcript-isoforms-characterization monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10802.jpg RNA Splicing Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded... https://www.jove.com/v/10802 92 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10802.jpg RNA Splicing Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded... https://www.jove.com/v/11587 92 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11622.jpg Alternative RNA Splicing Alternative RNA splicing is the regulated splicing of exons and introns to produce different mature mRNAs from a single pre-mRNA. Unlike in constitutive splicing where a single gene produces a single type of mRNA, alternative splicing allows an organism to produce multiple proteins from a single gene and plays an important role in protein diversity. There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first... https://www.jove.com/v/11622 138 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12028.jpg Single Nucleotide Polymorphisms-SNPs A single nucleotide polymorphism or SNP is a single nucleotide variation at a specific genomic position in a large population. It is the most prevalent type of sequence variation found in the human genome. Point mutations that occur in more than 1% of the population qualify as SNPs. These are present once every 1000 nucleotides on an average in the human genome. Replacement of a purine with another purine (A/G) or a pyrimidine with another pyrimidine (C/T) is known as a transition. In contrast,... https://www.jove.com/v/12028 65 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10802.jpg Pre-mRNA Processing: RNA Splicing Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded... https://www.jove.com/v/12565 92 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11622.jpg Alternative RNA Splicing Alternative RNA splicing is the regulated splicing of exons and introns to produce different mature mRNAs from a single pre-mRNA. Unlike in constitutive splicing where a single gene produces a single type of mRNA, alternative splicing allows an organism to produce multiple proteins from a single gene and plays an important role in protein diversity. There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first... https://www.jove.com/v/12567 138 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54714.jpg Using RNA-sequencing to Detect Novel Splice Variants Related to Drug Resistance in In Vitro Cancer Models Here we describe a protocol aimed at investigating the impact of aberrant splicing on drug resistance in solid tumors and hematological malignancies. To this goal, we analyzed the transcriptomic profiles of parental and resistant in vitro models through RNA-seq and established a qRT-PCR based method to validate candidate genes. https://www.jove.com/v/54714 598 2016-12-09T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62181.jpg Using the E1A Minigene Tool to Study mRNA Splicing Changes This protocol presents a rapid and useful tool for evaluating the role of a protein with uncharacterized function in alternative splicing regulation after chemotherapeutic treatment. https://www.jove.com/v/62181 625 2021-04-22T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62636.jpg Identification of Alternative Splicing and Polyadenylation in RNA-seq Data Alternative splicing (AS) and alternative polyadenylation (APA) expand the diversity of transcript isoforms and their products. Here, we describe bioinformatic protocols to analyze bulk RNA-seq and 3' end sequencing assays to detect and visualize AS and APA varying across experimental conditions. https://www.jove.com/v/62636 515 2021-06-24T20:00:00+00:00 JoVE no https://visualize.jove.com/16845431-integrons-agents-of-bacterial-evolution monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3698.jpg Site-specific Bacterial Chromosome Engineering: ΦC31 Integrase Mediated Cassette Exchange (IMCE) A quick and efficient method to integrate foreign DNA of interest into pre-made acceptor strains, termed landing pad strains, is described. The method allows site-specific integration of a DNA cassette into the engineered landing pad locus of a given strain, through conjugation and expression of the ΦC31 integrase. https://www.jove.com/v/3698 501 2012-03-16T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11485.jpg Genome Size and the Evolution of New Genes While every living organism has a genome of some kind (be it RNA, or DNA), there is considerable variation in the sizes of these blueprints. One major factor that impacts genome size is whether the organism is prokaryotic or eukaryotic. In prokaryotes, the genome contains little to no non-coding sequence, such that genes are tightly clustered in groups or operons sequentially along the chromosome. Conversely, the genes in eukaryotes are punctuated by long stretches of non-coding sequence. https://www.jove.com/v/11485 201 JoVE no https://cloudfront.jove.com/files/ftp_upload/19543/19543_article_thumb_19543.jpg Mutations in Microorganisms Mutations are heritable changes in an organism’s genome involving alterations in the base sequence of DNA or RNA. These changes can influence cellular processes and phenotypic traits, potentially transforming the unaltered wild type into a mutant form. Such changes, termed forward mutations, are pivotal in shaping the genetic diversity of organisms.RNA viruses exhibit the highest mutation rates due to the absence of robust proofreading mechanisms during genome replication. In contrast,... https://www.jove.com/v/19543 78 2025-06-12T16:16:43+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19547/19547_article_thumb_19547.jpg Transposons Transposons, or "jumping genes," are small mobile genetic elements (MGEs) that range from 700 to 40,000 base pairs in length. They are found in all organisms and can move within the same chromosome or transfer to different chromosomes. In some cases, transposons can also jump between different host DNA molecules, such as plasmids or viruses, contributing to genetic variability.Barbara McClintock first discovered these mobile genetic elements in the 1940s while studying maize genetics, and she... https://www.jove.com/v/19547 84 2025-06-12T16:17:27+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40721/40721_article_thumb_40721.jpg Evolutionary Processes in Microbes Microbial evolution occurs rapidly due to short generation times and a variety of genetic processes, including horizontal gene transfer, mutation, recombination, and genetic drift. These mechanisms collectively enable microbes to adapt swiftly to changing environments.Horizontal gene transfer (HGT) allows genes to move between different species and occurs through three main mechanisms: conjugation, transformation, and transduction. Conjugation involves direct cell-to-cell contact for DNA... https://www.jove.com/v/40721 86 2026-03-12T20:57:33+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40722/40722_article_thumb_40722.jpg Evolution of New Traits in Microbes Microorganisms evolve rapidly due to their large population sizes and short generation times, often exhibiting measurable changes within days under laboratory conditions. Natural selection acts on standing genetic variation, enabling the retention and amplification of beneficial traits that confer fitness advantages in changing environments.Adaptive Pigment Regulation in RhodobacterIn Rhodobacter, a genus of purple non-sulfur bacteria, light-harvesting pigments such as bacteriochlorophyll and... https://www.jove.com/v/40722 84 2026-03-12T20:57:34+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40723/40723_article_thumb_40723.jpg Evolution of Microbial Genome Microbial genome evolution is a highly dynamic process shaped by continual gene gain and loss across species and strains. This genomic flexibility allows microorganisms to adapt rapidly to environmental pressures and interactions with other organisms. Central to understanding this diversity is the distinction between the core and pan genomes.The core genome comprises the genes shared by all sampled strains of a species, representing essential functions needed for fundamental cellular processes. https://www.jove.com/v/40723 68 2026-03-12T20:57:40+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52889.jpg Screening Foodstuffs for Class 1 Integrons and Gene Cassettes This protocol describes the detection of class 1 integrons and their associated gene cassettes in foodstuffs. https://www.jove.com/v/52889 577 2015-06-19T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57386.jpg Testing the Role of Multicopy Plasmids in the Evolution of Antibiotic Resistance Here we present an experimental method to test the role of multicopy plasmids in the evolution of antibiotic resistance. https://www.jove.com/v/57386 540 2018-05-02T21:00:00+00:00 JoVE no https://visualize.jove.com/16859144-cerebral-state-index-the-in-monitoring-and-evaluating-the-induction-of-anesthesia-with-target-controlled-infusion-of-propofol-in-adults monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13300.jpg Assessment of Diffusion and Perfusion Understanding and evaluating diffusion and perfusion is critical in assessing a patient's respiratory and circulatory health. These processes play key roles in maintaining the body's internal environment, ensuring that tissues receive adequate oxygen while waste products are efficiently removed. The Role of Diffusion in Respiration Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration. In the respiratory system, this principle... https://www.jove.com/v/13300 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15188.jpg General Anesthesia: Overview Anesthesia is a medical procedure that uses drugs for CNS suppression to enable painless surgeries and procedures. The selection of anesthetics is influenced by their pharmacokinetic properties, side effects, and patient characteristics. Various types of anesthesia include general, local, regional, spinal, and inhalational. General anesthesia induces unconsciousness in the whole body, while the others target specific areas or sensations. It is administered to minimize adverse effects, maintain... https://www.jove.com/v/15188 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15189.jpg Stages of General Anesthesia Various sedation levels offer significant advantages in facilitating procedural interventions for patients undergoing medical or invasive surgical procedures. These levels span from anxiolysis to general anesthesia, providing a spectrum of sedative effects to cater to specific patient needs. Anxiolysis reduces anxiety and is achieved through minimal sedation, enabling patients to remain awake and responsive while feeling more at ease during the procedure. This level can benefit minor... https://www.jove.com/v/15189 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15190.jpg Parenteral Anesthetics: Overview Intravenous anesthetics are drugs administered parenterally to induce anesthesia or sedation. Propofol is a widely used agent formulated as a 1% emulsion in soybean oil, glycerol, and egg phosphatide. It induces rapid anesthesia primarily due to its rapid distribution from the bloodstream to target tissues and is metabolized in the liver. However, it can cause significant pain on injection and hypertriglyceridemia. Fospropofol, a water-based prodrug of propofol, lacks these adverse effects. https://www.jove.com/v/15190 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15191.jpg Inhalational Anesthetics: Overview Inhalation anesthetics are drugs that induce general anesthesia upon inhalation. They work by increasing the sensitivity of GABAA receptors or inhibiting NMDA receptors, leading to a decrease in central nervous system activity. The depth of anesthesia can be rapidly adjusted by changing the concentration of the inhaled gas. Some common examples of inhalational anesthetics include volatile liquids like isoflurane, desflurane, sevoflurane and gases like xenon and nitrous oxide. Isoflurane, a... https://www.jove.com/v/15191 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53576.jpg Induction of an Isoelectric Brain State to Investigate the Impact of Endogenous Synaptic Activity on Neuronal Excitability In Vivo This procedure performs long-lasting in vivo intracellular recordings from single neurons during physiologically relevant cerebral states and after complete abolition of ongoing electrical activities, resulting in an isoelectric brain state. The physiological constants of the animal are carefully monitored during the transition to the artificial comatose condition. https://www.jove.com/v/53576 619 2016-03-31T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54739.jpg Drug-Induced Sleep Endoscopy (DISE) with Target Controlled Infusion (TCI) and Bispectral Analysis in Obstructive Sleep Apnea The aim of this study was to establish a standardized protocol for sleep endoscopy to differentiate obstruction patterns in obstructive sleep apnea (OSA). Target-controlled infusion (TCI) of the sedative was combined with real-time monitoring of the depth of sedation using bispectral analysis. https://www.jove.com/v/54739 474 2016-12-06T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56881.jpg Recording Brain Electromagnetic Activity During the Administration of the Gaseous Anesthetic Agents Xenon and Nitrous Oxide in Healthy Volunteers Simultaneous magnetoencephalography and electroencephalography provides a useful tool to search for common and distinct macro-scale mechanisms of reductions in consciousness induced by different anesthetics. This paper illustrates the empirical methods underlying the recording of such data from healthy humans during N-Methyl-D-Aspartate-(NMDA)-receptor-antagonist-based anesthesia during inhalation of nitrous oxide and xenon. https://www.jove.com/v/56881 892 2018-01-13T22:00:00+00:00 JoVE no https://visualize.jove.com/16860925-alternative-routes-and-mutational-robustness-in-complex-regulatory-networks monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4056.jpg Mapping Bacterial Functional Networks and Pathways in Escherichia Coli using Synthetic Genetic Arrays Systematic, large-scale synthetic genetic (gene-gene or epistasis) interaction screens can be used to explore genetic redundancy and pathway cross-talk. Here, we describe a high-throughput quantitative synthetic genetic array screening technology, termed eSGA that we developed for elucidating epistatic relationships and exploring genetic interaction networks in Escherichia coli. https://www.jove.com/v/4056 846 2012-11-12T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10791.jpg Mismatch Repair Overview Organisms are capable of detecting and fixing nucleotide mismatches that occur during DNA replication. This sophisticated process requires identifying the new strand and replacing the erroneous bases with correct nucleotides. Mismatch repair is coordinated by many proteins in both prokaryotes and eukaryotes. The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount... https://www.jove.com/v/10791 96 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11525.jpg Protein Networks An organism can have thousands of different proteins, and these proteins must cooperate to ensure the health of an organism. Proteins bind to other proteins and form complexes to carry out their functions. Many proteins interact with multiple other proteins creating a complex network of protein interactions. These interactions can be represented through maps depicting protein-protein interaction networks, represented as nodes and edges. Nodes are circles that are representative of a protein,... https://www.jove.com/v/11525 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13160.jpg Interactions Between Signaling Pathways Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli. Convergence and divergence, and cross-talk between signaling pathways Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response... https://www.jove.com/v/13160 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13201.jpg Mismatch Repair Organisms are capable of detecting and fixing nucleotide mismatches that occur during DNA replication. This sophisticated process requires identifying the new strand and replacing the erroneous bases with correct nucleotides. Mismatch repair is coordinated by many proteins in both prokaryotes and eukaryotes. The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic... https://www.jove.com/v/13201 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13949.jpg Regulation of Expression at Multiple Steps The gene expression in cells is regulated at different stages: (i) transcription, (ii) RNA processing, (iii) RNA localization, and (iv) translation. Transcriptional regulation is mediated by regulatory proteins such as transcription factors, activators, or repressors—these control gene expression by initiating or inhibiting the transcription of genes. Once a precursor or pre-mRNA is produced, it undergoes post-transcriptional modification, including 5' capping, splicing, and the addition of a... https://www.jove.com/v/13949 83 JoVE no https://cloudfront.jove.com/files/ftp_upload/19543/19543_article_thumb_19543.jpg Mutations in Microorganisms Mutations are heritable changes in an organism’s genome involving alterations in the base sequence of DNA or RNA. These changes can influence cellular processes and phenotypic traits, potentially transforming the unaltered wild type into a mutant form. Such changes, termed forward mutations, are pivotal in shaping the genetic diversity of organisms.RNA viruses exhibit the highest mutation rates due to the absence of robust proofreading mechanisms during genome replication. In contrast,... https://www.jove.com/v/19543 78 2025-06-12T16:16:43+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63084.jpg Inherent Dynamics Visualizer, an Interactive Application for Evaluating and Visualizing Outputs from a Gene Regulatory Network Inference Pipeline The Inherent Dynamics Visualizer is an interactive visualization package that connects to a gene regulatory network inference tool for enhanced, streamlined generation of functional network models. The visualizer can be used to make more informed decisions for parameterizing the inference tool, thus increasing confidence in the resulting models. https://www.jove.com/v/63084 644 2021-12-07T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64709.jpg Following the Dynamics of Structural Variants in Experimentally Evolved Populations We developed a cost-effective method to follow non-single nucleotide polymorphism allele dynamics that can easily be adapted to experimental evolution frozen archives. A triplet PCR technique was coupled with automated parallel capillary electrophoresis to quantify the relative frequency of an insertion allele over the course of experimental evolution. https://www.jove.com/v/64709 292 2023-02-03T21:35:00+00:00 JoVE no https://visualize.jove.com/16875138-a-new-information-technology-for-system-diagnosis-of-functional-activity-of-human-organs monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13865.jpg Magnetic Resonance Imaging Magnetic resonance imaging (MRI) is a noninvasive medical imaging technique based on a phenomenon of nuclear physics discovered in the 1930s, in which matter exposed to magnetic fields and radio waves was found to emit radio signals. In 1970, a physician and researcher named Raymond Damadian noticed that malignant (cancerous) tissue gave off different signals than normal body tissue. He applied for a patent for the first MRI scanning device in clinical use by the early 1980s. The early MRI... https://www.jove.com/v/13865 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16447.jpg Ultrasound II: Endoscopic Ultrasound and FibroScan Endoscopic Ultrasound (EUS) and FibroScan are valuable diagnostic tools in gastroenterology and hepatology, each with specific applications and techniques. Endoscopic Ultrasound (EUS): Technological Integration: EUS is a sophisticated integration of optical endoscopy and ultrasonography. The endoscope visualizes the mucosal surface directly, while the ultrasound component penetrates deeper to visualize organs and structures beyond the gastrointestinal wall. Image Formation: The ultrasound... https://www.jove.com/v/16447 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17752.jpg Brain Imaging Brain imaging technologies provide critical insights into both the structure and function of the human brain, enabling medical professionals and researchers to diagnose, study, and treat neurological disorders or psychiatric disorders more effectively. These technologies include computerized axial tomography (CAT or CT scans), positron-emission tomography (PET scans), magnetic resonance imaging (MRI), functional magnetic resonance imaging (fMRI), and Transcranial Magnetic Stimulation (TMS).<br... https://www.jove.com/v/17752 74 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51864.jpg Universal Hand-held Three-dimensional Optoacoustic Imaging Probe for Deep Tissue Human Angiography and Functional Preclinical Studies in Real Time We provide herein a detailed description of the experimental protocol for imaging with a newly developed hand-held optoacoustic (photoacoustic) system for three-dimensional functional and molecular imaging in real time. The demonstrated powerful performance and versatility may define new application areas of the optoacoustic technology in preclinical research and clinical practice. https://www.jove.com/v/51864 596 2014-11-04T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63883.jpg Multispectral Optoacoustic Tomography for Functional Imaging in Vascular Research The present protocol describes the acquisition of multispectral optoacoustic images of in vivo human skin vasculature. These include the quantification of hemoglobin and melanin, regarded as chromophores of interest for functional analysis. https://www.jove.com/v/63883 400 2022-06-08T21:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66243.jpg Using An In Vitro Tissue Perfusion System to Detect the Functional Activities of Isolated Intestinal Tubes in Real Time We present a method for isolating rat intestinal tubes and assessing the impact of drugs on their tension, frequency, and amplitude in vitro. This method offers a valuable approach for researchers investigating intestinal tubes. https://www.jove.com/v/66243 361 2024-07-26T19:40:00+00:00 JoVE no https://visualize.jove.com/16880669-apparent-increase-of-insulin-peak-area-in-hplc-analysis-of-a-preparation-consisting-of-a-mixture-of-insulin-and-total-parenteral-nutrition monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12220.jpg Insulin Secretory Vesicles Insulin secretory vesicles release insulin to stimulate blood glucose uptake and regulate carbohydrate metabolism. When the blood glucose levels increase, glucose enters the pancreatic β-islet cells through glucose transporters. Once inside, glucose is metabolized through glycolysis, the citric acid cycle, and the electron transport chain, producing ATP. This increase in ATP concentration closes ATP-sensitive potassium channels, leading to depolarization of the membrane and the opening of... https://www.jove.com/v/12220 65 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17297.jpg Insulin: Biosynthesis, Chemistry, and Preparation The endoplasmic reticulum (ER) of pancreatic β-cells synthesizes preproinsulin, which consists of a signal peptide, A and B chains, and a C-peptide. Preproinsulin is then cleaved and folded into proinsulin, which translocates to the Golgi apparatus for sorting and packaging into secretory granules. In these granules, enzymatic clipping generates insulin and C-peptide. Damage or functional impairment of β-cells inhibits insulin production, leading to diabetes. Diabetes treatment primarily uses... https://www.jove.com/v/17297 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17298.jpg Insulin Formulations: Types and Delivery Insulin preparations are categorized by their duration of action into short-acting and long-acting types. Two strategies are used to modify insulin's absorption and pharmacokinetic profile: slowing the absorption post-subcutaneous injection, or altering human insulin's amino acid sequence or protein structure. These changes retain the insulin's ability to bind to the insulin receptor, but alter its behavior in solution or after injection. Short-acting insulins are divided into rapid-acting... https://www.jove.com/v/17298 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17299.jpg Insulin: Dosing Regimen and Adverse Effects Insulin-replacement therapy usually includes both long-acting insulin (basal) and short-acting insulin (to cater to postprandial needs). In a diverse group of type 1 diabetes patients, the average daily insulin dose is typically 0.5-0.7 units/kg body weight. However, obese patients and pubertal adolescents may need more due to insulin resistance. The basal dose constitutes about 40%-50% of the total daily dose, with the rest as premeal insulin. The mealtime insulin dose should mirror... https://www.jove.com/v/17299 76 JoVE no https://cloudfront.jove.com/files/ftp_upload/40781/40781_article_thumb_40781.jpeg Production of Pharmaceuticals Industrial insulin production uses genetically engineered E. coli expressing a proinsulin gene controlled by a tryptophan promoter and containing a methionine linker for later cleavage. The cells also carry ampicillin resistance for selective growth. Seed cultures are stored at −80 °C and production begins by thawing a small amount to inoculate starter cultures, which are progressively scaled to a 50,000-L bioreactor. In the bioreactor, E. coli grow in nutrient-rich media under sterile, tightly... https://www.jove.com/v/40781 90 2026-03-12T20:36:06+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57531.jpg Homogeneous Time-resolved Förster Resonance Energy Transfer-based Assay for Detection of Insulin Secretion Here, we present homogeneous time resolved FRET (HTRF) as an efficient method for rapid detection of insulin secreted from cells. https://www.jove.com/v/57531 450 2018-05-10T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64840.jpg Differentiation of Human Pluripotent Stem Cells into Insulin-Producing Islet Clusters The differentiation of stem cells into islet cells provides an alternative solution to conventional diabetes treatment and disease modeling. We describe a detailed stem cell culture protocol that combines a commercial differentiation kit with a previously validated method to aid in producing insulin-secreting, stem cell-derived islets in a dish. https://www.jove.com/v/64840 521 2023-06-23T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66730.jpg Assessing Insulin Clearance in Mice via In Situ Liver Perfusion Hepatic insulin clearance is critical for regulating glucose homeostasis. This article describes a user-friendly hepatic perfusion procedure for directly evaluating the hepatic insulin clearance rate in situ in mice. https://www.jove.com/v/66730 450 2024-12-13T20:00:00+00:00 JoVE no https://visualize.jove.com/16880840-synthesis-of-an-arbitrary-abcd-system-with-fixed-lens-positions monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14289.jpg Space Trusses: Problem Solving A space truss is a three-dimensional counterpart of a planar truss. These structures consist of members connected at their ends, often utilizing ball-and-socket joints to create a stable and versatile framework. Due to its adaptability and capacity to withstand complex loads, the space truss is widely used in various construction projects. Consider a tripod consisting of a tetrahedral space truss with a ball-and-socket joint at C. Suppose the height and lengths of the horizontal and vertical... https://www.jove.com/v/14289 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15540.jpg Relative Motion Analysis using Rotating Axes Consider a component AB undergoing a linear motion. Along with a linear motion, point B also rotates around point A. To comprehend this complex movement, position vectors for both points A and B are established using a stationary reference frame. However, to express the relative position of point B relative to point A, an additional frame of reference, denoted as x'y', is necessary. This additional frame not only translates but also rotates relative to the fixed frame, making it instrumental in... https://www.jove.com/v/15540 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15609.jpg Relative Motion Analysis - Acceleration A slider-crank mechanism converts rotational motion from the crank into linear motion of the slider or vice versa. This mechanism consists of three main parts: the crank, the connecting rod, and the slider. The movement of the slider-crank is an example of general plane motion as the fluctuating angle between the crank and the connecting rod. Consider a segment AB where point A is at the end of the slider and point B is on the diametrically opposite end to point A, on a crack. The variance in... https://www.jove.com/v/15609 70 JoVE no https://cloudfront.jove.com/files/ftp_upload/15846/15846_article_thumb_15846.png The Seven Crystal Systems: Overview Crystals with various point group symmetries belong to different crystal classes, which are synonymous terms. Despite being in the same class, crystals may have distinct shapes, like cubes and octahedra. There are 32 three-dimensional point groups, all of which are systematically divided into seven crystal systems.The basic cubic crystal system, exemplified by NaCl, features orthogonal vectors (α = β = �� = 90°) of equal lengths (a = b = c). When specific requirements are not imposed on the... https://www.jove.com/v/15846 84 2026-02-26T21:04:40+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16146.jpg Transmission-Line Differential Equations Transmission lines are essential components of electrical power systems. They are characterized by the distributed nature of resistance (R), inductance (L), and capacitance (C) per unit length. To analyze these lines, differential equations are employed to model the variations in voltage and current along the line. Line Section Model A circuit representing a line section of length Δx helps in understanding the transmission line parameters. The voltage V(x) and current i(x) are measured from the... https://www.jove.com/v/16146 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/41037/41037_article_thumb_41037_TN.jpg Geometry of Hyperbolas A hyperbola consists of all points where the absolute difference of distances to two fixed points, called foci, remains constant. The standard equation isEach branch extends infinitely and approaches two asymptotes, which guide the curve’s behavior. The parameters a and b define key features: a measures the distance from the center to each vertex along the transverse axis, while b influences the slopes of the asymptotes. The asymptotes have equationsA rectangle centered at the origin with... https://www.jove.com/v/41037 90 2025-11-26T13:44:05+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51148.jpg Time Multiplexing Super Resolving Technique for Imaging from a Moving Platform A method for overcoming the optical diffraction limit is presented. The method includes a two-step process: optical phase retrieval using iterative Gerchberg-Saxton algorithm, and imaging system shifting followed by repetition of the first step. A synthetically increased lens aperture is generated along the direction of movement, yielding higher imaging resolution. https://www.jove.com/v/51148 385 2014-02-13T06:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53988.jpg A Guide to Structured Illumination TIRF Microscopy at High Speed with Multiple Colors This article provides an in depth guide for the assembly and operation of a structured illumination microscope operating with total internal reflection fluorescence illumination (TIRF-SIM) to image dynamic biological processes with optical super-resolution in multiple colors. https://www.jove.com/v/53988 675 2016-05-30T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65411.jpg Design and Building of a Customizable, Single-Objective, Light-Sheet Fluorescence Microscope for the Visualization of Cytoskeleton Networks This protocol describes in detail how to build a single-objective, light-sheet fluorescence microscope and its usage for visualizing cytoskeleton networks. https://www.jove.com/v/65411 512 2024-01-26T20:50:00+00:00 JoVE no https://visualize.jove.com/16898153-distributed-microbial-state-effects-on-competition-in-enhanced-biological-phosphorus-removal-systems monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/19464/19464_article_thumb_19464.jpg Environmental Applications of Microorganisms Microorganisms play a pivotal role in maintaining ecosystem balance by recycling essential elements such as carbon, nitrogen, and phosphorus, as well as supporting processes like bioremediation, wastewater treatment, and biofuel production.Microbes in Elemental CyclesIn the carbon cycle, microorganisms decompose organic matter, releasing carbon dioxide via aerobic respiration. This carbon dioxide is subsequently used by photosynthetic organisms to synthesize organic compounds, closing the... https://www.jove.com/v/19464 90 2025-06-12T16:27:26+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40730/40730_article_thumb_40730.jpg Microenvironments Microorganisms inhabit highly localized spaces known as microenvironments, which are defined by distinct physical and chemical characteristics. These include oxygen concentration, pH, temperature, light availability, and nutrient levels. The conditions within a microenvironment can differ markedly from those in the surrounding area and significantly influence microbial growth, metabolism, and community structure.Microenvironments often display sharp physicochemical gradients over small spatial... https://www.jove.com/v/40730 82 2026-03-12T20:57:23+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40735/40735_article_thumb_40735.jpg Microbial Interactions: Competition Microbial competition is an ecological interaction in which microorganisms vie for limited resources within shared environments. These resources may include nutrients, space, or light, depending on the system. The intensity and outcome of competition are influenced by the environmental context, such as nutrient availability, spatial constraints, and the diversity of microbial species present. These competitive interactions significantly influence the structure, function, and resilience of... https://www.jove.com/v/40735 86 2026-03-12T20:57:44+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40743/40743_article_thumb_40743.jpg Marine Microbial Ecology Marine microbial ecosystems are shaped by distinct physicochemical limits, including high salinity, low nutrient availability, and fluctuating oxygen levels. These conditions favor smaller microbial cell sizes, which maximize their surface-to-volume ratio for efficient nutrient uptake.Microbial activity and community composition are closely linked to biogeochemical cycles, particularly in dynamic environments like estuaries, where halotolerant microbes thrive in response to variable salinity... https://www.jove.com/v/40743 90 2026-03-12T20:57:29+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40745/40745_article_thumb_40745.jpg Freshwater Microbial Ecology Freshwater systems such as streams, rivers, and lakes exhibit distinct physical and biological characteristics that influence their microbial communities. These environments are broadly categorized into lotic systems—those with flowing waters like streams and most rivers—and lentic systems, which include still or slow-moving waters such as lakes, ponds, and marshes.In lentic systems, phytoplankton drive primary production, generating autochthonous organic carbon. In contrast, lotic systems... https://www.jove.com/v/40745 84 2026-03-12T20:57:36+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40752/40752_article_thumb_40752.jpg Microbial Wastewater Treatment Microbial communities in aquatic ecosystems play a key role in the natural breakdown of contaminants introduced through domestic and industrial effluents. Acting as biological catalysts, these microbes change and mineralize a wide range of organic and inorganic pollutants under different redox conditions.In oxygen-rich surface waters, aerobic heterotrophs lead organic matter breakdown, using oxygen as the terminal electron acceptor to efficiently oxidize substrates to carbon dioxide and water. https://www.jove.com/v/40752 90 2026-05-20T18:06:58+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53443.jpg A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities A novel reactor design, coined a high density bioreactor (HDBR), is presented for the cultivation and study of high density microbial communities. Here, the HDBR is successfully applied in a photobioreactor (PBR) configuration for the study of nitrogen metabolism by a mixed high density algal community. https://www.jove.com/v/53443 493 2015-12-25T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55256.jpg Comparison of Scale in a Photosynthetic Reactor System for Algal Remediation of Wastewater An experimental methodology is presented to compare the performance of small (100 L) and large (1,000 L) scale reactors designed for algae remediation of landfill wastewater. System characteristics, including surface area to volume ratio, retention time, biomass density, and wastewater feed concentrations, can be adjusted based on application. https://www.jove.com/v/55256 340 2017-03-06T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60072.jpg Measuring Phosphorus Release in Laboratory Microcosms for Water Quality Assessment Accurate quantification of phosphorus (P) desorption potential in saturated soils and sediments is important for P modeling and transport mitigation efforts. To better account for in situ soil-water redox dynamics and P mobilization under prolonged saturation, a simple approach was developed based on repeated sampling of laboratory microcosms. https://www.jove.com/v/60072 402 2019-07-22T22:00:00+00:00 JoVE no https://visualize.jove.com/16913220-bacterial-cis-regulatory-rna-structures monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10800.jpg Types of RNA Overview Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use. RNA... https://www.jove.com/v/10800 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11579.jpg Bacterial RNA Polymerase Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity. In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize... https://www.jove.com/v/11579 43 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11607.jpg Cis-regulatory Sequences Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are... https://www.jove.com/v/11607 122 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12557.jpg Types of RNA Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in regulating gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use. RNA Performs Diverse... https://www.jove.com/v/12557 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11607.jpg Cis-regulatory Sequences Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are... https://www.jove.com/v/13143 122 JoVE no https://cloudfront.jove.com/files/ftp_upload/19536/19536_article_thumb_19536.jpg Translational Regulation Translational regulation in prokaryotes ensures efficient protein synthesis by controlling ribosome access to mRNA. This regulation is mediated by secondary RNA structures, including translational riboswitches, RNA thermometers, and small RNAs (sRNAs), which respond to intracellular and environmental signals to modulate gene expression.Translational RiboswitchesRiboswitches in the leader region of mRNAs can regulate translation by altering the accessibility of the Shine-Dalgarno (SD) sequence,... https://www.jove.com/v/19536 89 2025-06-12T16:14:54+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59611.jpg An Assay for Quantifying Protein-RNA Binding in Bacteria In this method, we quantify the binding affinity of RNA binding proteins (RBPs) to cognate and non-cognate binding sites using a simple, live, reporter assay in bacterial cells. The assay is based on repression of a reporter gene. https://www.jove.com/v/59611 422 2019-06-12T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61731.jpg MS2-Affinity Purification Coupled with RNA Sequencing in Gram-Positive Bacteria MAPS technology has been developed to scrutinize the targetome of a specific regulatory RNA in vivo. The sRNA of interest is tagged with a MS2 aptamer enabling the co-purification of its RNA partners and their identification by RNA sequencing. This modified protocol is particularly suited for Gram-positive... https://www.jove.com/v/61731 514 2021-02-23T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61808.jpg A Non-Coding Small RNA MicC Contributes to Virulence in Outer Membrane Proteins in Salmonella Enteritidis An λ-Red-mediated recombination system was used to create a deletion mutant of a small non-coding RNA micC. https://www.jove.com/v/61808 390 2021-01-27T22:00:00+00:00 JoVE no https://visualize.jove.com/16956888-rna-editing-by-adar2-is-metabolically-regulated-in-pancreatic-islets-and-beta-cells monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4080.jpg Assessing Replication and Beta Cell Function in Adenovirally-transduced Isolated Rodent Islets This protocol allows one to identify factors that modulate functional beta cell mass to find potential therapeutic targets for the treatment of diabetes. The protocol consists of a streamlined method to assess islet replication and beta cell function in isolated rat islets following manipulation of gene expression with adenoviruses. https://www.jove.com/v/4080 571 2012-06-25T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11605.jpg Cell Specific Gene Expression Multicellular organisms contain a variety of structurally and functionally distinct cell types, but the DNA in all the cells originated from the same parent cells. The differences in the cells can be attributed to the differential gene expression. Liver cells, whose functions include detoxification of blood, production of bile to metabolize fats, and synthesis of proteins essential for metabolism, must express a specific set of genes to perform their functions. Gene expression also varies with... https://www.jove.com/v/11605 118 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11623.jpg RNA Editing RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or modification. The extent of RNA editing varies from a few hundred bases, in mitochondrial DNA of trypanosomes, to a just single base, in nuclear genes of mammals. Even a single base change in the pre-mRNA can convert a codon for one amino acid into the codon for another amino acid or a stop codon. This type of re-coding can significantly affect the... https://www.jove.com/v/11623 143 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12220.jpg Insulin Secretory Vesicles Insulin secretory vesicles release insulin to stimulate blood glucose uptake and regulate carbohydrate metabolism. When the blood glucose levels increase, glucose enters the pancreatic β-islet cells through glucose transporters. Once inside, glucose is metabolized through glycolysis, the citric acid cycle, and the electron transport chain, producing ATP. This increase in ATP concentration closes ATP-sensitive potassium channels, leading to depolarization of the membrane and the opening of... https://www.jove.com/v/12220 65 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14992.jpg Hormones Regulating Blood Glucose Insulin is released by beta cells of the pancreas when blood glucose levels are high. It facilitates glucose absorption and utilization in insulin-dependent cells with insulin receptors on their plasma membranes. Insulin promotes glucose uptake by increasing the number of glucose transport proteins in the cell membrane, allowing glucose to enter the cell. As a result, glucose utilization and ATP production are enhanced. In addition to accelerating glucose uptake and utilization, insulin has... https://www.jove.com/v/14992 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17292.jpg Glucose Homeostasis: Pancreatic Islets and Insulin Secretion The pancreatic islets comprising only 1%-2% of the volume are highly vascularized and innervated mini-organs. They contain five endocrine cell types, including β cells that secrete insulin, which is synthesized as a single polypeptide chain, preproinsulin, processed to proinsulin, and finally to insulin and C-peptide. This process is complex and regulated, involving the Golgi complex, the endoplasmic reticulum, and the secretory granules of the β cell. Insulin and C-peptide are co-secreted in... https://www.jove.com/v/17292 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17297.jpg Insulin: Biosynthesis, Chemistry, and Preparation The endoplasmic reticulum (ER) of pancreatic β-cells synthesizes preproinsulin, which consists of a signal peptide, A and B chains, and a C-peptide. Preproinsulin is then cleaved and folded into proinsulin, which translocates to the Golgi apparatus for sorting and packaging into secretory granules. In these granules, enzymatic clipping generates insulin and C-peptide. Damage or functional impairment of β-cells inhibits insulin production, leading to diabetes. Diabetes treatment primarily uses... https://www.jove.com/v/17297 85 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54298.jpg A High-content In Vitro Pancreatic Islet β-cell Replication Discovery Platform Critical challenges for the diabetes research field are to understand the molecular mechanisms that regulate islet β-cell replication and to develop methods for stimulating β-cell regeneration. Herein a high-content screening method to identify and assess the β-cell replication-promoting activity of small molecules is presented. https://www.jove.com/v/54298 575 2016-07-16T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59866.jpg Single-cell RNA Sequencing and Analysis of Human Pancreatic Islets Here, we present a protocol to generate high-quality, large-scale transcriptome data of single cells from isolated human pancreatic islets using a droplet-based microfluidic single-cell RNA sequencing technology. https://www.jove.com/v/59866 694 2019-07-18T21:00:00+00:00 JoVE no https://visualize.jove.com/16981968-neural-network-technology-to-predict-intracellular-water-volume monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12173.jpg Aquaporins Aquaporins or AQPs are a family of integral membrane proteins whose primary function is to transport water, while some called aquaglyceroporins also transport glycerol. In addition, aquaporins have also been suspected to be involved in transporting volatile substances, such as carbon dioxide and ammonia, across membranes. Such AQPs that act as gas channels are often highly expressed in cells involved in the gaseous exchange, such as red blood cells, epithelial cells, and pulmonary capillaries.<br... https://www.jove.com/v/12173 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16266.jpg Body Water Content and Fluid Compartments Life's biochemical processes occur within aqueous solutions. Solutes are substances that are dissolved within these solutions. The human body contains a variety of solutes, which can differ across various body parts. These can encompass proteins—such as those responsible for clotting and carbohydrate transport—as well as electrolytes. In medicine, an electrolyte is often described as a mineral ion derived from a salt possessing an electric charge. Examples include sodium ions (Na+) and chloride... https://www.jove.com/v/16266 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16269.jpg Regulation of Water Intake Osmolality refers to the number of solute particles per kilogram of solvent in a solution. Plasma osmolality specifically indicates the total number of solute particles per kilogram of water in blood plasma. This value reflects the body's hydration status and is tightly regulated through mechanisms controlling water intake and output. While water consumption is a conscious decision, the body has intrinsic regulatory systems to maintain fluid balance. Dehydration, a state of water deficit... https://www.jove.com/v/16269 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16270.jpg Regulation of Water Output The human body predominantly expels water through the urinary system. On average, an individual generates around 1.5 liters of urine each day. This amount can fluctuate based on how well a person is hydrated, but a critical minimum quantity of urine must be produced to ensure the body's proper functioning. Daily, the kidneys remove 600 to 1200 milliosmoles of dissolved substances, effectively excreting excess minerals and water-soluble toxins such as creatinine, urea, and uric acid from the... https://www.jove.com/v/16270 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/40937/40937_article_thumb_40937.jpg Cerebral Edema l: Introduction Cerebral edema is a pathological increase in brain water content that disrupts intracranial pressure regulation and impairs neurological function. Because the cranial vault is rigid, even modest increases in tissue volume can compromise cerebral perfusion, distort neural structures, and initiate secondary injury. Cerebral edema develops through four principal mechanisms: vasogenic, cytotoxic, interstitial, and ionic.Vasogenic EdemaVasogenic edema arises from disruption of the blood–brain... https://www.jove.com/v/40937 79 2026-04-13T23:56:01+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55755.jpg Real-time Iontophoresis with Tetramethylammonium to Quantify Volume Fraction and Tortuosity of Brain Extracellular Space This protocol describes real-time iontophoresis, a method that measures physical parameters of the extracellular space (ECS) of living brains. The diffusion of an inert molecule released into the ECS is used to calculate the ECS volume fraction and tortuosity. It is ideal for studying acute reversible changes to brain ECS. https://www.jove.com/v/55755 645 2017-07-24T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56923.jpg High-resolution Volume Imaging of Neurons by the Use of Fluorescence eXclusion Method and Dedicated Microfluidic Devices Volume is an important parameter regarding physiological and pathological characteristics of cells. We describe a fluorescent exclusion method allowing full-field measurement of in vitro neuronal volume with sub-micrometric axial resolution required for the analysis of neurites and dynamic structures implied in neuronal growth. https://www.jove.com/v/56923 551 2018-03-26T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63792.jpg Computational Modeling of Retinal Neurons for Visual Prosthesis Research - Fundamental Approaches We summarize a workflow to computationally model a retinal neuron's behaviors in response to electrical stimulation. The computational model is versatile and includes automation steps that are useful in simulating a range of physiological scenarios and anticipating the outcomes of future in vivo/in vitro studies. https://www.jove.com/v/63792 650 2022-06-21T20:00:00+00:00 JoVE no https://visualize.jove.com/16986254-new-analysis-technique-for-multistability-detection monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1935.jpg Rapid Homogeneous Detection of Biological Assays Using Magnetic Modulation Biosensing System Magnetic modulation biosensing system is utilized to rapidly, sensitively and simply detect biological assays, such as DNA molecules and proteins. https://www.jove.com/v/1935 418 2010-06-14T00:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14360.jpg Stability of Equilibrium Configuration Understanding the stability of equilibrium configurations is a fundamental part of mechanical engineering. In any system, there are three distinct types of equilibrium: stable, neutral, and unstable. A stable equilibrium occurs when a system tends to return to its original position when given a small displacement, and the potential energy is at its minimum. An example of a stable equilibrium is when a cantilever beam is fixed at one end and a weight is attached to the other end. If the weight... https://www.jove.com/v/14360 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14362.jpg Stability of Equilibrium Configuration: Problem Solving The stability of equilibrium configurations is an important concept in physics, engineering, and other related fields. In simple terms, it refers to the tendency of an object or system to return to its equilibrium position after being disturbed. The stability of an equilibrium configuration can be analyzed by considering the potential energy function of the system and examining its behavior near the equilibrium point. Problem-solving in the context of the stability of equilibrium configuration... https://www.jove.com/v/14362 73 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16053.jpg BIBO stability of continuous and discrete -time systems System stability is a fundamental concept in signal processing, often assessed using convolution. For a system to be considered bounded-input bounded-output (BIBO) stable, any bounded input signal must produce a bounded output signal. A bounded input signal is one where the modulus does not exceed a certain constant at any point in time. To determine the BIBO stability, the convolution integral is utilized when a bounded continuous-time input is applied to a Linear Time-Invariant (LTI) system. https://www.jove.com/v/16053 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16107.jpg Multi-input and Multi-variable systems Cruise control systems in cars are designed as multi-input systems to maintain a driver's desired speed while compensating for external disturbances such as changes in terrain. The block diagram for a cruise control system typically includes two main inputs: the desired speed set by the driver and any external disturbances, such as the incline of the road. By adjusting the engine throttle, the system maintains the vehicle's speed as close to the desired value as possible. In the absence of... https://www.jove.com/v/16107 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16115.jpg Stability The time response of a linear time-invariant (LTI) system can be divided into transient and steady-state responses. The transient response represents the system's initial reaction to a change in input and diminishes to zero over time. In contrast, the steady-state response is the behavior that persists after the transient effects have faded. The stability of an LTI system is determined by the roots of its characteristic equation, known as poles. A system is stable if it produces a bounded... https://www.jove.com/v/16115 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16170.jpg Multimachine Stability Multimachine stability analysis is crucial for understanding the dynamics and stability of power systems with multiple synchronous machines. The objective is to solve the swing equations for a network of M machines connected to an N-bus power system. In analyzing the system, the nodal equations represent the relationship between bus voltages, machine voltages, and machine currents. The nodal equation is given by: V is the N-vector of bus voltages, E is the M-vector of machine voltages, I is... https://www.jove.com/v/16170 85 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65042.jpg Automated Multimodal Stimulation and Simultaneous Neuronal Recording from Multiple Small Organisms We present a method for the flexible chemical and multimodal stimulation and recording of simultaneous neural activity from many Caenorhabditis elegans worms. This method uses microfluidics, open-source hardware and software, and supervised automated data analysis to enable the measurement of neuronal phenomena such as adaptation, temporal inhibition, and stimulus crosstalk. https://www.jove.com/v/65042 508 2023-03-03T22:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66129.jpg Quantitative Analysis of Mitochondria-Associated Endoplasmic Reticulum Membrane (MAM) Stabilization in a Neural Model of Alzheimer's Disease (AD) Here, we describe measuring the axonal transport rate of constitutive stabilizers of mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs) by increasing or maintaining neurotoxic β-amyloid (Aβ) generation from Alzheimer's disease (AD) neurons in real-time to serve as a direct and quantitative metric to measure MAM stabilization and aid the development of AD therapeutics. https://www.jove.com/v/66129 401 2025-01-10T20:00:00+00:00 JoVE no https://visualize.jove.com/17008255-cognitive-task-load-in-a-naval-ship-control-centre-from-identification-to-prediction monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14280.jpg Distributed Loads: Problem Solving Beams are structural elements commonly employed in engineering applications requiring different load-carrying capacities. The first step in analyzing a beam under a distributed load is to simplify the problem by dividing the load into smaller regions, which allows one to consider each region separately and calculate the magnitude of the equivalent resultant load acting on each portion of the beam. The magnitude of the equivalent resultant load for each region can be determined by calculating... https://www.jove.com/v/14280 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16107.jpg Multi-input and Multi-variable systems Cruise control systems in cars are designed as multi-input systems to maintain a driver's desired speed while compensating for external disturbances such as changes in terrain. The block diagram for a cruise control system typically includes two main inputs: the desired speed set by the driver and any external disturbances, such as the incline of the road. By adjusting the engine throttle, the system maintains the vehicle's speed as close to the desired value as possible. In the absence of... https://www.jove.com/v/16107 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18172.jpg Working Memory Working memory refers to a combination of components, including short-term memory and attention, that allow an individual to hold information temporarily as we perform cognitive tasks. It is an essential cognitive function that enables the execution of complex tasks such as problem-solving, comprehension, and reasoning. Unlike short-term memory, which simply involves the storage of information for a brief period, working memory involves the active manipulation and processing of this information. https://www.jove.com/v/18172 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52286.jpg Practical Methodology of Cognitive Tasks Within a Navigational Assessment Children who have complex communication needs can benefit from the use of a speech-generating device (SGD). Cognitive skills were identified as having an impact on the ability to navigate between levels of SGDs. This protocol describes the steps needed for Speech-language Pathologists to assess cognitive skills and navigational abilities. https://www.jove.com/v/52286 319 2015-06-01T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66886.jpg Eye Tracking During A Complex Aviation Task For Insights Into Information Processing Eye tracking is a non-invasive method to probe information processing. This article describes how eye tracking can be used to study gaze behavior during a flight simulation emergency task in low-time pilots (i.e., <350 flight hours). https://www.jove.com/v/66886 468 2025-04-04T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/69621.jpg Estimate the Cognitive Load Using Electrocardiographic Measure: A Human-AI Collaborative Task This protocol describes the use of physiological indicators to measure variations in cognitive load across different task difficulty levels in human-AI collaborative tasks. The findings suggest that people adapt their decision-making processes according to task difficulty, thereby reflecting different levels of cognitive load. https://www.jove.com/v/69621 428 2025-12-05T22:45:00+00:00 JoVE no https://visualize.jove.com/17123608-intraocular-lens-exchange-due-to-incorrect-lens-power monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14480.jpg Glaucoma: Overview Glaucoma is an eye condition characterized by increased intraocular pressure that damages the retina and optic nerve, leading to irreversible blindness if left untreated. The human eye has various components, including the cornea, iris, pupil, lens, and optic nerve. Aqueous humor is secreted by the epithelium of the ciliary body in the posterior chamber and flows through the trabecular meshwork and canal of Schlemm, maintaining normal intraocular pressure. The trabecular meshwork and the canal... https://www.jove.com/v/14480 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14481.jpg Open Angle Glaucoma: Treatment In open-angle glaucoma, the iridocorneal angle remains open, but the trabecular meshwork becomes stiff, slowing down the outflow of aqueous humor. This causes a buildup of aqueous humor in the anterior chamber, leading to a sudden increase in intraocular pressure. The treatment for open-angle glaucoma focuses on reducing the elevated intraocular pressure by either decreasing the secretion of aqueous humor or increasing its outflow. Drugs such as carbonic anhydrase inhibitors, α2- and... https://www.jove.com/v/14481 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14482.jpg Angle Closure Glaucoma: Treatment Angle-closure glaucoma, or closed-angle glaucoma, is an eye condition where the iris bulges out and blocks the iridocorneal angle, resulting in a buildup of aqueous humor and increased intraocular pressure. Immediate medical attention is necessary due to the sudden onset of symptoms. The treatment for angle-closure glaucoma includes short-term and long-term approaches. Short-term treatment involves using eye drops like pilocarpine to lower intraocular pressure by increasing aqueous humor... https://www.jove.com/v/14482 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14963.jpg Focusing of Light in the Eye Light rays enter the eye through the cornea, a transparent dome-shaped tissue that is the eye's outermost layer. The cornea bends or refracts, light rays traveling to the pupil. The shape of the cornea determines how much of the light is bent and whether the image will be focused correctly on the retina at the back of the eye. Once the light has passed through both refraction layers, it converges into a single focal point onto a small area. This is where photoreceptors start transforming... https://www.jove.com/v/14963 76 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58590.jpg Synthesis of Soft Polysiloxane-urea Elastomers for Intraocular Lens Application This study describes synthetic routes for aminopropyl-terminated polydimethylsiloxanes and polydimethyl-methyl-phenyl-siloxane-block copolymers and for soft polysiloxane-based urea (PSU) elastomers. It presents the application of PSUs as accommodating an intraocular lens. An evaluation method for in vitro cytotoxicity is also described. https://www.jove.com/v/58590 709 2019-03-08T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65419.jpg Rotating the Intraocular Lens to Prevent Posterior Capsular Opacification in Cataract Surgeries The present protocol describes removing residual epithelial cells by rotating the intraocular lens in extracapsular cataract surgery without extra tools for preventing posterior capsular opacification. https://www.jove.com/v/65419 299 2023-07-07T21:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67173.jpg Correction of Presbyopia by Monocular Bi-Aspheric Ablation Profile This article provides a step-by-step guide to correcting presbyopia with a monocular bi-aspheric ablation profile. https://www.jove.com/v/67173 346 2024-09-20T20:50:00+00:00 JoVE no https://visualize.jove.com/17132030-modelling-the-costs-and-outcomes-of-changing-rates-of-screening-for-alcohol-misuse-by-gps-in-the-australian-context monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/57027.jpg Murine Drinking Models in the Development of Pharmacotherapies for Alcoholism: Drinking in the Dark and Two-bottle Choice Alcohol Use Disorder (AUD) is a major national health problem and the development of more effective treatments is required to offset the needs of this patient population. To this end, the following protocol utilizes two simple rodent drinking models to assess the preclinical efficacy of lead anti-alcohol compounds. https://www.jove.com/v/57027 451 2019-01-07T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60794.jpg Implementation of a Real-Time Psychosis Risk Detection and Alerting System Based on Electronic Health Records using CogStack We demonstrate how to deploy a real-time psychosis risk calculation and alerting system based on CogStack, an information retrieval and extraction platform for electronic health records. https://www.jove.com/v/60794 451 2020-05-15T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63576.jpg The Motivation for Alcohol Reward: Predictors of Progressive-Ratio Intravenous Alcohol Self-Administration in Humans This study aims to show that the Progressive-Ratio Computer-assisted Alcohol-Infusion System (CAIS) paradigm is a reliable and sensitive method that can be used to examine the motivating properties associated with alcohol self-administration in humans. https://www.jove.com/v/63576 340 2022-04-28T19:40:00+00:00 JoVE no https://visualize.jove.com/17156848-application-and-comparison-of-classification-algorithms-for-recognition-of-alzheimers-disease-in-electrical-brain-activity-eeg monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2715.jpg Examining the Characteristics of Episodic Memory using Event-related Potentials in Patients with Alzheimer's Disease The methodology for collecting high-density event-related potential data while patients with Alzheimer's disease perform a recognition memory task is reviewed. This protocol will include subject preparation, quality assurance, data acquisition, and data analysis. https://www.jove.com/v/2715 661 2011-08-30T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60249.jpg Statistical Modelling of Cortical Connectivity Using Non-invasive Electroencephalograms Standard EEG analysis techniques offer limited insight into nervous system function. Deriving statistical models of cortical connectivity offers far greater ability to investigate underlying network dynamics. Improved functional assessment opens new possibilities for diagnosis, prognostication, and outcome prediction in nervous system diseases. https://www.jove.com/v/60249 531 2019-11-01T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65910.jpg DeepOmicsAE: Representing Signaling Modules in Alzheimer's Disease with Deep Learning Analysis of Proteomics, Metabolomics, and Clinical Data DeepOmicsAE is a workflow centered on the application of a deep learning method (i.e., an autoencoder) to reduce the dimensionality of multi-omics data, providing a foundation for predictive models and signaling modules representing multiple layers of omics data. https://www.jove.com/v/65910 587 2023-12-15T22:00:00+00:00 JoVE no https://visualize.jove.com/17159150-adaptive-reconfiguration-of-fractal-small-world-human-brain-functional-networks monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17745.jpg Neuroplasticity Neuroplasticity reflects the brain's remarkable capacity to adapt and evolve, responding dynamically to learning, experiences, or injury by reorganizing its neural circuitry. This reorganization involves creating new neural connections and refining old ones through a series of biological processes that contribute to the brain's lifelong development and adaptability. • The brain's ability to change begins with the growth of dendrites and axons, which effectively increases the structural... https://www.jove.com/v/17745 61 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59083.jpg Dynamic Inter-subject Functional Connectivity Reveals Moment-to-Moment Brain Network Configurations Driven by Continuous or Communication Paradigms The goal of the described approach is to determine at what moments of the paradigm (temporal perspective), and between which regions (spatial perspective), significant reconfigurations in functional connectivity occur on functional magnetic resonance imaging recordings during which a time-locked stimulus is played. https://www.jove.com/v/59083 516 2019-03-21T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65150.jpg Modeling the Functional Network for Spatial Navigation in the Human Brain This paper presents an integrative approach to investigating the functional network for spatial navigation in the human brain. This approach incorporates a large-scale neuroimaging meta-analytic database, resting-state functional magnetic resonance imaging, and network modeling and graph-theoretical techniques. https://www.jove.com/v/65150 355 2023-10-13T20:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68588.jpg Soft Pneumatic Robot Modulates Graph Theory Metrics of Brain Network for Hand Rehabilitation After Stroke This study explores the effects of a configurable soft pneumatic robot on enhancing whole-brain network topology post-stroke. Graph theory analysis indicates significant improvements in clustering coefficient, path length, and global efficiency. Findings highlight the potential of programmable robotic protocols to modulate neuroplasticity and optimize functional recovery in stroke rehabilitation. https://www.jove.com/v/68588 330 2025-10-10T21:40:00+00:00 JoVE no https://visualize.jove.com/17163510-multi-gene-engineering-simultaneous-expression-and-knockdown-of-six-genes-off-a-single-platform monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10813.jpg In-vitro Mutagenesis To learn more about the function of a gene, researchers can observe what happens when the gene is inactivated or “knocked out,” by creating genetically engineered knockout animals. Knockout mice have been particularly useful as models for human diseases such as cancer, Parkinson’s disease, and diabetes. The Process Genes can be randomly knocked out, or specific genes can be targeted. To knock out a particular gene, an engineered piece of DNA called a targeting vector is used to replace the... https://www.jove.com/v/10813 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12033.jpg Experimental RNAi RNA interference (RNAi) is a cellular mechanism that inhibits gene expression by suppressing its transcription or activating the RNA degradation process. The mechanism was discovered by Andrew Fire and Craig Mello in 1998 in plants. Today, it is observed in almost all eukaryotes, including protozoa, flies, nematodes, insects, parasites, and mammals. This precise cellular mechanism of gene silencing has been developed into a technique that provides an efficient way to identify and determine the... https://www.jove.com/v/12033 135 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50159.jpg The MultiBac Protein Complex Production Platform at the EMBL Protein complexes catalyze key cellular functions. Detailed functional and structural characterization of many essential complexes requires recombinant production. MultiBac is a baculovirus/insect cell system particularly tailored for expressing eukaryotic proteins and their complexes. MultiBac was implemented as an open-access platform, and standard operating procedures developed to maximize its utility. https://www.jove.com/v/50159 831 2013-07-11T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55187.jpg Inducible T7 RNA Polymerase-mediated Multigene Expression System, pMGX This study describes methods for the T7-mediated co-expression of multiple genes from a single plasmid in Escherichia coli using the pMGX plasmid system. https://www.jove.com/v/55187 609 2017-06-27T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55916.jpg A Protocol for Multiple Gene Knockout in Mouse Small Intestinal Organoids Using a CRISPR-concatemer This protocol describes the steps for cloning multiple single guide RNAs into one guide RNA concatemer vector, which is of particular use in creating multi-gene knockouts using CRISPR/Cas9 technology. The generation of double knockouts in intestinal organoids is shown as a possible application of this method. https://www.jove.com/v/55916 713 2017-07-12T22:00:00+00:00 JoVE no https://visualize.jove.com/17172750-use-of-microarray-analysis-to-dissect-the-plant-defense-response monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1925.jpg Investigating Tissue- and Organ-specific Phytochrome Responses using FACS-assisted Cell-type Specific Expression Profiling in Arabidopsis thaliana The molecular basis of spatial-specific phytochrome responses is being investigated using transgenic plants that exhibit tissue- and organ-specific phytochrome deficiencies. The isolation of specific cells exhibiting induced phytochrome chromophore depletion by Fluorescence-Activated Cell Sorting followed by microarray analyses is being utilized to identify genes involved in spatial-specific phytochrome responses. https://www.jove.com/v/1925 610 2010-05-29T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11121.jpg Defenses Against Pathogens and Herbivores Plants present a rich source of nutrients for many organisms, making it a target for herbivores and infectious agents. Plants, though lacking a proper immune system, have developed an array of constitutive and inducible defenses to fend off these attacks. Mechanical defenses form the first line of defense in plants. The thick barrier formed by the bark protects plants from herbivores. Hard shells, modified branches like thorns, and modified leaves like spines can also discourage herbivores... https://www.jove.com/v/11121 146 2025-10-23T18:48:48+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12014.jpg DNA Microarrays Microarrays are high-throughput and relatively inexpensive assays that can be automated to analyze large quantities of data at a time. They are used in genome-wide studies to compare gene or protein expression under two varied conditions, such as healthy and diseased states. Microarrays consist of glass or silica slides on which probe molecules are covalently attached through surface functionalization. Most commonly, the slides are prepared through the chemisorption of silanes to silica... https://www.jove.com/v/12014 154 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53364.jpg Bacterial Leaf Infiltration Assay for Fine Characterization of Plant Defense Responses using the Arabidopsis thaliana-Pseudomonas syringae Pathosystem Quantification of pathogen growth is a powerful tool to characterize various Arabidopsis thaliana (hereafter: Arabidopsis) immune responses. The method described here presents an optimized syringe infiltration assay to quantify the Pseudomonas syringae pv. maculicola ES4326 growth in adult Arabidopsis leaves. https://www.jove.com/v/53364 710 2015-10-01T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/69026.jpg Evaluating Leaf Responses to Microbial Secondary Metabolites Using A High-Throughput Format This protocol describes a high-throughput approach for evaluating plant ion leakage, peroxidase activity, and callose production in the same sample. https://www.jove.com/v/69026 351 2025-12-05T21:00:00+00:00 JoVE no https://visualize.jove.com/17194933-aminoacyl-trna-synthesis-by-pre-translational-amino-acid-modification monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11591.jpg Transfer RNA Synthesis One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases. Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with... https://www.jove.com/v/11591 156 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11595.jpg tRNA Activation Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the... https://www.jove.com/v/11595 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11597.jpg Improving Translational Accuracy Base complementarity between the three base pairs of mRNA codon and the tRNA anticodon is not a failsafe mechanism. Inaccuracies can range from a single mismatch to no correct base pairing at all. The free energy difference between the correct and nearly correct base pairs can be as small as 3 kcal/ mol. With complementarity being the only proofreading step, the estimated error frequency would be one wrong amino acid in every 100 amino acids incorporated. However, error frequencies observed in... https://www.jove.com/v/11597 127 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12564.jpg Pre-mRNA Processing: Modification of pre-mRNA Ends In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA. Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps the cell... https://www.jove.com/v/12564 95 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11591.jpg Transfer RNA Synthesis One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases. Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with... https://www.jove.com/v/12569 156 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11595.jpg tRNA Activation Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the... https://www.jove.com/v/13132 146 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54273.jpg Residue-specific Incorporation of Noncanonical Amino Acids into Model Proteins Using an Escherichia coli Cell-free Transcription-translation System An easy-to-use, cell-free expression protocol for the residue-specific incorporation of noncanonical amino acid analogs into proteins, including downstream analysis, is presented for medical, pharmaceutic, structural and functional studies. https://www.jove.com/v/54273 707 2016-08-01T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63320.jpg Residue-Specific Exchange of Proline by Proline Analogs in Fluorescent Proteins: How "Molecular Surgery" of the Backbone Affects Folding and Stability To overcome the limitations of classical site-directed mutagenesis, proline analogs with specific modifications were incorporated into several fluorescent proteins. We show how the replacement of hydrogen by fluorine or of the single by double bonds in proline residues ("molecular surgery") affects fundamental protein properties, including their folding and interaction with light. https://www.jove.com/v/63320 631 2022-02-03T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66605.jpg Synthesizing Amino Acids Modified with Reactive Carbonyls in Silico to Assess Structural Effects Using Molecular Dynamics Simulations Here, we describe a protocol for the optimization and parameterization of amino acid residues modified with reactive carbonyl species, adaptable to protein systems. The protocol steps include structure design and optimization, charge assignments, parameter construction, and preparation of protein systems. https://www.jove.com/v/66605 357 2024-04-26T21:30:00+00:00 JoVE no https://visualize.jove.com/17196751-relationships-between-locomotor-activation-and-alterations-in-brain-temperature-during-selective-blockade-and-stimulation-of-dopamine-transmission monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15010.jpg Drugs Affecting Neurotransmitter Synthesis Drugs affecting neurotransmitter synthesis can impact the adrenergic neuron and the synthesis of neurotransmitters. For example, α-methyltyrosine and carbidopa target specific enzymes involved in catecholamine synthesis. α-methyltyrosine inhibits the enzyme tyrosine hydroxylase, which converts tyrosine into dopamine. By blocking this enzyme, α-methyltyrosine reduces dopamine production and other catecholamines. Carbidopa, on the other hand, inhibits the enzyme dopa decarboxylase, which converts... https://www.jove.com/v/15010 89 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53951.jpg A Novel Approach to Assess Motor Outcome of Deep Brain Stimulation Effects in the Hemiparkinsonian Rat: Staircase and Cylinder Test Deep brain stimulation (DBS) is an effective treatment option for Parkinson's disease. We established a study design to screen novel stimulation paradigms in rats. The protocol describes the use of the staircase test and cylinder test for motor outcome assessment in DBS treated hemiparkinsonian rats. https://www.jove.com/v/53951 434 2016-05-31T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60706.jpg Measuring and Manipulating Functionally Specific Neural Pathways in the Human Motor System with Transcranial Magnetic Stimulation This article describes new approaches to measure and strengthen functionally specific neural pathways with transcranial magnetic stimulation. These advanced noninvasive brain stimulation methodologies can provide new opportunities for the understanding of brain-behavior relations and development of new therapies to treat brain disorders. https://www.jove.com/v/60706 592 2020-02-23T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63478.jpg In vivo Positron Emission Tomography to Reveal Activity Patterns Induced by Deep Brain Stimulation in Rats We describe a preclinical experimental method to evaluate metabolic neuromodulation induced by acute deep brain stimulation with in vivo FDG-PET. This manuscript includes all experimental steps, from stereotaxic surgery to the application of the stimulation treatment and the acquisition, processing, and analysis of PET images. https://www.jove.com/v/63478 576 2022-03-23T19:45:00+00:00 JoVE no https://visualize.jove.com/17225799-implementation-of-the-near-field-signal-redundancy-phase-aberration-correction-algorithm-on-two-dimensional-arrays monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/18014/18014_article_thumb_18014.jpg Distance Corrections To achieve precise distance measurements, especially in surveying and construction, certain corrections must be applied to account for potential sources of error like the standardization errors, temperature variations, and slope adjustments.Standardization error emerges when measurement equipment undergoes changes, such as wear, repairs, or weather impacts. To address this, surveyors compare the equipment’s readings to a standard. This process identifies any deviation that might lead to... https://www.jove.com/v/18014 75 2025-08-29T19:09:52+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18111/18111_article_thumb_18111.jpg Area Computation by the Alternative Coordinate Method The alternative coordinate method, also known as the Shoelace Formula, is a technique for determining the area of a traverse using Cartesian coordinates. This method relies on the sequential arrangement of x and y coordinates for each point of the shape, ensuring accuracy and ease of application.In this approach, each corner's x and y coordinates are listed as fractions, with the x-coordinate as the numerator and the y-coordinate as the denominator. These coordinates are arranged sequentially... https://www.jove.com/v/18111 84 2025-03-26T22:21:51+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40610/40610_article_thumb_40610.jpg Polar Coordinates: Problem Solving Directional radiation patterns are central to antenna analysis, as they illustrate how signal strength varies with direction. These patterns are often modeled using polar plots, where the radial distance from the origin represents signal intensity at a given angle. A commonly used idealized form is the four-lobed rose curve, which captures the concept of directional beams in a simplified mathematical form.The four-lobed rose curve, described by r = cos⁡(2θ), features four symmetric lobes, each... https://www.jove.com/v/40610 87 2026-06-08T16:38:17+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51148.jpg Time Multiplexing Super Resolving Technique for Imaging from a Moving Platform A method for overcoming the optical diffraction limit is presented. The method includes a two-step process: optical phase retrieval using iterative Gerchberg-Saxton algorithm, and imaging system shifting followed by repetition of the first step. A synthetically increased lens aperture is generated along the direction of movement, yielding higher imaging resolution. https://www.jove.com/v/51148 385 2014-02-13T06:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53025.jpg Measurement of X-ray Beam Coherence along Multiple Directions Using 2-D Checkerboard Phase Grating The measurement protocol and data analysis procedure are given for obtaining transverse coherence of a synchrotron radiation X-ray source along four directions simultaneously using a single 2-D checkerboard phase grating. This simple technique can be applied for complete transverse coherence characterization of X-ray sources and X-ray optics. https://www.jove.com/v/53025 639 2016-10-11T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59158.jpg Shaping the Amplitude and Phase of Laser Beams by Using a Phase-only Spatial Light Modulator We show how to encode the complex field of laser beams by using a single phase element. A common-path interferometer is employed to mix the phase information displayed into a phase-only spatial light modulator to finally retrieve the desired complex field pattern at the output of an optical imaging system. https://www.jove.com/v/59158 519 2019-01-28T23:00:00+00:00 JoVE no https://visualize.jove.com/17238246-integration-of-structure-activity-relationship-and-artificial-intelligence-systems-to-improve-in-silico-prediction-of-ames-test-mutagenicity monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3259.jpg A Protocol for Computer-Based Protein Structure and Function Prediction Guidelines for computer based structural and functional characterization of protein using the I-TASSER pipeline is described. Starting from query protein sequence, 3D models are generated using multiple threading alignments and iterative structural assembly simulations. Functional inferences are thereafter drawn based on matches to proteins with known structure and functions. https://www.jove.com/v/3259 1001 2011-11-03T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10813.jpg In-vitro Mutagenesis To learn more about the function of a gene, researchers can observe what happens when the gene is inactivated or “knocked out,” by creating genetically engineered knockout animals. Knockout mice have been particularly useful as models for human diseases such as cancer, Parkinson’s disease, and diabetes. The Process Genes can be randomly knocked out, or specific genes can be targeted. To knock out a particular gene, an engineered piece of DNA called a targeting vector is used to replace the... https://www.jove.com/v/10813 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10813.jpg In vitro Mutagenesis To learn more about the function of a gene, researchers can observe what happens when the gene is inactivated or “knocked out,” by creating genetically engineered knockout animals. Knockout mice have been particularly useful as models for human diseases such as cancer, Parkinson’s disease, and diabetes. The Process Genes can be randomly knocked out, or specific genes can be targeted. To knock out a particular gene, an engineered piece of DNA called a targeting vector is used to replace the... https://www.jove.com/v/12024 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14392.jpg Mutagenicity and Carcinogenicity Mutagenicity and carcinogenicity refer to the ability of drugs to cause genetic defects and induce cancer, respectively. The International Agency for Research on Cancer (IARC) classifies agents into four groups based on their carcinogenic potential. Group 1 agents are known human carcinogens; group 2A agents are probably carcinogenic to humans; group 3 agents lack data to support their role in carcinogenesis; and group 4 includes agents for which data support that they are not likely to be... https://www.jove.com/v/14392 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16472.jpg Structure-Activity Relationships and Drug Design Drug design is a dynamic field that involves discovering and developing new medications based on specific biological targets. This process heavily relies on structure-activity relationships (SAR) and quantitative structure-activity relationships (QSAR) to guide the design and optimization of efficient drugs. SAR studies the intricate relationship between a drug's chemical structure and biological activity. It focuses on understanding how modifications to a drug's structure can influence its... https://www.jove.com/v/16472 88 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63970.jpg Demonstration of the Sequence Alignment to Predict Across Species Susceptibility Tool for Rapid Assessment of Protein Conservation Here, we present a protocol to utilize the latest version of the US Environmental Protection Agency Sequence Alignment to Predict Across Species Susceptibility (SeqAPASS) tool. This protocol demonstrates the application of the online tool to rapidly analyze protein conservation and provide customizable and easily interpretable predictions of chemical susceptibility across species. https://www.jove.com/v/63970 962 2023-02-10T20:05:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64820.jpg Probing RNA Structure with Dimethyl Sulfate Mutational Profiling with Sequencing In Vitro and in Cells The protocol provides instruction for modifying RNA with dimethyl sulfate for mutational profiling experiments. It includes in vitro and in vivo probing with two alternative library preparation methods. https://www.jove.com/v/64820 634 2022-12-09T22:50:00+00:00 JoVE no https://visualize.jove.com/17259219-small-angle-x-ray-characterization-of-the-nucleoprotein-complexes-resulting-from-dna-induced-oligomerization-of-hiv-1-integrase monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/19587/19587_article_thumb_19587.jpg Size and Structure of Viral Genomes Viral genomes exhibit remarkable diversity in size, structure, and composition, influencing their replication strategies and interactions with host cells. These genomes consist of either DNA or RNA and may be linear or circular. Additionally, they can be single-stranded or double-stranded, with each configuration affecting how the virus propagates within a host. RNA viruses, for instance, generally have smaller genomes than DNA viruses, a factor that contributes to their high mutation rates and... https://www.jove.com/v/19587 86 2025-06-12T16:27:55+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/41743/41743_article_thumb_41743.jpg Inhibitors of Virion Maturation and Assembly As part of their replication cycle, certain viruses synthesize long precursor proteins called polyproteins within infected host cells. In human immunodeficiency virus (HIV), two major polyproteins are produced: Gag and Gag-Pol. The Gag polyprotein supplies the structural components of the virus, while Gag-Pol includes essential viral enzymes such as reverse transcriptase, integrase, and protease. After synthesis, these polyproteins move to the host cell membrane, where they assemble into an... https://www.jove.com/v/41743 79 2026-05-20T21:38:19+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52474.jpg Nucleocapsid Annealing-Mediated Electrophoresis (NAME) Assay Allows the Rapid Identification of HIV-1 Nucleocapsid Inhibitors This protocol describes NAME, an assay that allows the rapid identification of molecules able to inhibit in vitro the chaperone activities of HIV-1 nucleocapsid protein. https://www.jove.com/v/52474 513 2015-01-19T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54581.jpg Measurement of In Vitro Integration Activity of HIV-1 Preintegration Complexes This report describes an in vitro assay for measuring the human immunodeficiency virus type 1 (HIV-1) preintegration complex (PIC)-associated integration activity in the cytoplasmic extracts of acutely infected cells. The integration of PIC-associated HIV-1 DNA into heterologous target DNA is quantified by using a nested real-time polymerase chain reaction strategy. https://www.jove.com/v/54581 634 2017-02-22T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57453.jpg Assembly and Purification of Prototype Foamy Virus Intasomes Recombinant retroviral integrase and DNA oligomers mimicking viral DNA ends can form an enzymatically active complex known as an intasome. Intasomes may be used for biochemical, structural, and kinetic studies. This protocol details how to assemble and purify prototype foamy virus intasomes. https://www.jove.com/v/57453 620 2018-03-19T22:00:00+00:00 JoVE no https://visualize.jove.com/17267632-evaluation-of-the-performance-of-the-automated-nuclisens-easymag-and-easyq-systems-versus-the-roche-ampliprep-amplicor-combination-for-high-throughput-monitoring-of-human-immunodeficiency-virus-load monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2312.jpg Comprehensive & Cost Effective Laboratory Monitoring of HIV/AIDS: an African Role Model Anti-retroviral therapy to treat HIV/AIDS is monitored in South Africa on a large scale. Flow cytometry is combined for haematology (CD45), immunology (CD4) and viral-load linked CD38 assay. Recorded at NHLS-SA laboratories, Johannesburg, these modern methods are cost-efficient with heightened local internal quality control, serving as role-models for resource-limited diagnostics. https://www.jove.com/v/2312 1436 2010-11-01T00:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/2960.jpg Amplifying and Quantifying HIV-1 RNA in HIV Infected Individuals with Viral Loads Below the Limit of Detection by Standard Clinical Assays Quantifying levels of HIV-1 RNA in plasma and sequencing single HIV-1 genomes from individuals with viral loads below the limit of detection (50-75 copies/ml) is difficult. Here we describe how to extract and quantify plasma viral RNA using a real time PCR assay that reliably measures HIV-1 RNA down to 0.3 copies/ml and how to amplify viral genomes by single genome sequencing, from samples with very low viral loads. https://www.jove.com/v/2960 838 2011-09-26T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52620.jpg Development of a Quantitative Recombinase Polymerase Amplification Assay with an Internal Positive Control Provided is a protocol for developing a real-time recombinase polymerase amplification assay to quantify initial concentration of DNA samples using either a thermal cycler or a microscope and stage heater. Also described is the development of an internal positive control. Scripts are provided for processing raw real-time fluorescence data. https://www.jove.com/v/52620 517 2015-03-30T22:00:00+00:00 JoVE no https://visualize.jove.com/17271567-nonlinear-methods-for-biopattern-analysis-role-and-challenges monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/55513.jpg A Versatile Method of Patterning Proteins and Cells This report describes a simple, easy to perform technique, using low pressure vacuum, to fill microfluidic channels with cells and substrates for biological research. https://www.jove.com/v/55513 597 2017-02-26T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59634.jpg Mapping the Emergent Spatial Organization of Mammalian Cells using Micropatterns and Quantitative Imaging The method presented here uses micropatterning together with quantitative imaging to reveal spatial organization within mammalian cultures. The technique is easy to establish in a standard cell biology laboratory and offers a tractable system to study patterning in vitro. https://www.jove.com/v/59634 596 2019-04-30T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60092.jpg Light-Induced Molecular Adsorption of Proteins Using the PRIMO System for Micro-Patterning to Study Cell Responses to Extracellular Matrix Proteins Our overall aim is to understand how cells sense extracellular cues that lead to directed axonal growth. Here, we describe the methodology of Light-Induced Molecular Adsorption of Proteins, used to produce defined micro-patterns of extracellular matrix components in order to study specific events that govern axon outgrowth and pathfinding. https://www.jove.com/v/60092 589 2019-10-11T20:00:00+00:00 JoVE no https://visualize.jove.com/17281961-adaptive-threshold-for-qrs-complex-detection-based-on-wavelet-transform monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14521.jpg Difference from Background: Limit of Detection The limit of detection (LOD) is the smallest amount of analyte that can be distinguished from the background noise. The LOD value corresponds to the concentration at which the analyte signal is three times larger than the standard deviation of the blank signal. Below this value, the analyte signal cannot be differentiated from the background noise. It is calculated by dividing the calibration slope by 3 times the standard deviation of the blank signals. The LOD indicates the presence or absence... https://www.jove.com/v/14521 65 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15273.jpg Electrocardiogram An electrocardiogram (ECG or EKG) is a critical diagnostic tool that records the electrical signals produced by the heart during each heartbeat. This recording is achieved through electrodes placed strategically on the arms, legs, and chest. The electrocardiograph amplifies these signals and produces 12 distinct tracings, offering a comprehensive understanding of the heart's electrical activity. Three major waveforms are present in a typical ECG recording: the P wave, the QRS complex, and the T... https://www.jove.com/v/15273 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15275.jpg Correlation between ECG and Cardiac Cycle The electrical signals recorded on an electrocardiogram (ECG) occur before the mechanical processes of contraction and relaxation during the cardiac cycle. A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before... https://www.jove.com/v/15275 85 2025-05-15T15:16:28+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17877.jpg Electrocardiogram Fundamentals Introduction An electrocardiogram (ECG) is a diagnostic tool for identifying cardiac conditions such as arrhythmias, conduction abnormalities, and myocardial ischemia. Definition An electrocardiogram (ECG) visualizes the heart's electrical activity by tracing the electrical movement associated with each heartbeat on a graph or monitor. As the heart beats, an electrical wave passes through it, correlating with the cardiac cycle events. Parts of an ECG An ECG utilizes electrodes on the skin to... https://www.jove.com/v/17877 88 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59200.jpg Data Acquisition and Analysis In Brainstem Evoked Response Audiometry In Mice Brainstem evoked response audiometry is an important tool in clinical neurophysiology. Nowadays, brainstem evoked response audiometry is also applied in the basic science and preclinical studies involving both pharmacological and genetic animal models. Here we provide a detailed description of how auditory brainstem responses can be successfully recorded and analyzed in mice. https://www.jove.com/v/59200 531 2019-05-10T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60011.jpg In Vivo Surface Electrocardiography for Adult Zebrafish Here, we present a reliable, minimally invasive, and cost-effective method to record and interpret electrocardiograms in live anesthetized adult zebrafish. https://www.jove.com/v/60011 553 2019-08-01T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62386.jpg Analyzing Long-Term Electrocardiography Recordings to Detect Arrhythmias in Mice Here we present a step-by-step protocol for a semiautomated approach to analyze murine long-term electrocardiography (ECG) data for basic ECG parameters and common arrhythmias. Data are obtained by implantable telemetry transmitters in living and awake mice and analyzed using Ponemah and its analysis modules. https://www.jove.com/v/62386 367 2021-05-23T18:00:00+00:00 JoVE no https://visualize.jove.com/17282180-classification-of-impulse-oscillometric-patterns-of-lung-function-in-asthmatic-children-using-artificial-neural-networks monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16360.jpg Asthma-I: Introduction Asthma is a chronic respiratory ailment that requires careful management due to its varying symptoms and influencing factors. It is characterized by airway inflammation, bronchial hyperresponsiveness, and reversible airflow obstruction, leading to symptoms like wheezing, shortness of breath, chest tightness, and coughing. The symptom frequency and intensity may vary considerably over time. It is also linked to immune system responses to allergens and irritants, highlighting the complex... https://www.jove.com/v/16360 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16361.jpg Asthma-II: Pathophysiology and Classification Asthma is a prevalent chronic respiratory condition marked by inflammation and hyperresponsiveness of the airways. Its pathophysiology involves complex interactions among inflammatory pathways, immune responses, and neural mechanisms. Additionally, environmental and genetic factors play crucial roles in determining an individual's susceptibility to asthma and the severity of their condition. Critical processes in asthma pathophysiology include: Initiation of Airway Inflammation: Trigger... https://www.jove.com/v/16361 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16363.jpg Asthma-IV: Diagnostic and Management The diagnosis and management of asthma are comprehensive, encompassing clinical assessments, lung function tests, and pharmacological interventions. Here's an overview: Clinical Assessment for Asthma: This is the first step in diagnosing and managing asthma. It includes: Detailed Medical History: This includes asking about symptoms such as wheezing, coughing, chest tightness, and breathlessness. Information about triggers like exercise, allergens, or cold air is crucial. Physical... https://www.jove.com/v/16363 90 JoVE no https://cloudfront.jove.com/files/ftp_upload/40975/40975_article_thumb_40975.jpg Asthma I: Introduction Asthma is a chronic inflammatory disorder of the airways characterized by variable airflow obstruction and heightened bronchial responsiveness to a wide range of triggers. The underlying inflammation leads to airway swelling, mucus hypersecretion, and smooth muscle constriction, all of which narrow the airway lumen and impede airflow. Clinically, asthma presents with recurrent episodes of wheezing, shortness of breath, chest tightness, and coughing, symptoms that typically vary in intensity and... https://www.jove.com/v/40975 88 2026-04-21T19:47:27+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63243.jpg Conducting Respiratory Oscillometry in an Outpatient Setting We demonstrate a standard operating protocol to conduct respiratory oscillometry, highlighting key quality control and assurance procedures. https://www.jove.com/v/63243 889 2022-04-08T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67742.jpg Asthma Detection Research Based on Voice Signal Processing and Machine Learning This study employed voice signal analysis and machine learning methods, utilizing MATLAB to extract distinctive voice features for non-invasive early detection of asthma. The Support Vector Machine (SVM) and Random Forest (RF) algorithms demonstrated comparable performance in terms of overall classification accuracy, although SVM may achieve a better balance between sensitivity and specificity. https://www.jove.com/v/67742 244 2025-07-22T19:40:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68222.jpg Machine Learning-Based Cough Tone Classification: Diagnostic Exploration of Chronic Obstructive Pulmonary Disease and Respiratory Tract Infections This study effectively accomplished the automated classification of two distinct categories by acquiring cough sound data from patients diagnosed with chronic obstructive pulmonary disease (COPD) and respiratory tract infections (RTI), utilizing an integration of speech signal processing techniques and machine learning algorithms. https://www.jove.com/v/68222 382 2025-09-19T20:45:00+00:00 JoVE no https://visualize.jove.com/17285305-evaluation-of-amplified-crna-targets-for-oligonucleotide-microarrays monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1622.jpg A Rapid High-throughput Method for Mapping Ribonucleoproteins (RNPs) on Human pre-mRNA Due to the transient nature of pre-mRNA, it can be difficult to isolate and study in vivo. Here, we present a novel in vitro approach to investigate RNA-protein interactions using a synthetic oligo pool that tiles across selected regions of pre-mRNA. https://www.jove.com/v/1622 780 2009-12-02T23:46:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/2585.jpg Microarray Analysis for Saccharomyces cerevisiae In this protocol, gene expression in yeast (Saccharomyces cerevisiae) is changed after exposure to oxidative stress induced by the addition of hydrogen peroxide (H2O2), an oxidizing agent. https://www.jove.com/v/2585 797 2011-04-07T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12014.jpg DNA Microarrays Microarrays are high-throughput and relatively inexpensive assays that can be automated to analyze large quantities of data at a time. They are used in genome-wide studies to compare gene or protein expression under two varied conditions, such as healthy and diseased states. Microarrays consist of glass or silica slides on which probe molecules are covalently attached through surface functionalization. Most commonly, the slides are prepared through the chemisorption of silanes to silica... https://www.jove.com/v/12014 154 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12018.jpg Real Time RT-PCR Real-time reverse transcription-polymerase chain reaction, or Real-time RT-PCR, is an analytical tool used to determine the expression level of target genes. The method involves converting mRNA to complementary DNA with the help of an enzyme known as reverse transcriptase, followed by the PCR amplification of the cDNA. These two processes can be performed simultaneously in a single tube or separately as a two-step reaction. The real-time quantification of the number of amplified products is... https://www.jove.com/v/12018 177 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51285.jpg Profiling of Estrogen-regulated MicroRNAs in Breast Cancer Cells Molecular signaling through both estrogen and microRNAs are critical in breast cancer development and growth. Estrogen activates the estrogen receptors, which are transcription factors. Many transcription factors can regulate the expression of microRNAs, and estrogen-regulated microRNAs can be profiled using different large-scale techniques. https://www.jove.com/v/51285 984 2014-02-21T22:30:00+00:00 JoVE no https://visualize.jove.com/17315223-dynamics-of-spontaneous-transitions-between-global-brain-states monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/14894/14894_article_thumb_14894.jpg Propagation of Action Potentials The propagation of an action potential refers to the process by which a nerve impulse, or "action potential," travels along a neuron. Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to... https://www.jove.com/v/14894 83 2025-08-11T22:39:58+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/15761/15761_article_thumb_15761.jpg Entropy Changes Accompanying Specific Processes Entropy, a measure of disorder in a system, changes during phase transitions like freezing or boiling. At the transition temperature Ttrs, where two phases are in equilibrium, the phase transition is a reversible process. The entropy change can be calculated from a substance's enthalpy of transition using the equation ΔStrs = ΔtrsH /Ttrs.When a perfect gas expands isothermally from one volume to another, entropy increases logarithmically with volume. Conversely, isothermal compression results... https://www.jove.com/v/15761 81 2026-02-26T21:07:28+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/15832/15832_article_thumb_15832.png Transition State Theory Transition-state theory, also known as activated-complex theory, provides a molecular-level explanation of reaction rates in both gas-phase and solution-phase reactions. It extends earlier kinetic models by considering the formation of a short-lived, high-energy configuration during a reaction.The progress of a chemical reaction can be represented using a reaction profile, which plots potential energy against the reaction coordinate. As two reactant molecules approach one another, their... https://www.jove.com/v/15832 85 2026-04-29T21:06:54+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17742.jpg Neurons as Communicators of the Brain Neurons, the fundamental units of the brain and nervous system, function as the primary transmitters of information throughout the body. Their ability to communicate through electrical and chemical signals is vital for every bodily function, from regulating the heartbeat to processing complex thoughts. Each neuron has three main components: the cell body (soma), dendrites, and an axon, each specialized to facilitate swift and efficient neural communication. Cell Body The cell body, also known... https://www.jove.com/v/17742 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17743.jpg Neuronal Communication Neurons, the fundamental units of the brain and nervous system, communicate through complex electrochemical signals that underpin all cognitive and bodily functions. This communication is primarily facilitated by a process involving the generation and propagation of an action potential along the axon of the neuron. When the internal electrical charge of a neuron surpasses a certain threshold, an action potential is triggered. This rapid change in voltage travels swiftly along the axon to the... https://www.jove.com/v/17743 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17785.jpg High-Level and Low-Level Awareness Controlled processes in human consciousness represent high-alert mental states where individuals deliberately focus their attention on achieving specific goals. Controlled processes can be seen in situations like mastering new technology, where a person might become so absorbed that they ignore surrounding distractions. Such processes involve selective attention, requiring one to concentrate on particular elements of experience while disregarding others. These are governed by executive... https://www.jove.com/v/17785 79 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52877.jpg Generation of Local CA1 γ Oscillations by Tetanic Stimulation Oscillations are fundamental network properties and are modulated by disease and drugs. Studying brain-slice oscillations allows characterization of isolated networks under controlled conditions. Protocols are provided for the preparation of acute brain slices for evoking CA1 γ oscillations. https://www.jove.com/v/52877 482 2015-08-14T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53576.jpg Induction of an Isoelectric Brain State to Investigate the Impact of Endogenous Synaptic Activity on Neuronal Excitability In Vivo This procedure performs long-lasting in vivo intracellular recordings from single neurons during physiologically relevant cerebral states and after complete abolition of ongoing electrical activities, resulting in an isoelectric brain state. The physiological constants of the animal are carefully monitored during the transition to the artificial comatose condition. https://www.jove.com/v/53576 619 2016-03-31T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57952.jpg Generation and On-Demand Initiation of Acute Ictal Activity in Rodent and Human Tissue Acute seizure models are important for studying the mechanisms underlying epileptiform events. Furthermore, the ability to generate epileptiform events on-demand provides a highly efficient method to study the exact sequence of events underlying their initiation. Here, we describe the acute 4-aminopyridine cortical seizure models established in mouse and human tissue. https://www.jove.com/v/57952 405 2019-01-19T20:30:00+00:00 JoVE no https://visualize.jove.com/17336544-mass-analysis-in-islands-of-stability-with-linear-quadrupoles-with-added-octopole-fields monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1954.jpg Analyzing Large Protein Complexes by Structural Mass Spectrometry Mass spectrometry has proven to be a valuable tool for analyzing large protein complexes. This method enables insights into the composition, stoichiometry and overall architecture of multi-subunit assemblies. Here, we describe, step-by-step, how to perform a structural mass spectrometry analysis, and characterize macromolecular structures. https://www.jove.com/v/1954 935 2010-06-20T00:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11339.jpg Molecular Orbital Theory II Molecular Orbital Energy Diagrams The relative energy levels of atomic and molecular orbitals are typically shown in a molecular orbital diagram. For a diatomic molecule, the atomic orbitals of one atom are shown on the left, and those of the other atom are shown on the right. Each horizontal line represents one orbital that can hold two electrons. The molecular orbitals formed by the combination of the atomic orbitals are shown in the center. Dashed lines show which of the atomic orbitals... https://www.jove.com/v/11339 231 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12275.jpg ¹H NMR: Complex Splitting A proton M that is coupled to a proton X results in doublet signals for M. However, NMR-active nuclei can be simultaneously coupled to more than one nonequivalent nucleus. When M is coupled to a second proton A, such as in styrene oxide, each peak in the doublet is split into another doublet. Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied first. https://www.jove.com/v/12275 73 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13040.jpg Mass Spectrometry: Isotope Effect Most elements exist in nature as a mixture of isotopes. The isotopes differ in weight due to their respective number of neutrons. The molecular weight of a molecule is different depending on the specific isotope of its elements involved. As a result, the mass spectrum of the molecule exhibits peaks from the same fragment at multiple positions. The positions of these mass signals depend on the mass differences between isotopes. Furthermore, the intensity of these signals is dependent on the... https://www.jove.com/v/13040 73 2025-12-12T20:30:35+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14590.jpg Mass Analyzers: Overview The mass analyzer is a crucial component of the mass spectrometer. In the ionization chamber, the vaporized sample is bombarded with a high-energy electron beam to generate a radical cation and further fragment into neutral molecules, radicals, and cations. A series of negatively charged accelerator plates accelerate the cations into the mass analyzer. The mass analyzer separates ions according to their mass-to-charge (m/z) ratios and then directs them to the detector. The common types of mass... https://www.jove.com/v/14590 73 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14591.jpg Mass Analyzers: Common Types The quadrupole mass analyzer consists of four cylindrical metal rods arranged in a diamond carrying a DC voltage and a radio-frequency AC voltage. The motion of ions through the quadrupole depends on the field strength, causing only ions of a certain m/z to resonate successfully and strike the detector at a given field strength. Though the transmission rate for these analyzers is high, the exact elemental composition of the sample is not determined because of low resolution; however, they are... https://www.jove.com/v/14591 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14592.jpg Mass Spectrometry: Complex Analysis Mass spectrometry is an important technique for the identification of pure compounds. However, it has some limitations for the analysis of complex mixtures, often due to excessive fragmentation making the spectrum too complicated to decipher. Mass spectrometry can be combined with suitable separation methods in sequence, forming hyphenated methods, which are useful in the analysis of complex mixtures. GC–MS is a powerful hyphenated method commonly used in forensics and environmental... https://www.jove.com/v/14592 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51137.jpg Spatial Separation of Molecular Conformers and Clusters We present a technique that allows the spatial separation of different conformers or clusters present in a molecular beam. An electrostatic deflector is used to separate species by their mass-to-dipole moment ratio, leading to the production of gas-phase ensembles of a single conformer or cluster stoichiometry. https://www.jove.com/v/51137 637 2014-01-09T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63451.jpg Using a Cyclic Ion Mobility Spectrometer for Tandem Ion Mobility Experiments Ion mobility spectrometry (IMS) is an interesting complement to mass spectrometry for the characterization of biomolecules, notably because it is sensitive to isomerism. This protocol describes a tandem IMS (IMS/IMS) experiment, which allows the isolation of a molecule and the generation of the mobility profiles of its fragments. https://www.jove.com/v/63451 520 2022-01-20T23:00:00+00:00 JoVE no https://visualize.jove.com/17348773-an-augmented-extended-kalman-filter-algorithm-for-complex-valued-recurrent-neural-networks monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16077.jpg Sampling Continuous Time Signal In signal processing, a continuous-time signal can be sampled using an impulse-train sampling technique, followed by the zero-order hold method. Impulse-train sampling involves the use of a periodic impulse train, which consists of a series of delta functions spaced at regular intervals determined by the sampling period. When a continuous-time signal is multiplied by this impulse train, it generates impulses with amplitudes corresponding to the signal's values at the sampling points. In the... https://www.jove.com/v/16077 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16099.jpg Linear Approximation in Frequency Domain Linear systems are characterized by two main properties: superposition and homogeneity. Superposition allows the response to multiple inputs to be the sum of the responses to each individual input. Homogeneity ensures that scaling an input by a scalar results in the response being scaled by the same scalar. In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear. https://www.jove.com/v/16099 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16100.jpg State Space Representation The frequency-domain technique, commonly used in analyzing and designing feedback control systems, is effective for linear, time-invariant systems. However, it falls short when dealing with nonlinear, time-varying, and multiple-input multiple-output systems. The time-domain or state-space approach addresses these limitations by utilizing state variables to construct simultaneous, first-order differential equations, known as state equations, for an nth-order system. Consider an RLC circuit, a... https://www.jove.com/v/16100 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16102.jpg State Space to Transfer Function The conversion of state-space representation to a transfer function is a fundamental process in system analysis. It provides a method for transitioning from a time-domain description to a frequency-domain representation, which is crucial for simplifying the analysis and design of control systems. The transformation process begins with the state-space representation, characterized by the state equation and the output equation. These equations are typically represented as: Where x(t) is the... https://www.jove.com/v/16102 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16107.jpg Multi-input and Multi-variable systems Cruise control systems in cars are designed as multi-input systems to maintain a driver's desired speed while compensating for external disturbances such as changes in terrain. The block diagram for a cruise control system typically includes two main inputs: the desired speed set by the driver and any external disturbances, such as the incline of the road. By adjusting the engine throttle, the system maintains the vehicle's speed as close to the desired value as possible. In the absence of... https://www.jove.com/v/16107 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16576.jpg One-Compartment Open Model: Wagner-Nelson and Loo Riegelman Method for k a Estimation This lesson introduces two critical methods in pharmacokinetics, the Wagner-Nelson and Loo-Riegelman methods, used for estimating the absorption rate constant (ka) for drugs administered via non-intravenous routes. The Wagner-Nelson method relates ka to the plasma concentration derived from the slope of a semilog percent unabsorbed time plot. However, it is limited to drugs with one-compartment kinetics and can be impacted by factors like gastrointestinal motility or enzymatic degradation. On... https://www.jove.com/v/16576 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59898.jpg A Method for Tracking the Time Evolution of Steady-State Evoked Potentials A protocol to assess the time evolution of the neural entrainment to external repetitive stimuli is presented. Steady-state recordings of the same experimental condition are acquired and averaged in the time-domain. The steady-state dynamics are analyzed by plotting the response amplitude as a function of time. https://www.jove.com/v/59898 723 2019-05-25T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63575.jpg Design and Application of a Fault Detection Method Based on Adaptive Filters and Rotational Speed Estimation for an Electro-Hydrostatic Actuator In this paper, an adaptive filter based on a normalized least mean square (NLMS) algorithm and a rotational speed estimation method are introduced to detect the electrical and hydraulic faults of the electro-hydrostatic actuator (EHA). The efficacy and feasibility of the aforementioned methods are verified through simulations and experiments. https://www.jove.com/v/63575 405 2022-10-28T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65554.jpg End-To-End Deep Neural Network for Salient Object Detection in Complex Environments The present protocol describes a novel end-to-end salient object detection algorithm. It leverages deep neural networks to enhance the precision of salient object detection within intricate environmental contexts. https://www.jove.com/v/65554 211 2023-12-15T21:10:00+00:00 JoVE no https://visualize.jove.com/17350856-effect-of-preoperative-angiotensin-converting-enzyme-inhibitor-or-angiotensin-receptor-blocker-use-on-the-frequency-of-atrial-fibrillation-after-cardiac-surgery-a-cohort-study-from-the-atrial-fibrillation-suppression-trials-ii-and-iii monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3671.jpg The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation The accompanying video describes a procedure for percutaneous placement of the WATCHMAN Left Atrial Appendage (LAA) Device. The WATCHMAN is a nitinol device designed to be permanently implanted at, or slightly distal to, the opening of the left atrial appendage (LAA) to trap blood clots before they exit the LAA, preventing thromboembolic stroke. https://www.jove.com/v/3671 1413 2012-02-28T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/3818.jpg Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation Catheter ablation is combined with placement of the WATCHMAN Left Atrial Appendage Closure Device to prevent ischemic stroke in a patient with non-valvular atrial fibrillation. https://www.jove.com/v/3818 2013-02-26T19:57:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15024.jpg Antihypertensive Drugs: Angiotensin II Receptor Blockers In the renin-angiotensin-aldosterone system, a hormone called angiotensin II plays a crucial role. It binds to the AT1 receptors in vascular smooth muscles coupled with Gq proteins. The activation of these receptors activates an enzyme called phospholipase C, which releases two molecules: inositol trisphosphate and diacylglycerol. These molecules cause a chain reaction that leads to the phosphorylation of myosin light chains and promotes interaction between actin and myosin, leading to smooth... https://www.jove.com/v/15024 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15025.jpg Antihypertensive Drugs: Direct Renin Inhibitors The renin-angiotensin-aldosterone system (RAAS) is an intricate physiological pathway involving numerous enzymes and hormones, including renin, angiotensin-converting enzyme (ACE), angiotensin I and II, and aldosterone. Imbalances within this system increase the production of angiotensin II and aldosterone. Increased angiotensin II levels promote vasoconstriction and blood pressure elevation. Concurrently, higher aldosterone levels stimulate sodium and water reabsorption in the kidneys,... https://www.jove.com/v/15025 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15030.jpg Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers Adrenergic stimulation generally impacts cardiac rate and rhythm. Specifically, stimulation of the β-adrenoceptors triggers an increase in intracellular calcium ion influx and pacemaker currents, which may cause arrhythmias. Catecholamines like adrenaline also demonstrate β2-adrenoceptor-mediated hypokalemia, impacting cardiac action potential and disrupting the normal cardiac rhythm. Class II antiarrhythmic drugs are β-adrenoceptor antagonists or β-blockers, which indirectly block calcium... https://www.jove.com/v/15030 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15037.jpg Heart Failure Drugs: Inhibitors of Renin-Angiotensin System The activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) contributes to cardiac remodeling, and inhibiting the RAAS is a pharmacological target in heart failure management. As a result, neurohumoral modulation is a crucial treatment principle for managing heart failure. This approach involves using medications like ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), β-blockers, mineralocorticoid receptor antagonists (MRAs), and neutral... https://www.jove.com/v/15037 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/17905/17905_article_thumb_17905.jpg Aortic Regurgitation III: Medical Management Aortic regurgitation (AR) is when the aortic valve does not close or seal properly, leading to backward blood circulation from the aorta into the left ventricle during diastole. Common causes of AR include rheumatic heart disease, congenital valve defects, and aortic root dilation. Managing AR requires a multifaceted approach to alleviate symptoms, preserve left ventricular function, and address the underlying cause of the regurgitation. Patients with symptomatic AR or significant left... https://www.jove.com/v/17905 85 2025-06-19T16:20:54+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17982/17982_article_thumb_17982.jpg Aneurysm IV: Nursing Management Vigilant monitoring for aneurysm rupture is essential for patients undergoing aortic surgery.Preoperative Nursing ManagementContinuously monitor the patient for manifestations of aneurysm rupture, such as pallor, weakness, tachycardia, hypotension, abdominal, back, groin, or periumbilical pain, changes in consciousness, and a pulsating abdominal mass. Regularly assess the patient's peripheral pulses.Instruct the patient to consume a clear liquid diet the day before surgery and administer... https://www.jove.com/v/17982 82 2025-06-19T16:19:35+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64417.jpg Reduced Procedure Time and Variability with Active Esophageal Cooling During Radiofrequency Ablation for Atrial Fibrillation This study utilized advanced informatics techniques to compare procedure duration in patients undergoing radiofrequency atrial ablation treated with active esophageal cooling to those treated with traditional luminal esophageal temperature monitoring. Contextual inquiry, workflow analysis, and data mapping were utilized. The findings demonstrated reduced procedure time and variability with active cooling. https://www.jove.com/v/64417 298 2022-08-25T22:00:00+00:00 JoVE no https://visualize.jove.com/17356004-lif-mediated-control-of-embryonic-stem-cell-self-renewal-emerges-due-to-an-autoregulatory-loop monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1550.jpg The use of SC1 (Pluripotin) to Support mESC Self-renewal in the Absence of LIF SC1 functions through dual inhibition of Ras- GAP and ERK1. We tested the function of SC1 in supporting mouse ES cell self-renewal in the absence of LIF and showed that SC1 is able to maintain self-renewal of mouse ES cell cultures. https://www.jove.com/v/1550 358 2009-11-19T01:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/3987.jpg Oct4GiP Reporter Assay to Study Genes that Regulate Mouse Embryonic Stem Cell Maintenance and Self-renewal We describe a fluorescence reporter assay to quickly identify and characterize genes that regulate mouse embryonic stem cell maintenance and self-renewal. https://www.jove.com/v/3987 481 2012-05-30T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12512.jpg Multipotency of Hematopoietic Stem Cells The hematopoietic stem cells or HSCs are multipotent, meaning they can differentiate and give rise to all blood and immune cells. HSCs are maintained in the quiescent stage until an external stimulus initiates their differentiation. The multipotent HSCs exist as two heterogeneous populations, long-term repopulating cells (LTRC) and short-term repopulating cells (STRC). The two HSC populations have different surface markers or receptors and are classified based on quiescence and long-term... https://www.jove.com/v/12512 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12516.jpg Regulation of Hematopoietic Stem Cells All blood and immune cells are produced from the multipotent hematopoietic stem cells (HSCs) by the process of hematopoiesis. However, they all have a limited life span. In addition, many are depleted in immune surveillance or combatting an injury or infection. This makes blood one of the most regenerative tissues. Hematopoiesis helps replenish these blood and immune cells, restoring the body's normal functioning. However, overproduction of blood and immune cells can make them cancerous or... https://www.jove.com/v/12516 61 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13463.jpg Stem Cell Niche The stem cell niche is the dynamic microenvironment where stem cells reside. Inside these niches, the cells may remain undifferentiated, undergo high self-renewal, or become lineage-specific progenitors. Stem cells coexist with other niche cells, such as stromal cells. They also interact closely with the ECM. Cell-cell and cell-matrix communication occur via adhesion molecules or soluble factors that signal the stem cells and determine their fate. Stromal cells also provide survival signals to... https://www.jove.com/v/13463 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13471.jpg Tissue Renewal without Stem Cells After cellular or tissue damage, the resident stem cells present in the human body can locally repair and regenerate the damaged tissue or organ. However, even though some tissues do not have stem cells, they can repair and regenerate with the help of pre-existing cells. For example, beta cells of the pancreas and hepatocytes of the liver can divide to renew and regenerate the tissue. Here, both cell division and cell death are well regulated by homeostasis. However, failure of such a system... https://www.jove.com/v/13471 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13480.jpg Maintenance of the ES Cell State The cells of the blastocyst inner cell mass only remain pluripotent for a short time. This state of pluripotency and self-renewal can be maintained in embryonic stem (ES) cell culture by adding specific chemicals or growth factors to ensure the cells can continue dividing and later differentiate into different cell types. In some cases, the cells are grown on a feeder layer of differentiated cells, which provides the growth factors and extracellular matrix components necessary for stem cell... https://www.jove.com/v/13480 74 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13481.jpg Somatic to iPS Cell Reprogramming Reprogramming alters the gene expression in somatic cells, transforming them into induced pluripotent stem (iPS) cells over several generations. Scientists can reprogram cells by introducing genes for four transcription factors—Oct4, Sox2, Klf4, and c-Myc (OSKM) by viral or non-viral methods. These factors are also known as Yamanaka factors after Shinya Yamanaka, who first generated iPS cells using mouse skin cells. Yamanaka was awarded the Nobel Prize in Physiology or Medicine in 2012 for this... https://www.jove.com/v/13481 89 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55515.jpg A Simple Method to Identify Kinases That Regulate Embryonic Stem Cell Pluripotency by High-throughput Inhibitor Screening Here, we present a quantitative and scalable protocol to perform targeted small molecule screens for kinase regulators of the naïve-primed pluripotent transition. https://www.jove.com/v/55515 438 2017-05-12T19:30:00+00:00 JoVE no https://visualize.jove.com/17358671-experimental-implementation-of-non-gaussian-attacks-on-a-continuous-variable-quantum-key-distribution-system monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11302.jpg The Quantum-Mechanical Model of an Atom Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of a particle moving in quantized circular orbits, Erwin Schrödinger extended de Broglie’s work by deriving what is now known as the Schrödinger equation. When Schrödinger applied his equation to hydrogen-like atoms, he was able to reproduce Bohr’s expression for the energy and, thus, the Rydberg formula governing hydrogen spectra. Schrödinger... https://www.jove.com/v/11302 165 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13571.jpg Random Variables A random variable is a single numerical value that indicates the outcome of a procedure. The concept of random variables is fundamental to the probability theory and was introduced by a Russian mathematician, Pafnuty Chebyshev, in the mid-nineteenth century. Uppercase letters such as X or Y denote a random variable. Lowercase letters like x or y denote the value of a random variable. If X is a random variable, then X is written in words, and x is given as a number. For example, let X = the... https://www.jove.com/v/13571 69 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13577.jpg Poisson Probability Distribution A Poisson probability distribution is a discrete probability distribution. It gives the probability of a number of events occurring in a fixed interval of time or space if these events happen at a known average rate and independently of the time since the last event. For example, a book editor might be interested in the number of words spelled incorrectly in a particular book. It might be that, on average, there are five words spelled incorrectly in 100 pages. The interval is 100 pages. The... https://www.jove.com/v/13577 69 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14167.jpg Maxwell-Boltzmann Distribution: Problem Solving Individual molecules in a gas move in random directions, but a gas containing numerous molecules has a predictable distribution of molecular speeds, which is known as the Maxwell-Boltzmann distribution, f(v). This distribution function f(v) is defined by saying that the expected number N (v1,v2) of particles with speeds between v1 and v2 is given by Since N is dimensionless and the unit of f(v) is seconds per meter, the equation can be conveniently modified into a differential form: Consider... https://www.jove.com/v/14167 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14511.jpg Propagation of Uncertainty from Random Error An experiment often consists of more than a single step. In this case, measurements at each step give rise to uncertainty. Because the measurements occur in successive steps, the uncertainty in one step necessarily contributes to that in the subsequent step. As we perform statistical analysis on these types of experiments, we must learn to account for the propagation of uncertainty from one step to the next. The propagation of uncertainty depends on the type of arithmetic operation performed on... https://www.jove.com/v/14511 59 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14512.jpg Propagation of Uncertainty from Systematic Error The atomic mass of an element varies due to the relative ratio of its isotopes. A sample's relative proportion of oxygen isotopes influences its average atomic mass. For instance, if we were to measure the atomic mass of oxygen from a sample, the mass would be a weighted average of the isotopic masses of oxygen in that sample. Since a single sample is not likely to perfectly reflect the true atomic mass of oxygen for all the molecules of oxygen on Earth, the mass we obtain from this particular... https://www.jove.com/v/14512 70 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51224.jpg Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators We describe the reliable generation of non-Gaussian states of traveling optical fields, including single-photon states and coherent state superpositions, using a conditional preparation method operated on the non-classical light emitted by optical parametric oscillators. Type-I and type-II phase-matched oscillators are considered and common procedures, such as the required frequency filtering or the high-efficiency quantum state characterization by homodyning, are detailed. https://www.jove.com/v/51224 563 2014-05-30T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57517.jpg Generation and Coherent Control of Pulsed Quantum Frequency Combs A protocol is presented for the practical generation and coherent manipulation of high-dimensional frequency-bin entangled photon states using integrated micro-cavities and standard telecommunications components, respectively. https://www.jove.com/v/57517 402 2018-06-08T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64930.jpg Large Scale Energy Efficient Sensor Network Routing Using a Quantum Processor Unit This study provides a method to use a quantum processor unit to compute the routes for various traffic dynamics that work to outperform classical methods in literature to maximize network lifetime. https://www.jove.com/v/64930 330 2023-09-08T21:35:00+00:00 JoVE no https://visualize.jove.com/17363404-matched-follow-up-study-of-5-8-year-old-icsi-singletons-comparison-of-their-neuromotor-development-to-ivf-and-naturally-conceived-singletons monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10981.jpg Sex Linked Disorders Like autosomes, sex chromosomes contain a variety of genes necessary for normal body function. When a mutation in one of these genes results in biological deficits, the disorder is considered sex-linked. Y chromosome mutations are called “Y-linked” and only affect males since they alone carry a copy of that chromosome. Mutations to the relatively small Y chromosome can impact male sexual function and secondary sex characteristics. Y-chromosome infertility is a disorder that affects sperm... https://www.jove.com/v/11982 103 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16314.jpg In Vitro Fertilization In vitro fertilization (IVF) is a form of assisted reproductive technology where an egg is fertilized with sperm in a controlled laboratory environment before transferring the resulting embryo into the uterus. This process is designed to help individuals and couples experiencing difficulties conceiving. The IVF process begins with ovarian stimulation, during which reproductive endocrinologists prescribe hormonal medications to stimulate the ovaries to produce multiple eggs instead of the single... https://www.jove.com/v/16314 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16317.jpg Infertility in Males Male infertility affects millions of couples worldwide, arising from various factors that impact different stages of the reproductive process. An endocrine imbalance resulting from conditions like hypogonadism, Klinefelter syndrome, or pituitary disorders can disrupt hormone levels and reduce sperm production. Testicular defects, such as tumors, cryptorchidism, atrophic testes, abnormal sperm morphology, and low sperm count or motility, may arise due to genetic factors, structural... https://www.jove.com/v/16317 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17613.jpg Longitudinal Studies Longitudinal studies are also widely used in other medical and social science fields. For instance, in cardiovascular research, they can monitor patients' health over decades to identify risk factors for heart disease, such as high cholesterol or smoking, and evaluate the long-term effectiveness of preventive measures. Similarly, in mental health studies, researchers might follow individuals from adolescence into adulthood to understand the development and progression of conditions like... https://www.jove.com/v/17613 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18564.jpg Socioemotional Development during Infancy Socio-emotional development in infancy is primarily shaped by early emotional responses and social connections, with temperament playing a central role. Temperament refers to the consistent patterns in an individual's emotional and behavioral responses, observable even in infancy. By examining temperament, researchers can better understand an infant's unique ways of interacting with the world, influencing subsequent personality and socio-emotional growth. Primary Temperament Types Stella Chess... https://www.jove.com/v/18564 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60058.jpg Human Egg Maturity Assessment and Its Clinical Application We provide an outline of the clinical protocol for non-invasive assessment of human egg maturity using polarized light microscopy. https://www.jove.com/v/60058 531 2019-08-19T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65898.jpg Mouse Round Spermatid Injection Here, we introduce a method for performing round spermatid injection (ROSI) in mice, a technique with promising clinical applications and utility for investigating the mechanisms underlying embryonic development. https://www.jove.com/v/65898 521 2024-01-26T21:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66212.jpg Monitoring Blood Glucose in Mouse Offspring After Intracytoplasmic Sperm Injection Here, we present a protocol to establish an intracytoplasmic sperm injection (ICSI)-embryo transfer (ET) mouse model, allowing us to observe age-related changes in glucose metabolism that may be attributed to ICSI, providing insights into its potential long-term impacts on human development. https://www.jove.com/v/66212 371 2024-05-17T20:40:00+00:00 JoVE no https://visualize.jove.com/17391524-normalization-of-two-channel-microarrays-accounting-for-experimental-design-and-intensity-dependent-relationships monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12014.jpg DNA Microarrays Microarrays are high-throughput and relatively inexpensive assays that can be automated to analyze large quantities of data at a time. They are used in genome-wide studies to compare gene or protein expression under two varied conditions, such as healthy and diseased states. Microarrays consist of glass or silica slides on which probe molecules are covalently attached through surface functionalization. Most commonly, the slides are prepared through the chemisorption of silanes to silica... https://www.jove.com/v/12014 154 JoVE no https://cloudfront.jove.com/files/ftp_upload/40773/40773_article_thumb_40773_TN.jpg Methods of Medium Optimization Optimizing growth media enhances microbial proliferation and maximizes product yield. Statistical experimental design methodologies provide structured and reproducible approaches, offering progressively higher levels of robustness and efficiency.The One-Factor-at-a-Time (OFAT) MethodThe One-Factor-at-a-Time (OFAT) method involves adjusting a single variable while keeping all others constant. However, it cannot detect interactions between variables, often leading to suboptimal outcomes when... https://www.jove.com/v/40773 88 2026-03-12T20:57:38+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55362.jpg A High-throughput Cell Microarray Platform for Correlative Analysis of Cell Differentiation and Traction Forces Cell differentiation is regulated by a host of microenvironmental factors, including both matrix composition and substrate material properties. We describe here a technique utilizing cell microarrays in conjunction with traction force microscopy to evaluate both cell differentiation and biomechanical cell–substrate interactions as a function of microenvironmental context. https://www.jove.com/v/55362 724 2017-03-01T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58957.jpg Using Microarrays to Interrogate Microenvironmental Impact on Cellular Phenotypes in Cancer The purpose of the method presented here is to show how microenvironment microarrays (MEMA) can be fabricated and used to interrogate the impact of thousands of simple combinatorial microenvironments on the phenotype of cultured cells. https://www.jove.com/v/58957 500 2019-05-21T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61564.jpg Mapping the Structure-Function Relationships of Disordered Oncogenic Transcription Factors Using Transcriptomic Analysis Intrinsically disordered domains are important for oncogenic fusion transcription factor function. To therapeutically target these proteins, a more detailed understanding of the regulatory mechanisms employed by these domains is required. Here, we use transcriptomics to map important structural features of the intrinsically disordered EWS domain in Ewing sarcoma. https://www.jove.com/v/61564 598 2020-06-27T22:00:00+00:00 JoVE no https://visualize.jove.com/17411240-two-parameter-families-of-strange-attractors monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11305.jpg The Pauli Exclusion Principle The arrangement of electrons in the orbitals of an atom is called its electron configuration. We describe an electron configuration with a symbol that contains three pieces of information: The number of the principal quantum shell, n, The letter that designates the orbital type (the subshell, l), and A superscript number that designates the number of electrons in that particular subshell. For example, the notation 2p4 indicates four electrons in a p subshell (l = 1) with a principal... https://www.jove.com/v/11305 186 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14245.jpg Categories of Equilibrium Equilibrium is a crucial concept in physics, enabling us to understand how forces interact with bodies to produce no or constant motion. In two-dimensional equilibrium, force systems can be classified into different categories based on their characteristics. One of the categories of equilibrium is collinear equilibrium, which involves forces acting along a straight line. This type of equilibrium requires only one force equation in the direction of the forces, as the other equations are... https://www.jove.com/v/14245 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14361.jpg One-Degree-of-Freedom System In mechanical engineering, one-degree-of-freedom systems form the basis of a wide range of electrical and mechanical components. Using these models, engineers can predict the behavior of various parts in a larger system, which gives them insight into how different forces interact with each other. A one-degree-of-freedom system is defined by an independent variable that determines its state and behavior. One example of a one-degree-of-freedom system is a simple harmonic oscillator, such as a... https://www.jove.com/v/14361 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16058.jpg Pole and System Stability The transfer function is a fundamental concept representing the ratio of two polynomials. The numerator and denominator encapsulate the system's dynamics. The zeros and poles of this transfer function are critical in determining the system's behavior and stability. Simple poles are unique roots of the denominator polynomial. Each simple pole corresponds to a distinct solution to the system's characteristic equation, typically resulting in exponential decay terms in the system's response.<br... https://www.jove.com/v/16058 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16124.jpg Root Loci for Positive-Feedback Systems The Hartley oscillator is a positive feedback system that sustains oscillations by feeding the output back to the input in phase, thereby reinforcing the signal. Positive feedback systems can be viewed as negative feedback systems with inverted feedback signals. In these systems, the root locus encompasses all points on the s-plane where the angle of the system transfer function equals 360 degrees. The construction rules for the root locus in positive feedback systems are similar to those in... https://www.jove.com/v/16124 83 JoVE no https://cloudfront.jove.com/files/ftp_upload/40600/40600_article_thumb_40600_TN.jpg Orthogonal Trajectories Orthogonal trajectories describe the geometric relationship between two families of curves that intersect each other at right angles. One illustrative case involves a family of parabolas that open sideways along the x-axis. These curves share a common shape but differ by a scaling parameter, resulting in a set of curves that all pass through the origin and widen at different rates.Determining Orthogonal TrajectoriesTo identify the orthogonal trajectories for these parabolas, the first step... https://www.jove.com/v/40600 86 2026-01-29T17:33:09+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50419.jpg Setting Limits on Supersymmetry Using Simplified Models This paper demonstrates a protocol for recasting experimental simplified model limits into conservative and aggressive limits on an arbitrary new physics model. Publicly available LHC experimental results can be recast in this manner into limits on almost any new physics model with a supersymmetry-like signature. https://www.jove.com/v/50419 466 2013-11-16T00:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59149.jpg Generating Strictly Controlled Stimuli for Figure Recognition Experiments This protocol describes a method for an experiment that examines whether specific graph and non-graph properties (features) are relevant to the recognition of figures. The method uses a database that stores various feature values of respective figures called (6 point, n line) figures. https://www.jove.com/v/59149 339 2019-03-18T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68955.jpg Age-dependent Dynamics of Locomotion in Caenorhabditis elegans : A Lyapunov Exponent Analysis This study examines the effect of age on locomotion in C. elegans by measuring the largest Lyapunov exponent (LLE). As they age, C. elegans show an increase and subsequent decline in motor control. Results show a peak LLE at five days, followed by a decline as the worms age. https://www.jove.com/v/68955 404 2025-09-23T21:45:00+00:00 JoVE no https://visualize.jove.com/17416308-automated-solutions-for-total-rna-isolation-from-diverse-sample-types monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12022.jpg RNA-seq RNA sequencing, or RNA-Seq, is a high-throughput sequencing technology used to study the transcriptome of a cell. Transcriptomics helps to interpret the functional elements of a genome and identify the molecular constituents of an organism. Additionally, it also helps in understanding the development of an organism and the occurrence of diseases. Before the discovery of RNA-seq, microarray-based methods and Sanger sequencing were used for transcriptome analysis. However, while microarray-based... https://www.jove.com/v/12022 201 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50356.jpg High-throughput, Automated Extraction of DNA and RNA from Clinical Samples using TruTip Technology on Common Liquid Handling Robots TruTip is a simple nucleic acid extraction technology whereby a porous, monolithic binding matrix is inserted into a pipette tip. Consequently, the sample preparation format is compatible with most liquid handling instruments, and can be used for many medium to high-throughput clinical applications and sample types. https://www.jove.com/v/50356 647 2013-06-11T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52510.jpg RNA Isolation from Cell Specific Subpopulations Using Laser-capture Microdissection Combined with Rapid Immunolabeling Gene expression analysis of a subset of cells in a specific tissue represents a major challenge. This article describes how to isolate high-quality total RNA from a specific cell population by combining a rapid immunolabeling method with laser capture microdissection. https://www.jove.com/v/52510 421 2015-04-11T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63143.jpg Isolate Cell-Type-Specific RNAs from Snap-Frozen Heterogeneous Tissue Samples without Cell Sorting This protocol aims to isolate cell-type-specific translating ribosomal mRNAs using the NuTRAP mouse model. https://www.jove.com/v/63143 510 2021-12-08T22:00:00+00:00 JoVE no https://visualize.jove.com/17427735-atlas-renormalization-for-improved-brain-mr-image-segmentation-across-scanner-platforms monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/57256.jpg Whole-brain Segmentation and Change-point Analysis of Anatomical Brain MRI—Application in Premanifest Huntington's Disease This paper describes a statistical model for volumetric MRI data analysis, which identifies the "change-point" when brain atrophy begins in premanifest Huntington's disease. Whole-brain mapping of the change-points is achieved based on brain volumes obtained using an atlas-based segmentation pipeline of T1-weighted images. https://www.jove.com/v/57256 546 2018-06-09T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58198.jpg Automated Segmentation of Cortical Grey Matter from T1-Weighted MRI Images This protocol describes the process of applying seven different automated segmentation tools to structural T1-weighted MRI scans to delineate grey matter regions that can be used for the quantification of grey matter volume. https://www.jove.com/v/58198 408 2019-01-07T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59653.jpg Brain Infarct Segmentation and Registration on MRI or CT for Lesion-symptom Mapping Provided here is a practical tutorial for an open-access, standardized image processing pipeline for the purpose of lesion-symptom mapping. A step-by-step walkthrough is provided for each processing step, from manual infarct segmentation on CT/MRI to subsequent registration to standard space, along with practical recommendations and illustrations with exemplary cases. https://www.jove.com/v/59653 625 2019-09-25T20:00:00+00:00 JoVE no https://visualize.jove.com/17436764-creating-order-from-chaos-part-i-triage-initial-care-and-tactical-considerations-in-mass-casualty-and-disaster-response monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13546.jpg Planning Nursing Care I The planning phase of the nursing process helps nurses set priorities, outline patient-centered goals and expected outcomes, and tailor nursing interventions to align with the aligned care plan. Through the planning phase, the nurse applies critical thinking skills to align and develop interventions according to the patient's needs. It provides continuity of care allowing patients to receive the maximum benefit from treatment. It serves as a pilot plan for allocating individual staff to a... https://www.jove.com/v/13546 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16369.jpg Flail Chest-II Managing flail chest, a condition characterized by a segment of the chest wall moving independently from the rest of the thoracic cage, requires a comprehensive approach. It includes a thorough assessment of the patient's condition, a diagnostic evaluation to determine the extent of the injury, and the implementation of appropriate medical interventions tailored to the individual's needs. Assessment: 1. Clinical Evaluation: History: • Nurses obtain a detailed history of the traumatic event,... https://www.jove.com/v/16369 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/17931/17931_article_thumb_17931.jpg Acute Coronary Syndrome IV: Interprofessional Care IntroductionThe management of Acute Coronary Syndrome (ACS) aims to minimize myocardial damage, preserve myocardial function, and prevent complications.Initial ManagementInpatient management involves continuous cardiac monitoring, preferably in an ICU, focusing on blood pressure, serum sodium, potassium, and creatinine levels, and urine output. Ongoing pharmacologic management is crucial for stabilizing the patient.Supplemental Oxygen: Administer supplemental oxygen if oxygen saturation is... https://www.jove.com/v/17931 88 2025-06-19T16:29:05+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17948/17948_article_thumb_17948.jpg Cardiopulmonary Resuscitation III: AED Use Introduction to AEDAn Automated External Defibrillator (AED) is a portable medical device that analyzes the heart's rhythm and, if necessary, delivers an electrical shock to help the heart re-establish an effective rhythm during sudden cardiac arrest (SCA). SCA occurs when the heart suddenly and unexpectedly stops beating, leading to a loss of blood flow to the brain and other vital organs. In such emergencies, time is of the essence, and using an AED, combined with Cardiopulmonary... https://www.jove.com/v/17948 83 2025-06-19T16:38:36+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17949/17949_article_thumb_17949.jpg Cardiopulmonary Resuscitation IV: Pharmacological Management Pharmacologic intervention is crucial in treating cardiac arrest patients during ACLS or Advanced Cardiovascular Life Support. The ACLS algorithms guide the administration of specific drugs based on the patient's cardiac arrest rhythm, which includes pulseless ventricular tachycardia (VT), ventricular fibrillation (VF), asystole, and pulseless electrical activity (PEA).EpinephrineIndication: Epinephrine is the first-line drug for all cardiac arrest rhythms.Mechanism of Action: Epinephrine... https://www.jove.com/v/17949 85 2025-07-31T20:24:37+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18141/18141_article_thumb_18141.jpg Applications of GIS: Disaster Management and Emergency Response Geographic Information System (GIS) technology is essential for risk identification, action prioritization, and resource optimization in critical situations like flooding and earthquakes. By integrating spatial and demographic data, GIS provides a comprehensive framework for emergency response.GIS integrates data layers, like rainfall intensity, topography, elevation profiles, and river levels, to model high-risk flood zones. These layers assess areas susceptible to flooding based on their... https://www.jove.com/v/18141 89 2025-03-26T22:42:44+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50534.jpg Prehospital Thrombolysis: A Manual from Berlin Identification of suspected stroke in the dispatch center of the Berlin Fire Brigade prompts the deployment of a CT-equipped ambulance. If ischemic stroke is confirmed and contraindications are excluded prehospital thrombolysis is applied. https://www.jove.com/v/50534 352 2013-11-27T03:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54737.jpg Integrated Compensatory Responses in a Human Model of Hemorrhage The purpose of this protocol is to demonstrate the techniques for measuring compensatory responses to reduced central blood volume using lower body negative pressure as a noninvasive experimental model of human hemorrhage which can be used to quantify the total integration of compensatory mechanisms to blood volume deficit in humans. https://www.jove.com/v/54737 477 2016-11-20T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55138.jpg Setting Up a Stroke Team Algorithm and Conducting Simulation-based Training in the Emergency Department - A Practical Guide Every min counts in acute stroke care. This guide shows how to establish a Stroke Team algorithm and enhance its performance with regular simulation training. The principles of Crew Resource Management (CRM) facilitate a straight workflow, reduce door-to-needle times and increase staff satisfaction. https://www.jove.com/v/55138 592 2017-01-15T22:00:00+00:00 JoVE no https://visualize.jove.com/17451745-crystal-structure-and-allosteric-regulation-of-the-cytoplasmic-escherichia-coli-l-asparaginase-i monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2094.jpg An Assay for Measuring the Activity of Escherichia coli Inducible Lysine Decarboxyase The activity of the inducible lysine decarboxylase is monitored by reacting the substrate L-lysine and the product cadaverine with 2,4,6-trinitrobenzensulfonic acid to form adducts that have differential solubility in toluene. https://www.jove.com/v/2094 488 2010-12-20T01:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/4266.jpg Iterative Optimization of DNA Duplexes for Crystallization of SeqA-DNA Complexes Crystal structure of protein–DNA complexes can provide insight into protein function, mechanism, as well as, the nature of the specific interaction. Here, we report how to optimize the length, sequence and ends of duplex DNA for co-crystallization with Escherichia coli SeqA, a negative regulator of replication initiation. https://www.jove.com/v/4266 702 2012-11-01T22:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10974.jpg Allosteric Regulation Allosteric regulation of enzymes occurs when the binding of an effector molecule to a site that is different from the active site causes a change in the enzymatic activity. This alternate site is called an allosteric site, and an enzyme can contain more than one of these sites. Allosteric regulation can either be positive or negative, resulting in an increase or decrease in enzyme activity. Most enzymes that display allosteric regulation are metabolic enzymes involved in the degradation or... https://www.jove.com/v/10974 68 2025-10-23T18:48:33+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10974.jpg Allosteric Regulation Allosteric regulation of enzymes occurs when the binding of an effector molecule to a site that is different from the active site causes a change in the enzymatic activity. This alternate site is called an allosteric site, and an enzyme can contain more than one of these sites. Allosteric regulation can either be positive or negative, resulting in an increase or decrease in enzyme activity. Most enzymes that display allosteric regulation are metabolic enzymes involved in the degradation or... https://www.jove.com/v/11515 68 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11516.jpg Ligand Binding and Linkage Allosteric proteins have more than one ligand binding site; the binding of a ligand to any of these sites influences the binding of ligands to the other sites. When a protein is allosteric, its binding sites are called coupled or linked. In the case of enzymes, the site that binds to the substrate is known as the active site and the other site is known as the regulatory site. When a ligand binds to the regulatory site, this leads to conformational changes in the protein that can influence the... https://www.jove.com/v/11516 49 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12221.jpg Allosteric Proteins-ATCase Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor. Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,... https://www.jove.com/v/12221 79 JoVE no https://cloudfront.jove.com/files/ftp_upload/19533/19533_article_thumb_19533.jpg Inducible Operons: lac Operon The lac operon in Escherichia coli is a model for understanding inducible gene regulation and metabolic flexibility. It integrates local control by lactose and global regulation through catabolite repression, enabling E. coli to preferentially metabolize glucose when available and switch to lactose utilization when glucose is scarce.Structure and Function of the lac OperonThe lac operon contains three structural genes: lacZ (β-galactosidase), lacY (lactose permease), and lacA (thiogalactoside... https://www.jove.com/v/19533 85 2025-06-12T16:14:20+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19541/19541_article_thumb_19541.jpg Stringent Response in E. coli Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs... https://www.jove.com/v/19541 83 2025-06-12T16:16:17+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55022.jpg Production, Crystallization and Structure Determination of C. difficile PPEP-1 via Microseeding and Zinc-SAD Proline-proline endopeptidase-1 (PPEP-1) is a secreted metalloprotease and promising drug-target from the human pathogen Clostridium difficile. Here we describe all methods necessary for the production and structure determination of this protein. https://www.jove.com/v/55022 814 2016-12-30T23:00:00+00:00 JoVE no https://visualize.jove.com/17464329-novel-role-of-hdac-inhibitors-in-aml1eto-aml-cells-activation-of-apoptosis-and-phagocytosis-through-induction-of-annexin-a1 monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12426.jpg Apoptosis Apoptosis is a combination of two Greek words, 'apo' and 'ptosis,' meaning separation and falling off, respectively. Hippocrates used this word to describe gangrene, which was caused due to bandaging of fractured bones. Apoptosis was distinguished from necrosis in 1970 when John Kerr reported observations of morphological changes occurring during apoptosis. During one experiment, he observed that the disruption of blood supply to the liver tissue resulted in a size reduction of the tissue. https://www.jove.com/v/12426 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12428.jpg The Extrinsic Apoptotic Pathway The extrinsic apoptotic pathway is initiated when extracellular death-inducing signals, such as specific cytokines, activate the death receptors expressed on the cell surface. The immune cells involved in this pathway are natural killer cells (NK cells) and cytotoxic T-lymphocytes. NK cells are critical in innate immune response, while cytotoxic T-lymphocytes are associated with adaptive immune response. These cells recognize specific receptors expressed on the altered cells and activate... https://www.jove.com/v/12428 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12429.jpg The Intrinsic Apoptotic Pathway Internal cellular stress, such as cellular injury or hypoxia, triggers intrinsic apoptosis. The B-cell lymphoma 2 (Bcl-2) family of proteins are the primary regulators of the intrinsic apoptotic pathway. For example, during DNA damage, checkpoint proteins, such as Ataxia Telangiectasia Mutated (ATM protein) and Checkpoints Factor-2 (Chk2) proteins, are activated. These proteins phosphorylate p53 which further activates pro-apoptotic proteins, such as Bax, Bak, PUMA, and Noxa, and inhibits... https://www.jove.com/v/12429 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12430.jpg Phagocytosis of Apoptotic Cells Cells undergoing apoptosis form apoptotic bodies that must be removed immediately to prevent inflammation, autoimmune diseases, and necrosis. Phagocytosis is carried out by professional phagocytes such as macrophages or immature dendritic cells. Non-professional phagocytes such as epithelial cells and fibroblasts also take part in this process; however, they are not as effective as professional phagocytes. Normal cells contain receptors that prevent them from being recognized by phagocytes. https://www.jove.com/v/12430 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15335.jpg Cells of the Innate Immune Response The innate immune response is an immediate and non-specific response against pathogens, acting swiftly to prevent the spread of infections. The primary cells involved in this response are phagocytes and natural killer (NK) cells. Phagocytes Phagocytes police the peripheral tissues by removing cellular debris and responding to the invasion of foreign substances or pathogens. Many phagocytes attack and remove microorganisms even before lymphocytes detect them. The human body has two general... https://www.jove.com/v/15335 88 JoVE no https://cloudfront.jove.com/files/ftp_upload/40878/40878_article_thumb_40878.jpg Cellular Injury V: Apoptosis and Autophagy Cells respond to damage and stress through highly coordinated processes that decide whether they survive or undergo controlled self-destruction. Two major pathways involved in this regulation are apoptosis, a type of programmed cell death, and autophagy, a survival mechanism that helps cells adapt to adverse conditions.ApoptosisApoptosis removes aged or injured cells to maintain tissue balance. During this process, the cell shrinks, chromatin condenses and fragments, and membrane-bound... https://www.jove.com/v/40878 82 2026-04-13T21:37:26+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55135.jpg Genome-wide Analysis of HDAC Inhibitor-mediated Modulation of microRNAs and mRNAs in B Cells Induced to Undergo Class-switch DNA Recombination and Plasma Cell Differentiation Epigenetic factors can interact with genetic programs to modulate gene expression and regulate B cell function. By combining in vitro B-cell stimulation, qRT-PCR, and high-throughput microRNA-sequence and mRNA-sequence approaches, we can analyze the epigenetic modulation of miRNA and gene expression in B cells. https://www.jove.com/v/55135 666 2017-09-20T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55878.jpg Simultaneous Measurement of HDAC1 and HDAC6 Activity in HeLa Cells Using UHPLC-MS The present method serves to identify isoform-specific inhibitors of histone deacetylases (HDAC) in HeLa cells by the UHPLC-MS analysis of multiple substrates. This is an antibody-free method developed to reflect HDAC1 and HDAC6 activity in the living cell environment, in contrast to single-isoform cell-free assays. https://www.jove.com/v/55878 560 2017-08-10T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68244.jpg Intracellular Phosphoflow Cytometry of Acute Myeloid Leukemia Patient-Derived Xenotransplants Here, a phosphoflow cytometry-based method is described to analyze signaling downstream of the mTORC1, JAK/STAT5, and MAPK pathways in acute human myeloid leukemia cells xenografted into mice and obtained from bone marrow aspirates. p-STAT5, p-4EBP1, p-RPS6, and p-ERK1/2 levels are simultaneously measured using a next-generation spectral flow cytometer with high sensitivity. https://www.jove.com/v/68244 458 2025-06-06T22:35:00+00:00 JoVE no https://visualize.jove.com/17491469-oriented-speckle-reducing-anisotropic-diffusion monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/50427.jpg Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases Diffusion tensor imaging (DTI) basically serves as an MRI-based tool to identify in vivo the microstructure of the brain and pathological processes due to neurological disorders within the cerebral white matter. DTI-based analyses allow for application to brain diseases both at the group level and in single subject data. https://www.jove.com/v/50427 573 2013-07-28T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54419.jpg Controlled Synthesis and Fluorescence Tracking of Highly Uniform Poly( N -isopropylacrylamide) Microgels Non-stirred precipitation polymerization provides a rapid, reproducible prototyping approach to the synthesis of stimuli-sensitive poly(N-isopropylacrylamide) microgels of narrow size distribution. In this protocol synthesis, light scattering characterization and single particle fluorescence tracking of these microgels in a wide-field microscopy setup are demonstrated. https://www.jove.com/v/54419 694 2016-09-08T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68576.jpg Applying Permanent, Robust Stenciled Patterns of Fine Particles to Elastomeric Surfaces We present a method to apply permanent markings and patterns to silicone surfaces by adhering fine particles to the surface. The markings can be either a recognizable design or a random speckle pattern such as those used in digital image correlation. https://www.jove.com/v/68576 432 2025-07-08T21:10:00+00:00 JoVE no https://visualize.jove.com/17496645-performance-and-preference-for-ace-stimulation-rates-obtained-with-nucleus-rp-8-and-freedom-system monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1730.jpg Programmed Electrical Stimulation in Mice Programmed electrical stimulation provides the ability to determine conduction properties of the heart, and the possibility to induce and terminate cardiac arrhythmias using various pacing protocols. Using a transvenous catheter, intracardiac electrogram recordings can be obtained in mice following programmed electrical stimulation protocols to identify arrhythmogenic substrates. https://www.jove.com/v/1730 449 2010-05-27T00:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13285.jpg Pulse amplitude and quality Pulse amplitude is a crucial indicator of cardiac health because it provides valuable insights into the strength of left ventricular contractions and the overall uniformity of blood circulation within the vasculature. The strength of the pulse is directly related to the force with which the heart contracts and the volume of blood being pumped. A weak or absent pulse may indicate reduced cardiac output or poor left ventricular contraction, which can be signs of cardiovascular dysfunction or... https://www.jove.com/v/13285 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13287.jpg Pulse Assessment Sites Pulse assessment sites are crucial in evaluating a patient's cardiovascular health. By assessing the pulsations of arteries at specific anatomical locations, healthcare professionals can gather valuable information about blood flow, heart rate, and peripheral circulation. Understanding these pulse assessment sites is essential for conducting comprehensive cardiovascular evaluations and monitoring patients' overall health. These sites are strategically chosen due to the accessibility and... https://www.jove.com/v/13287 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14847.jpg Motor Unit Stimulation When the neuron of a motor unit fires an action potential, it triggers a series of events, leading to a twitch contraction in the muscle fibers. The process of excitation-contraction coupling is crucial in relaying the action potential to the muscle fibers. The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the... https://www.jove.com/v/14847 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14848.jpg Muscle Stimulation Frequency The contraction strength of muscles is regulated by motor neurons, which modulate the frequency of action potentials dispatched to the motor units based on the body's requirements. This process of varying the muscle stimulation frequency allows muscles to contract with a force that is precisely tailored to the needs of the moment, whether lifting a feather or a heavy box. Wave summation At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches... https://www.jove.com/v/14848 82 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51403.jpg Controlling Parkinson's Disease With Adaptive Deep Brain Stimulation Adaptive deep brain stimulation (aDBS) is effective for Parkinson’s disease, improving symptoms and reducing power consumption compared to conventional deep brain stimulation (cDBS). In aDBS we track a local field potential biomarker (beta oscillatory amplitude) in real time and use this to control the timing of stimulation. https://www.jove.com/v/51403 672 2014-07-16T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61128.jpg Preparation of Peripheral Nerve Stimulation Electrodes for Chronic Implantation in Rats Existing approaches for constructing chronically implantable peripheral nerve cuff electrodes for use in small rodents often require specialized equipment and/or highly trained personnel. In this protocol we demonstrate a simple, low-cost approach for fabricating chronically implantable cuff electrodes, and demonstrate their effectiveness for vagus nerve stimulation (VNS) in rats. https://www.jove.com/v/61128 579 2020-07-14T20:00:00+00:00 JoVE no https://visualize.jove.com/17496672-a-randomized-controlled-trial-evaluating-the-active-communication-education-program-for-older-people-with-hearing-impairment monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13510.jpg Therapeutic Communication Communication is a lifelong learning process. Through therapeutic communication, nurses can collect relevant assessment data, provide education and counseling, and interact during nursing interventions. Sending and receiving messages occur through verbal and nonverbal communication techniques and can happen separately or simultaneously. Verbal communication depends on language or a prescribed way of using words so that people can share information effectively. The critical aspects of verbal... https://www.jove.com/v/13510 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13519.jpg Barriers to Effective Communication II The barriers to effective communication also include cultural barriers, semantic barriers, gender barriers, and time constraints. Cultural barriers: Differences in values, beliefs, religion, knowledge, and tradition can significantly impact communication. Awareness of nonverbal cues is critical, especially when conversing with a patient from a different culture. What appears appropriate in one culture may be inappropriate in another. Semantic barriers: As a result of their tendency to use... https://www.jove.com/v/13519 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18637.jpg Community Based Intervention Community-based interventions in mental health represent a paradigm shift from institution-centered care to treatments embedded within the fabric of local communities. By prioritizing inclusion and leveraging existing societal structures, this approach fosters a supportive environment conducive to addressing mental health challenges while promoting individual dignity and agency. Foundations of Community Mental Health Programs Central to the success of community-based interventions is the... https://www.jove.com/v/18637 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58798.jpg E-Patient Counseling Trial (E-PACO): Computer Based Education versus Nurse Counseling for Patients to Prepare for Colonoscopy The aim of this trial is to establish the position of online computer-based education as a tool for patient preparation prior to a colonoscopy. Computer based education is compared with the standard of care, nurse counseling, evaluating endoscopic quality measures and patient related outcome measures. https://www.jove.com/v/58798 388 2019-08-01T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60804.jpg Working Memory Training for Older Participants: A Control Group Training Regimen and Initial Intellectual Functioning Assessment A cognitive training intervention in elderly population together with the assessment of the pre training cognitive abilities is presented. We show two versions of training - experimental and active control - and demonstrate their effects on the array of cognitive tests. https://www.jove.com/v/60804 421 2020-09-20T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64552.jpg Systematic Hearing Performance Evaluation Process for Adolescents with Cochlear Implantation at Early Ages This paper describes a battery of tests used to clinically assess the hearing performance of adolescent, Mandarin-speaking, experienced cochlear implant users upgraded to a new fine structure coding strategy. The battery of tests include speech in quiet conditions, speech in noisy conditions, lexical tone, and music perception. https://www.jove.com/v/64552 364 2023-03-24T21:10:00+00:00 JoVE no https://visualize.jove.com/17512788-predicting-effective-continuous-positive-airway-pressure-in-sleep-apnea-using-an-artificial-neural-network monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15706.jpg Neural Control of Respiration The neural regulation of respiration is a meticulously coordinated process primarily controlled by the respiratory centers located within the brainstem. These centers, composed of specialized neurons, transmit nerve impulses that control the contraction and relaxation of our respiratory muscles. Respiratory Centers in the Brainstem Two primary areas comprise the respiratory center: the medullary respiratory center in the medulla oblongata and the pontine respiratory group in the pons. The... https://www.jove.com/v/15706 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16400.jpg Mechanical Ventilation III: Noninvasive Ventilation Noninvasive positive-pressure ventilation (NIPPV), continuous positive airway pressure (CPAP), and bilevel positive airway pressure (BiPAP) are essential methods in respiratory care. These ventilation techniques offer unique benefits for patients with various respiratory conditions, providing adequate support without requiring intubation. Let's explore how each method is crucial in improving patient outcomes and enhancing respiratory therapy. Noninvasive Positive-Pressure Ventilation (NIPPV)<br... https://www.jove.com/v/16400 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17797.jpg Sleep Apnea Sleep apnea is a condition where breathing stops intermittently during sleep, often leading to significant health issues. Each episode can last from 10 to 20 seconds or more and is frequently accompanied by a brief arousal from sleep. This disturbance, largely unnoticed by the individual, can lead to severe daytime fatigue. Commonly, individuals seek help after being informed by their partners about loud snoring and noticeable breathing pauses during sleep. The condition is more prevalent among... https://www.jove.com/v/17797 81 JoVE no https://cloudfront.jove.com/files/ftp_upload/17947/17947_article_thumb_17947.jpg Cardiopulmonary Resuscitation II: ACLS Airway Management Airway management is a key skill in emergency and critical care settings, as maintaining a clear airway is essential for adequate oxygenation and ventilation.Head Tilt-Chin Lift TechniqueThe head tilt-chin lift maneuver is an essential technique primarily used in patients without suspected cervical spine injuries. To perform this maneuver, one hand is placed on the patient’s forehead, and gentle pressure is applied backward to tilt the head. The fingertips of the other hand are positioned under... https://www.jove.com/v/17947 82 2025-06-19T16:38:19+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54933.jpg A Model to Simulate Clinically Relevant Hypoxia in Humans Hypoxia simulation in humans has usually been performed by inhaling hypoxic gas mixtures. For this study, apneic divers were used to simulate dynamic hypoxia in humans. Additionally, physiological changes in desaturation and re-saturation kinetics were evaluated with non-invasive tools such as Near-Infrared-Spectroscopy (NIRS) and peripheral oxygenation saturation (SpO2). https://www.jove.com/v/54933 594 2016-12-22T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65931.jpg Artificial Intelligence-Based System for Detecting Attention Levels in Students This paper proposes an artificial intelligence-based system to automatically detect whether students are paying attention to the class or are distracted. This system is designed to help teachers maintain students' attention, optimize their lessons, and dynamically introduce modifications in order for them to be more engaging. https://www.jove.com/v/65931 397 2023-12-15T22:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66950.jpg IntelliSleepScorer, a Software Package with a Graphic User Interface for Mice Automated Sleep Stage Scoring We present a software package with a graphic user interface for researchers without coding experience to score sleep stages in mice with a simple download and operation. https://www.jove.com/v/66950 294 2024-11-08T21:20:00+00:00 JoVE no https://visualize.jove.com/17537579-molecular-modeling-and-functional-analysis-of-the-atos-atoc-two-component-signal-transduction-system-of-escherichia-coli monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4056.jpg Mapping Bacterial Functional Networks and Pathways in Escherichia Coli using Synthetic Genetic Arrays Systematic, large-scale synthetic genetic (gene-gene or epistasis) interaction screens can be used to explore genetic redundancy and pathway cross-talk. Here, we describe a high-throughput quantitative synthetic genetic array screening technology, termed eSGA that we developed for elucidating epistatic relationships and exploring genetic interaction networks in Escherichia coli. https://www.jove.com/v/4056 846 2012-11-12T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/4057.jpg Identification of Protein Complexes in Escherichia coli using Sequential Peptide Affinity Purification in Combination with Tandem Mass Spectrometry Affinity purification of tagged proteins in combination with mass spectrometry (APMS) is a powerful method for the systematic mapping of protein interaction networks and for investigating the mechanistic basis of biological processes. Here, we describe an optimized sequential peptide affinity (SPA) APMS procedure developed for the bacterium Escherichia coli that can be used to isolate and characterize stable multi-protein complexes to near homogeneity even starting from low copy numbers per... https://www.jove.com/v/4057 898 2012-11-12T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19538/19538_article_thumb_19538.jpg Chemotaxis in E. coli Chemotaxis in Escherichia coli is a sensory-driven motility mechanism that enables bacteria to navigate chemical gradients, moving toward beneficial environments while avoiding harmful conditions. This process relies on a signal transduction system integrating external chemical cues with flagellar motor control.Chemoreceptors and Signal DetectionE. coli detects chemical gradients through methyl-accepting chemotaxis proteins (MCPs), which are membrane-bound chemoreceptors that sense attractants... https://www.jove.com/v/19538 87 2025-06-12T16:15:16+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57966.jpg Analyzing Protein Architectures and Protein-Ligand Complexes by Integrative Structural Mass Spectrometry Mass spectrometry (MS) has emerged as an important tool for the investigation of structure and dynamics of macromolecular assemblies. Here, we integrate MS-based approaches to interrogate protein complex formation and ligand binding. https://www.jove.com/v/57966 453 2018-10-15T22:00:00+00:00 JoVE no https://visualize.jove.com/17546540-virtual-endoscope-assisted-intracranial-aneurysm-surgery-evaluation-of-fifty-eight-surgical-cases monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17981/17981_article_thumb_17981.jpg Aneurysm III: Interprofessional Care Aneurysm management involves either conservative medical therapy or surgical intervention, depending on the size and symptoms of the aneurysm. Conservative management is generally reserved for smaller, asymptomatic aneurysms, while larger or symptomatic aneurysms often necessitate surgical repair.Conservative Medical TherapyFor small, asymptomatic aneurysms, particularly abdominal aortic aneurysms (AAA) less than 5.5 centimeters in diameter, conservative medical therapy is recommended. This... https://www.jove.com/v/17981 86 2025-06-19T16:19:25+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55522.jpg Comprehensive Endovascular and Open Surgical Management of Cerebral Arteriovenous Malformations Surgery is the gold standard for accessible arteriovenious malformations (AVMs), and pre-operative embolization can simplify this procedure. We describe our approach for staged endovascular embolization and open resection of AVMs, and provide a representative clinical example highlighting the advantages of a comprehensively trained neurovascular surgeon leading a multi-disciplinary clinical team. https://www.jove.com/v/55522 898 2017-10-20T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63738.jpg Microsurgical Creation of Giant Bifurcation Aneurysms in Rabbits for the Evaluation of Endovascular Devices Here, we describe the technique for the microsurgical creation of giant bifurcation aneurysms in rabbits for the evaluation of endovascular devices. https://www.jove.com/v/63738 441 2023-09-08T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66227.jpg Pioneering Patient-Specific Approaches for Precision Surgery Using Imaging and Virtual Reality Advancements in endovascular treatment have replaced complex open surgical procedures with minimally invasive options, like valve replacement and aneurysm repair. This paper proposes using three-dimensional (3D) modeling and virtual reality to aid in C-arm positioning, angle measurements, and roadmap generation for neuro-interventional catheterization lab procedural planning, minimizing procedure time. https://www.jove.com/v/66227 378 2024-04-05T20:20:00+00:00 JoVE no https://visualize.jove.com/17591754-autonomous-microfluidic-sample-preparation-system-for-protein-profile-based-detection-of-aerosolized-bacterial-cells-and-spores monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1603.jpg Digital Microfluidics for Automated Proteomic Processing Digital Microfluidics is a technique characterized by the manipulation of discrete droplets (~nL - mL) on an array of electrodes by the application of electrical fields. It is well-suited for carrying out rapid, sequential, miniaturized automated biochemical assays. Here, we report a platform capable of automating several proteomic processing steps. https://www.jove.com/v/1603 655 2009-11-07T00:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53051.jpg A Microfluidic Platform for Precision Small-volume Sample Processing and Its Use to Size Separate Biological Particles with an Acoustic Microdevice This protocol describes a system architecture for performing automated small volume (0.15–1.5 ml) particle separations using a microfluidic device, and discusses methods to optimize acoustofluidic device performance and operation. https://www.jove.com/v/53051 692 2015-11-23T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60489.jpg Electrowetting-based Digital Microfluidics Platform for Automated Enzyme-linked Immunosorbent Assay Electrowetting-based digital microfluidic is a technique that utilizes a voltage-driven change in the apparent contact angle of a microliter-volume droplet to facilitate its manipulation. Combining this with functionalized magnetic beads enables the integration of multiple laboratory unit operations for sample preparation and identification of pathogens using Enzyme-linked Immunosorbent Assay (ELISA). https://www.jove.com/v/60489 502 2020-02-23T20:00:00+00:00 JoVE no https://visualize.jove.com/17624546-winner-take-all-selection-in-a-neural-system-with-delayed-feedback monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3685.jpg A Fully Automated and Highly Versatile System for Testing Multi-cognitive Functions and Recording Neuronal Activities in Rodents In this report, we present a fully automated and highly versatile system capable of simultaneously testing multi-cognitive behaviors and recording neuronal activities for rodents. https://www.jove.com/v/3685 553 2012-05-03T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10835.jpg Neural Regulation Digestion begins with a cephalic phase that prepares the digestive system to receive food. When our brain processes visual or olfactory information about food, it triggers impulses in the cranial nerves innervating the salivary glands and stomach to prepare for food. The cephalic phase is a conditioned or learned response to familiar foods. Our appetite or desire for a particular food modifies the preparatory responses directed by the brain. Individuals may produce more saliva and stomach... https://www.jove.com/v/10835 97 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12415.jpg Woodward–Hoffmann Selection Rules and Microscopic Reversibility Electrocyclic reactions, cycloadditions, and sigmatropic rearrangements are concerted pericyclic reactions that proceed via a cyclic transition state. These reactions are stereospecific and regioselective. The stereochemistry of the products depends on the symmetry characteristics of the interacting orbitals and the reaction conditions. Accordingly, pericyclic reactions are classified as either symmetry-allowed or symmetry-forbidden. Woodward and Hoffmann presented the selection criteria for... https://www.jove.com/v/12415 94 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14900.jpg Neural Circuits Neural circuits and neuronal pools are two of the main structures found in the nervous system. Neural circuits are networks of neurons that work together to carry out a specific task or process. They consist of interconnected neurons and glial cells, which provide structural and metabolic support. Neuronal pools are collections of nerve cells with similar functions and interact through chemical and electrical signals. These pools include both interneurons (the central neural circuit nodes that... https://www.jove.com/v/14900 85 2025-06-13T16:07:11+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16094.jpg Feedback control systems Feedback control systems are categorized in various ways based on their design, analysis, and signal types. Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity... https://www.jove.com/v/16094 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16107.jpg Multi-input and Multi-variable systems Cruise control systems in cars are designed as multi-input systems to maintain a driver's desired speed while compensating for external disturbances such as changes in terrain. The block diagram for a cruise control system typically includes two main inputs: the desired speed set by the driver and any external disturbances, such as the incline of the road. By adjusting the engine throttle, the system maintains the vehicle's speed as close to the desired value as possible. In the absence of... https://www.jove.com/v/16107 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16124.jpg Root Loci for Positive-Feedback Systems The Hartley oscillator is a positive feedback system that sustains oscillations by feeding the output back to the input in phase, thereby reinforcing the signal. Positive feedback systems can be viewed as negative feedback systems with inverted feedback signals. In these systems, the root locus encompasses all points on the s-plane where the angle of the system transfer function equals 360 degrees. The construction rules for the root locus in positive feedback systems are similar to those in... https://www.jove.com/v/16124 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52341.jpg Closed-loop Neuro-robotic Experiments to Test Computational Properties of Neuronal Networks In this paper, an experimental framework to perform closed-loop experiments is presented, in which information processing (i.e., coding and decoding) and learning of neuronal assemblies are studied during the continuous interaction with a robotic body. https://www.jove.com/v/52341 678 2015-03-02T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65554.jpg End-To-End Deep Neural Network for Salient Object Detection in Complex Environments The present protocol describes a novel end-to-end salient object detection algorithm. It leverages deep neural networks to enhance the precision of salient object detection within intricate environmental contexts. https://www.jove.com/v/65554 211 2023-12-15T21:10:00+00:00 JoVE no https://visualize.jove.com/17633724-insight-into-efficient-image-registration-techniques-and-the-demons-algorithm monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/59857.jpg Four-Dimensional CT Analysis Using Sequential 3D-3D Registration We analyzed joint kinematics from four-dimensional computed tomography data. The sequential 3D-3D registration method semiautomatically provides the kinematics of the moving bone with respect to the subject bone from four-dimensional computed tomography data. https://www.jove.com/v/59857 305 2019-11-23T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65701.jpg Multimodal Cross-Device and Marker-Free Co-Registration of Preclinical Imaging Modalities The combination of multiple imaging modalities is often necessary to gain a comprehensive understanding of pathophysiology. This approach utilizes phantoms to generate a differential transformation between the coordinate systems of two modalities, which is then applied for co-registration. This method eliminates the need for fiducials in production scans. https://www.jove.com/v/65701 433 2023-10-27T19:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66257.jpg Multi-modal Pulmonary Imaging: Using Complementary Information from CT and Hyperpolarized 129 Xe MRI to Evaluate Lung Structure-Function CT and 129Xe MRI provide complementary lung structure-function information that can be exploited for regional analysis using image registration. Here, we provide a protocol that builds from the existing literature for 129Xe MR to CT image registration using open-source platforms. https://www.jove.com/v/66257 129 2024-04-12T20:20:00+00:00 JoVE no https://visualize.jove.com/17643661-dual-inferior-vena-cava-two-inferior-vena-cava-filters monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15307.jpg Overview of Systemic Arteries The human body is a complex, well-organized machine, and at the heart of its operations lies the circulatory system. This network of blood vessels, which includes systemic arteries, plays a vital role in maintaining life by transporting nutrients, oxygen, and waste products to and from cells throughout the body. Systemic circulation is the part of the cardiovascular system that carries oxygenated blood away from the heart to the body's tissues and returns deoxygenated blood back to the heart. https://www.jove.com/v/15307 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15315.jpg Overview of Systemic Veins Systemic veins are crucial blood vessels that return deoxygenated blood from various body tissues back to the heart. There are three systemic veins that return deoxygenated blood to the heart, they are as follows. The coronary sinus, the heart's principal vein, resides in the coronary sulcus on the heart's posterior aspect. This broad venous channel receives nearly all venous blood from the myocardium, the heart muscle. It is fed by three primary veins: the great cardiac vein, the middle... https://www.jove.com/v/15315 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15316.jpg Veins of Thorax The azygos system is a crucial part of the body's circulatory system and drains most of the thorax. It comprises the azygos, hemiazygos, and accessory hemiazygos veins. The azygos vein, positioned just right of the midline and anterior to the vertebral column, begins at the junction of the right ascending lumbar and subcostal veins, terminating in the superior vena cava. This vein drains blood from the right side of the thoracic wall, thoracic viscera, and posterior abdominal wall. The... https://www.jove.com/v/15316 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15317.jpg Veins of the Abdomen and Pelvis The human body is a complex system of interconnected parts, and the circulatory system plays a crucial role in maintaining overall health. One key component of this system is the inferior vena cava, a large vein responsible for returning blood from the abdominopelvic viscera and abdominal walls to the heart. The inferior vena cava is fed by numerous smaller veins. The lumbar veins, for instance, drain the posterior abdominal wall, emptying both directly into the inferior vena cava and into the... https://www.jove.com/v/15317 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15321.jpg Hepatic Portal System The hepatic portal system, a critical part of our circulatory framework, transports nutrient-laden, deoxygenated blood from the gastrointestinal tract and spleen to the liver. This ingenious system plays an indispensable role in maintaining our body's metabolic equilibrium. At its core, the hepatic portal vein is the result of a confluence of the superior and inferior mesenteric veins along with the splenic vein. Each of these veins has a unique role. The superior mesenteric vein is responsible... https://www.jove.com/v/15321 81 JoVE no https://cloudfront.jove.com/files/ftp_upload/17987/17987_article_thumb_17987.jpg Venous Thrombosis III: Interprofessional Care Venous thrombosis requires effective prevention and treatment strategies to improve patient outcomes and reduce potential complications.Prevention StrategiesHealthcare providers must prioritize preventing venous thromboembolism (VTE) for all adult patients upon admission. Interventions depend on bleeding and thrombosis risk, medical history, current medications, diagnoses, planned procedures, and patient preferences. Patients on bed rest should change positions every two hours and, if not... https://www.jove.com/v/17987 89 2025-06-19T16:20:31+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61215.jpg Three-Dimensional Echocardiographic Method for the Visualization and Assessment of Specific Parameters of the Pulmonary Veins The dimensions of the pulmonary veins (PV) are important parameters when planning pulmonary vein isolation. 2D transoesophageal echocardiography can only provide limited data about the PVs; however, 3D echocardiography can evaluate relevant diameters and areas of the PVs, as well as their spatial relationship to surrounding structures. https://www.jove.com/v/61215 408 2020-10-28T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64790.jpg Image Acquisition Method for the Sonographic Assessment of the Inferior Vena Cava Point-of-care ultrasound evaluation of the inferior vena cava (IVC) is commonly utilized to identify, among other things, the volume status. Imaging should be performed systematically to ensure repeatability. This manuscript reviews the methods and pitfalls of sonographic IVC examination. https://www.jove.com/v/64790 419 2023-01-13T22:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68107.jpg Demystifying Venous Excess Ultrasound (VExUS): Image Acquisition and Interpretation Point-of-care ultrasound (POCUS) is often used to assess the hemodynamic circuit and detect the presence of venous congestion. The Venous Excess Ultrasound (VExUS) scoring system was developed to aid clinicians in predicting the impact of venous congestion on organ dysfunction. This article aims to describe VExUS image acquisition and interpretation. https://www.jove.com/v/68107 349 2025-05-16T21:00:00+00:00 JoVE no https://visualize.jove.com/17645363-core-like-particles-of-an-enveloped-animal-virus-can-self-assemble-efficiently-on-artificial-templates monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3645.jpg Simple and Robust in vivo and in vitro Approach for Studying Virus Assembly A simple, efficient and robust way to synchronize the delivery of multiple viral components to plant cells via Agrobacterium-mediated transient expression is described. This approach is amenable for studying replication, encapsidation followed by in vitro reassembly of non-viral components into genome depleted optical viral ghosts suitable for biomedical applications. https://www.jove.com/v/3645 587 2012-03-01T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10822.jpg Viral Structure Viruses are extraordinarily diverse in shape and size, but they all have several structural features in common. All viruses have a core that contains a DNA- or RNA-based genome. The core is surrounded by a protective coat of proteins called the capsid. The capsid is composed of subunits called capsomeres. The capsid and genome-containing core are together known as the nucleocapsid. Structural Classes of Viruses Many criteria are used to classify viruses, including capsid design. Most viruses... https://www.jove.com/v/10822 56 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11506.jpg Protein Complex Assembly Proteins can form homomeric complexes with another unit of the same protein or heteromeric complexes with different types. Most protein complexes self-assemble spontaneously via ordered pathways, while some proteins need assembly factors that guide their proper assembly. Despite the crowded intracellular environment, proteins usually interact with their correct partners and form functional complexes. Many viruses self-assemble into a fully functional unit using the infected host cell to... https://www.jove.com/v/11506 161 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11506.jpg Protein Complex Assembly Proteins can form homomeric complexes with another unit of the same protein or heteromeric complexes with different types. Most protein complexes self-assemble spontaneously via ordered pathways, while some proteins need assembly factors that guide their proper assembly. Despite the crowded intracellular environment, proteins usually interact with their correct partners and form functional complexes. Many viruses self-assemble into a fully functional unit using the infected host cell to... https://www.jove.com/v/12493 161 JoVE no https://cloudfront.jove.com/files/ftp_upload/19586/19586_article_thumb_19586.jpg Introduction to Virus Viruses are unique biological entities that blur the boundary between living and non-living systems. Although they lack cellular structure and metabolic processes, they can exhibit characteristics of life when infecting a host. Their defining feature is a nucleic acid core, composed of either DNA or RNA, encapsulated within a protein coat called a capsid. This simple structure allows them to invade host cells and use their machinery for replication efficiently.Viral Structure and... https://www.jove.com/v/19586 88 2025-06-12T16:27:43+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19587/19587_article_thumb_19587.jpg Size and Structure of Viral Genomes Viral genomes exhibit remarkable diversity in size, structure, and composition, influencing their replication strategies and interactions with host cells. These genomes consist of either DNA or RNA and may be linear or circular. Additionally, they can be single-stranded or double-stranded, with each configuration affecting how the virus propagates within a host. RNA viruses, for instance, generally have smaller genomes than DNA viruses, a factor that contributes to their high mutation rates and... https://www.jove.com/v/19587 86 2025-06-12T16:27:55+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19592/19592_article_thumb_19592.jpg Viruses with RNA Genomes RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. This classification dictates how they exploit host cellular machinery for protein synthesis and replication. Some RNA viruses also utilize reverse transcription as part of their life cycle, further diversifying their replication strategies.Positive-Strand RNA VirusesPositive-strand RNA viruses have genomes that function directly as messenger... https://www.jove.com/v/19592 89 2025-06-12T16:30:23+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59010.jpg Production of Pseudotyped Particles to Study Highly Pathogenic Coronaviruses in a Biosafety Level 2 Setting Here, we present a protocol to generate pseudotyped particles in a BSL-2 setting incorporating the spike protein of the highly pathogenic viruses Middle East respiratory syndrome and severe acute respiratory syndrome coronaviruses. These pseudotyped particles contain a luciferase reporter gene allowing quantification of virus entry into target host cells. https://www.jove.com/v/59010 520 2019-03-01T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62010.jpg Generation and Assembly of Virus-Specific Nucleocapsids of the Respiratory Syncytial Virus For in-depth mechanistic analysis of the respiratory syncytial virus (RSV) RNA synthesis, we report a protocol of utilizing the chaperone phosphoprotein (P) for coexpression of the RNA-free nucleoprotein (N0) for subsequent in vitro assembly of the virus-specific nucleocapsids (NCs). https://www.jove.com/v/62010 548 2021-07-27T21:00:00+00:00 JoVE no https://visualize.jove.com/17668661-neural-network-adaptive-output-feedback-control-for-intensive-care-unit-sedation-and-intraoperative-anesthesia monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15188.jpg General Anesthesia: Overview Anesthesia is a medical procedure that uses drugs for CNS suppression to enable painless surgeries and procedures. The selection of anesthetics is influenced by their pharmacokinetic properties, side effects, and patient characteristics. Various types of anesthesia include general, local, regional, spinal, and inhalational. General anesthesia induces unconsciousness in the whole body, while the others target specific areas or sensations. It is administered to minimize adverse effects, maintain... https://www.jove.com/v/15188 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15189.jpg Stages of General Anesthesia Various sedation levels offer significant advantages in facilitating procedural interventions for patients undergoing medical or invasive surgical procedures. These levels span from anxiolysis to general anesthesia, providing a spectrum of sedative effects to cater to specific patient needs. Anxiolysis reduces anxiety and is achieved through minimal sedation, enabling patients to remain awake and responsive while feeling more at ease during the procedure. This level can benefit minor... https://www.jove.com/v/15189 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15190.jpg Parenteral Anesthetics: Overview Intravenous anesthetics are drugs administered parenterally to induce anesthesia or sedation. Propofol is a widely used agent formulated as a 1% emulsion in soybean oil, glycerol, and egg phosphatide. It induces rapid anesthesia primarily due to its rapid distribution from the bloodstream to target tissues and is metabolized in the liver. However, it can cause significant pain on injection and hypertriglyceridemia. Fospropofol, a water-based prodrug of propofol, lacks these adverse effects. https://www.jove.com/v/15190 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15706.jpg Neural Control of Respiration The neural regulation of respiration is a meticulously coordinated process primarily controlled by the respiratory centers located within the brainstem. These centers, composed of specialized neurons, transmit nerve impulses that control the contraction and relaxation of our respiratory muscles. Respiratory Centers in the Brainstem Two primary areas comprise the respiratory center: the medullary respiratory center in the medulla oblongata and the pontine respiratory group in the pons. The... https://www.jove.com/v/15706 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16326.jpg Physiology of Respiration II: Neurogenic Control of Respiration The neurogenic control of respiration coordinates various neural networks and pathways to regulate breathing rate and depth, meeting the body's oxygen and carbon dioxide exchange requirements. This system adapts to physiological and environmental conditions, ensuring optimal breathing patterns. Central Control The brainstem is the primary site of central control, hosting respiratory centers: • The Medullary Respiratory Center, comprising the dorsal respiratory group or DRG and the ventral... https://www.jove.com/v/16326 82 JoVE no https://cloudfront.jove.com/files/ftp_upload/17964/17964_article_thumb_17964.jpg Cardiomyopathy VII: Pre and Post Operative Nursing Management Patients with hypertrophic cardiomyopathy (HCM) and left ventricular outflow tract (LVOT) obstruction who remain symptomatic despite optimal medical therapy may undergo a septal myectomy (Morrow procedure). This procedure involves excising a portion of the hypertrophied septum below the aortic valve using a heart-lung machine to improve blood flow through the LVOT. Effective preoperative and postoperative nursing management ensures successful patient outcomes, minimizes complications, and... https://www.jove.com/v/17964 88 2025-06-19T16:43:38+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57919.jpg Intra-Operative Neural Monitoring of Thyroid Surgery in a Porcine Model This study aims to develop a standard protocol of intra-operative neural monitoring of thyroid surgery in a porcine model. Here, we present a protocol to demonstrate general anesthesia, to compare different types of electrodes, and to investigate the electrophysiological characteristics of the normal and injured recurrent laryngeal nerves. https://www.jove.com/v/57919 496 2019-02-11T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61311.jpg Use of an Integrated Low-Flow Anesthetic Vaporizer, Ventilator, and Physiological Monitoring System for Rodents Here, we present a protocol to safely and effectively administer anesthetic gas to mice using a digital, low flow anesthesia system with integrated ventilator and physiological monitoring modules. https://www.jove.com/v/61311 417 2020-07-09T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65235.jpg Non-Intubated Video-Assisted Thoracoscopic Surgery Here, we present a non-intubated protocol for performing video-assisted thoracoscopic surgery with preserved autonomic breathing. https://www.jove.com/v/65235 339 2023-05-26T19:10:00+00:00 JoVE no https://visualize.jove.com/17668673-self-organizing-approximation-based-control-for-higher-order-systems monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16031.jpg Control Systems Control systems are everywhere in contemporary society, influencing diverse applications from aerospace to automated manufacturing. These systems can be found naturally within biological processes, such as blood sugar regulation and heart rate adjustment in response to stress, as well as in man-made systems like elevators and automated vehicles. A control system is essentially a network of subsystems and processes that collaboratively convert specific inputs into desired outputs. At the heart... https://www.jove.com/v/16031 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16094.jpg Feedback control systems Feedback control systems are categorized in various ways based on their design, analysis, and signal types. Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity... https://www.jove.com/v/16094 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16103.jpg Linear Approximation in Time Domain Nonlinear systems often require sophisticated approaches for accurate modeling and analysis, with state-space representation being particularly effective. This method is especially useful for systems where variables and parameters vary with time or operating conditions, such as in a simple pendulum or a translational mechanical system with nonlinear springs. For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length, the... https://www.jove.com/v/16103 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16112.jpg First Order Systems First-order systems, such as RC circuits, are foundational in understanding dynamic systems due to their straightforward input-output relationship. Analyzing their responses to different input functions under zero initial conditions reveals significant insights into system behavior. When a first-order system is subjected to a unit-step input, its response is characterized by its transfer function. By applying the Laplace transform of the unit-step input to the transfer function, expanding the... https://www.jove.com/v/16112 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16113.jpg Second Order systems I A servo system exemplifies a second-order system, featuring a proportional controller and load elements that ensure the output position aligns with the input position. The relationship between these components is described by a second-order differential equation. Applying the Laplace transform under zero initial conditions yields the transfer function, showing how inputs are converted to outputs in the system. By reinterpreting the system, one can derive the closed-loop transfer function, which... https://www.jove.com/v/16113 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16114.jpg Second Order systems II In an underdamped second-order system, where the damping ratio ζ is between 0 and 1, a unit-step input results in a transfer function that, when transformed using the inverse Laplace method, reveals the output response. The output exhibits a damped sinusoidal oscillation, and the difference between the input and output is termed the error signal. This error signal also demonstrates damped oscillatory behavior. Eventually, as the system reaches a steady state, the error diminishes to zero. If ζ... https://www.jove.com/v/16114 78 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61092.jpg WheelCon: A Wheel Control-Based Gaming Platform for Studying Human Sensorimotor Control WheelCon is a novel, free and open-source platform to design video games that noninvasively simulates mountain biking down a steep, twisting, bumpy trail. It contains components presenting in human sensorimotor control (delay, quantization, noise, disturbance, and multiple feedback loops) and allows researchers to study the layered architecture in sensorimotor control. https://www.jove.com/v/61092 498 2020-08-15T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63342.jpg Interactive and Visualized Online Experimentation System for Engineering Education and Research This work describes an online experimentation system that provides visualized experiments, including the visualization of theories, concepts, and formulas, visualizing the experimental process with three-dimensional (3-D) virtual test rigs, and visualizing the control and monitoring system using widgets such as charts and cameras. https://www.jove.com/v/63342 515 2021-11-24T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63575.jpg Design and Application of a Fault Detection Method Based on Adaptive Filters and Rotational Speed Estimation for an Electro-Hydrostatic Actuator In this paper, an adaptive filter based on a normalized least mean square (NLMS) algorithm and a rotational speed estimation method are introduced to detect the electrical and hydraulic faults of the electro-hydrostatic actuator (EHA). The efficacy and feasibility of the aforementioned methods are verified through simulations and experiments. https://www.jove.com/v/63575 405 2022-10-28T20:00:00+00:00 JoVE no https://visualize.jove.com/17668675-characterization-of-analog-local-cluster-neural-network-hardware-for-control monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14900.jpg Neural Circuits Neural circuits and neuronal pools are two of the main structures found in the nervous system. Neural circuits are networks of neurons that work together to carry out a specific task or process. They consist of interconnected neurons and glial cells, which provide structural and metabolic support. Neuronal pools are collections of nerve cells with similar functions and interact through chemical and electrical signals. These pools include both interneurons (the central neural circuit nodes that... https://www.jove.com/v/14900 85 2025-06-13T16:07:11+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16032.jpg Control Systems: Applications Electrical engineering plays a pivotal role in our daily lives, with control systems at the heart of many applications, from home appliances to sophisticated space shuttles. Control systems manage and regulate the behavior of devices and processes, ensuring they function safely, correctly, and efficiently. In modern vehicles, control systems manage various functions to enhance performance and safety. The steering wheel and accelerator are primary inputs in a car's control system. The direction... https://www.jove.com/v/16032 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16092.jpg Open and closed-loop control systems Control systems are foundational elements in automation and engineering. They are broadly categorized into open-loop and closed-loop systems. These classifications hinge on the presence or absence of feedback mechanisms, significantly influencing the system's performance, complexity, and application. An open-loop control system operates without feedback from the output. It consists of two primary elements: the controller and the controlled process. The controller receives an input signal and... https://www.jove.com/v/16092 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16094.jpg Feedback control systems Feedback control systems are categorized in various ways based on their design, analysis, and signal types. Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity... https://www.jove.com/v/16094 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16126.jpg PD Controller: Design In automotive engineering, car suspension systems often employ Proportional Derivative (PD) controllers to enhance performance. PD controllers are utilized to adjust the damping force in response to road conditions. A controller, acting as an amplifier with a constant gain, demonstrates proportional control, with output directly mirroring input. Designing a continuous-data controller requires selecting and linking components like adders and integrators, which are fundamental in Proportional,... https://www.jove.com/v/16126 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16129.jpg PI Controller: Design Proportional Integral (PI) controllers are a fundamental component in modern control systems, widely used to enhance performance and mitigate steady-state errors. They are particularly effective in applications such as automatic brightness adjustment on smartphones, where they excel at mitigating steady-state errors for step-function inputs. Unlike PD controllers, which require time-varying errors to function optimally, PI controllers leverage their integral component to address residual... https://www.jove.com/v/16129 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52341.jpg Closed-loop Neuro-robotic Experiments to Test Computational Properties of Neuronal Networks In this paper, an experimental framework to perform closed-loop experiments is presented, in which information processing (i.e., coding and decoding) and learning of neuronal assemblies are studied during the continuous interaction with a robotic body. https://www.jove.com/v/52341 678 2015-03-02T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58702.jpg Characterization of the Sense of Agency over the Actions of Neural-machine Interface-operated Prostheses Here we present a protocol which characterizes the sense of agency developed over the control of sensate virtual or robotic prosthetic hands. Psychophysical questionnaires are employed to capture the explicit experience of agency, and time interval estimates (intentional binding) are employed to implicitly measure the sense of agency. https://www.jove.com/v/58702 321 2019-01-07T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63205.jpg A Flexible Platform for Monitoring Cerebellum-Dependent Sensory Associative Learning We have developed a single platform to track animal behavior during two climbing fiber-dependent associative learning tasks. The low-cost design allows integration with optogenetic or imaging experiments directed towards climbing fiber-associated cerebellar activity. https://www.jove.com/v/63205 692 2022-01-19T21:00:00+00:00 JoVE no https://visualize.jove.com/17670983-temporal-filtering-of-reward-signals-in-the-dorsal-anterior-cingulate-cortex-during-a-mixed-strategy-game monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17820.jpg Timing and Consequences on Behavior In operant conditioning, the timing of reinforcement is crucial. For animals like rats and cats, immediate reinforcement (within a few seconds) is much more effective than delayed reinforcement. For example, a food reward for a rat needs to follow within 30 seconds of pressing a bar to be effective. Humans, however, can respond to delayed reinforcers. We often make decisions between immediate small rewards and delayed larger rewards. This ability to delay gratification is a significant factor... https://www.jove.com/v/17820 68 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51947.jpg Performing Behavioral Tasks in Subjects with Intracranial Electrodes Patients implanted with intracranial electrodes provide a unique opportunity to record neurological data from multiple areas of the brain while the patient performs behavioral tasks. Here, we present a method of recording from implanted patients that can be reproducible at other institutions with access to this patient population. https://www.jove.com/v/51947 730 2014-10-02T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57907.jpg Operant Protocols for Assessing the Cost-benefit Analysis During Reinforced Decision Making by Rodents A cost-benefit analysis is a weighing-scale approach that the brain performs during the course of decision making. Here, we propose a protocol to train rats on an operant-based decision-making paradigm where rats choose higher rewards at the expense of waiting for 15 s to receive them. https://www.jove.com/v/57907 425 2018-09-10T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64936.jpg The Joint Effect of Social Comparison and Social Distance on Evaluation of Intertemporal Choice Outcomes in Event-related Potential Studies This protocol aims to investigate the neural activity related to social comparison and social distance during the processing of intertemporal decision outcomes. Indifference points will be measured using event-related potentials as part of the study. https://www.jove.com/v/64936 504 2023-08-25T19:30:00+00:00 JoVE no https://visualize.jove.com/17684011-dynamic-integration-of-alpha-adrenergic-and-cholinergic-signals-in-the-atria-role-of-g-protein-regulated-inwardly-rectifying-k-channels monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13323.jpg G-Protein Gated Ion Channels GPCRs are primarily responsible for our sense of smell, taste, and vision. The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response. Sensory organs,... https://www.jove.com/v/13323 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14465.jpg Adrenergic Receptors (Adrenoceptors): Classification Adrenergic receptors, or adrenoceptors, respond to the autonomic neurotransmitter noradrenaline and other endogenous catecholamine agonists. They are classified into two main families, α and β, based on their pharmacological response and are further subdivided depending on their location, elicited response, and affinity to specific agonists or antagonists. α-Adrenoceptors α-Adrenoceptors are classified into two main subtypes: α1 and α2. The α1 adrenoceptors, which are found on postsynaptic... https://www.jove.com/v/14465 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14466.jpg Adrenergic Receptors: ɑ Subtype Adrenoceptors are classified into α and ꞵ classes based on their potencies to catecholamine agonists. α-adrenoceptors show the following order of catecholamine potency: Adrenaline ≥ Noradrenaline >> Isoprenaline α-adrenoceptors are further divided into α1 and α2-adrenoceptors. α1-Adrenoceptors: These receptors are located postsynaptically on the effector organs and cause constriction of smooth muscle mediated by activation of phospholipase C—inositol-1,4,5-trisphosphate... https://www.jove.com/v/14466 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14467.jpg Adrenergic Receptors: β Subtype β-adrenoceptors have varied sensitivities towards adrenaline, noradrenaline, and isoprenaline. The order of agonist potency is as follows: Isoprenaline > Adrenaline > Noradrenaline Neurotransmitter binding to these receptors causes activation of adenylyl cyclase resulting in increased concentrations of cAMP and modulation of calcium ion channels within the cell. They are further classified into β1, β2, and β3 subtypes. β1-adrenoceptors: β1-adrenoceptors have equal affinities for... https://www.jove.com/v/14467 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14951.jpg Sympathetic Signaling Sympathetic signaling, a vital part of the autonomic nervous system, plays a crucial role in mobilizing the body's resources in response to stress or emergencies. It involves the transmission of nerve impulses from sympathetic preganglionic fibers to postganglionic fibers. This results in the release of specific neurotransmitters and activation of adrenergic receptors. Sympathetic preganglionic fibers release the neurotransmitter acetylcholine (ACh) onto the ganglionic neurons in the... https://www.jove.com/v/14951 91 2025-08-12T19:30:45+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14955.jpg Parasympathetic Signaling Parasympathetic signaling plays a crucial role in regulating various physiological processes. It involves the release of acetylcholine (ACh) by parasympathetic neurons, which can have localized and short-lived effects. The majority of ACh released is rapidly inactivated at the synapse by the enzyme acetylcholinesterase (AChE), which hydrolyzes Ach into choline and acetate. Additionally, the tissue cholinesterase deactivates any ACh diffusing into the surrounding tissues. The effects of... https://www.jove.com/v/14955 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50235.jpg Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca 2+ Transients and Membrane Currents We describe the isolation of human atrial myocytes which can be used for intracellular Ca2+ measurements in combination with electrophysiological patch-clamp studies. https://www.jove.com/v/50235 653 2013-07-03T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59588.jpg Isolation of Atrial Myocytes from Adult Mice This protocol is used to isolate single atrial cardiomyocytes from the adult mouse heart using a chunk digestion approach. This approach is used to isolate right or left atrial myocytes that can be used to characterize atrial myocyte electrophysiology in patch-clamp studies. https://www.jove.com/v/59588 514 2019-07-25T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62735.jpg Microelectrode Array Recording of Sinoatrial Node Firing Rate to Identify Intrinsic Cardiac Pacemaking Defects in Mice This protocol aims to describe a new methodology to measure intrinsic cardiac firing rate using microelectrode array recording of the whole sinoatrial node tissue to identify pacemaking defects in mice. Pharmacological agents can also be introduced in this method to study their effects on intrinsic pacemaking. https://www.jove.com/v/62735 560 2021-07-05T22:00:00+00:00 JoVE no https://visualize.jove.com/17688922-comparison-of-two-different-artificial-neural-networks-for-prostate-biopsy-indication-in-two-different-patient-populations monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/50319.jpg Identification of Disease-related Spatial Covariance Patterns using Neuroimaging Data Multivariate techniques including principal component analysis (PCA) have been used to identify signature patterns of regional change in functional brain images. We have developed an algorithm to identify reproducible network biomarkers for the diagnosis of neurodegenerative disorders, assessment of disease progression, and objective evaluation of treatment effects in patient populations. https://www.jove.com/v/50319 867 2013-06-26T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61235.jpg Machine Learning Algorithms for Early Detection of Bone Metastases in an Experimental Rat Model This protocol was designed to train a machine learning algorithm to use a combination of imaging parameters derived from magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) in a rat model of breast cancer bone metastases to detect early metastatic disease and predict subsequent progression to macrometastases. https://www.jove.com/v/61235 435 2020-08-16T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68083.jpg Detection and Isolation of Cancer in Prostate Biopsies Using Stimulated Raman Histology and Artificial Intelligence Here, we present a standardized protocol for detecting prostate cancer using stimulated Raman histology (SRH) on biopsy samples due to advantages over traditional histopathology, focusing on sample preparation, imaging, and artificial intelligence to improve the cancer-to-tissue ratio. Additionally, it supports biobanking for transcriptomics, organoid or xenograft models, and identification of intraoperative surgical margins. https://www.jove.com/v/68083 485 2025-06-10T19:20:00+00:00 JoVE no https://visualize.jove.com/17692405-management-of-the-ascending-aortic-pseudo-aneurysms-a-single-centre-experience monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17903/17903_article_thumb_17903.jpg Aortic Regurgitation I: Introduction IntroductionAortic regurgitation is characterized by the backward flow of blood from the aorta into the left ventricle during diastole and arises from the improper closure of the aortic valve. This condition results in left ventricular volume overload and can stem from both acute and chronic etiologies, each contributing uniquely to the disease's progression and symptomatology.Acute and Chronic CausesAcute aortic regurgitation often results from events that suddenly impair the integrity of the... https://www.jove.com/v/17903 75 2025-06-19T16:20:10+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17905/17905_article_thumb_17905.jpg Aortic Regurgitation III: Medical Management Aortic regurgitation (AR) is when the aortic valve does not close or seal properly, leading to backward blood circulation from the aorta into the left ventricle during diastole. Common causes of AR include rheumatic heart disease, congenital valve defects, and aortic root dilation. Managing AR requires a multifaceted approach to alleviate symptoms, preserve left ventricular function, and address the underlying cause of the regurgitation. Patients with symptomatic AR or significant left... https://www.jove.com/v/17905 85 2025-06-19T16:20:54+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17979/17979_article_thumb_17979.jpg Aneurysm I: Introduction An aortic aneurysm is a localized outpouching or dilation at a weak point in the artery wall. It may involve different parts of the aorta, such as the abdominal aorta, aortic arch, or thoracic aorta.Etiological factorsSeveral disorders are associated with aortic aneurysms.Congenital causes, such as primary connective tissue disorders like Marfan syndrome, impact the integrity and strength of connective tissues, notably affecting the aorta. Marfan syndrome is a genetic disorder that specifically... https://www.jove.com/v/17979 90 2025-06-19T16:19:01+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17980/17980_article_thumb_17980.jpg Aneurysm II: Clinical Manifestations and Diagnostic Studies Thoracic, aortic arch and abdominal aneurysms are significant vascular conditions that can present with various clinical manifestations and lead to serious complications. Understanding these manifestations and the appropriate diagnostic studies is essential for effective management and treatment.Thoracic Aortic AneurysmsThoracic aortic aneurysms often remain asymptomatic until they reach a size that impinges on adjacent structures. They typically cause deep, diffuse chest pain that radiates to... https://www.jove.com/v/17980 81 2025-06-19T16:19:14+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17981/17981_article_thumb_17981.jpg Aneurysm III: Interprofessional Care Aneurysm management involves either conservative medical therapy or surgical intervention, depending on the size and symptoms of the aneurysm. Conservative management is generally reserved for smaller, asymptomatic aneurysms, while larger or symptomatic aneurysms often necessitate surgical repair.Conservative Medical TherapyFor small, asymptomatic aneurysms, particularly abdominal aortic aneurysms (AAA) less than 5.5 centimeters in diameter, conservative medical therapy is recommended. This... https://www.jove.com/v/17981 86 2025-06-19T16:19:25+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17982/17982_article_thumb_17982.jpg Aneurysm IV: Nursing Management Vigilant monitoring for aneurysm rupture is essential for patients undergoing aortic surgery.Preoperative Nursing ManagementContinuously monitor the patient for manifestations of aneurysm rupture, such as pallor, weakness, tachycardia, hypotension, abdominal, back, groin, or periumbilical pain, changes in consciousness, and a pulsating abdominal mass. Regularly assess the patient's peripheral pulses.Instruct the patient to consume a clear liquid diet the day before surgery and administer... https://www.jove.com/v/17982 82 2025-06-19T16:19:35+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63738.jpg Microsurgical Creation of Giant Bifurcation Aneurysms in Rabbits for the Evaluation of Endovascular Devices Here, we describe the technique for the microsurgical creation of giant bifurcation aneurysms in rabbits for the evaluation of endovascular devices. https://www.jove.com/v/63738 441 2023-09-08T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68033.jpg Novel and Innovative Hybrid Technique for Type A Aortic Dissection The protocol describes ascending aortic replacement combined with endovascular coverage of the entire aortic arch with a fenestrated stent graft in a patient with acute type A aortic dissection in the absence of a tear in the aortic arch. https://www.jove.com/v/68033 386 2025-03-28T21:55:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68211.jpg Modified Octopus Technique for Thoracoabdominal Aortic Aneurysm This study describes a modified octopus technique for endovascular treatment of thoracoabdominal aortic aneurysms, demonstrating favorable clinical outcomes. https://www.jove.com/v/68211 296 2025-08-01T19:50:00+00:00 JoVE no https://visualize.jove.com/17699916-facial-action-unit-recognition-by-exploiting-their-dynamic-and-semantic-relationships monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10919.jpg Fixed Action Patterns A fixed action pattern (FAP) is a specific, hard-wired sequence of behaviors that occurs in response to an external stimulus, called a sign stimulus. The behavior is “fixed” because it is essentially unchangeable—proceeding similarly across individuals of a species every time it occurs. Three-Spined Sticklebacks A classic example of a FAP was described in three-spined stickleback fish by Nikolaas Tinbergen in the 1930s. During the breeding season, the male fish develop a red throat and belly... https://www.jove.com/v/10919 66 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14578.jpg Masking and Demasking Agents EDTA titrations may necessitate masking and demasking agents to temporarily protect a particular metal ion in a mixture from the EDTA reaction. These agents facilitate the sequential analysis of the metal ions by forming stable complexes with some—but not all—metal ions during certain steps. There are many masking agents, such as cyanide, fluoride, triethanolamine, thiourea, and 2,3-bis(sulfanyl)propan-1-ol (formerly 2,3-dimercapto-1-propanol), with the masking agent chosen based on the metal... https://www.jove.com/v/14578 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14866.jpg Muscles for Facial Expressions The craniofacial muscles are a collection of approximately 20 thin skeletal muscles situated beneath the skin of the face and scalp. These muscles, primarily responsible for the vast array of human facial expressions, originate from the bones or fibrous structures of the skull and extend outwards to connect with the skin. While most skeletal muscles in the body are enveloped in thick fascia, facial muscles generally have a more delicate fascial covering, with the buccinator muscle being a... https://www.jove.com/v/14866 74 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14908.jpg Association Areas of the Cortex Association areas are regions of the cerebral cortex that do not have a specific sensory or motor function. Instead, they integrate and interpret information from various sources to enable higher cognitive processes such as memory, learning, and decision-making. Some key association areas include the following: Prefrontal Association Area: This area is located in the frontal lobe and is involved in planning, decision-making, and moderating social behavior. It connects with primary motor areas,... https://www.jove.com/v/14908 81 2025-06-13T16:11:09+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18217.jpg Facial Feedback Hypothesis Charles Darwin proposed that facial expressions are an evolutionary adaptation for communication. He argued that these expressions are not influenced by culture but are universal across species. For example, a snarling expression with exposed teeth signals a threat in many animals, including humans. Darwin also suggested that displaying an emotion can intensify the feeling. Smiling, for example, could enhance one's sense of happiness. This idea laid the foundation for understanding the role of... https://www.jove.com/v/18217 84 JoVE no https://cloudfront.jove.com/files/ftp_upload/19923/19923_article_thumb_19923.jpg Automatic Processing and Automatic Social Behavior Automatic processing refers to the cognitive operations that occur without conscious intent or awareness, playing a fundamental role in shaping social cognition and behavior. These processes enable individuals to navigate complex social environments efficiently by relying on mental shortcuts and pre-existing knowledge structures known as schemas. One of the most influential mechanisms underlying automatic processing is priming, which subtly activates mental representations through exposure to... https://www.jove.com/v/19923 88 2025-09-18T17:24:15+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57694.jpg Eye Tracking During Visually Situated Language Comprehension: Flexibility and Limitations in Uncovering Visual Context Effects The present article reviews an eye-tracking methodology for studies on language comprehension. To obtain reliable data, key steps of the protocol must be followed. Among these are the correct set-up of the eye tracker (e.g., ensuring good quality of the eye and head images) and accurate calibration. https://www.jove.com/v/57694 456 2018-11-30T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59827.jpg Dynamic Digital Biomarkers of Motor and Cognitive Function in Parkinson's Disease This protocol offers a digitization of portions of traditional clinical tasks commonly used to measure cognition and motor control in Parkinson’s disease. Clinical tasks are digitized while biophysical rhythms are co-registered from different functional levels of the nervous systems, ranging from voluntary, spontaneous, automatic to autonomic. https://www.jove.com/v/59827 628 2019-07-24T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65931.jpg Artificial Intelligence-Based System for Detecting Attention Levels in Students This paper proposes an artificial intelligence-based system to automatically detect whether students are paying attention to the class or are distracted. This system is designed to help teachers maintain students' attention, optimize their lessons, and dynamically introduce modifications in order for them to be more engaging. https://www.jove.com/v/65931 397 2023-12-15T22:10:00+00:00 JoVE no https://visualize.jove.com/17761880-structural-basis-of-dna-replication-origin-recognition-by-an-orc-protein monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10789.jpg Replication in Eukaryotes Overview In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus. Many Proteins Orchestrate Replication at the Origin Eukaryotic replication follows many of the... https://www.jove.com/v/10789 151 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10789.jpg Replication in Eukaryotes Overview In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus. Many Proteins Orchestrate Replication at the Origin Eukaryotic replication follows many of the... https://www.jove.com/v/11546 151 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11548.jpg The DNA Replication Fork An organism’s genome needs to be duplicated in an efficient and error-free manner for its growth and survival. The replication fork is a Y-shaped active region where two strands of DNA are separated and replicated continuously. The coupling of DNA unzipping and complementary strand synthesis is a characteristic feature of a replication fork. Organisms with small circular DNA, such as E. coli, often have a single origin of replication; therefore, they have only two replication forks, one in... https://www.jove.com/v/11548 62 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11548.jpg The DNA Replication Fork An organism’s genome needs to be duplicated in an efficient and error-free manner for its growth and survival. The replication fork is a Y-shaped active region where two strands of DNA are separated and replicated continuously. The coupling of DNA unzipping and complementary strand synthesis is a characteristic feature of a replication fork. Organisms with small circular DNA, such as E. coli, often have a single origin of replication; therefore, they have only two replication forks, one in... https://www.jove.com/v/13191 62 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13196.jpg Replication in Eukaryotes In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fulfill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus. Many Proteins Orchestrate Replication at the Origin Eukaryotic replication follows many of the same... https://www.jove.com/v/13196 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13196.jpg Replication in Eukaryotes In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fulfill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus. Many Proteins Orchestrate Replication at the Origin Eukaryotic replication follows many of the same... https://www.jove.com/v/13945 89 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57967.jpg Visualizing the Interaction Between the Qdot-labeled Protein and Site-specifically Modified λ DNA at the Single Molecule Level Here, we present a protocol to study DNA-protein interactions by total internal reflection fluorescence microscopy (TIRFM) using a site-specifically modified λ DNA substrate and a Quantum-dot labeled protein. https://www.jove.com/v/57967 536 2018-07-17T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67076.jpg Hybrid Ensemble and Single-molecule Assay to Image the Motion of Fully Reconstituted CMG We report a hybrid ensemble and single-molecule assay to directly image and quantify the motion of fluorescently labeled, fully reconstituted Cdc45/Mcm2-7/GINS (CMG) helicase on linear DNA molecules held in place in an optical trap. https://www.jove.com/v/67076 611 2024-07-26T21:55:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67120.jpg Strand-Specific Analysis of Proteins at Replicating DNA Strands by Enrichment and Sequencing of Protein-Associated Nascent DNA Method Enrichment and sequencing of protein-associated nascent DNA (eSPAN) was developed to detect the relative abundance of a chromatin-associated protein on two replicating DNA strands, thereby revealing molecular insight into chromatin replication and its coupled processes. This protocol describes eSPAN procedures in yeast and mouse embryonic stem (ES) cells. https://www.jove.com/v/67120 533 2025-05-02T19:45:00+00:00 JoVE no https://visualize.jove.com/17873434-an-analytical-comparison-of-the-information-in-sorted-and-non-sorted-cosine-tuned-spike-activity monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2806.jpg Examining Local Network Processing using Multi-contact Laminar Electrode Recording A fundamental issue in our understanding of cortical circuitry is how networks in different cortical layers encode sensory information. Here we describe electrophysiological techniques utilizing multi-contact laminar electrodes to record single-units and local field potentials and present analyses to identify cortical layers. https://www.jove.com/v/2806 820 2011-09-08T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12285.jpg 2D NMR: Homonuclear Correlation Spectroscopy (COSY) Homonuclear correlation spectroscopy, or COSY, is a 2-dimensional NMR technique that provides information about coupled protons. Typically, the geminal and vicinal coupling are observed. For example, consider the COSY spectrum of ethyl acetate, where its 1D proton NMR spectrum is plotted along the vertical and horizontal axes with their corresponding chemical shift scale. Three spots on the diagonal corresponding to the three peaks in the 1D proton spectrum are called diagonal peaks. The COSY... https://www.jove.com/v/12285 66 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14833.jpg 2D NMR: Overview of Homonuclear Correlation Techniques Homonuclear correlation spectroscopy (COSY) is a powerful technique used in Nuclear Magnetic Resonance (NMR) spectroscopy to study the correlations between nuclei of the same type within a molecule. It provides information about scalar couplings between adjacent nuclei, which helps determine connectivity and structural information. There are several COSY variants, each with its unique strengths and experimental parameters. COSY90 is the standard two-dimensional (2D) COSY experiment that... https://www.jove.com/v/14833 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15105.jpg Graphical and Analytic Representation of Sinusoids Analyzing two sinusoidal voltages with equal amplitude and period but different phases on an oscilloscope, an instrument used to display and analyze waveforms, involves a three-step process. The first step is measuring the peak-to-peak value, which is twice the amplitude of the sinusoid. This provides information about the maximum voltage swing of the waveform. Secondly, the period and angular frequency are determined. The period is the time taken for one complete cycle of the waveform, while... https://www.jove.com/v/15105 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55217.jpg A Visual Guide to Sorting Electrophysiological Recordings Using 'SpikeSorter' The article shows how to use the program SpikeSorter to detect and sort spikes in extracellular recordings made with multi-electrode arrays. https://www.jove.com/v/55217 631 2017-02-10T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65245.jpg Multichannel Extracellular Recording in Freely Moving Mice The protocol describes the methodology of extracellular recording in the motor cortex (MC) to reveal extracellular electrophysiological properties in freely moving conscious mice, as well as the data analysis of local field potentials (LFPs) and spikes, which is useful for evaluating the network neural activity underlying behaviors of interest. https://www.jove.com/v/65245 539 2023-05-26T19:20:00+00:00 JoVE no https://visualize.jove.com/17897463-design-and-implementation-of-a-generalized-laboratory-data-model monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14765.jpg Data Validation Method validation is a crucial process in analytical chemistry designed to confirm that a given method consistently produces reliable and high-quality results. This process is essential when a method is applied to different sample matrices or when procedural modifications are made, ensuring that the results meet acceptable standards across various applications. Key parameters for method validation include: Specificity: The ability of the method to accurately measure the target analyte without... https://www.jove.com/v/14765 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16569.jpg Model Approaches for Pharmacokinetic Data: Compartment Models Compartmental analysis is a widely adopted approach to characterizing drug pharmacokinetics. It uses compartment models that conceptualize the body as a collection of reversibly communicating compartments, each representing a group of tissues exhibiting similar drug distribution characteristics. The movement rate of the drug between these compartments is typically described by first-order kinetics. Two primary types of compartment models are recognized: mammillary and catenary. The more... https://www.jove.com/v/16569 74 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16584.jpg Mechanistic Models: Overview of Compartment Models Mechanistic models, a category encompassing both physiological and compartmental modeling, differ from empirical models' approaches to incorporating known factors about the systems being modeled. Empirical models describe data with minimal assumptions, while mechanistic models aim to provide a robust description of available data by specifying assumptions and integrating known factors about the system. Compartmental analysis is a key example of a mechanistic model in pharmacokinetics and... https://www.jove.com/v/16584 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16585.jpg Mechanistic Models: Compartment Models in Individual and Population Analysis Mechanistic models are utilized in individual analysis using single-source data, but imperfections arise due to data collection errors, preventing perfect prediction of observed data. The mathematical equation involves known values (Xi), observed concentrations (Ci), measurement errors (εi), model parameters (ϕj), and the related function (ƒi) for i number of values. Different least-squares metrics quantify differences between predicted and observed values. The ordinary least squares (OLS)... https://www.jove.com/v/16585 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16587.jpg Model Approaches for Pharmacokinetic Data: Physiological Models Physiological models in pharmacokinetics are instrumental in understanding the distribution and elimination of drugs within the body. These models describe the drug concentration within target organs, influenced by factors such as drug uptake, tissue volume, and blood flow. Drug uptake is governed by the partition coefficient, which signifies the drug concentration ratio in tissue to that in the blood. The blood flow rate to a specific tissue is expressed as Qt, and the rate of change in tissue... https://www.jove.com/v/16587 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16591.jpg Model Approaches for Pharmacokinetic Data: Distributed Parameter Models Pharmacokinetic models are mathematical constructs that represent and predict the time course of drug concentrations in the body, providing meaningful pharmacokinetic parameters. These models are categorized into compartment, physiological, and distributed parameter models. The distributed parameter models are specifically designed to account for variations and differences in some drug classes. This model is particularly useful for assessing regional concentrations of anticancer or... https://www.jove.com/v/16591 66 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60038.jpg Databases to Efficiently Manage Medium Sized, Low Velocity, Multidimensional Data in Tissue Engineering Many researchers generate "medium-sized", low-velocity, and multi-dimensional data, which can be managed more efficiently with databases rather than spreadsheets. Here we provide a conceptual overview of databases including visualizing multi-dimensional data, linking tables in relational database structures, mapping semi-automated data pipelines, and using the database to elucidate data meaning. https://www.jove.com/v/60038 583 2019-11-22T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61971.jpg TBase - an Integrated Electronic Health Record and Research Database for Kidney Transplant Recipients TBase combines an electronic health record with an innovative research database for kidney transplant recipients. TBase is built upon an in-memory database platform, connected to different hospital systems, and used for regular outpatient care. It automatically integrates all relevant clinical data including transplantation-specific data creating a unique research database. https://www.jove.com/v/61971 540 2021-04-13T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68448.jpg Efficient Sampling of Genetically Encoded Biosensor Design Space Enabled with a Design of Experiments and Automation Workflow This protocol provides a method for the systematic global optimization of genetically encoded biosensors through automation-assisted genetic library generation and assessment. This is coupled with design-of-experiment methodologies to streamline experimentation and enable the selection of genetic components to tune biosensors to specific design outcomes. https://www.jove.com/v/68448 538 2025-10-17T19:50:00+00:00 JoVE no https://visualize.jove.com/17903470-use-of-sequential-injection-analysis-to-construct-an-electronic-tongue-application-to-multidetermination-employing-the-transient-response-of-a-potentiometric-sensor-array monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4067.jpg Hollow Microneedle-based Sensor for Multiplexed Transdermal Electrochemical Sensing This article details the construction of a multiplexed microneedle-based sensor. The device is being developed for in situ sampling and electrochemical analysis of multiple analytes in a rapid and selective manner. We envision clinical medicine and biomedical research uses for these microneedle-based sensors. https://www.jove.com/v/4067 499 2012-06-01T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14551.jpg Potentiometry: Overview Potentiometry is an analytical technique that measures the potential difference between two electrodes in an electrochemical cell without drawing any significant current that could alter the solution's composition. This method employs an indicator electrode, which exchanges electrons with the analyte solution, and a reference electrode with a constant potential. Each electrode is immersed in a solution comprised of two half-cells. In a conventional setup, the reference electrode serves as the... https://www.jove.com/v/14551 66 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14553.jpg Potentiometry: Membrane Electrodes Membrane electrodes, also known as p-ion electrodes, use membranes that selectively interact with free analyte ions, generating a potential difference across the membrane. The resulting membrane potential, known as the asymmetry potential, is not zero even when analyte concentrations on both sides of the membrane are equal. The membrane's response is typically not selective to a single analyte but proportional to the concentration of all ions in the sample solution capable of interacting at the... https://www.jove.com/v/14553 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14566.jpg Voltammetric Techniques: Linear-Scan (E vs Time) Polarography is a classical voltammetric technique used to analyze electrochemical reactions. This method applies a linear potential sweep to a dropping mercury electrode (DME), and the resulting current is measured. A dropping mercury electrode is commonly used as the working electrode in polarography. It consists of a capillary tube filled with mercury, where the tiny droplet forms at the tip. This droplet continuously drops from the capillary, creating a new electrode surface for each... https://www.jove.com/v/14566 72 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51901.jpg Electronic Tongue Generating Continuous Recognition Patterns for Protein Analysis A novel approach is described for construction of electronic tongue (eT), which greatly simplifies the design and production of sensing materials, and allows the eT to generate continuous evolution profiles and landscapes for samples in liquid. The obtained eT is efficient for common protein analysis such as discrimination. https://www.jove.com/v/51901 526 2014-09-16T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68767.jpg TD-DFT Guided Advanced E-Eye Sensing Technique for On-site Quantification of Fe, Cr, F, and As in the Environmental, Biological, and Food Samples This work has discussed the protocol for designing and developing an E-Eye-Enable POCT device to detect Fe, Cr, As, and F in environmental samples, biological samples, and food and beverages. Nearly 2000 samples have been tested, and the results accord with the gold-standard technique. https://www.jove.com/v/68767 591 2025-09-19T20:50:00+00:00 JoVE no https://visualize.jove.com/17918689-comparison-of-the-levels-of-accuracy-of-an-artificial-neural-network-model-and-a-logistic-regression-model-for-the-diagnosis-of-acute-appendicitis monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17599.jpg Receiver Operating Characteristic Plot A ROC (Receiver Operating Characteristic) plot is a graphical tool used to assess the performance of a binary classification model by illustrating the trade-off between sensitivity (true positive rate) and specificity (false positive rate). By plotting sensitivity against 1 - specificity across various threshold settings, the ROC curve shows how well the model distinguishes between classes, with a curve closer to the top-left corner indicating a more accurate model. The area under the ROC curve... https://www.jove.com/v/17599 75 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58382.jpg Predicting Treatment Response to Image-Guided Therapies Using Machine Learning: An Example for Trans-Arterial Treatment of Hepatocellular Carcinoma Intra-arterial therapies are the standard of care for patients with hepatocellular carcinoma who cannot undergo surgical resection. A method for predicting response to these therapies is proposed. The technique uses pre-procedural clinical, demographic, and imaging information to train machine learning models capable of predicting response prior to treatment. https://www.jove.com/v/58382 249 2018-10-10T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61235.jpg Machine Learning Algorithms for Early Detection of Bone Metastases in an Experimental Rat Model This protocol was designed to train a machine learning algorithm to use a combination of imaging parameters derived from magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) in a rat model of breast cancer bone metastases to detect early metastatic disease and predict subsequent progression to macrometastases. https://www.jove.com/v/61235 435 2020-08-16T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67941.jpg Comparison of Predictive Performance of Three Lymph Node Staging Systems in Colorectal Signet Ring Cell Carcinoma Based on Machine Learning Model This study evaluates prognostic systems for colorectal signet-ring cell carcinoma patients using machine learning models and competing risk analyses. It identifies log odds of positive lymph nodes as a superior predictor compared to pN staging, demonstrating strong predictive performance and aiding clinical decision-making through robust survival prediction tools. https://www.jove.com/v/67941 433 2025-04-18T21:00:00+00:00 JoVE no https://visualize.jove.com/17920439-the-role-of-behavioral-cues-in-understanding-goal-directed-actions-in-infancy monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17736.jpg Behaviorism The field of behaviorism was pioneered by figures such as Ivan Pavlov, John B. Watson, and B.F. Skinner fundamentally shifted the focus of psychology to the observable and controllable aspects of human and animal behavior. This shift marked a critical evolution in the discipline, emphasizing scientific rigor and experimental methodology. The core premise of behaviorism is its focus on observable behavior rather than internal thoughts or feelings. This approach argues that true scientific... https://www.jove.com/v/17736 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17805.jpg Introduction to Learning Learning is the process of acquiring knowledge or skills through practice or experience, leading to long-lasting behavioral changes. This acquisition occurs through interaction with the environment and requires practice or experience. For instance, mastering a skill such as surfing requires considerable practice and experience, highlighting the essential role of repeated interactions with the environment in learning. In contrast to learned behaviors, unlearned behaviors such as crying, sexual... https://www.jove.com/v/17805 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17822.jpg Cognitive Learning Cognitive learning is based on purposive behavior, incidental learning, and insight learning. E. C. Tolman's theory of purposive behavior emphasizes that much behavior is goal-directed. He argued that to understand behavior, we must look at the entire sequence of actions leading to a goal. For instance, high school students study hard, not just due to past reinforcement but also to achieve the goal of getting into a good college. Tolman introduced the idea that behavior is influenced by... https://www.jove.com/v/17822 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17824.jpg Observational Learning Albert Bandura's observational learning, also known as imitation or modeling, occurs when a person observes and imitates another's behavior. It is a quicker process than operant conditioning. A well-known example is the Bobo doll study, where children who saw an adult acting aggressively towards the doll were more likely to act aggressively when left alone, compared to those who observed a nonaggressive adult. Many psychologists view observational learning as a form of latent learning because... https://www.jove.com/v/17824 72 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18554.jpg Piaget's Stage 1 of Cognitive Development The sensorimotor stage, the initial phase of Jean Piaget's theory of cognitive development, spans the first two years of a child's life. During this period, infants actively engage with their surroundings, building cognitive awareness through direct interaction with the world. This interaction is primarily based on sensory perception and motor actions, allowing infants to gradually understand basic physical properties and predict how objects interact within their environment. Exploration... https://www.jove.com/v/18554 74 2025-08-13T20:50:21+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18560.jpg The Nativist Approach The nativist approach to infant cognitive development proposes that infants are born with inherent knowledge structures that allow them to interpret the world almost immediately. This perspective contrasts with earlier developmental theories, such as those proposed by Jean Piaget, which emphasized a more gradual acquisition of cognitive abilities through interaction with the environment. One key concept in this approach is object permanence — the understanding that objects continue to exist... https://www.jove.com/v/18560 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52841.jpg Quantifying Learning in Young Infants: Tracking Leg Actions During a Discovery-learning Task A method is described in which 3-4 month old infants learn a task by discovery and their leg movements are captured to quantify the learning process. https://www.jove.com/v/52841 678 2015-06-01T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53406.jpg A Novel Experimental and Analytical Approach to the Multimodal Neural Decoding of Intent During Social Interaction in Freely-behaving Human Infants This protocol presents a novel methodology for the neural decoding of intent from freely-behaving infants during unscripted social interaction with an actor. Neural activity is acquired using non-invasive high-density active scalp electroencephalography (EEG). Kinematic data is collected with inertial measurement units and supplemented with synchronized video recording. https://www.jove.com/v/53406 674 2015-10-04T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59291.jpg Defining the Role Of Language in Infants' Object Categorization with Eye-tracking Paradigms Here we present a protocol for familiarization-test paradigms which provide a direct test of infant categorization and help to define the role of language in early category learning. https://www.jove.com/v/59291 451 2019-02-08T23:00:00+00:00 JoVE no https://visualize.jove.com/17931630-hydrolysis-of-non-cognate-aminoacyl-adenylates-by-a-class-ii-aminoacyl-trna-synthetase-lacking-an-editing-domain monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11591.jpg Transfer RNA Synthesis One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases. Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with... https://www.jove.com/v/11591 156 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11595.jpg tRNA Activation Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the... https://www.jove.com/v/11595 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11597.jpg Improving Translational Accuracy Base complementarity between the three base pairs of mRNA codon and the tRNA anticodon is not a failsafe mechanism. Inaccuracies can range from a single mismatch to no correct base pairing at all. The free energy difference between the correct and nearly correct base pairs can be as small as 3 kcal/ mol. With complementarity being the only proofreading step, the estimated error frequency would be one wrong amino acid in every 100 amino acids incorporated. However, error frequencies observed in... https://www.jove.com/v/11597 127 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11623.jpg RNA Editing RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or modification. The extent of RNA editing varies from a few hundred bases, in mitochondrial DNA of trypanosomes, to a just single base, in nuclear genes of mammals. Even a single base change in the pre-mRNA can convert a codon for one amino acid into the codon for another amino acid or a stop codon. This type of re-coding can significantly affect the... https://www.jove.com/v/11623 143 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11591.jpg Transfer RNA Synthesis One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases. Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with... https://www.jove.com/v/12569 156 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11595.jpg tRNA Activation Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the... https://www.jove.com/v/13132 146 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51712.jpg RNA Catalyst as a Reporter for Screening Drugs against RNA Editing in Trypanosomes A highly sensitive ribozyme-based assay, applicable to high-throughput screening of chemicals targeting the unique process of RNA editing in trypanosomatid pathogens, is described in this paper. Inhibitors can be used as tools for hypothesis-driven analysis of the RNA editing process and ultimately as therapeutics. https://www.jove.com/v/51712 559 2014-07-22T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54273.jpg Residue-specific Incorporation of Noncanonical Amino Acids into Model Proteins Using an Escherichia coli Cell-free Transcription-translation System An easy-to-use, cell-free expression protocol for the residue-specific incorporation of noncanonical amino acid analogs into proteins, including downstream analysis, is presented for medical, pharmaceutic, structural and functional studies. https://www.jove.com/v/54273 707 2016-08-01T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55638.jpg Protein-tRNA Agarose Gel Retardation Assays for the Analysis of the N 6 -threonylcarbamoyladenosine TcdA Function A protocol is presented for the production of tRNA(UUU) and the analysis of tRNA(UUU) in complex with the enzyme TcdA by agarose gel retardation assays. https://www.jove.com/v/55638 483 2017-06-21T19:30:00+00:00 JoVE no https://visualize.jove.com/17945746-artificial-neural-network-prediction-using-accelerometers-to-control-upper-limb-fes-during-reaching-and-grasping-following-stroke monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/52968.jpg A Structured Rehabilitation Protocol for Improved Multifunctional Prosthetic Control: A Case Study As prosthetic development moves towards the goal of natural control, harnessing amputees’ inherent ability to learn new motor skills may enable proficiency. This manuscript describes a structured rehabilitation protocol, which includes imitation, repetition, and reinforcement learning strategies, for improved multifunctional prosthetic control. https://www.jove.com/v/52968 418 2015-11-07T00:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66938.jpg Enhancing Upper Limb Function and Motor Skills Post-Stroke Through an Upper Limb Rehabilitation Robot This protocol describes an upper limb rehabilitation robot that provides intelligent feedback through four modes. These modes enhance upper limb function and flexibility, thereby improving patients' quality of life. https://www.jove.com/v/66938 289 2024-09-06T20:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68588.jpg Soft Pneumatic Robot Modulates Graph Theory Metrics of Brain Network for Hand Rehabilitation After Stroke This study explores the effects of a configurable soft pneumatic robot on enhancing whole-brain network topology post-stroke. Graph theory analysis indicates significant improvements in clustering coefficient, path length, and global efficiency. Findings highlight the potential of programmable robotic protocols to modulate neuroplasticity and optimize functional recovery in stroke rehabilitation. https://www.jove.com/v/68588 330 2025-10-10T21:40:00+00:00 JoVE no https://visualize.jove.com/17946553-efficient-event-driven-simulation-of-excitable-hybrid-automata monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12415.jpg Woodward–Hoffmann Selection Rules and Microscopic Reversibility Electrocyclic reactions, cycloadditions, and sigmatropic rearrangements are concerted pericyclic reactions that proceed via a cyclic transition state. These reactions are stereospecific and regioselective. The stereochemistry of the products depends on the symmetry characteristics of the interacting orbitals and the reaction conditions. Accordingly, pericyclic reactions are classified as either symmetry-allowed or symmetry-forbidden. Woodward and Hoffmann presented the selection criteria for... https://www.jove.com/v/12415 94 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13681.jpg Cyclic Processes And Isolated Systems A thermodynamic system with zero heat exchange and work is an isolated system. For these systems, the internal energy remains constant. In the case of a non-isolated system, the change in the internal energy is zero only if the process is cyclic. A thermodynamic process is considered cyclic if the system undergoes a series of changes and returns to its initial state. Consider a cyclic process that returns to its initial state, undergoing a four-step process. The heat transfer along each path... https://www.jove.com/v/13681 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16169.jpg Simplified Synchronous Machine Model The Synchronous Machine Model is a fundamental tool in analyzing and ensuring the transient stability of power systems. This model simplifies the representation of a synchronous machine under balanced three-phase positive-sequence conditions, assuming constant excitation and ignoring losses and saturation. The model is pivotal for understanding the behavior of synchronous generators connected to a power grid, particularly during transient events. In this model, each generator is connected to a... https://www.jove.com/v/16169 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16170.jpg Multimachine Stability Multimachine stability analysis is crucial for understanding the dynamics and stability of power systems with multiple synchronous machines. The objective is to solve the swing equations for a network of M machines connected to an N-bus power system. In analyzing the system, the nodal equations represent the relationship between bus voltages, machine voltages, and machine currents. The nodal equation is given by: V is the N-vector of bus voltages, E is the M-vector of machine voltages, I is... https://www.jove.com/v/16170 85 JoVE no https://cloudfront.jove.com/files/ftp_upload/40598/40598_article_thumb_40598_TN.jpg Modeling with Differential Equations Population dynamics can be described mathematically by considering the population size P(t) as a function of time. The rate of change of the population is then represented by the derivative of P(t). A simple assumption is that the rate of growth is proportional to the size of the population itself. This leads to an exponential growth model, where the population increases rapidly without bound. While this is a useful first approximation, it does not reflect realistic long-term... https://www.jove.com/v/40598 85 2026-01-12T20:24:36+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52320.jpg Real-time Electrophysiology: Using Closed-loop Protocols to Probe Neuronal Dynamics and Beyond Closed-loop protocols are becoming increasingly widespread in modern day electrophysiology. We present a simple, versatile and inexpensive way to perform complex electrophysiological protocols in cortical pyramidal neurons in vitro, using a desktop computer and a digital acquisition board. https://www.jove.com/v/52320 488 2015-06-24T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52341.jpg Closed-loop Neuro-robotic Experiments to Test Computational Properties of Neuronal Networks In this paper, an experimental framework to perform closed-loop experiments is presented, in which information processing (i.e., coding and decoding) and learning of neuronal assemblies are studied during the continuous interaction with a robotic body. https://www.jove.com/v/52341 678 2015-03-02T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63575.jpg Design and Application of a Fault Detection Method Based on Adaptive Filters and Rotational Speed Estimation for an Electro-Hydrostatic Actuator In this paper, an adaptive filter based on a normalized least mean square (NLMS) algorithm and a rotational speed estimation method are introduced to detect the electrical and hydraulic faults of the electro-hydrostatic actuator (EHA). The efficacy and feasibility of the aforementioned methods are verified through simulations and experiments. https://www.jove.com/v/63575 405 2022-10-28T20:00:00+00:00 JoVE no https://visualize.jove.com/17946832-association-between-short-term-and-long-term-communication-in-pathological-autonomic-control monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2502.jpg Quantitative Autonomic Testing Standardized, comprehensive and fully quantitative testing of autonomic functions is described. The autonomic tests consist of evaluation of all three major autonomic domains including cardiovagal, adrenergic and sudomotor. The severity and distribution of dysautonomia is quantitated using Composite Autonomic Severity Scores. https://www.jove.com/v/2502 700 2011-07-19T22:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10835.jpg Neural Regulation Digestion begins with a cephalic phase that prepares the digestive system to receive food. When our brain processes visual or olfactory information about food, it triggers impulses in the cranial nerves innervating the salivary glands and stomach to prepare for food. The cephalic phase is a conditioned or learned response to familiar foods. Our appetite or desire for a particular food modifies the preparatory responses directed by the brain. Individuals may produce more saliva and stomach... https://www.jove.com/v/10835 97 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14440.jpg Autonomic Nervous System: Overview The human nervous system is divided into two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS is composed of the brain and spinal cord, while the PNS contains nerve cells, clusters of nerve cells, and the sensory receptors that are outside the CNS. The PNS has two types of nerve cells: sensory (afferent) and motor (efferent). Sensory cells send signals to the CNS from receptors, and motor cells carry signals from the CNS to organs, muscles, and... https://www.jove.com/v/14440 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14442.jpg Classification of Neurotransmitters Neurotransmitters play a crucial role in the communication between neurons in the autonomic nervous system. Neurons in the autonomic nervous system can be cholinergic or adrenergic depending on the neurotransmitters synthesized. Cholinergic neurons use acetylcholine as their primary neurotransmitter. This includes all the preganglionic fibers of the sympathetic and pre- and postganglionic fibers of the parasympathetic nervous systems. In addition, neurons of the somatic nervous system also use... https://www.jove.com/v/14442 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14947.jpg Autonomic Nervous System The autonomic nervous system (ANS) is a critical component of the peripheral nervous system, primarily responsible for regulating involuntary bodily functions and maintaining homeostasis. It functions in tandem with the central nervous system (CNS) to seamlessly coordinate various physiological processes without the need for conscious control. The ANS comprises two main divisions: the sympathetic and parasympathetic divisions. These divisions function antagonistically to maintain a dynamic... https://www.jove.com/v/14947 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14951.jpg Sympathetic Signaling Sympathetic signaling, a vital part of the autonomic nervous system, plays a crucial role in mobilizing the body's resources in response to stress or emergencies. It involves the transmission of nerve impulses from sympathetic preganglionic fibers to postganglionic fibers. This results in the release of specific neurotransmitters and activation of adrenergic receptors. Sympathetic preganglionic fibers release the neurotransmitter acetylcholine (ACh) onto the ganglionic neurons in the... https://www.jove.com/v/14951 91 2025-08-12T19:30:45+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14959.jpg Disorders of the Autonomic Nervous System The autonomic nervous system (ANS) is an intricate network of nerves that controls functions such as the regulation of heart rate, digestion, and blood pressure regulation. When this system malfunctions, it can lead to various disorders that affect multiple bodily functions. One common feature of many autonomic disorders is the involvement of smooth blood vessels, which play a crucial role in regulating blood flow throughout the body. Raynaud's disease, also known as Raynaud's phenomenon, is a... https://www.jove.com/v/14959 78 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61943.jpg Real-Time Proxy-Control of Re-Parameterized Peripheral Signals using a Close-Loop Interface We present protocols and methods of analyses to build co-adaptive interfaces that stream, parameterize, analyze, and modify human body and heart signals in close-loop. This setup interfaces signals derived from the peripheral and central nervous systems of the person with external sensory inputs to help track biophysical change. https://www.jove.com/v/61943 714 2021-05-08T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68016.jpg Studying the Coding Profiles of Somatic Stimulation on Cardiac-locked Neuronal Responses in the Rat Spinal Dorsal Horn We describe a protocol for spinal multichannel extracellular recording alongside cardiac function recording and analyzing the cardiac-locked spinal dorsal horn neurons. This method offers a temporally synchronized framework for studying spinal mechanisms underlying thoracic visceral functional changes induced by acupuncture. https://www.jove.com/v/68016 432 2025-05-23T20:40:00+00:00 JoVE no https://visualize.jove.com/17949482-assisted-reproductive-technology-affects-developmental-kinetics-h19-imprinting-control-region-methylation-and-h19-gene-expression-in-individual-mouse-embryos monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10813.jpg In-vitro Mutagenesis To learn more about the function of a gene, researchers can observe what happens when the gene is inactivated or “knocked out,” by creating genetically engineered knockout animals. Knockout mice have been particularly useful as models for human diseases such as cancer, Parkinson’s disease, and diabetes. The Process Genes can be randomly knocked out, or specific genes can be targeted. To knock out a particular gene, an engineered piece of DNA called a targeting vector is used to replace the... https://www.jove.com/v/10813 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11619.jpg Genomic Imprinting and Inheritance Diploid organisms inherit genetic material through chromosomes from both parents. Copies of the same gene are known as alleles. In most cases, both alleles are simultaneously expressed and allow various cellular processes to function optimally. If one of the alleles is missing or mutated, the expression of the other allele can compensate; however, this is not true for all genes. The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as... https://www.jove.com/v/11619 150 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57442.jpg Using Mouse Oocytes to Assess Human Gene Function During Meiosis I As the genetic variants associated with human disease begin to become uncovered, it is becoming increasingly important to develop systems with which to rapidly evaluate the biological significance of those identified variants. This protocol describes methods for evaluating human gene function during female meiosis I using mouse oocytes. https://www.jove.com/v/57442 673 2018-04-10T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61999.jpg Application of Mouse Parthenogenetic Haploid Embryonic Stem Cells as a Substitute of Sperm This article aims to demonstrate the use of parthenogenetic haploid embryonic stem cells as a substitute for sperm for the construction of semi-cloned embryos. https://www.jove.com/v/61999 488 2020-11-19T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65898.jpg Mouse Round Spermatid Injection Here, we introduce a method for performing round spermatid injection (ROSI) in mice, a technique with promising clinical applications and utility for investigating the mechanisms underlying embryonic development. https://www.jove.com/v/65898 521 2024-01-26T21:50:00+00:00 JoVE no https://visualize.jove.com/17967811-a-statistically-harmonized-alignment-classification-in-image-space-enables-accurate-and-robust-alignment-of-noisy-images-in-single-particle-analysis monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2574.jpg Single Particle Electron Microscopy Reconstruction of the Exosome Complex Using the Random Conical Tilt Method This article describes a standard method to get a three-dimensional (3D) reconstruction of biological macromolecules using negative staining electron microscopy (EM). In this protocol, we explain how to get the 3D structure of the Saccharomyces cerevisiae exosome complex at medium resolution using the random conical tilt reconstruction method (RCT). https://www.jove.com/v/2574 730 2011-03-28T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57690.jpg Multi-color Localization Microscopy of Single Membrane Proteins in Organelles of Live Mammalian Cells Here, we present a protocol for multi-color localization of single membrane proteins in organelles of live cells. To attach fluorophores, self-labeling proteins are used. Proteins, located in different membranes compartments of the same organelle, can be localized with a precision of ~18 nm. https://www.jove.com/v/57690 666 2018-06-30T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62261.jpg Cryo-EM and Single-Particle Analysis with Scipion Single-particle analysis in cryo-electron microscopy is one of the main techniques used to determine the structure of biological ensembles at high resolution. Scipion provides the tools to create the whole pipeline to process the information acquired by the microscope and achieve a 3D reconstruction of the biological specimen. https://www.jove.com/v/62261 546 2021-05-29T20:00:00+00:00 JoVE no https://visualize.jove.com/18082601-variability-and-robustness-in-biomolecular-systems monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/10964/10964_article_thumb_10964.jpg Mutation, Gene Flow, and Genetic Drift In a population that is not at Hardy-Weinberg equilibrium, the frequency of alleles changes over time. Therefore, any deviations from the five conditions of Hardy-Weinberg equilibrium can alter the genetic variation of a given population. Conditions that change the genetic variability of a population include mutations, natural selection, non-random mating, gene flow, and genetic drift (small population size).Mechanisms of Genetic VariationThe original sources of genetic variation are mutations,... https://www.jove.com/v/10964 69 2026-06-01T13:28:07+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11484.jpg Gene Evolution - Fast or Slow? The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain crucial regulatory sequences, the vast majority of this DNA serves no known function. Typically, these regions of the genome are the ones in which the fastest change, in evolutionary terms, is observed, because there is typically little to no selection pressure acting on these regions to preserve their sequences. In contrast, regions which code... https://www.jove.com/v/11484 125 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11522.jpg Protein Complexes with Interchangeable Parts Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct. The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to... https://www.jove.com/v/11522 117 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11522.jpg Protein Complexes with Interchangeable Parts Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct. The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to... https://www.jove.com/v/12504 117 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16478.jpg Variability: Analysis Measures of variability are statistical metrics that reveal the dispersion pattern within a dataset. They are pivotal in biostatistics, providing insights into the heterogeneity within health and biological data. Variability signifies the degree to which data points diverge from one another, helping researchers understand the potential range of values and associated uncertainty within the data. The range is a simple measure of variability, indicating the difference between the highest and... https://www.jove.com/v/16478 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17758.jpg Genetic Variation Genetic variation is the diversity in DNA sequences found among individuals of the same species. This diversity is crucial for a species' survival because it helps organisms adapt to environmental changes. Genetic variation begins with fertilization, where an egg and sperm cell merge. Each of these cells carries 23 chromosomes, up to 46 in the fertilized egg. Chromosomes are long DNA strands that contain genes, the basic units of heredity. Genes exist in different versions called alleles, which... https://www.jove.com/v/17758 85 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55219.jpg Single-cell Gene Expression Profiling Using FACS and qPCR with Internal Standards We describe a method to sort single mammalian cells and to quantify the expression of up to 96 target genes of interest in each cell. This method includes the use of internal qPCR standards to enable the estimation of absolute transcript counts. https://www.jove.com/v/55219 650 2017-02-25T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59438.jpg Robust Comparison of Protein Levels Across Tissues and Throughout Development Using Standardized Quantitative Western Blotting This method describes a robust and reproducible approach for the comparison of protein levels in different tissues and at different developmental timepoints using a standardized quantitative western blotting approach. https://www.jove.com/v/59438 493 2019-04-09T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64709.jpg Following the Dynamics of Structural Variants in Experimentally Evolved Populations We developed a cost-effective method to follow non-single nucleotide polymorphism allele dynamics that can easily be adapted to experimental evolution frozen archives. A triplet PCR technique was coupled with automated parallel capillary electrophoresis to quantify the relative frequency of an insertion allele over the course of experimental evolution. https://www.jove.com/v/64709 292 2023-02-03T21:35:00+00:00 JoVE no https://visualize.jove.com/18093905-spontaneous-fluctuations-in-posterior-alpha-band-eeg-activity-reflect-variability-in-excitability-of-human-visual-areas monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14942.jpg Brain Waves Brain waves are electrical signals generated by the neurons in the brain, which are regularly monitored to measure mental activities. Brain waves and their frequency ranges can be measured using an electroencephalogram or EEG. There are four main types of brain waves, each with distinct characteristics: • Alpha Waves – Alpha brain waves, between 8 and 13 Hz ( Hertz), occur when a person is relaxed with eyes closed. The alpha waves then disappear when one is concentrating on specific tasks. <br... https://www.jove.com/v/14942 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50131.jpg Applications of EEG Neuroimaging Data: Event-related Potentials, Spectral Power, and Multiscale Entropy Neuroimaging researchers typically consider the brain's response as the mean activity across repeated experimental trials and disregard signal variability over time as "noise". However, it is becoming clear that there is signal in that noise. This article describes the novel method of multiscale entropy for quantifying brain signal variability in the time domain. https://www.jove.com/v/50131 675 2013-06-27T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53727.jpg A Multimodal Imaging- and Stimulation-based Method of Evaluating Connectivity-related Brain Excitability in Patients with Epilepsy Resting-state functional-connectivity MRI has identified abnormalities in patients with a wide range of neuropsychiatric disorders, including epilepsy due to malformations of cortical development. Transcranial Magnetic Stimulation in combination with EEG can demonstrate that patients with epilepsy have cortical hyperexcitability in regions with abnormal connectivity. https://www.jove.com/v/53727 503 2016-11-13T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60120.jpg Detecting Pre-Stimulus Source-Level Effects on Object Perception with Magnetoencephalography This article describes how to set up an experiment that allows detecting pre-stimulus source-level influences on object perception using magnetoencephalography (MEG). It covers stimulus material, experimental design, MEG recording, and data analysis. https://www.jove.com/v/60120 565 2019-07-26T22:00:00+00:00 JoVE no https://visualize.jove.com/18214451-auditory-contact-cues-improve-performance-when-grasping-augmented-and-virtual-objects-with-a-tool monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17771.jpg Auditory Perception The auditory system is essential for sound perception, utilizing various critical structures. When sound waves enter the outer ear, they travel through the ear canal and cause the eardrum to vibrate. These vibrations are then transmitted to the middle ear, where three tiny bones – the malleus, incus, and stapes – amplify the sound. This amplification is crucial, as it ensures that the sound vibrations are strong enough to be conveyed to the inner ear. These vibrations then reach the cochlea, a... https://www.jove.com/v/17771 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17772.jpg Perceiving Loudness, Pitch, and Location The human brain perceives pitch through two primary mechanisms reflected in place theory and frequency theory. Each mechanism describes how sound waves are interpreted as specific pitches by the brain, offering insights into the intricate processes of auditory perception. Place theory, or place coding, suggests that different pitches are heard because various sound waves activate specific locations along the cochlea's basilar membrane. The brain determines the pitch of a sound by identifying... https://www.jove.com/v/17772 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55965.jpg Using Virtual Reality to Transfer Motor Skill Knowledge from One Hand to Another We describe a novel virtual-reality based setup which exploits voluntary control of one hand to improve motor-skill performance in the other (non-trained) hand. This is achieved by providing real-time movement-based sensory feedback as if the non-trained hand is moving. This new approach may be used to enhance rehabilitation of patients with unilateral hemiparesis. https://www.jove.com/v/55965 312 2017-09-18T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59493.jpg Applying Incongruent Visual-Tactile Stimuli during Object Transfer with Vibro-Tactile Feedback We present a protocol to apply incongruent visual-tactile stimuli during an object transfer task. Specifically, during block transfers, performed while the hand is hidden, a virtual presentation of the block shows random occurrences of false block drops. The protocol also describes adding vibrotactile feedback while performing the motor task. https://www.jove.com/v/59493 343 2019-05-23T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64877.jpg Estimation of Contact Regions Between Hands and Objects During Human Multi-Digit Grasping When we grasp an object, multiple regions of the fingers and hand typically make contact with the object's surface. Reconstructing such contact regions is challenging. Here, we present a method for approximately estimating the contact regions by combining marker-based motion capture with existing deep learning-based hand mesh reconstruction. https://www.jove.com/v/64877 581 2023-04-21T21:00:00+00:00 JoVE no https://visualize.jove.com/18244055-artificial-intelligence-in-medical-consultation-systems-a-review monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12979.jpg Issues And Trends In Healthcare Delivery System The issues and trends in healthcare delivery are constantly changing. The COVID-19 pandemic is one recent issue that wreaked havoc on healthcare systems, causing a shortage of healthcare workers, high demand for medicines and supplies, and increased medical expenditure due to a lack of insurance. Other issues include rising healthcare costs and care fragmentation. Cost Containment Payment for healthcare services has historically promoted adoption of costly and often unnecessary or inefficient... https://www.jove.com/v/12979 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14125.jpg Health Information Technology and Healthcare Information System Health Information Technology (HIT) Health Information Technology, commonly called HIT, integrates advanced information systems and technology in healthcare settings. Its primary functions include: Documentation and Monitoring of Patient Care: HIT systems facilitate the efficient recording and tracking of patient data, aiding healthcare providers in monitoring patients' health status and making informed decisions. Managerial and Organizational Functions: Beyond patient care, HIT is... https://www.jove.com/v/14125 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66796.jpg Augmenting Large Language Models via Vector Embeddings to Improve Domain-Specific Responsiveness In this protocol, foundation large language model response quality is improved via augmentation with peer-reviewed, domain-specific scientific articles through a vector embedding mechanism. Additionally, code is provided to aid in performance comparison across large language models. https://www.jove.com/v/66796 194 2024-12-06T20:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68270.jpg Introduction of an Integrated Pathology Image Management, Artificial Intelligence, and Reporting System Integrated image management, artificial intelligence (AI), and reporting systems have revolutionized diagnostic pathology practice. In this paper, we introduce FlexLIS, a state-of-the-art system that enables AI to assist pathologists in performing histopathology image assessments and generating diagnostic reports. https://www.jove.com/v/68270 333 2025-07-11T22:40:00+00:00 JoVE no https://visualize.jove.com/18244469-competitive-learning-with-floating-gate-circuits monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13804.jpg Current Growth And Decay In RL Circuits The current growth and decay in RL circuits can be understood by considering a series RL circuit consisting of a resistor, an inductor, a constant source of emf, and two switches. When the first switch is closed, the circuit is equivalent to a single-loop circuit consisting of a resistor and an inductor connected to a source of emf. In this case, the source of emf produces a current in the circuit. If there were no self-inductance in the circuit, the current would rise immediately to a steady... https://www.jove.com/v/13804 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14095.jpg Comparison between RL and RC circuits An RC circuit consists of resistance and capacitance, while in an RL circuit, capacitance is replaced by an inductor. RL and RC circuits are first-order differential circuits that store energy. An RC circuit stores energy in the electric field, while an RL circuit stores energy in the magnetic field. When connected to a battery, an RC circuit charges the capacitor, causing the current to decrease from maximum to zero upon being fully charged. This increases the voltage across the capacitor from... https://www.jove.com/v/14095 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15097.jpg Second-Order Circuits Integrating two fundamental energy storage elements in electrical circuits results in second-order circuits, encompassing RLC circuits and circuits with dual capacitors or inductors (RC and RL circuits). Second-order circuits are identified by second-order differential equations that link input and output signals. Input signals typically originate from voltage or current sources, with the output often representing voltage across the capacitor and/or current through the inductor. For example, in... https://www.jove.com/v/15097 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15137.jpg Network Function of a Circuit Frequency response analysis in electrical circuits provides vital insights into a circuit's behavior as the frequency of the input signal changes. The transfer function, a mathematical tool, is instrumental in understanding this behavior. It defines the relationship between phasor output and input and comes in four types: voltage gain, current gain, transfer impedance, and transfer admittance. The critical components of the transfer function are the poles and zeros. Here, zeros are roots of... https://www.jove.com/v/15137 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15732.jpg Biasing of FET Biasing a Junction Field Effect Transistor (JFET) is crucial for setting operational parameters and ensuring efficient functioning in electronic circuits. JFETs are characterized by using a single carrier type in N-channel or P-channel configurations, where the channel is surrounded by PN junctions. These junctions are central to the device's ability to control current flow. In an N-channel JFET, the structure consists of N-type material forming the channel on a P-type substrate, with the gate... https://www.jove.com/v/15732 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15734.jpg MOSFET: Enhancement Mode Enhancement-mode MOSFETs are pivotal components in electronics, distinguished by their capacity to act as highly efficient switches. They are part of the larger family of metal-oxide Semiconductor Field-Effect Transistors (MOSFETs). They are available in two types: p-channel and n-channel, each tailored to specific polarity operations. In their basic form, enhancement-mode MOSFETs are typically non-conductive when the gate-source voltage (Vgs) is zero. This default 'off' state means no current... https://www.jove.com/v/15734 82 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50581.jpg Nanofabrication of Gate-defined GaAs/AlGaAs Lateral Quantum Dots This paper presents a detailed fabrication protocol for gate-defined semiconductor lateral quantum dots on gallium arsenide heterostructures. These nanoscale devices are used to trap few electrons for use as quantum bits in quantum information processing or for other mesoscopic experiments such as coherent conductance measurements. https://www.jove.com/v/50581 947 2013-11-02T02:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52852.jpg Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping The fabrication process and experimental characterization techniques relevant to single-electron pumps based on silicon metal-oxide-semiconductor quantum dots are discussed. https://www.jove.com/v/52852 898 2015-06-03T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64539.jpg Gene Digital Circuits Based on CRISPR-Cas Systems and Anti-CRISPR Proteins CRISPR-Cas systems and anti-CRISPR proteins were integrated into the scheme of Boolean gates in Saccharomyces cerevisiae. The new small logic circuits showed good performance and deepened the understanding of both dCas9/dCas12a-based transcription factors and the properties of anti-CRISPR proteins. https://www.jove.com/v/64539 646 2022-10-18T22:00:00+00:00 JoVE no https://visualize.jove.com/18249744-design-of-neural-networks-for-fast-convergence-and-accuracy-dynamics-and-control monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16031.jpg Control Systems Control systems are everywhere in contemporary society, influencing diverse applications from aerospace to automated manufacturing. These systems can be found naturally within biological processes, such as blood sugar regulation and heart rate adjustment in response to stress, as well as in man-made systems like elevators and automated vehicles. A control system is essentially a network of subsystems and processes that collaboratively convert specific inputs into desired outputs. At the heart... https://www.jove.com/v/16031 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16094.jpg Feedback control systems Feedback control systems are categorized in various ways based on their design, analysis, and signal types. Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity... https://www.jove.com/v/16094 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16111.jpg Transient and Steady-state Response In control systems, test signals are essential for evaluating performance under various conditions. The ramp function is effective for systems undergoing gradual changes, while the step function is suitable for assessing systems facing sudden disturbances. For systems subjected to shock inputs, the impulse function is the most appropriate test signal. These test signals are integral in designing control systems to exhibit two key performance aspects: transient response and steady-state response. https://www.jove.com/v/16111 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16125.jpg Controller Configurations Controller configurations are crucial in a car's cruise control system because they manage speed over time to maintain a consistent pace regardless of road conditions, thereby meeting design goals. In traditional control systems, fixed-configuration design involves predetermined controller placement. System performance modifications are known as compensation. Control-system compensation involves various configurations, most commonly series or cascade compensation, in which the controller aligns... https://www.jove.com/v/16125 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16126.jpg PD Controller: Design In automotive engineering, car suspension systems often employ Proportional Derivative (PD) controllers to enhance performance. PD controllers are utilized to adjust the damping force in response to road conditions. A controller, acting as an amplifier with a constant gain, demonstrates proportional control, with output directly mirroring input. Designing a continuous-data controller requires selecting and linking components like adders and integrators, which are fundamental in Proportional,... https://www.jove.com/v/16126 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16127.jpg Time-Domain Interpretation of PD Control Proportional-Derivative (PD) control is a widely used control method in various engineering systems to enhance stability and performance. In a system with only proportional control, common issues include high maximum overshoot and oscillation, observed in both the error signal and its rate of change. This behavior can be divided into three distinct phases: initial overshoot, subsequent undershoot, and gradual stabilization. Consider the example of control of motor torque. Initially, a positive... https://www.jove.com/v/16127 67 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50519.jpg Designing and Implementing Nervous System Simulations on LEGO Robots An approach to neural network modeling on the LEGO Mindstorms robotics platform is presented. The method provides a simulation tool for invertebrate neuroscience research in both the research lab and the classroom. This technique enables the investigation of biomimetic robot control principles. https://www.jove.com/v/50519 634 2013-05-25T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52341.jpg Closed-loop Neuro-robotic Experiments to Test Computational Properties of Neuronal Networks In this paper, an experimental framework to perform closed-loop experiments is presented, in which information processing (i.e., coding and decoding) and learning of neuronal assemblies are studied during the continuous interaction with a robotic body. https://www.jove.com/v/52341 678 2015-03-02T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61943.jpg Real-Time Proxy-Control of Re-Parameterized Peripheral Signals using a Close-Loop Interface We present protocols and methods of analyses to build co-adaptive interfaces that stream, parameterize, analyze, and modify human body and heart signals in close-loop. This setup interfaces signals derived from the peripheral and central nervous systems of the person with external sensory inputs to help track biophysical change. https://www.jove.com/v/61943 714 2021-05-08T21:30:00+00:00 JoVE no https://visualize.jove.com/18249769-nonlinear-adaptive-control-using-networks-of-piecewise-linear-approximators monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16094.jpg Feedback control systems Feedback control systems are categorized in various ways based on their design, analysis, and signal types. Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity... https://www.jove.com/v/16094 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16099.jpg Linear Approximation in Frequency Domain Linear systems are characterized by two main properties: superposition and homogeneity. Superposition allows the response to multiple inputs to be the sum of the responses to each individual input. Homogeneity ensures that scaling an input by a scalar results in the response being scaled by the same scalar. In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear. https://www.jove.com/v/16099 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16103.jpg Linear Approximation in Time Domain Nonlinear systems often require sophisticated approaches for accurate modeling and analysis, with state-space representation being particularly effective. This method is especially useful for systems where variables and parameters vary with time or operating conditions, such as in a simple pendulum or a translational mechanical system with nonlinear springs. For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length, the... https://www.jove.com/v/16103 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16126.jpg PD Controller: Design In automotive engineering, car suspension systems often employ Proportional Derivative (PD) controllers to enhance performance. PD controllers are utilized to adjust the damping force in response to road conditions. A controller, acting as an amplifier with a constant gain, demonstrates proportional control, with output directly mirroring input. Designing a continuous-data controller requires selecting and linking components like adders and integrators, which are fundamental in Proportional,... https://www.jove.com/v/16126 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16129.jpg PI Controller: Design Proportional Integral (PI) controllers are a fundamental component in modern control systems, widely used to enhance performance and mitigate steady-state errors. They are particularly effective in applications such as automatic brightness adjustment on smartphones, where they excel at mitigating steady-state errors for step-function inputs. Unlike PD controllers, which require time-varying errors to function optimally, PI controllers leverage their integral component to address residual... https://www.jove.com/v/16129 84 JoVE no https://cloudfront.jove.com/files/ftp_upload/19809/19809_article_thumb_19809_TN.jpg Linearization and Approximation Linearization is a mathematical technique used to approximate complex, nonlinear functions with simpler linear models in the vicinity of a chosen reference point. The method is based on the idea that, although a function may be difficult to evaluate exactly, its behavior near a specific input value can often be closely approximated by the tangent line at that point. This approach is particularly useful when small deviations from a known value are involved.Consider the square root function, for... https://www.jove.com/v/19809 86 2026-01-12T20:24:20+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61092.jpg WheelCon: A Wheel Control-Based Gaming Platform for Studying Human Sensorimotor Control WheelCon is a novel, free and open-source platform to design video games that noninvasively simulates mountain biking down a steep, twisting, bumpy trail. It contains components presenting in human sensorimotor control (delay, quantization, noise, disturbance, and multiple feedback loops) and allows researchers to study the layered architecture in sensorimotor control. https://www.jove.com/v/61092 498 2020-08-15T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61943.jpg Real-Time Proxy-Control of Re-Parameterized Peripheral Signals using a Close-Loop Interface We present protocols and methods of analyses to build co-adaptive interfaces that stream, parameterize, analyze, and modify human body and heart signals in close-loop. This setup interfaces signals derived from the peripheral and central nervous systems of the person with external sensory inputs to help track biophysical change. https://www.jove.com/v/61943 714 2021-05-08T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63575.jpg Design and Application of a Fault Detection Method Based on Adaptive Filters and Rotational Speed Estimation for an Electro-Hydrostatic Actuator In this paper, an adaptive filter based on a normalized least mean square (NLMS) algorithm and a rotational speed estimation method are introduced to detect the electrical and hydraulic faults of the electro-hydrostatic actuator (EHA). The efficacy and feasibility of the aforementioned methods are verified through simulations and experiments. https://www.jove.com/v/63575 405 2022-10-28T20:00:00+00:00 JoVE no https://visualize.jove.com/18249970-an-algorithmic-approach-to-adaptive-state-filtering-using-recurrent-neural-networks monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16100.jpg State Space Representation The frequency-domain technique, commonly used in analyzing and designing feedback control systems, is effective for linear, time-invariant systems. However, it falls short when dealing with nonlinear, time-varying, and multiple-input multiple-output systems. The time-domain or state-space approach addresses these limitations by utilizing state variables to construct simultaneous, first-order differential equations, known as state equations, for an nth-order system. Consider an RLC circuit, a... https://www.jove.com/v/16100 87 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63575.jpg Design and Application of a Fault Detection Method Based on Adaptive Filters and Rotational Speed Estimation for an Electro-Hydrostatic Actuator In this paper, an adaptive filter based on a normalized least mean square (NLMS) algorithm and a rotational speed estimation method are introduced to detect the electrical and hydraulic faults of the electro-hydrostatic actuator (EHA). The efficacy and feasibility of the aforementioned methods are verified through simulations and experiments. https://www.jove.com/v/63575 405 2022-10-28T20:00:00+00:00 JoVE no https://visualize.jove.com/18252429-a-discrete-dynamics-model-for-synchronization-of-pulse-coupled-oscillators monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12764.jpg Oscillations about an Equilibrium Position Stability is an important concept in oscillation. If an equilibrium point is stable, a slight disturbance of an object that is initially at the stable equilibrium point will cause the object to oscillate around that point. For an unstable equilibrium point, if the object is disturbed slightly, it will not return to the equilibrium point. There are three conditions for equilibrium points—stable, unstable, and half-stable. A half-stable equilibrium point is also unstable, but is named so because... https://www.jove.com/v/12764 64 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12769.jpg Damped Oscillations In the real world, oscillations seldom follow true simple harmonic motion. A system that continues its motion indefinitely without losing its amplitude is termed undamped. However, friction of some sort usually dampens the motion, so it fades away or needs more force to continue. For example, a guitar string stops oscillating a few seconds after being plucked. Similarly, one must continually push a swing to keep a child swinging on a playground. Although friction and other non-conservative... https://www.jove.com/v/12769 67 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12771.jpg Forced Oscillations When an oscillator is forced with a periodic driving force, the motion may seem chaotic. The motions of such oscillators are known as transients. After the transients die out, the oscillator reaches a steady state, where the motion is periodic, and the displacement is determined. Using the equations of force and motion, the amplitude of the driven oscillator is obtained. It depends on the natural and driving frequency. In the equation for amplitude, when the driving frequency is much smaller... https://www.jove.com/v/12771 66 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13806.jpg Oscillations In An LC Circuit An idealized LC circuit of zero resistance can oscillate without any source of emf by shifting the energy stored in the circuit between the electric and magnetic fields. In such an LC circuit, if the capacitor contains a charge q before the switch is closed, then all the energy of the circuit is initially stored in the electric field of the capacitor. This energy is given by When the switch is closed, the capacitor begins to discharge, producing a current in the circuit. The current, in turn,... https://www.jove.com/v/13806 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14209.jpg RLC Circuit as a Damped Oscillator An RLC circuit combines a resistor, inductor, and capacitor, connected in a series or parallel combination. Consider a series RLC circuit. Here, the presence of resistance in the circuit leads to energy loss due to joule heating in the resistance. Therefore, the total electromagnetic energy in the circuit is no longer constant and decreases with time. Since the magnitude of charge, current, and potential difference continuously decreases, their oscillations are said to be damped. This is... https://www.jove.com/v/14209 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16053.jpg BIBO stability of continuous and discrete -time systems System stability is a fundamental concept in signal processing, often assessed using convolution. For a system to be considered bounded-input bounded-output (BIBO) stable, any bounded input signal must produce a bounded output signal. A bounded input signal is one where the modulus does not exceed a certain constant at any point in time. To determine the BIBO stability, the convolution integral is utilized when a bounded continuous-time input is applied to a Linear Time-Invariant (LTI) system. https://www.jove.com/v/16053 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51497.jpg Fabrication and Testing of Microfluidic Optomechanical Oscillators Parametric optomechanical excitations have recently been experimentally demonstrated in microfluidic optomechanical resonators by means of optical radiation pressure and stimulated Brillouin scattering. This paper describes the fabrication of these microfluidic resonators along with methodologies for generating and verifying optomechanical oscillations. https://www.jove.com/v/51497 550 2014-05-29T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58240.jpg Reconstitution of Cell-cycle Oscillations in Microemulsions of Cell-free Xenopus Egg Extracts We present a method for the generation of in vitro self-sustained mitotic oscillations at the single-cell level by encapsulating egg extracts of Xenopus laevis in water-in-oil microemulsions. https://www.jove.com/v/58240 391 2018-09-27T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61473.jpg Contribution of the Na + /K + Pump to Rhythmic Bursting, Explored with Modeling and Dynamic Clamp Analyses Presented here is a method for investigation of the roles of the Na+/K+ pump and persistent Na+ current in leech heart interneurons using dynamic clamp. https://www.jove.com/v/61473 514 2021-05-09T20:00:00+00:00 JoVE no https://visualize.jove.com/18255776-noisy-recurrent-neural-networks-the-continuous-time-case monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10835.jpg Neural Regulation Digestion begins with a cephalic phase that prepares the digestive system to receive food. When our brain processes visual or olfactory information about food, it triggers impulses in the cranial nerves innervating the salivary glands and stomach to prepare for food. The cephalic phase is a conditioned or learned response to familiar foods. Our appetite or desire for a particular food modifies the preparatory responses directed by the brain. Individuals may produce more saliva and stomach... https://www.jove.com/v/10835 97 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14900.jpg Neural Circuits Neural circuits and neuronal pools are two of the main structures found in the nervous system. Neural circuits are networks of neurons that work together to carry out a specific task or process. They consist of interconnected neurons and glial cells, which provide structural and metabolic support. Neuronal pools are collections of nerve cells with similar functions and interact through chemical and electrical signals. These pools include both interneurons (the central neural circuit nodes that... https://www.jove.com/v/14900 85 2025-06-13T16:07:11+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16040.jpg Basic Continuous Time Signals Basic continuous-time signals include the unit step function, unit impulse function, and unit ramp function, collectively referred to as singularity functions. Singularity functions are characterized by discontinuities or discontinuous derivatives. The unit step function, denoted u(t), is zero for negative time values and one for positive time values, exhibiting a discontinuity at t=0. This function often represents abrupt changes, such as the step voltage introduced when turning a car's... https://www.jove.com/v/16040 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16046.jpg Classification of Systems-II Continuous-time systems have continuous input and output signals, with time measured continuously. These systems are generally defined by differential or algebraic equations. For instance, in an RC circuit, the relationship between input and output voltage is expressed through a differential equation derived from Ohm's law and the capacitor relation, Discrete-time systems have input and output signals at specific intervals, defined at distinct instants by difference equations. An example is a... https://www.jove.com/v/16046 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16066.jpg Continuous -time Fourier Transform The Fourier series is instrumental in representing periodic functions, offering a powerful method to decompose such functions into a sum of sinusoids. This technique, however, necessitates modification when applied to nonperiodic functions. Consider a pulse-train waveform consisting of a series of rectangular pulses. When these pulses have a finite period, they can be accurately represented by a Fourier series. Yet, as the period approaches infinity, resulting in a single, isolated pulse, the... https://www.jove.com/v/16066 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16077.jpg Sampling Continuous Time Signal In signal processing, a continuous-time signal can be sampled using an impulse-train sampling technique, followed by the zero-order hold method. Impulse-train sampling involves the use of a periodic impulse train, which consists of a series of delta functions spaced at regular intervals determined by the sampling period. When a continuous-time signal is multiplied by this impulse train, it generates impulses with amplitudes corresponding to the signal's values at the sampling points. In the... https://www.jove.com/v/16077 71 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52341.jpg Closed-loop Neuro-robotic Experiments to Test Computational Properties of Neuronal Networks In this paper, an experimental framework to perform closed-loop experiments is presented, in which information processing (i.e., coding and decoding) and learning of neuronal assemblies are studied during the continuous interaction with a robotic body. https://www.jove.com/v/52341 678 2015-03-02T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61290.jpg Continuous Measurement of Biological Noise in Escherichia Coli Using Time-lapse Microscopy This work presents a microscopy method that allows live imaging of a single cell of Escherichia coli for analysis and quantification of the stochastic behavior of synthetic gene circuits. https://www.jove.com/v/61290 505 2021-04-27T19:30:00+00:00 JoVE no https://visualize.jove.com/18255894-orthogonal-schemes-for-bidirectional-associative-memories monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3300.jpg T-maze Forced Alternation and Left-right Discrimination Tasks for Assessing Working and Reference Memory in Mice This article presents the protocol of T-maze tests using a modified automated apparatus for assessing the learning and memory functions in mice. https://www.jove.com/v/3300 1065 2012-02-26T22:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12415.jpg Woodward–Hoffmann Selection Rules and Microscopic Reversibility Electrocyclic reactions, cycloadditions, and sigmatropic rearrangements are concerted pericyclic reactions that proceed via a cyclic transition state. These reactions are stereospecific and regioselective. The stereochemistry of the products depends on the symmetry characteristics of the interacting orbitals and the reaction conditions. Accordingly, pericyclic reactions are classified as either symmetry-allowed or symmetry-forbidden. Woodward and Hoffmann presented the selection criteria for... https://www.jove.com/v/12415 94 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17806.jpg Associative Learning Associative learning is a fundamental concept in behavioral psychology, wherein a connection is established between two stimuli or events, leading to a learned response. This process is critical in understanding how behaviors are acquired and modified. Conditioning, the mechanism through which associations are formed, can be divided into two main types: classical conditioning and operant conditioning, each elucidating different aspects of associative learning. Classical conditioning, also known... https://www.jove.com/v/17806 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18168.jpg Understanding Memory Memory is the retention of information or experiences over time, facilitated through three main processes: encoding, storage, and retrieval. Encoding is the process of inputting information into the memory system. For instance, when listening to a lecture, watching a play, reading a book, or having a conversation, the brain is actively encoding information. This initial stage involves transforming sensory input into a form that can be processed and stored by the brain. Various factors, such as... https://www.jove.com/v/18168 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18169.jpg System of Memory Memory is categorized into three major systems: sensory memory, short-term memory (STM), and long-term memory (LTM). These systems differ in their capacity and the duration for which they can hold information. Sensory memory captures raw sensory input from the environment, holding it for just a few seconds or less. For example, on hearing a brief, loud sound, like a car horn honking, the sound seems to linger in the mind for a moment even after it stops. This is an instance of sensory memory... https://www.jove.com/v/18169 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18174.jpg Storage A schema is a mental framework that helps individuals organize and interpret information. Schemata, formed from previous experiences, influence how we process new information: how we encode it, the inferences we make, and how we retrieve it. For instance, a schema for what a typical classroom looks like might include desks, a teacher's desk, a whiteboard, and students in such an environment. This expectation helps us quickly understand and navigate new classrooms without needing to analyze each... https://www.jove.com/v/18174 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18194.jpg Mnemonic Devices Mnemonic devices are cognitive tools that facilitate memory retention by linking new information to familiar patterns or organizational strategies. These techniques are beneficial for remembering complex or lengthy sets of information by simplifying and structuring them in easily retrievable ways. Acronyms Acronyms are created by using the initial letters of a series of words to form a new word or phrase. This approach condenses complex information into a single, memorable entity. For example,... https://www.jove.com/v/18194 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52667.jpg The Double-H Maze: A Robust Behavioral Test for Learning and Memory in Rodents The goal of this protocol is to investigate spatial cognition in rodents. The double-H water maze is a novel test, which is particularly useful to elucidate the different components of learning, consolidation and memory, as well as the interplay of memory systems. https://www.jove.com/v/52667 541 2015-07-08T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66456.jpg An Appetitive Spatial Working Memory Task for Mice in a Semi-Automated 8-Arm Radial Maze, Reducing Fearful Memory Association in the Maze Most behavior experiments for rodents were originally devised for rats. Due to the behavioral differences between rats and mice, sometimes modifications are required for mice. We present a method to test spatial working memory in mice, minimizing the stress during the working memory task. https://www.jove.com/v/66456 864 2025-07-29T19:30:00+00:00 JoVE no https://visualize.jove.com/18255965-universal-stabilization-using-control-lyapunov-functions-adaptive-derivative-feedback-and-neural-network-approximators monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1677.jpg An Experimental Platform to Study the Closed-loop Performance of Brain-machine Interfaces We use a closed-loop fly-machine interface to investigate general principles in neuronal control. https://www.jove.com/v/1677 651 2011-03-10T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16092.jpg Open and closed-loop control systems Control systems are foundational elements in automation and engineering. They are broadly categorized into open-loop and closed-loop systems. These classifications hinge on the presence or absence of feedback mechanisms, significantly influencing the system's performance, complexity, and application. An open-loop control system operates without feedback from the output. It consists of two primary elements: the controller and the controlled process. The controller receives an input signal and... https://www.jove.com/v/16092 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16094.jpg Feedback control systems Feedback control systems are categorized in various ways based on their design, analysis, and signal types. Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity... https://www.jove.com/v/16094 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16099.jpg Linear Approximation in Frequency Domain Linear systems are characterized by two main properties: superposition and homogeneity. Superposition allows the response to multiple inputs to be the sum of the responses to each individual input. Homogeneity ensures that scaling an input by a scalar results in the response being scaled by the same scalar. In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear. https://www.jove.com/v/16099 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16103.jpg Linear Approximation in Time Domain Nonlinear systems often require sophisticated approaches for accurate modeling and analysis, with state-space representation being particularly effective. This method is especially useful for systems where variables and parameters vary with time or operating conditions, such as in a simple pendulum or a translational mechanical system with nonlinear springs. For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length, the... https://www.jove.com/v/16103 81 JoVE no https://cloudfront.jove.com/files/ftp_upload/19809/19809_article_thumb_19809_TN.jpg Linearization and Approximation Linearization is a mathematical technique used to approximate complex, nonlinear functions with simpler linear models in the vicinity of a chosen reference point. The method is based on the idea that, although a function may be difficult to evaluate exactly, its behavior near a specific input value can often be closely approximated by the tangent line at that point. This approach is particularly useful when small deviations from a known value are involved.Consider the square root function, for... https://www.jove.com/v/19809 86 2026-01-12T20:24:20+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19810/19810_article_thumb_19810_TN.jpg Application of Linearization and Approximation A drone flying through complex terrain often relies on more than one sensing method to estimate small changes in altitude. Along with direct measurements, air pressure provides a useful indirect indicator of vertical movement. Atmospheric pressure decreases as altitude increases, and this relationship is commonly described using an exponential model. Although accurate, converting pressure measurements into altitude values requires calculations that are too complex to perform repeatedly during... https://www.jove.com/v/19810 89 2026-01-12T20:24:59+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55431.jpg Gain-compensation Methodology for a Sinusoidal Scan of a Galvanometer Mirror in Proportional-Integral-Differential Control Using Pre-emphasis Techniques We propose a method to extend the corresponding frequency by using a pre-emphasis technique. This method compensates for the gain reduction of a galvanometer mirror in sine-wave path tracking using proportional-integral-differential control. https://www.jove.com/v/55431 541 2017-04-04T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63575.jpg Design and Application of a Fault Detection Method Based on Adaptive Filters and Rotational Speed Estimation for an Electro-Hydrostatic Actuator In this paper, an adaptive filter based on a normalized least mean square (NLMS) algorithm and a rotational speed estimation method are introduced to detect the electrical and hydraulic faults of the electro-hydrostatic actuator (EHA). The efficacy and feasibility of the aforementioned methods are verified through simulations and experiments. https://www.jove.com/v/63575 405 2022-10-28T20:00:00+00:00 JoVE no https://visualize.jove.com/18276356-back-propagation-learning-and-nonidealities-in-analog-neural-network-hardware monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10846.jpg Long-term Potentiation Long-term potentiation, or LTP, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTP is the process of synaptic strengthening that occurs over time between pre- and postsynaptic neuronal connections. The synaptic strengthening of LTP works in opposition to the synaptic weakening of long-term depression (LTD) and together are the main mechanisms that underlie learning and memory. Hebbian LTP LTP can occur when presynaptic... https://www.jove.com/v/10846 95 2025-10-23T18:49:27+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/14894/14894_article_thumb_14894.jpg Propagation of Action Potentials The propagation of an action potential refers to the process by which a nerve impulse, or "action potential," travels along a neuron. Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to... https://www.jove.com/v/14894 83 2025-08-11T22:39:58+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14900.jpg Neural Circuits Neural circuits and neuronal pools are two of the main structures found in the nervous system. Neural circuits are networks of neurons that work together to carry out a specific task or process. They consist of interconnected neurons and glial cells, which provide structural and metabolic support. Neuronal pools are collections of nerve cells with similar functions and interact through chemical and electrical signals. These pools include both interneurons (the central neural circuit nodes that... https://www.jove.com/v/14900 85 2025-06-13T16:07:11+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15077.jpg Characteristics of OpAmp The operational amplifier, commonly known as an op-amp, is a specially designed electronic circuit component. Its purpose is to work in conjunction with other circuit elements to execute a defined signal-processing operation. Consider an equivalent circuit model of an op-amp, as depicted in Figure 1; the output section comprises a voltage-controlled source in parallel with the output resistance Ro. Figure 1: The equivalent circuit of the nonideal op-amp Figure 1 shows that the input resistance... https://www.jove.com/v/15077 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16099.jpg Linear Approximation in Frequency Domain Linear systems are characterized by two main properties: superposition and homogeneity. Superposition allows the response to multiple inputs to be the sum of the responses to each individual input. Homogeneity ensures that scaling an input by a scalar results in the response being scaled by the same scalar. In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear. https://www.jove.com/v/16099 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17745.jpg Neuroplasticity Neuroplasticity reflects the brain's remarkable capacity to adapt and evolve, responding dynamically to learning, experiences, or injury by reorganizing its neural circuitry. This reorganization involves creating new neural connections and refining old ones through a series of biological processes that contribute to the brain's lifelong development and adaptability. • The brain's ability to change begins with the growth of dendrites and axons, which effectively increases the structural... https://www.jove.com/v/17745 61 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52320.jpg Real-time Electrophysiology: Using Closed-loop Protocols to Probe Neuronal Dynamics and Beyond Closed-loop protocols are becoming increasingly widespread in modern day electrophysiology. We present a simple, versatile and inexpensive way to perform complex electrophysiological protocols in cortical pyramidal neurons in vitro, using a desktop computer and a digital acquisition board. https://www.jove.com/v/52320 488 2015-06-24T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52341.jpg Closed-loop Neuro-robotic Experiments to Test Computational Properties of Neuronal Networks In this paper, an experimental framework to perform closed-loop experiments is presented, in which information processing (i.e., coding and decoding) and learning of neuronal assemblies are studied during the continuous interaction with a robotic body. https://www.jove.com/v/52341 678 2015-03-02T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66142.jpg Two-Photon Polymerization 3D-Printing of Micro-scale Neuronal Cell Culture Devices 3D printing at the micrometer scale enables rapid prototyping of polymeric devices for neuronal cell cultures. As a proof-of-principle, structural connections between neurons were constrained by creating barriers and channels influencing neurite outgrowth, while the functional consequences of such manipulation were observed by extracellular electrophysiology. https://www.jove.com/v/66142 458 2024-06-07T20:10:00+00:00 JoVE no https://visualize.jove.com/18276374-vlsi-implementation-of-art1-memories monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15152.jpg Semiconductors There is variation in the electrical conductivity of materials - metals, semiconductors, and insulators that are showcased with the help of the energy band diagrams. Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining... https://www.jove.com/v/15152 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18168.jpg Understanding Memory Memory is the retention of information or experiences over time, facilitated through three main processes: encoding, storage, and retrieval. Encoding is the process of inputting information into the memory system. For instance, when listening to a lecture, watching a play, reading a book, or having a conversation, the brain is actively encoding information. This initial stage involves transforming sensory input into a form that can be processed and stored by the brain. Various factors, such as... https://www.jove.com/v/18168 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18169.jpg System of Memory Memory is categorized into three major systems: sensory memory, short-term memory (STM), and long-term memory (LTM). These systems differ in their capacity and the duration for which they can hold information. Sensory memory captures raw sensory input from the environment, holding it for just a few seconds or less. For example, on hearing a brief, loud sound, like a car horn honking, the sound seems to linger in the mind for a moment even after it stops. This is an instance of sensory memory... https://www.jove.com/v/18169 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18175.jpg Long-Term Memory Long-term memory is a relatively permanent type of memory, capable of storing vast amounts of information over extended periods. Its storage capacity is generally considered unlimited. Long-term memory can be categorized into two primary types: explicit and implicit memory. Explicit memory, also known as declarative memory, involves the conscious recollection of information that we deliberately try to remember, recall, and articulate. This type of memory encompasses specific facts, events, and... https://www.jove.com/v/18175 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18176.jpg Explicit Memories Explicit memories, also known as declarative memories, are consciously remembered, recalled, and reported. Studying for a chemistry exam involves material that will become part of explicit memory. There are two types of explicit memory: episodic and semantic. Episodic memory contains information about personally experienced events and is reported as a story. An example of episodic memory is recalling a birthday celebration. This type of memory includes the what, where, and when of an event, as... https://www.jove.com/v/18176 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18177.jpg Implicit Memories Implicit memories, also known as non-declarative memories, are long-term memories that function outside of conscious awareness. These memories influence behavior and skills without explicit knowledge. This type of memory is evident in tasks like playing tennis, snowboarding, and texting. Implicit memory has three subsystems: procedural memory, conditioning, and priming. This type of memory is essential in various activities, from everyday tasks to specialized skills. One key aspect of implicit... https://www.jove.com/v/18177 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56076.jpg A Method for Growing Bio-memristors from Slime Mold This paper introduces an improved method for growing bio-memristors out of the plasmodium of Physarum polycephalum. Such a method has proven to decrease growth time, increase component lifespan, standardize electrical observations, and create a protected environment that can be integrated into conventional circuitry. https://www.jove.com/v/56076 466 2017-11-02T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58998.jpg Assembly and Characterization of Biomolecular Memristors Consisting of Ion Channel-doped Lipid Membranes Soft, low-power, biomolecular memristors leverage similar composition, structure, and switching mechanisms of bio-synapses. Presented here is a protocol to assemble and characterize biomolecular memristors obtained from insulating lipid bilayers formed between water droplets in oil. The incorporation of voltage-activated alamethicin peptides results in memristive ionic conductance across the membrane. https://www.jove.com/v/58998 487 2019-03-09T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61026.jpg In Situ Transmission Electron Microscopy with Biasing and Fabrication of Asymmetric Crossbars Based on Mixed-Phased a -VO x Presented here is a protocol for analyzing nanostructural changes during in situ biasing with transmission electron microscopy (TEM) for a stacked metal-insulator-metal structure. It has significant applications in resistive switching crossbars for the next generation of programmable logic circuits and neuromimicking hardware, to reveal their underlying operation mechanisms and practical applicability. https://www.jove.com/v/61026 589 2020-05-13T20:00:00+00:00 JoVE no https://visualize.jove.com/18282614-cochlear-implant-and-inner-ear-malformation-proposal-for-an-hyperosmolar-therapy-at-surgery monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/54951.jpg A Comparative Study of Drug Delivery Methods Targeted to the Mouse Inner Ear: Bullostomy Versus Transtympanic Injection Two microsurgery approaches for local drug delivery to the inner ear are described here and compared in terms of impact on hearing parameters, cochlear cytoarchitecture and expression of inflammatory markers. https://www.jove.com/v/54951 558 2017-03-08T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60795.jpg Intrathecal Application of a Fluorescent Dye for the Identification of Cerebrospinal Fluid Leaks in Cochlear Malformation Intrathecally applied fluorescein is used to achieve intraoperative visualization of CSF leaks. This protocol describes a lumbar puncture, the application of 5% fluorescein, and intraoperative visualization using a fully digital microscope. https://www.jove.com/v/60795 419 2020-02-29T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66565.jpg Enhanced Cochlear Coverage and Hearing Preservation in High-Frequency Hearing Loss via Electric Acoustic Stimulation with Longer Electrode Electric acoustic stimulation (EAS) with longer electrodes can offer broader cochlear coverage and various types of maps in cases of high-frequency hearing loss. Combining less invasive surgery, flexible lateral-wall electrodes, and steroid administration permits deeper insertion with little or no surgical trauma, resulting in good preservation of hearing. https://www.jove.com/v/66565 229 2024-10-11T19:40:00+00:00 JoVE no https://visualize.jove.com/18296174-on-2-d-recursive-lms-algorithms-using-arma-prediction-for-adpcm-encoding-of-images monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16047.jpg Linear time-invariant Systems A system is linear if it displays the characteristics of homogeneity and additivity, together termed the superposition property. This principle is fundamental in all linear systems. Linear time-invariant (LTI) systems include systems with linear elements and constant parameters. The input-output behavior of an LTI system can be fully defined by its response to an impulsive excitation at its input. Once this impulse response is known, the system's reaction to any other input can be calculated... https://www.jove.com/v/16047 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16049.jpg Convolution: Math, Graphics, and Discrete Signals In any LTI (Linear Time-Invariant) system, the convolution of two signals is denoted using a convolution operator, assuming all initial conditions are zero. The convolution integral can be divided into two parts: the zero-input or natural response and the zero-state or forced response, with t0 indicating the initial time. To simplify the convolution integral, it is assumed that both the input signal and impulse response are zero for negative time values. The graphical convolution process... https://www.jove.com/v/16049 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16078.jpg Reconstruction of Signal using Interpolation Signal processing techniques are essential for accurately converting continuous signals to digital formats and vice versa. When a continuous signal is sampled with a period T, the resulting sampled signal exhibits replicas of the original spectrum in the frequency domain, spaced at intervals equal to the sampling frequency. To handle this sampled signal, a zero-order hold method can be applied, which creates a piecewise constant signal by retaining each sample's value until the next sampling... https://www.jove.com/v/16078 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16099.jpg Linear Approximation in Frequency Domain Linear systems are characterized by two main properties: superposition and homogeneity. Superposition allows the response to multiple inputs to be the sum of the responses to each individual input. Homogeneity ensures that scaling an input by a scalar results in the response being scaled by the same scalar. In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear. https://www.jove.com/v/16099 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16103.jpg Linear Approximation in Time Domain Nonlinear systems often require sophisticated approaches for accurate modeling and analysis, with state-space representation being particularly effective. This method is especially useful for systems where variables and parameters vary with time or operating conditions, such as in a simple pendulum or a translational mechanical system with nonlinear springs. For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length, the... https://www.jove.com/v/16103 81 JoVE no https://cloudfront.jove.com/files/ftp_upload/40663/40663_article_thumb_40663.png Linear Approximations For a differentiable function of two variables, linear approximation estimates values near a known point by replacing the curved surface with its tangent plane. Consider the function\begin{equation*}f(x,y)=x^2+3y^2\end{equation*}near the point (2, 1). The exact value at this point is f(2, 1) = 22 + 3(1)2 = 4 + 3 = 7.The linear approximation of f(x, y)) near (a, b) is\begin{equation*}L(x,y)=f(a,b)+f_x(a,b)(x-a)+f_y(a,b)(y-b)\end{equation*}First, compute the partial derivatives: fx(x, y) = 2x and... https://www.jove.com/v/40663 83 2026-06-08T16:38:27+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59158.jpg Shaping the Amplitude and Phase of Laser Beams by Using a Phase-only Spatial Light Modulator We show how to encode the complex field of laser beams by using a single phase element. A common-path interferometer is employed to mix the phase information displayed into a phase-only spatial light modulator to finally retrieve the desired complex field pattern at the output of an optical imaging system. https://www.jove.com/v/59158 519 2019-01-28T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63575.jpg Design and Application of a Fault Detection Method Based on Adaptive Filters and Rotational Speed Estimation for an Electro-Hydrostatic Actuator In this paper, an adaptive filter based on a normalized least mean square (NLMS) algorithm and a rotational speed estimation method are introduced to detect the electrical and hydraulic faults of the electro-hydrostatic actuator (EHA). The efficacy and feasibility of the aforementioned methods are verified through simulations and experiments. https://www.jove.com/v/63575 405 2022-10-28T20:00:00+00:00 JoVE no https://visualize.jove.com/18347877-a-model-for-mechano-electrical-feedback-effects-on-atrial-flutter-interval-variability monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3103.jpg High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation This report provides a detailed description of the methodology and results of simultaneous endocardial and epicardial optical mapping of electrical excitation in the intact left atrium of a Langendorff-perfused sheep heart during stretch-induced atrial fibrillation. https://www.jove.com/v/3103 557 2011-07-29T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15027.jpg Electrophysiology of Normal Cardiac Rhythm The normal cardiac rhythm is a synchronized electrical activity that facilitates the regular and coordinated contraction of the heart muscle. This process is essential for efficient blood circulation throughout the body. The fundamental elements involved in establishing and maintaining this rhythm include the unique electrical properties of cardiac muscle cells, the sinoatrial (SA) node's pacemaker function, the specialized conducting system, and the ionic mechanisms underlying each phase of... https://www.jove.com/v/15027 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15028.jpg Mechanism of Cardiac Arrhythmias Arrhythmias are irregular heart rhythms occurring when the heart's electrical impulses become abnormal. These disturbances can lead to various symptoms, depending on their severity and the underlying cause. Some common factors contributing to arrhythmias include hypoxia, ischemia, electrolyte imbalances, excessive catecholamine exposure, drug toxicity, and muscle overstretching. Arrhythmias can be classified into two main types based on the rate and site of origin of abnormal heart rhythms. https://www.jove.com/v/15028 88 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62735.jpg Microelectrode Array Recording of Sinoatrial Node Firing Rate to Identify Intrinsic Cardiac Pacemaking Defects in Mice This protocol aims to describe a new methodology to measure intrinsic cardiac firing rate using microelectrode array recording of the whole sinoatrial node tissue to identify pacemaking defects in mice. Pharmacological agents can also be introduced in this method to study their effects on intrinsic pacemaking. https://www.jove.com/v/62735 560 2021-07-05T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63567.jpg Transesophageal Atrial Burst Pacing for Atrial Fibrillation Induction in Rats The present work describes an experimental protocol of transesophageal atrial burst pacing for efficient induction of atrial fibrillation (AF) in rats. The protocol can be used in rats with healthy or remodeled hearts, allowing the study of AF pathophysiology, identification of novel therapeutic targets, and evaluation of new therapeutic strategies. https://www.jove.com/v/63567 312 2022-02-14T23:00:00+00:00 JoVE no https://visualize.jove.com/18353365-allostery-absence-of-a-change-in-shape-does-not-imply-that-allostery-is-not-at-play monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/837.jpg Paradigms for Pharmacological Characterization of C. elegans Synaptic Transmission Mutants This video demonstrates how to employ two neural stimulants, aldicarb and pentylenetetrazole (PTZ), in complementary ways to study synaptic function in the nematode, C. elegans. This complementary approach may also be used to shed light on evolutionarily conserved mechanisms for modulating neuronal synchrony and has implications for epilepsy and seizures. https://www.jove.com/v/837 1081 2008-08-19T00:08:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/4198.jpg Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles We describe a method to directly measure muscle force, muscle power, contractile kinetics and fatigability of isolated skeletal muscles in an in vitro system using field stimulation. Valuable information on Ca2+ handling properties and contractile machinery of the muscle can be obtained using different stimulating protocols. https://www.jove.com/v/4198 842 2012-11-01T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10974.jpg Allosteric Regulation Allosteric regulation of enzymes occurs when the binding of an effector molecule to a site that is different from the active site causes a change in the enzymatic activity. This alternate site is called an allosteric site, and an enzyme can contain more than one of these sites. Allosteric regulation can either be positive or negative, resulting in an increase or decrease in enzyme activity. Most enzymes that display allosteric regulation are metabolic enzymes involved in the degradation or... https://www.jove.com/v/10974 68 2025-10-23T18:48:33+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10974.jpg Allosteric Regulation Allosteric regulation of enzymes occurs when the binding of an effector molecule to a site that is different from the active site causes a change in the enzymatic activity. This alternate site is called an allosteric site, and an enzyme can contain more than one of these sites. Allosteric regulation can either be positive or negative, resulting in an increase or decrease in enzyme activity. Most enzymes that display allosteric regulation are metabolic enzymes involved in the degradation or... https://www.jove.com/v/11515 68 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11517.jpg Cooperative Allosteric Transitions Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the... https://www.jove.com/v/11517 118 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11517.jpg Cooperative Allosteric Transitions Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the... https://www.jove.com/v/12168 118 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12221.jpg Allosteric Proteins-ATCase Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor. Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,... https://www.jove.com/v/12221 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11517.jpg Cooperative Allosteric Transitions Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the... https://www.jove.com/v/12500 118 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55523.jpg Assessment of Spontaneous Alternation, Novel Object Recognition and Limb Clasping in Transgenic Mouse Models of Amyloid-β and Tau Neuropathology Described here is a staged, behavioral screening approach that can be used to screen for compounds that exhibit in vivo efficacy on cognitive and functional motor behaviors in transgenic mouse models of β-amyloidosis and tauopathy. These methods are optimized to screen compounds for activity in short-term and working memory tasks. https://www.jove.com/v/55523 602 2017-05-28T20:00:00+00:00 JoVE no https://visualize.jove.com/18361230-computer-assisted-systems-for-arthroscopic-reconstruction-of-anterior-cruciate monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/51597.jpg Surgical Retrieval, Isolation and In vitro Expansion of Human Anterior Cruciate Ligament-derived Cells for Tissue Engineering Applications For future applications as a patch to repair partial tears of the Anterior Cruciate Ligament (ACL), human ACL derived cells were isolated from tissue obtained during reconstructive procedures, expanded in vitro and grown on tissue engineered scaffolds. Cellular adhesion and morphology was then performed to confirm biocompatibility on scaffold surface. https://www.jove.com/v/51597 510 2014-04-30T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52797.jpg Athymic Rat Model for Evaluation of Engineered Anterior Cruciate Ligament Grafts Animal models are important tools for the evaluation of tissue-engineered grafts. This paper presents the protocol for preparing an electrospun biodegradable polymer graft for use in anterior cruciate ligament tissue engineering, as well as a surgical protocol for implantation in a rat model. https://www.jove.com/v/52797 632 2015-03-26T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65620.jpg Arthroscopic Excision of Posterior Cruciate Ligament Cysts Using a Double Posteromedial Approach We present a surgical approach to treat posterior cruciate ligament cysts by an arthroscopic double posteromedial approach. https://www.jove.com/v/65620 344 2023-10-20T21:50:00+00:00 JoVE no https://visualize.jove.com/18369991-using-synthetic-precursor-and-inhibitor-mirnas-to-understand-mirna-function monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10801.jpg MicroRNAs MicroRNA (miRNA) are short, regulatory RNA transcribed from introns—non-coding regions of a gene—or intergenic regions—stretches of DNA present between genes. Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA ends... https://www.jove.com/v/10801 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10804.jpg RNA Interference RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated. This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used... https://www.jove.com/v/10804 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10804.jpg RNA Interference RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated. This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used... https://www.jove.com/v/11627 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10801.jpg MicroRNAs MicroRNA (miRNA) are short, regulatory RNA transcribed from introns—non-coding regions of a gene—or intergenic regions—stretches of DNA present between genes. Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA ends... https://www.jove.com/v/11628 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12033.jpg Experimental RNAi RNA interference (RNAi) is a cellular mechanism that inhibits gene expression by suppressing its transcription or activating the RNA degradation process. The mechanism was discovered by Andrew Fire and Craig Mello in 1998 in plants. Today, it is observed in almost all eukaryotes, including protozoa, flies, nematodes, insects, parasites, and mammals. This precise cellular mechanism of gene silencing has been developed into a technique that provides an efficient way to identify and determine the... https://www.jove.com/v/12033 135 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13151.jpg MicroRNAs MicroRNA (miRNA) are short, regulatory RNA transcribed from introns (non-coding regions of a gene) or intergenic regions (stretches of DNA present between genes). Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself, forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA... https://www.jove.com/v/13151 82 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57786.jpg Biotin-based Pulldown Assay to Validate mRNA Targets of Cellular miRNAs This report describes a fast and reliable method for validating mRNA targets of cellular miRNAs. The method uses synthetic biotinylated Locked Nucleic Acid (LNA)-based miRNA mimics to capture target mRNA. Subsequently, streptavidin-coated magnetic beads are employed to pulldown the target mRNA for quantification by qPCR polymerase chain reaction. https://www.jove.com/v/57786 660 2018-06-12T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57845.jpg In Vivo Nanovector Delivery of a Heart-specific MicroRNA-sponge Tissue-specific microRNA inhibition is a technology that is underdeveloped in the microRNA field. Herein, we describe a protocol to successfully inhibit the miR-181 microRNA family in myoblast cells from the heart. Nanovector technology is used to deliver a microRNA sponge that demonstrates significant in vivo cardio-specific miR-181 family inhibition. https://www.jove.com/v/57845 593 2018-06-15T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62430.jpg mirMachine: A One-Stop Shop for Plant miRNA Annotation Herein, we present a new and fully automated miRNA pipeline, mirMachine that 1) can identify known and novel miRNAs more accurately and 2) is fully automated and freely available. Users can now execute a short submission script to run the fully automated mirMachine pipeline. https://www.jove.com/v/62430 376 2021-05-01T20:30:00+00:00 JoVE no https://visualize.jove.com/18373882-clinical-review-critical-care-transport-and-austere-critical-care monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16351.jpg Acute Respiratory Failure-III Hypercapnic respiratory failure, also known as Type 2 or ventilatory respiratory failure, is a severe condition characterized by the body's inability to effectively remove carbon dioxide (CO2) from the bloodstream. It leads to an arterial CO2 pressure (PaCO2) exceeding 45 mmHg and a blood pH above 7.35. This situation indicates that the body's ventilatory demand, or the ventilation needed to maintain normal PaCO2 levels, surpasses its supply or the maximum gas flow achievable without causing... https://www.jove.com/v/16351 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16352.jpg Acute Respiratory Failure-IV Respiratory failure can manifest suddenly or gradually, characterized by a rapid decline in PaO2 and a rapid rise in PaCO2. This situation indicates a severe respiratory problem that may quickly become a life-threatening emergency. One of the early signs of hypoxemic Acute Respiratory Failure (ARF) is a change in mental status due to the brain's sensitivity to oxygen levels and changes in acid-base balance. Symptoms such as restlessness, confusion, and agitation suggest inadequate oxygen... https://www.jove.com/v/16352 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16353.jpg Acute Respiratory Failure-V The treatment for acute respiratory failure varies based on factors like the underlying cause, overall health, and severity. A collaborative healthcare team is essential for early detection, often through arterial blood gas analysis. Identifying the cause is the primary goal, with treatment strategies adjusted for ventilation/perfusion (V/Q) mismatch, shunting, or diffusion impairment. Ensure that patients are monitored continuously for their response to therapy, including changes in... https://www.jove.com/v/16353 89 JoVE no https://cloudfront.jove.com/files/ftp_upload/17931/17931_article_thumb_17931.jpg Acute Coronary Syndrome IV: Interprofessional Care IntroductionThe management of Acute Coronary Syndrome (ACS) aims to minimize myocardial damage, preserve myocardial function, and prevent complications.Initial ManagementInpatient management involves continuous cardiac monitoring, preferably in an ICU, focusing on blood pressure, serum sodium, potassium, and creatinine levels, and urine output. Ongoing pharmacologic management is crucial for stabilizing the patient.Supplemental Oxygen: Administer supplemental oxygen if oxygen saturation is... https://www.jove.com/v/17931 88 2025-06-19T16:29:05+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17932/17932_article_thumb_17932.jpg Acute Coronary Syndrome V: Nursing Management Nursing Assessment:Nursing management of acute coronary syndrome (ACS) involves taking the patient's history, focusing on primary complaints such as chest pain, dyspnea, and excessive sweating (diaphoresis), as well as other symptoms like back or jaw pain, nausea, vomiting, palpitations, dizziness, and fatigue. The nurse also reviews the patient's history of cardiac events, risk factors such as hypertension, diabetes, smoking, family history, and current medications.In the objective assessment,... https://www.jove.com/v/17932 86 2025-06-19T16:29:20+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18479/18479_article_thumb_18479.jpg Continuous Renal Replacement Therapy Continuous Renal Replacement Therapy, also known as CRRT, is a procedural treatment for acute kidney injury (AKI) that gradually removes uremic toxins and fluids while maintaining acid-base balance and stabilizing electrolytes. It is particularly useful for hemodynamically unstable patients. Unlike intermittent hemodialysis, which is faster, CRRT provides a gentler approach over 24 hours, closely mimicking the function of natural kidneys. However, CRRT is not ideal for patients with... https://www.jove.com/v/18479 90 2025-06-19T16:27:33+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58802.jpg Observational Study Protocol for Repeated Clinical Examination and Critical Care Ultrasonography Within the Simple Intensive Care Studies Structured protocols are necessary to provide answers on research questions in critically ill patients. The Simple Intensive Care Studies (SICS) provides an infrastructure for repeated measurements in critically ill patients including clinical examination, biochemical analysis and ultrasonography. SICS projects have specific focus but the structure is flexible to other investigations.<br... https://www.jove.com/v/58802 638 2019-01-16T21:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61644.jpg Halogenated Agent Delivery in Porcine Model of Acute Respiratory Distress Syndrome via an Intensive Care Unit Type Device We describe a model of hydrochloric acid-induced acute respiratory distress syndrome (ARDS) in piglets receiving sedation with halogenated agents, isoflurane and sevoflurane, through a device used for inhaled intensive care sedation. This model can be used to investigate the biological mechanisms of halogenated agents on lung injury and repair. https://www.jove.com/v/61644 576 2020-09-24T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68479.jpg Preoxygenation Techniques for Tracheal Intubation in Critically Ill Adults Utilizing Oxygen Mask and Noninvasive Ventilation We present evidence-based preoxygenation strategies that demonstrate the use of oxygen masks and noninvasive positive pressure ventilation to optimize oxygenation in critically ill patients undergoing emergent tracheal intubation, thereby reducing the risk of hypoxemia, extending safe apnea time, and minimizing complications. https://www.jove.com/v/68479 435 2025-12-05T21:35:00+00:00 JoVE no https://visualize.jove.com/18392128-standardisation-of-reference-intervals-an-australasian-view monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13225.jpg Range Rule of Thumb to Interpret Standard Deviation The range rule of thumb in statistics helps us calculate a dataset's minimum and maximum values with known standard deviation. This rule is based on the concept that 95% of all values in a dataset lie within two standard deviations from the mean. For instance, the range rule of thumb can be used to find the tallest and the shortest student in a class, given the mean student height and standard deviation. If the mean student height is 1.6 m and the standard deviation, s is 0.05 m, the height of... https://www.jove.com/v/13225 73 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13587.jpg Interpretation of Confidence Intervals A confidence interval is a better estimate of the population than a point estimate, as it uses a range of values from a sample instead of a single value. Confidence intervals have confidence coefficients that are crucial for their interpretation. The most common confidence coefficients are 0.90, 0.95, and 0.99, which can be written as percentages–90%, 95%, and 99%, respectively. Suppose a person calculates a confidence interval with a confidence coefficient of 0.95. In that case, they can... https://www.jove.com/v/13587 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14513.jpg Uncertainty: Confidence Intervals The confidence interval is the range of values around the mean that contains the true mean. It is expressed as a probability percentage. The interpretation of a 95% confidence interval, for instance, is that the statistician is 95% confident that the true mean falls within the interval. The upper and lower limits of this range are known as confidence limits. The confidence limits for the true mean are estimated from the sample's mean, the standard deviation, and the statistical factor 't,' or... https://www.jove.com/v/14513 54 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16478.jpg Variability: Analysis Measures of variability are statistical metrics that reveal the dispersion pattern within a dataset. They are pivotal in biostatistics, providing insights into the heterogeneity within health and biological data. Variability signifies the degree to which data points diverge from one another, helping researchers understand the potential range of values and associated uncertainty within the data. The range is a simple measure of variability, indicating the difference between the highest and... https://www.jove.com/v/16478 71 JoVE no https://cloudfront.jove.com/files/ftp_upload/17157/17157_article_thumb_17157.jpg Bioequivalence Data: Statistical Interpretation The statistical interpretation of bioequivalence data is a significant aspect of pharmaceutical research. Bioequivalence refers to the absence of any significant difference in the rate and extent to which the active ingredient in pharmaceutical products becomes available at the site of drug action when administered at the same molar dose under similar conditions. This helps determine if different drug products have similar absorption rates, ensuring their interchangeability.Statistical... https://www.jove.com/v/17157 76 2026-03-02T20:57:38+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17178/17178_article_thumb_17178.jpg Dosage Regimen: Individualization Individualization in dosing regimens is the customization of medication doses for individual patients. Its necessity arises from the goal of maximizing therapeutic benefits while minimizing risks. This approach is pivotal because human responses to drugs can vary widely; what is effective for one person may be inadequate or excessive for another. Interpatient (intersubject) variability refers to differences in drug responses between individuals, while intrapatient (intrasubject) variability... https://www.jove.com/v/17178 84 2025-10-03T14:00:29+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55386.jpg Absolute Quantification of Aβ 1-42 in CSF Using a Mass Spectrometric Reference Measurement Procedure A reference measurement procedure for the absolute quantification of Aβ1-42 in human CSF based on solid-phase extraction and liquid chromatography tandem mass spectrometry is described. https://www.jove.com/v/55386 520 2017-03-21T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63364.jpg Evaluation of a Point-of-Care Testing Analyzer for Measuring Peripheral Blood Leukocytes A protocol to measure peripheral blood leukocytes using a POCT card-based leukocyte analyzer is presented here. Same blood samples were tested by two automated hematology analyzers to evaluate the consistency and accuracy of the results. The results showed that the evaluated analyzer had a good correlation with the reference system. https://www.jove.com/v/63364 358 2022-03-22T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65410.jpg Reproducibility and Harmonization in Research Using Biological Standards: The Example of Platelet Agonist Collagen-Related Peptide Here we present a method to standardize the platelet agonist collagen-related peptide cross-linked (CRP-XL) using light transmission aggregometry. While the protocol is targeted at platelet function, the experimental process can be applied to most biological molecules and bioassays to ensure scientific rigor and reproducibility. https://www.jove.com/v/65410 290 2023-08-04T20:00:00+00:00 JoVE no https://visualize.jove.com/18410383-collective-behavior-in-gene-regulation-post-transcriptional-regulation-and-the-temporal-compartmentalization-of-cellular-cycles monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11606.jpg Regulation of Expression Occurs at Multiple Steps Gene expression can be regulated at almost every step from gene to protein. Transcription is the step that is most commonly regulated. This involves the binding of proteins to short regulatory sequences on the DNA. This association can either promote or inhibit the transcription of a gene associated with the respective sequence. Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a... https://www.jove.com/v/11606 144 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12000.jpg Circadian Rhythms and Gene Regulation The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent years,... https://www.jove.com/v/12000 139 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11606.jpg Regulation of Expression Occurs at Multiple Steps Gene expression can be regulated at almost every step from gene to protein. Transcription is the step that is most commonly regulated. This involves the binding of proteins to short regulatory sequences on the DNA. This association can either promote or inhibit the transcription of a gene associated with the respective sequence. Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a... https://www.jove.com/v/13142 144 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13181.jpg Structure of a Gene A gene is the fundamental unit of heredity. Every individual has two copies of each gene, one inherited from each parent. Although most people contain the same genes, there is a small fraction that is slightly different amongst people. A gene with a small difference in its sequence of DNA bases forms different alleles, contributing to different phenotypes. However, only 1% of the DNA is composed of genes that encode proteins; the rest, 99% is non-coding DNA. This non-coding DNA performs... https://www.jove.com/v/13181 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12000.jpg Circadian Rhythms and Gene Regulation The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent years,... https://www.jove.com/v/13335 139 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13949.jpg Regulation of Expression at Multiple Steps The gene expression in cells is regulated at different stages: (i) transcription, (ii) RNA processing, (iii) RNA localization, and (iv) translation. Transcriptional regulation is mediated by regulatory proteins such as transcription factors, activators, or repressors—these control gene expression by initiating or inhibiting the transcription of genes. Once a precursor or pre-mRNA is produced, it undergoes post-transcriptional modification, including 5' capping, splicing, and the addition of a... https://www.jove.com/v/13949 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55745.jpg Studying Cell Cycle-regulated Gene Expression by Two Complementary Cell Synchronization Protocols We report two cell synchronization protocols that provide a context for studying events related to specific phases of the cell cycle. We show that this approach is useful for analyzing the regulation of specific genes in an unperturbed cell cycle or upon exposure to agents affecting the cell cycle. https://www.jove.com/v/55745 722 2017-06-06T22:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60455.jpg Real-time Bioluminescence Imaging of Notch Signaling Dynamics during Murine Neurogenesis Neural stem/progenitor cells exhibit various expression dynamics of Notch signaling components that lead to different outcomes of cellular events. Such dynamic expression can be revealed by real-time monitoring, not by static analysis, using a highly sensitive bioluminescence imaging system that enables visualization of rapid changes in gene expressions. https://www.jove.com/v/60455 625 2019-12-12T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63084.jpg Inherent Dynamics Visualizer, an Interactive Application for Evaluating and Visualizing Outputs from a Gene Regulatory Network Inference Pipeline The Inherent Dynamics Visualizer is an interactive visualization package that connects to a gene regulatory network inference tool for enhanced, streamlined generation of functional network models. The visualizer can be used to make more informed decisions for parameterizing the inference tool, thus increasing confidence in the resulting models. https://www.jove.com/v/63084 644 2021-12-07T21:30:00+00:00 JoVE no https://visualize.jove.com/18428412-human-artificial-chromosome-assembly-by-transposon-based-retrofitting-of-genomic-bacs-with-synthetic-alpha-satellite-arrays monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/50346.jpg Recombineering Homologous Recombination Constructs in Drosophila Homologous recombination techniques greatly advance Drosophila genetics by enabling the creation of molecularly precise mutations. The recent adoption of recombineering allows one to manipulate large pieces of DNA and transform them into Drosophila6. The methods presented here combine these techniques to rapidly generate large homologous recombination vectors. https://www.jove.com/v/50346 863 2013-07-13T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52155.jpg Subcloning Plus Insertion (SPI) - A Novel Recombineering Method for the Rapid Construction of Gene Targeting Vectors Gene targeting methodologies can be used to generate transgenic mice with knockout, knock-in and tagged alleles. Here, we describe an improved method of recombineering in E. coli, that we term ‘subcloning plus insertion’, which can be used to generate custom gene targeting vectors rapidly. https://www.jove.com/v/52155 542 2015-01-08T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53164.jpg Bacterial Artificial Chromosomes: A Functional Genomics Tool for the Study of Positive-strand RNA Viruses Here, a protocol is presented for creating an infectious bacterial artificial chromosome containing a full-length cDNA of the positive-strand genomic RNA of Japanese encephalitis virus. This protocol can be used to construct a functional cDNA of other positive-strand RNA viruses, making it a powerful genomic tool for studying virus biology. https://www.jove.com/v/53164 740 2015-12-29T21:00:00+00:00 JoVE no https://visualize.jove.com/18463131-visant-an-integrative-framework-for-networks-in-systems-biology monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11525.jpg Protein Networks An organism can have thousands of different proteins, and these proteins must cooperate to ensure the health of an organism. Proteins bind to other proteins and form complexes to carry out their functions. Many proteins interact with multiple other proteins creating a complex network of protein interactions. These interactions can be represented through maps depicting protein-protein interaction networks, represented as nodes and edges. Nodes are circles that are representative of a protein,... https://www.jove.com/v/11525 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11525.jpg Protein Networks An organism can have thousands of different proteins, and these proteins must cooperate to ensure the health of an organism. Proteins bind to other proteins and form complexes to carry out their functions. Many proteins interact with multiple other proteins creating a complex network of protein interactions. These interactions can be represented through maps depicting protein-protein interaction networks, represented as nodes and edges. Nodes are circles that are representative of a protein,... https://www.jove.com/v/12507 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13160.jpg Interactions Between Signaling Pathways Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli. Convergence and divergence, and cross-talk between signaling pathways Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response... https://www.jove.com/v/13160 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14899.jpg Integration of Synaptic Events Synaptic integration mainly includes the summation of graded potentials. Graded potentials, regardless of their type, cause subtle alterations in membrane voltage, resulting in either depolarization or hyperpolarization. These incremental changes, when combined or summed, can propel the neuron toward its threshold. Consider, for example, a membrane experiencing a +15 mV shift, causing it to depolarize from -70 mV to -55 mV. In this scenario, graded potentials govern the membrane's ability to... https://www.jove.com/v/14899 88 2025-06-13T16:06:36+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17242/17242_article_thumb_17242.jpg Pharmacodynamic Models: Link Model and Systems Pharmacodynamic Model The link model is a fundamental pharmacokinetic-pharmacodynamic (PK–PD) approach to account for delayed drug responses when the observed effect does not immediately correlate with the drug's plasma concentration peak. This delay is mathematically addressed by introducing an effect compartment concentration, Ce, which is kinetically linked to the plasma concentration, Cp, via a first-order rate constant, ke0. The linkage allows for a more accurate prediction of drug effects over time. A higher... https://www.jove.com/v/17242 74 2026-02-12T19:16:58+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40594/40594_article_thumb_40594_TN.jpg Applications of Integration to Find Blood Flow Blood flow through a cylindrical blood vessel can be mathematically described using the principles of laminar flow, a regime in which fluid moves smoothly in parallel layers. In this model, the velocity of the blood is not uniform across the cross-section of the vessel; rather, it varies with the radial distance from the center. The maximum velocity occurs along the central axis, decreasing progressively toward the vessel walls, where it reaches zero due to viscous drag.Approximating Blood... https://www.jove.com/v/40594 87 2026-01-12T20:24:36+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62796.jpg JUMPn: A Streamlined Application for Protein Co-Expression Clustering and Network Analysis in Proteomics We present a systems biology tool JUMPn to perform and visualize network analysis for quantitative proteomics data, with a detailed protocol including data pre-processing, co-expression clustering, pathway enrichment, and protein-protein interaction network analysis. https://www.jove.com/v/62796 448 2021-10-19T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63084.jpg Inherent Dynamics Visualizer, an Interactive Application for Evaluating and Visualizing Outputs from a Gene Regulatory Network Inference Pipeline The Inherent Dynamics Visualizer is an interactive visualization package that connects to a gene regulatory network inference tool for enhanced, streamlined generation of functional network models. The visualizer can be used to make more informed decisions for parameterizing the inference tool, thus increasing confidence in the resulting models. https://www.jove.com/v/63084 644 2021-12-07T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65150.jpg Modeling the Functional Network for Spatial Navigation in the Human Brain This paper presents an integrative approach to investigating the functional network for spatial navigation in the human brain. This approach incorporates a large-scale neuroimaging meta-analytic database, resting-state functional magnetic resonance imaging, and network modeling and graph-theoretical techniques. https://www.jove.com/v/65150 355 2023-10-13T20:20:00+00:00 JoVE no https://visualize.jove.com/18516243-uncovering-interactions-in-the-frequency-domain monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12276.jpg ¹H NMR: Interpreting Distorted and Overlapping Signals Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum. As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or... https://www.jove.com/v/12276 62 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16067.jpg Basic signals of Fourier Transform The Fourier Transform is a pivotal mathematical tool in signal processing, enabling the transformation of time-domain signals into their frequency-domain representations. Among the numerous elements within this domain, certain functions like the sinc function, delta function, and exponential signals hold significant importance due to their unique properties and implications. The sinc function, defined as sinc(x) = sin(πx)/(πx), is particularly notable for its symmetry and behavior at zero. It... https://www.jove.com/v/16067 67 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16074.jpg Discrete Fourier Transform The Discrete Fourier Transform (DFT) is a fundamental tool in signal processing, extending the discrete-time Fourier transform by evaluating discrete signals at uniformly spaced frequency intervals. This transformation converts a finite sequence of time-domain samples into frequency components, each representing complex sinusoids ordered by frequency. The DFT translates these sequences into the frequency domain, effectively indicating the magnitude and phase of each frequency component present... https://www.jove.com/v/16074 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16079.jpg Aliasing Accurate signal sampling and reconstruction are crucial in various signal-processing applications. A time-domain signal's spectrum can be revealed using its Fourier transform. When this signal is sampled at a specific frequency, it results in multiple scaled replicas of the original spectrum in the frequency domain. The spacing of these replicas is determined by the sampling frequency. If the sampling frequency is below the Nyquist rate, these replicas overlap, preventing the original signal... https://www.jove.com/v/16079 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16089.jpg Relation of DFT to z-Transform The Discrete Fourier Transform (DFT) is a crucial tool for analyzing the frequency content of discrete-time signals. It converts a sequence of N samples from the time domain into its corresponding sequence in the frequency domain, where each sample represents a specific frequency component. To understand how the DFT works, it's helpful to consider the z-transform, which is a method for representing discrete sequences in the complex frequency domain. The z-transform involves summing the terms of... https://www.jove.com/v/16089 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16128.jpg Frequency-Domain Interpretation of PD Control Proportional-Derivative (PD) controllers are widely used in fan control systems to improve stability and performance. A fan control system can be effectively represented using a Bode plot to illustrate the impact of a PD controller through its transfer function. The Bode plot visually conveys how PD control modifies the fan's response across various frequencies, providing a frequency domain interpretation of the controller's behavior. The proportional control gain, combined with the system's... https://www.jove.com/v/16128 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60249.jpg Statistical Modelling of Cortical Connectivity Using Non-invasive Electroencephalograms Standard EEG analysis techniques offer limited insight into nervous system function. Deriving statistical models of cortical connectivity offers far greater ability to investigate underlying network dynamics. Improved functional assessment opens new possibilities for diagnosis, prognostication, and outcome prediction in nervous system diseases. https://www.jove.com/v/60249 531 2019-11-01T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65347.jpg New Framework for Understanding Cross-Brain Coherence in Functional Near-Infrared Spectroscopy (fNIRS) Hyperscanning Studies Wavelet transform coherence (WTC) is a common methodology for assessing the coupling between signals that is used in functional near-infrared spectroscopy (fNIRS) hyperscanning studies. A toolbox for assessing the directionality of the signal interaction is presented in this work. https://www.jove.com/v/65347 359 2023-10-06T21:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67183.jpg Functional Near-Infrared Spectroscopy Hyperscanning Study in Psychological Counseling The protocol aims to provide a detailed description of the methodology for conducting an fNIRS hyperscanning study in psychological counseling. This includes the preparations for the experiment, the procedure for collecting data, and the subsequent data analysis process. https://www.jove.com/v/67183 364 2025-01-17T20:50:00+00:00 JoVE no https://visualize.jove.com/18522715-on-the-necessity-of-different-statistical-treatment-for-illumina-beadchip-and-affymetrix-genechip-data-and-its-significance-for-biological-interpretation monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12014.jpg DNA Microarrays Microarrays are high-throughput and relatively inexpensive assays that can be automated to analyze large quantities of data at a time. They are used in genome-wide studies to compare gene or protein expression under two varied conditions, such as healthy and diseased states. Microarrays consist of glass or silica slides on which probe molecules are covalently attached through surface functionalization. Most commonly, the slides are prepared through the chemisorption of silanes to silica... https://www.jove.com/v/12014 154 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50683.jpg Infinium Assay for Large-scale SNP Genotyping Applications A protocol is described that uses Illumina's Infinium assays to perform large-scale genotyping. These assays can reliably genotype millions of SNPs across hundreds of individual DNA samples in three days. Once generated, these genotypes can be used to check for associations with a variety of different diseases or phenotypes. https://www.jove.com/v/50683 813 2013-11-19T06:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56752.jpg Real-time Analysis of Transcription Factor Binding, Transcription, Translation, and Turnover to Display Global Events During Cellular Activation This protocol describes the combinatorial use of ChIP-seq, 4sU-seq, total RNA-seq, and ribosome profiling for cell lines and primary cells. It enables tracking changes in transcription-factor binding, de novo transcription, RNA processing, turnover and translation over time, and displaying the overall course of events in activated and/or rapidly changing cells. https://www.jove.com/v/56752 774 2018-03-07T05:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61060.jpg Optimization for Sequencing and Analysis of Degraded FFPE-RNA Samples This method describes the steps to improve the quality and quantity of sequence data that can be obtained from formalin-fixed paraffin-embedded (FFPE) RNA samples. We describe the methodology to more accurately assess the quality of FFPE-RNA samples, prepare sequencing libraries, and analyze the data from FFPE-RNA samples. https://www.jove.com/v/61060 450 2020-06-08T07:00:00+00:00 JoVE no https://visualize.jove.com/18529019-increasing-robustness-against-changes-in-the-interferent-structure-by-incorporating-prior-information-in-the-augmented-classical-least-squares-framework monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13630.jpg Residuals and Least-Squares Property The vertical distance between the actual value of y and the estimated value of y. In other words, it measures the vertical distance between the actual data point and the predicted point on the line If the observed data point lies above the line, the residual is positive, and the line underestimates the actual data value for y. If the observed data point lies below the line, the residual is negative, and the line overestimates the actual data value for y. The process of fitting the best-fit... https://www.jove.com/v/13630 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14511.jpg Propagation of Uncertainty from Random Error An experiment often consists of more than a single step. In this case, measurements at each step give rise to uncertainty. Because the measurements occur in successive steps, the uncertainty in one step necessarily contributes to that in the subsequent step. As we perform statistical analysis on these types of experiments, we must learn to account for the propagation of uncertainty from one step to the next. The propagation of uncertainty depends on the type of arithmetic operation performed on... https://www.jove.com/v/14511 59 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14512.jpg Propagation of Uncertainty from Systematic Error The atomic mass of an element varies due to the relative ratio of its isotopes. A sample's relative proportion of oxygen isotopes influences its average atomic mass. For instance, if we were to measure the atomic mass of oxygen from a sample, the mass would be a weighted average of the isotopic masses of oxygen in that sample. Since a single sample is not likely to perfectly reflect the true atomic mass of oxygen for all the molecules of oxygen on Earth, the mass we obtain from this particular... https://www.jove.com/v/14512 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14518.jpg Calibration Curves: Linear Least Squares A calibration curve is a plot of the instrument's response against a series of known concentrations of a substance. This curve is used to set the instrument response levels, using the substance and its concentrations as standards. Alternatively, or additionally, an equation is fitted to the calibration curve plot and subsequently used to calculate the unknown concentrations of other samples reliably. For data that follow a straight line, the standard method for fitting is the linear... https://www.jove.com/v/14518 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14819.jpg Atomic Absorption Spectroscopy: Interference Interference leads to systematic error in atomic absorption (AA) measurements by enhancing or diminishing the analytical signal or the background. These interferences can be grouped into three main categories: spectral interference, chemical interference, and physical interference. Spectral interference occurs when signals from other elements or molecules overlap with the analyte signal, falsely elevating or masking the analyte's absorbance. This interference can be corrected using Zeeman,... https://www.jove.com/v/14819 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16093.jpg Effects of feedback Feedback in control systems plays a critical role in shaping various operational parameters, extending beyond simple error reduction to influence stability, bandwidth, gain, impedance, and sensitivity. Understanding these effects requires examining a basic feedback system characterized by defined input, output, error, and feedback signals. Feedback significantly modifies the gain of a control system. The gain of a system without feedback is altered by a factor of one plus GH, where G represents... https://www.jove.com/v/16093 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62425.jpg ARL Spectral Fitting as an Application to Augment Spectral Data via Franck-Condon Lineshape Analysis and Color Analysis This protocol introduces Franck-Condon Lineshape Analyses (FCLSA) of emission spectra and serves as a tutorial for the use of ARL Spectral Fitting software. The open-source software provides an easy and intuitive way to perform advanced analysis of emission spectra including excited state energy calculations, CIE color coordinate determination, and FCLSA. https://www.jove.com/v/62425 431 2021-08-19T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66796.jpg Augmenting Large Language Models via Vector Embeddings to Improve Domain-Specific Responsiveness In this protocol, foundation large language model response quality is improved via augmentation with peer-reviewed, domain-specific scientific articles through a vector embedding mechanism. Additionally, code is provided to aid in performance comparison across large language models. https://www.jove.com/v/66796 194 2024-12-06T20:20:00+00:00 JoVE no https://visualize.jove.com/18568846-aaa-atpases-in-the-initiation-of-dna-replication monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3255.jpg Visualization of DNA Replication in the Vertebrate Model System DT40 using the DNA Fiber Technique DT40, a model vertebrate genetic system, provides a powerful tool to analyze protein function. Here we describe a simple method that allows qualitative analysis of parameters that influence DNA synthesis during the S-phase in DT40 cells at the single molecule level. https://www.jove.com/v/3255 438 2011-10-27T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/4449.jpg Study of the DNA Damage Checkpoint using Xenopus Egg Extracts Xenopus egg extract is a useful model system to investigate the DNA damage checkpoint. This protocol is for the preparation of Xenopus egg extracts and DNA damage checkpoint inducing reagents. These techniques are adaptable to a variety of DNA damaging approaches in the study of the DNA damage checkpoint signaling. https://www.jove.com/v/4449 655 2012-11-05T21:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11548.jpg The DNA Replication Fork An organism’s genome needs to be duplicated in an efficient and error-free manner for its growth and survival. The replication fork is a Y-shaped active region where two strands of DNA are separated and replicated continuously. The coupling of DNA unzipping and complementary strand synthesis is a characteristic feature of a replication fork. Organisms with small circular DNA, such as E. coli, often have a single origin of replication; therefore, they have only two replication forks, one in... https://www.jove.com/v/11548 62 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11551.jpg DNA Helicases DNA unwinding helicase enzymes are a type of motor protein. Motor proteins can translocate along filaments or polymers using energy generated from ATP hydrolysis. Helicases are involved in all the important cellular processes where DNA unwinding is required, such as DNA replication, repair, recombination, and transcription. They are present in all living organisms, but vary in their structure, function, and mechanism of action. For example, in prokaryotes, DnaB helicase binds and translocates... https://www.jove.com/v/11551 55 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11566.jpg DNA Damage can Stall the Cell Cycle In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at... https://www.jove.com/v/11566 156 2025-12-12T21:27:29+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11568.jpg Restarting Stalled Replication Forks DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a... https://www.jove.com/v/11568 157 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11548.jpg The DNA Replication Fork An organism’s genome needs to be duplicated in an efficient and error-free manner for its growth and survival. The replication fork is a Y-shaped active region where two strands of DNA are separated and replicated continuously. The coupling of DNA unzipping and complementary strand synthesis is a characteristic feature of a replication fork. Organisms with small circular DNA, such as E. coli, often have a single origin of replication; therefore, they have only two replication forks, one in... https://www.jove.com/v/13191 62 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11568.jpg Restarting Stalled Replication Forks DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a... https://www.jove.com/v/13206 157 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67120.jpg Strand-Specific Analysis of Proteins at Replicating DNA Strands by Enrichment and Sequencing of Protein-Associated Nascent DNA Method Enrichment and sequencing of protein-associated nascent DNA (eSPAN) was developed to detect the relative abundance of a chromatin-associated protein on two replicating DNA strands, thereby revealing molecular insight into chromatin replication and its coupled processes. This protocol describes eSPAN procedures in yeast and mouse embryonic stem (ES) cells. https://www.jove.com/v/67120 533 2025-05-02T19:45:00+00:00 JoVE no https://visualize.jove.com/18601481-design-of-fast-state-observers-using-a-backstepping-like-approach-with-application-to-synchronization-of-chaotic-systems monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16047.jpg Linear time-invariant Systems A system is linear if it displays the characteristics of homogeneity and additivity, together termed the superposition property. This principle is fundamental in all linear systems. Linear time-invariant (LTI) systems include systems with linear elements and constant parameters. The input-output behavior of an LTI system can be fully defined by its response to an impulsive excitation at its input. Once this impulse response is known, the system's reaction to any other input can be calculated... https://www.jove.com/v/16047 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16053.jpg BIBO stability of continuous and discrete -time systems System stability is a fundamental concept in signal processing, often assessed using convolution. For a system to be considered bounded-input bounded-output (BIBO) stable, any bounded input signal must produce a bounded output signal. A bounded input signal is one where the modulus does not exceed a certain constant at any point in time. To determine the BIBO stability, the convolution integral is utilized when a bounded continuous-time input is applied to a Linear Time-Invariant (LTI) system. https://www.jove.com/v/16053 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16100.jpg State Space Representation The frequency-domain technique, commonly used in analyzing and designing feedback control systems, is effective for linear, time-invariant systems. However, it falls short when dealing with nonlinear, time-varying, and multiple-input multiple-output systems. The time-domain or state-space approach addresses these limitations by utilizing state variables to construct simultaneous, first-order differential equations, known as state equations, for an nth-order system. Consider an RLC circuit, a... https://www.jove.com/v/16100 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16103.jpg Linear Approximation in Time Domain Nonlinear systems often require sophisticated approaches for accurate modeling and analysis, with state-space representation being particularly effective. This method is especially useful for systems where variables and parameters vary with time or operating conditions, such as in a simple pendulum or a translational mechanical system with nonlinear springs. For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length, the... https://www.jove.com/v/16103 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16112.jpg First Order Systems First-order systems, such as RC circuits, are foundational in understanding dynamic systems due to their straightforward input-output relationship. Analyzing their responses to different input functions under zero initial conditions reveals significant insights into system behavior. When a first-order system is subjected to a unit-step input, its response is characterized by its transfer function. By applying the Laplace transform of the unit-step input to the transfer function, expanding the... https://www.jove.com/v/16112 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16114.jpg Second Order systems II In an underdamped second-order system, where the damping ratio ζ is between 0 and 1, a unit-step input results in a transfer function that, when transformed using the inverse Laplace method, reveals the output response. The output exhibits a damped sinusoidal oscillation, and the difference between the input and output is termed the error signal. This error signal also demonstrates damped oscillatory behavior. Eventually, as the system reaches a steady state, the error diminishes to zero. If ζ... https://www.jove.com/v/16114 78 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56205.jpg Bouncing Ball with a Uniformly Varying Velocity in a Metronome Synchronization Task The purpose of this protocol is to introduce the application of a bouncing ball with a uniformly varying velocity in a metronome synchronization task. https://www.jove.com/v/56205 304 2017-09-21T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59898.jpg A Method for Tracking the Time Evolution of Steady-State Evoked Potentials A protocol to assess the time evolution of the neural entrainment to external repetitive stimuli is presented. Steady-state recordings of the same experimental condition are acquired and averaged in the time-domain. The steady-state dynamics are analyzed by plotting the response amplitude as a function of time. https://www.jove.com/v/59898 723 2019-05-25T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68955.jpg Age-dependent Dynamics of Locomotion in Caenorhabditis elegans : A Lyapunov Exponent Analysis This study examines the effect of age on locomotion in C. elegans by measuring the largest Lyapunov exponent (LLE). As they age, C. elegans show an increase and subsequent decline in motor control. Results show a peak LLE at five days, followed by a decline as the worms age. https://www.jove.com/v/68955 404 2025-09-23T21:45:00+00:00 JoVE no https://visualize.jove.com/18601805-empirical-comparison-of-subgroup-effects-in-conventional-and-individual-patient-data-meta-analyses monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11025.jpg Group Design The most basic experimental design involves two groups: the experimental group and the control group. The two groups are designed to be the same except for one difference— experimental manipulation. The experimental group gets the experimental manipulation—that is, the treatment or variable being tested—and the control group does not. Since experimental manipulation is the only difference between the experimental and control groups, we can be sure that any differences between the two are due to... https://www.jove.com/v/11025 121 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16470.jpg Analysis of Population Pharmacokinetic Data Analysis of population pharmacokinetic data involves studying the behavior of drugs within diverse populations to understand their pharmacokinetic parameters. Traditional pharmacokinetic methods typically involve collecting samples from a few individuals and estimating these parameters. While these methods are commonly used, they have limitations in capturing the variability in drug response among individuals or heterogeneous populations. Population pharmacokinetics is employed to address these... https://www.jove.com/v/16470 72 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16484.jpg Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches Biopharmaceutical studies constitute a vital field aiming to enhance drug delivery methods and refine therapeutic approaches, drawing upon diverse interdisciplinary knowledge. In research methodologies, the choice between controlled and non-controlled studies significantly influences the study's reliability and accuracy. Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast, controlled... https://www.jove.com/v/16484 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16585.jpg Mechanistic Models: Compartment Models in Individual and Population Analysis Mechanistic models are utilized in individual analysis using single-source data, but imperfections arise due to data collection errors, preventing perfect prediction of observed data. The mathematical equation involves known values (Xi), observed concentrations (Ci), measurement errors (εi), model parameters (ϕj), and the related function (ƒi) for i number of values. Different least-squares metrics quantify differences between predicted and observed values. The ordinary least squares (OLS)... https://www.jove.com/v/16585 83 JoVE no https://cloudfront.jove.com/files/ftp_upload/17157/17157_article_thumb_17157.jpg Bioequivalence Data: Statistical Interpretation The statistical interpretation of bioequivalence data is a significant aspect of pharmaceutical research. Bioequivalence refers to the absence of any significant difference in the rate and extent to which the active ingredient in pharmaceutical products becomes available at the site of drug action when administered at the same molar dose under similar conditions. This helps determine if different drug products have similar absorption rates, ensuring their interchangeability.Statistical... https://www.jove.com/v/17157 76 2026-03-02T20:57:38+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17620.jpg Comparing the Survival Analysis of Two or More Groups Survival analysis is a cornerstone of medical research, used to evaluate the time until an event of interest occurs, such as death, disease recurrence, or recovery. Unlike standard statistical methods, survival analysis is particularly adept at handling censored data—instances where the event has not occurred for some participants by the end of the study or remains unobserved. To address these unique challenges, specialized techniques like the Kaplan-Meier estimator, log-rank test, and Cox... https://www.jove.com/v/17620 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59825.jpg Inverse Probability of Treatment Weighting (Propensity Score) using the Military Health System Data Repository and National Death Index When randomized controlled trials are not feasible, a comprehensive health care data source like the Military Health System Data Repository provides an attractive alternative for retrospective analyses. Incorporating mortality data from the national death index and balancing differences between groups using propensity weighting helps reduce biases inherent in retrospective designs. https://www.jove.com/v/59825 415 2020-01-08T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59841.jpg Meta-analysis of Voxel-Based Neuroimaging Studies using Seed-based d Mapping with Permutation of Subject Images (SDM-PSI) We detail how to conduct a meta-analysis of voxel-based neuroimaging studies using Seed-based d Mapping with Permutation of Subject Images (SDM-PSI). https://www.jove.com/v/59841 386 2019-11-27T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60035.jpg Applying an eMASS Customization Program as a Research Tool to Evaluate Consumer Benefits Presented here is a protocol to examine consumer responses toward mass customization in the context of online retailing. The protocol details the online survey procedure and how to analyze data using structural equation modeling and group differences using latent mean analyses. https://www.jove.com/v/60035 507 2019-09-27T20:30:00+00:00 JoVE no https://visualize.jove.com/18629283-reproducibility-assessment-of-independent-component-analysis-of-expression-ratios-from-dna-microarrays monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2279.jpg An Allele-specific Gene Expression Assay to Test the Functional Basis of Genetic Associations Genetic associations often remain unexplained at a functional level. This method aims to assess the effect of phenotype-associated genetic markers on gene expression by analyzing cells heterozygous for transcribed SNPs. The technology allows accurate measurement by MALDI-TOF mass spectrometry to quantify allele-specific primer extension products. https://www.jove.com/v/2279 617 2010-11-03T23:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12014.jpg DNA Microarrays Microarrays are high-throughput and relatively inexpensive assays that can be automated to analyze large quantities of data at a time. They are used in genome-wide studies to compare gene or protein expression under two varied conditions, such as healthy and diseased states. Microarrays consist of glass or silica slides on which probe molecules are covalently attached through surface functionalization. Most commonly, the slides are prepared through the chemisorption of silanes to silica... https://www.jove.com/v/12014 154 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61060.jpg Optimization for Sequencing and Analysis of Degraded FFPE-RNA Samples This method describes the steps to improve the quality and quantity of sequence data that can be obtained from formalin-fixed paraffin-embedded (FFPE) RNA samples. We describe the methodology to more accurately assess the quality of FFPE-RNA samples, prepare sequencing libraries, and analyze the data from FFPE-RNA samples. https://www.jove.com/v/61060 450 2020-06-08T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62566.jpg Analyzing Multifactorial RNA-Seq Experiments with DiCoExpress DiCoExpress is a script-based tool implemented in R to perform an RNA-Seq analysis from quality control to co-expression. DiCoExpress handles complete and unbalanced design up to 2 biological factors. This video tutorial guides the user through the different features of DiCoExpress. https://www.jove.com/v/62566 322 2022-07-29T19:30:00+00:00 JoVE no https://visualize.jove.com/18640345-isolated-giant-aortic-aneurysm-in-an-infant-ehlers-danlos-syndrome-type-iv monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17904/17904_article_thumb_17904.jpg Aortic Regurgitation II: Clinical Features and Diagnostic Tests Aortic valve regurgitation (AR) occurs when the aortic valve fails to close properly, allowing blood to flow backward from the aorta into the left ventricle. This backflow can result in two distinct clinical presentations: acute and chronic AR, each characterized by its own set of symptoms and physical findings.Acute Aortic RegurgitationAcute AR presents with a sudden onset of severe symptoms. Patients typically experience profound dyspnea (shortness of breath), chest pain, and signs of left... https://www.jove.com/v/17904 82 2025-06-19T14:46:00+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17919/17919_article_thumb_17919.jpg Rheumatic Heart Disease I: Introduction Rheumatic heart disease or RHD is a chronic condition that results from rheumatic fever, causing permanent damage to the heart valves.Etiology and Risk FactorsIt primarily arises from rheumatic fever, an inflammatory disease that can develop after untreated or inadequately treated group A streptococcal (GAS) pharyngitis. Streptococcus spreads through direct contact with oral or respiratory secretions. While the bacteria are the causative agents, factors like malnutrition, overcrowding, poor... https://www.jove.com/v/17919 83 2025-06-19T16:25:14+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17960/17960_article_thumb_17960.jpg Cardiomyopathy III: Hypertrophic Cardiomyopathy Hypertrophic cardiomyopathy, or HCM, is an autosomal dominant genetic disorder characterized by asymmetric left ventricular hypertrophy without ventricular dilation. It is more common in men and is typically diagnosed in young, athletic adults.EtiologyHCM is primarily genetic and is caused by mutations in genes encoding sarcomeric proteins. Researchers have identified over 1400 mutations across at least 11 different genes. Among these, the most frequently occurring mutations are found in the... https://www.jove.com/v/17960 89 2025-08-11T17:09:32+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17979/17979_article_thumb_17979.jpg Aneurysm I: Introduction An aortic aneurysm is a localized outpouching or dilation at a weak point in the artery wall. It may involve different parts of the aorta, such as the abdominal aorta, aortic arch, or thoracic aorta.Etiological factorsSeveral disorders are associated with aortic aneurysms.Congenital causes, such as primary connective tissue disorders like Marfan syndrome, impact the integrity and strength of connective tissues, notably affecting the aorta. Marfan syndrome is a genetic disorder that specifically... https://www.jove.com/v/17979 90 2025-06-19T16:19:01+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17980/17980_article_thumb_17980.jpg Aneurysm II: Clinical Manifestations and Diagnostic Studies Thoracic, aortic arch and abdominal aneurysms are significant vascular conditions that can present with various clinical manifestations and lead to serious complications. Understanding these manifestations and the appropriate diagnostic studies is essential for effective management and treatment.Thoracic Aortic AneurysmsThoracic aortic aneurysms often remain asymptomatic until they reach a size that impinges on adjacent structures. They typically cause deep, diffuse chest pain that radiates to... https://www.jove.com/v/17980 81 2025-06-19T16:19:14+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17981/17981_article_thumb_17981.jpg Aneurysm III: Interprofessional Care Aneurysm management involves either conservative medical therapy or surgical intervention, depending on the size and symptoms of the aneurysm. Conservative management is generally reserved for smaller, asymptomatic aneurysms, while larger or symptomatic aneurysms often necessitate surgical repair.Conservative Medical TherapyFor small, asymptomatic aneurysms, particularly abdominal aortic aneurysms (AAA) less than 5.5 centimeters in diameter, conservative medical therapy is recommended. This... https://www.jove.com/v/17981 86 2025-06-19T16:19:25+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56039.jpg Using In Vivo and Tissue and Cell Explant Approaches to Study the Morphogenesis and Pathogenesis of the Embryonic and Perinatal Aorta Protocols for studying the embryonic and perinatal murine aorta using in vivo clonal analysis and fate mapping, aortic explants, and isolated smooth muscle cells are detailed here. These diverse approaches facilitate the investigation of the morphogenesis of the embryonic and perinatal aorta in normal development and the pathogenesis in disease. https://www.jove.com/v/56039 657 2017-09-12T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68033.jpg Novel and Innovative Hybrid Technique for Type A Aortic Dissection The protocol describes ascending aortic replacement combined with endovascular coverage of the entire aortic arch with a fenestrated stent graft in a patient with acute type A aortic dissection in the absence of a tear in the aortic arch. https://www.jove.com/v/68033 386 2025-03-28T21:55:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68211.jpg Modified Octopus Technique for Thoracoabdominal Aortic Aneurysm This study describes a modified octopus technique for endovascular treatment of thoracoabdominal aortic aneurysms, demonstrating favorable clinical outcomes. https://www.jove.com/v/68211 296 2025-08-01T19:50:00+00:00 JoVE no https://visualize.jove.com/18680598-novel-genes-dramatically-alter-regulatory-network-topology-in-amphioxus monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11606.jpg Regulation of Expression Occurs at Multiple Steps Gene expression can be regulated at almost every step from gene to protein. Transcription is the step that is most commonly regulated. This involves the binding of proteins to short regulatory sequences on the DNA. This association can either promote or inhibit the transcription of a gene associated with the respective sequence. Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a... https://www.jove.com/v/11606 144 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11607.jpg Cis-regulatory Sequences Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are... https://www.jove.com/v/11607 122 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11993.jpg Exon Recombination The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes. Exon shuffling follows “splice frame rules.” Each exon has three reading... https://www.jove.com/v/11993 152 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11606.jpg Regulation of Expression Occurs at Multiple Steps Gene expression can be regulated at almost every step from gene to protein. Transcription is the step that is most commonly regulated. This involves the binding of proteins to short regulatory sequences on the DNA. This association can either promote or inhibit the transcription of a gene associated with the respective sequence. Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a... https://www.jove.com/v/13142 144 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11607.jpg Cis-regulatory Sequences Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are... https://www.jove.com/v/13143 122 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13949.jpg Regulation of Expression at Multiple Steps The gene expression in cells is regulated at different stages: (i) transcription, (ii) RNA processing, (iii) RNA localization, and (iv) translation. Transcriptional regulation is mediated by regulatory proteins such as transcription factors, activators, or repressors—these control gene expression by initiating or inhibiting the transcription of genes. Once a precursor or pre-mRNA is produced, it undergoes post-transcriptional modification, including 5' capping, splicing, and the addition of a... https://www.jove.com/v/13949 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52042.jpg Expression of Fluorescent Proteins in Branchiostoma lanceolatum by mRNA Injection into Unfertilized Oocytes We report here the robust and efficient expression of fluorescent proteins after mRNA injection into unfertilized oocytes of Branchiostoma lanceolatum. The development of the microinjection technique in this basal chordate will pave the way for far-reaching technical innovations in this emerging model system, including in vivo imaging and gene-specific manipulations. https://www.jove.com/v/52042 571 2015-01-12T20:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53474.jpg Stem cell-like Xenopus Embryonic Explants to Study Early Neural Developmental Features In Vitro and In Vivo In Xenopus embryos, cells from the roof of the blastocoel are pluripotent and can be programmed to generate various tissues. Here, we describe protocols to use amphibian blastocoel roof explants as an assay system to investigate key in vivo and in vitro features of early neural development. https://www.jove.com/v/53474 673 2016-02-02T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55113.jpg The Power of Simplicity: Sea Urchin Embryos as in Vivo Developmental Models for Studying Complex Cell-to-cell Signaling Network Interactions This video article details a straightforward in vivo methodology that can be used to systematically and efficiently characterize components of complex signaling pathways and regulatory networks in many invertebrate embryos. https://www.jove.com/v/55113 454 2017-02-16T22:00:00+00:00 JoVE no https://visualize.jove.com/18694574-intermittent-adenosine-at-the-beginning-of-reperfusion-does-not-trigger-cardioprotection monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17931/17931_article_thumb_17931.jpg Acute Coronary Syndrome IV: Interprofessional Care IntroductionThe management of Acute Coronary Syndrome (ACS) aims to minimize myocardial damage, preserve myocardial function, and prevent complications.Initial ManagementInpatient management involves continuous cardiac monitoring, preferably in an ICU, focusing on blood pressure, serum sodium, potassium, and creatinine levels, and urine output. Ongoing pharmacologic management is crucial for stabilizing the patient.Supplemental Oxygen: Administer supplemental oxygen if oxygen saturation is... https://www.jove.com/v/17931 88 2025-06-19T16:29:05+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17949/17949_article_thumb_17949.jpg Cardiopulmonary Resuscitation IV: Pharmacological Management Pharmacologic intervention is crucial in treating cardiac arrest patients during ACLS or Advanced Cardiovascular Life Support. The ACLS algorithms guide the administration of specific drugs based on the patient's cardiac arrest rhythm, which includes pulseless ventricular tachycardia (VT), ventricular fibrillation (VF), asystole, and pulseless electrical activity (PEA).EpinephrineIndication: Epinephrine is the first-line drug for all cardiac arrest rhythms.Mechanism of Action: Epinephrine... https://www.jove.com/v/17949 85 2025-07-31T20:24:37+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51269.jpg Myocardial Infarction and Functional Outcome Assessment in Pigs This protocol describes the porcine myocardial infarction (MI) model using a 90 min closed-chest coronary balloon occlusion of the left anterior descending artery (LAD), followed by reperfusion. Furthermore, the protocol for several outcome parameters, such as cardiac function, hemodynamics, microvascular resistance, and infarct size, are also presented. https://www.jove.com/v/51269 723 2014-04-25T20:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59672.jpg Postconditioning with Lactate-enriched Blood for Cardioprotection in ST-segment Elevation Myocardial Infarction Herein, we present a protocol for postconditioning with lactate-enriched blood, which is a novel approach for cardioprotection. This protocol comprises intermittent reperfusion and timely coronary injections of lactated Ringer's solution. This can be applied to ST-segment elevation myocardial infarction patients who undergo primary percutaneous coronary intervention. https://www.jove.com/v/59672 326 2019-05-28T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64752.jpg Model of Ischemia and Reperfusion Injury in Rabbits The present study demonstrates a highly reproducible animal model of acute regional myocardial ischemia and reperfusion injury in rabbits using a left mini-thoracotomy for survival cases or a midline sternotomy for non-survival cases. https://www.jove.com/v/64752 371 2023-11-03T20:40:00+00:00 JoVE no https://visualize.jove.com/18727907-multisensory-integration-a-functional-role-for-inter-area-synchronization monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13160.jpg Interactions Between Signaling Pathways Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli. Convergence and divergence, and cross-talk between signaling pathways Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response... https://www.jove.com/v/13160 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14899.jpg Integration of Synaptic Events Synaptic integration mainly includes the summation of graded potentials. Graded potentials, regardless of their type, cause subtle alterations in membrane voltage, resulting in either depolarization or hyperpolarization. These incremental changes, when combined or summed, can propel the neuron toward its threshold. Consider, for example, a membrane experiencing a +15 mV shift, causing it to depolarize from -70 mV to -55 mV. In this scenario, graded potentials govern the membrane's ability to... https://www.jove.com/v/14899 88 2025-06-13T16:06:36+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14931.jpg Sensory Modalities Sensation typically is the process by which the sensory receptors and sense organs detect stimuli from the internal and external environment and transmit this information to the central nervous system for processing. General senses refer to the broad category of sensory information detected by receptors in the body and can be further grouped into somatic and visceral senses. Somatic sensations include touch, pressure, temperature, and pain and are essential for navigating our environment and... https://www.jove.com/v/14931 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14933.jpg Sensory Perception: Organization of the Somatosensory System The somatosensory system is the central and peripheral nervous system component that senses and processes touch, pressure, pain, temperature, and body position or proprioception. The process of sensation takes place at three levels: The receptor level: The receptor level is the first stage of sensation. It involves the detection of a stimulus by specialized sensory receptors. The stimulus must arrive within the receptor's receptive field. Next, the receptor converts the energy of the stimulus... https://www.jove.com/v/14933 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14935.jpg Major Somatic Sensory Pathways Sensory impulses related to touch, pressure, vibration, and proprioception from various body parts, such as the limbs, trunk, neck, and posterior head, travel to the cerebral cortex through the posterior column-medial lemniscus pathway. The pathway’s name derives from the two white-matter tracts that convey the impulses: the spinal cord's posterior column and the brainstem's medial lemniscus. First-order sensory neurons extend their axons into the spinal cord, forming the posterior columns... https://www.jove.com/v/14935 88 JoVE no https://cloudfront.jove.com/files/ftp_upload/40862/40862_article_thumb_40862.jpg Inhibitors of Viral Protein Synthesis Protein synthesis is indispensable for viral replication, as viruses lack the cellular machinery required for this process and must hijack the host's translational apparatus. In response, host cells deploy a critical innate immune defense involving interferons, specialized cytokines that play a central role in inhibiting viral propagation.Upon viral detection, infected cells release interferons that bind to receptors on adjacent uninfected cells, activating the JAK-STAT signaling pathway and... https://www.jove.com/v/40862 90 2026-03-12T20:36:03+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52677.jpg Testing Sensory and Multisensory Function in Children with Autism Spectrum Disorder We describe how to implement a battery of behavioral tasks to examine the processing and integration of sensory stimuli in children with ASD. The goal is to characterize individual differences in temporal processing of simple auditory and visual stimuli and relate these to higher order perceptual skills like speech perception. https://www.jove.com/v/52677 553 2015-04-22T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62801.jpg How to Calculate and Validate Inter-brain Synchronization in a fNIRS Hyperscanning Study The dynamics between coupled brains of individuals have been increasingly represented by inter-brain synchronization (IBS) when they coordinate with each other, mostly using simultaneous-recording signals of brains (namely hyperscanning) with fNIRS. In fNIRS hyperscanning studies, IBS has been commonly assessed through the wavelet transform coherence (WTC) method because of its advantage on expanding time series into time-frequency space where oscillations can be seen in a highly intuitive way. https://www.jove.com/v/62801 333 2021-09-08T21:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65347.jpg New Framework for Understanding Cross-Brain Coherence in Functional Near-Infrared Spectroscopy (fNIRS) Hyperscanning Studies Wavelet transform coherence (WTC) is a common methodology for assessing the coupling between signals that is used in functional near-infrared spectroscopy (fNIRS) hyperscanning studies. A toolbox for assessing the directionality of the signal interaction is presented in this work. https://www.jove.com/v/65347 359 2023-10-06T21:15:00+00:00 JoVE no https://visualize.jove.com/18786388-modelling-biological-rhythms monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4234.jpg Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters Circadian clocks function within individual cells, i.e., they are cell-autonomous. Here, we describe methods for generating cell-autonomous clock models using non-invasive, luciferase-based real-time bioluminescence technology. Reporter cells provide tractable, functional model systems for studying circadian biology. https://www.jove.com/v/4234 638 2012-09-27T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11116.jpg Biological Clocks and Seasonal Responses The circadian—or biological—clock is an intrinsic, timekeeping, molecular mechanism that allows plants to coordinate physiological activities over 24-hour cycles called circadian rhythms. Photoperiodism is a collective term for the biological responses of plants to variations in the relative lengths of dark and light periods. The period of light-exposure is called the photoperiod. One example of photoperiodism in plants is seasonal flowering. Scientists believe that plants are cued to flower... https://www.jove.com/v/11116 165 2025-10-23T18:48:35+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12000.jpg Circadian Rhythms and Gene Regulation The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent years,... https://www.jove.com/v/12000 139 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12000.jpg Circadian Rhythms and Gene Regulation The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent years,... https://www.jove.com/v/13335 139 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16555.jpg Clearance Models: Physiological Models Drug clearance is a critical pharmacokinetic process involving the irreversible removal of drugs from the body through various organs over a specified time period. Physiological models are indispensable in determining organ-specific clearance, defined by the proportion of the drug eliminated per unit of time from the organ's blood volume. The organ's clearance rate depends on the blood flow to the organ and the extraction ratio (E). The extraction ratio describes the organ's proficiency in drug... https://www.jove.com/v/16555 69 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16587.jpg Model Approaches for Pharmacokinetic Data: Physiological Models Physiological models in pharmacokinetics are instrumental in understanding the distribution and elimination of drugs within the body. These models describe the drug concentration within target organs, influenced by factors such as drug uptake, tissue volume, and blood flow. Drug uptake is governed by the partition coefficient, which signifies the drug concentration ratio in tissue to that in the blood. The blood flow rate to a specific tissue is expressed as Qt, and the rate of change in tissue... https://www.jove.com/v/16587 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16606.jpg Chronopharmacokinetics: Circadian Rhythms and Influence on Drug Response Circadian rhythms are cyclic changes that are crucial in plasma drug concentrations. Various standard circadian parameters, including core body temperature, heart rate, and other cardiovascular factors, directly impact disease states and the therapeutic response to drug therapy. The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of... https://www.jove.com/v/16606 75 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54673.jpg Parallel Measurement of Circadian Clock Gene Expression and Hormone Secretion in Human Primary Cell Cultures Here, we describe settings to monitor in parallel circadian bioluminescence and the secretory activity of human islet cells and primary myotubes. For this, we employed lentiviral gene delivery of a luciferase core clock reporter, followed by in vitro synchronization and collection of outflow medium by continuous cell perifusion. https://www.jove.com/v/54673 413 2016-11-11T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60448.jpg Human Circadian Phenotyping and Diurnal Performance Testing in the Real World Here, we present a method to investigate diurnal rhythms in performance following accurate categorization of participants into circadian phenotype groups based on the Munich ChronoType Questionnaire, gold standard circadian phase biomarkers and actigraphic measures. https://www.jove.com/v/60448 616 2020-04-07T20:00:00+00:00 JoVE no https://visualize.jove.com/18849984-millisecond-scale-differences-in-neural-activity-in-auditory-cortex-can-drive-decisions monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3598.jpg Behavioral Determination of Stimulus Pair Discrimination of Auditory Acoustic and Electrical Stimuli Using a Classical Conditioning and Heart-rate Approach The application of a classical fear conditioning behavioral paradigm for auditory prosthetic research in rats is described. This paradigm provides a mechanism for identifying both detection of, and discrimination between, distinct acoustic and electrical stimuli using heart-rate as an outcome measure. https://www.jove.com/v/3598 650 2012-06-06T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10853.jpg Hearing When we hear a sound, our nervous system is detecting sound waves—pressure waves of mechanical energy traveling through a medium. The frequency of the wave is perceived as pitch, while the amplitude is perceived as loudness. Sound waves are collected by the external ear and amplified as they travel through the ear canal. When sounds reach the junction between the outer and middle ear, they vibrate the tympanic membrane—the eardrum. The resulting mechanical energy causes the attached ossicles—a... https://www.jove.com/v/10853 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10855.jpg The Cochlea The cochlea is a coiled structure in the inner ear that contains hair cells—the sensory receptors of the auditory system. Sound waves are transmitted to the cochlea by small bones attached to the eardrum called the ossicles, which vibrate the oval window that leads to the inner ear. This causes fluid in the chambers of the cochlea to move, vibrating the basilar membrane. The basilar membrane extends from the basal end of the cochlea near the oval window to the apical end at its tip. Although... https://www.jove.com/v/10855 73 2025-10-23T18:49:24+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14970.jpg Auditory Pathway Auditory pathways constitute the complex neural circuits responsible for transmitting and interpreting auditory information from the peripheral auditory system to the brain. Sound waves are initially captured by the outer ear, funneled through the ear canal, and reach the tympanic membrane (eardrum). These vibrations are transmitted via the middle ear's ossicles to the inner ear's cochlea. When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking the... https://www.jove.com/v/14970 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17771.jpg Auditory Perception The auditory system is essential for sound perception, utilizing various critical structures. When sound waves enter the outer ear, they travel through the ear canal and cause the eardrum to vibrate. These vibrations are then transmitted to the middle ear, where three tiny bones – the malleus, incus, and stapes – amplify the sound. This amplification is crucial, as it ensures that the sound vibrations are strong enough to be conveyed to the inner ear. These vibrations then reach the cochlea, a... https://www.jove.com/v/17771 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17772.jpg Perceiving Loudness, Pitch, and Location The human brain perceives pitch through two primary mechanisms reflected in place theory and frequency theory. Each mechanism describes how sound waves are interpreted as specific pitches by the brain, offering insights into the intricate processes of auditory perception. Place theory, or place coding, suggests that different pitches are heard because various sound waves activate specific locations along the cochlea's basilar membrane. The brain determines the pitch of a sound by identifying... https://www.jove.com/v/17772 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52420.jpg Infant Auditory Processing and Event-related Brain Oscillations High-density electroencephalography (dEEG) is being used increasingly to study brain development and plasticity in the early years of life. Here we present an application of sophisticated analysis techniques that builds on traditional EEG recording to understand the oscillatory dynamics of rapid auditory processing in the infant brain. https://www.jove.com/v/52420 394 2015-07-01T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53002.jpg Combined Shuttle-Box Training with Electrophysiological Cortex Recording and Stimulation as a Tool to Study Perception and Learning Shuttle-box avoidance learning is well-established in behavioral neuroscience. This protocol describes how shuttle-box learning in rodents can be combined with site-specific electrical intracortical microstimulation (ICMS) and simultaneous chronical in vivo recordings as a tool to study multiple aspects of learning and perception. https://www.jove.com/v/53002 523 2015-10-22T22:00:00+00:00 JoVE no https://visualize.jove.com/18924679-computer-assisted-automatic-synthesis-ii-development-of-a-fully-automated-apparatus-for-preparing-substituted-n-carboxyalkylamino-acids monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12371.jpg Preparation of Amides Amides are synthesized by treating carboxylic acids with amines in the presence of dehydrating agents like dicyclohexylcarbodiimide (DCC). The DCC-promoted synthesis of amides begins with the protonation of DCC by carboxylic acid. The protonation makes it a better acceptor. Next, the addition of carboxylate to the protonated carbodiimide gives a reactive acylating agent. Subsequently, the amine acts as a nucleophile that attacks the acylating agent to form a tetrahedral intermediate. In the... https://www.jove.com/v/12371 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12529.jpg Preparation of Amines: Alkylation of Ammonia and Amines Alkylation is one of the methods used to prepare amines. Direct alkylation of ammonia or a primary amine with an alkyl halide gives polyalkylated amines along with a quaternary ammonium salt through successive SN2 reactions. This process of making the quaternary salt through the direct alkylation method is called exhaustive alkylation. Each alkylation step makes the nitrogen center more nucleophilic, which triggers successive alkylations until a quaternary ammonium salt is formed. Considering... https://www.jove.com/v/12529 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12533.jpg Preparation of 1° Amines: Hofmann and Curtius Rearrangement Overview In the presence of an aqueous base and a halogen, primary amides can lose the carbonyl (as carbon dioxide) and undergo rearrangement to form primary amines. This reaction, called the Hofmann rearrangement, can produce primary amines (aryl and alkyl) in high yields without contamination by secondary and tertiary amines. In the Curtius rearrangement, acyl azides are converted into primary amines under thermal conditions, accompanied by the loss of gaseous N2 and CO2. The loss of nitrogen acts as... https://www.jove.com/v/12533 67 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12534.jpg Amines to Amides: Acylation of Amines Various carboxylic acid derivatives (such as acid chlorides, esters, and anhydrides) can be used for the acylation of amines to yield amides. The reaction requires two equivalents of amines. The first amine molecule functions as a nucleophile and attacks the carbonyl carbon to produce a tetrahedral intermediate. This is followed by the loss of the leaving group and restoration of the C=O bond. Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary amide... https://www.jove.com/v/12534 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12859.jpg Preparation of 1° Amines: Gabriel Synthesis Direct alkylation is not a suitable method for synthesizing amines because it produces polyalkylated products. Gabriel synthesis is the most preferred method to exclusively make primary amines. The method uses phthalimide, which contains a protected form of nitrogen that participates in alkylation only once to predominantly give primary amines. Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an... https://www.jove.com/v/12859 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12862.jpg Preparation of 1° Amines: Hofmann and Curtius Rearrangement Mechanism The Hofmann and Curtius rearrangement reactions can be applied to synthesize primary amines from carboxylic acid derivatives such as amides and acyl azides. In the Hofmann rearrangement, a primary amide undergoes deprotonation in the presence of a base, followed by halogenation to generate an N-haloamide. A second proton abstraction produces a stabilized anionic species, which rearranges to an isocyanate intermediate via an alkyl group migration from the carbonyl carbon to the neighboring... https://www.jove.com/v/12862 86 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55677.jpg Hydrolysis of a Ni-Schiff-Base Complex Using Conditions Suitable for Retention of Acid-labile Protecting Groups Here, we present an efficient hydrolysis and subsequent Fmoc protection of an amino acid isolated from a Ni-Schiff-base complex. Hydrolysis conditions presented here are suitable for use when retention of acid-labile side-chain protecting groups is required. This technique may be adaptable to a variety of unnatural amino acid substrates. https://www.jove.com/v/55677 404 2017-04-06T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60442.jpg Synthesis of Information-bearing Peptoids and their Sequence-directed Dynamic Covalent Self-assembly A protocol is presented for the synthesis of information-encoded peptoid oligomers and for the sequence-directed self-assembly of these peptoids into molecular ladders using amines and aldehydes as dynamic covalent reactant pairs and Lewis acidic rare-earth metal triflates as multi-role reagents. https://www.jove.com/v/60442 574 2020-02-06T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66605.jpg Synthesizing Amino Acids Modified with Reactive Carbonyls in Silico to Assess Structural Effects Using Molecular Dynamics Simulations Here, we describe a protocol for the optimization and parameterization of amino acid residues modified with reactive carbonyl species, adaptable to protein systems. The protocol steps include structure design and optimization, charge assignments, parameter construction, and preparation of protein systems. https://www.jove.com/v/66605 357 2024-04-26T21:30:00+00:00 JoVE no https://visualize.jove.com/18952433-implementation-of-a-multimodal-infection-control-program-during-an-acinetobacter-outbreak monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13229.jpg Infection When a pathogen enters the body and reproduces, it can cause an infection, damage body cells, and cause illness symptoms that eventually lead to disease. Therefore, its prevention requires breaking the chain of infection. The chain begins with pathogens: bacteria, viruses, fungi, prions, or parasites such as protozoa helminths. These can be present on the skin as transient or resident flora, or they can be acquired from the environment. Identifying and treating the type of infection and... https://www.jove.com/v/13229 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13237.jpg Healthcare Associated Infections II: Preventive Measures Essential infection prevention measures are based on the knowledge of the infection chain, the modes of transmission in healthcare settings, and the use of the best practices in all healthcare settings. Compulsory public reporting of healthcare-associated infection rates is needed to allow individuals and the community to make informed choices regarding selecting a healthcare facility. The best practices for preventing healthcare-associated infections include hand hygiene, patient risk... https://www.jove.com/v/13237 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13245.jpg Transmission-based Precautions II: Airborne and Protective Environment Transmission-based precautions are for patients infected or suspected to be infected (or colonized) with organisms posing a significant risk to others. The transmission precautions include airborne and protective environment precautions. Airborne precautions: Use airborne precautions when treating patients known or suspected to have diseases that spread through the air—for example, tuberculosis or measles. These organisms are present in smaller droplets expelled by an infected person and... https://www.jove.com/v/13245 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13249.jpg Standard Precaution Standard precautions are the minimum infection control safeguards used while caring for all patients, irrespective of their disease condition. They help prevent the spread of common infectious microorganisms to healthcare workers, patients, and visitors in all healthcare settings. Hand hygiene is the most crucial means to prevent the transmission of disease. Employers are legally required to provide their workers with personal protective equipment (PPE) to minimize exposure or contact with... https://www.jove.com/v/13249 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/19522/19522_article_thumb_19522.jpg Antimicrobial Effectiveness The effectiveness of antimicrobial agents depends on various factors influencing their ability to eliminate microbial populations. Larger microbial populations require more time for complete eradication, emphasizing the importance of population size analysis when evaluating antimicrobial efficacy.Microbial resistance to antimicrobial agents varies significantly. Highly resilient microorganisms include endospores, gram-negative bacteria, and non-enveloped viruses, while prions are exceptionally... https://www.jove.com/v/19522 88 2025-06-12T16:43:38+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40814/40814_article_thumb_40814.jpg Investigation of Disease Outbreaks Multistate foodborne outbreaks pose significant public health risks and require meticulous investigation to identify sources and implement control measures. The Centers for Disease Control and Prevention (CDC) utilizes a dynamic seven-step process for these investigations, integrating data from laboratories, interviews, and environmental assessments to protect public health.Outbreak Detection: The detection of multistate outbreaks typically begins with PulseNet, the CDC's national laboratory... https://www.jove.com/v/40814 83 2026-03-12T20:35:44+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65517.jpg Quantification, Viability Assessment, and Visualization Strategies for Acinetobacter Biofilms This protocol describes the preparation of the inoculum, the biofilm quantification on microtiter plates using crystal violet dye, the viable count in biofilms, and the visualization of biofilms of Acinetobacter. https://www.jove.com/v/65517 461 2023-08-04T21:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67542.jpg Rapid and Specific Detection of Acinetobacter baumannii Infections Using a Recombinase Polymerase Amplification/Cas12a-based System To facilitate the rapid and precise detection of Acinetobacter baumannii, we present a protocol that employs Recombinase Polymerase Amplification (RPA) in conjunction with LbaCas12a endonuclease for identifying A. baumannii infections. https://www.jove.com/v/67542 479 2025-04-25T20:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/69913.jpg Automated Hospital Room Disinfection Utilizing a Novel Aerosolized Hydrogen Peroxide Microdroplet Disbursing Technology This protocol describes the methods for using a novel dry aerosolized hydrogen peroxide (aHP) fogging disinfection technology that provides smart-hospital connectivity, allowing integration within data platforms to provide historical data on equipment usage, verification of aHP dosages, room coverage, disinfection times, and locations to reduce healthcare-associated infections (HAIs). https://www.jove.com/v/69913 387 2026-02-24T22:30:00+00:00 JoVE no https://visualize.jove.com/18974798-a-formal-ontology-of-subcellular-neuroanatomy monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10842.jpg Neuron Structure Overview Neurons are the main type of cell in the nervous system that generate and transmit electrochemical signals. They primarily communicate with each other using neurotransmitters at specific junctions called synapses. Neurons come in many shapes that often relate to their function, but most share three main structures: an axon and dendrites that extend out from a cell body. Structure and Function of Neurons The neuronal cell body—the soma— houses the nucleus and organelles vital to... https://www.jove.com/v/10842 91 2025-10-23T18:49:29+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11593.jpg Additional Subnuclear Structures The eukaryotic nucleus is a double membrane-bound organelle that contains nearly all of the cell’s genetic material in the form of chromosomes. It is rightly called the “brain” of the cell as it shoulders the responsibility of responding to various physiological processes, stress, altered metabolic conditions, and other cellular signals. The nucleus contains many membrane-less subnuclear organelles or nuclear bodies, such as nucleoli, Cajal bodies, speckles, paraspeckles, etc. These nuclear... https://www.jove.com/v/11593 130 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12175.jpg Neuron Structure Neurons are the main type of cell in the nervous system that generate and transmit electrochemical signals. They primarily communicate with each other using neurotransmitters at specific junctions called synapses. Neurons come in many shapes that often relate to their function, but most share three main structures: an axon and dendrites that extend out from a cell body. Structure and Function of Neurons The neuronal cell body—the soma— houses the nucleus and organelles vital to cellular... https://www.jove.com/v/12175 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13848.jpg Structural Organization of the Human Body: An Overview It is convenient to consider the body's structures in terms of fundamental levels of organization that increase in complexity: subatomic particles, atoms, molecules, organelles, cells, tissues, organs, organ systems, and organisms. To study the chemical level of organization, scientists consider the simplest building blocks of matter: subatomic particles, atoms, and molecules. All matter in the universe is composed of one or more unique pure substances called elements, familiar examples of... https://www.jove.com/v/13848 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14882.jpg Organization of the Nervous System The nervous system is one of the most complex systems in our body. It is organized into two main divisions: the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS, comprising the brain and spinal cord, houses billions of neurons. The brain is housed in the skull, while the spinal cord is linked to the brain through the foramen magnum of the occipital bone and is surrounded by the protective structure of the vertebral column. It is responsible for processing various... https://www.jove.com/v/14882 73 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17746.jpg Organization of the Brain The brain is an integral component of the nervous system and serves as the center for processing sensory inputs, making decisions, and directing bodily actions. This complex organ is organized into three primary sections: the hindbrain, midbrain, and forebrain, each responsible for a range of vital functions. Hindbrain The hindbrain, located at the base of the brain, plays a vital role in regulating automatic processes that sustain life. It includes the medulla oblongata, which is essential for... https://www.jove.com/v/17746 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58027.jpg Large-scale Three-dimensional Imaging of Cellular Organization in the Mouse Neocortex Here we describe a procedure for tissue clearing, fluorescent labeling, and large-scale imaging of mouse brain tissue which, thereby, enables visualization of the three-dimensional organization of cell types in the neocortex. https://www.jove.com/v/58027 595 2018-09-05T22:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61847.jpg Array Tomography Workflow for the Targeted Acquisition of Volume Information using Scanning Electron Microscopy We describe the preparation of ribbons of serial sections and their collection on large transfer support for use as Array Tomography samples, along with automated imaging procedures in a scanning electron microscope. The protocol allows screening, retrieval, and targeted imaging of local, rare events, and the acquisition of large data volumes. https://www.jove.com/v/61847 587 2021-07-15T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61941.jpg Microdissection of Mouse Brain into Functionally and Anatomically Different Regions We present a hands-on, step-by-step, rapid protocol for mouse brain removal and dissection of discrete regions from fresh brain tissue. Obtaining brain regions for molecular analysis has become routine in many neuroscience labs. These brain regions are immediately frozen to obtain high quality transcriptomic data for system level analysis. https://www.jove.com/v/61941 486 2021-02-15T20:30:00+00:00 JoVE no https://visualize.jove.com/19010979-extracorporeal-pumpless-interventional-lung-assist-in-clinical-practice-determinants-of-efficacy monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/62982.jpg Normothermic Negative Pressure Ventilation Ex Situ Lung Perfusion: Evaluation of Lung Function and Metabolism This paper describes a porcine model of negative pressure ventilation ex situ lung perfusion, including procurement, attachment, and management on the custom-made platform. Focus is made on anesthetic and surgical techniques, as well as... https://app.jove.com/v/62982 571 2700 2022-02-14T06:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65981.jpg Establishment of an Ex Vivo Lung Perfusion Rat Model for Translational Insights in Lung Transplantation Here, we describe the necessary steps for establishing a rat EVLP model and show the inflammatory profile associated with the perfused lungs. The aim is to propagate knowledge and experiences about the rat EVLP model, enabling the integral understanding of the biological responses associated with that revolutionary... https://app.jove.com/v/65981 349 1200 2023-09-29T06:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67168.jpg Establishment of a Novel Ex Vivo Lung Perfusion System for Rat Lungs After Circulatory Death The objective is to develop a new ex vivo lung perfusion (EVLP) model in rats that can sustain consistent lung function for 4 h throughout EVLP and furnish the industry with implementation specifics that will offer a sturdy method for applying EVLP to rodent models. https://app.jove.com/v/67168 554 1300 2024-10-18T06:10:00+00:00 JoVE no https://visualize.jove.com/19028691-the-rna-activated-protein-kinase-enhances-the-induction-of-interferon-beta-and-apoptosis-mediated-by-cytoplasmic-rna-sensors monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10804.jpg RNA Interference RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated. This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used... https://www.jove.com/v/10804 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10804.jpg RNA Interference RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated. This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used... https://www.jove.com/v/11627 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11629.jpg siRNA - Small Interfering RNAs Small interfering RNAs, or siRNAs, are short regulatory RNA molecules that can silence genes post-transcriptionally, as well as the transcriptional level in some cases. siRNAs are important for protecting cells against viral infections and silencing transposable genetic elements. In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the ATP-dependent... https://www.jove.com/v/11629 150 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12033.jpg Experimental RNAi RNA interference (RNAi) is a cellular mechanism that inhibits gene expression by suppressing its transcription or activating the RNA degradation process. The mechanism was discovered by Andrew Fire and Craig Mello in 1998 in plants. Today, it is observed in almost all eukaryotes, including protozoa, flies, nematodes, insects, parasites, and mammals. This precise cellular mechanism of gene silencing has been developed into a technique that provides an efficient way to identify and determine the... https://www.jove.com/v/12033 135 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12249.jpg Regulation of the Unfolded Protein Response Inositol-requiring kinase one or IRE1 is the most conserved eukaryotic unfolded protein response (UPR) receptor. It is a type I transmembrane protein kinase receptor with a distinctive site-specific RNase activity. As the binding mechanics of the misfolded proteins with the N-terminal domain of IRE-1 are unclear, three binding models — direct, indirect, and allosteric -- are proposed for receptor activation. Nevertheless, it is known that once a misfolded protein associates with IRE1, it... https://www.jove.com/v/12249 91 JoVE no https://cloudfront.jove.com/files/ftp_upload/40862/40862_article_thumb_40862.jpg Inhibitors of Viral Protein Synthesis Protein synthesis is indispensable for viral replication, as viruses lack the cellular machinery required for this process and must hijack the host's translational apparatus. In response, host cells deploy a critical innate immune defense involving interferons, specialized cytokines that play a central role in inhibiting viral propagation.Upon viral detection, infected cells release interferons that bind to receptors on adjacent uninfected cells, activating the JAK-STAT signaling pathway and... https://www.jove.com/v/40862 90 2026-03-12T20:36:03+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51415.jpg Monitoring Activation of the Antiviral Pattern Recognition Receptors RIG-I And PKR By Limited Protease Digestion and Native PAGE Innate defenses to virus infections are triggered by pattern recognition receptors (PRRs). The two cytoplasmic PRRs RIG-I and PKR bind to viral signature RNAs, change conformation, oligomerize, and activate antiviral signaling. Methods are described which allow to conveniently monitor the conformational switching and the oligomerization of these cytoplasmic PRRs. https://www.jove.com/v/51415 763 2014-07-29T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53723.jpg A High Resolution Method to Monitor Phosphorylation-dependent Activation of IRF3 Here we describe a procedure allowing a detailed analysis of the phosphorylation-dependent activation of the IRF3 transcription factor. This is achieved through the combination of a high resolution SDS-PAGE and a native-PAGE coupled to immunoblots using multiple phosphospecific antibodies. https://www.jove.com/v/53723 704 2016-01-24T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59215.jpg Studying RNA Interactors of Protein Kinase RNA-Activated during the Mammalian Cell Cycle We present experimental approaches for studying RNA-interactors of double-stranded RNA binding protein kinase RNA-activated (PKR) during the mammalian cell cycle using HeLa cells. This method utilizes formaldehyde to crosslink RNA-PKR complexes and immunoprecipitation to enrich PKR-bound RNAs. These RNAs can be further analyzed through high-throughput sequencing or qRT-PCR. https://www.jove.com/v/59215 605 2019-03-05T22:00:00+00:00 JoVE no https://visualize.jove.com/19163432-evaluation-of-cortical-visual-prostheses-microelectrode-array-function-description-of-behavioral-feline-model monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/50872.jpg Functional Imaging of Auditory Cortex in Adult Cats using High-field fMRI Functional studies of the auditory system in mammals have traditionally been conducted using spatially-focused techniques such as electrophysiological recordings. The following protocol describes a method of visualizing large-scale patterns of evoked hemodynamic activity in the cat auditory cortex using functional magnetic resonance imaging. https://www.jove.com/v/50872 650 2014-02-19T22:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60600.jpg Monocular Visual Deprivation and Ocular Dominance Plasticity Measurement in the Mouse Primary Visual Cortex Here, we present detailed protocols for monocular visual deprivation and ocular dominance plasticity analysis, which are important methods for studying the neural mechanisms of visual plasticity during the critical period and the effects of specific genes on visual development. https://www.jove.com/v/60600 522 2020-02-08T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66867.jpg The DREAM Implant: A Lightweight, Modular, and Cost-Effective Implant System for Chronic Electrophysiology in Head-Fixed and Freely Behaving Mice Here, we introduce a lightweight, cost-effective probe implant system for chronic electrophysiology in rodents optimized for ease of use, probe recovery, experimental versatility, and compatibility with behavior. https://www.jove.com/v/66867 522 2024-07-26T21:10:00+00:00 JoVE no https://visualize.jove.com/19163667-control-strategies-for-smart-prosthetic-hand-technology-an-overview monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/52968.jpg A Structured Rehabilitation Protocol for Improved Multifunctional Prosthetic Control: A Case Study As prosthetic development moves towards the goal of natural control, harnessing amputees’ inherent ability to learn new motor skills may enable proficiency. This manuscript describes a structured rehabilitation protocol, which includes imitation, repetition, and reinforcement learning strategies, for improved multifunctional prosthetic control. https://www.jove.com/v/52968 418 2015-11-07T00:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55705.jpg The Bionic Clicker Mark I & II A device was created to demonstrate electromyography-based control to a lay audience. After the success of the initial device, a second device was made with greater flexibility in functionality for demonstration and research purposes. This protocol describes the process of building and calibrating both devices. https://www.jove.com/v/55705 503 2017-08-14T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65917.jpg A Flexible Wearable Supernumerary Robotic Limb for Chronic Stroke Patients This protocol introduces a flexible wearable supernumerary robotic limb tailored to assist in finger rehabilitation for stroke patients. The design incorporates a bending sensor to facilitate seamless human-robot interaction. Validation through experiments involving both healthy volunteers and stroke patients underscores the efficacy and dependability of the proposed study. https://www.jove.com/v/65917 235 2023-10-27T20:40:00+00:00 JoVE no https://visualize.jove.com/19163763-probabilistic-assessment-of-autonomic-nervous-system-fluctuations-during-tilt-table-tests monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2502.jpg Quantitative Autonomic Testing Standardized, comprehensive and fully quantitative testing of autonomic functions is described. The autonomic tests consist of evaluation of all three major autonomic domains including cardiovagal, adrenergic and sudomotor. The severity and distribution of dysautonomia is quantitated using Composite Autonomic Severity Scores. https://www.jove.com/v/2502 700 2011-07-19T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/4315.jpg Tilt Testing with Combined Lower Body Negative Pressure: a "Gold Standard" for Measuring Orthostatic Tolerance We describe a "gold standard" for evaluating orthostatic tolerance (OT) using tilt testing with combined lower body negative pressure (LBNP). This can be combined with non-invasive evaluations of cardiovascular reflex control. Normal and abnormal responses are defined. https://www.jove.com/v/4315 849 2013-03-21T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58611.jpg A Vibrotactile Feedback Device for Seated Balance Assessment and Training A sitting platform has been developed and assembled that passively destabilizes sitting posture in humans. During the user's stabilizing task, an inertial measurement unit records the device's motion, and vibrating elements deliver performance-based feedback to the seat. The portable, versatile device may be used in rehabilitation, assessment, and training paradigms. https://www.jove.com/v/58611 553 2019-01-20T21:30:00+00:00 JoVE no https://visualize.jove.com/19164579-altered-temporal-correlations-in-parietal-alpha-and-prefrontal-theta-oscillations-in-early-stage-alzheimer-disease monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2715.jpg Examining the Characteristics of Episodic Memory using Event-related Potentials in Patients with Alzheimer's Disease The methodology for collecting high-density event-related potential data while patients with Alzheimer's disease perform a recognition memory task is reviewed. This protocol will include subject preparation, quality assurance, data acquisition, and data analysis. https://www.jove.com/v/2715 661 2011-08-30T20:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15204.jpg Alzheimer's Disease: Overview Alzheimer's Disease (AD) is a continually advancing neurodegenerative disorder, distinguished by escalating memory loss, cognitive dysfunction, and dementia. The disease unfolds in three stages: preclinical, mild cognitive impairment (MCI), and dementia. Its onset is insidious, and the progression gradual, with the cause not well explained by other disorders. The clinical diagnosis of AD hinges on the presence of memory and other cognitive impairments. Biomarkers, such as changes in Aβ and tau... https://www.jove.com/v/15204 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/40940/40940_article_thumb_40940.jpg Alzheimer Disease l: Introduction Alzheimer disease is a chronic, progressive, and irreversible neurodegenerative disorder and the most common cause of dementia in older adults. It leads to gradual neuronal loss, causing cognitive decline, behavioral changes, and loss of functional independence.Risk Factors and EtiologyThe disease is multifactorial. Age is the strongest risk factor, with prevalence doubling every 5 years after age 65. Genetic factors include mutations in genes such as APP, PSEN1, and PSEN2, which are associated... https://www.jove.com/v/40940 89 2026-04-15T17:31:37+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40941/40941_article_thumb_40941.jpg Alzheimer Disease ll: Pathophysiology Alzheimer disease involves structural changes in the brain that begin long before symptoms appear. The most distinctive features are extracellular neuritic plaques and intracellular neurofibrillary tangles.Neuritic plaques form in the cerebral cortex and around blood vessels. These plaques contain a dense core of beta-amyloid (Aβ)—a toxic protein fragment that clumps outside neurons. The core is surrounded by damaged neuronal extensions, as well as reactive astrocytes and microglia. Abnormal... https://www.jove.com/v/40941 83 2026-04-13T21:37:54+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40948/40948_article_thumb_40948.jpg Dementia l: Introduction Dementia is an acquired, progressive syndrome characterized by a decline in multiple cognitive domains severe enough to impair daily functioning and reduce independence. Although memory loss is a central feature, the diagnosis requires additional deficits involving language, executive function, visuospatial skills, judgment, calculation, or abstract reasoning. These cognitive impairments reflect underlying neurodegenerative or vascular processes that gradually disrupt neuronal networks... https://www.jove.com/v/40948 82 2026-04-13T23:55:59+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58839.jpg Disruption of Frontal Lobe Neural Synchrony During Cognitive Control by Alcohol Intoxication This experiment uses an anatomically-constrained magnetoencephalography (aMEG) method to examine brain oscillatory dynamics and long-range functional synchrony during engagement of cognitive control as a function of acute alcohol intoxication. https://www.jove.com/v/58839 566 2019-02-06T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59310.jpg Evaluation of Hemisphere Lateralization with Bilateral Local Field Potential Recording in Secondary Motor Cortex of Mice We present in vivo electrophysiological recording of the local field potential (LFP) in bilateral secondary motor cortex (M2) of mice, which can be applied to evaluate hemisphere lateralization. The study revealed altered levels of synchronization between the left and right M2 in APP/PS1 mice compared to WT controls. https://www.jove.com/v/59310 423 2019-07-31T19:30:00+00:00 JoVE no https://visualize.jove.com/19198817-haptic-localizations-for-onset-and-offset-of-vibro-tactile-stimuli-are-dissociated monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10859.jpg Somatosensation The somatosensory system relays sensory information from the skin, mucous membranes, limbs, and joints. Somatosensation is more familiarly known as the sense of touch. A typical somatosensory pathway includes three types of long neurons: primary, secondary, and tertiary. Primary neurons have cell bodies located near the spinal cord in groups of neurons called dorsal root ganglia. The sensory neurons of ganglia innervate designated areas of skin called dermatomes. In the skin, specialized... https://www.jove.com/v/10859 93 2025-10-23T18:49:22+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14499.jpg Local Anesthetics: Differential Sensitivity of Nerve Fibers Local anesthetics (LAs) block the sodium channels of nerve trunks, sensory nerve endings, and neuromuscular junctions. Although LAs can block all kinds of nerves, the sensitivity of nerve fibers differs according to nerve types and structures. LAs are known to block myelinated fibers faster than unmyelinated ones. Also, they block pain or sensory neurons at low concentrations without affecting the motor neurons involved in muscle contractions. This helps relieve labor pain without affecting the... https://www.jove.com/v/14499 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14933.jpg Sensory Perception: Organization of the Somatosensory System The somatosensory system is the central and peripheral nervous system component that senses and processes touch, pressure, pain, temperature, and body position or proprioception. The process of sensation takes place at three levels: The receptor level: The receptor level is the first stage of sensation. It involves the detection of a stimulus by specialized sensory receptors. The stimulus must arrive within the receptor's receptive field. Next, the receptor converts the energy of the stimulus... https://www.jove.com/v/14933 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14935.jpg Major Somatic Sensory Pathways Sensory impulses related to touch, pressure, vibration, and proprioception from various body parts, such as the limbs, trunk, neck, and posterior head, travel to the cerebral cortex through the posterior column-medial lemniscus pathway. The pathway’s name derives from the two white-matter tracts that convey the impulses: the spinal cord's posterior column and the brainstem's medial lemniscus. First-order sensory neurons extend their axons into the spinal cord, forming the posterior columns... https://www.jove.com/v/14935 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17749.jpg Somatosensory, Motor, and Association Cortex The somatosensory cortex in the parietal lobes is crucial for interpreting sensory data such as touch, temperature, and proprioception. The somatosensory cortex, situated in the parietal lobes, plays a vital role in interpreting sensory information like touch, temperature, and proprioception—awareness of body position. This specialized brain region features an organized structure wherein neurons at the top primarily process sensations originating from the lower body. In contrast, those at the... https://www.jove.com/v/17749 83 2026-03-20T20:23:54+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17773.jpg Tactile and Chemical Senses Tactile senses encompass touch, temperature, and pain, each mediated by specific receptors. Touch receptors detect mechanical energy or pressure against the skin. Sensory fibers from these receptors enter the spinal cord and relay information to the brain stem. Here, most fibers cross over to the opposite side of the brain. The touch information then moves to the thalamus, which projects a map of the body's surface onto the somatosensory areas of the parietal lobes in the cerebral cortex. This... https://www.jove.com/v/17773 87 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52966.jpg Measurement of Vibration Detection Threshold and Tactile Spatial Acuity in Human Subjects Here, we present protocols to determine vibration detection thresholds and tactile acuity using psychophysical methods in... https://www.jove.com/v/52966 452 13000 2016-09-01T12:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53733.jpg Testing Tactile Masking between the Forearms Here we explore contralateral tactile masking between the forearms in which tactile detection thresholds are modulated by vibration applied to a remote site. The details of which remote sites have an effect can tell us about how the body is represented in the brain. https://www.jove.com/v/53733 485 6700 2016-02-10T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59493.jpg Applying Incongruent Visual-Tactile Stimuli during Object Transfer with Vibro-Tactile Feedback We present a protocol to apply incongruent visual-tactile stimuli during an object transfer task. Specifically, during block transfers, performed while the hand is hidden, a virtual presentation of the block shows random occurrences of false block drops. The protocol also describes adding vibrotactile feedback while performing the motor... https://www.jove.com/v/59493 343 5800 2019-05-23T13:30:00+00:00 JoVE no https://visualize.jove.com/19396369-functional-models-for-large-scale-gene-regulation-networks-realism-and-fiction monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11525.jpg Protein Networks An organism can have thousands of different proteins, and these proteins must cooperate to ensure the health of an organism. Proteins bind to other proteins and form complexes to carry out their functions. Many proteins interact with multiple other proteins creating a complex network of protein interactions. These interactions can be represented through maps depicting protein-protein interaction networks, represented as nodes and edges. Nodes are circles that are representative of a protein,... https://www.jove.com/v/11525 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11525.jpg Protein Networks An organism can have thousands of different proteins, and these proteins must cooperate to ensure the health of an organism. Proteins bind to other proteins and form complexes to carry out their functions. Many proteins interact with multiple other proteins creating a complex network of protein interactions. These interactions can be represented through maps depicting protein-protein interaction networks, represented as nodes and edges. Nodes are circles that are representative of a protein,... https://www.jove.com/v/12507 146 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13181.jpg Structure of a Gene A gene is the fundamental unit of heredity. Every individual has two copies of each gene, one inherited from each parent. Although most people contain the same genes, there is a small fraction that is slightly different amongst people. A gene with a small difference in its sequence of DNA bases forms different alleles, contributing to different phenotypes. However, only 1% of the DNA is composed of genes that encode proteins; the rest, 99% is non-coding DNA. This non-coding DNA performs... https://www.jove.com/v/13181 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13949.jpg Regulation of Expression at Multiple Steps The gene expression in cells is regulated at different stages: (i) transcription, (ii) RNA processing, (iii) RNA localization, and (iv) translation. Transcriptional regulation is mediated by regulatory proteins such as transcription factors, activators, or repressors—these control gene expression by initiating or inhibiting the transcription of genes. Once a precursor or pre-mRNA is produced, it undergoes post-transcriptional modification, including 5' capping, splicing, and the addition of a... https://www.jove.com/v/13949 83 JoVE no https://cloudfront.jove.com/files/ftp_upload/19531/19531_article_thumb_19531.jpg Constitutive and Regulated Gene Expression Gene expression in prokaryotes is governed by constitutive and regulated systems, allowing cells to balance the production of essential proteins with adaptive responses to environmental changes.Constitutive Gene ExpressionConstitutive, or housekeeping, genes are continuously expressed as they encode proteins vital for fundamental cellular processes. These include enzymes for glycolysis, ribosomal components for protein synthesis, and proteins involved in DNA replication. Their constant... https://www.jove.com/v/19531 87 2025-06-12T16:13:56+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19532/19532_article_thumb_19532.jpg Operon Model The operon model represents a fundamental mechanism of gene regulation in prokaryotes, enabling coordinated expression of genes involved in related metabolic or functional pathways. Operons consist of structural genes, a promoter, and an operator, with transcription regulated by repressors, activators, and small effector molecules.Structure and Function of OperonsAn operon is a cluster of structural genes transcribed together under the control of a single promoter. The promoter region... https://www.jove.com/v/19532 83 2025-06-12T16:14:08+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59655.jpg A Multilayer Microfluidic Platform for the Conduction of Prolonged Cell-Free Gene Expression The fabrication process of a PDMS-based, multilayer, microfluidic device that allows in vitro transcription and translation (IVTT) reactions to be performed over prolonged periods is described. Furthermore, a comprehensive overview of the hardware and software required to automate and maintain these reactions for prolonged durations is provided. https://www.jove.com/v/59655 683 2019-10-06T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63084.jpg Inherent Dynamics Visualizer, an Interactive Application for Evaluating and Visualizing Outputs from a Gene Regulatory Network Inference Pipeline The Inherent Dynamics Visualizer is an interactive visualization package that connects to a gene regulatory network inference tool for enhanced, streamlined generation of functional network models. The visualizer can be used to make more informed decisions for parameterizing the inference tool, thus increasing confidence in the resulting models. https://www.jove.com/v/63084 644 2021-12-07T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64793.jpg Rapid Development of Cell State Identification Circuits with Poly-Transfection Complex genetic circuits are time-consuming to design, test, and optimize. To facilitate this process, mammalian cells are transfected in a way that allows the testing of multiple stoichiometries of circuit components in a single well. This protocol outlines the steps for experimental planning, transfection, and data analysis. https://www.jove.com/v/64793 561 2023-02-24T22:40:00+00:00 JoVE no https://visualize.jove.com/20561536-heightened-susceptibility-to-interference-in-an-animal-model-of-amnesia-impairment-in-encoding-storage-retrieval-or-all-three monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14944.jpg Higher Mental Functions of Brain: Learning and Memory Memory is one of the most vital higher mental functions of the brain. Memory is closely related to learning because it enables us to retain information and experiences from our past to use them in our present life. It also helps us to remember facts, events, and skills, such as riding a bike or swimming. There are two types of memory — declarative memory, which involves memorizing facts or events, and procedural memory, which enables us to remember how to do something like writing or playing an... https://www.jove.com/v/14944 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18186.jpg Role of Hippocampus in Memory The hippocampus, a critical brain structure, plays an essential role in memory processing, particularly in the formation and retrieval of memory. This small, seahorse-shaped region is located within the medial temporal lobe, with one hippocampus in each brain hemisphere. Experimental studies involving lesions in the hippocampi of rats have demonstrated significant impairments in tasks such as object recognition and maze navigation, indicating the hippocampus involvement in both recognition and... https://www.jove.com/v/18186 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18188.jpg Role of Neurotransmitters in Memory Neurotransmitters are integral to the brain's communication system, enabling neurons to transmit signals across synapses. This chemical exchange underpins various cognitive functions, including memory processes. The role of neurotransmitters in memory is multifaceted, influencing the encoding, consolidation, and retrieval of memories through their action on different neural circuits. Glutamate and Synaptic Plasticity Glutamate, the brain's main excitatory neurotransmitter, is critical for... https://www.jove.com/v/18188 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18189.jpg Forgetting Forgetting is an intrinsic aspect of human memory, characterized by the gradual loss or inaccessibility of information over time. Hermann Ebbinghaus, a pioneering psychologist, extensively studied this phenomenon and formulated the forgetting curve. This curve illustrates that memory loss occurs rapidly immediately after learning and then decelerates over time. Several mechanisms contribute to forgetting, including encoding failure, storage decay, retrieval failure, and interference. Encoding... https://www.jove.com/v/18189 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18190.jpg Interference and Decay Forgetting is a complex cognitive phenomenon influenced by several factors, among which interference and decay are particularly prominent. These processes explain why individuals often struggle to retrieve specific information from memory, leading to lapses in recall that can be observed in everyday situations. Interference occurs when competing memories hinder the retrieval of particular information. It can be classified into two types: proactive and retroactive interference. Proactive... https://www.jove.com/v/18190 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18196.jpg Amnesia Amnesia is a condition marked by long-term memory loss, which impairs the ability to recall past events or create new memories. The severity and duration of memory loss vary depending on the type and underlying cause. Amnesia is classified into two main types: retrograde and anterograde. Retrograde amnesia is marked by the loss of memories formed before the onset of the condition. Patients may recall distant past events but often forget those occurring shortly before the incident. Anterograde... https://www.jove.com/v/18196 73 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52667.jpg The Double-H Maze: A Robust Behavioral Test for Learning and Memory in Rodents The goal of this protocol is to investigate spatial cognition in rodents. The double-H water maze is a novel test, which is particularly useful to elucidate the different components of learning, consolidation and memory, as well as the interplay of memory systems. https://www.jove.com/v/52667 541 2015-07-08T05:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60751.jpg Assessment of Memory Function in Pilocarpine-induced Epileptic Mice This article presents experimental procedures for assessing memory impairments in pilocarpine-induced epileptic mice. This protocol can be used to study the pathophysiologic mechanisms of epilepsy-associated cognitive decline, which is one of the most common comorbidities in epilepsy. https://www.jove.com/v/60751 814 2020-06-04T06:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64592.jpg Assessing Changes in Synaptic Plasticity Using an Awake Closed-Head Injury Model of Mild Traumatic Brain Injury Here, it is demonstrated how an awake closed-head injury model can be used for examining the effects of repeated mild traumatic brain injury (r-mTBI) on synaptic plasticity in the hippocampus. The model replicates important features of r-mTBI in patients and is used in conjunction with in vitro electrophysiology. https://www.jove.com/v/64592 589 2023-01-20T04:55:00+00:00 JoVE no https://visualize.jove.com/21056812-deep-hypothermic-circulatory-arrest-for-thoracoabdominal-aortic-aneurysm-repair-in-a-patient-with-a-large-intracranial-anterior-communicating-artery-aneurysm monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17981/17981_article_thumb_17981.jpg Aneurysm III: Interprofessional Care Aneurysm management involves either conservative medical therapy or surgical intervention, depending on the size and symptoms of the aneurysm. Conservative management is generally reserved for smaller, asymptomatic aneurysms, while larger or symptomatic aneurysms often necessitate surgical repair.Conservative Medical TherapyFor small, asymptomatic aneurysms, particularly abdominal aortic aneurysms (AAA) less than 5.5 centimeters in diameter, conservative medical therapy is recommended. This... https://app.jove.com/v/17981 86 450 2025-06-19T16:19:25+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17982/17982_article_thumb_17982.jpg Aneurysm IV: Nursing Management Vigilant monitoring for aneurysm rupture is essential for patients undergoing aortic surgery.Preoperative Nursing ManagementContinuously monitor the patient for manifestations of aneurysm rupture, such as pallor, weakness, tachycardia, hypotension, abdominal, back, groin, or periumbilical pain, changes in consciousness, and a pulsating abdominal mass. Regularly assess the patient's peripheral pulses.Instruct the patient to consume a clear liquid diet the day before surgery and administer... https://app.jove.com/v/17982 82 582 2025-06-19T16:19:35+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63571.jpg Establishment of Deep Hypothermic Circulatory Arrest in Rats This protocol presents the establishment of deep hypothermic circulatory arrest in rats, which can be applied to investigate systemic inflammatory response syndrome, ischemia/reperfusion injury, oxidative stress, neuroinflammation, etc. https://app.jove.com/v/63571 519 3000 2022-12-16T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63975.jpg Lung Rapid Recovery Procurement Combined with Abdominal Normothermic Regional Perfusion in Controlled Donation after Circulatory Death The protocol combines a lung cooling rapid recovery technique with abdominal normothermic regional perfusion for abdominal graft procurement in controlled asystole donors, which is a safe and useful method to expand the donor... https://app.jove.com/v/63975 594 2500 2022-08-15T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68211.jpg Modified Octopus Technique for Thoracoabdominal Aortic Aneurysm This study describes a modified octopus technique for endovascular treatment of thoracoabdominal aortic aneurysms, demonstrating favorable clinical... https://app.jove.com/v/68211 296 649 2025-08-01T19:50:00+00:00 JoVE no https://visualize.jove.com/21119899-increasing-response-diversity-in-children-with-autism monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14430.jpg Dose-Response Relationship: Selectivity and Specificity Drugs exert their therapeutic effects by interacting with receptors, enzymes, or ion channels that are present throughout the human body. The strength and duration of the interaction between a drug and its target receptor are characterized by the selectivity and specificity of the drug. Selectivity refers to a drug's strong preference for its intended target over other targets. For instance, isoprenaline, a non-selective β-adrenergic agonist, interacts with both β1- and... https://app.jove.com/v/14430 85 10700 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15342.jpg Diversity of Antigen Receptors Antigen receptors are essential components of the immune system crucial in defending the body against foreign invaders. These receptors are present on the surface of B and T cells, enabling them to recognize antigens and mount an appropriate immune response. Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two... https://app.jove.com/v/15342 88 2100 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18626.jpg Operant Conditioning Intervention Operant conditioning serves as a foundational principle in therapeutic interventions aimed at modifying maladaptive behaviors. Central to this approach is the notion that behaviors, both adaptive and maladaptive, are learned through reinforcement. By analyzing the environmental factors that reinforce problematic behaviors, clinicians can design interventions to weaken these reinforcements and replace maladaptive behaviors with healthier alternatives. In operant conditioning, behaviors that are... https://app.jove.com/v/18626 84 659 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18627.jpg Modeling in Therapy Modeling, a key technique in therapy, uses observational learning to help clients acquire and practice new skills by watching therapists demonstrate desired behaviors. This approach, rooted in Albert Bandura's concept of vicarious learning, plays a significant role in therapeutic interventions for various psychological conditions, including social anxiety, ADHD, and depression. Participant Modeling Participant modeling involves therapists demonstrating calm and effective behaviors in... https://app.jove.com/v/18627 86 727 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/19610.jpg Autism Spectrum Disorder Autism spectrum disorder (ASD) is a neurodevelopmental condition marked by persistent deficits in social communication and interaction alongside restrictive and repetitive behaviors or interests. ASD is sometimes accompanied by intellectual impairment. These core symptoms manifest differently among individuals, ranging from mild to severe. The disorder's complexity extends beyond its clinical presentation, encompassing a diverse range of biological, cognitive, and sociocultural influences.<br... https://app.jove.com/v/19610 79 1800 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52677.jpg Testing Sensory and Multisensory Function in Children with Autism Spectrum Disorder We describe how to implement a battery of behavioral tasks to examine the processing and integration of sensory stimuli in children with ASD. The goal is to characterize individual differences in temporal processing of simple auditory and visual stimuli and relate these to higher order perceptual skills like speech... https://app.jove.com/v/52677 553 17300 2015-04-22T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55941.jpg A Familiarization Protocol Facilitates the Participation of Children with ASD in Electrophysiological Research Electrophysiological research is an important tool for identifying biomarkers of developmental disorders, including Autism Spectrum Disorders (ASD), but data collection in these populations remains challenging. This work presents a familiarization protocol to accompany research that includes electroencephalography (EEG) to improve the likelihood of collecting EEG data from children with... https://app.jove.com/v/55941 522 8900 2017-07-31T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58348.jpg An Electrophysiology Protocol to Measure Reward Anticipation and Processing in Children This protocol is designed to measure reward anticipation and processing in young children with and without autism. Specifically, the protocol is designed to study the neural correlates of reward during social and nonsocial conditions while controlling for reward between conditions. https://app.jove.com/v/58348 304 7400 2018-10-04T21:30:00+00:00 JoVE no https://visualize.jove.com/21224968-attitude-of-resident-doctors-towards-intensive-care-units-alarm-settings monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/58802.jpg Observational Study Protocol for Repeated Clinical Examination and Critical Care Ultrasonography Within the Simple Intensive Care Studies Structured protocols are necessary to provide answers on research questions in critically ill patients. The Simple Intensive Care Studies (SICS) provides an infrastructure for repeated measurements in critically ill patients including clinical examination, biochemical analysis and ultrasonography. SICS projects have specific focus but the structure is flexible to other investigations.<br... https://app.jove.com/v/58802 638 21000 2019-01-16T21:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61644.jpg Halogenated Agent Delivery in Porcine Model of Acute Respiratory Distress Syndrome via an Intensive Care Unit Type Device We describe a model of hydrochloric acid-induced acute respiratory distress syndrome (ARDS) in piglets receiving sedation with halogenated agents, isoflurane and sevoflurane, through a device used for inhaled intensive care sedation. This model can be used to investigate the biological mechanisms of halogenated agents on lung injury and... https://app.jove.com/v/61644 576 3300 2020-09-24T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63797.jpg An Educational Video Demonstration of How to Prone a Critically Ill Intubated Patient Proning a critically ill patient with severe acute respiratory distress syndrome (ARDS) is a complex but beneficial procedure. Excellent communication skills, team work, and multidisciplinary collaboration are critical for patient and staff safety. A standard procedure should be utilized when proning ventilated patients with tubes, drains, and vascular access... https://app.jove.com/v/63797 436 5400 2022-11-30T20:30:00+00:00 JoVE no https://visualize.jove.com/22703905-do-autism-spectrum-disorders-involve-a-generalized-object-categorization-and-identification-dysfunction monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17781.jpg Visual Agnosia Visual agnosia is a condition characterized by the inability to recognize visually presented objects despite having normal vision. For instance, a person with visual agnosia can describe the shape and color of an object but cannot identify or name it. This impairment does not affect their visual field, acuity, color vision, brightness discrimination, language, or memory. An example of this condition in a social setting is someone at a dinner party asking for "that silver thing with a round... https://app.jove.com/v/17781 72 2000 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18602.jpg Diagnostic and Statistical Manual of Mental Disorders (DSM) The Diagnostic and Statistical Manual of Mental Disorders (DSM) serves as the primary classification system for mental health disorders, providing standardized diagnostic criteria for clinicians and researchers. First published by the American Psychiatric Association (APA) in 1952, the DSM has undergone several revisions to reflect evolving psychiatric understanding. The fifth edition, DSM-5, released in 2013, introduced key updates that expanded diagnostic categories and modified diagnostic... https://app.jove.com/v/18602 87 2000 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18605.jpg Social Anxiety Disorder Social anxiety disorder, also known as social phobia, is characterized by an intense fear of social situations where one might face humiliation, rejection, embarrassment, or negative evaluation. This disorder leads individuals to avoid activities like casual conversations, public speaking, or seemingly simple tasks such as eating, signing documents, or swimming, in public settings. Its impact extends beyond discomfort, often significantly interfering with daily functioning and quality of life.<br... https://app.jove.com/v/18605 88 870 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18627.jpg Modeling in Therapy Modeling, a key technique in therapy, uses observational learning to help clients acquire and practice new skills by watching therapists demonstrate desired behaviors. This approach, rooted in Albert Bandura's concept of vicarious learning, plays a significant role in therapeutic interventions for various psychological conditions, including social anxiety, ADHD, and depression. Participant Modeling Participant modeling involves therapists demonstrating calm and effective behaviors in... https://app.jove.com/v/18627 86 823 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/19610.jpg Autism Spectrum Disorder Autism spectrum disorder (ASD) is a neurodevelopmental condition marked by persistent deficits in social communication and interaction alongside restrictive and repetitive behaviors or interests. ASD is sometimes accompanied by intellectual impairment. These core symptoms manifest differently among individuals, ranging from mild to severe. The disorder's complexity extends beyond its clinical presentation, encompassing a diverse range of biological, cognitive, and sociocultural influences.<br... https://app.jove.com/v/19610 79 2000 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/19612.jpg Oppositional Defiant Disorder A persistent pattern of angry or irritable mood, defiant behavior, or vindictiveness characterizes Oppositional Defiant Disorder (ODD). Symptoms must occur over at least six months, involve interactions with individuals beyond siblings, and meet specific diagnostic criteria to be clinically significant. The disorder affects emotional regulation, social interactions, and behavior, often manifesting early in life and influencing long-term development and functioning. Diagnostic Criteria and... https://app.jove.com/v/19612 90 1500 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52677.jpg Testing Sensory and Multisensory Function in Children with Autism Spectrum Disorder We describe how to implement a battery of behavioral tasks to examine the processing and integration of sensory stimuli in children with ASD. The goal is to characterize individual differences in temporal processing of simple auditory and visual stimuli and relate these to higher order perceptual skills like speech... https://app.jove.com/v/52677 553 16500 2015-04-22T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58694.jpg Comparing Eye-tracking Data of Children with High-functioning ASD, Comorbid ADHD, and of a Control Watching Social Videos This is a qualitative comparative case study analysis of eye-tracking data on the first moments of social video scenes as viewed by three participants: one with autism spectrum disorder, one with comorbid attention deficit-hyperactive disorder, and one neurotypical... https://app.jove.com/v/58694 332 8500 2018-12-07T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66649.jpg Author Spotlight: Exploring Autism Spectrum Disorder Symptoms in Fruit Flies — Genetic Models and Behavioral Tests Autism Spectrum Disorder (ASD) is associated with impaired social and communicative behavior and the emergence of repetitive behavior. For studying the interrelation between ASD genes and behavioral deficits in the Drosophila model, five behavioral paradigms are described in this paper for assaying social spacing, aggression, courtship, grooming, and habituation behavior. https://app.jove.com/v/66649 510 2700 2024-09-06T20:00:00+00:00 JoVE no https://visualize.jove.com/22795801-stochastic-behavior-analysis-of-complex-repairable-industrial-systems-utilizing-uncertain-data monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14511.jpg Propagation of Uncertainty from Random Error An experiment often consists of more than a single step. In this case, measurements at each step give rise to uncertainty. Because the measurements occur in successive steps, the uncertainty in one step necessarily contributes to that in the subsequent step. As we perform statistical analysis on these types of experiments, we must learn to account for the propagation of uncertainty from one step to the next. The propagation of uncertainty depends on the type of arithmetic operation performed on... https://app.jove.com/v/14511 59 2200 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14512.jpg Propagation of Uncertainty from Systematic Error The atomic mass of an element varies due to the relative ratio of its isotopes. A sample's relative proportion of oxygen isotopes influences its average atomic mass. For instance, if we were to measure the atomic mass of oxygen from a sample, the mass would be a weighted average of the isotopic masses of oxygen in that sample. Since a single sample is not likely to perfectly reflect the true atomic mass of oxygen for all the molecules of oxygen on Earth, the mass we obtain from this... https://app.jove.com/v/14512 70 1600 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15596.jpg Statically Indeterminate Problem Solving Statically indeterminate problems are those where statics alone can not determine the internal forces or reactions. Consider a structure comprising two cylindrical rods made of steel and brass. These rods are joined at point B and restrained by rigid supports at points A and C. Now, the reactions at points A and C and the deflection at point B are to be determined. This rod structure is classified as statically indeterminate as the structure has more supports than are necessary for maintaining... https://app.jove.com/v/15596 76 874 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16100.jpg State Space Representation The frequency-domain technique, commonly used in analyzing and designing feedback control systems, is effective for linear, time-invariant systems. However, it falls short when dealing with nonlinear, time-varying, and multiple-input multiple-output systems. The time-domain or state-space approach addresses these limitations by utilizing state variables to construct simultaneous, first-order differential equations, known as state equations, for an nth-order system. Consider an RLC circuit, a... https://app.jove.com/v/16100 87 722 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16170.jpg Multimachine Stability Multimachine stability analysis is crucial for understanding the dynamics and stability of power systems with multiple synchronous machines. The objective is to solve the swing equations for a network of M machines connected to an N-bus power system. In analyzing the system, the nodal equations represent the relationship between bus voltages, machine voltages, and machine currents. The nodal equation is given by: V is the N-vector of bus voltages, E is the M-vector of machine voltages, I is... https://app.jove.com/v/16170 85 625 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16585.jpg Mechanistic Models: Compartment Models in Individual and Population Analysis Mechanistic models are utilized in individual analysis using single-source data, but imperfections arise due to data collection errors, preventing perfect prediction of observed data. The mathematical equation involves known values (Xi), observed concentrations (Ci), measurement errors (εi), model parameters (ϕj), and the related function (ƒi) for i number of values. Different least-squares metrics quantify differences between predicted and observed values. The ordinary least... https://app.jove.com/v/16585 83 335 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53690.jpg Data Acquisition Protocol for Determining Embedded Sensitivity Functions The data acquisition procedure for determining embedded sensitivity functions is described. Data is acquired and representative results are shown for a residential scale wind turbine... https://app.jove.com/v/53690 466 6600 2016-04-20T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67576.jpg Surrogate Model Development for Digital Experiments in Welding This protocol outlines a general workflow for constructing an artificial neural network for welding simulation using datasets generated automatically through Python scripts with macro functions. The workflow is validated against a benchmark case involving single-pass, straight-line welding. The surrogate model's predictive accuracy shows a strong agreement with finite element... https://app.jove.com/v/67576 557 2100 2025-03-28T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68888.jpg Simulation of a Scaled Assembly Process with Collaboration of a Robotic Arm and Monitoring through a Vision System for Quality Control Here, we present a protocol for the simulation and monitoring of a scaled semi-automated assembly process, through the collaboration of a collaborative robot and verification via a computer vision system for quality... https://app.jove.com/v/68888 347 622 2025-08-29T21:45:00+00:00 JoVE no https://visualize.jove.com/23616903-cognitive-analysis-of-decision-support-for-antibiotic-ordering-in-a-neonatal-intensive-care-unit monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3368.jpg Assessment and Evaluation of the High Risk Neonate: The NICU Network Neurobehavioral Scale The NICU Network Neurobehavioral Scale (NNNS) was developed as an assessment for the at-risk infant. The purpose of this article is to describe the NNNS, provide video examples of the NNNS procedures and discuss the ways in which the exam has been... https://app.jove.com/v/3368 1155 90500 2014-08-25T05:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10807.jpg Antibiotic Selection of Plasmids Overview Researchers use antibiotic resistance genes to identify bacteria that possess a plasmid containing their gene of interest. Antibiotic resistance naturally occurs when a spontaneous DNA mutation creates changes in bacterial genes that eliminate antibiotic activity. Bacteria can share these new resistance genes with their offspring and other bacteria. The overuse and misuse of antibiotics have created a public health crisis, as resistant and multi-resistant bacteria continue to develop.<br... https://app.jove.com/v/10807 57 48900 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13528.jpg Patient-centered Care Patient-centered care involves delivering care beyond inpatient hospitalization. Reflective practice can enhance a patient-centered approach. Reflective practice is a process of reasoning that considers all aspects of the present situation, including practicalities, learning from personal practice, and consideration of patient needs. Patients appreciate care decisions made while considering their input. Involving the patient in their care provides the patient with a sense of contribution rather... https://app.jove.com/v/13528 73 3100 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13530.jpg Critical Thinking II Critical thinking is a cognitive process with several attributes. The attributes of critical thinking include the following: • Confidence: Confidence tends to grow with experience in recognizing strengths and limitations. One example is performing IV cannulations. • Independent thinking: Independent thinking is essential to improve and expand nursing practice. An example is selecting nursing interventions that are best for the patient. • Fairness: Fairness... https://app.jove.com/v/13530 85 5300 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13551.jpg Nursing Interventions II: Selecting and Classifying the Nursing Interventions Creating and executing a nursing diagnosis helps nurses plan care and guide patient, family, and community interventions. They are developed based on a patient's physical evaluation and support measuring the outcomes. It is not recommended to select random interventions throughout the planning process. Instead, consider the following six essential factors when choosing interventions: Characteristics of the nursing diagnosis Goals and expected outcomes Evidence basis (e.g., research or... https://app.jove.com/v/13551 89 3300 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14126.jpg Nursing Clinical Information System Nursing Clinical Information System (NCIS) A Nursing Clinical Information System (NCIS) is a specialized type of healthcare information system tailored to meet the unique needs of nursing practice. It incorporates the principles of nursing informatics to streamline information management and improve the quality of care delivery. Critical attributes of NCIS include: Efficient Information Management: NCIS is designed to manage patient information efficiently, making it easily accessible to... https://app.jove.com/v/14126 87 1300 JoVE no https://cloudfront.jove.com/files/ftp_upload/40816/40816_article_thumb_40816.jpg Automated Microbial Diagnostics Automated diagnostic analyzers have transformed clinical microbiology by providing rapid and reliable methods for pathogen identification and antibiotic susceptibility testing. Among these systems, the Vitek 2 is widely used because it automates the traditionally labor-intensive processes of microbial identification (ID) and antibiotic susceptibility testing (AST), delivering standardized and timely results that are essential for effective patient care.Microbial Identification with ID CardsThe... https://app.jove.com/v/40816 84 77 2026-03-12T05:35:56+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58148.jpg Multiplex Therapeutic Drug Monitoring by Isotope-dilution HPLC-MS/MS of Antibiotics in Critical Illnesses Here we present a tandem mass spectrometry-based protocol for the quantification of frequently used antibiotics in intensive care units, namely cefepime, meropenem, ciprofloxacin, moxifloxacin, linezolid, and... https://app.jove.com/v/58148 677 11600 2018-08-30T07:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65810.jpg Author Spotlight: Developing a Point-of-Care Hemoglobin Estimation Method for Anemia Management An accurate hemoglobin estimation method is lacking at the point of care and may hinder population-based programs for treating anemia. Therefore, we developed a point-of-care method based on pooled capillary blood and an auto-analyzer integrated into a custom software application to categorize the hemoglobin values into different grades of anemia. https://app.jove.com/v/65810 335 1900 2024-01-19T05:20:00+00:00 JoVE no https://visualize.jove.com/24456397-recognizing-an-object-from-the-sum-of-its-parts-an-intracranial-study-on-alpha-rhythms monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14942.jpg Brain Waves Brain waves are electrical signals generated by the neurons in the brain, which are regularly monitored to measure mental activities. Brain waves and their frequency ranges can be measured using an electroencephalogram or EEG. There are four main types of brain waves, each with distinct characteristics: • Alpha Waves – Alpha brain waves, between 8 and 13 Hz ( Hertz), occur when a person is relaxed with eyes closed. The alpha waves then disappear when one is concentrating on specific tasks. <br... https://www.jove.com/v/14942 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52773.jpg Investigating the Function of Deep Cortical and Subcortical Structures Using Stereotactic Electroencephalography: Lessons from the Anterior Cingulate Cortex Stereotactic Electroencephalography (SEEG) is an operative technique used in epilepsy surgery to help localize seizure foci. It also affords a unique opportunity to investigate brain function. Here we describe how SEEG can be used to investigate cognitive processes in human... https://www.jove.com/v/52773 540 12100 2015-04-15T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53466.jpg Combined Invasive Subcortical and Non-invasive Surface Neurophysiological Recordings for the Assessment of Cognitive and Emotional Functions in Humans The present protocol aims at assessing cognitive-emotional functions in the basal ganglia by simultaneous neurophysiological recording of local field potentials and non-invasive brain cortical activity (EEG). The procedure is exemplified by the use of paradigms involving speech stimuli with emotional connotation or the Flanker task involving cognitive control. https://www.jove.com/v/53466 505 10500 2016-05-19T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58187.jpg Analyzing Neural Activity and Connectivity Using Intracranial EEG Data with SPM Software We present two analytical protocols that can be used to analyze intracranial electroencephalography data using the Statistical Parametric Mapping (SPM) software: time-frequency statistical parametric mapping analysis for neural activity, and dynamic causal modeling of induced responses for intra- and inter-regional... https://www.jove.com/v/58187 410 8900 2018-10-30T13:30:00+00:00 JoVE no https://visualize.jove.com/25026388-artificial-neural-networks-an-overview-and-their-use-in-the-analysis-of-the-amphora-3-dataset monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14900.jpg Neural Circuits Neural circuits and neuronal pools are two of the main structures found in the nervous system. Neural circuits are networks of neurons that work together to carry out a specific task or process. They consist of interconnected neurons and glial cells, which provide structural and metabolic support. Neuronal pools are collections of nerve cells with similar functions and interact through chemical and electrical signals. These pools include both interneurons (the central neural circuit nodes that... https://www.jove.com/v/14900 85 2025-06-13T16:07:11+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65910.jpg Author Spotlight: Advancing Alzheimer's Research – Exploring Early Detection and Multi-Omics Approaches DeepOmicsAE is a workflow centered on the application of a deep learning method (i.e., an autoencoder) to reduce the dimensionality of multi-omics data, providing a foundation for predictive models and signaling modules representing multiple layers of omics... https://www.jove.com/v/65910 587 2000 2023-12-15T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66473.jpg Author Spotlight: Advancing Large-Scale Neural Dynamics Through HD-MEA Technology Here, we employ HD-MEA to delve into computational dynamics of large-scale neuronal ensembles, particularly in hippocampal, olfactory bulb circuits, and human neuronal networks. Capturing spatiotemporal activity, combined with computational tools, provides insights into neuronal ensemble complexity. The method enhances understanding of brain functions, potentially identifying biomarkers and treatments for neurological... https://www.jove.com/v/66473 584 4600 2024-03-08T14:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68668.jpg Decoding Natural Behavior from Neuroethological Embedding This protocol gives an integrated framework based on advanced computational neuroethological methods to understand brain coding in naturalistic... https://www.jove.com/v/68668 480 885 2025-10-03T13:40:00+00:00 JoVE no https://visualize.jove.com/25116446-clinical-utility-of-an-observation-and-response-chart-with-human-factors-design-characteristics-and-a-track-and-trigger-system-study-protocol-for-a-two-phase-multisite-multiple-methods-design monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17145/17145_article_thumb_17145.jpg Bioavailability Study Design: Single Versus Multiple Dose Studies Bioavailability studies are essential for understanding how a drug is absorbed, distributed, metabolized, and excreted in the body. These studies assess the extent and rate at which the active pharmaceutical agent becomes available at the site of action. The design of bioavailability studies can involve single-dose or multiple-dose regimens, each with distinct advantages and limitations.Single-dose studies are the preferred approach due to their simplicity and reduced drug exposure for... https://www.jove.com/v/17145 71 2025-10-03T07:00:42+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60336.jpg A System for Tracking the Dynamics of Social Preference Behavior in Small Rodents Described here is a novel automated experimental system that offers an alternative to the three-chamber test and also solves several caveats. This system supplies multiple behavioral parameters that enable rigorous analysis of small rodent behavioral dynamics during the social preference and social novelty preference... https://www.jove.com/v/60336 518 7000 2019-11-21T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61409.jpg Tracking Rats in Operant Conditioning Chambers Using a Versatile Homemade Video Camera and DeepLabCut This protocol describes how to build a small and versatile video camera, and how to use videos obtained from it to train a neural network to track the position of an animal inside operant conditioning chambers. This is a valuable complement to standard analyses of data logs obtained from operant conditioning... https://www.jove.com/v/61409 512 12500 2020-06-15T14:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63385.jpg An Open-Source, Fully Customizable 5-Choice Serial Reaction Time Task Toolbox for Automated Behavioral Training of Rodents The present protocol describes the development of an open-source 5-choice serial reaction time task toolbox for rodent animal models, using Arduino and related hardware and a versatile Matlab toolbox, including an optional script for automated behavioral training. The scripts are customizable and facilitate the implementation of different trial-and-test... https://www.jove.com/v/63385 579 6300 2022-01-19T14:45:00+00:00 JoVE no https://visualize.jove.com/25202700-liver-transplantation-in-a-patient-with-complex-anomaly-of-the-inferior-vena-cava monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4143.jpg Orthotopic Liver Transplantation in Rats We present an easy-to-establish revision of the classical two-cuff technique for orthotopic liver transplantation in... https://www.jove.com/v/4143 1105 32700 2012-07-01T14:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15317.jpg Veins of the Abdomen and Pelvis The human body is a complex system of interconnected parts, and the circulatory system plays a crucial role in maintaining overall health. One key component of this system is the inferior vena cava, a large vein responsible for returning blood from the abdominopelvic viscera and abdominal walls to the heart. The inferior vena cava is fed by numerous smaller veins. The lumbar veins, for instance, drain the posterior abdominal wall, emptying both directly into the inferior vena cava and into the... https://www.jove.com/v/15317 78 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56933.jpg A Rat Model of Orthotopic Liver Transplantation Using a Novel Magnetic Anastomosis Technique for Suprahepatic Vena Cava Reconstruction The reconstruction of the suprahepatic vena cava (SHVC) remains a difficult step in rat orthotopic liver transplantation. In this article, we show a step-by-step protocol for SHVC reconstruction in rats using a novel magnetic anastomosis technique. https://www.jove.com/v/56933 873 9600 2018-03-19T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64152.jpg Porcine Liver Transplantation Without Veno-Venous Bypass As an Extended Criteria Donor Model In this protocol, a model of porcine orthotopic liver transplantation after static cold storage of donor organs for 20 h without the use of a veno-venous bypass during engraftment is described. The approach uses a simplified surgical technique with minimization of the anhepatic phase and sophisticated volume and vasopressor... https://www.jove.com/v/64152 769 2900 2022-08-17T14:00:00+00:00 JoVE no https://visualize.jove.com/25464759-induced-synchronization-of-alpha-rhythm-in-the-time-intervals-between-the-visual-stimuli-at-different-degrees-of-set-flexibility monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14848.jpg Muscle Stimulation Frequency The contraction strength of muscles is regulated by motor neurons, which modulate the frequency of action potentials dispatched to the motor units based on the body's requirements. This process of varying the muscle stimulation frequency allows muscles to contract with a force that is precisely tailored to the needs of the moment, whether lifting a feather or a heavy box. Wave summation At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches... https://www.jove.com/v/14848 82 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57349.jpg Optogenetic Entrainment of Hippocampal Theta Oscillations in Behaving Mice We describe the use of optogenetics and electrophysiological recordings for selective manipulations of hippocampal theta oscillations (5-10 Hz) in behaving mice. The efficacy of the rhythm entrainment is monitored using local field potential. A combination of opto- and pharmacogenetic inhibition addresses the efferent readout of hippocampal... https://www.jove.com/v/57349 453 12500 2018-06-29T13:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58408.jpg A Two-interval Forced-choice Task for Multisensory Comparisons Psychophysics is essential for studying perception phenomena through sensory information. Here we present a protocol to perform a two-interval forced-choice task as implemented in a previous report on human psychophysics where participants estimated the duration of visual, auditory, or audiovisual intervals of aperiodic trains of... https://www.jove.com/v/58408 433 11600 2018-11-09T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59898.jpg A Method for Tracking the Time Evolution of Steady-State Evoked Potentials A protocol to assess the time evolution of the neural entrainment to external repetitive stimuli is presented. Steady-state recordings of the same experimental condition are acquired and averaged in the time-domain. The steady-state dynamics are analyzed by plotting the response amplitude as a function of time. https://www.jove.com/v/59898 723 9100 2019-05-25T15:00:00+00:00 JoVE no https://visualize.jove.com/25708378-review-of-information-and-communication-technology-devices-for-monitoring-functional-and-cognitive-decline-in-alzheimers-disease-clinical-trials monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15204.jpg Alzheimer's Disease: Overview Alzheimer's Disease (AD) is a continually advancing neurodegenerative disorder, distinguished by escalating memory loss, cognitive dysfunction, and dementia. The disease unfolds in three stages: preclinical, mild cognitive impairment (MCI), and dementia. Its onset is insidious, and the progression gradual, with the cause not well explained by other disorders. The clinical diagnosis of AD hinges on the presence of memory and other cognitive impairments. Biomarkers, such as changes in Aβ and tau... https://www.jove.com/v/15204 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15205.jpg Alzheimer's Disease: Treatment Alzheimer's Disease (AD), a neurodegenerative disorder, is pathologically identified by amyloid plaques and neurofibrillary tangles composed of tau protein. AD pharmacotherapy aims to manage cognitive symptoms, delay disease progression, and treat behavioral symptoms. The treatment is primarily symptomatic and palliative, with no definitive disease-modifying therapy available. Cholinesterase inhibitors, including donepezil (Aricept), rivastigmine (Exelon), and galantamine (Razadyne), are... https://www.jove.com/v/15205 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18197.jpg Dementia Dementia is a collective term for cognitive disorders primarily affecting memory, thinking, and reasoning. It is not a specific disease but a syndrome, with Alzheimer's disease being the most common cause, accounting for approximately 60-80% of cases. Other types include vascular dementia, Lewy body dementia, and frontotemporal dementia. Dementia affects millions worldwide, particularly older adults, though it is not a normal part of aging. The progression of dementia is generally gradual. https://www.jove.com/v/18197 90 JoVE no https://cloudfront.jove.com/files/ftp_upload/40940/40940_article_thumb_40940.jpg Alzheimer Disease l: Introduction Alzheimer disease is a chronic, progressive, and irreversible neurodegenerative disorder and the most common cause of dementia in older adults. It leads to gradual neuronal loss, causing cognitive decline, behavioral changes, and loss of functional independence.Risk Factors and EtiologyThe disease is multifactorial. Age is the strongest risk factor, with prevalence doubling every 5 years after age 65. Genetic factors include mutations in genes such as APP, PSEN1, and PSEN2, which are associated... https://www.jove.com/v/40940 89 2026-04-15T17:31:37+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40941/40941_article_thumb_40941.jpg Alzheimer Disease ll: Pathophysiology Alzheimer disease involves structural changes in the brain that begin long before symptoms appear. The most distinctive features are extracellular neuritic plaques and intracellular neurofibrillary tangles.Neuritic plaques form in the cerebral cortex and around blood vessels. These plaques contain a dense core of beta-amyloid (Aβ)—a toxic protein fragment that clumps outside neurons. The core is surrounded by damaged neuronal extensions, as well as reactive astrocytes and microglia. Abnormal... https://www.jove.com/v/40941 83 2026-04-13T21:37:54+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40948/40948_article_thumb_40948.jpg Dementia l: Introduction Dementia is an acquired, progressive syndrome characterized by a decline in multiple cognitive domains severe enough to impair daily functioning and reduce independence. Although memory loss is a central feature, the diagnosis requires additional deficits involving language, executive function, visuospatial skills, judgment, calculation, or abstract reasoning. These cognitive impairments reflect underlying neurodegenerative or vascular processes that gradually disrupt neuronal networks... https://www.jove.com/v/40948 82 2026-04-13T23:55:59+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59649.jpg A Machine Learning Approach to Design an Efficient Selective Screening of Mild Cognitive Impairment This methodology produces decision trees that target population groups more prone to suffering from mild cognitive impairment and are useful for cost-effective selective screening of the... https://www.jove.com/v/59649 738 8200 2020-01-11T12:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60330.jpg A Computerized Functional Skills Assessment and Training Program Targeting Technology Based Everyday Functional Skills This training protocol uses computerized training to teach technology-related everyday functional skills. These skills include financial skills, travel and transit, as well as medication... https://www.jove.com/v/60330 451 7600 2020-02-13T12:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67176.jpg Transcranial Pulse Stimulation for Alzheimer's Patients This article describes the procedure of transcranial pulse stimulation in patients with Alzheimer's disease. It discusses the indications, methodology, and future prospects in... https://www.jove.com/v/67176 368 2500 2025-04-04T12:30:00+00:00 JoVE no https://visualize.jove.com/25878307-computer-navigation-for-total-knee-arthroplasty-reduces-revision-rate-for-patients-less-than-sixty-five-years-of-age monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14074.jpg Knee Joint The knee joint is the most complicated joint in the body. It consists of three articulations– two tibiofemoral and one patellofemoral. As is characteristic of synovial joints, the knee joint has a thin articular capsule that partially surrounds this joint cavity. Additionally, several ligaments, muscles, and cartilaginous structures support the movement of the knee. A total of seven ligaments support the knee joint. The patellar ligament, which is also attached to the quadriceps femoris group... https://www.jove.com/v/14074 83 JoVE no https://cloudfront.jove.com/files/ftp_upload/17978/17978_article_thumb_17978.jpg Peripheral Artery Disease V: Postoperative Nursing Management During the postoperative period, it is crucial to focus on maintaining circulation, identifying and managing potential complications, and planning for discharge.Nursing AssessmentVital signs monitoring: Regularly monitor vital signs, including blood pressure, heart rate, respiratory rate, and temperature, to detect early signs of complications such as bleeding and infection.Circulation assessment: Monitor pulses, perform Doppler assessments, and check capillary refill, color, temperature, and... https://www.jove.com/v/17978 83 2025-06-19T16:18:49+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63654.jpg The Use of Mixed Reality in Custom-Made Revision Hip Arthroplasty: A First Case Report A complex revision hip arthroplasty was performed using a custom-made implant and mixed reality technology. According to the authors' knowledge, this is the first report of such procedure described in the literature.<br... https://www.jove.com/v/63654 465 4000 2022-08-04T12:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63806.jpg Augmented Reality Navigation-Guided Core Decompression for Osteonecrosis of Femoral Head Augmented reality technology was applied to core decompression for osteonecrosis of the femoral head to realize real-time visualization of this surgical procedure. This method can effectively improve the safety and precision of core... https://www.jove.com/v/63806 377 4400 2022-04-12T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63948.jpg The Transition to an Anterior-Based Muscle Sparing Approach Improves Early Postoperative Function but is Associated with a Learning Curve The anterior-based muscle-sparing approach for total hip arthroplasty (THA) is associated with a learning curve. However, the improved clinical outcome in the early post-operative phase makes the consideration to transition worthwhile. https://www.jove.com/v/63948 591 3900 2022-09-07T12:30:00+00:00 JoVE no https://visualize.jove.com/25919084-hierarchical-flowerlike-gold-nanoparticles-labeled-immunochromatography-test-strip-for-highly-sensitive-detection-of-escherichia-coli-o157h7 monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13383.jpg Enzyme-Linked Immunosorbent Assay In 1971, Peter Perlman and Eva Engvall developed an Enzyme-linked immunosorbent assay (ELISA or EIA). ELISA differs from western blot in that the assays are conducted in microtiter plates or in vivo rather than on an absorbent membrane. There are many different types of ELISAs, but they all involve an antibody molecule whose constant region binds an enzyme, leaving the variable region free to bind its specific antigen. Enzyme-substrate reaction allows the antigen to be visualized or quantified. https://www.jove.com/v/13383 93 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13403.jpg Immunogold Electron Microscopy Immunoelectron microscopy utilizes immunogold labeling of endogenous proteins with specific antibodies to detect and localize these proteins in cells and tissues. The procedure provides insights into the distribution and quantification of protein under different stimulation conditions offering clues about their functions. Conjugating highly electron-dense gold particles with primary or secondary antibodies allow antigen detection on and within cells, with high resolution and specificity. https://www.jove.com/v/13403 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50967.jpg Detection of Live Escherichia coli O157:H7 Cells by PMA-qPCR A qPCR assay was developed for detection of Escherichia coli O157:H7 targeting a unique genetic marker, Z3276. The qPCR was combined with propidium monoazide (PMA) treatment for live cell detection. This protocol has been modified and adapted to a 96-well plate format for easy and consistent handling of numerous... https://www.jove.com/v/50967 496 17300 2014-02-01T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55821.jpg Foodborne Pathogen Screening Using Magneto-fluorescent Nanosensor: Rapid Detection of E. Coli O157:H7 The overall goal of this protocol is to synthesize functional nanosensors for the portable, cost-effective, and rapid detection of specifically targeted pathogenic bacteria through a combination of magnetic relaxation and fluorescence emission... https://www.jove.com/v/55821 544 8200 2017-09-17T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62754.jpg Development of a Lateral Flow Immunochromatographic Strip for Rapid and Quantitative Detection of Small Molecule Compounds Membrane-based lateral flow immunochromatographic strips (ICSs) are useful tools for low-cost self-diagnosis and have been efficiently applied to toxin, ... https://www.jove.com/v/62754 610 10100 2021-11-13T13:00:00+00:00 JoVE no https://visualize.jove.com/26320371-classification-of-cardiac-rhythm-using-heart-rate-dynamical-measures-validation-in-mit-bih-databases monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13286.jpg Pulse rhythm Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding. Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle... https://www.jove.com/v/13286 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15275.jpg Correlation between ECG and Cardiac Cycle The electrical signals recorded on an electrocardiogram (ECG) occur before the mechanical processes of contraction and relaxation during the cardiac cycle. A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before... https://www.jove.com/v/15275 85 2025-05-15T16:16:28+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17939/17939_article_thumb_17939.jpg Dysrhythmias II: Classification of Tachyarrhythmias Tachyarrhythmias are a type of dysrhythmia where the heart rate exceeds 100 beats per minute. Here are some common types of tachyarrhythmias:Sinus TachycardiaSinus tachycardia originates from increased impulses from the sinus node, leading to an elevated heart rate. It is often triggered by stress, fever, or exercise.Patients may experience palpitations, a sensation of a racing heart, dizziness, and chest discomfort.Causes and Risk Factors: Common causes include physical exertion, emotional... https://www.jove.com/v/17939 88 2025-06-19T16:35:48+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17940/17940_article_thumb_17940.jpg Dysrhythmias III: Characteristics of Dysrhythmias Dysrhythmias, also known as arrhythmias, are irregular heart rhythms that result from abnormal electrical activity in the heart, affecting its ability to circulate blood efficiently. Tachyarrhythmias, a subset of dysrhythmias, are characterized by abnormally fast heart rates exceeding 100 beats per minute. Here are some types of tachyarrhythmias with their distinct ECG features:Sinus Tachycardia:Sinus tachycardia presents a regular heart rhythm with an increased rate of 101-180 beats per minute. https://www.jove.com/v/17940 89 2025-06-19T16:36:05+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17941/17941_article_thumb_17941.jpg Dysrhythmias IV: Characteristics of Bradyarrhythmias Bradyarrhythmias are cardiac rhythm disorders characterized by a slower-than-normal heart rate, typically defined as fewer than 60 beats per minute. Some of which are discussed here:Sinus BradycardiaSinus bradycardia presents a heart rate lower than 60 beats per minute, with a regular rhythm originating from the SA node. The ECG typically shows normal P waves preceding each QRS complex, a normal PR interval (0.12 to 0.20 seconds), and a normal QRS duration (0.06 to 0.10 seconds).First-Degree AV... https://www.jove.com/v/17941 78 2025-06-19T16:36:24+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17942/17942_article_thumb_17942.jpg Dysrhythmias V: Evaluating Dysrhythmias Dysrhythmias, also known as arrhythmias, are disturbances in the heart's rhythm that range from benign to life-threatening. A thorough evaluation is crucial for appropriate management and involves a comprehensive medical history, physical examination, and various diagnostic tests.Medical HistorySymptoms: Collect detailed information on palpitations, dizziness, syncope, chest pain, and fatigue. Note their onset, frequency, and triggers.Previous Cardiac Issues: Document any history of heart... https://www.jove.com/v/17942 90 2025-06-19T16:36:46+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62386.jpg Analyzing Long-Term Electrocardiography Recordings to Detect Arrhythmias in Mice Here we present a step-by-step protocol for a semiautomated approach to analyze murine long-term electrocardiography (ECG) data for basic ECG parameters and common arrhythmias. Data are obtained by implantable telemetry transmitters in living and awake mice and analyzed using Ponemah and its analysis modules. https://www.jove.com/v/62386 367 2021-05-23T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65829.jpg BrainBeats as an Open-Source EEGLAB Plugin to Jointly Analyze EEG and Cardiovascular Signals The BrainBeats toolbox is an open-source EEGLAB plugin designed to jointly analyze EEG and cardiovascular (ECG/PPG) signals. It includes heartbeat-evoked potentials (HEP) assessment, feature-based analysis, and heart artifact extraction from EEG signals. The protocol will aid in studying brain-heart interplay through two lenses (HEP and features), enhancing reproducibility and accessibility. https://www.jove.com/v/65829 502 2024-04-26T19:40:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67222.jpg Software for Analysis of Heart Rate and Blood Pressure Time-series Data from the Valsalva Maneuver The ValsalvaAnalyzer software includes functions to analyze continuous beat-to-beat electrocardiogram and blood pressure (BP) measurements recorded during the Valsalva maneuver (VM). The computed clinical biomarkers and estimated model outputs provide insight into sympathetic and parasympathetic regulation of heart rate and BP during the VM. https://www.jove.com/v/67222 868 2025-06-27T19:40:00+00:00 JoVE no https://visualize.jove.com/26579032-ratio-dependence-in-small-number-discrimination-is-affected-by-the-experimental-procedure monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4375.jpg Perceptual and Category Processing of the Uncanny Valley Hypothesis' Dimension of Human Likeness: Some Methodological Issues Investigation of the Uncanny Valley Hypothesis and affective experience requires an understanding of the hypothesis' dimension of human likeness (DHL). This protocol allows representation of the DHL and examination of categorical perception. Use of the same stimuli and fMRI to distinguish brain regions responsive to physical and category change is... https://www.jove.com/v/4375 454 18100 2013-06-03T08:58:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17604.jpg Odds Ratio The odds ratio (OR) is a statistical measure used extensively in epidemiology and research to quantify the strength of association between exposure and outcome across different groups. Unlike relative risk, which compares the probabilities of an event occurring, the odds ratio compares the odds of an event occurring in the exposed group to the odds of it occurring in the unexposed group. The odds, in this context, are calculated as the probability of the event happening divided by the... https://www.jove.com/v/17604 69 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53503.jpg An Operant Intra-/Extra-dimensional Set-shift Task for Mice Attentional set-shifting cognitive abnormalities are a core feature of many psychiatric diseases. Here, we present the development of a novel automatic system for the effective study of attentional set-shifting abilities, executive functions and other cognitive abilities in mice with high translational validity to human... https://www.jove.com/v/53503 515 12900 2016-01-22T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63461.jpg A Psychophysics Paradigm for the Collection and Analysis of Similarity Judgments The protocol presents an experimental psychophysics paradigm to obtain large quantities of similarity judgments, and an accompanying analysis workflow. The paradigm probes context effects and enables modeling of similarity data in terms of Euclidean spaces of at least five... https://www.jove.com/v/63461 492 3000 2022-03-01T13:45:00+00:00 JoVE no https://visualize.jove.com/26587930-journal-club-radiology-report-addenda-a-self-report-approach-to-error-identification-quantification-and-classification monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13866.jpg Positron Emission Tomography Positron emission tomography (PET) is a medical imaging technique involving radiopharmaceuticals — substances that emit short-lived radiation. Although the first PET scanner was introduced in 1961, it took 15 more years before radiopharmaceuticals were combined with the technique and revolutionized its potential. One of the main requirements of a PET scan is a positron-emitting radioisotope, which is produced in a cyclotron and then attached to a substance used by the part of the body being... https://www.jove.com/v/13866 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14121.jpg Types of Reports II: Incident or Occurrence Report An Incident or Occurrence Report in a healthcare setting is a crucial document used to record any unexpected occurrence that may or may not have affected a patient, employee, or visitor. Such reports are critical to improving patient safety and include all details leading up to and including the event. Purposes: In the healthcare industry, reports play a crucial role in documenting incidents within an agency. The primary objective of these reports is to ensure patient safety, uphold the... https://www.jove.com/v/14121 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16374.jpg Radiological Investigation I: X-ray and CT Radiological investigations, including X-rays and computed tomography (CT) scans, are critical for diagnosing and evaluating various medical conditions. These imaging techniques provide valuable insights into the body's internal structures, aiding in the detection of abnormalities, assessment of disease progression, and development of treatment strategies. This article delves into two primary radiological investigations, chest X-rays and CT scans, outlining their purpose, procedures, and the... https://www.jove.com/v/16374 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16375.jpg Radiological Investigation II: MRI and Ventilation Perfusion Scan Description Magnetic Resonance Imaging (MRI) and Ventilation Perfusion Scans are two radiological investigations that offer detailed diagnostic images of the body, particularly lung structures. MRI MRI uses magnetic fields and radiofrequency signals to distinguish between normal and abnormal tissues. This technology provides a more detailed diagnostic image than CT scans, enabling it to characterize pulmonary nodules, stage bronchogenic carcinoma, and evaluate inflammatory activity in... https://www.jove.com/v/16375 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16376.jpg Radiological Investigation III: Pulmonary Angiogram and PET Scan Radiological investigations are paramount in the diagnosis and management of various pulmonary diseases. Two essential investigations are the Pulmonary Angiogram and the Positron Emission Tomography (PET) Scan. Pulmonary Angiogram A Pulmonary Angiogram is an invasive procedure involving injecting a contrast medium through a catheter threaded into the pulmonary artery or the right side of the heart to visualize the pulmonary vasculature. Computed Tomography (CT) scans have mainly replaced this... https://www.jove.com/v/16376 73 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17883.jpg Imaging Studies for Cardiovascular System III: X-Ray The most common cardiovascular diagnostic test is an X-ray. It produces images of the heart, blood vessels, and adjacent structures. Definition and Purpose An X-ray, or radiograph, is a non-invasive method that uses ionizing radiation to take images of internal structures. It is mainly used in cardiac imaging to examine the heart, lungs, and major blood vessels, aiming to identify abnormalities in the heart's size, shape, and position, such as heart failure, congenital defects, and vascular... https://www.jove.com/v/17883 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56245.jpg Expedited Radiation Biodosimetry by Automated Dicentric Chromosome Identification ADCI and Dose Estimation The cytogenetic dicentric chromosome (DC) assay quantifies exposure to ionizing radiation. The Automated Dicentric Chromosome Identifier and Dose Estimator software accurately and rapidly estimates biological dose from DCs in metaphase cells. It distinguishes monocentric chromosomes and other objects from DCs, and estimates biological radiation dose from the frequency of... https://www.jove.com/v/56245 633 16800 2017-09-04T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58392.jpg A Metadata Extraction Approach for Clinical Case Reports to Enable Advanced Understanding of Biomedical Concepts We present a protocol and associated metadata template for the extraction of text describing biomedical concepts in clinical case reports. The structured text values produced through this protocol can support deep analysis of thousands of clinical... https://www.jove.com/v/58392 470 16600 2018-09-20T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67904.jpg Longitudinal Micro-Computed Tomography Image Analysis for User-Defined Region of Interest in Critical-Sized Bone Defects We present a method for analyzing a user-defined region of interest (ROI) in a longitudinal in vivo rat radial defect model. This method enables comparative analysis between different scaffolds previously limited by variations in microcomputed tomography (µCT) scan field of view, specimen orientation, and baseline presence of... https://www.jove.com/v/67904 519 708 2025-06-24T13:20:00+00:00 JoVE no https://visualize.jove.com/26728880-a-computer-assisted-method-for-pathogenicity-assessment-and-genetic-reporting-of-variants-stored-in-the-australian-inherited-retinal-disease-register monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12025.jpg Genetic Screens Genetic screens are tools used to identify genes and mutations responsible for phenotypes of interest. Genetic screens help identify individuals or a group of people at risk of developing genetic diseases and help them with early intervention, targeted therapy, and reproductive options. Forward genetic screens Forward or “classical” genetic screens involve creating random mutations in an organism’s DNA using radiation, mutagens, or insertion of additional bases, which result in visible changes... https://www.jove.com/v/12025 166 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64284.jpg A Modified Murine Heterotopic Heart Transplant Protocol Matching Contemporary Standards of Aseptic Technique, Anesthesia, and Analgesia The present paper describes a modified technique for heterotopic vascularized cardiac transplantation with updated aseptic technique, analgesia, and... https://www.jove.com/v/64284 760 2200 2022-09-28T13:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66708.jpg An Automated Radiosynthesis of [ 68 Ga]Ga-FAPI-46 for Routine Clinical Use This work describes the automated production of up to 1.7 GBq of [68Ga]Ga-FAPI-46 on the iPHASE MultiSyn synthesizer for PET imaging of fibroblast activation... https://www.jove.com/v/66708 633 1800 2024-05-24T14:20:00+00:00 JoVE no https://visualize.jove.com/26834601-top-down-control-of-visual-alpha-oscillations-sources-of-control-signals-and-their-mechanisms-of-action monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10858.jpg Vision Vision is the result of light being detected and transduced into neural signals by the retina of the eye. This information is then further analyzed and interpreted by the brain. First, light enters the front of the eye and is focused by the cornea and lens onto the retina—a thin sheet of neural tissue lining the back of the eye. Because of refraction through the convex lens of the eye, images are projected onto the retina upside-down and reversed. Light is absorbed by the rod and cone... https://www.jove.com/v/10858 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14910.jpg Diencephalon: Thalamus and Information Relay The thalamus, often called “the gateway to the cerebral cortex,” is vital in processing and directing sensory and motor signals throughout the brain. Almost all inputs destined for the cerebral cortex, except for olfactory signals, are relayed through the thalamus. The thalamus is a sophisticated relay station, channeling information from various brain regions to the cerebral cortex, as well as a filter, prioritizing certain signals over others based on current physiological states or needs.<br... https://www.jove.com/v/14910 87 2025-06-13T16:11:46+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14936.jpg Hierarchy of Motor Control The hierarchy of motor control refers to the different levels of organization and processing involved in controlling movement in the body. These levels range from higher cortical areas involved in planning and decision-making to lower spinal cord reflexes that respond automatically to external stimuli. Segmental Level: This is the lowest level of motor control and consists of spinal cord segments. It is responsible for generating simple reflexes and rhythmic movements such as walking. Neural... https://www.jove.com/v/14936 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14938.jpg Indirect Motor Pathways The indirect motor or extrapyramidal pathways originate in the brainstem, the lower portion of the brain that connects it to the spinal cord. They consist of several distinct tracts, each with specialized functions. The four main tracts of the indirect motor pathways are the vestibulospinal tract, the reticulospinal tract, the tectospinal tract, and the rubrospinal tract. The vestibulospinal tract originates in the vestibular nuclei of the brainstem. The vestibular system detects changes in... https://www.jove.com/v/14938 82 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55089.jpg Automatic Detection of Highly Organized Theta Oscillations in the Murine EEG Theta activity in the hippocampus is related to specific cognitive and behavioral stages. Here, we describe an analytical method to detect highly-organized theta oscillations within the hippocampus using a time-frequency (i.e., wavelet analysis)-based... https://www.jove.com/v/55089 575 9800 2017-03-10T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57349.jpg Optogenetic Entrainment of Hippocampal Theta Oscillations in Behaving Mice We describe the use of optogenetics and electrophysiological recordings for selective manipulations of hippocampal theta oscillations (5-10 Hz) in behaving mice. The efficacy of the rhythm entrainment is monitored using local field potential. A combination of opto- and pharmacogenetic inhibition addresses the efferent readout of hippocampal... https://www.jove.com/v/57349 453 12400 2018-06-29T13:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58839.jpg Disruption of Frontal Lobe Neural Synchrony During Cognitive Control by Alcohol Intoxication This experiment uses an anatomically-constrained magnetoencephalography (aMEG) method to examine brain oscillatory dynamics and long-range functional synchrony during engagement of cognitive control as a function of acute alcohol... https://www.jove.com/v/58839 566 22300 2019-02-06T15:00:00+00:00 JoVE no https://visualize.jove.com/26881865-an-attentional-bias-for-lego-people-using-a-change-detection-task-are-lego-people-animate monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11044.jpg Schemas A schema is a mental construct consisting of a cluster or collection of related concepts (Bartlett, 1932). There are many different types of schemata, and they all have one thing in common: schemata are a method of organizing information that allows the brain to work more efficiently. When a schema is activated, the brain makes immediate assumptions about the person or object being observed. When people learn new information, they adjust their schemata through two processes: assimilation and... https://www.jove.com/v/11044 102 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11048.jpg The Anchoring-and-Adjustment Heuristic In order to make good decisions, we use our knowledge and our reasoning. Often, this knowledge and reasoning is sound and solid. However, sometimes, we are swayed by biases or by others manipulating a situation. For example, let’s say you and three friends wanted to rent a house and had a combined target budget of $1,600. The realtor shows you only very run-down houses for $1,600 and then shows you a very nice house for $2,000. Might you ask each person to pay more in rent to get the $2,000... https://www.jove.com/v/11048 85 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54856.jpg Measuring Attention and Visual Processing Speed by Model-based Analysis of Temporal-order Judgments Temporal-order judgments can be used to estimate processing speed parameters and attentional weights and thereby to infer the mechanisms of attentional processing. This methodology can be applied to a wide range of visual stimuli and works with many attention... https://www.jove.com/v/54856 780 10400 2017-01-23T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58053.jpg Using Rapid Serial Visual Presentation to Measure Set-Specific Capture, a Consequence of Distraction While Multitasking This method uses a dynamic visual display to index costs of distraction during visual search, including both "contingent attentional capture" and "set-specific capture," which is a cost of distraction that occurs when the participants maintain multiple search goals simultaneously. This method has revealed basic mechanisms and limitations of visual... https://www.jove.com/v/58053 358 9400 2018-08-29T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66919.jpg Block Building Task Identifies Distinct Groups of Left/Right-hand Choice Patterns After Unilateral Peripheral Nerve Injury The block-building task provides a rapid, objective, quantitative measurement of how often individuals choose to use their left versus right hand for reach-to-grasp action. After unilateral peripheral nerve injury, patients often shift to near-total usage of one hand, the direction of which is not predictable from other clinical... https://www.jove.com/v/66919 426 1200 2025-03-21T12:20:00+00:00 JoVE no https://visualize.jove.com/26971942-fuzzy-computer-aided-alzheimers-disease-diagnosis-based-on-mri-data monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40940/40940_article_thumb_40940.jpg Alzheimer Disease l: Introduction Alzheimer disease is a chronic, progressive, and irreversible neurodegenerative disorder and the most common cause of dementia in older adults. It leads to gradual neuronal loss, causing cognitive decline, behavioral changes, and loss of functional independence.Risk Factors and EtiologyThe disease is multifactorial. Age is the strongest risk factor, with prevalence doubling every 5 years after age 65. Genetic factors include mutations in genes such as APP, PSEN1, and PSEN2, which are associated... https://www.jove.com/v/40940 89 2026-04-15T17:31:37+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50887.jpg Lesion Explorer: A Video-guided, Standardized Protocol for Accurate and Reliable MRI-derived Volumetrics in Alzheimer's Disease and Normal Elderly Lesion Explorer (LE) is a semi-automatic, image-processing pipeline developed to obtain regional brain tissue and subcortical hyperintensity lesion volumetrics from structural MRI of Alzheimer's disease and normal elderly. To ensure a high level of accuracy and reliability, the following is a video-guided, standardized protocol for LE's manual... https://www.jove.com/v/50887 770 41000 2014-04-14T16:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56015.jpg Application of Granger Causality Analysis of the Directed Functional Connection in Alzheimer's Disease and Mild Cognitive Impairment Based on resting-state functional magnetic resonance imaging with Granger causality analysis, we investigated the alterations in the directed functional connectivity between the posterior cingulate cortex and whole brain in patients with Alzheimer's Disease (AD), patients with Mild Cognitive Impairment (MCI), and healthy... https://www.jove.com/v/56015 523 8500 2017-08-07T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67574.jpg Hybrid PET/MRI Imaging of Alzheimer's Disease Based on 18 F-AV-1451 This protocol describes the use of 18F-AV-1451 PET/MRI to reveal tau pathology and neurodegeneration, aiding neurologists in diagnosing Alzheimer's disease, assessing its severity, and gaining insights into its progression and underlying pathological... https://www.jove.com/v/67574 317 1100 2025-04-18T13:00:00+00:00 JoVE no https://visualize.jove.com/27013986-a-role-of-phase-resetting-in-coordinating-large-scale-neural-networks-during-attention-and-goal-directed-behavior monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14893.jpg Action Potential: Phases of Stimulation The action potential is a complex electrical event that occurs in excitable cells, such as neurons and muscle cells. It consists of several distinct phases, each with specific characteristics. Resting Phase: In this phase, the cell's membrane is at its resting potential, typically around -70 millivolts (mV) for neurons. Inside the cell, there is a higher concentration of potassium ions (K+) and a lower concentration of sodium ions (Na+). Voltage-gated sodium channels are closed, and... https://www.jove.com/v/14893 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16133.jpg Time and frequency -Domain Interpretation of Phase-lead Control Phase-lead controllers are commonly used in various control systems to enhance response speed and stability. Adjusting the brightness on a television screen offers a practical example of phase-lead control. When contrast is enhanced, a phase-lead controller is employed. Mathematically, phase-lead control is identified when the first parameter is smaller than the second. The design of phase-lead control involves the strategic placement of poles and zeros to balance steady-state error and system... https://www.jove.com/v/16133 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17785.jpg High-Level and Low-Level Awareness Controlled processes in human consciousness represent high-alert mental states where individuals deliberately focus their attention on achieving specific goals. Controlled processes can be seen in situations like mastering new technology, where a person might become so absorbed that they ignore surrounding distractions. Such processes involve selective attention, requiring one to concentrate on particular elements of experience while disregarding others. These are governed by executive... https://www.jove.com/v/17785 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17816.jpg Role of Shaping in Operant Conditioning Shaping is a technique used in operant conditioning to train complex behaviors by rewarding successive approximations toward the target behavior. This method is necessary because organisms are unlikely to perform complex behaviors spontaneously. Instead, shaping breaks down the desired behavior into small, manageable steps. The steps involved in shaping begin with reinforcing any response that resembles the desired behavior. For example, parents might praise a child for picking up one toy. As... https://www.jove.com/v/17816 79 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51944.jpg The Attentional Set Shifting Task: A Measure of Cognitive Flexibility in Mice The goal of this protocol is to perform a behavioral assay such as the attentional set shifting task (AST) to assess prefrontal cortex-mediated cognitive flexibility in... https://www.jove.com/v/51944 555 28700 2015-02-04T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53503.jpg An Operant Intra-/Extra-dimensional Set-shift Task for Mice Attentional set-shifting cognitive abnormalities are a core feature of many psychiatric diseases. Here, we present the development of a novel automatic system for the effective study of attentional set-shifting abilities, executive functions and other cognitive abilities in mice with high translational validity to human... https://www.jove.com/v/53503 515 12900 2016-01-22T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59117.jpg Simultaneous Eye Tracking and Single-Neuron Recordings in Human Epilepsy Patients We describe a method to conduct single-neuron recordings with simultaneous eye tracking in humans. We demonstrate the utility of this method and illustrate how we used this approach to obtain neurons in the human medial temporal lobe that encode targets of a visual... https://www.jove.com/v/59117 463 8400 2019-06-17T13:00:00+00:00 JoVE no https://visualize.jove.com/27510833-automatic-digital-plate-reading-for-surveillance-cultures monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/15851/15851_article_thumb_15851.png Determination of Crystal Structures In the late 1800s, the revelation that light extended beyond visible wavelengths led to the discovery of X-rays by Wilhelm Roentgen. Recognized as high-energy electromagnetic radiation with short wavelengths, X-rays prompted exploration into their interaction with crystals. Max von Laue proposed in 1912 that the periodic arrangement of atoms, ions, or molecules in crystals would cause them to diffract X-rays, a hypothesis confirmed through experiments with copper sulfate and zinc sulfide... https://www.jove.com/v/15851 89 2026-02-26T21:04:38+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19923/19923_article_thumb_19923.jpg Automatic Processing and Automatic Social Behavior Automatic processing refers to the cognitive operations that occur without conscious intent or awareness, playing a fundamental role in shaping social cognition and behavior. These processes enable individuals to navigate complex social environments efficiently by relying on mental shortcuts and pre-existing knowledge structures known as schemas. One of the most influential mechanisms underlying automatic processing is priming, which subtly activates mental representations through exposure to... https://www.jove.com/v/19923 88 2025-09-18T17:24:15+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40786/40786_article_thumb_40786.jpg Microbial Biosensors Microbial biosensors are analytical devices that utilize living microbes to detect specific substances through measurable signals. These devices consist of two main components: biosensing organisms and signal-transducing elements. Biosensing organisms, such as Escherichia coli or Saccharomyces cerevisiae, are typically housed in multiwell plates connected to transducers, enabling rapid, real-time detection of target analytes.Signal Generation MechanismWhen a target analyte—such as... https://www.jove.com/v/40786 77 2026-03-12T20:35:55+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40816/40816_article_thumb_40816.jpg Automated Microbial Diagnostics Automated diagnostic analyzers have transformed clinical microbiology by providing rapid and reliable methods for pathogen identification and antibiotic susceptibility testing. Among these systems, the Vitek 2 is widely used because it automates the traditionally labor-intensive processes of microbial identification (ID) and antibiotic susceptibility testing (AST), delivering standardized and timely results that are essential for effective patient care.Microbial Identification with ID CardsThe... https://www.jove.com/v/40816 84 2026-03-12T20:35:56+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58963.jpg Measuring the Shape and Size of Activated Sludge Particles Immobilized in Agar with an Open Source Software Pipeline The size and shape of particles in activated sludge are important parameters that are measured using varying methods. Inaccuracies arise from non-representative sampling, suboptimal images, and subjective analysis parameters. To minimize these errors and ease measurement, we present a protocol specifying every step, including an open source software... https://www.jove.com/v/58963 567 7500 2019-01-30T14:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65462.jpg Author Spotlight: Automated Lifespan Monitoring – Discovering Aging Dynamics with the Lifespan Machine The imaging platform "The Lifespan Machine" automates the lifelong observation of large populations. We show the steps required to perform lifespan, stress resistance, pathogenesis, and behavioral aging assays. The quality and scope of the data allow researchers to study interventions in aging despite the presence of biological and environmental... https://www.jove.com/v/65462 533 1700 2024-01-26T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68448.jpg Efficient Sampling of Genetically Encoded Biosensor Design Space Enabled with a Design of Experiments and Automation Workflow This protocol provides a method for the systematic global optimization of genetically encoded biosensors through automation-assisted genetic library generation and assessment. This is coupled with design-of-experiment methodologies to streamline experimentation and enable the selection of genetic components to tune biosensors to specific design outcomes. https://www.jove.com/v/68448 538 783 2025-10-17T12:50:00+00:00 JoVE no https://visualize.jove.com/27634979-recommendations-for-nuclear-medicine-technologists-drawn-from-an-analysis-of-errors-reported-in-australian-radiation-incident-registers monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13313.jpg Errors occurring during blood pressure monitoring Blood pressure monitoring is a crucial clinical procedure in diagnosing and managing various cardiovascular conditions. Despite its significance, the accuracy of blood pressure measurements can be compromised by multiple factors, potentially leading to either falsely high or low readings. These inaccuracies are critical as they can significantly impact patient care. So, it is vital to understand these challenges deeply and adopt strategic approaches to minimize errors. Several factors... https://www.jove.com/v/13313 85 1700 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13866.jpg Positron Emission Tomography Positron emission tomography (PET) is a medical imaging technique involving radiopharmaceuticals — substances that emit short-lived radiation. Although the first PET scanner was introduced in 1961, it took 15 more years before radiopharmaceuticals were combined with the technique and revolutionized its potential. One of the main requirements of a PET scan is a positron-emitting radioisotope, which is produced in a cyclotron and then attached to a substance used by the part of the body... https://www.jove.com/v/13866 89 7900 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14121.jpg Types of Reports II: Incident or Occurrence Report An Incident or Occurrence Report in a healthcare setting is a crucial document used to record any unexpected occurrence that may or may not have affected a patient, employee, or visitor. Such reports are critical to improving patient safety and include all details leading up to and including the event. Purposes: In the healthcare industry, reports play a crucial role in documenting incidents within an agency. The primary objective of these reports is to ensure patient safety, uphold the... https://www.jove.com/v/14121 81 1300 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16374.jpg Radiological Investigation I: X-ray and CT Radiological investigations, including X-rays and computed tomography (CT) scans, are critical for diagnosing and evaluating various medical conditions. These imaging techniques provide valuable insights into the body's internal structures, aiding in the detection of abnormalities, assessment of disease progression, and development of treatment strategies. This article delves into two primary radiological investigations, chest X-rays and CT scans, outlining their purpose, procedures, and... https://www.jove.com/v/16374 90 1500 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16375.jpg Radiological Investigation II: MRI and Ventilation Perfusion Scan Description Magnetic Resonance Imaging (MRI) and Ventilation Perfusion Scans are two radiological investigations that offer detailed diagnostic images of the body, particularly lung structures. MRI MRI uses magnetic fields and radiofrequency signals to distinguish between normal and abnormal tissues. This technology provides a more detailed diagnostic image than CT scans, enabling it to characterize pulmonary nodules, stage bronchogenic carcinoma, and evaluate inflammatory activity in... https://www.jove.com/v/16375 90 806 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16376.jpg Radiological Investigation III: Pulmonary Angiogram and PET Scan Radiological investigations are paramount in the diagnosis and management of various pulmonary diseases. Two essential investigations are the Pulmonary Angiogram and the Positron Emission Tomography (PET) Scan. Pulmonary Angiogram A Pulmonary Angiogram is an invasive procedure involving injecting a contrast medium through a catheter threaded into the pulmonary artery or the right side of the heart to visualize the pulmonary vasculature. Computed Tomography (CT) scans have mainly replaced this... https://www.jove.com/v/16376 73 600 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50299.jpg Magnetically-Assisted Remote Controlled Microcatheter Tip Deflection under Magnetic Resonance Imaging Current applied to an endovascular microcatheter with microcoil tip made by laser lathe lithography can achieve controllable deflections under magnetic resonance (MR) guidance, which may improve speed and efficacy of navigation of vasculature during various endovascular procedures. https://www.jove.com/v/50299 687 2013-04-04T19:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54807.jpg Laser-heating and Radiance Spectrometry for the Study of Nuclear Materials in Conditions Simulating a Nuclear Power Plant Accident We present experiments in which real nuclear fuel, cladding, and containment materials are laser heated to temperatures beyond 3,000 K while their behavior is studied by radiance spectroscopy and thermal analysis. These experiments simulate, on a laboratory scale, the formation of a lava-phase following a nuclear reactor core meltdown. https://www.jove.com/v/54807 558 2017-12-14T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61688.jpg Neutron Radiography and Computed Tomography of Biological Systems at the Oak Ridge National Laboratory's High Flux Isotope Reactor This manuscript describes a protocol for neutron radiography and computed tomography of biological samples using a High Flux Isotope Reactor (HFIR) CG-1D beamline to measure a metal implant in a rat femur, a mouse lung, and an herbaceous plant root/soil system. https://www.jove.com/v/61688 624 2021-05-07T19:30:00+00:00 JoVE no https://visualize.jove.com/27720945-evaluation-of-the-rapid-influenza-detection-tests-gold-sign-flu-and-quick-navi-flu-for-the-detection-of-influenza-a-and-b-virus-antigens-in-adults-during-the-influenza-season monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2829.jpg Rapid Diagnosis of Avian Influenza Virus in Wild Birds: Use of a Portable rRT-PCR and Freeze-dried Reagents in the Field This study describes diagnosis of avian influenza in wild birds using a portable rRT-PCR system. The method takes advantage of freeze-dried reagents to screen wild birds in a non-laboratory setting, typical of an outbreak scenario. Use of molecular tools provides accurate and sensitive alternatives for rapid... https://www.jove.com/v/2829 526 16200 2011-08-02T12:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/3623.jpg High-throughput Detection Method for Influenza Virus This method describes the use of Infrared dye based imaging system for detection of H1N1 in bronchioalveolar lavage (BAL) fluid of infected mice at a high sensitivity. This methodology can be performed in a 96- or 384-well plate, requires <10 μl volume of test material and has the potential for concurrent screening of multiple... https://www.jove.com/v/3623 605 26900 2012-02-04T14:00:00+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40845/40845_article_thumb_40845.jpg Influenza Influenza is an acute, highly communicable viral disease that affects the respiratory tract and is responsible for seasonal epidemics worldwide. Influenza A is the most prevalent type associated with widespread outbreaks and is subtyped based on two surface glycoproteins: hemagglutinin (H) and neuraminidase (N), as in H1N1. These glycoproteins are essential for viral infectivity, transmission, and immune recognition. Transmission occurs primarily through respiratory droplets and contaminated... https://www.jove.com/v/40845 87 2026-03-12T20:35:52+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54312.jpg Rapid Molecular Detection and Differentiation of Influenza Viruses A and B We describe a rapid, molecular-based Influenza A and B assay. The Influenza assay detects each target within 15 min by employing isothermal amplification with influenza-specific primers followed by target detection with molecular beacon probes. The Influenza A and B assay is user-friendly and required minimal hands-on time to... https://www.jove.com/v/54312 338 16200 2017-01-30T14:00:00+00:00 JoVE no https://visualize.jove.com/28098822-application-of-fault-tree-analysis-and-fuzzy-neural-networks-to-fault-diagnosis-in-the-internet-of-things-iot-for-aquaculture monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12979.jpg Issues And Trends In Healthcare Delivery System The issues and trends in healthcare delivery are constantly changing. The COVID-19 pandemic is one recent issue that wreaked havoc on healthcare systems, causing a shortage of healthcare workers, high demand for medicines and supplies, and increased medical expenditure due to a lack of insurance. Other issues include rising healthcare costs and care fragmentation. Cost Containment Payment for healthcare services has historically promoted adoption of costly and often unnecessary or inefficient... https://www.jove.com/v/12979 89 6300 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16155.jpg Bus Impedance Matrix Calculating subtransient fault currents for three-phase faults in an N-bus power system involves using the positive-sequence network. When a three-phase short circuit occurs at a specific bus, the analysis uses the superposition method to evaluate two separate circuits. In the first circuit, all machine voltage sources are short-circuited, leaving only the prefault voltage source at the fault location. The positive-sequence bus impedance matrix can be determined by solving the nodal equations,... https://www.jove.com/v/16155 84 551 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16159.jpg Fault Types When analyzing a single line-to-ground fault from phase A to ground at a three-phase bus, it is important to consider the fault impedance. This impedance is zero for a bolted fault, equal to the arc impedance for an arcing fault, and represents the total fault impedance for a transmission-line insulator flashover. To derive sequence and phase currents, fault conditions are translated from the phase domain to the sequence domain. For line-to-line faults occurring between phases B and C, the... https://www.jove.com/v/16159 78 464 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68888.jpg Simulation of a Scaled Assembly Process with Collaboration of a Robotic Arm and Monitoring through a Vision System for Quality Control Here, we present a protocol for the simulation and monitoring of a scaled semi-automated assembly process, through the collaboration of a collaborative robot and verification via a computer vision system for quality control. https://www.jove.com/v/68888 347 2025-08-29T21:45:00+00:00 JoVE no https://visualize.jove.com/28182453-action-at-its-place-contextual-settings-enhance-action-recognition-in-4-to-8-year-old-children monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10919.jpg Fixed Action Patterns A fixed action pattern (FAP) is a specific, hard-wired sequence of behaviors that occurs in response to an external stimulus, called a sign stimulus. The behavior is “fixed” because it is essentially unchangeable—proceeding similarly across individuals of a species every time it occurs. Three-Spined Sticklebacks A classic example of a FAP was described in three-spined stickleback fish by Nikolaas Tinbergen in the 1930s. During the breeding season, the male fish develop a red throat and belly... https://www.jove.com/v/10919 66 JoVE no https://cloudfront.jove.com/files/ftp_upload/19923/19923_article_thumb_19923.jpg Automatic Processing and Automatic Social Behavior Automatic processing refers to the cognitive operations that occur without conscious intent or awareness, playing a fundamental role in shaping social cognition and behavior. These processes enable individuals to navigate complex social environments efficiently by relying on mental shortcuts and pre-existing knowledge structures known as schemas. One of the most influential mechanisms underlying automatic processing is priming, which subtly activates mental representations through exposure to... https://www.jove.com/v/19923 88 2025-09-18T10:24:15+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52841.jpg Quantifying Learning in Young Infants: Tracking Leg Actions During a Discovery-learning Task A method is described in which 3-4 month old infants learn a task by discovery and their leg movements are captured to quantify the learning... https://www.jove.com/v/52841 678 11200 2015-06-01T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58496.jpg Gaze in Action: Head-mounted Eye Tracking of Children's Dynamic Visual Attention During Naturalistic Behavior Young children do not passively observe the world, but rather actively explore and engage with their environment. This protocol provides guiding principles and practical recommendations for using head-mounted eye trackers to record infants' and toddlers' dynamic visual environments and visual attention in the context of natural... https://www.jove.com/v/58496 429 11600 2018-11-14T13:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65436.jpg Author Spotlight: A Novel Setup to Conduct Naturalistic Laboratory Experiments with Real Human Actors in Scenarios This study presents a naturalistic experimental setup that allows researchers to present real-time action stimuli, obtain response time and mouse tracking data while participants respond after each stimulus display, and change actors between experimental conditions with a unique system including a special transparent organic light-emitting diode (OLED) screen and light... https://www.jove.com/v/65436 463 2800 2023-08-04T12:40:00+00:00 JoVE no https://visualize.jove.com/28210601-health-technology-assessment-a-necessity-in-post-sanctions-iran-while-implementing-the-health-transformation-plan monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12964.jpg Introduction To Health Care Delivery System The healthcare system is constantly changing and complex. Various services are available from different healthcare providers, but gaining access to these services has become challenging for people with limited healthcare insurance. Uninsured people present a challenge to healthcare because they frequently postpone or forego treatment. The Institute of Medicine (IOM) advocates for a patient-centered, effective, safe, timely, equitable, and effective healthcare system. The National Priorities... https://www.jove.com/v/12964 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12965.jpg Methods Of Healthcare Delivery System At the different levels of the healthcare system, we see varying methods of healthcare used. These methods include managed care systems, case management, and primary healthcare. Managed Care System: The managed care system is designed to control the cost while maintaining the quality of care. The patient's care from admission to discharge is planned by the primary care provider or the case manager, also known as the gatekeeper. In a managed care system, the number of care providers is limited... https://www.jove.com/v/12965 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12967.jpg Primary Healthcare Services Primary care promotes wellness and prevents disease. This care includes health promotion, education, protection (such as immunizations), early disease screening, and environmental considerations. Settings providing this type of healthcare include physician offices, public health clinics, school nursing, and community health nursing. In 1978, international leaders convened in Alma-Ata, Kazakhstan, for what would be a pivotal event in global health. The Alma-Ata Declaration was the first to call... https://www.jove.com/v/12967 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12979.jpg Issues And Trends In Healthcare Delivery System The issues and trends in healthcare delivery are constantly changing. The COVID-19 pandemic is one recent issue that wreaked havoc on healthcare systems, causing a shortage of healthcare workers, high demand for medicines and supplies, and increased medical expenditure due to a lack of insurance. Other issues include rising healthcare costs and care fragmentation. Cost Containment Payment for healthcare services has historically promoted adoption of costly and often unnecessary or inefficient... https://www.jove.com/v/12979 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13237.jpg Healthcare Associated Infections II: Preventive Measures Essential infection prevention measures are based on the knowledge of the infection chain, the modes of transmission in healthcare settings, and the use of the best practices in all healthcare settings. Compulsory public reporting of healthcare-associated infection rates is needed to allow individuals and the community to make informed choices regarding selecting a healthcare facility. The best practices for preventing healthcare-associated infections include hand hygiene, patient risk... https://www.jove.com/v/13237 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14125.jpg Health Information Technology and Healthcare Information System Health Information Technology (HIT) Health Information Technology, commonly called HIT, integrates advanced information systems and technology in healthcare settings. Its primary functions include: Documentation and Monitoring of Patient Care: HIT systems facilitate the efficient recording and tracking of patient data, aiding healthcare providers in monitoring patients' health status and making informed decisions. Managerial and Organizational Functions: Beyond patient care, HIT is... https://www.jove.com/v/14125 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59019.jpg A Novel Digital Platform for a Monitored Home-based Cardiac Rehabilitation Program The aim is to promote a new approach to cardiac rehabilitation (CR), using a unique remote patient monitoring system that will enable healthcare providers to monitor CR patients at home at low cost, with the intention of making CR services more accessible and improving compliance. The study is currently underway. https://www.jove.com/v/59019 264 12200 2019-04-19T12:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61899.jpg Digital Home-Monitoring of Patients after Kidney Transplantation: The MACCS Platform The MACCS platform is a comprehensive telemedicine concept aiming at better outcomes after kidney transplantation by sharing key medical information between patients and physicians. A telemedicine team reviews incoming data to detect potential complications and to improve adherence in kidney transplant recipients to achieve better long-term... https://www.jove.com/v/61899 433 4800 2021-04-12T11:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65810.jpg Author Spotlight: Developing a Point-of-Care Hemoglobin Estimation Method for Anemia Management An accurate hemoglobin estimation method is lacking at the point of care and may hinder population-based programs for treating anemia. Therefore, we developed a point-of-care method based on pooled capillary blood and an auto-analyzer integrated into a custom software application to categorize the hemoglobin values into different grades of anemia. https://www.jove.com/v/65810 335 1300 2024-01-19T13:20:00+00:00 JoVE no https://visualize.jove.com/28268268-the-brain-can-mix-different-control-strategies-in-a-task-oriented-and-multi-referential-manner-a-simulation-study monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2320.jpg Combining Computer Game-Based Behavioural Experiments With High-Density EEG and Infrared Gaze Tracking Procedures for recording high-density EEG and gaze data during computer game-based cognitive tasks are described. Using a video game to present cognitive tasks enhances ecological validity without sacrificing experimental... https://www.jove.com/v/2320 820 17300 2010-12-16T17:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16107.jpg Multi-input and Multi-variable systems Cruise control systems in cars are designed as multi-input systems to maintain a driver's desired speed while compensating for external disturbances such as changes in terrain. The block diagram for a cruise control system typically includes two main inputs: the desired speed set by the driver and any external disturbances, such as the incline of the road. By adjusting the engine throttle, the system maintains the vehicle's speed as close to the desired value as possible. In the absence of... https://www.jove.com/v/16107 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17779.jpg Parallel Processing The brain processes sensory information rapidly due to parallel processing, which involves sending data across multiple neural pathways at the same time. This method allows the brain to manage various sensory qualities, such as shapes, colors, movements, and locations, all concurrently. For instance, when observing a forest landscape, the brain simultaneously processes the movement of leaves, the shapes of trees, the depth between them, and the various shades of green. This enables a quick and... https://www.jove.com/v/17779 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17785.jpg High-Level and Low-Level Awareness Controlled processes in human consciousness represent high-alert mental states where individuals deliberately focus their attention on achieving specific goals. Controlled processes can be seen in situations like mastering new technology, where a person might become so absorbed that they ignore surrounding distractions. Such processes involve selective attention, requiring one to concentrate on particular elements of experience while disregarding others. These are governed by executive... https://www.jove.com/v/17785 79 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51128.jpg A Fully Automated Rodent Conditioning Protocol for Sensorimotor Integration and Cognitive Control Experiments A fully automated protocol for rodent operant conditioning is proposed. The protocol relies on precise temporal control of behavioral events to investigate the extent to which this control influences neural activity underlying sensorimotor integration and cognitive control... https://www.jove.com/v/51128 583 11100 2014-04-15T18:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67500.jpg Online Repetitive Transcranial Magnetic Stimulation of Dorsomedial and Dorsolateral Prefrontal Cortex in Cognition Decision Making, and Cognitive Dissonance This protocol presents a more precise and effective method of repetitive transcranial magnetic stimulation of the dorsolateral and dorsomedial prefrontal cortices during an experimental task using neuronavigation and robotic systems. Based on the results, crucial implications are suggested for future online stimulation... https://www.jove.com/v/67500 800 1100 2025-12-05T12:30:00+00:00 JoVE no https://visualize.jove.com/28274467-an-iphone-application-for-upper-arm-posture-and-movement-measurements monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13277.jpg Assessing Body Temperature - Axilla Procedural Guide for Assessing Axillary Body Temperature using a Digital Thermometer: Step 1: Perform hand hygiene and put on clean gloves to maintain infection control and prevent cross-contamination. Step 2: Prepare the patient by explaining the procedure to ensure understanding and cooperation. Ensure privacy, expose the axilla, and inform the patient that minimal movement is crucial for an accurate reading. Step 3: Adjust the patient’s clothing to expose only the axilla. It minimizes... https://www.jove.com/v/13277 74 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54659.jpg Video Movement Analysis Using Smartphones ViMAS: A Pilot Study This manuscript describes the method to test the concurrent validity of kinematic measures recorded by the smartphone application in comparison to a 3D motion capture system in the sagittal plane. This protocol will enable clinicians to set up smartphones for video capture of human... https://www.jove.com/v/54659 471 17300 2017-03-14T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57014.jpg An Objective and Child-friendly Assessment of Arm Function by Using a 3-D Sensor An objective measure of muscle functions is challenging especially in children. Based on a commercially available digital 3-D sensor, a child-friendly gaming test was developed to assess upper limb function for clinical... https://www.jove.com/v/57014 445 7300 2018-02-12T14:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63169.jpg An Application for Pairing with Wearable Devices to Monitor Personal Health Status The present protocol introduces a non-commercial self-developed application for collecting real-time on-site data, including psychological scales, GPS location, heart rate, and blood-oxygen saturation level, as well as the application's operating procedures. An empirical study conducted in Taiwan in 2020 was used as an application... https://www.jove.com/v/63169 418 3500 2022-02-03T13:00:00+00:00 JoVE no https://visualize.jove.com/28293571-virtual-reality-augmented-realityi-call-it-i-reality monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14355.jpg Virtual Work The principle of virtual work states that if a body is in static and dynamic equilibrium, then the sum of all the virtual work done by all external forces and couple moments for any given virtual displacement must be zero. In static equilibrium, a body can experience an imaginary or virtual movement, such as displacement or rotation. The virtual work done by a force is equal to the dot product of force and virtual displacement in the direction of the force. When it comes to virtually rotating a... https://www.jove.com/v/14355 80 1600 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55965.jpg Using Virtual Reality to Transfer Motor Skill Knowledge from One Hand to Another We describe a novel virtual-reality based setup which exploits voluntary control of one hand to improve motor-skill performance in the other (non-trained) hand. This is achieved by providing real-time movement-based sensory feedback as if the non-trained hand is moving. This new approach may be used to enhance rehabilitation of patients with unilateral... https://www.jove.com/v/55965 312 549100 2017-09-18T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67096.jpg Author Spotlight: Revolutionizing Remote Surgery with Augmented Reality and Robotics for Enhanced Precision and Accessibility This article presents the design and implementation of an automatic surgery module based on augmented reality (AR)- based 3D reconstruction. The system enables remote surgery by allowing surgeons to inspect reconstructed features and replicate surgical hand movements as if they were performing the surgery in close proximity. https://www.jove.com/v/67096 466 1200 2024-08-09T14:25:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68386.jpg Photorealistic Learned Landscapes for Augmented Reality This paper presents a system for photorealistic 3D reconstruction using 360-degree images, Gaussian Splatting, and virtual reality integration. The approach can be applied to different applications such as education, simulating learning environments; construction, to simulate works off-sites and retrieve metrics; or healthcare, to train autistic people in daily-life tasks. https://www.jove.com/v/68386 414 834 2025-06-27T13:20:00+00:00 JoVE no https://visualize.jove.com/28362599-adaptive-neural-control-of-uncertain-nonlinear-systems-using-disturbance-observer monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16031.jpg Control Systems Control systems are everywhere in contemporary society, influencing diverse applications from aerospace to automated manufacturing. These systems can be found naturally within biological processes, such as blood sugar regulation and heart rate adjustment in response to stress, as well as in man-made systems like elevators and automated vehicles. A control system is essentially a network of subsystems and processes that collaboratively convert specific inputs into desired outputs. At the heart... https://www.jove.com/v/16031 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16092.jpg Open and closed-loop control systems Control systems are foundational elements in automation and engineering. They are broadly categorized into open-loop and closed-loop systems. These classifications hinge on the presence or absence of feedback mechanisms, significantly influencing the system's performance, complexity, and application. An open-loop control system operates without feedback from the output. It consists of two primary elements: the controller and the controlled process. The controller receives an input signal and... https://www.jove.com/v/16092 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16094.jpg Feedback control systems Feedback control systems are categorized in various ways based on their design, analysis, and signal types. Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity... https://www.jove.com/v/16094 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16125.jpg Controller Configurations Controller configurations are crucial in a car's cruise control system because they manage speed over time to maintain a consistent pace regardless of road conditions, thereby meeting design goals. In traditional control systems, fixed-configuration design involves predetermined controller placement. System performance modifications are known as compensation. Control-system compensation involves various configurations, most commonly series or cascade compensation, in which the controller aligns... https://www.jove.com/v/16125 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16126.jpg PD Controller: Design In automotive engineering, car suspension systems often employ Proportional Derivative (PD) controllers to enhance performance. PD controllers are utilized to adjust the damping force in response to road conditions. A controller, acting as an amplifier with a constant gain, demonstrates proportional control, with output directly mirroring input. Designing a continuous-data controller requires selecting and linking components like adders and integrators, which are fundamental in Proportional,... https://www.jove.com/v/16126 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16127.jpg Time-Domain Interpretation of PD Control Proportional-Derivative (PD) control is a widely used control method in various engineering systems to enhance stability and performance. In a system with only proportional control, common issues include high maximum overshoot and oscillation, observed in both the error signal and its rate of change. This behavior can be divided into three distinct phases: initial overshoot, subsequent undershoot, and gradual stabilization. Consider the example of control of motor torque. Initially, a positive... https://www.jove.com/v/16127 67 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60078.jpg Experimental Methods to Study Human Postural Control This article presents an experimental/analytic framework to study human postural control. The protocol provides step-by-step procedures for performing standing experiments, measuring body kinematics and kinetics signals, and analyzing the results to provide insight into the mechanisms underlying human postural control. https://www.jove.com/v/60078 492 2019-09-11T07:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61092.jpg WheelCon: A Wheel Control-Based Gaming Platform for Studying Human Sensorimotor Control WheelCon is a novel, free and open-source platform to design video games that noninvasively simulates mountain biking down a steep, twisting, bumpy trail. It contains components presenting in human sensorimotor control (delay, quantization, noise, disturbance, and multiple feedback loops) and allows researchers to study the layered architecture in sensorimotor control. https://www.jove.com/v/61092 498 2020-08-15T05:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63342.jpg Interactive and Visualized Online Experimentation System for Engineering Education and Research This work describes an online experimentation system that provides visualized experiments, including the visualization of theories, concepts, and formulas, visualizing the experimental process with three-dimensional (3-D) virtual test rigs, and visualizing the control and monitoring system using widgets such as charts and cameras. https://www.jove.com/v/63342 515 2021-11-24T06:00:00+00:00 JoVE no https://visualize.jove.com/28378515-cross-sensory-modulation-of-alpha-oscillatory-activity-suppression-idling-and-default-resource-allocation monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18207.jpg Optimal Arousal Theory The optimal arousal theory suggests that performance is maximized when an individual experiences a moderate level of arousal. This theory is closely tied to the Yerkes-Dodson law, which illustrates an inverted U-shaped relationship between arousal and performance. The law, formulated by psychologists Robert Yerkes and John Dodson, implies an ideal arousal level for optimal performance, and deviations from this level can lead to declines in effectiveness. Inverted U-Shaped Performance Curve The... https://www.jove.com/v/18207 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58839.jpg Disruption of Frontal Lobe Neural Synchrony During Cognitive Control by Alcohol Intoxication This experiment uses an anatomically-constrained magnetoencephalography (aMEG) method to examine brain oscillatory dynamics and long-range functional synchrony during engagement of cognitive control as a function of acute alcohol intoxication. https://www.jove.com/v/58839 566 2019-02-06T23:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65212.jpg Combined Peripheral Nerve Stimulation and Controllable Pulse Parameter Transcranial Magnetic Stimulation to Probe Sensorimotor Control and Learning Short-latency afferent inhibition (SAI) is a transcranial magnetic stimulation protocol to probe sensorimotor integration. This article describes how SAI can be used to study the convergent sensorimotor loops in the motor cortex during sensorimotor behavior. https://www.jove.com/v/65212 887 2023-04-21T21:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67500.jpg Online Repetitive Transcranial Magnetic Stimulation of Dorsomedial and Dorsolateral Prefrontal Cortex in Cognition Decision Making, and Cognitive Dissonance This protocol presents a more precise and effective method of repetitive transcranial magnetic stimulation of the dorsolateral and dorsomedial prefrontal cortices during an experimental task using neuronavigation and robotic systems. Based on the results, crucial implications are suggested for future online stimulation research. https://www.jove.com/v/67500 800 2025-12-05T20:30:00+00:00 JoVE no https://visualize.jove.com/28381339-association-of-mortality-and-phase-angle-measured-by-different-bioelectrical-impedance-analysis-bia-devices monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15102.jpg Bode Plots Construction The Bode plot is an essential tool in control system analysis, mapping the frequency response of a system through a magnitude plot and a phase plot, both against a logarithmic frequency axis. To construct a Bode plot, consider the transfer function H(ω): It has constant gain, zeros, and poles. After normalizing the transfer function is written as: Each term in this normalized function affects the Bode plot distinctly. The term 10jω has a constant gain of 10 and zero at origin jω. Each simple... https://www.jove.com/v/15102 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64331.jpg Evaluation of Fluid Overload by Bioelectrical Impedance Vectorial Analysis In this study, we demonstrate how to evaluate the presence of fluid overload through bioelectrical impedance vectorial analysis (BIVA) and the impedance ratio measured using tetrapolar multi-frequency equipment in patients admitted to the emergency department. BIVA and impedance ratio are reliable and useful tools to predict poor outcomes. https://www.jove.com/v/64331 437 2022-08-17T21:40:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65660.jpg Clinical Application of Phase Angle and BIVA Z-Score Analyses in Patients Admitted to an Emergency Department with Acute Heart Failure In this protocol, we explain how to obtain and interpret phase angle values and bioelectrical impedance vectorial analysis (BIVA) Z-score obtained by bioelectrical impedance in patients with acute heart failure admitted to the Emergency Department and their clinical applicability as a predictive marker for the prognosis of a 90-day event. https://www.jove.com/v/65660 245 2023-06-30T20:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68203.jpg Cutoff Value of Phase Angle by Bioelectrical Impedance Analysis at Admission as a Prognostic Factor in Patients with Acute Heart Failure This protocol presents R codes for performing restricted cubic spline multivariable Cox regression analysis to determine the cutoff value of the phase angle for prognosis in acute heart failure as well as codes for calculating statistics that measure the discriminatory ability of each model and evaluate its goodness of fit. https://www.jove.com/v/68203 316 2025-06-10T20:40:00+00:00 JoVE no https://visualize.jove.com/28399463-distraction-or-cognitive-overload-using-modulations-of-the-autonomic-nervous-system-to-discriminate-the-possible-negative-effects-of-advanced-assistance-system monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2434.jpg Brain Imaging Investigation of the Impairing Effect of Emotion on Cognition We present a protocol that allows investigation of the neural mechanisms mediating the detrimental impact of emotion on cognition, using functional magnetic resonance imaging. This protocol can be used with both healthy and clinical participants. https://www.jove.com/v/2434 968 2012-02-01T12:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14947.jpg Autonomic Nervous System The autonomic nervous system (ANS) is a critical component of the peripheral nervous system, primarily responsible for regulating involuntary bodily functions and maintaining homeostasis. It functions in tandem with the central nervous system (CNS) to seamlessly coordinate various physiological processes without the need for conscious control. The ANS comprises two main divisions: the sympathetic and parasympathetic divisions. These divisions function antagonistically to maintain a dynamic... https://www.jove.com/v/14947 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14959.jpg Disorders of the Autonomic Nervous System The autonomic nervous system (ANS) is an intricate network of nerves that controls functions such as the regulation of heart rate, digestion, and blood pressure regulation. When this system malfunctions, it can lead to various disorders that affect multiple bodily functions. One common feature of many autonomic disorders is the involvement of smooth blood vessels, which play a crucial role in regulating blood flow throughout the body. Raynaud's disease, also known as Raynaud's phenomenon, is a... https://www.jove.com/v/14959 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17785.jpg High-Level and Low-Level Awareness Controlled processes in human consciousness represent high-alert mental states where individuals deliberately focus their attention on achieving specific goals. Controlled processes can be seen in situations like mastering new technology, where a person might become so absorbed that they ignore surrounding distractions. Such processes involve selective attention, requiring one to concentrate on particular elements of experience while disregarding others. These are governed by executive... https://www.jove.com/v/17785 79 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52226.jpg A Cognitive Paradigm to Investigate Interference in Working Memory by Distractions and Interruptions A novel cognitive paradigm is developed to elucidate behavioral and neural correlates of interference by to-be-ignored distractors versus interference by to-be-attended interruptors during a working memory task. In this manuscript, several variants of this paradigm are detailed, and data obtained with this paradigm in younger/older adult participants is reviewed. https://www.jove.com/v/52226 638 2015-07-16T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61943.jpg Real-Time Proxy-Control of Re-Parameterized Peripheral Signals using a Close-Loop Interface We present protocols and methods of analyses to build co-adaptive interfaces that stream, parameterize, analyze, and modify human body and heart signals in close-loop. This setup interfaces signals derived from the peripheral and central nervous systems of the person with external sensory inputs to help track biophysical change. https://www.jove.com/v/61943 714 2021-05-08T14:30:00+00:00 JoVE no https://visualize.jove.com/28405378-a-unified-model-of-the-standard-genetic-code monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10798.jpg The Central Dogma Overview The central dogma of biology states that information encoded in the DNA is transferred to messenger RNA (mRNA), which then directs the synthesis of protein. The set of instructions that enable the mRNA nucleotide sequence to be decoded into amino acids is called the genetic code. The universal nature of this genetic code has spurred advances in scientific research, agriculture, and medicine. RNA Is the Missing Link between DNA and Proteins In the early 1900s, scientists discovered... https://www.jove.com/v/10798 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11476.jpg From DNA to Protein The flow of genetic information in cells from DNA to mRNA to protein is described by the central dogma, which states that genes specify the sequence of mRNAs, which in turn specify the sequence of amino acids making up all proteins. The decoding of one molecule to another is performed by specific proteins and RNAs. Because the information stored in DNA is so central to cellular function, it makes intuitive sense that the cell would make mRNA copies of this information for protein synthesis... https://www.jove.com/v/11476 186 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10798.jpg The Central Dogma Overview The central dogma of biology states that information encoded in the DNA is transferred to messenger RNA (mRNA), which then directs the synthesis of protein. The set of instructions that enable the mRNA nucleotide sequence to be decoded into amino acids is called the genetic code. The universal nature of this genetic code has spurred advances in scientific research, agriculture, and medicine. RNA Is the Missing Link between DNA and Proteins In the early 1900s, scientists discovered... https://www.jove.com/v/11479 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11527.jpg DNA as a Genetic Template Two structural features of the DNA molecule provide a basis for the mechanisms of heredity: the four nucleotide bases and its double-stranded nature. The Watson-Crick model of double-helical DNA structure, proposed in 1952, drew heavily upon the X-ray crystallography work of researchers Rosalind Franklin and Maurice Wilkins. Watson, Crick, and Wilkins jointly received the Nobel Prize in Physiology or Medicine for their work in 1962. Franklin was, controversially, excluded from the prize for... https://www.jove.com/v/11527 125 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12442.jpg The Central Dogma The central dogma explains the flow of genetic information from DNA nucleotides to the amino acid sequence of proteins. RNA is the Missing Link Between DNA and Proteins In the early 1900s, scientists discovered that DNA stores all the information needed for cellular functions and that proteins perform most of these functions. However, the mechanisms of converting genetic information into functional proteins remained unknown for many years. Initially, it was believed that a single gene is... https://www.jove.com/v/12442 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12442.jpg The Central Dogma The central dogma explains the flow of genetic information from DNA nucleotides to the amino acid sequence of proteins. RNA is the Missing Link Between DNA and Proteins In the early 1900s, scientists discovered that DNA stores all the information needed for cellular functions and that proteins perform most of these functions. However, the mechanisms of converting genetic information into functional proteins remained unknown for many years. Initially, it was believed that a single gene is... https://www.jove.com/v/13944 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54273.jpg Residue-specific Incorporation of Noncanonical Amino Acids into Model Proteins Using an Escherichia coli Cell-free Transcription-translation System An easy-to-use, cell-free expression protocol for the residue-specific incorporation of noncanonical amino acid analogs into proteins, including downstream analysis, is presented for medical, pharmaceutic, structural and functional studies. https://www.jove.com/v/54273 707 2016-08-01T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57061.jpg A Facile Protocol to Generate Site-Specifically Acetylated Proteins in Escherichia Coli Genetic code expansion serves as a powerful tool to study a wide range of biological processes, including protein acetylation. Here we demonstrate a facile protocol to exploit this technique for generating homogeneously acetylated proteins at specific sites in Escherichia coli cells. https://www.jove.com/v/57061 668 2017-12-09T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57069.jpg Optimizing the Genetic Incorporation of Chemical Probes into GPCRs for Photo-crosslinking Mapping and Bioorthogonal Chemistry in Live Mammalian Cells A facile fluorescence assay is presented to evaluate the efficiency of amino-acyl-tRNA-synthetase/tRNA pairs incorporating non-canonical amino-acids (ncAAs) into proteins expressed in mammalian cells. The application of ncAAs to study G-protein coupled receptors (GPCRs) is described, including photo-crosslinking mapping of binding sites and bioorthogonal GPCR labeling on live cells. https://www.jove.com/v/57069 842 2018-04-09T14:30:00+00:00 JoVE no https://visualize.jove.com/28419785-internal-noise-estimates-correlate-with-autistic-traits monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11041.jpg Self-Discrepancy Theory One influential perspective on what motivates people's behavior is detailed in Tory Higgin's self-discrepancy theory (Higgins, 1987). He proposed that people hold disagreeing internal representations of themselves that lead to different emotional states. According to the self-discrepancy theory, people hold beliefs about what they’re really like—their actual self—as well as what they would ideally like to be—their ideal self—and what they think they should be—their ought self. Ideally,... https://www.jove.com/v/11041 165 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18167.jpg Environmental Influences on Intelligence Despite the strong genetic influence on traits like intelligence, environmental factors significantly shape outcomes. For example, while over 90% of height variation is due to genetic differences, environmental factors such as nutrition also have a notable impact. Similarly, for intelligence, changes in a child's surroundings can significantly alter their IQ. Research shows that enriched environments boost children's academic success and help them develop key cognitive skills. Children from... https://www.jove.com/v/18167 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18627.jpg Modeling in Therapy Modeling, a key technique in therapy, uses observational learning to help clients acquire and practice new skills by watching therapists demonstrate desired behaviors. This approach, rooted in Albert Bandura's concept of vicarious learning, plays a significant role in therapeutic interventions for various psychological conditions, including social anxiety, ADHD, and depression. Participant Modeling Participant modeling involves therapists demonstrating calm and effective behaviors in situations... https://www.jove.com/v/18627 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/19610.jpg Autism Spectrum Disorder Autism spectrum disorder (ASD) is a neurodevelopmental condition marked by persistent deficits in social communication and interaction alongside restrictive and repetitive behaviors or interests. ASD is sometimes accompanied by intellectual impairment. These core symptoms manifest differently among individuals, ranging from mild to severe. The disorder's complexity extends beyond its clinical presentation, encompassing a diverse range of biological, cognitive, and sociocultural influences.<br... https://www.jove.com/v/19610 79 JoVE no https://cloudfront.jove.com/files/ftp_upload/19930/19930_article_thumb_19930.jpg Dark Triad and Person Perception Person perception is influenced by both external behaviors and the observer’s internal characteristics, including personality traits. Individuals with dark personality traits, comprising psychopathy, Machiavellianism, and narcissism — collectively known as the dark triad – exhibit manipulative and exploitative tendencies in social contexts. These traits affect how they perceive others and how they are perceived.The Role of Dark Personality Traits in Person PerceptionBlack et al. (2014) explored... https://www.jove.com/v/19930 89 2025-09-18T10:24:08+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19942/19942_article_thumb_19942.jpg Implicit Personality Theories Implicit personality theory explains how individuals make assumptions about the relationships between personality traits, behaviors, and character types. When people learn that someone possesses a particular trait, they tend to infer the presence of other related characteristics, forming a cohesive impression. This cognitive shortcut plays a crucial role in social interactions and interpersonal judgments.Central Traits and Their InfluenceSolomon Asch's seminal 1946 study highlighted the power... https://www.jove.com/v/19942 83 2025-09-18T10:23:59+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52677.jpg Testing Sensory and Multisensory Function in Children with Autism Spectrum Disorder We describe how to implement a battery of behavioral tasks to examine the processing and integration of sensory stimuli in children with ASD. The goal is to characterize individual differences in temporal processing of simple auditory and visual stimuli and relate these to higher order perceptual skills like speech perception. https://www.jove.com/v/52677 553 2015-04-22T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58694.jpg Comparing Eye-tracking Data of Children with High-functioning ASD, Comorbid ADHD, and of a Control Watching Social Videos This is a qualitative comparative case study analysis of eye-tracking data on the first moments of social video scenes as viewed by three participants: one with autism spectrum disorder, one with comorbid attention deficit-hyperactive disorder, and one neurotypical control. https://www.jove.com/v/58694 332 2018-12-07T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66846.jpg Strategies for Assessing Autistic-Like Behaviors in Mice Rodent models are valuable tools for studying core behaviors related to autism spectrum disorder (ASD). In this article, we expound on two behavioral tests for modeling the core features of ASD in mice: self-grooming, which assesses repetitive behavior, and the three-chamber social interaction test, which documents social impairments. https://www.jove.com/v/66846 458 2024-09-20T13:20:00+00:00 JoVE no https://visualize.jove.com/28422669-bioinspired-approach-to-modeling-retinal-ganglion-cells-using-system-identification-techniques monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/55229.jpg Single-cell RNA-Seq of Defined Subsets of Retinal Ganglion Cells Here, we present a combinatorial approach for classifying neuronal cell types prior to isolation and for the subsequent characterization of single-cell transcriptomes. This protocol optimizes the preparation of samples for successful RNA Sequencing (RNA-Seq) and describes a methodology designed specifically for the enhanced understanding of cellular diversity. https://www.jove.com/v/55229 686 2017-05-22T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63792.jpg Computational Modeling of Retinal Neurons for Visual Prosthesis Research - Fundamental Approaches We summarize a workflow to computationally model a retinal neuron's behaviors in response to electrical stimulation. The computational model is versatile and includes automation steps that are useful in simulating a range of physiological scenarios and anticipating the outcomes of future in vivo/in vitro studies. https://www.jove.com/v/63792 650 2022-06-21T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65503.jpg LipidUNet-Machine Learning-Based Method of Characterization and Quantification of Lipid Deposits Using iPSC-Derived Retinal Pigment Epithelium Degenerative eye diseases that affect the retinal pigment epithelium layer of the eye have monogenic and polygenic origins. Several disease models and a software application, LipidUNet, have been developed to study mechanisms of disease, as well as potential therapeutic interventions. https://www.jove.com/v/65503 376 2023-07-28T19:50:00+00:00 JoVE no https://visualize.jove.com/28574731-why-gene-editors-like-crisprcas-may-be-a-game-changer-for-neuroweapons monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10806.jpg What is Genetic Engineering? Overview Genetic engineering is the process of modifying an organism’s DNA to introduce new, desirable traits. Many organisms, from bacteria to plants and animals, have been genetically modified for academic, medical, agricultural, and industrial purposes. While genetic engineering has definite benefits, ethical concerns surround modifying humans and our food supply. Scientists can Deliberately Modify an Organism’s Genome Genetic engineering is possible because the genetic code—the way... https://www.jove.com/v/10806 49 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10817.jpg CRISPR Genome editing technologies allow scientists to modify an organism’s DNA via the addition, removal, or rearrangement of genetic material at specific genomic locations. These types of techniques could potentially be used to cure genetic disorders such as hemophilia and sickle cell anemia. One popular and widely used DNA-editing research tool that could lead to safe and effective cures for genetic disorders is the CRISPR-Cas9 system. CRISPR-Cas9 stands for Clustered Regularly Interspaced Short... https://www.jove.com/v/10817 119 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11567.jpg Homologous Recombination The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the... https://www.jove.com/v/11567 151 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11631.jpg CRISPR and crRNAs Bacteria and archaea are susceptible to viral infections just like eukaryotes; therefore, they have developed a unique adaptive immune system to protect themselves. Clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins (CRISPR-Cas) are present in more than 45% of known bacteria and 90% of known archaea. The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different... https://www.jove.com/v/11631 173 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10817.jpg CRISPR Genome editing technologies allow scientists to modify an organism’s DNA via the addition, removal, or rearrangement of genetic material at specific genomic locations. These types of techniques could potentially be used to cure genetic disorders such as hemophilia and sickle cell anemia. One popular and widely used DNA-editing research tool that could lead to safe and effective cures for genetic disorders is the CRISPR-Cas9 system. CRISPR-Cas9 stands for Clustered Regularly Interspaced Short... https://www.jove.com/v/12032 119 JoVE no https://cloudfront.jove.com/files/ftp_upload/19594/19594_article_thumb_19594.jpg CRISPR/Cas9 Genome Editing The CRISPR-Cas system serves as a bacterial defense mechanism against invading genetic elements such as viruses and plasmids, forming the foundation for its adaptation as a powerful genome-editing tool. Originally discovered in prokaryotes, this system has been repurposed to revolutionize genetic engineering across a wide range of organisms, including plants, animals, and humans. The core component, Cas9, is an endonuclease derived from Streptococcus pyogenes, capable of introducing... https://www.jove.com/v/19594 88 2025-06-12T16:30:53+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55903.jpg Selection-dependent and Independent Generation of CRISPR/Cas9-mediated Gene Knockouts in Mammalian Cells Recent advances in the ability to genetically manipulate somatic cell lines hold great potential for basic and applied research. Here, we present two approaches for CRISPR/Cas9 generated knockout production and screening in mammalian cell lines, with and without the use of selectable markers. https://www.jove.com/v/55903 695 2017-06-16T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57350.jpg Enhanced Genome Editing with Cas9 Ribonucleoprotein in Diverse Cells and Organisms Utilizing a preassembled Cas9 ribonucleoprotein complex (RNP) is a powerful method for precise, efficient genome editing. Here, we highlight its utility across a broad range of cells and organisms, including primary human cells and both classic and emerging model organisms. https://www.jove.com/v/57350 591 2018-05-25T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60685.jpg A New Toolkit for Evaluating Gene Functions using Conditional Cas9 Stabilization Here, we describe a genome-editing tool based on the temporal and conditional stabilization of clustered regularly interspaced short palindromic repeat- (CRISPR-) associated protein 9 (Cas9) under the small molecule, Shield-1. The method can be used for cultured cells and animal models. https://www.jove.com/v/60685 500 2021-09-02T20:00:00+00:00 JoVE no https://visualize.jove.com/28814023-representing-high-dimensional-data-to-intelligent-prostheses-and-other-wearable-assistive-robots-a-first-comparison-of-tile-coding-and-selective-kanerva-coding monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3007.jpg Haptic/Graphic Rehabilitation: Integrating a Robot into a Virtual Environment Library and Applying it to Stroke Therapy Recently, a vast amount of prospects have come available for human-robot interactive systems. In this paper we outline the integration of a new robotic device with open source software that can rapidly make possible a library of interactive functionality. We then outline a clinical application for a neurorehabilitation... https://www.jove.com/v/3007 824 14700 2011-08-08T13:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14059.jpg Functional Classification of Joints Functional Classification of Joints The functional classification of joints is determined by the amount of mobility between the adjacent bones. Joints are functionally classified as a synarthrosis or immobile joint, an amphiarthrosis or slightly moveable joint, or as a diarthrosis, a freely moveable joint. Fibrous and cartilaginous joints can be functionally classified as either synarthroses or amphiarthroses, whereas all synovial joints are classified as diarthroses. Synarthrosis An immobile... https://www.jove.com/v/14059 69 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52341.jpg Closed-loop Neuro-robotic Experiments to Test Computational Properties of Neuronal Networks In this paper, an experimental framework to perform closed-loop experiments is presented, in which information processing (i.e., coding and decoding) and learning of neuronal assemblies are studied during the continuous interaction with a robotic... https://www.jove.com/v/52341 678 10900 2015-03-02T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52968.jpg A Structured Rehabilitation Protocol for Improved Multifunctional Prosthetic Control: A Case Study As prosthetic development moves towards the goal of natural control, harnessing amputees’ inherent ability to learn new motor skills may enable proficiency. This manuscript describes a structured rehabilitation protocol, which includes imitation, repetition, and reinforcement learning strategies, for improved multifunctional prosthetic... https://www.jove.com/v/52968 418 10300 2015-11-06T16:00:00+00:00 JoVE no https://visualize.jove.com/28820319-a-to-i-rna-editing-thinking-beyond-the-single-nucleotide monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10802.jpg RNA Splicing Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded... https://www.jove.com/v/10802 92 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10804.jpg RNA Interference RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated. This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used... https://www.jove.com/v/10804 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11623.jpg RNA Editing RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or modification. The extent of RNA editing varies from a few hundred bases, in mitochondrial DNA of trypanosomes, to a just single base, in nuclear genes of mammals. Even a single base change in the pre-mRNA can convert a codon for one amino acid into the codon for another amino acid or a stop codon. This type of re-coding can significantly affect the... https://www.jove.com/v/11623 143 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10804.jpg RNA Interference RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated. This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used... https://www.jove.com/v/11627 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12022.jpg RNA-seq RNA sequencing, or RNA-Seq, is a high-throughput sequencing technology used to study the transcriptome of a cell. Transcriptomics helps to interpret the functional elements of a genome and identify the molecular constituents of an organism. Additionally, it also helps in understanding the development of an organism and the occurrence of diseases. Before the discovery of RNA-seq, microarray-based methods and Sanger sequencing were used for transcriptome analysis. However, while microarray-based... https://www.jove.com/v/12022 201 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14371.jpg Nucleic Acid Structure The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group on the ribose's second carbon and a hydrogen on the deoxyribose's second carbon. The phosphate residue attaches to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms a 5′ to 3′ phosphodiester linkage. DNA Structure DNA has a double-helix structure. The... https://www.jove.com/v/14371 85 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51712.jpg RNA Catalyst as a Reporter for Screening Drugs against RNA Editing in Trypanosomes A highly sensitive ribozyme-based assay, applicable to high-throughput screening of chemicals targeting the unique process of RNA editing in trypanosomatid pathogens, is described in this paper. Inhibitors can be used as tools for hypothesis-driven analysis of the RNA editing process and ultimately as therapeutics. https://www.jove.com/v/51712 559 2014-07-22T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57350.jpg Enhanced Genome Editing with Cas9 Ribonucleoprotein in Diverse Cells and Organisms Utilizing a preassembled Cas9 ribonucleoprotein complex (RNP) is a powerful method for precise, efficient genome editing. Here, we highlight its utility across a broad range of cells and organisms, including primary human cells and both classic and emerging model organisms. https://www.jove.com/v/57350 591 2018-05-25T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63591.jpg A Nonsequencing Approach for the Rapid Detection of RNA Editing Rapid detection and reliable quantification of RNA editing events at a genomic scale remain challenging and currently rely on direct RNA sequencing methods. The protocol described here uses microtemperature gradient gel electrophoresis (µTGGE) as a simple, quick, and portable method of detecting RNA editing. https://www.jove.com/v/63591 530 2022-04-21T13:20:00+00:00 JoVE no https://visualize.jove.com/29032428-usability-operations-on-touch-mobile-devices-for-users-with-autism monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3675.jpg Eye Tracking Young Children with Autism Eye tracking has long been used to study gaze patterns in typically-developing individuals, but recent technological advancements have made its use with clinical populations, including autism, more feasible. While eye-tracking young children with autism can offer insight into early symptom manifestations, it involves methodological challenges. Suggestions for best practices are provided. https://www.jove.com/v/3675 543 2012-03-27T19:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15075.jpg Design Example: Resistive Touchscreen A device engineer plays a crucial role in designing user interfaces for mobile devices. One such interface is the resistive touchscreen, which fundamentally consists of two metallic layers: a flexible upper layer and a rigid lower layer, separated by a narrow gap. The high resistance between these two layers is a key characteristic of this design. When a user touches the screen, the two layers make contact at a specific point known as the touchpoint. This contact reduces the resistance between... https://www.jove.com/v/15075 74 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15177.jpg Design Example The innovation of touch-tone telephony revolutionized the telecommunications industry by replacing the traditional rotary dial with a dual-tone multi-frequency (DTMF) signaling system. This system uses a matrix-style keypad with buttons arranged in four rows and three columns, creating 12 distinct signals each assigned to a pair of frequencies. Each button press results in a simultaneous generation of two sinusoidal tones – one from a low-frequency group (697 to 941 Hz) and one from a... https://www.jove.com/v/15177 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/19610.jpg Autism Spectrum Disorder Autism spectrum disorder (ASD) is a neurodevelopmental condition marked by persistent deficits in social communication and interaction alongside restrictive and repetitive behaviors or interests. ASD is sometimes accompanied by intellectual impairment. These core symptoms manifest differently among individuals, ranging from mild to severe. The disorder's complexity extends beyond its clinical presentation, encompassing a diverse range of biological, cognitive, and sociocultural influences.<br... https://www.jove.com/v/19610 79 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52286.jpg Practical Methodology of Cognitive Tasks Within a Navigational Assessment Children who have complex communication needs can benefit from the use of a speech-generating device (SGD). Cognitive skills were identified as having an impact on the ability to navigate between levels of SGDs. This protocol describes the steps needed for Speech-language Pathologists to assess cognitive skills and navigational abilities. https://www.jove.com/v/52286 319 2015-06-01T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52677.jpg Testing Sensory and Multisensory Function in Children with Autism Spectrum Disorder We describe how to implement a battery of behavioral tasks to examine the processing and integration of sensory stimuli in children with ASD. The goal is to characterize individual differences in temporal processing of simple auditory and visual stimuli and relate these to higher order perceptual skills like speech perception. https://www.jove.com/v/52677 553 2015-04-22T22:00:00+00:00 JoVE no https://visualize.jove.com/29280160-when-micrornas-meet-rna-editing-in-cancer-a-nucleotide-change-can-make-a-difference monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10801.jpg MicroRNAs MicroRNA (miRNA) are short, regulatory RNA transcribed from introns—non-coding regions of a gene—or intergenic regions—stretches of DNA present between genes. Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA ends... https://www.jove.com/v/10801 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11623.jpg RNA Editing RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or modification. The extent of RNA editing varies from a few hundred bases, in mitochondrial DNA of trypanosomes, to a just single base, in nuclear genes of mammals. Even a single base change in the pre-mRNA can convert a codon for one amino acid into the codon for another amino acid or a stop codon. This type of re-coding can significantly affect the... https://www.jove.com/v/11623 143 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10801.jpg MicroRNAs MicroRNA (miRNA) are short, regulatory RNA transcribed from introns—non-coding regions of a gene—or intergenic regions—stretches of DNA present between genes. Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA ends... https://www.jove.com/v/11628 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12033.jpg Experimental RNAi RNA interference (RNAi) is a cellular mechanism that inhibits gene expression by suppressing its transcription or activating the RNA degradation process. The mechanism was discovered by Andrew Fire and Craig Mello in 1998 in plants. Today, it is observed in almost all eukaryotes, including protozoa, flies, nematodes, insects, parasites, and mammals. This precise cellular mechanism of gene silencing has been developed into a technique that provides an efficient way to identify and determine the... https://www.jove.com/v/12033 135 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13151.jpg MicroRNAs MicroRNA (miRNA) are short, regulatory RNA transcribed from introns (non-coding regions of a gene) or intergenic regions (stretches of DNA present between genes). Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself, forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA... https://www.jove.com/v/13151 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14371.jpg Nucleic Acid Structure The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group on the ribose's second carbon and a hydrogen on the deoxyribose's second carbon. The phosphate residue attaches to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms a 5′ to 3′ phosphodiester linkage. DNA Structure DNA has a double-helix structure. The... https://www.jove.com/v/14371 85 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63591.jpg A Nonsequencing Approach for the Rapid Detection of RNA Editing Rapid detection and reliable quantification of RNA editing events at a genomic scale remain challenging and currently rely on direct RNA sequencing methods. The protocol described here uses microtemperature gradient gel electrophoresis (µTGGE) as a simple, quick, and portable method of detecting RNA editing. https://www.jove.com/v/63591 530 2900 2022-04-21T12:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63704.jpg CRISPR Gene Editing Tool for MicroRNA Cluster Network Analysis This protocol describes a high-throughput clustered regularly interspaced short palindromic repeats (CRISPR) gene editing workflow for microRNA cluster network analysis that allows the rapid generation of a panel of genetically modified cell lines carrying unique miRNA cluster member deletion combinations as large as 35 kb within a single... https://www.jove.com/v/63704 640 2700 2022-04-25T12:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68617.jpg MicroRNA Amplification and Recognition through Locked-nucleic-acid In situ Hybridization as A Novel Detection and Quantification Method The protocol describes a tandem immunofluorescence hybridization assay with formalin-fixed paraffin-embedded tissue to detect and quantify microRNA and multiplexed proteins simultaneously. https://www.jove.com/v/68617 546 259 2025-10-07T11:30:00+00:00 JoVE no https://visualize.jove.com/29381146-australias-continental-scale-acoustic-tracking-database-and-its-automated-quality-control-process monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12789.jpg Sound Intensity The loudness of a sound source is related to how energetically the source is vibrating, consequently making the molecules of the propagation medium vibrate. To measure the loudness of a source, the physical quantity of interest is the intensity. This is defined as the energy emitted per unit of time per unit of area perpendicular to the sound wave's propagation direction. Since the total energy is greater if the source vibrates for a longer duration and over a larger area, dividing the emitted... https://www.jove.com/v/12789 58 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12790.jpg Sound Intensity Level Humans perceive sound by hearing. The human ear helps sound waves reach the brain, which then interprets the waves and creates the perception of hearing. The loudness of the environment in which a person is located determines whether they can distinguish between different sound sources. The human ear can perceive an extensive range of sound intensity, necessitating the use of the logarithmic scale to define a physical quantity—the intensity level. It is a ratio of two intensities and hence a... https://www.jove.com/v/12790 53 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14724.jpg Sound as Pressure Waves Sound waves, which are longitudinal waves, can be modeled as the displacement amplitude varying as a function of the spatial and temporal coordinates. As a column of the medium is displaced, its successive columns are also displaced. As the successive displacements differ relatively, a pressure difference with the surrounding pressure is created. The gauge pressure varies across the medium. The pressure fluctuation depends on the difference in displacements between the successive points in the... https://www.jove.com/v/14724 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14763.jpg Quality Control Quality control is one of the three cyclical quality assurance activities that help keep a system under statistical control. Typical quality control activities include creating quality control charts, conducting proficiency testing, and documenting and archiving results. Quality control helps track data, visualize trends, and identify variations, making it easier to detect deviations that may affect the accuracy of an analysis. One way to do this is by generating a quality control chart, which... https://www.jove.com/v/14763 65 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14764.jpg Quality Assurance Quality assurance is the overarching term used to describe the activities employed to ensure the proper performance of a system. These activities can be classified into three categories: quality control, quality assessment, and internal corrective measures. Typically, these activities work cyclically: quality control is performed before and during the analysis, while quality assessment occurs during and after the investigation. Internal corrective measures are implemented based on the findings... https://www.jove.com/v/14764 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14768.jpg Instrument Calibration Instrument calibration is essential for ensuring that instruments produce accurate and consistent results. It is vital in manufacturing, healthcare, testing laboratories, and scientific research. Calibration processes are specific to each instrument and help enhance data accuracy. Each instrument has a unique calibration process tailored to its design and function to improve data accuracy. Analytical Balance Calibration An analytical balance measures mass and requires regular calibration to... https://www.jove.com/v/14768 72 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66313.jpg Foreign Accent and Forensic Speaker Identification in Voice Lineups: The Influence of Acoustic Features Based on Prosody This research aimed to make a comparison between L1-L2-English and L1-L2 Portuguese to check how much the effect of a foreign accent accounts for both metrics and prosodic-acoustic parameters, as well as for the choice of the target voice in a voice lineup. https://www.jove.com/v/66313 549 2024-09-27T19:35:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/70048.jpg An Automated System for Sound Localization Testing in Hearing-Impaired Listeners This protocol introduces an automated sound localization testing system with precise loudspeaker placement and integrated response analysis, validated in normal-hearing participants and participants with single-sided deafness. It provides a reproducible method to assess spatial hearing and supports functional classification using the International Classification of Functioning, Disability and Health (ICF) framework. https://www.jove.com/v/70048 472 2026-03-13T20:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/70479.jpg Enhancing an Avian Sound Recognition Model's Detection Precision via Logistic Regression of Large Acoustic Datasets: A Case Study of the European Robin ( Erithacus rubecula ) The goal of this protocol is to determine species- and site-specific confidence score thresholds using logistic regression to improve detection precision in large acoustic datasets processed with automated acoustic recognition software. https://www.jove.com/v/70479 655 2026-04-12T03:00:00+00:00 JoVE no https://visualize.jove.com/29401361-a-multiple-imputation-forward-bridging-approach-to-address-changes-in-the-classification-of-asian-raceethnicity-on-the-us-death-certificate monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10777.jpg Multiple Allele Traits The Concept of Multiple Allelism Multiple allelism describes genes that exist in three or more allelic forms. Although diploid organisms, like humans, normally possess only two alleles of each gene, there are multiple alleles of many (if not most) human genes present in a population. Blood type is one example of multiple allelism. There are three alleles for blood type (HBB gene) in humans: IA, IB, and i. Incomplete Dominance Sickle cell anemia, which is caused by a mutation in the gene... https://www.jove.com/v/10777 109 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11069.jpg Stereotypes, Prejudice, and Discrimination Humans are very diverse and although we share many similarities, we also have many differences. The social groups we belong to help form our identities (Tajfel, 1974). These differences may be difficult for some people to reconcile, which may lead to prejudice toward people who are different. Prejudice is a negative attitude and feeling toward an individual based solely on one’s membership in a particular social group (Allport, 1954; Brown, 2010). Prejudice is common against people who are... https://www.jove.com/v/11069 175 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12019.jpg RACE - Rapid Amplification of cDNA Ends Rapid Amplification of cDNA Ends, or RACE, is one of the most effective methods to obtain a full-length cDNA from an mRNA sequence between a known internal region to the unknown sequence at the 5’ or 3’ end. The unknown region is cloned in the cDNA by a gene-specific primer that binds the known end, and a hybrid primer that attaches a predefined anchor sequence to the unknown end of the cDNA. The sequence in between is amplified by PCR with an anchor primer and a gene-specific primer. Since the... https://www.jove.com/v/12019 155 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17606.jpg Confounding in Epidemiological Studies Confounding in statistical epidemiology represents a pivotal challenge, referring to the distortion in the perceived relationship between an exposure and an outcome due to the presence of a third variable, known as a confounder. This variable is associated with both the exposure and the outcome but is not a direct link in their causal chain. Its presence can lead to erroneous interpretations of the exposure's effect, either exaggerating or underestimating the true association. This phenomenon... https://www.jove.com/v/17606 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17607.jpg Strategies for Assessing and Addressing Confounding Confounding is a critical issue in epidemiological studies, often leading to misleading conclusions about associations between exposures and outcomes. It occurs when the relationship between the exposure and the outcome is mixed with the effects of other factors that influence the outcome. Given that, addressing confounding is of high importance for drawing accurate inferences in research. Confounding can be addressed at both the design phase of a study and through analytical methods after data... https://www.jove.com/v/17607 85 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59825.jpg Inverse Probability of Treatment Weighting (Propensity Score) using the Military Health System Data Repository and National Death Index When randomized controlled trials are not feasible, a comprehensive health care data source like the Military Health System Data Repository provides an attractive alternative for retrospective analyses. Incorporating mortality data from the national death index and balancing differences between groups using propensity weighting helps reduce biases inherent in retrospective designs. https://www.jove.com/v/59825 415 2020-01-08T20:00:00+00:00 JoVE no https://visualize.jove.com/29849544-a-machine-learning-approach-to-the-detection-of-pilots-reaction-to-unexpected-events-based-on-eeg-signals monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/50602.jpg Simultaneous Scalp Electroencephalography (EEG), Electromyography (EMG), and Whole-body Segmental Inertial Recording for Multi-modal Neural Decoding Development of an effective brain-machine-interface (BMI) system for restoration and rehabilitation of bipedal locomotion requires accurate decoding of user's intent. Here we present a novel experimental protocol and data collection technique for simultaneous non-invasive acquisition of neural activity, muscle activity, and whole-body kinematics during various locomotion tasks and conditions. https://www.jove.com/v/50602 685 2013-07-26T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53406.jpg A Novel Experimental and Analytical Approach to the Multimodal Neural Decoding of Intent During Social Interaction in Freely-behaving Human Infants This protocol presents a novel methodology for the neural decoding of intent from freely-behaving infants during unscripted social interaction with an actor. Neural activity is acquired using non-invasive high-density active scalp electroencephalography (EEG). Kinematic data is collected with inertial measurement units and supplemented with synchronized video recording. https://www.jove.com/v/53406 674 2015-10-04T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65931.jpg Artificial Intelligence-Based System for Detecting Attention Levels in Students This paper proposes an artificial intelligence-based system to automatically detect whether students are paying attention to the class or are distracted. This system is designed to help teachers maintain students' attention, optimize their lessons, and dynamically introduce modifications in order for them to be more engaging. https://www.jove.com/v/65931 397 2023-12-15T22:10:00+00:00 JoVE no https://visualize.jove.com/29883264-content-analysis-to-locate-assistive-technology-in-queenslands-motor-injury-insurance-rehabilitation-legislation-and-guidelines monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/62896.jpg Therapy Interventions for Upper Limb Amputees Undergoing Selective Nerve Transfers This work presents a protocol to enhance prosthetic function after selective nerve transfer surgery. Rehabilitation interventions include patient information and selection, support of wound healing, cortical re-activation of sensory-motor areas of the upper limb, training of selective muscle activation, prosthetic handling in daily life, and regular follow-up assessments. https://www.jove.com/v/62896 479 2021-10-29T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65736.jpg Setup for the Quantitative Assessment of Motion and Muscle Activity During a Virtual Modified Box and Block Test The protocol described here aims to enhance the quantitative evaluation of upper limb deficits, with the goal of developing additional technology for remote assessment both in the clinic and at home. Virtual reality and biosensor technologies are combined with standard clinical techniques to provide insights into the functioning of the neuromuscular system. https://www.jove.com/v/65736 246 2024-01-12T13:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66938.jpg Enhancing Upper Limb Function and Motor Skills Post-Stroke Through an Upper Limb Rehabilitation Robot This protocol describes an upper limb rehabilitation robot that provides intelligent feedback through four modes. These modes enhance upper limb function and flexibility, thereby improving patients' quality of life. https://www.jove.com/v/66938 289 2024-09-06T13:50:00+00:00 JoVE no https://visualize.jove.com/29995920-a-machine-learning-method-to-monitor-chinas-aids-epidemics-with-data-from-baidu-trends monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2312.jpg Comprehensive & Cost Effective Laboratory Monitoring of HIV/AIDS: an African Role Model Anti-retroviral therapy to treat HIV/AIDS is monitored in South Africa on a large scale. Flow cytometry is combined for haematology (CD45), immunology (CD4) and viral-load linked CD38 assay. Recorded at NHLS-SA laboratories, Johannesburg, these modern methods are cost-efficient with heightened local internal quality control, serving as role-models for resource-limited diagnostics. https://www.jove.com/v/2312 1436 2010-11-01T00:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17611.jpg Steps in Outbreak Investigation In the ever-evolving field of public health, statistical analysis serves as a cornerstone for understanding and managing disease outbreaks. By leveraging various statistical tools, health professionals can predict potential outbreaks, analyze ongoing situations, and devise effective responses to mitigate impact. For that to happen, there are a few possible stages of the analysis: Predicting Outbreaks Predictive analytics, a branch of statistics, uses historical data, algorithmic models, and... https://www.jove.com/v/17611 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17624.jpg Statistical Software for Data Analysis and Clinical Trials Statistical software is pivotal in data analysis and clinical trials by providing tools to analyze data, draw conclusions, and make predictions. These software packages range from simple data management applications to complex analytical platforms, supporting various statistical tests, models, and simulation techniques. Their significance lies in their ability to handle vast amounts of data with precision and efficiency, enabling researchers to validate hypotheses, identify trends, and make... https://www.jove.com/v/17624 72 JoVE no https://cloudfront.jove.com/files/ftp_upload/40806/40806_article_thumb_40806.jpg Infectious Diseases and Their Occurrence Infectious diseases appear in populations through various transmission patterns, influenced by pathogen characteristics, population immunity, environmental conditions, and social behavior. Understanding these patterns is essential for effective public health surveillance and intervention. These categories—sporadic, outbreak, epidemic, pandemic, and endemic—help frame the nature and scope of disease events.Sporadic diseases occur irregularly and infrequently, without a predictable temporal or... https://www.jove.com/v/40806 88 2026-03-12T20:36:14+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51242.jpg An Affordable HIV-1 Drug Resistance Monitoring Method for Resource Limited Settings Drug resistance testing for HIV-1 infected individuals failing antiretroviral therapy (ART) can guide future therapies and improve treatment outcomes. Optimizing individual and population health outcomes in high HIV prevalence but resource-limited settings will ultimately require affordable and accessible drug resistance genotyping and interpretation methods. https://www.jove.com/v/51242 1197 2014-03-30T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68222.jpg Machine Learning-Based Cough Tone Classification: Diagnostic Exploration of Chronic Obstructive Pulmonary Disease and Respiratory Tract Infections This study effectively accomplished the automated classification of two distinct categories by acquiring cough sound data from patients diagnosed with chronic obstructive pulmonary disease (COPD) and respiratory tract infections (RTI), utilizing an integration of speech signal processing techniques and machine learning algorithms. https://www.jove.com/v/68222 382 2025-09-19T20:45:00+00:00 JoVE no https://visualize.jove.com/30066646-beyond-the-one-way-anova-for-omics-data monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13619.jpg What is an ANOVA? The Analysis of Variance or ANOVA is a statistical test developed by Ronald Fisher in 1918. It is performed on three or more samples to check for equality between their means. Before performing ANOVA, one must ensure that the samples used for this analysis have three crucial characteristics or statistical assumptions. The first assumption states that the samples should be drawn from normally distributed samples, while the second requires that all the drawn samples should be randomly and... https://www.jove.com/v/13619 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13620.jpg One-Way ANOVA One-way ANOVA analyzes more than three samples categorized by one factor. For example, it can compare the average mileage of sports bikes. Here, the data is categorized by one factor - the company. However, one-way ANOVA cannot be used to simultaneously compare the sample mean of three or more samples categorized by two factors. An example of two factors would be sports bikes from different companies driven in different terrains, such as a desert or snowy landscape. Here, two-way ANOVA is used... https://www.jove.com/v/13620 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13621.jpg One-Way ANOVA: Equal Sample Sizes One-Way ANOVA can be performed on three or more samples with equal or unequal sample sizes. When one-way ANOVA is performed on two datasets with samples of equal sizes, it can be easily observed that the computed F statistic is highly sensitive to the sample mean. Different sample means can result in different values for the variance estimate: variance between samples. This is because the variance between samples is calculated as the product of the sample size and the variance between the... https://www.jove.com/v/13621 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13624.jpg Two-Way ANOVA The two-way ANOVA is an extension of the one-way ANOVA. It is a statistical test performed on three or more samples categorized by two factors - a row factor and a column factor. Ronald Fischer mentioned it in 1925 in his book 'Statistical Methods for Researchers.' The two-way ANOVA analysis initially begins by stating the null hypothesis that there is an interaction effect between the two factors of a dataset. This effect can be visualized using line segments formed by joining the means for... https://www.jove.com/v/13624 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16481.jpg Statistical Methods to Analyze Parametric Data: ANOVA Analysis of Variance, or ANOVA, is a powerful statistical technique used to analyze parametric data, primarily in research and experimental studies. It's designed to compare the means of two or more groups, assisting researchers in identifying any significant differences between these group means. There are two main types of ANOVA based on the complexity of the analysis: one-way and two-way. One-way ANOVA is applied when a single independent variable or factor is scrutinized. It compares the... https://www.jove.com/v/16481 72 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17358.jpg What is ANOVA? The Analysis of Variance or ANOVA is a statistical test developed by Ronald Fisher in 1918. It is performed on three or more samples to check for equality between their means. Before performing ANOVA, one must ensure that the samples used for this analysis have three crucial characteristics or statistical assumptions. The first assumption states that the samples should be drawn from normally distributed samples, while the second requires that all the drawn samples be randomly and independently... https://www.jove.com/v/17358 73 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54410.jpg The Terroir Concept Interpreted through Grape Berry Metabolomics and Transcriptomics This article describes the application of untargeted metabolomics, transcriptomics and multivariate statistical analysis to grape berry transcripts and metabolites in order to gain insight into the terroir concept, i.e., the impact of the environment on berry quality traits. https://www.jove.com/v/54410 782 2016-10-05T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59980.jpg Microbiota Analysis Using Two-step PCR and Next-generation 16S rRNA Gene Sequencing Described here is a simplified standard operating procedure for microbiome profiling using 16S rRNA metagenomic sequencing and analysis using freely available tools. This protocol will help researchers who are new to the microbiome field as well as those requiring updates on methods to achieve bacterial profiling at a higher resolution. https://www.jove.com/v/59980 682 2019-10-15T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66659.jpg Application of Unsupervised Multi-Omic Factor Analysis to Uncover Patterns of Variation and Molecular Processes Linked to Cardiovascular Disease We present a flexible, extendible Jupyter-lab-based workflow for the unsupervised analysis of complex multi-omics datasets that combines different pre-processing steps, estimation of the multi-omics factor analysis model, and several downstream analyses. https://www.jove.com/v/66659 531 2024-09-20T20:10:00+00:00 JoVE no https://visualize.jove.com/30149445-prodromal-alzheimers-disease-demonstrates-increased-errors-at-a-simple-and-automated-anti-saccade-task monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15204.jpg Alzheimer's Disease: Overview Alzheimer's Disease (AD) is a continually advancing neurodegenerative disorder, distinguished by escalating memory loss, cognitive dysfunction, and dementia. The disease unfolds in three stages: preclinical, mild cognitive impairment (MCI), and dementia. Its onset is insidious, and the progression gradual, with the cause not well explained by other disorders. The clinical diagnosis of AD hinges on the presence of memory and other cognitive impairments. Biomarkers, such as changes in Aβ and tau... https://www.jove.com/v/15204 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/40940/40940_article_thumb_40940.jpg Alzheimer Disease l: Introduction Alzheimer disease is a chronic, progressive, and irreversible neurodegenerative disorder and the most common cause of dementia in older adults. It leads to gradual neuronal loss, causing cognitive decline, behavioral changes, and loss of functional independence.Risk Factors and EtiologyThe disease is multifactorial. Age is the strongest risk factor, with prevalence doubling every 5 years after age 65. Genetic factors include mutations in genes such as APP, PSEN1, and PSEN2, which are associated... https://www.jove.com/v/40940 89 2026-04-15T17:31:37+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40941/40941_article_thumb_40941.jpg Alzheimer Disease ll: Pathophysiology Alzheimer disease involves structural changes in the brain that begin long before symptoms appear. The most distinctive features are extracellular neuritic plaques and intracellular neurofibrillary tangles.Neuritic plaques form in the cerebral cortex and around blood vessels. These plaques contain a dense core of beta-amyloid (Aβ)—a toxic protein fragment that clumps outside neurons. The core is surrounded by damaged neuronal extensions, as well as reactive astrocytes and microglia. Abnormal... https://www.jove.com/v/40941 83 2026-04-13T21:37:54+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53308.jpg Intracerebroventricular Injection of Amyloid-β Peptides in Normal Mice to Acutely Induce Alzheimer-like Cognitive Deficits The amyloid-β (Aβ)-injected animal model enables the administration of a defined quantity and species of Aβ fragments and reduces individual differences within each study group. This protocol describes the intracerebroventricular (ICV) injection of Aβ without stereotactic instruments, enabling the production of Alzheimer-like behavioral abnormalities in normal mice. https://www.jove.com/v/53308 481 2016-03-16T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55523.jpg Assessment of Spontaneous Alternation, Novel Object Recognition and Limb Clasping in Transgenic Mouse Models of Amyloid-β and Tau Neuropathology Described here is a staged, behavioral screening approach that can be used to screen for compounds that exhibit in vivo efficacy on cognitive and functional motor behaviors in transgenic mouse models of β-amyloidosis and tauopathy. These methods are optimized to screen compounds for activity in short-term and working memory tasks. https://www.jove.com/v/55523 602 2017-05-28T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58009.jpg Automated, Long-term Behavioral Assay for Cognitive Functions in Multiple Genetic Models of Alzheimer's Disease, Using IntelliCage This paper describes a protocol for cognitive assessments for genetic models of the Alzheimer's disease using the IntelliCage system, which is a high throughput automated behavioral monitoring system with operant conditioning. https://www.jove.com/v/58009 406 2018-08-04T22:00:00+00:00 JoVE no https://visualize.jove.com/30297207-nonlinear-biochemistry-of-nucleosome-detergents monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11531.jpg The Nucleosome DNA in a human cell is almost 2m long and it is packed inside a tiny nucleus that is only a few microns in diameter. The level of compaction of DNA inside the nucleus is astonishing. It is organized into several sequentially higher levels of compaction to fit into such a tiny space. The most compact form of DNA is a chromosome that can be seen under a microscope in a dividing cell. DNA is wound twice around a protein complex called histone core, that consist of 8 histone proteins. This complex... https://www.jove.com/v/11531 153 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11532.jpg The Nucleosome Core Particle Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins. The paradox Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA... https://www.jove.com/v/11532 130 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11533.jpg Nucleosome Remodeling Nucleosomes are the basic units of chromatin compaction. Each nucleosome consists of the DNA bound tightly around a histone core, which makes the DNA inaccessible to DNA binding proteins such as DNA polymerase and RNA polymerase. Hence, the fundamental problem is to ensure access to DNA when appropriate, despite the compact and protective chromatin structure. Nucleosome remodeling complex Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes... https://www.jove.com/v/11533 174 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12227.jpg Restriction Enzymes Restriction enzymes are bacterial enzymes used to cut DNA in a sequence-specific manner. To cleave DNA, they bind to specific palindromic sequences called restriction sites. Such palindromic DNA sequences or inverted repeats are commonly found in regions of functional significance, such as the origin of replication, gene operator sites, and regions containing transcription termination signals. The host bacteria protect their own genomic DNA from these enzymes by methylating these sites. Some... https://www.jove.com/v/12227 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13914.jpg The Nucleosome Human DNA is almost two meters long. However, it is compressed inside a tiny nucleus measuring only a few microns in diameter. To make this degree of compaction possible, DNA is organized into several sequential levels so that it can fit into such a tiny space. The most compact form of DNA is a chromosome that can be seen under a microscope in a dividing cell. In a chromosome, DNA is wound twice around a protein complex called a histone octamer core, which consists of 8 histone proteins. This... https://www.jove.com/v/13914 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14746.jpg The Nucleosome Core Particle Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins. Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during... https://www.jove.com/v/14746 72 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51721.jpg Biochemical Assays for Analyzing Activities of ATP-dependent Chromatin Remodeling Enzymes Here we describe biochemical assays that can be used to characterize ATP-dependent chromatin remodeling enzymes for their abilities to 1) catalyze ATP-dependent nucleosome sliding, 2) engage with nucleosome substrates, and 3) hydrolyze ATP in a nucleosome- or DNA-dependent manner. https://www.jove.com/v/51721 614 2014-10-25T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55349.jpg Reconstitution of Nucleosomes with Differentially Isotope-labeled Sister Histones This protocol describes the reconstitution of nucleosomes containing differentially isotope-labeled sister histones. At the same time, asymmetrically post-translationally modified nucleosomes can be generated after using a premodified histone copy. These preparations can be readily used to study modification crosstalk mechanisms, simultaneously on both sister histones, by using high-resolution NMR spectroscopy. https://www.jove.com/v/55349 566 2017-03-26T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66579.jpg In Situ Nucleosome Assembly for Single-Molecule Correlative Force and Fluorescence Microscopy This article presents a detailed experimental procedure for reconstituting nucleosome-containing DNA tethers for single-molecule correlative force and fluorescence microscopy. It further describes several downstream experiments that can be conducted to visualize the binding behavior of chromatin-interacting proteins and analyze changes in the physical properties of nucleosomes. https://www.jove.com/v/66579 358 2024-09-06T19:50:00+00:00 JoVE no https://visualize.jove.com/30734227-systematic-review-of-mirna-as-biomarkers-in-alzheimers-disease monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10801.jpg MicroRNAs MicroRNA (miRNA) are short, regulatory RNA transcribed from introns—non-coding regions of a gene—or intergenic regions—stretches of DNA present between genes. Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA ends... https://www.jove.com/v/10801 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13151.jpg MicroRNAs MicroRNA (miRNA) are short, regulatory RNA transcribed from introns (non-coding regions of a gene) or intergenic regions (stretches of DNA present between genes). Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself, forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA... https://www.jove.com/v/13151 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15204.jpg Alzheimer's Disease: Overview Alzheimer's Disease (AD) is a continually advancing neurodegenerative disorder, distinguished by escalating memory loss, cognitive dysfunction, and dementia. The disease unfolds in three stages: preclinical, mild cognitive impairment (MCI), and dementia. Its onset is insidious, and the progression gradual, with the cause not well explained by other disorders. The clinical diagnosis of AD hinges on the presence of memory and other cognitive impairments. Biomarkers, such as changes in Aβ and tau... https://www.jove.com/v/15204 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/40940/40940_article_thumb_40940.jpg Alzheimer Disease l: Introduction Alzheimer disease is a chronic, progressive, and irreversible neurodegenerative disorder and the most common cause of dementia in older adults. It leads to gradual neuronal loss, causing cognitive decline, behavioral changes, and loss of functional independence.Risk Factors and EtiologyThe disease is multifactorial. Age is the strongest risk factor, with prevalence doubling every 5 years after age 65. Genetic factors include mutations in genes such as APP, PSEN1, and PSEN2, which are associated... https://www.jove.com/v/40940 89 2026-04-15T10:31:37+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40941/40941_article_thumb_40941.jpg Alzheimer Disease ll: Pathophysiology Alzheimer disease involves structural changes in the brain that begin long before symptoms appear. The most distinctive features are extracellular neuritic plaques and intracellular neurofibrillary tangles.Neuritic plaques form in the cerebral cortex and around blood vessels. These plaques contain a dense core of beta-amyloid (Aβ)—a toxic protein fragment that clumps outside neurons. The core is surrounded by damaged neuronal extensions, as well as reactive astrocytes and microglia. Abnormal... https://www.jove.com/v/40941 83 2026-04-13T14:37:54+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51172.jpg Cerebrospinal Fluid MicroRNA Profiling Using Quantitative Real Time PCR We describe a protocol of real time PCR to profile microRNAs in the cerebrospinal fluid (CSF). With the exception of RNA extraction protocols, the procedure can be extended to RNA extracted from other body fluids, cultured cells, or tissue specimens. https://www.jove.com/v/51172 566 2014-01-22T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66552.jpg Biomarker Identification for Gender Specificity of Alzheimer's Disease Based on the Glial Transcriptome Profiles This study analyzed single-nuclei transcriptomes of thirty-three individuals with Alzheimer's disease (AD), revealing sex-specific DEGs in glial cells. Functional enrichment analysis highlighted synaptic, neural, and hormone-related pathways. Key genes, namely NLGN4Y and its regulators, were identified, and potential therapeutic candidates for gender-specific AD were proposed. https://www.jove.com/v/66552 262 2024-05-20T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68617.jpg MicroRNA Amplification and Recognition through Locked-nucleic-acid In situ Hybridization as a Novel Detection and Quantification Method The protocol describes a tandem immunofluorescence hybridization assay with formalin-fixed paraffin-embedded tissue to detect and quantify microRNA and multiplexed proteins simultaneously. https://www.jove.com/v/68617 546 2025-10-07T12:30:00+00:00 JoVE no https://visualize.jove.com/30972504-how-amdahls-law-limits-the-performance-of-large-artificial-neural-networks-why-the-functionality-of-full-scale-brain-simulation-on-processor-based-simulators-is-limited monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13779.jpg Ampere's Law: Problem-Solving Ampere's law states that for any closed looped path, the line integral of the magnetic field along the path equals the vacuum permeability times the current enclosed in the loop. If the fingers of the right hand curl along the direction of the integration path, the current in the direction of the thumb is considered positive. The current opposite to the thumb direction is considered negative. Specific steps need to be considered while calculating the symmetric magnetic field distribution using... https://www.jove.com/v/13779 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14207.jpg Ampere-Maxwell's Law: Problem-Solving A parallel-plate capacitor with capacitance C, whose plates have area A and separation distance d, is connected to a resistor R and a battery of voltage V. The current starts to flow at t = 0. What is the displacement current between the capacitor plates at time t? From the properties of the capacitor, what is the corresponding real current? To solve the problem, we can use the equations from the analysis of an RC circuit and Maxwell's version of Ampère's law. For the first part of the problem,... https://www.jove.com/v/14207 77 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52341.jpg Closed-loop Neuro-robotic Experiments to Test Computational Properties of Neuronal Networks In this paper, an experimental framework to perform closed-loop experiments is presented, in which information processing (i.e., coding and decoding) and learning of neuronal assemblies are studied during the continuous interaction with a robotic body. https://www.jove.com/v/52341 678 2015-03-02T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57292.jpg Targeting Neuronal Fiber Tracts for Deep Brain Stimulation Therapy Using Interactive, Patient-Specific Models The goal of this project is to develop an interactive, patient-specific modeling pipeline to simulate the effects of deep brain stimulation in near real-time and provide meaningful feedback as to how these devices influence neural activity in the brain. https://www.jove.com/v/57292 854 2018-08-12T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64930.jpg Large Scale Energy Efficient Sensor Network Routing Using a Quantum Processor Unit This study provides a method to use a quantum processor unit to compute the routes for various traffic dynamics that work to outperform classical methods in literature to maximize network lifetime. https://www.jove.com/v/64930 330 2023-09-08T21:35:00+00:00 JoVE no https://visualize.jove.com/30974780-technology-to-support-aging-in-place-older-adults-perspectives monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12957.jpg Current Trends in Nursing I Current trends in nursing include: The changes that have shaped the profession. Guided legislation. The functioning of the present healthcare system. With an increase in the aging population worldwide, it is crucial to train nurses from all healthcare settings to identify approaches that enable older adults to live independently. Nurses also provide essential care and education to manage multiple chronic conditions and ensure the elderly in long-term care receive optimal care and... https://www.jove.com/v/12957 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12958.jpg Current Trends in Nursing II Trends in nursing are multifactorial and associated with changes in society, within the nursing profession, and in other professions. Notably, telehealth and remote nursing contribute to successful healthcare delivery for numerous patients and help reduce stress for nurses due to nursing shortages. Nurses can reach patients, monitor their conditions, and interact with them using computers, audio, visual accessories, and telephones—for example, remote patient monitoring systems. Likewise,... https://www.jove.com/v/12958 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14124.jpg Documentation in Long-Term and Home Healthcare Setting Documentation in long-term care facilities and home healthcare settings is crucial for ensuring continuous, coordinated, and comprehensive care for patients. Each setting has its specific documentation processes and tools: Long-Term Care Facilities • Purpose: Documentation in long-term care facilities is critical for interprofessional resident assessment and planning. It ensures that all aspects of a resident's care - from medical needs to daily living assistance - are thoroughly monitored... https://www.jove.com/v/14124 89 JoVE no https://cloudfront.jove.com/files/ftp_upload/17195/17195_article_thumb_17195.jpg Drug Dosing: Geriatric Patients Elderly individuals encompass a diverse population with varying degrees of age-related physiological changes. Defining the elderly presents challenges, as the geriatric population is often arbitrarily categorized as individuals older than 65. However, many individuals in this group lead active and healthy lives, with an increasing number surpassing 85 years and falling into the older elderly category. Physiological changes associated with aging impact performance capacity and homeostatic... https://www.jove.com/v/17195 75 2025-10-03T14:00:27+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18559.jpg Cognitive Development During Adulthood Cognitive development continues throughout adulthood, undergoing significant shifts across early, middle, and late stages. Individual transition occurs from adolescent idealism to pragmatic and adaptable thinking in early adulthood. During this period, individuals learn to integrate personal beliefs with the recognition that other perspectives are equally valid. Exposure to the complexities of modern society, diverse experiences, and higher education contribute to this adaptive thought process,... https://www.jove.com/v/18559 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18575.jpg Aging Aging is a complex biological phenomenon influenced by various processes that affect cellular and systemic functions. Several prominent theories attempt to explain its mechanisms, highlighting cellular limitations, oxidative damage, and hormonal changes as central factors in aging. Cellular Clock Theory The cellular clock theory posits that the human lifespan is closely tied to the finite capacity of cells to divide, a phenomenon governed by telomeres, which are protective caps at the ends of... https://www.jove.com/v/18575 86 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56942.jpg Methodology for Establishing a Community-Wide Life Laboratory for Capturing Unobtrusive and Continuous Remote Activity and Health Data Unobtrusive sensors and pervasive computing technology incorporated into the daily home life of older adults enables meaningful health and activity changes to be recorded continuously for months to years, providing ecologically valid, high frequency, multi-domain data for research or clinical use. https://www.jove.com/v/56942 681 2018-07-27T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58834.jpg Using a Real-Time Locating System to Measure Walking Activity Associated with Wandering Behaviors Among Institutionalized Older Adults This paper discusses the use of a continuous and objective real-time locating system to measure walking activity associated with wandering behaviors, focusing on older adults with cognitive impairment. Walking activity is measured by walking distance, sustained walking distance, and sustained gait speed. Also assessed are gait quality and balance ability. https://www.jove.com/v/58834 253 2019-02-08T21:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60330.jpg A Computerized Functional Skills Assessment and Training Program Targeting Technology Based Everyday Functional Skills This training protocol uses computerized training to teach technology-related everyday functional skills. These skills include financial skills, travel and transit, as well as medication management. https://www.jove.com/v/60330 451 2020-02-13T20:00:00+00:00 JoVE no https://visualize.jove.com/31075879-predictors-of-seniors-interest-in-assistive-applications-on-smartphones-evidence-from-a-population-based-survey-in-slovenia monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/53004.jpg Evaluation of a Smartphone-based Human Activity Recognition System in a Daily Living Environment A standardized evaluation method was developed for Wearable Mobility Monitoring Systems (WMMS) that includes continuous activities in a realistic daily living environment. Testing with a series of daily living activities can decrease activity recognition sensitivity; therefore, realistic testing circuits are encouraged for valid evaluation of WMMS performance. https://www.jove.com/v/53004 409 2015-12-11T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54659.jpg Video Movement Analysis Using Smartphones (ViMAS): A Pilot Study This manuscript describes the method to test the concurrent validity of kinematic measures recorded by the smartphone application in comparison to a 3D motion capture system in the sagittal plane. This protocol will enable clinicians to set up smartphones for video capture of human movement. https://www.jove.com/v/54659 471 2017-03-14T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56942.jpg Methodology for Establishing a Community-Wide Life Laboratory for Capturing Unobtrusive and Continuous Remote Activity and Health Data Unobtrusive sensors and pervasive computing technology incorporated into the daily home life of older adults enables meaningful health and activity changes to be recorded continuously for months to years, providing ecologically valid, high frequency, multi-domain data for research or clinical use. https://www.jove.com/v/56942 681 2018-07-27T12:30:00+00:00 JoVE no https://visualize.jove.com/31213967-diagnosis-of-alzheimers-disease-via-multi-modality-3d-convolutional-neural-network monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15204.jpg Alzheimer's Disease: Overview Alzheimer's Disease (AD) is a continually advancing neurodegenerative disorder, distinguished by escalating memory loss, cognitive dysfunction, and dementia. The disease unfolds in three stages: preclinical, mild cognitive impairment (MCI), and dementia. Its onset is insidious, and the progression gradual, with the cause not well explained by other disorders. The clinical diagnosis of AD hinges on the presence of memory and other cognitive impairments. Biomarkers, such as changes in Aβ and tau... https://www.jove.com/v/15204 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/40940/40940_article_thumb_40940.jpg Alzheimer Disease l: Introduction Alzheimer disease is a chronic, progressive, and irreversible neurodegenerative disorder and the most common cause of dementia in older adults. It leads to gradual neuronal loss, causing cognitive decline, behavioral changes, and loss of functional independence.Risk Factors and EtiologyThe disease is multifactorial. Age is the strongest risk factor, with prevalence doubling every 5 years after age 65. Genetic factors include mutations in genes such as APP, PSEN1, and PSEN2, which are associated... https://www.jove.com/v/40940 89 2026-04-15T17:31:37+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40941/40941_article_thumb_40941.jpg Alzheimer Disease ll: Pathophysiology Alzheimer disease involves structural changes in the brain that begin long before symptoms appear. The most distinctive features are extracellular neuritic plaques and intracellular neurofibrillary tangles.Neuritic plaques form in the cerebral cortex and around blood vessels. These plaques contain a dense core of beta-amyloid (Aβ)—a toxic protein fragment that clumps outside neurons. The core is surrounded by damaged neuronal extensions, as well as reactive astrocytes and microglia. Abnormal... https://www.jove.com/v/40941 83 2026-04-13T21:37:54+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40948/40948_article_thumb_40948.jpg Dementia l: Introduction Dementia is an acquired, progressive syndrome characterized by a decline in multiple cognitive domains severe enough to impair daily functioning and reduce independence. Although memory loss is a central feature, the diagnosis requires additional deficits involving language, executive function, visuospatial skills, judgment, calculation, or abstract reasoning. These cognitive impairments reflect underlying neurodegenerative or vascular processes that gradually disrupt neuronal networks... https://www.jove.com/v/40948 82 2026-04-13T23:55:59+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50319.jpg Identification of Disease-related Spatial Covariance Patterns using Neuroimaging Data Multivariate techniques including principal component analysis (PCA) have been used to identify signature patterns of regional change in functional brain images. We have developed an algorithm to identify reproducible network biomarkers for the diagnosis of neurodegenerative disorders, assessment of disease progression, and objective evaluation of treatment effects in patient populations. https://www.jove.com/v/50319 867 2013-06-26T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65910.jpg DeepOmicsAE: Representing Signaling Modules in Alzheimer's Disease with Deep Learning Analysis of Proteomics, Metabolomics, and Clinical Data DeepOmicsAE is a workflow centered on the application of a deep learning method (i.e., an autoencoder) to reduce the dimensionality of multi-omics data, providing a foundation for predictive models and signaling modules representing multiple layers of omics data. https://www.jove.com/v/65910 587 2023-12-15T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67574.jpg Hybrid PET/MRI Imaging of Alzheimer's Disease Based on 18 F-AV-1451 This protocol describes the use of 18F-AV-1451 PET/MRI to reveal tau pathology and neurodegeneration, aiding neurologists in diagnosing Alzheimer's disease, assessing its severity, and gaining insights into its progression and underlying pathological mechanisms. https://www.jove.com/v/67574 317 2025-04-18T20:00:00+00:00 JoVE no https://visualize.jove.com/31295467-over-expression-of-mir-34a-induces-rapid-cognitive-impairment-and-alzheimers-disease-like-pathology monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10801.jpg MicroRNAs MicroRNA (miRNA) are short, regulatory RNA transcribed from introns—non-coding regions of a gene—or intergenic regions—stretches of DNA present between genes. Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA ends... https://www.jove.com/v/10801 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13151.jpg MicroRNAs MicroRNA (miRNA) are short, regulatory RNA transcribed from introns (non-coding regions of a gene) or intergenic regions (stretches of DNA present between genes). Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself, forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA... https://www.jove.com/v/13151 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15204.jpg Alzheimer's Disease: Overview Alzheimer's Disease (AD) is a continually advancing neurodegenerative disorder, distinguished by escalating memory loss, cognitive dysfunction, and dementia. The disease unfolds in three stages: preclinical, mild cognitive impairment (MCI), and dementia. Its onset is insidious, and the progression gradual, with the cause not well explained by other disorders. The clinical diagnosis of AD hinges on the presence of memory and other cognitive impairments. Biomarkers, such as changes in Aβ and tau... https://www.jove.com/v/15204 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/40940/40940_article_thumb_40940.jpg Alzheimer Disease l: Introduction Alzheimer disease is a chronic, progressive, and irreversible neurodegenerative disorder and the most common cause of dementia in older adults. It leads to gradual neuronal loss, causing cognitive decline, behavioral changes, and loss of functional independence.Risk Factors and EtiologyThe disease is multifactorial. Age is the strongest risk factor, with prevalence doubling every 5 years after age 65. Genetic factors include mutations in genes such as APP, PSEN1, and PSEN2, which are associated... https://www.jove.com/v/40940 89 2026-04-15T10:31:37+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40941/40941_article_thumb_40941.jpg Alzheimer Disease ll: Pathophysiology Alzheimer disease involves structural changes in the brain that begin long before symptoms appear. The most distinctive features are extracellular neuritic plaques and intracellular neurofibrillary tangles.Neuritic plaques form in the cerebral cortex and around blood vessels. These plaques contain a dense core of beta-amyloid (Aβ)—a toxic protein fragment that clumps outside neurons. The core is surrounded by damaged neuronal extensions, as well as reactive astrocytes and microglia. Abnormal... https://www.jove.com/v/40941 83 2026-04-13T14:37:54+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40948/40948_article_thumb_40948.jpg Dementia l: Introduction Dementia is an acquired, progressive syndrome characterized by a decline in multiple cognitive domains severe enough to impair daily functioning and reduce independence. Although memory loss is a central feature, the diagnosis requires additional deficits involving language, executive function, visuospatial skills, judgment, calculation, or abstract reasoning. These cognitive impairments reflect underlying neurodegenerative or vascular processes that gradually disrupt neuronal networks... https://www.jove.com/v/40948 82 2026-04-13T16:55:59+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53089.jpg Motor and Hippocampal Dependent Spatial Learning and Reference Memory Assessment in a Transgenic Rat Model of Alzheimer's Disease with Stroke To investigate the co-morbid Alzheimer's disease (AD) and stroke condition in a novel model, three behavior tasks are described that assess both motor control and cognitive behaviors. These tasks include the beam-walk task, cylinder task and Morris water maze. https://www.jove.com/v/53089 585 2016-03-22T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54868.jpg Quantitative 3D In Silico Modeling (q3DISM) of Cerebral Amyloid-beta Phagocytosis in Rodent Models of Alzheimer's Disease We developed a methodology for quantitative 3D in silico modeling (q3DISM) of cerebral amyloid-β (Aβ) phagocytosis by mononuclear phagocytes in rodent models of Alzheimer's disease. This method can be generalized for the quantitation of virtually any phagocytic event in vivo. https://www.jove.com/v/54868 573 2016-12-26T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57123.jpg Novel Passive Clearing Methods for the Rapid Production of Optical Transparency in Whole CNS Tissue Here, we present two novel methodologies, psPACT and mPACT, for achieving maximal optical transparency and subsequent microscopic analysis of tissue vasculature in the intact rodent whole CNS. https://www.jove.com/v/57123 374 2018-05-08T14:00:00+00:00 JoVE no https://visualize.jove.com/31555764-applications-of-machine-learning-approaches-in-emergency-medicine-a-review-article monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17611.jpg Steps in Outbreak Investigation In the ever-evolving field of public health, statistical analysis serves as a cornerstone for understanding and managing disease outbreaks. By leveraging various statistical tools, health professionals can predict potential outbreaks, analyze ongoing situations, and devise effective responses to mitigate impact. For that to happen, there are a few possible stages of the analysis: Predicting Outbreaks Predictive analytics, a branch of statistics, uses historical data, algorithmic models, and... https://www.jove.com/v/17611 78 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58382.jpg Predicting Treatment Response to Image-Guided Therapies Using Machine Learning: An Example for Trans-Arterial Treatment of Hepatocellular Carcinoma Intra-arterial therapies are the standard of care for patients with hepatocellular carcinoma who cannot undergo surgical resection. A method for predicting response to these therapies is proposed. The technique uses pre-procedural clinical, demographic, and imaging information to train machine learning models capable of predicting response prior to... https://www.jove.com/v/58382 249 8600 2018-10-10T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61235.jpg Machine Learning Algorithms for Early Detection of Bone Metastases in an Experimental Rat Model This protocol was designed to train a machine learning algorithm to use a combination of imaging parameters derived from magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) in a rat model of breast cancer bone metastases to detect early metastatic disease and predict subsequent progression to... https://www.jove.com/v/61235 435 7400 2020-08-16T13:00:00+00:00 JoVE no https://visualize.jove.com/31607442-over-view-of-major-traumatic-injury-in-australia-implications-for-trauma-system-design monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16369.jpg Flail Chest-II Managing flail chest, a condition characterized by a segment of the chest wall moving independently from the rest of the thoracic cage, requires a comprehensive approach. It includes a thorough assessment of the patient's condition, a diagnostic evaluation to determine the extent of the injury, and the implementation of appropriate medical interventions tailored to the individual's needs. Assessment: 1. Clinical Evaluation: History: • Nurses obtain a detailed history of the traumatic event,... https://www.jove.com/v/16369 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/40929/40929_article_thumb_40929.jpg Traumatic Brain Injury l: Introduction DefinitionTraumatic brain injury, or TBI, is a disturbance of normal brain function induced by an external mechanical force, such as a direct blow to the head or a penetrating injury. It can affect both brain structure and function, producing a wide range of clinical outcomes. TBI is a heterogeneous condition, meaning its effects may differ based on the type, location, and severity of the injury.Basis of ClassificationTBI is classified based on severity, injury mechanism, or pathophysiology. In... https://www.jove.com/v/40929 88 2026-04-13T16:56:05+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40932/40932_article_thumb_40932.jpg Spinal Cord Injury ll: Pathophysiology Spinal cord injury progresses through two interconnected phases: primary injury and secondary injury.Primary InjuryPrimary injury happens at the moment of trauma and involves immediate mechanical damage to the spinal cord.Compression happens when broken vertebrae, herniated discs, or accumulating blood (such as a hematoma) press directly against the spinal cord, distorting its normal shape and function. In cases of contusion, the cord is bruised by a blunt force (like penetrating injuries or... https://www.jove.com/v/40932 74 2026-04-15T10:51:51+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60027.jpg Murine Model of Controlled Cortical Impact for the Induction of Traumatic Brain Injury Here we describe a protocol for the induction of murine traumatic brain injury via an open-head controlled cortical... https://www.jove.com/v/60027 301 11000 2019-08-16T14:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64592.jpg Assessing Changes in Synaptic Plasticity Using an Awake Closed-Head Injury Model of Mild Traumatic Brain Injury Here, it is demonstrated how an awake closed-head injury model can be used for examining the effects of repeated mild traumatic brain injury (r-mTBI) on synaptic plasticity in the hippocampus. The model replicates important features of r-mTBI in patients and is used in conjunction with in vitro... https://www.jove.com/v/64592 589 3600 2023-01-20T12:55:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66948.jpg Author Spotlight: Developing Precise and Clinically Relevant Models for Studying Secondary Degeneration in Traumatic Optic Neuropathy This protocol describes a custom overpressure air system designed to induce closed-system central nervous system (CNS) injuries in mice, including ocular, brain, and spinal cord traumas. The goal of this protocol is to provide a framework for researchers to easily adapt and expand the system for their unique CNS trauma studies. https://www.jove.com/v/66948 242 1500 2024-11-29T13:20:00+00:00 JoVE no https://visualize.jove.com/31608978-cell-autonomous-impact-of-polysialic-acid-producing-enzyme-st8sia2-on-developmental-migration-and-distribution-of-cortical-interneurons monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2583.jpg Migratory Behavior of Cells Generated in Ganglionic Eminence Cultures Time lapse imaging of 3D tissue culture allows studying migratory behavior of individual cells originating from ganglionic eminence in reaction to fractionated protein extract from cerebral... https://www.jove.com/v/2583 394 10400 2011-04-21T11:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12260.jpg Cytoskeletal Coordination in Cell Migration A migrating cell changes its shape during the cyclic events of attachment and detachment from the substratum and repositions the cell organelles correspondingly. These complex events are orchestrated by the dynamic cytoskeletal network comprising actin filaments, intermediate filaments, and microtubules. Cytoskeletal crosstalk — the direct and indirect communication between the different components — is crucial for this coordination. Direct communication involves various linker proteins that... https://www.jove.com/v/12260 92 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53282.jpg Stable and Efficient Genetic Modification of Cells in the Adult Mouse V-SVZ for the Analysis of Neural Stem Cell Autonomous and Non-autonomous Effects Here we describe a procedure based on the use of lentiviral particles for the long-term genetic modification of neural stem cells and/or their adjacent ependymal cells in the adult ventricular-subventricular neurogenic niche which allows the separate analysis of cell autonomous and non-autonomous, niche-dependent effects on neural stem... https://www.jove.com/v/53282 528 9700 2016-02-17T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57526.jpg Ex Utero Electroporation and Organotypic Slice Cultures of Embryonic Mouse Brains for Live-Imaging of Migrating GABAergic Interneurons Here, we provide a low-cost and reliable method to generate electroporated brain organotypic slice cultures from mouse embryos suitable for confocal microscopy and live-imaging... https://www.jove.com/v/57526 590 10400 2018-04-20T15:00:00+00:00 JoVE no https://visualize.jove.com/31683885-securing-iot-based-rfid-systems-a-robust-authentication-protocol-using-symmetric-cryptography monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11927.jpg Protection and Deprotection of Alcohols and Phenols This lesson delves into the concept of protection and deprotection of a functional group fundamental to synthetic organic chemistry. These phenomena are explained in the context of aliphatic and aromatic alcohols. Protection It defines a protecting group as the masking agent to make the more reactive species inert to a given set of conditions. This concept is depicted via the illustration of liquid flow through different outlets in an assembly of pipes. The analogy helps to understand the role... https://www.jove.com/v/11927 151 7900 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14123.jpg Legal Guidelines for Documentation The legal guidelines for nursing documentation are essential for ensuring accurate, professional, and ethical recording of patient care. The guidelines are discussed here: • Avoid Retaliatory or Critical Comments: Documenting disrespectful comments about patients or other professionals can reflect poorly on the quality of care and the professionalism of the healthcare environment. This kind of documentation can be interpreted as unprofessional and may have legal implications. ... https://www.jove.com/v/14123 66 1900 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14130.jpg Ethical Standards I The American Nurses Association (ANA) created and implemented the first nationally accepted Code of Ethics for Nurses with Interpretive Statements. The Code of Ethics is a living document regularly updated by the ANA and establishes an ethical standard that is non-negotiable for nurses in all roles and settings. The Code of Ethics provisions outline the nurse's duty to the patient, the healthcare team, the profession, and society. The Code's fundamental principles include advocacy,... https://www.jove.com/v/14130 85 1400 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16029.jpg Signal and System A signal x(t) is a set of data or a time function representing a variable of interest. Signals typically convey information about a phenomenon, such as atmospheric temperature, humidity, human voice, television images, a dog's bark, or birdsongs. More generally, a signal can be a function of more than one independent variable. For instance, images depend on horizontal and vertical positions and can be regarded as two-dimensional signals. However, this text will focus on one-dimensional... https://www.jove.com/v/16029 86 1500 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16162.jpg Radial System Protection Radial systems employ time-delay overcurrent relays to reduce load interruptions. When a fault occurs, the nearest breaker opens first, while upstream breakers remain closed due to longer delay settings. This approach ensures minimal disruption to the rest of the system. In a radial system with a fault downstream of the third breaker, ideally, only the third breaker will open, isolating the fault and interrupting the load connected beyond it. The second breaker has a longer delay setting,... https://www.jove.com/v/16162 83 401 JoVE no https://cloudfront.jove.com/files/ftp_upload/19879/19879_article_thumb_19879.jpg Role-Based Identity Role-based identities are central to understanding how individuals navigate social environments by adopting distinct self-conceptions aligned with various societal roles. These identities are not fixed traits but are constructed through personal actions and the social feedback individuals receive in context-specific interactions. Each social role, such as student, teacher, or friend, carries a set of expectations and norms that influence how people think, feel, and behave within that... https://www.jove.com/v/19879 81 155 2025-09-18T10:24:23+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64930.jpg Large Scale Energy Efficient Sensor Network Routing Using a Quantum Processor Unit This study provides a method to use a quantum processor unit to compute the routes for various traffic dynamics that work to outperform classical methods in literature to maximize network lifetime. https://www.jove.com/v/64930 330 2023-09-08T14:35:00+00:00 JoVE no https://visualize.jove.com/31684791-erroneous-computer-based-interpretations-of-atrial-fibrillation-and-atrial-flutter-in-a-swedish-primary-health-care-setting monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13286.jpg Pulse rhythm Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding. Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle... https://www.jove.com/v/13286 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15276.jpg Disturbances in Heart Rhythm Arrhythmia or dysrhythmia refers to an abnormal heart rhythm caused by a defect in the heart's conduction system. It can cause the heart to beat irregularly, too quickly, or too slowly, leading to symptoms like chest pain, shortness of breath, and fainting. Factors such as stress, caffeine, alcohol, nicotine, cocaine, certain drugs, congenital defects, diseases, and electrolyte abnormalities can trigger arrhythmias. Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart... https://www.jove.com/v/15276 89 2025-07-29T16:29:05+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17879.jpg ECG Interpretation of Arrhythmias I: Sinus Arrhythmias Arrhythmias are disturbances in the heart's rhythm that lead to abnormal heartbeats. These irregularities can originate from different parts of the heart and are classified based on their origin and nature. Types of Arrhythmias Sinus Node Arrhythmias Sinus Bradycardia: Originating from the sinoatrial (SA) node, sinus bradycardia involves slower impulses, resulting in a heart rate of less than 60 beats per minute (bpm). Causes include sleep, vagal stimulation, beta-blockers, hypothyroidism, and... https://www.jove.com/v/17879 76 JoVE no https://cloudfront.jove.com/files/ftp_upload/17942/17942_article_thumb_17942.jpg Dysrhythmias V: Evaluating Dysrhythmias Dysrhythmias, also known as arrhythmias, are disturbances in the heart's rhythm that range from benign to life-threatening. A thorough evaluation is crucial for appropriate management and involves a comprehensive medical history, physical examination, and various diagnostic tests.Medical HistorySymptoms: Collect detailed information on palpitations, dizziness, syncope, chest pain, and fatigue. Note their onset, frequency, and triggers.Previous Cardiac Issues: Document any history of heart... https://www.jove.com/v/17942 90 2025-06-19T16:36:46+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17943/17943_article_thumb_17943.jpg Dysrhythmias VI: Management of Dysrhythmias Dysrhythmia management involves a multifaceted approach, incorporating pharmacological treatments, medical procedures, surgical interventions, lifestyle modifications, and patient education.Pharmacological ManagementAntiarrhythmic Drugs:Class I (Sodium Channel Blockers): This class includes quinidine and procainamide, which reduce the speed of impulse conduction in the heart, stabilize the cardiac membrane, and control arrhythmias. Quinidine and procainamide are Class IA agents that prolong the... https://www.jove.com/v/17943 85 2025-06-19T16:37:04+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/18437/18437_article_thumb_18437.jpg ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias Arrhythmia is a condition characterized by an irregular heart rhythm, with ECG changes that differ based on its origin and nature. The types of arrhythmias discussed below include atrial, junctional, and ventricular arrhythmias.Atrial ArrhythmiasPremature Atrial Complexes (PACs): PACs are early atrial beats caused by stress, caffeine, alcohol, electrolyte imbalances, hypoxia, hyperthyroidism, or certain medications (e.g., bronchodilators and decongestants). The ECG shows early P waves with an... https://www.jove.com/v/18437 85 2025-06-19T16:15:27+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54170.jpg Continuous IV Infusion is the Choice Treatment Route for Arginine-vasopressin Receptor Blocker Conivaptan in Mice to Study Stroke-evoked Brain Edema Our studies have revealed that the beneficial effects of conivaptan are dependent on the method of delivery after experimental stroke in mice. We have developed a research protocol for delivery of the receptor blocker via IV catheter on stroke-evoked brain edema formation in mice. https://www.jove.com/v/54170 524 9200 2016-09-01T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55518.jpg Improving Strength, Power, Muscle Aerobic Capacity, and Glucose Tolerance through Short-term Progressive Strength Training Among Elderly People The effect of short-term resistance training on elderly people was investigated through the simultaneous use of several methods. Compared to a control group, many improvements were seen, including on muscle aerobic capacity, glucose tolerance, strength, power, and muscle quality (i.e., protein involved in cell signaling and muscle fiber type... https://www.jove.com/v/55518 779 13000 2017-07-05T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66878.jpg Surgical Approach and Complications of Stand-alone Lateral Trans-Psoas Interbody Fusion Interbody fusion of the lumbar spine can be achieved surgically using different techniques. Minimally invasive techniques, including lateral interbody fusion, have been developed within recent decades to reduce rates of complications and allow for quicker patient recovery. We provide insight into stand-alone lateral trans-psoas interbody fusion, highlighting potential complications and... https://www.jove.com/v/66878 330 1400 2025-02-14T12:40:00+00:00 JoVE no https://visualize.jove.com/31747428-temporal-trends-in-intracerebral-hemorrhage-evidence-from-the-austrian-stroke-unit-registry monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40914/40914_article_thumb_40914.jpg Stroke: Introduction and Types A stroke is an acute neurological event caused by the sudden disruption of cerebral blood flow, leading to rapid loss of neuronal function. Neurons depend on continuous oxygen and glucose supply, so even brief interruptions can cause irreversible injury within minutes. Strokes are classified into ischemic and hemorrhagic types.Ischemic StrokeIschemic strokes are most common and occur due to arterial occlusion, depriving brain tissue of oxygen and nutrients. This leads to energy failure, ionic... https://www.jove.com/v/40914 89 2026-04-15T17:54:32+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40917/40917_article_thumb_40917.jpg Hemorrhagic Stroke l: Introduction A hemorrhagic stroke is an acute neurological event that occurs when a weakened cerebral blood vessel ruptures, allowing blood to accumulate within or around the brain. The sudden release of blood forms a focal hematoma that increases intracranial pressure, displaces neural tissue, and can obstruct cerebrospinal fluid pathways. These effects may be compounded by intraventricular extension of the hemorrhage, cerebral edema, or compression of adjacent structures, all of which contribute to... https://www.jove.com/v/40917 77 2026-04-13T23:56:01+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40918/40918_article_thumb_40918.jpg Hemorrhagic Stroke ll: Pathophysiology A hemorrhagic stroke develops when a cerebral blood vessel ruptures, allowing blood to escape into the surrounding brain tissue, as in intracerebral hemorrhage (ICH), or into the subarachnoid space, as in subarachnoid hemorrhage (SAH). Because the skull is a rigid compartment, the sudden presence of extravascular blood rapidly increases intracranial pressure and compresses adjacent neural structures, leading to immediate tissue injury and impaired cerebral perfusion.Mass Effect and Primary... https://www.jove.com/v/40918 89 2026-04-13T21:37:26+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52978.jpg A Thrombotic Stroke Model Based On Transient Cerebral Hypoxia-ischemia Thromboembolic stroke models are vital tools for optimizing the recanalization therapy. Here we report a murine thrombotic stroke model based on transient cerebral hypoxic-ischemic (tHI) insult, which triggers thrombosis and infarction, and responds favorably to tissue plasminogen activator (tPA)-mediated fibrinolysis in a therapeutic window similar to those in stroke patients. https://www.jove.com/v/52978 361 2015-08-18T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58217.jpg Minimally Invasive Endoscopic Intracerebral Hemorrhage Evacuation This paper details the surgical protocol for minimally invasive endoscopic intracerebral hemorrhage evacuation using the SCUBA technique. https://www.jove.com/v/58217 541 2021-10-15T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63309.jpg Intracranial Pressure Monitoring In Nontraumatic Intraventricular Hemorrhage Rodent Model Monitoring intracranial pressure in rodent models of nontraumatic intraventricular hemorrhage is not common in the current literature. Herein, we demonstrate a technique for measuring intracranial pressure, mean arterial pressure, and cerebral perfusion pressure during intraventricular hemorrhage in a rat animal model. https://www.jove.com/v/63309 498 2022-02-08T22:45:00+00:00 JoVE no https://visualize.jove.com/31783392-active-inference-as-a-unifying-generic-and-adaptive-framework-for-a-p300-based-bci monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17738.jpg Cognitivism Cognitive psychology emerged as a significant field in the mid-20th century. It focused on understanding humans' internal mental processes. This approach emphasizes how people perceive, remember, think, and solve problems—elements critical to human cognition. Previously dominated by behaviorism, which prioritized observable behaviors and largely ignored mental processes, psychology transformed in the 1950s. Cognitive psychologists argue that understanding how we think and process information is... https://www.jove.com/v/17738 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18143.jpg Introduction to Cognitive Psychology Cognitive psychology is the field of psychology dedicated to examining how people think. It attempts to explain how and why we think the way we do by studying the interactions among human thinking, emotion, creativity, language, and problem-solving, as well as other cognitive processes. Cognitive psychology studies how information is processed and manipulated in remembering, thinking, and knowing. This field emerged in the mid-20th century, following a period dominated by behaviorism, which... https://www.jove.com/v/18143 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18562.jpg Information Processing Approach The information-processing theory of cognitive development centers on fundamental mental processes, including attention, memory, and problem-solving skills. Researchers in this field examine how cognitive abilities, such as working memory, evolve and influence children's overall development. Studies indicate that children with stronger working memory tend to excel in reading comprehension, math, and problem-solving compared to peers with less efficient memory skills. Low working memory is also... https://www.jove.com/v/18562 90 JoVE no https://cloudfront.jove.com/files/ftp_upload/19923/19923_article_thumb_19923.jpg Automatic Processing and Automatic Social Behavior Automatic processing refers to the cognitive operations that occur without conscious intent or awareness, playing a fundamental role in shaping social cognition and behavior. These processes enable individuals to navigate complex social environments efficiently by relying on mental shortcuts and pre-existing knowledge structures known as schemas. One of the most influential mechanisms underlying automatic processing is priming, which subtly activates mental representations through exposure to... https://www.jove.com/v/19923 88 2025-09-18T17:24:15+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53639.jpg Assessment and Communication for People with Disorders of Consciousness With this experiment, one might be able to detect consciousness in people with disorders of consciousness. Furthermore, the approach can create a simple communication channel that enables people to give simple YES/NO answers to... https://www.jove.com/v/53639 457 9500 2017-08-01T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61943.jpg Real-Time Proxy-Control of Re-Parameterized Peripheral Signals using a Close-Loop Interface We present protocols and methods of analyses to build co-adaptive interfaces that stream, parameterize, analyze, and modify human body and heart signals in close-loop. This setup interfaces signals derived from the peripheral and central nervous systems of the person with external sensory inputs to help track biophysical change. https://www.jove.com/v/61943 714 5000 2021-05-08T14:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64959.jpg P300-Based Brain-Computer Interface Speller Performance Estimation with Classifier-Based Latency Estimation This article presents a method for estimating same-day P300 speller Brain-Computer Interface (BCI) accuracy using a small testing dataset. https://www.jove.com/v/64959 369 861 2023-09-08T12:00:00+00:00 JoVE no https://visualize.jove.com/31791963-finding-the-best-fit-examining-the-decision-making-of-augmentative-and-alternative-communication-professionals-in-the-uk-using-a-discrete-choice-experiment monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11026.jpg Factorial Design Factorial Analysis is an experimental design that applies Analysis of Variance (ANOVA) statistical procedures to examine a change in a dependent variable due to more than one independent variable, also known as factors. Changes in worker productivity can be reasoned, for example, to be influenced by salary and other conditions, such as skill level. One way to test this hypothesis is by categorizing salary into three levels (low, moderate, and high) and skills sets into two levels (entry level... https://www.jove.com/v/11026 121 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13613.jpg Decision Making: P -value Method The process of hypothesis testing based on the P-value method includes calculating the P- value using the sample data and interpreting it. First, a specific claim about the population parameter is proposed. The claim is based on the research question and is stated in a simple form. Further, an opposing statement to the claim is also stated. These statements can act as null and alternative hypotheses: a null hypothesis would be a neutral statement while the alternative hypothesis can have a... https://www.jove.com/v/13613 69 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13614.jpg Decision Making: Traditional Method The process of hypothesis testing based on the traditional method includes calculating the critical value, testing the value of the test statistic using the sample data, and interpreting these values. First, a specific claim about the population parameter is decided based on the research question and is stated in a simple form. Further, an opposing statement to this claim is also stated. These statements can act as null and alternative hypotheses, out of which a null hypothesis would be a... https://www.jove.com/v/13614 74 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52286.jpg Practical Methodology of Cognitive Tasks Within a Navigational Assessment Children who have complex communication needs can benefit from the use of a speech-generating device (SGD). Cognitive skills were identified as having an impact on the ability to navigate between levels of SGDs. This protocol describes the steps needed for Speech-language Pathologists to assess cognitive skills and navigational abilities. https://www.jove.com/v/52286 319 2015-06-01T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61267.jpg Involving Individuals with Developmental Language Disorder and Their Parents/Carers in Research Priority Setting A protocol to enable individuals with developmental language disorder (DLD) and their parents/carers to meaningfully participate in a research priority setting exercise is established. The protocol includes a defined program of activities for data collection, and methods to incorporate this data into the broader research priority setting process. https://www.jove.com/v/61267 376 2020-06-06T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67500.jpg Online Repetitive Transcranial Magnetic Stimulation of Dorsomedial and Dorsolateral Prefrontal Cortex in Cognition Decision Making, and Cognitive Dissonance This protocol presents a more precise and effective method of repetitive transcranial magnetic stimulation of the dorsolateral and dorsomedial prefrontal cortices during an experimental task using neuronavigation and robotic systems. Based on the results, crucial implications are suggested for future online stimulation research. https://www.jove.com/v/67500 800 2025-12-05T12:30:00+00:00 JoVE no https://visualize.jove.com/31822855-correction-to-artificial-intelligence-for-diabetic-retinopathy-screening-a-review monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40911/40911_article_thumb_40911.jpg Diabetic Retinopathy DefinitionDiabetic retinopathy is a microvascular complication of diabetes affecting the retinal blood vessels.Risk FactorsDiabetic retinopathy is present in almost all individuals with type 1 diabetes and more than 60% of those with type 2 diabetes after two decades of disease.The risk increases with poor glycemic control, hypertension, dyslipidemia, smoking, pregnancy, and puberty.Although cataracts and glaucoma are also more frequent in people with diabetes, retinopathy remains the leading... https://www.jove.com/v/40911 87 2026-04-13T14:37:50+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61806.jpg Behavioral Assessment of Visual Function via Optomotor Response and Cognitive Function via Y-Maze in Diabetic Rats Neural degeneration in both eyes and brain as a result of diabetes can be observed through behavioral tests carried out on rodents. The Y-maze, a measure of spatial cognition, and the optomotor response, a measure of visual function, both provide insight into potential diagnoses and... https://www.jove.com/v/61806 461 6600 2020-10-23T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66123.jpg Author Spotlight: Understanding Retinal Vessel Resilience and Disease Progression A protection assay was developed to monitor the retinal vasculature's resilience to death from diabetes/diabetic retinopathy-related insults such as oxidative stress and cytokines. https://www.jove.com/v/66123 276 1500 2024-01-12T14:05:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66687.jpg Tear-Derived Exosomal miR-15a as New Diagnostic Tool for Diabetic Retinopathy This article describes a protocol for the collection and detection of miR-15a from tears as a new diagnostic tool for diabetic... https://www.jove.com/v/66687 465 35 2025-12-30T12:30:00+00:00 JoVE no https://visualize.jove.com/32022674-artificial-intelligence-in-sleep-medicine-an-american-academy-of-sleep-medicine-position-statement monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14943.jpg Sleep-Wake Cycles Sleep is an essential physiological process vital to maintaining overall well-being. The reticular activating system (RAS), a network of neurons in the brainstem, regulates wakefulness and sleep. While it may seem passive, sleep consists of distinct cycles, each with its unique characteristics and functions. Two key sleep phases are non-rapid eye movement (NREM) and rapid eye movement (REM). NREM Sleep NREM sleep comprises four progressive stages that seamlessly merge: Stage 1 is the... https://www.jove.com/v/14943 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17788.jpg Understanding Sleep Sleep, an essential biological state, involves significant reductions in physical activity, sensory awareness, and interaction with the environment. This complex physiological process is primarily regulated by specific brain regions, notably the hypothalamus and pons, which govern the sleep-wake cycle or circadian rhythm. The circadian rhythm, a nearly 24-hour cycle, is deeply influenced by environmental light cues. Light exposure directly affects the hypothalamus, which in turn regulates... https://www.jove.com/v/17788 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17794.jpg Sleepwalking and Sleep Talking Somnambulism, commonly known as sleepwalking, involves individuals engaging in activities ranging from simple walking to more complex behaviors such as driving. Sleepwalking typically occurs during the slow-wave sleep stages 3 and 4 early in the night when the person is not dreaming, contradicting the myth that sleepwalkers are acting out their dreams. Factors that increase the likelihood of sleepwalking include sleep deprivation and alcohol consumption. Contrary to common beliefs, it is safe... https://www.jove.com/v/17794 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17795.jpg REM Sleep Behavior Disorder REM Sleep Behavior Disorder (RBD) is a sleep disorder characterized by the absence of muscle paralysis that normally occurs during the REM phase of sleep. This absence allows individuals to physically act out their dreams, which are often vivid and disturbing. Common behaviors exhibited during episodes include kicking, punching, and yelling. These actions can be dangerous, potentially leading to injuries for the person with RBD or their bed partner. RBD is significantly associated with... https://www.jove.com/v/17795 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17797.jpg Sleep Apnea Sleep apnea is a condition where breathing stops intermittently during sleep, often leading to significant health issues. Each episode can last from 10 to 20 seconds or more and is frequently accompanied by a brief arousal from sleep. This disturbance, largely unnoticed by the individual, can lead to severe daytime fatigue. Commonly, individuals seek help after being informed by their partners about loud snoring and noticeable breathing pauses during sleep. The condition is more prevalent among... https://www.jove.com/v/17797 81 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17798.jpg Narcolepsy Narcolepsy is a chronic sleep disorder characterized by pervasive, uncontrolled sleepiness and other sleep disturbances. One of its hallmark symptoms is an abrupt transition to REM sleep upon falling asleep, which causes symptoms typically associated with this phase to occur unexpectedly during wakefulness. These include the following symptoms, which typically last from a minute or two to half an hour. • Sleep Paralysis and Cataplexy: Similar to paralysis during REM sleep that prevents acting... https://www.jove.com/v/17798 67 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54739.jpg Drug-Induced Sleep Endoscopy (DISE) with Target Controlled Infusion (TCI) and Bispectral Analysis in Obstructive Sleep Apnea The aim of this study was to establish a standardized protocol for sleep endoscopy to differentiate obstruction patterns in obstructive sleep apnea (OSA). Target-controlled infusion (TCI) of the sedative was combined with real-time monitoring of the depth of sedation using bispectral analysis. https://www.jove.com/v/54739 474 2016-12-06T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58823.jpg Multi-Modal Home Sleep Monitoring in Older Adults Here, we present a protocol to improve the quality of data from home sleep testing by providing a method to enhance instructions through a structured participant visit. This protocol includes the implementation of a step-by-step educational manual with photos to ensure proper placement of equipment. https://www.jove.com/v/58823 460 2019-01-26T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66950.jpg IntelliSleepScorer, a Software Package with a Graphic User Interface for Mice Automated Sleep Stage Scoring We present a software package with a graphic user interface for researchers without coding experience to score sleep stages in mice with a simple download and operation. https://www.jove.com/v/66950 294 2024-11-08T21:20:00+00:00 JoVE no https://visualize.jove.com/32324146-age-related-differences-in-the-evaluation-of-a-virtual-health-agents-appearance-and-embodiment-in-a-health-related-interaction-experimental-lab-study monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2379.jpg Brain Imaging Investigation of the Neural Correlates of Observing Virtual Social Interactions This article demonstrates an experimental design in which whole-body animated characters are used in conjunction with functional magnetic resonance imaging (fMRI) to investigate the neural correlates of observing virtual social... https://www.jove.com/v/2379 645 12000 2011-07-06T12:00:00+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19895/19895_article_thumb_19895.jpg Impression Management Techniques I: Managing Appearances Appearance is a multidimensional aspect of self-presentation that encompasses observable attributes such as clothing, grooming, speech, and nonverbal behavior. These elements are often strategically managed to align with socially constructed expectations in different settings. For instance, individuals tailor their appearance during job interviews, social gatherings, or athletic events to meet the perceived norms of those environments.Contextual Adaptation and Social SignalsThe research... https://www.jove.com/v/19895 89 2025-09-18T10:24:15+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54784.jpg Creating Virtual-hand and Virtual-face Illusions to Investigate Self-representation Here, we describe virtual-hand and virtual-face illusion paradigms that can be used to study body-related self-perception/-representation. They have already been used in various studies to demonstrate that, under specific conditions, a virtual hand or face can be incorporated into one's body representation, suggesting that body representations are rather... https://www.jove.com/v/54784 413 13700 2017-03-01T10:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58318.jpg Virtual Reality Experiments with Physiological Measures Virtual reality (VR) experiments can be difficult to implement and require meticulous planning. This protocol describes a method for the design and implementation of VR experiments that collect physiological data from human participants. The Experiments in Virtual Environments (EVE) framework is employed to accelerate this... https://www.jove.com/v/58318 429 13100 2018-08-29T15:00:00+00:00 JoVE no https://visualize.jove.com/32376611-diagnostic-accuracy-of-diabetic-retinopathy-grading-by-an-artificial-intelligence-enabled-algorithm-compared-with-a-human-standard-for-wide-field-true-colour-confocal-scanning-and-standard-digital-retinal-images monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40911/40911_article_thumb_40911.jpg Diabetic Retinopathy DefinitionDiabetic retinopathy is a microvascular complication of diabetes affecting the retinal blood vessels.Risk FactorsDiabetic retinopathy is present in almost all individuals with type 1 diabetes and more than 60% of those with type 2 diabetes after two decades of disease.The risk increases with poor glycemic control, hypertension, dyslipidemia, smoking, pregnancy, and puberty.Although cataracts and glaucoma are also more frequent in people with diabetes, retinopathy remains the leading... https://www.jove.com/v/40911 87 2026-04-13T21:37:50+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56137.jpg Using Retinal Imaging to Study Dementia The retina shares prominent similarities with the brain and thus represents a unique window to study vasculature and neuronal structure in the brain non-invasively. This protocol describes a method to study dementia using retinal imaging techniques. This method can potentially aid in diagnosis and risk assessment of... https://www.jove.com/v/56137 557 22100 2017-11-06T17:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68083.jpg Detection and Isolation of Cancer in Prostate Biopsies Using Stimulated Raman Histology and Artificial Intelligence Here, we present a standardized protocol for detecting prostate cancer using stimulated Raman histology (SRH) on biopsy samples due to advantages over traditional histopathology, focusing on sample preparation, imaging, and artificial intelligence to improve the cancer-to-tissue ratio. Additionally, it supports biobanking for transcriptomics, organoid or xenograft models, and identification of intraoperative surgical... https://www.jove.com/v/68083 485 1000 2025-06-10T12:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68270.jpg Introduction of an Integrated Pathology Image Management, Artificial Intelligence, and Reporting System Integrated image management, artificial intelligence (AI), and reporting systems have revolutionized diagnostic pathology practice. In this paper, we introduce FlexLIS, a state-of-the-art system that enables AI to assist pathologists in performing histopathology image assessments and generating diagnostic reports. https://www.jove.com/v/68270 333 673 2025-07-11T15:40:00+00:00 JoVE no https://visualize.jove.com/32477083-remote-automated-and-mri-compatible-administration-of-interoceptive-inspiratory-resistive-loading monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16399.jpg Mechanical Ventilation II: Invasive Ventilation Ventilators are essential medical equipment used to aid patients with respiratory difficulties. Their primary function is to assist or replace spontaneous breathing by providing mechanical ventilation. There are two general classes of mechanical ventilators: negative-pressure and positive-pressure ventilators. Negative-Pressure Ventilators Negative-pressure ventilators create a vacuum around the chest or body to draw air into the lungs, simulating breathing. This method does not require an... https://www.jove.com/v/16399 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52306.jpg MRI Mapping of Cerebrovascular Reactivity via Gas Inhalation Challenges Non-invasive imaging of the brain vasculature’s ability to dilate or constrict may allow a better understanding of cerebrovascular pathophysiology in various neurological diseases. The present report describes a reproducible and patient-comfortable protocol to perform vascular reactivity imaging in humans using magnetic resonance imaging... https://www.jove.com/v/52306 573 14500 2014-12-17T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59420.jpg Functional MRI in Conjunction with a Novel MRI-compatible Hand-induced Robotic Device to Evaluate Rehabilitation of Individuals Recovering from Hand Grip Deficits We performed functional MRI using a novel MRI-compatible hand-induced robotic device to evaluate its utility for monitoring hand motor function in individuals recovering from neurological... https://www.jove.com/v/59420 454 8200 2019-11-23T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66386.jpg Author Spotlight: A Novel Standardized Technique for Real-Time Biomedical Imaging of Acute Myocardial Injury This article presents a unique closed-chest technique for inducing myocardial ischemia-reperfusion injury (IRI) in mice. The presented method allows mice to breathe spontaneously while remotely inducing myocardial ischemia. This provides access to the animal for studying the dynamic processes of ischemia and reperfusion in situ and in real-time via noninvasive... https://www.jove.com/v/66386 437 1500 2024-03-22T13:40:00+00:00 JoVE no https://visualize.jove.com/32530174-application-of-artificial-intelligence-automatic-diatom-identification-system-in-practical-cases monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40816/40816_article_thumb_40816.jpg Automated Microbial Diagnostics Automated diagnostic analyzers have transformed clinical microbiology by providing rapid and reliable methods for pathogen identification and antibiotic susceptibility testing. Among these systems, the Vitek 2 is widely used because it automates the traditionally labor-intensive processes of microbial identification (ID) and antibiotic susceptibility testing (AST), delivering standardized and timely results that are essential for effective patient care.Microbial Identification with ID CardsThe... https://www.jove.com/v/40816 84 2026-03-12T20:35:56+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64320.jpg Automatic Image Processing to Determine the Community Size Structure of Riverine Macroinvertebrates The article is based on the creation of an adapted protocol to scan, detect, sort, and identify digitized objects corresponding to benthic river macroinvertebrates using a semi-automatic imaging procedure. This procedure allows the acquisition of the individual size distributions and size metrics of a macroinvertebrate community in about 1... https://www.jove.com/v/64320 536 2800 2023-01-13T12:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65557.jpg Author Spotlight: AI-Driven Trypanosome Species Detection from Microscopic Images Worldwide medical blood parasites were automatically screened using simple steps on a low-code AI platform. The prospective diagnosis of blood films was improved by using an object detection and classification method in a hybrid deep learning model. The collaboration of active monitoring and well-trained models helps to identify hotspots of trypanosome... https://www.jove.com/v/65557 500 2300 2023-10-27T13:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65792.jpg Author Spotlight: Diatom Testing for Forensic Drowning Examination This article describes a protocol for diatom DNA extraction using a modified common DNA extraction... https://www.jove.com/v/65792 260 2700 2023-11-10T13:10:00+00:00 JoVE no https://visualize.jove.com/32643058-keeping-the-human-in-the-loop-in-the-age-of-artificial-intelligence-accompanying-commentary-for-correcting-the-brain-by-rainey-and-erden monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11043.jpg Reason and Intuition The human brain processes information for decision-making using one of two routes: an intuitive system and a rational system (Epstein, 1994; popularized by Kahneman, 2011 as System 1 and System 2, respectively). The intuitive system is quick, impulsive, and operates with minimal effort, relying on emotions or habits to provide cues for what to do next, while the rational system is logical, analytical, deliberate, and methodical. Research in neuropsychology suggests that the brain can only use... https://www.jove.com/v/11043 97 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11048.jpg The Anchoring-and-Adjustment Heuristic In order to make good decisions, we use our knowledge and our reasoning. Often, this knowledge and reasoning is sound and solid. However, sometimes, we are swayed by biases or by others manipulating a situation. For example, let’s say you and three friends wanted to rent a house and had a combined target budget of $1,600. The realtor shows you only very run-down houses for $1,600 and then shows you a very nice house for $2,000. Might you ask each person to pay more in rent to get the $2,000... https://www.jove.com/v/11048 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12157.jpg Non-equilibrium in the Cell An important concept in studying metabolism and energy is that of chemical equilibrium. Most chemical reactions are reversible. They can proceed in both directions, releasing energy into their environment in one direction, and absorbing it from the environment in the other direction. The same is true for the chemical reactions involved in cell metabolism, such as the breaking down and building up of proteins into and from individual amino acids, respectively. Reactants within a closed system... https://www.jove.com/v/12157 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16031.jpg Control Systems Control systems are everywhere in contemporary society, influencing diverse applications from aerospace to automated manufacturing. These systems can be found naturally within biological processes, such as blood sugar regulation and heart rate adjustment in response to stress, as well as in man-made systems like elevators and automated vehicles. A control system is essentially a network of subsystems and processes that collaboratively convert specific inputs into desired outputs. At the heart... https://www.jove.com/v/16031 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17746.jpg Organization of the Brain The brain is an integral component of the nervous system and serves as the center for processing sensory inputs, making decisions, and directing bodily actions. This complex organ is organized into three primary sections: the hindbrain, midbrain, and forebrain, each responsible for a range of vital functions. Hindbrain The hindbrain, located at the base of the brain, plays a vital role in regulating automatic processes that sustain life. It includes the medulla oblongata, which is essential for... https://www.jove.com/v/17746 91 2026-06-29T12:11:34+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18143.jpg Introduction to Cognitive Psychology Cognitive psychology is the field of psychology dedicated to examining how people think. It attempts to explain how and why we think the way we do by studying the interactions among human thinking, emotion, creativity, language, and problem-solving, as well as other cognitive processes. Cognitive psychology studies how information is processed and manipulated in remembering, thinking, and knowing. This field emerged in the mid-20th century, following a period dominated by behaviorism, which... https://www.jove.com/v/18143 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61943.jpg Real-Time Proxy-Control of Re-Parameterized Peripheral Signals using a Close-Loop Interface We present protocols and methods of analyses to build co-adaptive interfaces that stream, parameterize, analyze, and modify human body and heart signals in close-loop. This setup interfaces signals derived from the peripheral and central nervous systems of the person with external sensory inputs to help track biophysical change. https://www.jove.com/v/61943 714 2021-05-08T14:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68824.jpg High-definition Transcranial Direct Current Stimulation over Right Dorsolateral Prefrontal Cortex to Enhance Metacognitive Sensitivity This study proposed an experimental paradigm that applies High-Definition Transcranial Direct Current Stimulation (HD-tDCS) to improve human metacognition in human-AI delegation tasks. The results demonstrated the effectiveness of HD-tDCS in enhancing metacognitive sensitivity. https://www.jove.com/v/68824 371 2025-09-26T13:40:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/69621.jpg Estimate the Cognitive Load Using Electrocardiographic Measure: A Human-AI Collaborative Task This protocol describes the use of physiological indicators to measure variations in cognitive load across different task difficulty levels in human-AI collaborative tasks. The findings suggest that people adapt their decision-making processes according to task difficulty, thereby reflecting different levels of cognitive load. https://www.jove.com/v/69621 428 2025-12-05T14:45:00+00:00 JoVE no https://visualize.jove.com/33067882-angiotensin-converting-enzyme-open-for-business-structural-insights-into-the-subdomain-dynamics monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11516.jpg Ligand Binding and Linkage Allosteric proteins have more than one ligand binding site; the binding of a ligand to any of these sites influences the binding of ligands to the other sites. When a protein is allosteric, its binding sites are called coupled or linked. In the case of enzymes, the site that binds to the substrate is known as the active site and the other site is known as the regulatory site. When a ligand binds to the regulatory site, this leads to conformational changes in the protein that can influence the... https://www.jove.com/v/11516 49 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11904.jpg ATP Synthase: Structure ATP synthase or ATPase is among the most conserved proteins found in bacteria, mammals, and plants. This enzyme can catalyze a forward reaction in response to the electrochemical gradient, producing ATP from ADP and inorganic phosphate. ATP synthase can also work in a reverse direction by hydrolyzing ATP and generating an electrochemical gradient. Different forms of ATP synthases have evolved special features to meet the specific demands of the cell. Based on their specific feature, ATP... https://www.jove.com/v/11904 78 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12221.jpg Allosteric Proteins-ATCase Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor. Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,... https://www.jove.com/v/12221 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14426.jpg Transducer Mechanism: Enzyme-Linked Receptors Enzyme-linked receptors are cell-surface receptors acting as an enzyme or associating with an enzyme intracellularly. They make excellent drug targets. Drugs can bind to the extracellular ligand-binding domain or directly affect their enzymatic domain and alter their activity. Major types that are helpful drug targets include: Receptor tyrosine kinases: Receptor tyrosine kinases (RTKs) phosphorylate specific tyrosines on the signaling proteins. RTKs include various growth factor receptors,... https://www.jove.com/v/14426 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15023.jpg Antihypertensive Drugs: Angiotensin-Converting Enzyme Inhibitors Angiotensin-converting enzyme (ACE), a vital component of the renin-angiotensin-aldosterone system, is abundant in lung endothelial cells. ACE converts the inactive decapeptide, angiotensin I, into the active octapeptide, angiotensin II. This potent vasoconstrictor narrows blood vessels, increasing resistance to blood flow and elevating blood pressure. Angiotensin II also stimulates aldosterone production, encouraging kidney cells to reabsorb more sodium and water from urine, thereby increasing... https://www.jove.com/v/15023 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15024.jpg Antihypertensive Drugs: Angiotensin II Receptor Blockers In the renin-angiotensin-aldosterone system, a hormone called angiotensin II plays a crucial role. It binds to the AT1 receptors in vascular smooth muscles coupled with Gq proteins. The activation of these receptors activates an enzyme called phospholipase C, which releases two molecules: inositol trisphosphate and diacylglycerol. These molecules cause a chain reaction that leads to the phosphorylation of myosin light chains and promotes interaction between actin and myosin, leading to smooth... https://www.jove.com/v/15024 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55177.jpg Live Cell Imaging and 3D Analysis of Angiotensin Receptor Type 1a Trafficking in Transfected Human Embryonic Kidney Cells Using Confocal Microscopy Here we present a protocol to image cells expressing green fluorescent protein-tagged angiotensin type 1a receptors during endocytosis initiated by angiotensin II treatment. This technique includes labeling lysosomes with a second fluorescent marker, and then utilizing software to analyze the co-localization of receptor and lysosome in three dimensions over time. https://www.jove.com/v/55177 591 2017-03-27T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55640.jpg Investigating Protein Sequence-structure-dynamics Relationships with Bio3D-web A protocol for the online investigation of protein sequence-structure-dynamics relationships using Bio3D-web is presented. https://www.jove.com/v/55640 591 2017-07-16T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62770.jpg Chemical Modification of the Tryptophan Residue in a Recombinant Ca 2+ -ATPase N-domain for Studying Tryptophan-ANS FRET ANS binds to the Ca2+-ATPase recombinant N-domain. Fluorescence spectra display a FRET-like pattern upon excitation at a wavelength of 295 nm. NBS-mediated chemical modification of Trp quenches the fluorescence of the N-domain, which leads to the absence of energy transfer (FRET) between the Trp residue and ANS. https://www.jove.com/v/62770 727 2021-10-09T13:00:00+00:00 JoVE no https://visualize.jove.com/33109646-awareness-of-cognitive-abilities-in-the-execution-of-activities-of-daily-living-after-acquired-brain-injury-an-evaluation-protocol monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18559.jpg Cognitive Development During Adulthood Cognitive development continues throughout adulthood, undergoing significant shifts across early, middle, and late stages. Individual transition occurs from adolescent idealism to pragmatic and adaptable thinking in early adulthood. During this period, individuals learn to integrate personal beliefs with the recognition that other perspectives are equally valid. Exposure to the complexities of modern society, diverse experiences, and higher education contribute to this adaptive thought process,... https://www.jove.com/v/18559 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53639.jpg Assessment and Communication for People with Disorders of Consciousness With this experiment, one might be able to detect consciousness in people with disorders of consciousness. Furthermore, the approach can create a simple communication channel that enables people to give simple YES/NO answers to... https://www.jove.com/v/53639 457 9500 2017-08-01T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63991.jpg Dual-Task Stroop Paradigm for Detecting Cognitive Deficits in High-Functioning Stroke Patients Clinical assessment scales are notsensitive enough to cognitive dysfunction in high-functioning stroke patients. The dual-task paradigm presents advantages and potential in the assessment and cognitive training of cognitive dysfunction. The study here proposes a dual-task Stroop paradigm to identify cognitive dysfunction in high-functioning stroke patients. https://www.jove.com/v/63991 462 3400 2022-12-16T12:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67809.jpg Randomized, Triple-Blind, and Parallel-Controlled Trial of Transcranial Direct Current Stimulation for Cognitive Rehabilitation after Stroke This study presents a novel transcranial direct current stimulation (tDCS) protocol combined with cognitive stimulation to address post-stroke hemispatial neglect. Initial data from a pilot patient ensure the procedure's feasibility and suggest potential efficacy, providing a foundation for a future parallel, triple-blind, controlled clinical... https://www.jove.com/v/67809 533 1200 2025-06-06T13:10:00+00:00 JoVE no https://visualize.jove.com/33118580-quantifying-patterns-in-optical-micrographs-of-one-and-two-dimensional-ellipsoidal-particle-assemblies monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13405.jpg Electron Microscope Tomography and Single-particle Reconstruction Transmission electron microscopy (TEM) can be used to determine the 3D structure of biological samples with the help of techniques such as electron microscope tomography and single-particle reconstruction. While single-particle reconstruction can examine macromolecules and macromolecular complexes in vitro conditions only, tomography permits the study of cell components or small cells in vivo. Electron Tomography Electron tomography can be performed either in TEM or STEM (scanning transmission... https://www.jove.com/v/13405 67 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60894.jpg Assembly and Characterization of Polyelectrolyte Complex Micelles We provide protocols and representative data for designing, assembling, and characterizing polyelectrolyte complex micelles, core-shell nanoparticles formed by polyelectrolytes and hydrophilic charged-uncharged block... https://www.jove.com/v/60894 524 11300 2020-03-02T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61636.jpg Three-Dimensional Particle Shape Analysis Using X-ray Computed Tomography: Experimental Procedure and Analysis Algorithms for Metal Powders The size and shape of powder particles are not independent quantities. Usual measurement techniques do not measure these intertwined parameters in three dimensions (3D). A 3D measurement/analysis technique is described, based on X-ray computed tomography, which can measure size and shape and classify powder particles according to both... https://www.jove.com/v/61636 610 2000 2020-12-04T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63131.jpg Patterning of Microorganisms and Microparticles through Sequential Capillarity-assisted Assembly We present a technology that uses capillarity-assisted assembly in a microfluidic platform to pattern micro-sized objects suspended in a liquid, such as bacteria and colloids, into prescribed arrays on a polydimethylsiloxane... https://www.jove.com/v/63131 617 3600 2021-11-04T13:00:00+00:00 JoVE no https://visualize.jove.com/33389412-in-vitro-ibuprofen-release-monitoring-using-carbon-quantum-dots monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4236.jpg Compact Quantum Dots for Single-molecule Imaging We describe the preparation of colloidal quantum dots with minimized hydrodynamic size for single-molecule fluorescence imaging. Compared to conventional quantum dots, these nanoparticles are similar in size to globular proteins and are optimized for single-molecule brightness, stability against photodegradation, and resistance to nonspecific binding to proteins and... https://www.jove.com/v/4236 1034 18400 2012-10-09T12:00:00+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17160/17160_article_thumb_17160.jpg In Vitro Drug Release Testing: Overview, Development and Validation In vitro dissolution and drug release tests assess how quickly and how much of a drug is released from its dosage form into an aqueous medium under standardized laboratory conditions. These tests are essential tools in pharmaceutical development and quality assurance, offering insight into the drug's performance before clinical use.During formulation development, dissolution testing identifies incomplete or inconsistent drug release issues. It also supports decisions on selecting the optimal... https://www.jove.com/v/17160 70 2025-10-03T14:00:23+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53261.jpg A Rapid and Quantitative Fluorimetric Method for Protein-Targeting Small Molecule Drug Screening A protocol for small molecular drug screening based on in-situ synthesis of ultrasmall fluorescent gold nanoclusters (Au NCs) using drug-loaded protein as template is presented. This method is simple to determine the binding affinity of drugs to a target protein by a visible fluorescent signal emitted from the protein-templated Au... https://www.jove.com/v/53261 514 10300 2015-10-16T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67000.jpg Author Spotlight: High-Quality Quantum Dot Nanobeads for Sensitive Fluorescent Lateral Flow Immunoassays Here, we describe a protocol for the preparation of quantum dot nanobeads (QDNB) and the detection of disease biomarkers using QDNB-based lateral flow immunoassay strips. The test results can be qualitatively assessed under UV light illumination and quantitatively measured using a fluorescent strip reader within 15... https://www.jove.com/v/67000 433 1800 2024-06-28T14:40:00+00:00 JoVE no https://visualize.jove.com/33906732-induction-motor-control-system-with-a-programmable-logic-controller-plc-and-profibus-communication-for-industrial-plants-an-experimental-setup monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16031.jpg Control Systems Control systems are everywhere in contemporary society, influencing diverse applications from aerospace to automated manufacturing. These systems can be found naturally within biological processes, such as blood sugar regulation and heart rate adjustment in response to stress, as well as in man-made systems like elevators and automated vehicles. A control system is essentially a network of subsystems and processes that collaboratively convert specific inputs into desired outputs. At the heart... https://www.jove.com/v/16031 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16032.jpg Control Systems: Applications Electrical engineering plays a pivotal role in our daily lives, with control systems at the heart of many applications, from home appliances to sophisticated space shuttles. Control systems manage and regulate the behavior of devices and processes, ensuring they function safely, correctly, and efficiently. In modern vehicles, control systems manage various functions to enhance performance and safety. The steering wheel and accelerator are primary inputs in a car's control system. The direction... https://www.jove.com/v/16032 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16092.jpg Open and closed-loop control systems Control systems are foundational elements in automation and engineering. They are broadly categorized into open-loop and closed-loop systems. These classifications hinge on the presence or absence of feedback mechanisms, significantly influencing the system's performance, complexity, and application. An open-loop control system operates without feedback from the output. It consists of two primary elements: the controller and the controlled process. The controller receives an input signal and... https://www.jove.com/v/16092 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16125.jpg Controller Configurations Controller configurations are crucial in a car's cruise control system because they manage speed over time to maintain a consistent pace regardless of road conditions, thereby meeting design goals. In traditional control systems, fixed-configuration design involves predetermined controller placement. System performance modifications are known as compensation. Control-system compensation involves various configurations, most commonly series or cascade compensation, in which the controller aligns... https://www.jove.com/v/16125 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16129.jpg PI Controller: Design Proportional Integral (PI) controllers are a fundamental component in modern control systems, widely used to enhance performance and mitigate steady-state errors. They are particularly effective in applications such as automatic brightness adjustment on smartphones, where they excel at mitigating steady-state errors for step-function inputs. Unlike PD controllers, which require time-varying errors to function optimally, PI controllers leverage their integral component to address residual... https://www.jove.com/v/16129 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16131.jpg PID Controller Proportional-Integral-Derivative (PID) controllers are widely used in various control systems to enhance stability and performance. In a thermostat, it adjusts heating or cooling based on the temperature difference between the actual and desired levels. They are often used in automotive speed systems, effectively managing sudden speed changes while maintaining a constant speed under varying conditions. On the other hand, PI controllers, commonly employed in voltage regulation, enhance stability... https://www.jove.com/v/16131 79 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56422.jpg The Modular Design and Production of an Intelligent Robot Based on a Closed-Loop Control Strategy We present a protocol on modular design and production of intelligent robots to help scientific and technical workers design intelligent robots with special production tasks based on personal needs and individualized design. https://www.jove.com/v/56422 713 2017-10-14T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63342.jpg Interactive and Visualized Online Experimentation System for Engineering Education and Research This work describes an online experimentation system that provides visualized experiments, including the visualization of theories, concepts, and formulas, visualizing the experimental process with three-dimensional (3-D) virtual test rigs, and visualizing the control and monitoring system using widgets such as charts and cameras. https://www.jove.com/v/63342 515 2021-11-24T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63717.jpg Data Communication Based on MQTT in a Polymer Extrusion Process This work proposes a flexible method for data communication between a film extrusion system and monitoring devices based on a message protocol called Message Queuing Telemetry Transport (MQTT). https://www.jove.com/v/63717 495 2022-07-15T20:00:00+00:00 JoVE no https://visualize.jove.com/33966817-challenges-of-radiology-education-in-the-era-of-artificial-intelligence monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12958.jpg Current Trends in Nursing II Trends in nursing are multifactorial and associated with changes in society, within the nursing profession, and in other professions. Notably, telehealth and remote nursing contribute to successful healthcare delivery for numerous patients and help reduce stress for nurses due to nursing shortages. Nurses can reach patients, monitor their conditions, and interact with them using computers, audio, visual accessories, and telephones—for example, remote patient monitoring systems. Likewise,... https://www.jove.com/v/12958 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12979.jpg Issues And Trends In Healthcare Delivery System The issues and trends in healthcare delivery are constantly changing. The COVID-19 pandemic is one recent issue that wreaked havoc on healthcare systems, causing a shortage of healthcare workers, high demand for medicines and supplies, and increased medical expenditure due to a lack of insurance. Other issues include rising healthcare costs and care fragmentation. Cost Containment Payment for healthcare services has historically promoted adoption of costly and often unnecessary or inefficient... https://www.jove.com/v/12979 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16374.jpg Radiological Investigation I: X-ray and CT Radiological investigations, including X-rays and computed tomography (CT) scans, are critical for diagnosing and evaluating various medical conditions. These imaging techniques provide valuable insights into the body's internal structures, aiding in the detection of abnormalities, assessment of disease progression, and development of treatment strategies. This article delves into two primary radiological investigations, chest X-rays and CT scans, outlining their purpose, procedures, and the... https://www.jove.com/v/16374 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64051.jpg Bridging the Technology Divide in the COVID-19 Era: Using Virtual Outreach to Expose Middle and High School Students to Imaging Technology This article presents an overview of how synchronous web-based virtual outreach can be used to expose 6th-12th grade students to advanced imaging technologies such as ultrasound, computerized tomography, and electroencephalography. The paper discusses the methods and equipment needed to livestream integrated educational sessions for effective student engagement in... https://www.jove.com/v/64051 595 1800 2022-09-28T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66014.jpg Author Spotlight: Advancing CBCT and Digital Dental Image Integration with AI-Assisted Digitization A process of registering cone-beam computed tomography scans and digital dental images has been presented using artificial intelligence (AI) -assisted identification of landmarks and merging. A comparison with surface-based registration shows that AI-based digitization and integration are reliable and... https://www.jove.com/v/66014 349 1100 2024-02-23T13:35:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68270.jpg Introduction of an Integrated Pathology Image Management, Artificial Intelligence, and Reporting System Integrated image management, artificial intelligence (AI), and reporting systems have revolutionized diagnostic pathology practice. In this paper, we introduce FlexLIS, a state-of-the-art system that enables AI to assist pathologists in performing histopathology image assessments and generating diagnostic reports. https://www.jove.com/v/68270 333 487 2025-07-11T15:40:00+00:00 JoVE no https://visualize.jove.com/34071990-analysis-and-comparison-of-two-artificial-intelligence-diabetic-retinopathy-screening-algorithms-in-a-pilot-study-idx-dr-and-retinalyze monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40911/40911_article_thumb_40911.jpg Diabetic Retinopathy DefinitionDiabetic retinopathy is a microvascular complication of diabetes affecting the retinal blood vessels.Risk FactorsDiabetic retinopathy is present in almost all individuals with type 1 diabetes and more than 60% of those with type 2 diabetes after two decades of disease.The risk increases with poor glycemic control, hypertension, dyslipidemia, smoking, pregnancy, and puberty.Although cataracts and glaucoma are also more frequent in people with diabetes, retinopathy remains the leading... https://www.jove.com/v/40911 87 2026-04-13T21:37:50+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61806.jpg Behavioral Assessment of Visual Function via Optomotor Response and Cognitive Function via Y-Maze in Diabetic Rats Neural degeneration in both eyes and brain as a result of diabetes can be observed through behavioral tests carried out on rodents. The Y-maze, a measure of spatial cognition, and the optomotor response, a measure of visual function, both provide insight into potential diagnoses and... https://www.jove.com/v/61806 461 6200 2020-10-23T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63782.jpg In Vivo Vascular Injury Readouts in Mouse Retina to Promote Reproducibility Here, we present three data analysis protocols for fluorescein angiography (FA) and optical coherence tomography (OCT) images in the study of Retinal Vein Occlusion... https://www.jove.com/v/63782 455 2400 2022-04-21T13:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66123.jpg Author Spotlight: Understanding Retinal Vessel Resilience and Disease Progression A protection assay was developed to monitor the retinal vasculature's resilience to death from diabetes/diabetic retinopathy-related insults such as oxidative stress and cytokines. https://www.jove.com/v/66123 276 1300 2024-01-12T14:05:00+00:00 JoVE no https://visualize.jove.com/34291297-automation-for-life-science-laboratories monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40816/40816_article_thumb_40816.jpg Automated Microbial Diagnostics Automated diagnostic analyzers have transformed clinical microbiology by providing rapid and reliable methods for pathogen identification and antibiotic susceptibility testing. Among these systems, the Vitek 2 is widely used because it automates the traditionally labor-intensive processes of microbial identification (ID) and antibiotic susceptibility testing (AST), delivering standardized and timely results that are essential for effective patient care.Microbial Identification with ID CardsThe... https://www.jove.com/v/40816 84 2026-03-12T20:35:56+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53485.jpg A Semi-automated Approach to Preparing Antibody Cocktails for Immunophenotypic Analysis of Human Peripheral Blood Whole blood Immunophenotyping is indispensable for monitoring the human immune system. However, the number of reagents required and the instability of specific fluorochromes in premixed cocktails necessitates daily reagent preparation. Here we show that semi-automated preparation of staining antibody cocktail helps establish reliable immunophenotyping by minimizing variability in reagent... https://www.jove.com/v/53485 497 10900 2016-02-08T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54703.jpg Automated Robotic Liquid Handling Assembly of Modular DNA Devices Here, an automated workflow to perform modular DNA "device" assembly using a modular cloning DNA assembly method on liquid-handling robots is presented. The protocol uses an intuitive software tool for generating liquid handler picklists for combinatorial DNA device library generation, which we demonstrate using two liquid handling... https://www.jove.com/v/54703 682 12600 2017-12-01T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68448.jpg Efficient Sampling of Genetically Encoded Biosensor Design Space Enabled with a Design of Experiments and Automation Workflow This protocol provides a method for the systematic global optimization of genetically encoded biosensors through automation-assisted genetic library generation and assessment. This is coupled with design-of-experiment methodologies to streamline experimentation and enable the selection of genetic components to tune biosensors to specific design outcomes. https://www.jove.com/v/68448 545 99 2025-10-17T12:50:00+00:00 JoVE no https://visualize.jove.com/34297039-adar-and-hnrnpc-deficiency-synergize-in-activating-endogenous-dsrna-induced-type-i-ifn-responses monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10804.jpg RNA Interference RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated. This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used... https://www.jove.com/v/10804 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11993.jpg Exon Recombination The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes. Exon shuffling follows “splice frame rules.” Each exon has three reading... https://www.jove.com/v/11993 152 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12033.jpg Experimental RNAi RNA interference (RNAi) is a cellular mechanism that inhibits gene expression by suppressing its transcription or activating the RNA degradation process. The mechanism was discovered by Andrew Fire and Craig Mello in 1998 in plants. Today, it is observed in almost all eukaryotes, including protozoa, flies, nematodes, insects, parasites, and mammals. This precise cellular mechanism of gene silencing has been developed into a technique that provides an efficient way to identify and determine the... https://www.jove.com/v/12033 135 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14427.jpg Transducer Mechanism: Nuclear Receptors Nuclear receptors, or NRs, are unique transcription factors that regulate gene transcription and affect the cellular pathways involved in reproduction, development, or metabolism. Their ability to be stimulated by small lipophilic ligands and control vital cellular processes makes them ideal drug targets. Nearly 10-15% of currently prescribed drugs target these receptors. About 48 different soluble family members of nuclear receptors are identified that can be divided into two main classes: <br... https://www.jove.com/v/14427 91 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15355.jpg Immune Response Against Viral Pathogens The immune system's response to viral infections is a complex and coordinated process involving natural killer (NK) cells, T cell-mediated responses, and antibody-mediated responses. NK Cells NK cells are a crucial part of our innate immune system, acting as the first line of defense against viral infections. These cells can recognize and kill infected cells without prior exposure to the virus, effectively slowing down the spread of infection. Additionally, NK cells produce proinflammatory... https://www.jove.com/v/15355 89 JoVE no https://cloudfront.jove.com/files/ftp_upload/40862/40862_article_thumb_40862.jpg Inhibitors of Viral Protein Synthesis Protein synthesis is indispensable for viral replication, as viruses lack the cellular machinery required for this process and must hijack the host's translational apparatus. In response, host cells deploy a critical innate immune defense involving interferons, specialized cytokines that play a central role in inhibiting viral propagation.Upon viral detection, infected cells release interferons that bind to receptors on adjacent uninfected cells, activating the JAK-STAT signaling pathway and... https://www.jove.com/v/40862 90 2026-03-12T13:36:03+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51415.jpg Monitoring Activation of the Antiviral Pattern Recognition Receptors RIG-I And PKR By Limited Protease Digestion and Native PAGE Innate defenses to virus infections are triggered by pattern recognition receptors (PRRs). The two cytoplasmic PRRs RIG-I and PKR bind to viral signature RNAs, change conformation, oligomerize, and activate antiviral signaling. Methods are described which allow to conveniently monitor the conformational switching and the oligomerization of these cytoplasmic PRRs. https://www.jove.com/v/51415 763 2014-07-29T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52650.jpg High-throughput Quantitative Real-time RT-PCR Assay for Determining Expression Profiles of Types I and III Interferon Subtypes This protocol describes a high-throughput qRT-PCR assay for the analysis of type I and III IFN expression signatures. The assay discriminates single base pair differences between the highly similar transcripts of these genes. Through batch assembly and robotic pipetting, the assays are consistent and reproducible. https://www.jove.com/v/52650 600 2015-03-24T16:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59095.jpg Confocal Imaging of Double-Stranded RNA and Pattern Recognition Receptors in Negative-Sense RNA Virus Infection Double-stranded RNA produced during RNA virus replication can be recognized by pattern recognition receptors to induce an innate immune response. For negative-sense RNA viruses, the interaction between the low-level dsRNA and PRRs remains unclear. We have developed a confocal microscopy method to visualize arenavirus dsRNA and PRR in individual cells. https://www.jove.com/v/59095 404 2019-01-26T15:00:00+00:00 JoVE no https://visualize.jove.com/34331748-implementation-of-the-australian-computer-assisted-theragnostics-auscat-network-for-radiation-oncology-data-extraction-reporting-and-distributed-learning monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2414.jpg Generation of Comprehensive Thoracic Oncology Database - Tool for Translational Research A thoracic oncology database was developed to serve as a comprehensive repository for clinical and laboratory data for the purposes of translational research. The database will serve translational cancer researchers within the Thoracic Oncology Research Program. This database is adaptable to other cancer models, as well as other human... https://www.jove.com/v/2414 678 16200 2011-01-22T17:15:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17623.jpg Cancer Survival Analysis Cancer survival analysis focuses on quantifying and interpreting the time from a key starting point, such as diagnosis or the initiation of treatment, to a specific endpoint, such as remission or death. This analysis provides critical insights into treatment effectiveness and factors that influence patient outcomes, helping to shape clinical decisions and guide prognostic evaluations. A cornerstone of oncology research, survival analysis tackles the challenges of skewed, non-normally... https://www.jove.com/v/17623 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57411.jpg Radiation Planning Assistant - A Streamlined, Fully Automated Radiotherapy Treatment Planning System Radiation therapy is a highly complex cancer treatment that requires multiple specialists to create a treatment plan and provide quality assurance (QA) prior to delivery to a patient. This protocol describes the use of a fully automated system, the Radiation Planning Assistant (RPA), to create high-quality radiation treatment... https://www.jove.com/v/57411 505 15500 2018-04-11T14:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65504.jpg Author Spotlight: Improving Radiation Therapy Access with Radiation Planning Assistant This protocol describes a series of automated tools designed for high-quality radiotherapy autocontouring and autoplanning that are being packaged into a web-based service to maximize robustness and scalability while minimizing operational... https://www.jove.com/v/65504 318 1600 2023-10-06T13:30:00+00:00 JoVE no https://visualize.jove.com/34379525-comparison-of-an-automated-plate-assessment-system-apas-independence-and-artificial-intelligence-ai-to-manual-plate-reading-of-methicillin-resistant-and-methicillin-susceptible-staphylococcus-aureus-chromagar-surveillance-cultures monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40816/40816_article_thumb_40816.jpg Automated Microbial Diagnostics Automated diagnostic analyzers have transformed clinical microbiology by providing rapid and reliable methods for pathogen identification and antibiotic susceptibility testing. Among these systems, the Vitek 2 is widely used because it automates the traditionally labor-intensive processes of microbial identification (ID) and antibiotic susceptibility testing (AST), delivering standardized and timely results that are essential for effective patient care.Microbial Identification with ID CardsThe... https://www.jove.com/v/40816 84 2026-03-12T20:35:56+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50474.jpg Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria Lytic phage biosensors and antibody beads are able to discriminate between methicillin resistant (MRSA) and sensitive staphylococcus bacteria. The phages were immobilized by a Langmuir-Blodgett method onto a surface of a quartz crystal microbalance sensor and worked as broad range staphylococcus probes. Antibody beads recognize... https://www.jove.com/v/50474 844 24700 2013-05-08T09:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64785.jpg Application of the Intelligent High-Throughput Antimicrobial Sensitivity Testing/Phage Screening System and Lar Index of Antimicrobial Resistance Here we introduce the principle, structure, and instruction of the intelligent high-throughput antimicrobial sensitivity testing/phage screening system. Its application is illustrated by using Salmonella isolated from poultry in Shandong, China, as an example. The Lar index is calculated, and its significance in evaluating antimicrobial resistance is discussed... https://www.jove.com/v/64785 599 1500 2023-07-21T14:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66588.jpg Author Spotlight: Accelerating Diagnostic Accuracy with Direct Identification of Gram-Negatives from Blood Culture Bottles EUCAST has developed a direct antimicrobial susceptibility testing (AST) protocol for automated blood cultures. However, its dependence on mass spectrometry-based microbial identification can be obviated by using a direct inoculum preparation protocol in an automated microbial identification system. This approach can provide AST reports within 24 h of sample... https://www.jove.com/v/66588 547 1100 2024-05-24T13:40:00+00:00 JoVE no https://visualize.jove.com/34428513-the-diagnosis-of-amnestic-mild-cognitive-impairment-by-combining-the-characteristics-of-brain-functional-network-and-support-vector-machine-classifier monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40948/40948_article_thumb_40948.jpg Dementia l: Introduction Dementia is an acquired, progressive syndrome characterized by a decline in multiple cognitive domains severe enough to impair daily functioning and reduce independence. Although memory loss is a central feature, the diagnosis requires additional deficits involving language, executive function, visuospatial skills, judgment, calculation, or abstract reasoning. These cognitive impairments reflect underlying neurodegenerative or vascular processes that gradually disrupt neuronal networks... https://www.jove.com/v/40948 82 2026-04-13T23:55:59+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50319.jpg Identification of Disease-related Spatial Covariance Patterns using Neuroimaging Data Multivariate techniques including principal component analysis (PCA) have been used to identify signature patterns of regional change in functional brain images. We have developed an algorithm to identify reproducible network biomarkers for the diagnosis of neurodegenerative disorders, assessment of disease progression, and objective evaluation of treatment effects in patient... https://www.jove.com/v/50319 867 15900 2013-06-26T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56015.jpg Application of Granger Causality Analysis of the Directed Functional Connection in Alzheimer's Disease and Mild Cognitive Impairment Based on resting-state functional magnetic resonance imaging with Granger causality analysis, we investigated the alterations in the directed functional connectivity between the posterior cingulate cortex and whole brain in patients with Alzheimer's Disease (AD), patients with Mild Cognitive Impairment (MCI), and healthy... https://www.jove.com/v/56015 523 8100 2017-08-07T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59653.jpg Brain Infarct Segmentation and Registration on MRI or CT for Lesion-symptom Mapping Provided here is a practical tutorial for an open-access, standardized image processing pipeline for the purpose of lesion-symptom mapping. A step-by-step walkthrough is provided for each processing step, from manual infarct segmentation on CT/MRI to subsequent registration to standard space, along with practical recommendations and illustrations with exemplary... https://www.jove.com/v/59653 625 48600 2019-09-25T13:00:00+00:00 JoVE no https://visualize.jove.com/34441174-external-stimuli-on-neural-networks-analytical-and-numerical-approaches monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14900.jpg Neural Circuits Neural circuits and neuronal pools are two of the main structures found in the nervous system. Neural circuits are networks of neurons that work together to carry out a specific task or process. They consist of interconnected neurons and glial cells, which provide structural and metabolic support. Neuronal pools are collections of nerve cells with similar functions and interact through chemical and electrical signals. These pools include both interneurons (the central neural circuit nodes that... https://www.jove.com/v/14900 85 2025-06-13T16:07:11+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17743.jpg Neuronal Communication Neurons, the fundamental units of the brain and nervous system, communicate through complex electrochemical signals that underpin all cognitive and bodily functions. This communication is primarily facilitated by a process involving the generation and propagation of an action potential along the axon of the neuron. When the internal electrical charge of a neuron surpasses a certain threshold, an action potential is triggered. This rapid change in voltage travels swiftly along the axon to the... https://www.jove.com/v/17743 88 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52341.jpg Closed-loop Neuro-robotic Experiments to Test Computational Properties of Neuronal Networks In this paper, an experimental framework to perform closed-loop experiments is presented, in which information processing (i.e., coding and decoding) and learning of neuronal assemblies are studied during the continuous interaction with a robotic... https://www.jove.com/v/52341 678 10500 2015-03-02T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53576.jpg Induction of an Isoelectric Brain State to Investigate the Impact of Endogenous Synaptic Activity on Neuronal Excitability In Vivo This procedure performs long-lasting in vivo intracellular recordings from single neurons during physiologically relevant cerebral states and after complete abolition of ongoing electrical activities, resulting in an isoelectric brain state. The physiological constants of the animal are carefully monitored during the transition to the artificial comatose... https://www.jove.com/v/53576 619 8300 2016-03-31T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55726.jpg Time-dependent Increase in the Network Response to the Stimulation of Neuronal Cell Cultures on Micro-electrode Arrays Mouse neuronal cells cultured on multi-electrode arrays display an increase in response following electrical stimulation. This protocol demonstrates how to culture neurons, how to record activity, and how to establish a protocol to train the networks to respond to patterns of... https://www.jove.com/v/55726 645 10100 2017-05-29T15:00:00+00:00 JoVE no https://visualize.jove.com/34593056-bacterial-mutagenicity-test-data-collection-by-the-task-force-of-the-japan-pharmaceutical-manufacturers-association monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10813.jpg In-vitro Mutagenesis To learn more about the function of a gene, researchers can observe what happens when the gene is inactivated or “knocked out,” by creating genetically engineered knockout animals. Knockout mice have been particularly useful as models for human diseases such as cancer, Parkinson’s disease, and diabetes. The Process Genes can be randomly knocked out, or specific genes can be targeted. To knock out a particular gene, an engineered piece of DNA called a targeting vector is used to replace the... https://www.jove.com/v/10813 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10813.jpg In vitro Mutagenesis To learn more about the function of a gene, researchers can observe what happens when the gene is inactivated or “knocked out,” by creating genetically engineered knockout animals. Knockout mice have been particularly useful as models for human diseases such as cancer, Parkinson’s disease, and diabetes. The Process Genes can be randomly knocked out, or specific genes can be targeted. To knock out a particular gene, an engineered piece of DNA called a targeting vector is used to replace the... https://www.jove.com/v/12024 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14392.jpg Mutagenicity and Carcinogenicity Mutagenicity and carcinogenicity refer to the ability of drugs to cause genetic defects and induce cancer, respectively. The International Agency for Research on Cancer (IARC) classifies agents into four groups based on their carcinogenic potential. Group 1 agents are known human carcinogens; group 2A agents are probably carcinogenic to humans; group 3 agents lack data to support their role in carcinogenesis; and group 4 includes agents for which data support that they are not likely to be... https://www.jove.com/v/14392 85 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54119.jpg A Protocol for Functional Assessment of Whole-Protein Saturation Mutagenesis Libraries Utilizing High-Throughput Sequencing We present a protocol for the functional assessment of comprehensive single-site saturation mutagenesis libraries of proteins utilizing high-throughput sequencing. Importantly, this approach uses orthogonal primer pairs to multiplex library construction and sequencing. Representative results using TEM-1 β-lactamase selected at a clinically relevant dosage of ampicillin are provided. https://www.jove.com/v/54119 696 2016-07-03T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57510.jpg The Lambda Select cII Mutation Detection System We describe a detailed protocol for the Lambda Select cII mutation assay in cultured cells of transgenic rodents or the corresponding animals treated with a chemical/physical agent of interest. This approach has been widely used for mutagenicity testing of carcinogens in mammalian cells. https://www.jove.com/v/57510 428 2018-04-26T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60406.jpg Measuring Microbial Mutation Rates with the Fluctuation Assay Here, a protocol is presented to perform a fluctuation assay and estimate microbial mutation rate using phenotypic markers. This protocol will enable researchers to assay mutations in diverse microbes and environments, determining how genotype and ecological context affect spontaneous mutation rates. https://www.jove.com/v/60406 464 2019-11-28T21:00:00+00:00 JoVE no https://visualize.jove.com/34663938-organoids-in-image-based-phenotypic-chemical-screens monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12025.jpg Genetic Screens Genetic screens are tools used to identify genes and mutations responsible for phenotypes of interest. Genetic screens help identify individuals or a group of people at risk of developing genetic diseases and help them with early intervention, targeted therapy, and reproductive options. Forward genetic screens Forward or “classical” genetic screens involve creating random mutations in an organism’s DNA using radiation, mutagens, or insertion of additional bases, which result in visible changes... https://www.jove.com/v/12025 166 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62269.jpg Toxicity Screens in Human Retinal Organoids for Pharmaceutical Discovery Here we present a step-by-step protocol to generate mature human retinal organoids and utilize them in a photoreceptor toxicity assay to identify pharmaceutical candidates for the age-related retinal degenerative disease macular telangiectasia type 2... https://www.jove.com/v/62269 465 3500 2021-03-04T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64405.jpg A High-Throughput Platform for Culture and 3D Imaging of Organoids This paper presents a fabrication protocol for a new type of culture substrate with hundreds of microcontainers per mm2, in which organoids can be cultured and observed using high-resolution microscopy. The cell seeding and immunostaining protocols are also... https://www.jove.com/v/64405 462 3400 2022-10-14T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64434.jpg Multiparametric Tumor Organoid Drug Screening Using Widefield Live-Cell Imaging for Bulk and Single-Organoid Analysis This protocol describes a semi-automated method for medium- to high-throughput organoid drug screenings and microscope-agnostic, automated image analysis software to quantify and visualize multiparametric, single-organoid drug responses to capture intratumor heterogeneity. https://www.jove.com/v/64434 761 5200 2022-12-23T13:50:00+00:00 JoVE no https://visualize.jove.com/34670459-artificial-intelligence-in-toxicological-pathology-quantitative-evaluation-of-compound-induced-follicular-cell-hypertrophy-in-rat-thyroid-gland-using-deep-learning-models monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17273/17273_article_thumb_17273.jpg Toxicity Testing in Animals Toxicity tests in animals are grounded on two main assumptions: first, the effects observed in laboratory animals can be extrapolated to humans, especially when adjusted for body surface area; second, high-dose exposure in animals is essential to identify potential human hazards from lower doses. This is based on the quantal dose-response concept, which faces the challenge of extrapolating results from relatively few test animals to much larger human populations. For example, a 0.01% incidence... https://www.jove.com/v/17273 83 2026-02-12T19:17:01+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40889/40889_article_thumb_40889.jpg Hyperthyroidism II: Pathophysiology Hyperthyroidism is a hypermetabolic state caused by elevated levels of thyroid hormones, triiodothyronine (T3) and thyroxine (T4). It results from dysregulation at the thyroid, pituitary, or immune system level and affects multiple organ systems.PathophysiologyThe most common cause of hyperthyroidism is Graves’ disease, an autoimmune disorder in which antibodies, specifically thyroid-stimulating antibodies (TSAb), a subtype of TSH receptor antibodies (TRAb), bind to and activate TSH receptors... https://www.jove.com/v/40889 87 2026-05-14T19:31:58+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64480.jpg A Swin Transformer-Based Model for Thyroid Nodule Detection in Ultrasound Images Here, a new model for thyroid nodule detection in ultrasound images is proposed, which uses Swin Transformer as the backbone to perform long-range context modeling. Experiments prove that it performs well in terms of sensitivity and... https://www.jove.com/v/64480 263 2000 2023-04-21T14:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65657.jpg Author Spotlight: In Vivo Assessment of Thyroid Hormone Disruption Using the THAI Mouse Model The Thyroid Hormone Action Indicator mouse model was developed to enable tissue-specific quantification of local thyroid hormone action using its endogenous regulatory machinery. Recently, it has been shown that the model is suitable for characterizing endocrine-disrupting chemicals interacting with thyroid hormone economy, both by ex vivo and in vivo... https://www.jove.com/v/65657 254 1000 2023-10-06T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66569.jpg Author Spotlight: Integrating Ultrasound Imaging with Biochemical Markers for Thyroid Disease Diagnosis Here we present a 5D ultrasound technique combining multi-planar 3D reconstruction and color Doppler fusion, which enables synchronous visualization of thyroid structural and functional information. By minimizing blind spots, this method allows rapid, precise localization of lesions to improve diagnostic accuracy, especially benefiting novice... https://www.jove.com/v/66569 341 781 2024-02-09T15:00:00+00:00 JoVE no https://visualize.jove.com/34729843-attentional-sampling-of-visual-and-auditory-objects-is-captured-by-theta-modulated-neural-activity monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4262.jpg Mapping Cortical Dynamics Using Simultaneous MEG/EEG and Anatomically-constrained Minimum-norm Estimates: an Auditory Attention Example We use magneto- and electroencephalography (MEG/EEG), combined with anatomical information captured by magnetic resonance imaging (MRI), to map the dynamics of the cortical network associated with auditory... https://www.jove.com/v/4262 525 14800 2012-10-24T13:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14942.jpg Brain Waves Brain waves are electrical signals generated by the neurons in the brain, which are regularly monitored to measure mental activities. Brain waves and their frequency ranges can be measured using an electroencephalogram or EEG. There are four main types of brain waves, each with distinct characteristics: • Alpha Waves – Alpha brain waves, between 8 and 13 Hz ( Hertz), occur when a person is relaxed with eyes closed. The alpha waves then disappear when one is concentrating on specific tasks. <br... https://www.jove.com/v/14942 83 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55089.jpg Automatic Detection of Highly Organized Theta Oscillations in the Murine EEG Theta activity in the hippocampus is related to specific cognitive and behavioral stages. Here, we describe an analytical method to detect highly-organized theta oscillations within the hippocampus using a time-frequency (i.e., wavelet analysis)-based... https://www.jove.com/v/55089 575 9300 2017-03-10T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57349.jpg Optogenetic Entrainment of Hippocampal Theta Oscillations in Behaving Mice We describe the use of optogenetics and electrophysiological recordings for selective manipulations of hippocampal theta oscillations (5-10 Hz) in behaving mice. The efficacy of the rhythm entrainment is monitored using local field potential. A combination of opto- and pharmacogenetic inhibition addresses the efferent readout of hippocampal... https://www.jove.com/v/57349 453 11900 2018-06-29T13:30:00+00:00 JoVE no https://visualize.jove.com/34729977-dual-channel-imaging-of-amyloid-β-plaques-and-peroxynitrite-to-illuminate-their-correlations-in-alzheimers-disease-using-a-unimolecular-two-photon-fluorescent-probe monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40941/40941_article_thumb_40941.jpg Alzheimer Disease ll: Pathophysiology Alzheimer disease involves structural changes in the brain that begin long before symptoms appear. The most distinctive features are extracellular neuritic plaques and intracellular neurofibrillary tangles.Neuritic plaques form in the cerebral cortex and around blood vessels. These plaques contain a dense core of beta-amyloid (Aβ)—a toxic protein fragment that clumps outside neurons. The core is surrounded by damaged neuronal extensions, as well as reactive astrocytes and microglia. Abnormal... https://www.jove.com/v/40941 83 2026-04-13T06:37:54+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54060.jpg Correlative Light and Electron Microscopy to Study Microglial Interactions with β-Amyloid Plaques This article describes a protocol for visualizing amyloid Aβ plaques in Alzheimer's disease mouse models using methoxy-X04, which crosses the blood-brain barrier and selectively binds to β-pleated sheets found in dense core Aβ plaques. It allows pre-screening of plaque-containing tissue sections prior to immunostaining and processing for electron... https://www.jove.com/v/54060 652 11600 2016-06-01T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56279.jpg Imaging Amyloid Tissues Stained with Luminescent Conjugated Oligothiophenes by Hyperspectral Confocal Microscopy and Fluorescence Lifetime Imaging Amyloid deposition is a hallmark of different diseases and afflicts many different organs. This paper describes the application of luminescent conjugated oligothiophene fluorescence staining in combination with fluorescence microscopy techniques. This staining method represents a powerful tool for detection and exploration of protein aggregates in both clinical and scientific... https://www.jove.com/v/56279 604 13600 2017-10-20T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65670.jpg Author Spotlight: Non-Invasive Imaging of Complex Bio-Structures Using Polarization-Sensitive Two-Photon Microscopy This paper describes how polarization-sensitive two-photon microscopy could be applied to characterize the local organization within label-free amyloid superstructures-spherulites. It also describes how to prepare and measure the sample, assemble the required setup, and analyze the data to obtain information about the local organization of amyloid... https://www.jove.com/v/65670 354 1400 2023-09-08T12:20:00+00:00 JoVE no https://visualize.jove.com/34792695-aso-author-reflections-applications-of-artificial-intelligence-in-oesophago-gastric-malignancies-present-work-and-future-directions monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12091.jpg Targeted Cancer Therapies The targeted cancer therapies, also known as “molecular targeted therapies,” take advantage of the molecular and genetic differences between the cancer cells and the normal cells. It needs a thorough understanding of the cancer cells to develop drugs that can target specific molecular aspects that drive the growth, progression, and spread of cancer cells without affecting the growth and survival of other normal cells in the body. There are several types of targeted therapies against specific... https://www.jove.com/v/12091 177 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16415.jpg Gastroesophageal Reflux Disease II: Clinical Features and Management Gastroesophageal reflux disease, or GERD, is a persistent medical condition that affects many individuals worldwide. Its clinical manifestations can vary greatly, making diagnosis and management challenging for healthcare professionals. The following is a comprehensive overview of the clinical manifestations, assessment, and management strategies for GERD. Clinical Manifestations GERD presents itself in a multitude of ways, with symptoms varying from person to person. The hallmark symptoms are... https://www.jove.com/v/16415 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16419.jpg Barrett Esophagus-II: Clinical Manifestations and Management Individuals with Barrett's esophagus are often asymptomatic, but they may experience symptoms commonly associated with GERD, such as heartburn and acid regurgitation. Additional symptoms can include difficulty swallowing, chest pain, unintentional weight loss, blood in the stool (which may appear black, tarry, or bloody), and episodes of vomiting. To diagnose Barrett's esophagus, healthcare providers often recommend an endoscopy for those showing symptoms of acid reflux. The procedure entails... https://www.jove.com/v/16419 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53170.jpg Intraoperative Gastroscopy for Tumor Localization in Laparoscopic Surgery for Gastric Adenocarcinoma In early gastric cancer, the aim of surgery is to precisely remove the distal stomach including the primary tumor. To do this, accurate localization of the tumor is crucial, especially in totally laparoscopic surgery. This protocol describes a procedure for intraoperative gastroscopy in totally laparoscopic subtotal gastrectomy. https://www.jove.com/v/53170 631 2016-08-09T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66155.jpg Techniques of Endoscopic Ossiculoplasty Exclusive Endoscopic ossiculoplasty (EEO) is a promising and minimally invasive approach for the treatment of conductive hearing loss due to ossicular chain disruptions and associated middle ear pathologies. Herein, step-by-step instructions and a discussion of various endoscopic ossiculoplasty techniques are presented. https://www.jove.com/v/66155 547 2024-01-26T22:40:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67522.jpg Mixed Reality Assisted Radical Endoscopic Thyroidectomy Radical endoscopic thyroidectomy is associated with various surgical complications. This study utilizes mixed reality techniques to assist surgeons in performing radical endoscopic thyroidectomy, aiming to enhance its safety and lower the surgical threshold. https://www.jove.com/v/67522 486 2025-01-31T21:40:00+00:00 JoVE no https://visualize.jove.com/34792842-the-impact-of-learning-curve-experience-on-transcatheter-aortic-valve-replacement-outcomes-insights-from-the-united-kingdom-and-ireland-all-comers-second-generation-acurate-neo-transcatheter-aortic-heart-valve-registry monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17904/17904_article_thumb_17904.jpg Aortic Regurgitation II: Clinical Features and Diagnostic Tests Aortic valve regurgitation (AR) occurs when the aortic valve fails to close properly, allowing blood to flow backward from the aorta into the left ventricle. This backflow can result in two distinct clinical presentations: acute and chronic AR, each characterized by its own set of symptoms and physical findings.Acute Aortic RegurgitationAcute AR presents with a sudden onset of severe symptoms. Patients typically experience profound dyspnea (shortness of breath), chest pain, and signs of left... https://www.jove.com/v/17904 82 2025-06-19T14:46:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57858.jpg Improved Registration of 3D CT Angiography with X-ray Fluoroscopy for Image Fusion During Transcatheter Aortic Valve Implantation The aim of this study was to improve the co-registration for image fusion (IF) of pre-interventional CT data with real-time x-ray (XR) fluoroscopy during transfemoral transcatheter aortic valve implantation... https://www.jove.com/v/57858 419 10700 2018-06-03T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63367.jpg Four-Dimensional Computed Tomography-Guided Valve Sizing for Transcatheter Pulmonary Valve Replacement This study assessed a new methodology with a straightened model generated from the four-dimensional cardiac computed tomography sequence to obtain the desired measurements for valve sizing in the application of transcatheter pulmonary valve... https://www.jove.com/v/63367 597 2800 2022-01-20T14:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68470.jpg Upper-extremity Approach for Secondary Access in Transfemoral Transcatheter Aortic Valve Implantation An upper-extremity approach for secondary access during transfemoral transcatheter aortic valve implantation is associated with fewer secondary access site-related bleeding complications and reduces time to mobilization in patients requiring extended pacing. This protocol aims to provide an extensive overview of the upper-extremity approach and guide operators in adopting this methodology. https://www.jove.com/v/68470 364 237 2025-08-08T13:10:00+00:00 JoVE no https://visualize.jove.com/34808896-architecture-agnostic-algorithm-for-reconfigurable-optical-interferometer-programming monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11296.jpg Interference and Diffraction Interference is a characteristic phenomenon exhibited by waves. When two electromagnetic waves interact with their peaks and troughs coinciding, a resulting wave with enhanced amplitude is produced. This is known as constructive interference. In this case, the two waves interacting are in phase with each other. Alternatively, if the two waves coincide and interact in a way such that the trough of one wave coincides with the peak of the other (in an out of phase manner), the resultant wave will... https://www.jove.com/v/11296 138 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50021.jpg Bringing the Visible Universe into Focus with Robo-AO Light from astronomical objects must travel through the earth's turbulent atmosphere before it can be imaged by ground-based telescopes. To enable direct imaging at maximum theoretical angular resolution, advanced techniques such as those employed by the Robo-AO adaptive-optics system must be... https://www.jove.com/v/50021 635 19700 2013-02-12T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50564.jpg The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry Large laser-interferometers are being constructed to create a new type of astronomy based on gravitational waves. Their sensitivities, as for many other high-precision experiments, are approaching fundamental noise limits such as the atomic vibration of their components. We are pioneering technologies to overcome these limits using novel laser beam... https://www.jove.com/v/50564 734 22000 2013-08-12T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60269.jpg Characterization of SiN Integrated Optical Phased Arrays on a Wafer-Scale Test Station Here, we describe the operation of a SiN integrated photonic circuit containing optical phased arrays. The circuits are used to emit low divergence laser beams in the near infrared and steer them in two... https://www.jove.com/v/60269 357 8200 2020-04-01T13:00:00+00:00 JoVE no https://visualize.jove.com/34980281-diabetic-retinopathy-classification-for-supervised-machine-learning-algorithms monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40911/40911_article_thumb_40911.jpg Diabetic Retinopathy DefinitionDiabetic retinopathy is a microvascular complication of diabetes affecting the retinal blood vessels.Risk FactorsDiabetic retinopathy is present in almost all individuals with type 1 diabetes and more than 60% of those with type 2 diabetes after two decades of disease.The risk increases with poor glycemic control, hypertension, dyslipidemia, smoking, pregnancy, and puberty.Although cataracts and glaucoma are also more frequent in people with diabetes, retinopathy remains the leading... https://www.jove.com/v/40911 87 2026-04-13T21:37:50+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56137.jpg Using Retinal Imaging to Study Dementia The retina shares prominent similarities with the brain and thus represents a unique window to study vasculature and neuronal structure in the brain non-invasively. This protocol describes a method to study dementia using retinal imaging techniques. This method can potentially aid in diagnosis and risk assessment of... https://www.jove.com/v/56137 557 21800 2017-11-06T17:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58382.jpg Predicting Treatment Response to Image-Guided Therapies Using Machine Learning: An Example for Trans-Arterial Treatment of Hepatocellular Carcinoma Intra-arterial therapies are the standard of care for patients with hepatocellular carcinoma who cannot undergo surgical resection. A method for predicting response to these therapies is proposed. The technique uses pre-procedural clinical, demographic, and imaging information to train machine learning models capable of predicting response prior to... https://www.jove.com/v/58382 249 8400 2018-10-10T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66123.jpg Author Spotlight: Understanding Retinal Vessel Resilience and Disease Progression A protection assay was developed to monitor the retinal vasculature's resilience to death from diabetes/diabetic retinopathy-related insults such as oxidative stress and cytokines. https://www.jove.com/v/66123 276 1200 2024-01-12T14:05:00+00:00 JoVE no https://visualize.jove.com/34982148-transitions-in-development-an-interview-with-alberto-roselló-díez monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10995.jpg Sustainable Development As the human population continues to grow and use resources, we must be mindful of our planet’s natural limits. Sustainable development provides a pathway to maintain and improve human life now while also ensuring that future generations will have the resources that they need. The long-term success of sustainability efforts rests on understanding the interplay between human actions and ecological systems. The oceans are one important focus of global conservation efforts. Overfishing,... https://www.jove.com/v/10995 103 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11023.jpg Longitudinal Research Sometimes we want to see how people change over time, as in studies of human development and lifespan. When we test the same group of individuals repeatedly over an extended period of time, we are conducting longitudinal research. Longitudinal research is a research design in which data-gathering is administered repeatedly over an extended period of time. For example, we may survey a group of individuals about their dietary habits at age 20, retest them a decade later at age 30, and then again... https://www.jove.com/v/11023 140 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18550.jpg Introduction to Developmental Psychology Developmental psychology explores the changes and continuities in human abilities throughout life, encompassing physical, cognitive, linguistic, and social dimensions. Human development is not restricted to growth, but includes aspects of decline, particularly in physical abilities as individuals age. Developmental psychologists seek to understand how people change as they age and how their mental and social skills evolve.Developmental MilestonesA key concept in developmental psychology is... https://www.jove.com/v/18550 87 2025-08-13T20:50:24+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18551.jpg Three Developmental Domains Human development is typically examined across three main domains: physical, cognitive, and socio-emotional. These domains represent the significant areas of change and continuity throughout the lifespan, from infancy to late adulthood. Physical Development Physical processes, also known as maturation, encompass the biological changes that occur across an individual's life. These changes begin with genetic inheritance and continue through various stages, including growth in height and weight,... https://www.jove.com/v/18551 89 2025-08-13T20:50:23+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18573.jpg Erikson's Theory on Socioemotional Development during Adulthood Erik Erikson's theory of psychosocial development outlines a series of stages through which individuals progress across the lifespan. Each stage involves a psychosocial conflict that significantly influences personal growth and well-being. Three key stages — intimacy versus isolation, generativity versus stagnation, and integrity versus despair — highlight the developmental challenges faced in adulthood. Intimacy Versus Isolation in Early Adulthood Individuals in early adulthood, from the 20s... https://www.jove.com/v/18573 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18576.jpg Socioemotional Experience and Gender Development Social-emotional experiences and cultural influences play significant roles in shaping gender development. During middle childhood, from ages 6 to 11, peer groups become dominant in reinforcing gender norms. Children in this age group often align with same-gender peer groups, which actively encourage behaviors that conform to traditional gender roles. For instance, boys may be discouraged from engaging in activities perceived as feminine, reinforcing culturally dictated norms about masculinity... https://www.jove.com/v/18576 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60282.jpg Imaging and Analysis of Tissue Orientation and Growth Dynamics in the Developing Drosophila Epithelia During Pupal Stages This protocol is designed for the imaging and analysis of the dynamics of cell orientation and tissue growth in the Drosophila abdominal epithelia as the fruit fly undergoes metamorphosis. The methodology described here can be applied to the study of different developmental stages, tissues, and subcellular structures in Drosophila or other model organisms. https://www.jove.com/v/60282 505 2020-06-02T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62285.jpg RBDT: A Computerized Task System based in Transposition for the Continuous Analysis of Relational Behavior Dynamics in Humans RBDT integrates behavioral patterns based on discrete responses (e.g., stimuli selection, placement of figures) and continuous responses (e.g., tracking of cursor movements, figure dragging) to study relational behavior with humans. RBDT is a challenging task based on transposition, in which the participant sets up stimuli compounds with a relational criterion (more/less than). https://www.jove.com/v/62285 669 2021-07-17T20:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67031.jpg Advancing Dyslexia Assessment in Children Through Computerized Testing The Multimedia Battery for Assessment of General-Domain and Specific-Domain Skills in Reading is a reliable and valid multimedia battery designed to assess cognitive and basic reading skills. It enables the generation of a comprehensive cognitive and reading performance profile, which is particularly beneficial for children with dyslexia. https://www.jove.com/v/67031 540 2024-08-16T21:00:00+00:00 JoVE no https://visualize.jove.com/34985758-a-txtl-based-assay-to-rapidly-identify-pams-for-crispr-cas-systems-with-multi-protein-effector-complexes monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10817.jpg CRISPR Genome editing technologies allow scientists to modify an organism’s DNA via the addition, removal, or rearrangement of genetic material at specific genomic locations. These types of techniques could potentially be used to cure genetic disorders such as hemophilia and sickle cell anemia. One popular and widely used DNA-editing research tool that could lead to safe and effective cures for genetic disorders is the CRISPR-Cas9 system. CRISPR-Cas9 stands for Clustered Regularly Interspaced Short... https://www.jove.com/v/10817 119 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50369.jpg A Multiplexed Luciferase-based Screening Platform for Interrogating Cancer-associated Signal Transduction in Cultured Cells Achieving a systems level understanding of cellular processes is a goal of modern-day cell biology. We describe here strategies for multiplexing luciferase reporters of various cellular function end-points to interrogate gene function using genome-scale RNAi... https://www.jove.com/v/50369 613 11300 2013-07-03T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64833.jpg DNA Virus Detection System Based on RPA-CRISPR/Cas12a-SPM and Deep Learning We present a protocol that combines recombinase polymerase amplification with a CRISPR/Cas12a system for trace detection of DNA viruses and builds portable smartphone microscopy with an artificial intelligence-assisted classification for point-of-care DNA virus... https://www.jove.com/v/64833 257 943 2024-05-10T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66703.jpg Author Spotlight: Development of Simplified CRISPR-Based Tests for Rapid Detection of Infectious Diseases Here, we present the step-by-step preparation of premixed, lyophilized recombinase-based isothermal amplification and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-based reactions, which can be used for the detection of nucleic acid biomarkers of infectious disease pathogens or other genetic markers of interest. https://www.jove.com/v/66703 616 1500 2024-08-16T12:40:00+00:00 JoVE no https://visualize.jove.com/35006955-optimization-of-cortisol-selective-molecularly-imprinted-polymers-enabled-by-molecular-dynamics-simulations monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17253/17253_article_thumb_17253.jpg Site-Targeted Drug Delivery Systems: Polymeric Carriers Polymeric carriers enhance targeted drug delivery by increasing efficacy while minimizing off-target effects. These carriers comprise a biodegradable polymeric backbone integrated with functional elements that enable targeting, improve physicochemical properties, and regulate drug release.Targeting MechanismsThe targeting ability of polymeric carriers is mediated by a homing device, which is a molecular recognition component designed to selectively bind to specific tissues or cells. Monoclonal... https://www.jove.com/v/17253 84 2026-02-12T11:17:27+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52545.jpg A Method for Selecting Structure-switching Aptamers Applied to a Colorimetric Gold Nanoparticle Assay A protocol is provided to select structure-switching aptamers for small molecule targets based on a tunable stringency magnetic bead selection method. Aptamers selected with structure-switching properties are beneficial for assays that require a conformational change to signal the presence of a target, such as the described gold nanoparticle... https://www.jove.com/v/52545 751 15300 2015-02-28T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57208.jpg Ultrasensitive Detection of Biomarkers by Using a Molecular Imprinting Based Capacitive Biosensor Here, we present a protocol for the detection and quantification of low abundant molecules in complex solutions using molecular imprinting in combination with a capacitance... https://www.jove.com/v/57208 502 12200 2018-02-16T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66605.jpg Author Spotlight: In Silico Creation and Impact of Carbonylated Amino Acids on Protein Structure and Function Here, we describe a protocol for the optimization and parameterization of amino acid residues modified with reactive carbonyl species, adaptable to protein systems. The protocol steps include structure design and optimization, charge assignments, parameter construction, and preparation of protein... https://www.jove.com/v/66605 357 550 2024-04-26T14:30:00+00:00 JoVE no https://visualize.jove.com/35027527-descriptive-analysis-of-the-mobile-applications-for-registering-and-monitoring-the-adverse-effects-of-antineoplastic-drugs-according-to-the-evaluation-methodology-of-iisyscorei-and-the-tic-salut-social-foundation monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14384.jpg Pharmacovigilance Post-marketing surveillance is a critical component of pharmaceutical regulation, often uncovering unanticipated adverse drug reactions (ADRs) once a drug is widely used over an extended period. This process, termed pharmacovigilance, aims to detect, evaluate, and minimize harmful effects related to medication use. The data collection for pharmacovigilance depends on spontaneous reporting systems, where healthcare professionals or patients voluntarily report suspected ADRs. In some cases, there... https://www.jove.com/v/14384 79 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16484.jpg Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches Biopharmaceutical studies constitute a vital field aiming to enhance drug delivery methods and refine therapeutic approaches, drawing upon diverse interdisciplinary knowledge. In research methodologies, the choice between controlled and non-controlled studies significantly influences the study's reliability and accuracy. Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast, controlled... https://www.jove.com/v/16484 83 JoVE no https://cloudfront.jove.com/files/ftp_upload/17188/17188_article_thumb_17188.jpg Therapeutic Drug Monitoring: Overview and Classification Therapeutic Drug Monitoring (TDM) is a clinical practice that measures specific drug levels in a patient's blood at designated intervals to ensure the drug concentration stays within a therapeutic range. This monitoring is crucial for optimizing individual dosage regimens, enhancing therapeutic efficacy, and minimizing drug-related toxicity. TDM is vital for drugs with narrow therapeutic windows, significant variability in pharmacokinetics, and a clear correlation between plasma levels and... https://www.jove.com/v/17188 76 2025-10-03T14:00:28+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17189/17189_article_thumb_17189.jpg Therapeutic Drug Monitoring: Affecting Factors Therapeutic Drug Monitoring (TDM) is the clinical practice of measuring specific drug levels in a patient's blood or body tissues to manage and optimize therapy. TDM is crucial for drugs with narrow therapeutic windows, like warfarin and phenytoin, where incorrect doses can lead to treatment failure or severe side effects. This monitoring ensures the dosage administered is within a safe and effective range. The factors affecting therapeutic drug monitoring include:Patient-Specific Factors:a. https://www.jove.com/v/17189 89 2025-10-03T14:00:19+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17190/17190_article_thumb_17190.jpg Therapeutic Drug Monitoring: Drug Analysis Methods Therapeutic Drug Monitoring (TDM) is a clinical practice that measures specific drug levels in a patient's blood or body tissues to tailor drug therapy effectively. This monitoring is critical for managing drugs with narrow therapeutic indices like digoxin and phenytoin, ensuring they are both safe and effective. For instance, monitoring theophylline levels in asthma patients involves precision and sensitivity to adjust doses according to individual responses to therapy, ensuring efficacy and... https://www.jove.com/v/17190 86 2025-10-03T14:00:18+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61899.jpg Digital Home-Monitoring of Patients after Kidney Transplantation: The MACCS Platform The MACCS platform is a comprehensive telemedicine concept aiming at better outcomes after kidney transplantation by sharing key medical information between patients and physicians. A telemedicine team reviews incoming data to detect potential complications and to improve adherence in kidney transplant recipients to achieve better long-term outcomes. https://www.jove.com/v/61899 433 2021-04-12T19:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62032.jpg Iterative Development of an Innovative Smartphone-Based Dietary Assessment Tool: Traqq This article describes the protocol for the development of an innovative smartphone-based dietary assessment application Traqq, including expert evaluations and usability testing. https://www.jove.com/v/62032 294 2021-03-19T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65810.jpg A Point-of-Care Method with Integrated Decision Support Tool to Estimate Anemia at Population Level An accurate hemoglobin estimation method is lacking at the point of care and may hinder population-based programs for treating anemia. Therefore, we developed a point-of-care method based on pooled capillary blood and an auto-analyzer integrated into a custom software application to categorize the hemoglobin values into different grades of anemia. https://www.jove.com/v/65810 335 2024-01-19T21:20:00+00:00 JoVE no https://visualize.jove.com/35079505-a-ruptured-anterior-communicating-artery-aneurysm-with-infra-optic-course-of-the-anterior-cerebral-artery-a-case-report-and-a-short-review monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1294.jpg Microsurgical Clip Obliteration of Middle Cerebral Aneurysm Using Intraoperative Flow Assessment Description of the surgical obliteration of a cerebral aneurysm utilizing an ultrasonic flow probe to assess arterial flow prior to and after aneurysm clip... https://www.jove.com/v/1294 1130 13800 2009-09-25T15:10:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14480.jpg Glaucoma: Overview Glaucoma is an eye condition characterized by increased intraocular pressure that damages the retina and optic nerve, leading to irreversible blindness if left untreated. The human eye has various components, including the cornea, iris, pupil, lens, and optic nerve. Aqueous humor is secreted by the epithelium of the ciliary body in the posterior chamber and flows through the trabecular meshwork and canal of Schlemm, maintaining normal intraocular pressure. The trabecular meshwork and the canal... https://www.jove.com/v/14480 85 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15309.jpg The Arch of Aorta The coronary arteries, originating from the ascending aorta, bifurcate from two sinuses located within the ascending aorta. Positioned just above the aortic semilunar valve, these sinuses house essential aortic baroreceptors and chemoreceptors, crucial for maintaining cardiac function. The left coronary artery and the right coronary artery branch off from the left posterior and anterior aortic sinuses, respectively. Encircling the heart, the coronary arteries form a ring-like structure before... https://www.jove.com/v/15309 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15312.jpg Arteries of the Head and Neck The human body's intricate network of arteries ensures that every organ system receives the necessary oxygen and nutrients for optimal function. The arterial network in the head and neck region is particularly complex, providing vital blood flow to the brain, eyes, and other critical structures. Prominent arteries in this region include the internal carotid arteries and the vertebral arteries. The internal carotid arteries supply blood to the anterior portion of the cerebrum. They enter the... https://www.jove.com/v/15312 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/17979/17979_article_thumb_17979.jpg Aneurysm I: Introduction An aortic aneurysm is a localized outpouching or dilation at a weak point in the artery wall. It may involve different parts of the aorta, such as the abdominal aorta, aortic arch, or thoracic aorta.Etiological factorsSeveral disorders are associated with aortic aneurysms.Congenital causes, such as primary connective tissue disorders like Marfan syndrome, impact the integrity and strength of connective tissues, notably affecting the aorta. Marfan syndrome is a genetic disorder that specifically... https://www.jove.com/v/17979 90 2025-06-19T16:19:01+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17980/17980_article_thumb_17980.jpg Aneurysm II: Clinical Manifestations and Diagnostic Studies Thoracic, aortic arch and abdominal aneurysms are significant vascular conditions that can present with various clinical manifestations and lead to serious complications. Understanding these manifestations and the appropriate diagnostic studies is essential for effective management and treatment.Thoracic Aortic AneurysmsThoracic aortic aneurysms often remain asymptomatic until they reach a size that impinges on adjacent structures. They typically cause deep, diffuse chest pain that radiates to... https://www.jove.com/v/17980 81 2025-06-19T16:19:14+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17981/17981_article_thumb_17981.jpg Aneurysm III: Interprofessional Care Aneurysm management involves either conservative medical therapy or surgical intervention, depending on the size and symptoms of the aneurysm. Conservative management is generally reserved for smaller, asymptomatic aneurysms, while larger or symptomatic aneurysms often necessitate surgical repair.Conservative Medical TherapyFor small, asymptomatic aneurysms, particularly abdominal aortic aneurysms (AAA) less than 5.5 centimeters in diameter, conservative medical therapy is recommended. This... https://www.jove.com/v/17981 86 2025-06-19T16:19:25+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51661.jpg Minimally Invasive Thumb-sized Pterional Craniotomy for Surgical Clip Ligation of Unruptured Anterior Circulation Aneurysms Minimally invasive thumb-sized pterional craniotomy for aneurysm clipping has afforded our patients with a shorter hospital stay at a lower cost compared to the national... https://www.jove.com/v/51661 718 15700 2015-08-11T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66720.jpg Optimization of the Longa Middle Cerebral Artery Occlusion Method for Complete Reperfusion This protocol presents a step-by-step guide for researchers to perform the middle cerebral artery occlusion procedure on mice using the modified Longa external carotid artery method. Modifications presented in this article aim to increase the accuracy of middle cerebral artery occlusion and ensure complete... https://www.jove.com/v/66720 798 1300 2024-11-22T13:00:00+00:00 JoVE no https://visualize.jove.com/35267657-advancements-in-oncology-with-artificial-intelligence-a-review-article monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12079.jpg Adaptive Mechanisms in Cancer Cells Cancer cells accumulate genetic changes at an abnormally rapid rate due to the defects in the DNA repair mechanisms. From an evolutionary perspective, such genetic instability is advantageous for cancer development. Mutant cell lines accumulate a series of beneficial mutations that contribute to their progression into cancer. Some of the advantages that cancer cells have on normal cells include - enhanced ability to divide without terminally differentiating, induce new blood vessel formation,... https://www.jove.com/v/12079 173 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12091.jpg Targeted Cancer Therapies The targeted cancer therapies, also known as “molecular targeted therapies,” take advantage of the molecular and genetic differences between the cancer cells and the normal cells. It needs a thorough understanding of the cancer cells to develop drugs that can target specific molecular aspects that drive the growth, progression, and spread of cancer cells without affecting the growth and survival of other normal cells in the body. There are several types of targeted therapies against specific... https://www.jove.com/v/12091 177 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12093.jpg Combination Therapies and Personalized Medicine Combining two or more treatment methods increases the life span of cancer patients while reducing damage to vital organs or tissue from the overuse of a single treatment. Combination therapy also targets different cancer-inducing pathways, thus reducing the chances of developing resistance to treatment. The combination of the drug acetazolamide and sulforaphane is a good example of combination therapy to treat cancer. The cells in the interior of a large tumor often die due to the hypoxic and... https://www.jove.com/v/12093 170 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12979.jpg Issues And Trends In Healthcare Delivery System The issues and trends in healthcare delivery are constantly changing. The COVID-19 pandemic is one recent issue that wreaked havoc on healthcare systems, causing a shortage of healthcare workers, high demand for medicines and supplies, and increased medical expenditure due to a lack of insurance. Other issues include rising healthcare costs and care fragmentation. Cost Containment Payment for healthcare services has historically promoted adoption of costly and often unnecessary or inefficient... https://www.jove.com/v/12979 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12079.jpg Adaptive Mechanisms in Cancer Cells Cancer cells accumulate genetic changes at an abnormally rapid rate due to the defects in the DNA repair mechanisms. From an evolutionary perspective, such genetic instability is advantageous for cancer development. Mutant cell lines accumulate a series of beneficial mutations that contribute to their progression into cancer. Some of the advantages that cancer cells have on normal cells include - enhanced ability to divide without terminally differentiating, induce new blood vessel formation,... https://www.jove.com/v/13443 173 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17623.jpg Cancer Survival Analysis Cancer survival analysis focuses on quantifying and interpreting the time from a key starting point, such as diagnosis or the initiation of treatment, to a specific endpoint, such as remission or death. This analysis provides critical insights into treatment effectiveness and factors that influence patient outcomes, helping to shape clinical decisions and guide prognostic evaluations. A cornerstone of oncology research, survival analysis tackles the challenges of skewed, non-normally... https://www.jove.com/v/17623 81 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58382.jpg Predicting Treatment Response to Image-Guided Therapies Using Machine Learning: An Example for Trans-Arterial Treatment of Hepatocellular Carcinoma Intra-arterial therapies are the standard of care for patients with hepatocellular carcinoma who cannot undergo surgical resection. A method for predicting response to these therapies is proposed. The technique uses pre-procedural clinical, demographic, and imaging information to train machine learning models capable of predicting response prior to... https://www.jove.com/v/58382 249 8400 2018-10-10T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68083.jpg Detection and Isolation of Cancer in Prostate Biopsies Using Stimulated Raman Histology and Artificial Intelligence Here, we present a standardized protocol for detecting prostate cancer using stimulated Raman histology (SRH) on biopsy samples due to advantages over traditional histopathology, focusing on sample preparation, imaging, and artificial intelligence to improve the cancer-to-tissue ratio. Additionally, it supports biobanking for transcriptomics, organoid or xenograft models, and identification of intraoperative surgical... https://www.jove.com/v/68083 485 714 2025-06-10T12:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68270.jpg Introduction of an Integrated Pathology Image Management, Artificial Intelligence, and Reporting System Integrated image management, artificial intelligence (AI), and reporting systems have revolutionized diagnostic pathology practice. In this paper, we introduce FlexLIS, a state-of-the-art system that enables AI to assist pathologists in performing histopathology image assessments and generating diagnostic reports. https://www.jove.com/v/68270 333 329 2025-07-11T15:40:00+00:00 JoVE no https://visualize.jove.com/35297766-contributions-of-artificial-intelligence-reported-in-obstetrics-and-gynecology-journals-systematic-review monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12958.jpg Current Trends in Nursing II Trends in nursing are multifactorial and associated with changes in society, within the nursing profession, and in other professions. Notably, telehealth and remote nursing contribute to successful healthcare delivery for numerous patients and help reduce stress for nurses due to nursing shortages. Nurses can reach patients, monitor their conditions, and interact with them using computers, audio, visual accessories, and telephones—for example, remote patient monitoring systems. Likewise,... https://www.jove.com/v/12958 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12979.jpg Issues And Trends In Healthcare Delivery System The issues and trends in healthcare delivery are constantly changing. The COVID-19 pandemic is one recent issue that wreaked havoc on healthcare systems, causing a shortage of healthcare workers, high demand for medicines and supplies, and increased medical expenditure due to a lack of insurance. Other issues include rising healthcare costs and care fragmentation. Cost Containment Payment for healthcare services has historically promoted adoption of costly and often unnecessary or inefficient... https://www.jove.com/v/12979 89 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57328.jpg Model Surgical Training: Skills Acquisition in Fetoscopic Laser Photocoagulation of Monochorionic Diamniotic Twin Placenta Using Realistic Simulators Practicing the specific skills required for fetoscopic laser coagulation of monochorionic placental anastomoses on realistic models can aid less experienced surgeons in overcoming the steep learning curve associated with this procedure that is now regarded as the standard of care for twin-twin transfusion... https://www.jove.com/v/57328 591 19900 2018-03-21T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58410.jpg Introduction of Intracapsular Rotary-cut Procedures IRCP: A Modified Hysteromyomectomy Procedures Facilitating Fertility Preservation Here, we present a protocol for performing an intracapsular rotary-cut procedure (IRCP), a modified laparoscopic intracapsular myomectomy that promotes fertility... https://www.jove.com/v/58410 346 10100 2019-01-17T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64763.jpg Methods for Studying Uterine Contributions to Pregnancy Establishment in an Ovariectomized Mouse Model Pregnancy establishment is a dynamic process involving complex embryo and uterine crosstalk. The precise contributions of the maternal uterine environment to these processes remain an active area of investigation. Here, detailed protocols are provided to aid in designing in vivo animal models to address these research questions. https://www.jove.com/v/64763 409 1800 2023-04-07T12:50:00+00:00 JoVE no https://visualize.jove.com/35358720-artificial-intelligence-in-brain-mri-analysis-of-alzheimers-disease-over-the-past-12-years-a-systematic-review monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15204.jpg Alzheimer's Disease: Overview Alzheimer's Disease (AD) is a continually advancing neurodegenerative disorder, distinguished by escalating memory loss, cognitive dysfunction, and dementia. The disease unfolds in three stages: preclinical, mild cognitive impairment (MCI), and dementia. Its onset is insidious, and the progression gradual, with the cause not well explained by other disorders. The clinical diagnosis of AD hinges on the presence of memory and other cognitive impairments. Biomarkers, such as changes in Aβ and tau... https://www.jove.com/v/15204 86 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50887.jpg Lesion Explorer: A Video-guided, Standardized Protocol for Accurate and Reliable MRI-derived Volumetrics in Alzheimer's Disease and Normal Elderly Lesion Explorer (LE) is a semi-automatic, image-processing pipeline developed to obtain regional brain tissue and subcortical hyperintensity lesion volumetrics from structural MRI of Alzheimer's disease and normal elderly. To ensure a high level of accuracy and reliability, the following is a video-guided, standardized protocol for LE's manual... https://www.jove.com/v/50887 770 40400 2014-04-14T16:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56015.jpg Application of Granger Causality Analysis of the Directed Functional Connection in Alzheimer's Disease and Mild Cognitive Impairment Based on resting-state functional magnetic resonance imaging with Granger causality analysis, we investigated the alterations in the directed functional connectivity between the posterior cingulate cortex and whole brain in patients with Alzheimer's Disease (AD), patients with Mild Cognitive Impairment (MCI), and healthy... https://www.jove.com/v/56015 523 8000 2017-08-07T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67574.jpg Hybrid PET/MRI Imaging of Alzheimer's Disease Based on 18 F-AV-1451 This protocol describes the use of 18F-AV-1451 PET/MRI to reveal tau pathology and neurodegeneration, aiding neurologists in diagnosing Alzheimer's disease, assessing its severity, and gaining insights into its progression and underlying pathological... https://www.jove.com/v/67574 317 379 2025-04-18T13:00:00+00:00 JoVE no https://visualize.jove.com/35438458-artificial-intelligence-algorithms-in-diabetic-retinopathy-screening monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40911/40911_article_thumb_40911.jpg Diabetic Retinopathy DefinitionDiabetic retinopathy is a microvascular complication of diabetes affecting the retinal blood vessels.Risk FactorsDiabetic retinopathy is present in almost all individuals with type 1 diabetes and more than 60% of those with type 2 diabetes after two decades of disease.The risk increases with poor glycemic control, hypertension, dyslipidemia, smoking, pregnancy, and puberty.Although cataracts and glaucoma are also more frequent in people with diabetes, retinopathy remains the leading... https://www.jove.com/v/40911 87 2026-04-13T14:37:50+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56137.jpg Using Retinal Imaging to Study Dementia The retina shares prominent similarities with the brain and thus represents a unique window to study vasculature and neuronal structure in the brain non-invasively. This protocol describes a method to study dementia using retinal imaging techniques. This method can potentially aid in diagnosis and risk assessment of... https://www.jove.com/v/56137 557 21800 2017-11-06T17:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61806.jpg Behavioral Assessment of Visual Function via Optomotor Response and Cognitive Function via Y-Maze in Diabetic Rats Neural degeneration in both eyes and brain as a result of diabetes can be observed through behavioral tests carried out on rodents. The Y-maze, a measure of spatial cognition, and the optomotor response, a measure of visual function, both provide insight into potential diagnoses and... https://www.jove.com/v/61806 461 6100 2020-10-23T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66123.jpg Author Spotlight: Understanding Retinal Vessel Resilience and Disease Progression A protection assay was developed to monitor the retinal vasculature's resilience to death from diabetes/diabetic retinopathy-related insults such as oxidative stress and cytokines. https://www.jove.com/v/66123 276 1200 2024-01-12T14:05:00+00:00 JoVE no https://visualize.jove.com/35455005-radiomics-based-artificial-intelligence-differentiation-of-neurodegenerative-diseases-with-reference-to-the-volumetry monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13865.jpg Magnetic Resonance Imaging Magnetic resonance imaging (MRI) is a noninvasive medical imaging technique based on a phenomenon of nuclear physics discovered in the 1930s, in which matter exposed to magnetic fields and radio waves was found to emit radio signals. In 1970, a physician and researcher named Raymond Damadian noticed that malignant (cancerous) tissue gave off different signals than normal body tissue. He applied for a patent for the first MRI scanning device in clinical use by the early 1980s. The early MRI... https://www.jove.com/v/13865 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17752.jpg Brain Imaging Brain imaging technologies provide critical insights into both the structure and function of the human brain, enabling medical professionals and researchers to diagnose, study, and treat neurological disorders or psychiatric disorders more effectively. These technologies include computerized axial tomography (CAT or CT scans), positron-emission tomography (PET scans), magnetic resonance imaging (MRI), functional magnetic resonance imaging (fMRI), and Transcranial Magnetic Stimulation (TMS).<br... https://www.jove.com/v/17752 74 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50319.jpg Identification of Disease-related Spatial Covariance Patterns using Neuroimaging Data Multivariate techniques including principal component analysis (PCA) have been used to identify signature patterns of regional change in functional brain images. We have developed an algorithm to identify reproducible network biomarkers for the diagnosis of neurodegenerative disorders, assessment of disease progression, and objective evaluation of treatment effects in patient... https://www.jove.com/v/50319 867 15800 2013-06-26T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50427.jpg Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases Diffusion tensor imaging (DTI) basically serves as an MRI-based tool to identify in vivo the microstructure of the brain and pathological processes due to neurological disorders within the cerebral white matter. DTI-based analyses allow for application to brain diseases both at the group level and in single subject... https://www.jove.com/v/50427 573 28600 2013-07-28T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50887.jpg Lesion Explorer: A Video-guided, Standardized Protocol for Accurate and Reliable MRI-derived Volumetrics in Alzheimer's Disease and Normal Elderly Lesion Explorer (LE) is a semi-automatic, image-processing pipeline developed to obtain regional brain tissue and subcortical hyperintensity lesion volumetrics from structural MRI of Alzheimer's disease and normal elderly. To ensure a high level of accuracy and reliability, the following is a video-guided, standardized protocol for LE's manual... https://www.jove.com/v/50887 770 40400 2014-04-14T16:45:00+00:00 JoVE no https://visualize.jove.com/35547656-the-research-and-development-thinking-on-the-status-of-artificial-intelligence-in-traditional-chinese-medicine monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12979.jpg Issues And Trends In Healthcare Delivery System The issues and trends in healthcare delivery are constantly changing. The COVID-19 pandemic is one recent issue that wreaked havoc on healthcare systems, causing a shortage of healthcare workers, high demand for medicines and supplies, and increased medical expenditure due to a lack of insurance. Other issues include rising healthcare costs and care fragmentation. Cost Containment Payment for healthcare services has historically promoted adoption of costly and often unnecessary or inefficient... https://www.jove.com/v/12979 89 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65139.jpg Author Spotlight: Optimization of Processing Technology for Tiebangchui with Zanba Based on CRITIC Combined with Box-Behnken Response Surface Method The present protocol describes an efficient and standard detoxification processing method for Zanba-stir-fried Tiebangchui using CRITIC combined with the Box-Behnken response surface... https://www.jove.com/v/65139 556 1200 2023-05-12T13:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65140.jpg Objectification of Tongue Diagnosis in Traditional Medicine, Data Analysis, and Study Application The present study employed U-Net and other deep learning algorithms to segment a tongue image and compared the segmentation results to investigate the objectification of tongue... https://www.jove.com/v/65140 356 2700 2023-04-14T14:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66552.jpg Author Spotlight: Exploring Sex-Specific Glial Signatures and Therapeutic Leads for Alzheimer's Disease This study analyzed single-nuclei transcriptomes of thirty-three individuals with Alzheimer's disease (AD), revealing sex-specific DEGs in glial cells. Functional enrichment analysis highlighted synaptic, neural, and hormone-related pathways. Key genes, namely NLGN4Y and its regulators, were identified, and potential therapeutic candidates for gender-specific AD were... https://www.jove.com/v/66552 262 994 2024-05-20T15:00:00+00:00 JoVE no https://visualize.jove.com/35548742-retracted-article-asic1a-involves-acidic-microenvironment-induced-activation-and-autophagy-of-pancreatic-stellate-cells monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11963.jpg Autophagy Autophagy is a self-digesting process by which a cell protects itself from threats both within and outside the cell, ranging from abnormal proteins to invading bacteria. In this process, obsolete components of the cell and invading microbes are degraded by hydrolytic enzymes active in an acidic environment of the lysosomal lumen. An autophagic pathway consists of a series of signaling events activated in response to diverse stress and physiological conditions such as food deprivation,... https://www.jove.com/v/11963 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16425.jpg Gastritis-II: Pathophysiology Gastritis is marked by disruption of the mucosal barrier that usually protects the stomach tissue from digestive juices and manifests in acute and chronic forms. In acute gastritis, the gastric mucosa becomes swollen and red and undergoes superficial erosion. Superficial ulceration may lead to bleeding. In chronic gastritis, persistent or repeated insults lead to chronic inflammatory changes and, eventually, thinning or atrophy of the gastric tissue. Gastritis can stem from various causes, each... https://www.jove.com/v/16425 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16436.jpg Chronic Pancreatitis I: Introduction The pancreas, an elongated and flat gland situated behind the stomach, serves a vital function in digesting food and managing blood sugar levels. Pancreatitis is the inflammation of the pancreas, which occurs when the immune system becomes active and causes swelling, pain, and disruptions in organ function. Pancreatitis can manifest as either an acute or chronic condition. Acute pancreatitis arises suddenly and lasts for a brief duration, while chronic pancreatitis is a long-term affliction... https://www.jove.com/v/16436 84 JoVE no https://cloudfront.jove.com/files/ftp_upload/41022/41022_article_thumb_41022.jpg Acute Pancreatitis II: Pathophysiology The pathophysiology of acute pancreatitis centers on injury to pancreatic acinar cells, which initiates a cascade of harmful intracellular events.This injury leads to premature activation of trypsinogen to trypsin in the pancreas. Trypsin then activates other digestive enzymes, such as chymotrypsin, elastase, and phospholipase A2, which begin breaking down pancreatic tissue. The resulting autodigestion causes local inflammation, tissue swelling, hemorrhage, and fat necrosis.Injured acinar cells... https://www.jove.com/v/41022 81 2026-04-15T08:50:15+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/41023/41023_article_thumb_41023.jpg Chronic Pancreatitis I: Introduction Chronic pancreatitis is a long-standing, relapsing inflammation of the pancreas, characterized by irreversible damage to the gland. It results in progressive destruction of the pancreatic parenchyma, fibrosis, and eventual loss of both exocrine and endocrine function. The disease may evolve gradually after multiple episodes of acute pancreatitis or develop independently.EtiologyChronic pancreatitis can arise from a variety of causes:Alcohol use is the leading cause, accounting for 70–80% of... https://www.jove.com/v/41023 85 2026-04-15T08:47:40+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/41024/41024_article_thumb_41024.jpg Chronic Pancreatitis II: Pathophysiology Chronic pancreatitis is a progressive and irreversible inflammation of the pancreas, most often caused by long-term alcohol abuse, but it can also be related to ductal obstruction, smoking, or genetic factors.Chronic pancreatitis occurs when the pancreas is repeatedly exposed to harmful agents like alcohol, smoking, ductal obstruction, or genetic predisposition. These factors lead to the release of toxic metabolites and inflammatory cytokines, sustaining chronic inflammation in the pancreatic... https://www.jove.com/v/41024 81 2026-04-15T08:49:09+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50391.jpg Preparation of Pancreatic Acinar Cells for the Purpose of Calcium Imaging, Cell Injury Measurements, and Adenoviral Infection We describe a reproducible method of preparing mouse pancreatic acinar cells from a mouse for the purpose of examining acinar cell calcium signals and cellular injury with physiologically and pathologically relevant stimuli. A method for adenoviral infection of these cells is also... https://www.jove.com/v/50391 639 13400 2013-07-05T12:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65005.jpg Evaluating Autophagy Levels in Two Different Pancreatic Cell Models Using LC3 Immunofluorescence The goal of this protocol is to determine autophagic levels in pancreatic cancer and pancreatic acinar cells through LC3 immunofluorescence and LC3 dot... https://www.jove.com/v/65005 487 1600 2023-04-28T13:40:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66625.jpg Author Spotlight: Validating Cancer Therapy Responses with Desmoplastic Spheroid Models Pancreatic cancer remains one of the toughest cancers to treat. Therefore, it is critical that pre-clinical models evaluating treatment efficacy are reproducible and clinically relevant. This protocol describes a simple co-culture procedure to generate reproducible, clinically relevant desmoplastic... https://www.jove.com/v/66625 222 1600 2024-09-27T13:00:00+00:00 JoVE no https://visualize.jove.com/35550692-anticoagulation-for-percutaneous-ventricular-assist-device-supported-cardiogenic-shock-jacc-review-topic-of-the-week monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15305.jpg Blood Pressure Imbalances and Circulatory Shock Disorders affecting blood volume, vascular tone, or vascular function can disrupt vascular homeostasis, including conditions like hypertension, hemorrhage, and shock. Blood Pressure: Hypertension and Hypotension Normal blood pressure is 120/80 mm Hg. Elevated blood pressure is 120-129/under 80 mm Hg. Hypertension, warranting treatment at 130/80 mm Hg, is often asymptomatic and can lead to severe cardiovascular events, aneurysms, peripheral arterial disease, chronic renal disease, or cardiac... https://www.jove.com/v/15305 84 JoVE no https://cloudfront.jove.com/files/ftp_upload/17891/17891_article_thumb_17891.jpg Cardiac Catheterization IV: Nursing Management Nursing responsibilities before cardiac catheterization include:Assess for allergies and establish baseline health status.Before cardiac catheterization, assess the patient for allergies to contrast dye. Perform a comprehensive baseline assessment, including vital signs, heart and breath sounds, and a neurovascular assessment of the extremities, noting distal pulses, skin color, and temperature. Instruct the patient to fast for 8-12 hours before the procedure. Evaluate baseline laboratory... https://www.jove.com/v/17891 86 2025-06-19T16:15:06+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17905/17905_article_thumb_17905.jpg Aortic Regurgitation III: Medical Management Aortic regurgitation (AR) is when the aortic valve does not close or seal properly, leading to backward blood circulation from the aorta into the left ventricle during diastole. Common causes of AR include rheumatic heart disease, congenital valve defects, and aortic root dilation. Managing AR requires a multifaceted approach to alleviate symptoms, preserve left ventricular function, and address the underlying cause of the regurgitation. Patients with symptomatic AR or significant left... https://www.jove.com/v/17905 85 2025-06-19T16:20:54+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17932/17932_article_thumb_17932.jpg Acute Coronary Syndrome V: Nursing Management Nursing Assessment:Nursing management of acute coronary syndrome (ACS) involves taking the patient's history, focusing on primary complaints such as chest pain, dyspnea, and excessive sweating (diaphoresis), as well as other symptoms like back or jaw pain, nausea, vomiting, palpitations, dizziness, and fatigue. The nurse also reviews the patient's history of cardiac events, risk factors such as hypertension, diabetes, smoking, family history, and current medications.In the objective assessment,... https://www.jove.com/v/17932 86 2025-06-19T16:29:20+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17949/17949_article_thumb_17949.jpg Cardiopulmonary Resuscitation IV: Pharmacological Management Pharmacologic intervention is crucial in treating cardiac arrest patients during ACLS or Advanced Cardiovascular Life Support. The ACLS algorithms guide the administration of specific drugs based on the patient's cardiac arrest rhythm, which includes pulseless ventricular tachycardia (VT), ventricular fibrillation (VF), asystole, and pulseless electrical activity (PEA).EpinephrineIndication: Epinephrine is the first-line drug for all cardiac arrest rhythms.Mechanism of Action: Epinephrine... https://www.jove.com/v/17949 85 2025-07-31T20:24:37+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17962/17962_article_thumb_17962.jpg Cardiomyopathy V: Interprofessional Care Managing cardiomyopathy involves addressing underlying or precipitating causes, treating heart failure with medications, and implementing dietary changes and a balanced exercise and rest regimen.Lifestyle ModificationsCardiomyopathy patients should adopt a low-sodium diet to reduce fluid retention and manage heart failure. A personalized exercise and rest plan helps maintain physical fitness without overstraining the heart. Avoiding alcohol and tobacco is essential to prevent further damage to... https://www.jove.com/v/17962 89 2025-06-19T16:42:59+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62110.jpg Utilizing Percutaneous Ventricular Assist Devices in Acute Myocardial Infarction Complicated by Cardiogenic Shock Percutaneous ventricular assist devices are increasingly being utilized in patients with acute myocardial infarction and cardiogenic shock. Herein, we discuss the mechanism of action and hemodynamic effects of such devices. We also review algorithms and best practices for the implantation, management and weaning of these complex... https://www.jove.com/v/62110 370 3400 2021-06-12T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62140.jpg Use of a Percutaneous Ventricular Assist Device/Left Atrium to Femoral Artery Bypass System for Cardiogenic Shock The following article describes the stepwise procedure for placement of a device (e.g., Tandemheart) in cardiogenic shock (CS) that is a percutaneous left ventricular assist device (pLVAD) and a left atrial to femoral artery bypass (LAFAB) system that bypasses and supports the left ventricle (LV) in CS. https://www.jove.com/v/62140 459 3800 2021-08-16T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67731.jpg In Vitro Thrombosis Test for Ventricular Assist Devices We present a benchtop protocol to induce thrombosis in ventricular assist devices (VAD) within a recirculating test platform. This method serves to identify thrombogenic hotspots in the blood flow path and can help improve thromboresistance ahead of preclinical testing in animal... https://www.jove.com/v/67731 555 796 2025-03-21T13:30:00+00:00 JoVE no https://visualize.jove.com/35595728-structural-rearrangements-allow-nucleic-acid-discrimination-by-type-i-d-cascade monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/4401.jpg Analyzing and Building Nucleic Acid Structures with 3DNA The 3DNA software package is a popular and versatile bioinformatics tool with capabilities to analyze, construct, and visualize three-dimensional nucleic acid structures. This article presents detailed protocols for a subset of new and popular features available in 3DNA, applicable to both individual structures and ensembles of related... https://www.jove.com/v/4401 984 20700 2013-04-26T12:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11568.jpg Restarting Stalled Replication Forks DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a... https://www.jove.com/v/11568 157 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56221.jpg Sequence-specific and Selective Recognition of Double-stranded RNAs over Single-stranded RNAs by Chemically Modified Peptide Nucleic Acids We report the protocols for the synthesis and purification of Peptide Nucleic Acid (PNA) oligomers incorporating modified residues. The biochemical and biophysical methods for the characterization of the recognition of RNA duplexes by the modified PNAs are... https://www.jove.com/v/56221 544 9600 2017-09-21T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66461.jpg Author Spotlight: Advancements in DNA Nanosensors – Addressing Sensitivity and Selectivity Challenges in Molecular Detection The DNAzyme-based nanomachines can be used for highly selective and sensitive detection of nucleic acids. This article describes a detailed protocol for the design of DNAzyme-based nanomachines with a 10-23 core using free software and their application in the detection of an Epstein-Barr virus fragment as an... https://www.jove.com/v/66461 436 1100 2024-02-09T14:40:00+00:00 JoVE no https://visualize.jove.com/35731103-artificial-intelligence-ai-for-fracture-diagnosis-an-overview-of-current-products-and-considerations-for-clinical-adoption-from-the-iajri-special-series-on-ai-applications monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12979.jpg Issues And Trends In Healthcare Delivery System The issues and trends in healthcare delivery are constantly changing. The COVID-19 pandemic is one recent issue that wreaked havoc on healthcare systems, causing a shortage of healthcare workers, high demand for medicines and supplies, and increased medical expenditure due to a lack of insurance. Other issues include rising healthcare costs and care fragmentation. Cost Containment Payment for healthcare services has historically promoted adoption of costly and often unnecessary or inefficient... https://www.jove.com/v/12979 89 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63806.jpg Augmented Reality Navigation-Guided Core Decompression for Osteonecrosis of Femoral Head Augmented reality technology was applied to core decompression for osteonecrosis of the femoral head to realize real-time visualization of this surgical procedure. This method can effectively improve the safety and precision of core... https://www.jove.com/v/63806 377 3800 2022-04-12T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66014.jpg Author Spotlight: Advancing CBCT and Digital Dental Image Integration with AI-Assisted Digitization A process of registering cone-beam computed tomography scans and digital dental images has been presented using artificial intelligence (AI) -assisted identification of landmarks and merging. A comparison with surface-based registration shows that AI-based digitization and integration are reliable and... https://www.jove.com/v/66014 349 978 2024-02-23T13:35:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68270.jpg Introduction of an Integrated Pathology Image Management, Artificial Intelligence, and Reporting System Integrated image management, artificial intelligence (AI), and reporting systems have revolutionized diagnostic pathology practice. In this paper, we introduce FlexLIS, a state-of-the-art system that enables AI to assist pathologists in performing histopathology image assessments and generating diagnostic reports. https://www.jove.com/v/68270 333 217 2025-07-11T15:40:00+00:00 JoVE no https://visualize.jove.com/35775439-molecular-imprinting-as-a-simple-way-for-the-long-term-maintenance-of-the-stemness-and-proliferation-potential-of-adipose-derived-stem-cells-an-iin-vitroi-study monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11619.jpg Genomic Imprinting and Inheritance Diploid organisms inherit genetic material through chromosomes from both parents. Copies of the same gene are known as alleles. In most cases, both alleles are simultaneously expressed and allow various cellular processes to function optimally. If one of the alleles is missing or mutated, the expression of the other allele can compensate; however, this is not true for all genes. The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as... https://www.jove.com/v/11619 150 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52181.jpg Isolation and Enrichment of Human Adipose-derived Stromal Cells for Enhanced Osteogenesis The transcriptional heterogeneity within human adipose-derived stromal cells can be defined on the single cell level using cell surface markers and osteogenic genes. We describe a protocol utilizing flow cytometry for the isolation of cell subpopulations with increased osteogenic potential, which may be used to enhance craniofacial skeletal... https://www.jove.com/v/52181 660 11700 2015-01-12T14:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57804.jpg Isolation, Expansion, and Adipogenic Induction of CD34+CD31+ Endothelial Cells from Human Omental and Subcutaneous Adipose Tissue The differentiation of white and beige adipocytes from adipose tissue vascular progenitors bears potential for metabolic improvement in obesity. We describe protocols for a CD34+CD31+ endothelial cell isolation from human fat and for a subsequent in vitro expansion and differentiation into white and beige adipocytes. Several downstream applications are... https://www.jove.com/v/57804 628 11900 2018-07-17T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63036.jpg Technique for Obtaining Mesenchymal Stem Cell from Adipose Tissue and Stromal Vascular Fraction Characterization in Long-Term Cryopreservation The present protocol describes an improved methodology for ADSC isolation resulting in a tremendous cellular yield with time gain compared to the literature. This study also provides a straightforward method for obtaining a relatively large number of viable cells after long-term... https://www.jove.com/v/63036 357 3400 2021-12-30T16:00:00+00:00 JoVE no https://visualize.jove.com/36010229-automatic-acne-object-detection-and-acne-severity-grading-using-smartphone-images-and-artificial-intelligence monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40820/40820_article_thumb_40820.jpg Acne Infection Acne is a multifactorial skin condition primarily affecting adolescents and young adults, with a global prevalence estimated to exceed 75% in this demographic. The condition is characterized by the formation of comedones (blackheads and whiteheads), papules, pustules, nodules, and, in severe cases, cysts, particularly in areas rich in sebaceous glands such as the face, neck, chest, and back. The pathogenesis involves increased sebum production, follicular hyperkeratinization, colonization by... https://www.jove.com/v/40820 87 2026-03-12T20:35:45+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62521.jpg Artificial Intelligence Approaches to Assessing Primary Cilia The use of artificial intelligence (Ai) to analyze images is emerging as a powerful, less biased, and rapid approach compared with commonly used methods. Here we trained Ai to recognize a cellular organelle, primary cilia, and analyze properties such as length and staining intensity in a rigorous and reproducible manner. https://www.jove.com/v/62521 538 3600 2021-05-01T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65931.jpg Author Spotlight: Addressing Technical and Subjective Challenges in Measuring Classroom Attention This paper proposes an artificial intelligence-based system to automatically detect whether students are paying attention to the class or are distracted. This system is designed to help teachers maintain students' attention, optimize their lessons, and dynamically introduce modifications in order for them to be more... https://www.jove.com/v/65931 397 4000 2023-12-15T14:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68083.jpg Detection and Isolation of Cancer in Prostate Biopsies Using Stimulated Raman Histology and Artificial Intelligence Here, we present a standardized protocol for detecting prostate cancer using stimulated Raman histology (SRH) on biopsy samples due to advantages over traditional histopathology, focusing on sample preparation, imaging, and artificial intelligence to improve the cancer-to-tissue ratio. Additionally, it supports biobanking for transcriptomics, organoid or xenograft models, and identification of intraoperative surgical... https://www.jove.com/v/68083 485 169 2025-06-10T12:20:00+00:00 JoVE no https://visualize.jove.com/36120079-in-vivo-detection-of-cyclic-di-amp-in-istaphylococcus-aureusi monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/19461/19461_article_thumb_19461.jpg Differential Staining Technique Differential staining is an essential microbiological technique that exploits variations in cell wall structures to classify and identify microorganisms. It facilitates the distinction of bacteria, aiding in diagnostic and research applications. Two of the most widely used differential staining methods are Gram staining and acid-fast staining, both of which rely on the chemical and structural differences in bacterial cell walls.Gram Staining TechniqueGram staining differentiates bacteria by... https://www.jove.com/v/19461 86 2025-06-12T09:26:11+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50474.jpg Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria Lytic phage biosensors and antibody beads are able to discriminate between methicillin resistant (MRSA) and sensitive staphylococcus bacteria. The phages were immobilized by a Langmuir-Blodgett method onto a surface of a quartz crystal microbalance sensor and worked as broad range staphylococcus probes. Antibody beads recognize... https://www.jove.com/v/50474 844 24600 2013-05-08T09:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50779.jpg Multiplex PCR Assay for Typing of Staphylococcal Cassette Chromosome Mec Types I to V in Methicillin-resistant Staphylococcus aureus We demonstrate a simple multiplex PCR assay for quick-screening and typing of Staphylococcal Cassette Chromosome mec (SCCmec) types I-V for methicillin-resistant Staphylococcus aureus, and provide some of the vital steps and procedural nuances that make it successful for adapting this assay to individual... https://www.jove.com/v/50779 543 12000 2013-09-05T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55558.jpg A Tandem Liquid Chromatography–Mass Spectrometry-based Approach for Metabolite Analysis of Staphylococcus aureus Here we describe a protocol for the extraction of metabolites from Staphylococcus aureus and their subsequent analysis via liquid chromatography and mass... https://www.jove.com/v/55558 483 10200 2017-03-28T15:00:00+00:00 JoVE no https://visualize.jove.com/36140093-a-framework-for-biosensors-assisted-by-multiphoton-effects-and-machine-learning monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40786/40786_article_thumb_40786.jpg Microbial Biosensors Microbial biosensors are analytical devices that utilize living microbes to detect specific substances through measurable signals. These devices consist of two main components: biosensing organisms and signal-transducing elements. Biosensing organisms, such as Escherichia coli or Saccharomyces cerevisiae, are typically housed in multiwell plates connected to transducers, enabling rapid, real-time detection of target analytes.Signal Generation MechanismWhen a target analyte—such as... https://www.jove.com/v/40786 77 2026-03-12T13:35:55+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57902.jpg Analyzing Dynamic Protein Complexes Assembled On and Released From Biolayer Interferometry Biosensor Using Mass Spectrometry and Electron Microscopy Here we present a protocol to monitor the assembly and disassembly of the anthrax toxin using biolayer interferometry (BLI). Following assembly/disassembly on the biosensor surface, the large protein complexes are released from the surface for visualization and identification of components of the complexes using electron microscopy and mass spectrometry,... https://www.jove.com/v/57902 570 9500 2018-08-06T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63637.jpg Biomolecular Imaging of Cellular Uptake of Nanoparticles using Multimodal Nonlinear Optical Microscopy This article presents the integration of a spectral-focusing module and a dual-output pulse laser, enabling rapid hyperspectral imaging of gold nanoparticles and cancer cells. This work aims to demonstrate the details of multimodal nonlinear optical techniques on a standard laser scanning... https://www.jove.com/v/63637 433 2000 2022-05-16T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67906.jpg Multimodal Optical Imaging Platform for Studying Cellular Metabolism Utilizing a multimodal platform combining label-free optical imaging modalities, we have developed a protocol for visualizing and quantifying cellular dynamics and metabolism. Through imaging via multiphoton fluorescence, second harmonic generation, and stimulated Raman scattering microscopy, we can generate a holistic overview of the cellular and molecular... https://www.jove.com/v/67906 287 591 2025-06-06T13:35:00+00:00 JoVE no https://visualize.jove.com/36183997-towards-an-automated-approach-for-smart-sterility-test-examination monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13241.jpg Cleaning, Sterilization, and Disinfection Cleaning, disinfection, and sterilization are the methods that help to break the infection chain and prevent disease. Cleaning The cleaning process usually involves using water with detergents or enzymatic cleaner and removing foreign material from objects and surfaces, including organic material such as body fluids or inorganic material like soil. Cleaning is performed before high-level disinfection and sterilization because foreign materials on the cover of the devices interfere with process... https://www.jove.com/v/13241 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13242.jpg Methods of Sterilization I: Physical Methods As used in a healthcare facility, sterilization destroys all microorganisms through physical or chemical methods. The physical method includes steam, dry heat, boiling water, and radiation. Steam sterilization uses non-toxic, low-cost moist heat in the form of saturated steam under pressure, which is fast, microbicidal, and sporicidal, and quickly warms and penetrates fabrics. Autoclaves, or steam sterilizers, expose each item to direct steam contact for a predetermined time at the necessary... https://www.jove.com/v/13242 89 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13243.jpg Methods of Sterilization II: Chemical Methods In healthcare, the chemical method of sterilization uses chemical sterilants to treat surgical instruments and medical supplies to help prevent the transmission of infectious pathogens to patients. Due to heat sensitivity, most medical supplies and equipment should not be exposed to high temperatures. These parts include rubber, plastic, glass, and other similar elements. Using chemical sterilization rather than heat to clean out equipment is recommended. It eradicates and removes all bacteria,... https://www.jove.com/v/13243 90 JoVE no https://cloudfront.jove.com/files/ftp_upload/19597/19597_article_thumb_19597.jpg Key Techniques in Microbiology Aseptic techniques prevent contamination, ensure experimental accuracy, and protect researchers and microbial cultures. These techniques are essential in clinical, industrial, and research settings where sterility is required.Maintaining Sterility in Laboratory PracticesScientists maintain sterility by sterilizing tools with heat or chemicals, disinfecting work surfaces, and handling cultures in controlled environments. Working near an open flame or within a laminar flow hood reduces the risk... https://www.jove.com/v/19597 79 2026-02-11T10:41:06+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40816/40816_article_thumb_40816.jpg Automated Microbial Diagnostics Automated diagnostic analyzers have transformed clinical microbiology by providing rapid and reliable methods for pathogen identification and antibiotic susceptibility testing. Among these systems, the Vitek 2 is widely used because it automates the traditionally labor-intensive processes of microbial identification (ID) and antibiotic susceptibility testing (AST), delivering standardized and timely results that are essential for effective patient care.Microbial Identification with ID CardsThe... https://www.jove.com/v/40816 84 2026-03-12T13:35:56+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65209.jpg Author Spotlight: Microbial Control and Monitoring Strategies for Cleanroom Environments and Cellular Therapies The protocol summarizes the best practices to minimize microbial bioburden in a cleanroom environment and includes strategies such as environmental monitoring, process monitoring, and product sterility testing. It is relevant for manufacturing and testing facilities that are required to meet current good tissue practice standards and current good manufacturing practice standards. https://www.jove.com/v/65209 570 3600 2023-03-17T12:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66588.jpg Author Spotlight: Accelerating Diagnostic Accuracy with Direct Identification of Gram-Negatives from Blood Culture Bottles EUCAST has developed a direct antimicrobial susceptibility testing (AST) protocol for automated blood cultures. However, its dependence on mass spectrometry-based microbial identification can be obviated by using a direct inoculum preparation protocol in an automated microbial identification system. This approach can provide AST reports within 24 h of sample... https://www.jove.com/v/66588 547 1000 2024-05-24T13:40:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67706.jpg Comparative Analysis of Automatic Fecal Analyzer versus Direct Wet Smear Microscopy for Detecting Parasitic Infections in Stool Samples Parasitic infections pose a significant public health challenge, especially in developing countries and regions. This study compares an Automatic Fecal Analyzer to assess its diagnostic efficacy with that of the traditional Direct Wet Smear Microscopy... https://www.jove.com/v/67706 297 572 2025-04-25T13:30:00+00:00 JoVE no https://visualize.jove.com/36184672-label-free-enhancement-of-adrenal-gland-visualization-using-near-infrared-autofluorescence-for-surgical-guidance monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14986.jpg Anatomy of the Adrenal Glands The adrenal or supra-renal glands, situated above the kidneys and aligned with the twelfth rib, are paired pyramid-shaped structures crucial for the body's stress response. During stress, these glands secrete hormones vital for adaptive physiological reactions. These glands possess a distinctive yellow tinge due to the stored cholesterol and fatty acids required for hormone synthesis. They are encased in a fibrous capsule and cushioned by fat. The adrenal gland comprises two distinct regions... https://www.jove.com/v/14986 77 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51776.jpg Tissue-simulating Phantoms for Assessing Potential Near-infrared Fluorescence Imaging Applications in Breast Cancer Surgery Near-infrared fluorescence (NIRF) imaging may improve therapeutic outcome of breast cancer surgery by enabling intraoperative tumor localization and evaluation of surgical margin status. Using tissue-simulating breast phantoms containing fluorescent tumor-simulating inclusions, potential clinical applications of NIRF imaging in breast cancer patients can be assessed for standardization and training purposes. https://www.jove.com/v/51776 665 12300 2014-09-19T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58530.jpg Isolation, Fixation, and Immunofluorescence Imaging of Mouse Adrenal Glands Here we present a method to isolate adrenal glands from mice, fix the tissues, section them, and perform immunofluorescence... https://www.jove.com/v/58530 517 24200 2018-10-02T14:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67562.jpg The Role of Indocyanine Green Fluorescence in Complex Laparoscopic Cholecystectomy Navigation This protocol outlines the steps for fluorescence-guided laparoscopic cholecystectomy and elucidates the role of fluorescence navigation in diverse surgical... https://www.jove.com/v/67562 207 639 2025-01-31T13:50:00+00:00 JoVE no https://visualize.jove.com/36198112-evaluation-of-human-performance-aiding-live-synthetically-engineered-bacteria-in-a-gut-on-a-chip monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40783/40783_article_thumb_40783.jpg iChip The cultivation of environmental microorganisms has long been hindered by the inability to replicate complex native conditions in vitro. The isolation chip (iChip) addresses this limitation by facilitating the growth of previously uncultivable microorganisms through in situ incubation. Designed for high-throughput microbial cultivation, the iChip comprises hundreds of microchambers, each capable of housing a single microbial cell. These microchambers are loaded with a mixture of molten agar and... https://www.jove.com/v/40783 84 2026-03-12T13:36:06+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40786/40786_article_thumb_40786.jpg Microbial Biosensors Microbial biosensors are analytical devices that utilize living microbes to detect specific substances through measurable signals. These devices consist of two main components: biosensing organisms and signal-transducing elements. Biosensing organisms, such as Escherichia coli or Saccharomyces cerevisiae, are typically housed in multiwell plates connected to transducers, enabling rapid, real-time detection of target analytes.Signal Generation MechanismWhen a target analyte—such as... https://www.jove.com/v/40786 77 2026-03-12T13:35:55+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54344.jpg Co-culture of Living Microbiome with Microengineered Human Intestinal Villi in a Gut-on-a-Chip Microfluidic Device We describe an in vitro protocol to co-culture gut microbiome and intestinal villi for an extended period using a human gut-on-a-chip microphysiological... https://www.jove.com/v/54344 651 22600 2016-08-30T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65605.jpg Author Spotlight: Enhancing Understanding and Treatment Strategies with the NEC-on-a-Chip Model This protocol describes an in vitro model of necrotizing enterocolitis (NEC), which can be used for mechanistic studies into disease pathogenesis. It features a microfluidic chip seeded with intestinal enteroids derived from the human neonatal intestine, endothelial cells, and the intestinal microbiome of a neonate with severe NEC. https://www.jove.com/v/65605 411 1400 2023-07-28T12:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66603.jpg Author Spotlight: Developing Immunocompetent Organ-on-Chip Models for Infectious Disease Research Our detailed protocol outlines the creation and use of the advanced intestine-on-chip model, which simulates human intestinal mucosa with 3D structures and various cell types, enabling in-depth analysis of immune responses and cellular functions in response to microbial... https://www.jove.com/v/66603 528 1800 2024-05-24T14:10:00+00:00 JoVE no https://visualize.jove.com/36241586-artificial-intelligence-in-hematological-diagnostics-game-changer-or-gadget monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12979.jpg Issues And Trends In Healthcare Delivery System The issues and trends in healthcare delivery are constantly changing. The COVID-19 pandemic is one recent issue that wreaked havoc on healthcare systems, causing a shortage of healthcare workers, high demand for medicines and supplies, and increased medical expenditure due to a lack of insurance. Other issues include rising healthcare costs and care fragmentation. Cost Containment Payment for healthcare services has historically promoted adoption of costly and often unnecessary or inefficient... https://www.jove.com/v/12979 89 JoVE no https://cloudfront.jove.com/files/ftp_upload/40816/40816_article_thumb_40816.jpg Automated Microbial Diagnostics Automated diagnostic analyzers have transformed clinical microbiology by providing rapid and reliable methods for pathogen identification and antibiotic susceptibility testing. Among these systems, the Vitek 2 is widely used because it automates the traditionally labor-intensive processes of microbial identification (ID) and antibiotic susceptibility testing (AST), delivering standardized and timely results that are essential for effective patient care.Microbial Identification with ID CardsThe... https://www.jove.com/v/40816 84 2026-03-12T20:35:56+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57867.jpg Database-guided Flow-cytometry for Evaluation of Bone Marrow Myeloid Cell Maturation The MDS diagnosis is difficult in the absence of morphological criteria or non-informative cytogenetics. MFC could help refine the MDS diagnostic process. To become useful for clinical practice, the MFC analysis must be based on parameters with sufficient specificity and sensitivity, and data should be reproducible between different... https://www.jove.com/v/57867 725 11700 2018-11-03T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64549.jpg Automation of the Micronucleus Assay Using Imaging Flow Cytometry and Artificial Intelligence The micronucleus (MN) assay is a well-established test for quantifying DNA damage. However, scoring the assay using conventional techniques such as manual microscopy or feature-based image analysis is laborious and challenging. This paper describes the methodology to develop an artificial intelligence model to score the MN assay using imaging flow cytometry... https://www.jove.com/v/64549 551 2200 2023-01-27T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65557.jpg Author Spotlight: AI-Driven Trypanosome Species Detection from Microscopic Images Worldwide medical blood parasites were automatically screened using simple steps on a low-code AI platform. The prospective diagnosis of blood films was improved by using an object detection and classification method in a hybrid deep learning model. The collaboration of active monitoring and well-trained models helps to identify hotspots of trypanosome... https://www.jove.com/v/65557 500 1600 2023-10-27T13:50:00+00:00 JoVE no https://visualize.jove.com/36311999-everything-real-about-unreal-artificial-intelligence-in-diabetic-retinopathy-and-in-ocular-pathologies monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40911/40911_article_thumb_40911.jpg Diabetic Retinopathy DefinitionDiabetic retinopathy is a microvascular complication of diabetes affecting the retinal blood vessels.Risk FactorsDiabetic retinopathy is present in almost all individuals with type 1 diabetes and more than 60% of those with type 2 diabetes after two decades of disease.The risk increases with poor glycemic control, hypertension, dyslipidemia, smoking, pregnancy, and puberty.Although cataracts and glaucoma are also more frequent in people with diabetes, retinopathy remains the leading... https://www.jove.com/v/40911 87 2026-04-13T21:37:50+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56137.jpg Using Retinal Imaging to Study Dementia The retina shares prominent similarities with the brain and thus represents a unique window to study vasculature and neuronal structure in the brain non-invasively. This protocol describes a method to study dementia using retinal imaging techniques. This method can potentially aid in diagnosis and risk assessment of... https://www.jove.com/v/56137 557 21700 2017-11-06T17:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61806.jpg Behavioral Assessment of Visual Function via Optomotor Response and Cognitive Function via Y-Maze in Diabetic Rats Neural degeneration in both eyes and brain as a result of diabetes can be observed through behavioral tests carried out on rodents. The Y-maze, a measure of spatial cognition, and the optomotor response, a measure of visual function, both provide insight into potential diagnoses and... https://www.jove.com/v/61806 461 6000 2020-10-23T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63111.jpg Retinal Pathophysiological Evaluation in a Rat Model Diabetic retinopathy is one of the leading causes of blindness. Histology, blood-retinal barrier breakdown assay, and fluorescence angiography are valuable techniques to understand the pathophysiology of the retina, which could further enhance the efficient drug screening against diabetic... https://www.jove.com/v/63111 551 4700 2022-05-06T15:00:00+00:00 JoVE no https://visualize.jove.com/36374034-automated-real-time-pcr-detection-of-tickborne-diseases-using-the-panther-fusion-open-access-system monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40815/40815_article_thumb_40815.jpg Rapid Identification of Pathogens MALDI-TOF MS has transformed clinical microbiology by offering a rapid and reliable method for pathogen identification. The traditional approach to microbial identification typically involves time-consuming culture techniques and biochemical tests, which can delay the initiation of appropriate antimicrobial therapy. MALDI-TOF MS avoids these delays by using characteristic ribosomal protein mass patterns of microbial cells, enabling accurate species-level identification within minutes.Principle... https://www.jove.com/v/40815 85 2026-05-20T20:51:01+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40822/40822_article_thumb_40822.jpg Rocky Mountain Spotted Fever Rocky Mountain Spotted Fever (RMSF) is a severe tick-borne illness caused by Rickettsia rickettsii, a Gram-negative, coccobacillary bacterium. This pathogen is an obligate intracellular parasite, requiring a host cell for replication. Transmission occurs through the bite of an infected tick. In the United States, the most important vectors are Dermacentor variabilis (American dog tick) and Dermacentor andersoni (Rocky Mountain wood tick), though other tick species may also serve as vectors. https://www.jove.com/v/40822 86 2026-05-20T20:55:48+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54781.jpg High-throughput Detection of Respiratory Pathogens in Animal Specimens by Nanoscale PCR High-throughput testing of DNA and RNA based pathogens by nanoscale PCR is described using a syndromic canine and equine respiratory PCR... https://www.jove.com/v/54781 660 12000 2016-11-28T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56471.jpg Detecting the Lyme Disease Spirochete, Borrelia Burgdorferi, in Ticks Using Nested PCR Nested PCR is a sensitive, specific, and straightforward technique that can be applied to tick DNA extracts to probe for Borrelia burgdorferi, the causative agent of Lyme disease. The initial PCR experiment uses gene-specific primers to generate long amplicons, which then become templates for a subsequent reaction using internal primers. https://www.jove.com/v/56471 440 18200 2018-02-04T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57051.jpg Multiplexed Isothermal Amplification Based Diagnostic Platform to Detect Zika, Chikungunya, and Dengue 1 Current multiplexed diagnostics to detect Zika, chikungunya, and dengue viruses require complex sample preparation and expensive instrumentation, and are difficult to use in low resource environments. We show a diagnostic that uses isothermal amplification with target-specific strand displaceable probes to detect and differentiate these viruses with high sensitivity and... https://www.jove.com/v/57051 378 14400 2018-03-13T13:30:00+00:00 JoVE no https://visualize.jove.com/36493841-evaluation-of-huawei-smart-wearables-for-detection-of-atrial-fibrillation-in-patients-following-ischemic-stroke-the-liverpool-huawei-stroke-study monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13286.jpg Pulse rhythm Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding. Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle... https://www.jove.com/v/13286 90 JoVE no https://cloudfront.jove.com/files/ftp_upload/17887/17887_article_thumb_17887.jpg Holter Monitor: 24-Hour Monitoring Holter monitoring is a continuous electrocardiography (ECG) recording that tracks the heart's electrical activity over an extended period, generally 24 to 48 hours. This noninvasive diagnostic tool detects irregular heart rhythms that may not be captured during a standard ECG performed in a clinical setting.DeviceThe Holter monitor is a portable, small device connected to several electrodes on the patient's chest. These electrodes detect the heart's electrical signals and transmit them to the... https://www.jove.com/v/17887 83 2025-06-19T16:09:27+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17942/17942_article_thumb_17942.jpg Dysrhythmias V: Evaluating Dysrhythmias Dysrhythmias, also known as arrhythmias, are disturbances in the heart's rhythm that range from benign to life-threatening. A thorough evaluation is crucial for appropriate management and involves a comprehensive medical history, physical examination, and various diagnostic tests.Medical HistorySymptoms: Collect detailed information on palpitations, dizziness, syncope, chest pain, and fatigue. Note their onset, frequency, and triggers.Previous Cardiac Issues: Document any history of heart... https://www.jove.com/v/17942 90 2025-06-19T16:36:46+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58132.jpg Hydra, a Computer-Based Platform for Aiding Clinicians in Cardiovascular Analysis and Diagnosis This article presents a protocol based on Hydra — a web-based system for clinical decision support that integrates a full and detailed set of functionalities and services required by physicians for complete cardiovascular analysis, risk assessment, early diagnosis, treatment, and monitoring over time. https://www.jove.com/v/58132 471 2018-09-26T20:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60715.jpg Patient Directed Recording of a Bipolar Three-Lead Electrocardiogram using a Smartwatch with ECG Function We describe a protocol for the patient-directed registration of a three lead bipolar electrocardiogram by a smartwatch that functions identically to the Einthoven leads from standard electrocardiograms. This enables patients to record electrocardiograms on their own immediately after the onset of symptoms. https://www.jove.com/v/60715 303 2019-12-11T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67674.jpg Assessing the Accuracy of Fitness Smartwatch Data for Cardiovascular and Physical Activity Monitoring: A Validation Study in Digital Health Wearable technology has low cost and offers convenient monitoring of physiological data. However, the accuracy and reliability of these devices require cautious assessment to ensure their effectiveness and safety for users. This report describes the validation process of a commercial smartwatch in monitoring physiological data and physical activity. https://www.jove.com/v/67674 351 2025-02-21T21:40:00+00:00 JoVE no https://visualize.jove.com/36498651-artificial-intelligence-in-pediatric-cardiology-a-scoping-review monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1309.jpg Making MR Imaging Child's Play - Pediatric Neuroimaging Protocol, Guidelines and Procedure Despite an increase in the use of structural and functional magnetic resonance imaging (fMRI) in humans, the study of young pediatric populations remains a challenge. We present a hands-on, step-by-step video protocol including guidelines for clinicians and researchers intending to perform (f)MRI in young children. https://www.jove.com/v/1309 918 18300 2009-07-30T16:45:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12979.jpg Issues And Trends In Healthcare Delivery System The issues and trends in healthcare delivery are constantly changing. The COVID-19 pandemic is one recent issue that wreaked havoc on healthcare systems, causing a shortage of healthcare workers, high demand for medicines and supplies, and increased medical expenditure due to a lack of insurance. Other issues include rising healthcare costs and care fragmentation. Cost Containment Payment for healthcare services has historically promoted adoption of costly and often unnecessary or inefficient... https://www.jove.com/v/12979 89 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58132.jpg Hydra, a Computer-Based Platform for Aiding Clinicians in Cardiovascular Analysis and Diagnosis This article presents a protocol based on Hydra — a web-based system for clinical decision support that integrates a full and detailed set of functionalities and services required by physicians for complete cardiovascular analysis, risk assessment, early diagnosis, treatment, and monitoring over... https://www.jove.com/v/58132 471 7700 2018-09-26T13:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64931.jpg A Modified Sonographic Algorithm for Image Acquisition in Life-Threatening Emergencies in the Critically Ill Newborn Here, we present a protocol that can be applied in the neonatal intensive care unit and the delivery room in relation to three scenarios: cardiac arrest, hemodynamic deterioration, or respiratory decompensation. This protocol can be performed with a state-of-the-art ultrasound machine or an affordable handheld device; an image acquisition protocol is carefully... https://www.jove.com/v/64931 687 6400 2023-04-07T13:00:00+00:00 JoVE no https://visualize.jove.com/36553119-artificial-intelligence-ai-in-breast-imaging-a-scientometric-umbrella-review monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12979.jpg Issues And Trends In Healthcare Delivery System The issues and trends in healthcare delivery are constantly changing. The COVID-19 pandemic is one recent issue that wreaked havoc on healthcare systems, causing a shortage of healthcare workers, high demand for medicines and supplies, and increased medical expenditure due to a lack of insurance. Other issues include rising healthcare costs and care fragmentation. Cost Containment Payment for healthcare services has historically promoted adoption of costly and often unnecessary or inefficient... https://www.jove.com/v/12979 89 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66014.jpg Author Spotlight: Advancing CBCT and Digital Dental Image Integration with AI-Assisted Digitization A process of registering cone-beam computed tomography scans and digital dental images has been presented using artificial intelligence (AI) -assisted identification of landmarks and merging. A comparison with surface-based registration shows that AI-based digitization and integration are reliable and... https://www.jove.com/v/66014 349 937 2024-02-23T13:35:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68083.jpg Detection and Isolation of Cancer in Prostate Biopsies Using Stimulated Raman Histology and Artificial Intelligence Here, we present a standardized protocol for detecting prostate cancer using stimulated Raman histology (SRH) on biopsy samples due to advantages over traditional histopathology, focusing on sample preparation, imaging, and artificial intelligence to improve the cancer-to-tissue ratio. Additionally, it supports biobanking for transcriptomics, organoid or xenograft models, and identification of intraoperative surgical... https://www.jove.com/v/68083 488 145 2025-06-10T12:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68270.jpg Introduction of an Integrated Pathology Image Management, Artificial Intelligence, and Reporting System Integrated image management, artificial intelligence (AI), and reporting systems have revolutionized diagnostic pathology practice. In this paper, we introduce FlexLIS, a state-of-the-art system that enables AI to assist pathologists in performing histopathology image assessments and generating diagnostic reports. https://www.jove.com/v/68270 330 163 2025-07-11T15:40:00+00:00 JoVE no https://visualize.jove.com/36574922-machine-learning-approaches-for-electroencephalography-and-magnetoencephalography-analyses-in-autism-spectrum-disorder-a-systematic-review monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/19610.jpg Autism Spectrum Disorder Autism spectrum disorder (ASD) is a neurodevelopmental condition marked by persistent deficits in social communication and interaction alongside restrictive and repetitive behaviors or interests. ASD is sometimes accompanied by intellectual impairment. These core symptoms manifest differently among individuals, ranging from mild to severe. The disorder's complexity extends beyond its clinical presentation, encompassing a diverse range of biological, cognitive, and sociocultural influences.<br... https://www.jove.com/v/19610 79 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51412.jpg EEG Mu Rhythm in Typical and Atypical Development Assessment of the EEG mu rhythm provides a unique methodology for examining brain activity and when combined with behaviorally based assays, can be a powerful tool for elucidating aspects of social cognition, such as imitation, in clinical... https://www.jove.com/v/51412 710 25900 2014-04-09T22:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51705.jpg Cortical Source Analysis of High-Density EEG Recordings in Children In recent years, there has been increasing interest in estimating the cortical sources of scalp measured electrical activity for cognitive neuroscience experiments. This article describes how high density EEG is acquired and how recordings are processed for cortical source estimation in children from the age of 2 years at the London Baby... https://www.jove.com/v/51705 572 21400 2014-06-30T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53406.jpg A Novel Experimental and Analytical Approach to the Multimodal Neural Decoding of Intent During Social Interaction in Freely-behaving Human Infants This protocol presents a novel methodology for the neural decoding of intent from freely-behaving infants during unscripted social interaction with an actor. Neural activity is acquired using non-invasive high-density active scalp electroencephalography (EEG). Kinematic data is collected with inertial measurement units and supplemented with synchronized video recording. https://www.jove.com/v/53406 674 11000 2015-10-04T14:00:00+00:00 JoVE no https://visualize.jove.com/36577612-assessment-of-condition-induced-changes-on-the-ocular-surface-using-novel-methods-to-assess-the-tear-film-dynamics-and-the-lipid-layer monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17259/17259_article_thumb_17259.jpg Ophthalmic Drug Delivery Systems Ophthalmic drug delivery faces major limitations due to poor absorption across the corneal membrane. This process is primarily driven by diffusion and is influenced by two main factors: the physicochemical properties of the drug and tear drainage. Most ophthalmic drugs, such as pilocarpine, epinephrine, atropine, and local anesthetics, are weak bases. They are typically formulated at an acidic pH to enhance chemical stability. However, this leads to high ionization, reducing their ability to... https://www.jove.com/v/17259 83 2026-02-12T19:16:56+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40793/40793_article_thumb_40793.jpg Microbiome of the Eye The human eye has a specialized microbiota that reflects its unique anatomical and immunological environment. This low-biomass microbial community predominantly colonizes the conjunctiva and eyelid margins, playing a vital role in ocular surface homeostasis and defense. Despite its proximity to the richly colonized facial skin, the ocular surface maintains a distinct microbial profile due to continuous mechanical and biochemical defense mechanisms.The conjunctival surface hosts fewer microbial... https://www.jove.com/v/40793 82 2026-03-12T20:35:56+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53907.jpg Development of an In Vitro Ocular Platform to Test Contact Lenses Current in vitro models for evaluating contact lenses (CLs) and other eye-related applications are severely limited. The presented ocular platform simulates physiological tear flow, tear volume, air exposure and mechanical wear. This system is highly versatile and can be applied to various in vitro analyses with... https://www.jove.com/v/53907 508 10700 2016-04-06T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57811.jpg Intense Pulsed Light for the Treatment of Dry Eye Owing to Meibomian Gland Dysfunction Dry eye disease is an increasingly common condition, which strongly impair patients' life quality. Recently, a new device employing intense pulsed light, specifically designed for the periocular area, has been shown to improve tear film stability and ocular discomfort symptoms in dry eye disease owing to meibomian gland... https://www.jove.com/v/57811 300 15100 2019-04-01T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60812.jpg Effect of Artificial Tear Formulations on the Metabolic Activity of Human Corneal Epithelial Cells after Exposure to Desiccation The purpose of this protocol is to evaluate if different artificial tear formulations can protect human corneal epithelial cells from desiccation using an in vitro model. After exposure to artificial tear formulations and desiccation, human corneal epithelial cells are assessed for metabolic... https://www.jove.com/v/60812 389 3900 2020-05-02T13:00:00+00:00 JoVE no https://visualize.jove.com/36741250-real-time-smartphone-based-processing-of-lateral-flow-assays-for-early-failure-detection-and-rapid-testing-workflows monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40816/40816_article_thumb_40816.jpg Automated Microbial Diagnostics Automated diagnostic analyzers have transformed clinical microbiology by providing rapid and reliable methods for pathogen identification and antibiotic susceptibility testing. Among these systems, the Vitek 2 is widely used because it automates the traditionally labor-intensive processes of microbial identification (ID) and antibiotic susceptibility testing (AST), delivering standardized and timely results that are essential for effective patient care.Microbial Identification with ID CardsThe... https://www.jove.com/v/40816 84 2026-03-12T20:35:56+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56105.jpg Dry Film Photoresist-based Electrochemical Microfluidic Biosensor Platform: Device Fabrication, On-chip Assay Preparation, and System Operation A microfluidic biosensor platform was designed and fabricated using low-cost dry film photoresist technology for the rapid and sensitive quantification of various analytes. This single-use system allows for the electrochemical readout of on-chip-immobilized enzyme-linked assays by means of the stop-flow... https://www.jove.com/v/56105 822 11900 2017-09-19T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61406.jpg Low-Cost, Volume-Controlled Dipstick Urinalysis for Home-Testing Dipstick urinalysis is a quick and affordable method of assessing one’s personal state of health. We present a method to perform accurate, low-cost dipstick urinalysis that removes the primary sources of error associated with traditional dip-and-wipe protocols and is simple enough to be performed by lay users at... https://www.jove.com/v/61406 415 5600 2021-05-08T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66130.jpg Author Spotlight: Development of a Smartphone-Enhanced Paper-Based Device for Rapid Dengue NS1 Detection Addressing urgent dengue diagnostic needs, here we introduce a smartphone app-integrated Dengue NS1 Paper-based Analytical Device (DEN-NS1-PAD) for quantifying Dengue NS1 antigen concentration in clinical serum/blood samples. This innovation enhances dengue management by aiding clinical decision-making in various healthcare settings, even resource-limited ones. https://www.jove.com/v/66130 360 1500 2024-01-26T14:30:00+00:00 JoVE no https://visualize.jove.com/36801145-clinical-machine-learning-in-parafunctional-and-altered-functional-occlusion-a-systematic-review monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16410.jpg Assessment of the Mouth A thorough mouth assessment, including inspection and palpation of the lips, gums, tongue, tonsils, uvula, and pharynx, is crucial in detecting potential health issues. Diseases ranging from oral cancer to systemic conditions like diabetes could be identified early through careful oral examination. This article provides a detailed guide on conducting a comprehensive mouth assessment. Mouth Inspection The inspection begins with visually examining the mouth for symmetry, color, and size. https://www.jove.com/v/16410 86 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50336.jpg Use of the Operant Orofacial Pain Assessment Device OPAD to Measure Changes in Nociceptive Behavior We present a user-friendly, high-throughput operant system for the evaluation of pain behaviors in awake, conscious rodents. The Orofacial Pain Assessment Device (OPAD) can assess pain through a reward/conflict paradigm thus providing a more humane way of testing. This protocol will yield more clinically relevant and translational data from... https://www.jove.com/v/50336 740 21200 2013-06-10T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60363.jpg A Postoperative Evaluation Guideline for Computer-Assisted Reconstruction of the Mandible Here, we propose a practical, feasible and reproducible evaluation guideline for computer-assisted reconstruction of the mandible in order to create uniformity between studies regarding postoperative accuracy evaluation. This protocol continues and specifies an earlier publication of this evaluation... https://www.jove.com/v/60363 642 6600 2020-01-28T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65531.jpg Author Spotlight: 3D Movement Assessment of Maxillary Posterior Teeth in Clear Aligner Treatment This manuscript presents a comprehensive protocol to evaluate the three-dimensional (3D) movement of maxillary posterior teeth with clear aligners using digital model superimposition, an invaluable tool in orthodontics and dentofacial... https://www.jove.com/v/65531 452 1200 2024-02-23T14:25:00+00:00 JoVE no https://visualize.jove.com/37002296-a-clinical-decision-support-system-for-ai-assisted-decision-making-in-response-adaptive-radiotherapy-arclids monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3107.jpg Stem Cell Transplantation Strategies for the Restoration of Cognitive Dysfunction Caused by Cranial Radiotherapy Brain tumor patients routinely undergo cranial radiotherapy, and while beneficial, this treatment often results in debilitating cognitive dysfunction. This serious unresolved problem has at present, no clinical recourse, and has driven our efforts to devise stem cell based therapies for the recovery of radiation-induced cognitive... https://www.jove.com/v/3107 684 14700 2011-10-18T12:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14126.jpg Nursing Clinical Information System Nursing Clinical Information System (NCIS) A Nursing Clinical Information System (NCIS) is a specialized type of healthcare information system tailored to meet the unique needs of nursing practice. It incorporates the principles of nursing informatics to streamline information management and improve the quality of care delivery. Critical attributes of NCIS include: Efficient Information Management: NCIS is designed to manage patient information efficiently, making it easily accessible to... https://www.jove.com/v/14126 87 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57411.jpg Radiation Planning Assistant - A Streamlined, Fully Automated Radiotherapy Treatment Planning System Radiation therapy is a highly complex cancer treatment that requires multiple specialists to create a treatment plan and provide quality assurance (QA) prior to delivery to a patient. This protocol describes the use of a fully automated system, the Radiation Planning Assistant (RPA), to create high-quality radiation treatment... https://www.jove.com/v/57411 505 15400 2018-04-11T14:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65504.jpg Author Spotlight: Improving Radiation Therapy Access with Radiation Planning Assistant This protocol describes a series of automated tools designed for high-quality radiotherapy autocontouring and autoplanning that are being packaged into a web-based service to maximize robustness and scalability while minimizing operational... https://www.jove.com/v/65504 318 1400 2023-10-06T13:30:00+00:00 JoVE no https://visualize.jove.com/37322471-predicting-post-operative-vault-and-optimal-implantable-collamer-lens-size-using-machine-learning-based-on-various-ophthalmic-device-combinations monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14481.jpg Open Angle Glaucoma: Treatment In open-angle glaucoma, the iridocorneal angle remains open, but the trabecular meshwork becomes stiff, slowing down the outflow of aqueous humor. This causes a buildup of aqueous humor in the anterior chamber, leading to a sudden increase in intraocular pressure. The treatment for open-angle glaucoma focuses on reducing the elevated intraocular pressure by either decreasing the secretion of aqueous humor or increasing its outflow. Drugs such as carbonic anhydrase inhibitors, α2- and... https://www.jove.com/v/14481 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14482.jpg Angle Closure Glaucoma: Treatment Angle-closure glaucoma, or closed-angle glaucoma, is an eye condition where the iris bulges out and blocks the iridocorneal angle, resulting in a buildup of aqueous humor and increased intraocular pressure. Immediate medical attention is necessary due to the sudden onset of symptoms. The treatment for angle-closure glaucoma includes short-term and long-term approaches. Short-term treatment involves using eye drops like pilocarpine to lower intraocular pressure by increasing aqueous humor... https://www.jove.com/v/14482 88 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65419.jpg Author Spotlight: Enhancing Visual Outcomes in Cataract Surgery: A Novel Technique to Prevent Posterior Capsular Opacification Through IOL Rotation The present protocol describes removing residual epithelial cells by rotating the intraocular lens in extracapsular cataract surgery without extra tools for preventing posterior capsular... https://www.jove.com/v/65419 299 2400 2023-07-07T14:10:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66040.jpg Author Spotlight: Advancing Understanding of Age-Related Lens Stiffness Changes We present an automated method for characterizing the effective elastic modulus of an ocular lens using a compression... https://www.jove.com/v/66040 319 2400 2024-04-05T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66050.jpg Author Spotlight: Unraveling the Molecular Mechanisms in PCO and Fibrosis Following Cataract Surgery This method models cataract surgery in vivo by removing lens fiber cells from adult mice and leaving behind the capsular bag with attached lens epithelial cells (LECs). The injury response is then assessed at various times post-surgery using molecular and morphological criteria. https://www.jove.com/v/66050 319 1100 2023-12-01T14:25:00+00:00 JoVE no https://visualize.jove.com/37365814-using-occipital-bursts-to-modulate-behavior-in-real-time monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/2320.jpg Combining Computer Game-Based Behavioural Experiments With High-Density EEG and Infrared Gaze Tracking Procedures for recording high-density EEG and gaze data during computer game-based cognitive tasks are described. Using a video game to present cognitive tasks enhances ecological validity without sacrificing experimental... https://www.jove.com/v/2320 820 16800 2010-12-16T17:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16031.jpg Control Systems Control systems are everywhere in contemporary society, influencing diverse applications from aerospace to automated manufacturing. These systems can be found naturally within biological processes, such as blood sugar regulation and heart rate adjustment in response to stress, as well as in man-made systems like elevators and automated vehicles. A control system is essentially a network of subsystems and processes that collaboratively convert specific inputs into desired outputs. At the heart... https://www.jove.com/v/16031 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16093.jpg Effects of feedback Feedback in control systems plays a critical role in shaping various operational parameters, extending beyond simple error reduction to influence stability, bandwidth, gain, impedance, and sensitivity. Understanding these effects requires examining a basic feedback system characterized by defined input, output, error, and feedback signals. Feedback significantly modifies the gain of a control system. The gain of a system without feedback is altered by a factor of one plus GH, where G represents... https://www.jove.com/v/16093 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16094.jpg Feedback control systems Feedback control systems are categorized in various ways based on their design, analysis, and signal types. Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity... https://www.jove.com/v/16094 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16111.jpg Transient and Steady-state Response In control systems, test signals are essential for evaluating performance under various conditions. The ramp function is effective for systems undergoing gradual changes, while the step function is suitable for assessing systems facing sudden disturbances. For systems subjected to shock inputs, the impulse function is the most appropriate test signal. These test signals are integral in designing control systems to exhibit two key performance aspects: transient response and steady-state response. https://www.jove.com/v/16111 84 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16127.jpg Time-Domain Interpretation of PD Control Proportional-Derivative (PD) control is a widely used control method in various engineering systems to enhance stability and performance. In a system with only proportional control, common issues include high maximum overshoot and oscillation, observed in both the error signal and its rate of change. This behavior can be divided into three distinct phases: initial overshoot, subsequent undershoot, and gradual stabilization. Consider the example of control of motor torque. Initially, a positive... https://www.jove.com/v/16127 67 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17820.jpg Timing and Consequences on Behavior In operant conditioning, the timing of reinforcement is crucial. For animals like rats and cats, immediate reinforcement (within a few seconds) is much more effective than delayed reinforcement. For example, a food reward for a rat needs to follow within 30 seconds of pressing a bar to be effective. Humans, however, can respond to delayed reinforcers. We often make decisions between immediate small rewards and delayed larger rewards. This ability to delay gratification is a significant factor... https://www.jove.com/v/17820 68 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57349.jpg Optogenetic Entrainment of Hippocampal Theta Oscillations in Behaving Mice We describe the use of optogenetics and electrophysiological recordings for selective manipulations of hippocampal theta oscillations (5-10 Hz) in behaving mice. The efficacy of the rhythm entrainment is monitored using local field potential. A combination of opto- and pharmacogenetic inhibition addresses the efferent readout of hippocampal... https://www.jove.com/v/57349 453 11800 2018-06-29T13:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61023.jpg Optogenetic Manipulation of Neuronal Activity to Modulate Behavior in Freely Moving Mice With optogenetic manipulation of specific neuronal populations or brain regions, behavior can be modified with high temporal and spatial resolution in freely moving animals. By using different optogenetic tools in combination with chronically implanted optical fibers, a variety of neuronal modulations and behavioral testing can be... https://www.jove.com/v/61023 880 18400 2020-10-27T12:30:00+00:00 JoVE no https://visualize.jove.com/37485358-a-hybrid-physics-based-and-data-driven-framework-for-cellular-biological-systems-application-to-the-morphogenesis-of-organoids monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12157.jpg Non-equilibrium in the Cell An important concept in studying metabolism and energy is that of chemical equilibrium. Most chemical reactions are reversible. They can proceed in both directions, releasing energy into their environment in one direction, and absorbing it from the environment in the other direction. The same is true for the chemical reactions involved in cell metabolism, such as the breaking down and building up of proteins into and from individual amino acids, respectively. Reactants within a closed system... https://www.jove.com/v/12157 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16585.jpg Mechanistic Models: Compartment Models in Individual and Population Analysis Mechanistic models are utilized in individual analysis using single-source data, but imperfections arise due to data collection errors, preventing perfect prediction of observed data. The mathematical equation involves known values (Xi), observed concentrations (Ci), measurement errors (εi), model parameters (ϕj), and the related function (ƒi) for i number of values. Different least-squares metrics quantify differences between predicted and observed values. The ordinary least squares (OLS)... https://www.jove.com/v/16585 83 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16587.jpg Model Approaches for Pharmacokinetic Data: Physiological Models Physiological models in pharmacokinetics are instrumental in understanding the distribution and elimination of drugs within the body. These models describe the drug concentration within target organs, influenced by factors such as drug uptake, tissue volume, and blood flow. Drug uptake is governed by the partition coefficient, which signifies the drug concentration ratio in tissue to that in the blood. The blood flow rate to a specific tissue is expressed as Qt, and the rate of change in tissue... https://www.jove.com/v/16587 75 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53606.jpg Bioprinting Cellularized Constructs Using a Tissue-specific Hydrogel Bioink We describe a set of protocols that together provide a tissue-mimicking hydrogel bioink with which functional and viable 3-D tissue constructs can be bioprinted for use in in vitro screening... https://www.jove.com/v/53606 514 16800 2016-04-21T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59226.jpg 3D Analysis of Multi-cellular Responses to Chemoattractant Gradients We describe a method to construct devices for 3D culture and experimentation with cells and multicellular organoids. This device allows analysis of cellular responses to soluble signals in 3D microenvironments with defined chemoattractant gradients. Organoids are better than single cells at detection of weak noisy... https://www.jove.com/v/59226 357 6600 2019-05-24T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64405.jpg A High-Throughput Platform for Culture and 3D Imaging of Organoids This paper presents a fabrication protocol for a new type of culture substrate with hundreds of microcontainers per mm2, in which organoids can be cultured and observed using high-resolution microscopy. The cell seeding and immunostaining protocols are also... https://www.jove.com/v/64405 462 2800 2022-10-14T14:00:00+00:00 JoVE no https://visualize.jove.com/37499249-chimera-states-in-a-large-laterally-coupled-laser-array-with-four-different-waveguide-structures monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14589.jpg Mass Spectrum: Interpretation An unknown compound can be established by identifying the molecular ion peak in the mass spectrum. The molecular ion peak is often weak or absent due to the predominance of fragmentation in high-energy electron beams. In such cases, a soft-energy electron beam can be used to scan the spectrum to enhance the intensity of the molecular ion peak. Additionally, chemical ionization, field ionization, and desorption ionization spectra are used to obtain a relatively intense molecular ion peak.To... https://www.jove.com/v/14589 84 2025-12-12T20:31:50+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50216.jpg Fabrication And Characterization Of Photonic Crystal Slow Light Waveguides And Cavities Use of photonic crystal slow light waveguides and cavities has been widely adopted by the photonics community in many differing applications. Therefore fabrication and characterization of these devices are of great interest. This paper outlines our fabrication technique and two optical characterization methods, namely: interferometric (waveguides) and resonant scattering... https://www.jove.com/v/50216 668 19000 2012-11-30T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55257.jpg Measurement of Quantum Interference in a Silicon Ring Resonator Photon Source Silicon photonic chips have the potential to realize complex integrated quantum systems. Presented here is a method for preparing and testing a silicon photonic chip for quantum... https://www.jove.com/v/55257 739 8500 2017-04-04T10:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59158.jpg Shaping the Amplitude and Phase of Laser Beams by Using a Phase-only Spatial Light Modulator We show how to encode the complex field of laser beams by using a single phase element. A common-path interferometer is employed to mix the phase information displayed into a phase-only spatial light modulator to finally retrieve the desired complex field pattern at the output of an optical imaging... https://www.jove.com/v/59158 519 9900 2019-01-28T15:00:00+00:00 JoVE no https://visualize.jove.com/37510207-the-predictive-capabilities-of-artificial-intelligence-based-oct-analysis-for-age-related-macular-degeneration-progression-a-systematic-review monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13483.jpg iPS Cell Differentiation The ability of induced pluripotent stem cells or iPSCs to differentiate into most body cell types has stimulated repair and regenerative medicine research over the past few decades. iPSC-derived blood cells, hepatocytes, beta islet cells, cardiomyocytes, neurons, and other cell types can repair injuries or regenerate damaged tissue in diseases such as diabetes and neurodegenerative disorders. iPSCs have been successfully used to treat age-related macular degeneration (AMD), a form of blindness. https://www.jove.com/v/13483 82 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65238.jpg Author Spotlight: Understanding Age-Related Macular Degeneration Pathophysiology with QAF Workflow This research describes a workflow to determine and compare autofluorescence levels from individual regions of interest (e.g., drusen and subretinal drusenoid deposits in age-related macular degeneration [AMD]) while accounting for varying autofluorescence levels throughout the... https://www.jove.com/v/65238 534 1500 2023-05-26T12:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65240.jpg Author Spotlight: Ex Vivo OCT-Based Multimodal Imaging of Human Donor Eyes for Research into Age-Related Macular Degeneration Laboratory assays can leverage prognostic value from the longitudinal optical coherence tomography (OCT)-based multimodal imaging of age-related macular degeneration (AMD). Human donor eyes with and without AMD are imaged using OCT, color, near-infrared reflectance scanning laser ophthalmoscopy, and autofluorescence at two excitation wavelengths prior to tissue... https://www.jove.com/v/65240 614 3300 2023-05-26T14:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65503.jpg Author Spotlight: Unraveling the Pathogenesis of Age-Related Macular Degeneration and Discovering Potential Therapies Degenerative eye diseases that affect the retinal pigment epithelium layer of the eye have monogenic and polygenic origins. Several disease models and a software application, LipidUNet, have been developed to study mechanisms of disease, as well as potential therapeutic... https://www.jove.com/v/65503 376 2600 2023-07-28T12:50:00+00:00 JoVE no https://visualize.jove.com/37510528-evaluation-of-atlas-based-mobile-application-in-undergraduate-teaching-in-oral-histopathology monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16410.jpg Assessment of the Mouth A thorough mouth assessment, including inspection and palpation of the lips, gums, tongue, tonsils, uvula, and pharynx, is crucial in detecting potential health issues. Diseases ranging from oral cancer to systemic conditions like diabetes could be identified early through careful oral examination. This article provides a detailed guide on conducting a comprehensive mouth assessment. Mouth Inspection The inspection begins with visually examining the mouth for symmetry, color, and size. https://www.jove.com/v/16410 86 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51325.jpg Reconstruction of 3-Dimensional Histology Volume and its Application to Study Mouse Mammary Glands We present an image registration approach for 3-dimensional (3D) histology volume reconstruction, which facilitates the study of the changes of an organ at the level of macrostructures made up of cells . Using this approach, we studied the 3D changes between wild-type and Igfbp7-null mammary glands. https://www.jove.com/v/51325 659 14500 2014-07-26T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56246.jpg Exploring Deep Space - Uncovering the Anatomy of Periventricular Structures to Reveal the Lateral Ventricles of the Human Brain This paper demonstrates the effective use of a fiber dissection method to reveal the superficial white matter tracts and periventricular structures of the human brain, in three-dimensional space, to aid student comprehension of ventricular... https://www.jove.com/v/56246 1033 16800 2017-10-22T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66253.jpg Author Spotlight: 3D Scanning and Augmented Reality for Enhanced Cancer Surgery Communication A novel method for 3D scanning and virtual mapping of cancer resections is proposed with the goal of improving communication among the multidisciplinary cancer care team. https://www.jove.com/v/66253 467 740 2023-12-15T14:55:00+00:00 JoVE no https://visualize.jove.com/37549398-dynamic-fusion-of-nucleic-acid-functionalized-nano-micro-cell-like-containments-from-basic-concepts-to-applications monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1432.jpg Combining QD-FRET and Microfluidics to Monitor DNA Nanocomplex Self-Assembly in Real-Time We present a novel and powerful integration of nanophotonics (QD-FRET) and microfluidics to investigate the formation of polyelectrolyte polyplexes, which is expected to provide better control and synthesis of uniform and customizable polyplexes for future nucleic acid-based... https://www.jove.com/v/1432 876 11200 2009-08-26T16:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13559.jpg Methods of Nuclear Reprogramming Nuclear reprogramming is a process of transforming one cell type into an unrelated cell type by epigenetic changes that alter the cell’s original gene expression pattern. Such epigenetic changes force cells to express a different set of genes, which play a significant role in inducing transformation into other cell types. Nuclear reprogramming offers applications in reproductive cloning for livestock propagation and regenerative medicine — developing patient-specific cells for injury repair.<br... https://www.jove.com/v/13559 84 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51272.jpg Folding and Characterization of a Bio-responsive Robot from DNA Origami DNA origami is a powerful method for fabricating precise nanoscale objects by programming the self-assembly of DNA molecules. Here we describe a protocol for the folding of a bio-responsive robot from DNA origami, its purification and negative staining for transmission electron microscopic imaging (TEM). https://www.jove.com/v/51272 479 14600 2015-12-03T10:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66738.jpg Author Spotlight: Developing Synthetic Cells from Programmable Amphiphilic DNA Nanostructures We present a protocol for preparing synthetic biomolecular condensates consisting of amphiphilic DNA nanostars starting from their constituent DNA oligonucleotides. Condensates are produced from either a single nanostar component or two components and are modified to sustain in vitro transcription of RNA from an embedded DNA template. https://www.jove.com/v/66738 482 809 2024-05-31T14:15:00+00:00 JoVE no https://visualize.jove.com/37592148-a-novel-artificial-intelligence-model-for-symmetry-evaluation-in-breast-cancer-patients monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12079.jpg Adaptive Mechanisms in Cancer Cells Cancer cells accumulate genetic changes at an abnormally rapid rate due to the defects in the DNA repair mechanisms. From an evolutionary perspective, such genetic instability is advantageous for cancer development. Mutant cell lines accumulate a series of beneficial mutations that contribute to their progression into cancer. Some of the advantages that cancer cells have on normal cells include - enhanced ability to divide without terminally differentiating, induce new blood vessel formation,... https://www.jove.com/v/12079 173 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12079.jpg Adaptive Mechanisms in Cancer Cells Cancer cells accumulate genetic changes at an abnormally rapid rate due to the defects in the DNA repair mechanisms. From an evolutionary perspective, such genetic instability is advantageous for cancer development. Mutant cell lines accumulate a series of beneficial mutations that contribute to their progression into cancer. Some of the advantages that cancer cells have on normal cells include - enhanced ability to divide without terminally differentiating, induce new blood vessel formation,... https://www.jove.com/v/13443 173 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50341.jpg Detection of Architectural Distortion in Prior Mammograms via Analysis of Oriented Patterns We demonstrate methods for the detection of architectural distortion in prior mammograms. Oriented structures are analyzed using Gabor filters and phase portraits to detect sites of radiating tissue patterns. Each site is characterized and classified using measures to represent spiculating patterns. The methods should assist in the detection of breast... https://www.jove.com/v/50341 824 42900 2013-08-30T12:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61805.jpg Using Computer-based Image Analysis to Improve Quantification of Lung Metastasis in the 4T1 Breast Cancer Model We describe a more consistent and expeditious method to quantify lung metastasis in the 4T1 breast cancer model by using... https://www.jove.com/v/61805 512 6300 2020-10-02T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62009.jpg Modeling Breast Cancer in Human Breast Tissue using a Microphysiological System This protocol describes the construction of an in vitro microphysiological system for studying breast cancer using primary human breast tissue with off the shelf... https://www.jove.com/v/62009 651 4200 2021-04-23T14:00:00+00:00 JoVE no https://visualize.jove.com/37605875-artificial-intelligence-accelerated-high-throughput-screening-of-antibiotic-combinations-on-a-microfluidic-combinatorial-droplet-system monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40816/40816_article_thumb_40816.jpg Automated Microbial Diagnostics Automated diagnostic analyzers have transformed clinical microbiology by providing rapid and reliable methods for pathogen identification and antibiotic susceptibility testing. Among these systems, the Vitek 2 is widely used because it automates the traditionally labor-intensive processes of microbial identification (ID) and antibiotic susceptibility testing (AST), delivering standardized and timely results that are essential for effective patient care.Microbial Identification with ID CardsThe... https://www.jove.com/v/40816 84 2026-03-12T13:35:56+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50828.jpg Stress-induced Antibiotic Susceptibility Testing on a Chip We have developed a microfluidic platform for rapid antibiotic susceptibility testing. Fluid is passed at high speeds over bacteria immobilized on the bottom of a microfluidic channel. In the presence of stress and antibiotic, susceptible strains of bacteria die rapidly. However, resistant bacteria can survive these stressful... https://www.jove.com/v/50828 761 6500 2014-01-08T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58636.jpg Antimicrobial Synergy Testing by the Inkjet Printer-assisted Automated Checkerboard Array and the Manual Time-kill Method Antimicrobial synergy testing is used to evaluate the effect of two or more antibiotics used in combination and is typically performed by one of two methods: the checkerboard array or the time-kill assay. Here, we present an automated, inkjet printer-assisted checkerboard array synergy technique and a classic time-kill synergy... https://www.jove.com/v/58636 723 26300 2019-04-18T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66154.jpg Author Spotlight: Integrating Computational and Experimental Approaches in Precision Oncology The fabrication of a polydimethylsiloxane (PDMS)-based bilayer device for the production of combinatorial libraries in water-in-oil emulsions (plugs) is presented here. The necessary hardware and software required to automate plug production are detailed in the protocol, and the production of a quantitative library of fluorescent plugs is also demonstrated. https://www.jove.com/v/66154 423 946 2023-12-01T12:30:00+00:00 JoVE no https://visualize.jove.com/37638964-a-systematic-literature-review-of-accessibility-evaluation-methods-for-augmented-reality-applications monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17149/17149_article_thumb_17149.jpg Bioavailability Enhancement: Determination and Conceptual Approaches in Overcoming Bioavailability Problems Bioavailability is a critical pharmacological concept that measures the extent and rate at which an active drug ingredient or therapeutic moiety enters the systemic circulation, remaining unchanged. It's a pivotal factor in determining a drug's efficacy and safety.The Biopharmaceutics Classification System (BCS) plays an essential role in drug development by categorizing drugs into four classes based on their solubility and permeability. This classification aids in understanding drug absorption... https://www.jove.com/v/17149 82 2026-03-02T20:14:30+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50272.jpg Development of an Audio-based Virtual Gaming Environment to Assist with Navigation Skills in the Blind Audio-based Environment Simulator (AbES) is virtual environment software designed to improve real world navigation skills in the... https://www.jove.com/v/50272 541 14400 2013-03-27T08:55:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61349.jpg Evaluating Usability Aspects of a Mixed Reality Solution for Immersive Analytics in Industry 4.0 Scenarios This protocol delineates the technical setting of a developed mixed reality application that is used for immersive analytics. Based on this, measures are presented, which were used in a study to gain insights into usability aspects of the developed technical... https://www.jove.com/v/61349 362 2300 2020-10-06T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64667.jpg Usability Evaluation of Augmented Reality: A Neuro-Information-Systems Study This study presents an experimental paradigm for a usability test combining subjective and objective evaluations. The objective evaluation adopted Neuro-Information-Systems (NeuroIS) methods, and the subjective evaluation adopted a usability questionnaire and a NASA-Task Load Index (NASA-TLX)... https://www.jove.com/v/64667 343 2400 2022-11-30T14:40:00+00:00 JoVE no https://visualize.jove.com/37682418-evaluation-of-an-artificial-intelligence-based-system-for-echocardiographic-estimation-of-right-atrial-pressure monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17881.jpg Imaging Studies for Cardiovascular System I:Echocardiography Cardiac imaging studies encompass a wide range of noninvasive and minimally invasive techniques designed to visualize the heart's structure and function in detail. One such technique is echocardiography, which uses high-frequency ultrasound waves to produce detailed images of the heart, known as echocardiograms. Indications: Echocardiography is utilized to diagnose heart failure, valve disorders, and myocardial infarction. It also assesses cardiac structures' size, shape, and motion, evaluates... https://www.jove.com/v/17881 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17882.jpg Imaging Studies for Cardiovascular System II:Types of Echocardiography Echocardiography plays a role in assessing cardiac health and detecting heart conditions, with various types providing critical insights for diagnosis and treatment. Types of Echocardiography Transthoracic Echocardiography (TTE) TTE is the most common type of echocardiogram which involves placing a transducer on the patient's chest, emitting sound waves to create heart images. TTE is invaluable for evaluating the heart's size, structure, and motion, making it particularly useful for diagnosing... https://www.jove.com/v/17882 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50912.jpg Echocardiographic Assessment of the Right Heart in Mice This article provides a protocol for the echocardiographic assessment of right ventricular size and pulmonary hypertension in mice. Applications include phenotype determination and serial assessment in transgenic and toxin-induced mouse models of cardiomyopathy and pulmonary vascular... https://www.jove.com/v/50912 569 23000 2013-11-27T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55214.jpg Murine Echocardiography of Left Atrium, Aorta, and Pulmonary Artery The following protocol describes the methodology for the acquisition and analysis of echocardiographic images used to obtain the Left Atrial Volume (LAV), Aorta (Ao) diameter, and Pulmonary Artery (PA) diameter in mice. This technique is a non-invasive, non-terminal procedure that allows assessment of the cardiopulmonary... https://www.jove.com/v/55214 497 14400 2017-02-20T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65353.jpg Author Spotlight: Advancements in Intracardiac Echocardiography for Atrial Anatomy Assessment Accurate intracardiac echocardiography (ICE) shows significant accuracy in estimating the left atrial structure, a prospective and promising cardiac structure estimation method. Here we propose a protocol for three-dimensional modeling of the left atrium and pulmonary veins with ICE and fast anatomical mapping (FAM) catheter... https://www.jove.com/v/65353 269 940 2023-06-30T13:20:00+00:00 JoVE no https://visualize.jove.com/37706480-content-and-quality-of-mobile-apps-for-the-monitoring-of-musculoskeletal-or-neuropathic-pain-in-australia-systematic-evaluation monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15185.jpg Analgesia and Pain Management Pain is critical to various clinical pathologies, provoking an urgent need for effective management. Pain, whether acute or chronic, is a complex neurochemical process. Its alleviation depends on the type, with nonopioid analgesics effective for mild to moderate pain, such as musculoskeletal or inflammatory pain, while neuropathic pain responds best to anticonvulsants, tricyclic antidepressants, or serotonin/norepinephrine reuptake inhibitors. For severe acute or chronic pain, opioids may be... https://www.jove.com/v/15185 85 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54659.jpg Video Movement Analysis Using Smartphones ViMAS: A Pilot Study This manuscript describes the method to test the concurrent validity of kinematic measures recorded by the smartphone application in comparison to a 3D motion capture system in the sagittal plane. This protocol will enable clinicians to set up smartphones for video capture of human... https://www.jove.com/v/54659 471 16900 2017-03-14T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59057.jpg Multi-Modal Signals for Analyzing Pain Responses to Thermal and Electrical Stimuli This article focuses on the experimental elicitation of pain through heat (thermal) and electrical stimulation while recording physiological, visual, and paralinguistic responses. It aims at collecting valid multimodal data for analyzing pain based on its intensity, quality, and... https://www.jove.com/v/59057 556 10800 2019-04-05T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67006.jpg Biomechanical Changes Related to Low Back Pain: An Innovative Tool for Movement Pattern Assessment and Treatment Evaluation in Rehabilitation This study shows the role of an innovative tool for assessing and treating biomechanical alterations in low back pain (LBP) patients. Three LBP patients demonstrated improved pain intensity and functional independence post-assessment. The technology aids in tailored rehabilitation strategies, offering insights into LBP biomechanics for personalized... https://www.jove.com/v/67006 388 556 2024-12-13T12:20:00+00:00 JoVE no https://visualize.jove.com/37708002-how-to-evaluate-if-collaborative-augmented-reality-speaks-to-its-users monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11040.jpg Self-Evaluation: Self-Enhancement and Self-Verification Social psychologists have documented that feeling good about ourselves and maintaining positive self-esteem is a powerful motivator of human behavior (Tavris & Aronson, 2008). In the United States, members of the predominant culture typically think very highly of themselves and view themselves as good people who are above average on many desirable traits (Ehrlinger, Gilovich, & Ross, 2005). Often, our behavior, attitudes, and beliefs are affected when we experience a threat to our... https://www.jove.com/v/11040 180 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11079.jpg Social Facilitation Not all intergroup interactions lead to negative outcomes. Sometimes, being in a group situation can improve performance. Social facilitation occurs when an individual performs better when an audience is watching than when the individual performs the behavior alone. This typically occurs when people are performing a task for which they are skilled. Can you think of an example in which having an audience could improve performance? One common example is sports. Skilled basketball players will be... https://www.jove.com/v/11079 64 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13506.jpg Communication Sharing information, concepts, and emotions to foster mutual understanding is communication. The sender, recipient, and transaction must be considered in this manner. The sender is the person who shares the message, the recipient is the person who receives and understands the message, and the transaction is the method used to deliver the message and the variables that affect the communication's context and surroundings. The nurse-client connection is built on therapeutic communication. Within... https://www.jove.com/v/13506 88 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13508.jpg Levels of Communication II: Organizational, Public, and Group Dynamics Effective communication is the foundation of a good organization. Communication is the lifeblood of an organization that connects the group with messages. In an organization, communication occurs in upward, downward, and horizontal lines. Downward communication travels from the administrative and senior levels to the staff through official channels such as manuals, rules and regulations, and organizational charts. Staff members initiate upward communication, which is addressed to executives and... https://www.jove.com/v/13508 87 JoVE no https://cloudfront.jove.com/files/ftp_upload/19887/19887_article_thumb_19887.jpg Self-Evaluation Maintenance Model The Self-Evaluation Maintenance (SEM) model offers a psychological framework to understand how individuals’ self-esteem is influenced by the achievements of others, particularly those with whom they share close personal bonds. The SEM model operates when personal rather than social identity guides individuals. Central to this model is the notion that individuals have an inherent desire to preserve a favorable self-image, which is continuously shaped by interpersonal comparisons and... https://www.jove.com/v/19887 89 2025-09-18T10:24:22+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19897/19897_article_thumb_19897.jpg Impression Management Techniques III: Aligning Actions Aligning actions are communicative strategies individuals employ to maintain social harmony and preserve personal identity in the face of potential disruptions to social norms. These actions are particularly important in managing social impressions when one's behavior might be seen as inappropriate, incompetent, or morally questionable.Types of Aligning ActionsThe three principal types of aligning actions are disclaimers, accounts, and apologies.DisclaimersDisclaimers are preventive; they are... https://www.jove.com/v/19897 89 2025-09-18T10:24:13+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60670.jpg A Methodology for Capturing Joint Visual Attention Using Mobile Eye-Trackers Using multimodal sensors is a promising way to understand the role of social interactions in educational settings. This paper describes a methodology for capturing joint visual attention from colocated dyads using mobile... https://www.jove.com/v/60670 759 7700 2020-01-18T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61349.jpg Evaluating Usability Aspects of a Mixed Reality Solution for Immersive Analytics in Industry 4.0 Scenarios This protocol delineates the technical setting of a developed mixed reality application that is used for immersive analytics. Based on this, measures are presented, which were used in a study to gain insights into usability aspects of the developed technical... https://www.jove.com/v/61349 362 2300 2020-10-06T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64667.jpg Usability Evaluation of Augmented Reality: A Neuro-Information-Systems Study This study presents an experimental paradigm for a usability test combining subjective and objective evaluations. The objective evaluation adopted Neuro-Information-Systems (NeuroIS) methods, and the subjective evaluation adopted a usability questionnaire and a NASA-Task Load Index (NASA-TLX)... https://www.jove.com/v/64667 343 2400 2022-11-30T14:40:00+00:00 JoVE no https://visualize.jove.com/37719872-identifying-alzheimers-disease-and-mild-cognitive-impairment-with-atlas-based-multi-modal-metrics monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40948/40948_article_thumb_40948.jpg Dementia l: Introduction Dementia is an acquired, progressive syndrome characterized by a decline in multiple cognitive domains severe enough to impair daily functioning and reduce independence. Although memory loss is a central feature, the diagnosis requires additional deficits involving language, executive function, visuospatial skills, judgment, calculation, or abstract reasoning. These cognitive impairments reflect underlying neurodegenerative or vascular processes that gradually disrupt neuronal networks... https://www.jove.com/v/40948 82 2026-04-13T22:55:59+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50887.jpg Lesion Explorer: A Video-guided, Standardized Protocol for Accurate and Reliable MRI-derived Volumetrics in Alzheimer's Disease and Normal Elderly Lesion Explorer (LE) is a semi-automatic, image-processing pipeline developed to obtain regional brain tissue and subcortical hyperintensity lesion volumetrics from structural MRI of Alzheimer's disease and normal elderly. To ensure a high level of accuracy and reliability, the following is a video-guided, standardized protocol for LE's manual... https://www.jove.com/v/50887 770 40300 2014-04-14T16:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54454.jpg The 4 Mountains Test: A Short Test of Spatial Memory with High Sensitivity for the Diagnosis of Pre-dementia Alzheimer's Disease This article describes the 4 Mountains Test (4MT), a hippocampus-dependent test of working allocentric spatial memory. The hippocampus is affected early in Alzheimer's disease (AD) and this article outlines the 4MT methodology and results of patient testing, which demonstrates the value of the 4MT in the diagnosis of pre-dementia AD. https://www.jove.com/v/54454 383 32400 2016-10-13T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57256.jpg Whole-brain Segmentation and Change-point Analysis of Anatomical Brain MRI—Application in Premanifest Huntington's Disease This paper describes a statistical model for volumetric MRI data analysis, which identifies the "change-point" when brain atrophy begins in premanifest Huntington's disease. Whole-brain mapping of the change-points is achieved based on brain volumes obtained using an atlas-based segmentation pipeline of T1-weighted... https://www.jove.com/v/57256 546 12200 2018-06-09T13:00:00+00:00 JoVE no https://visualize.jove.com/37724285-guidelines-on-clinical-research-evaluation-of-artificial-intelligence-in-ophthalmology-2023 monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12979.jpg Issues And Trends In Healthcare Delivery System The issues and trends in healthcare delivery are constantly changing. The COVID-19 pandemic is one recent issue that wreaked havoc on healthcare systems, causing a shortage of healthcare workers, high demand for medicines and supplies, and increased medical expenditure due to a lack of insurance. Other issues include rising healthcare costs and care fragmentation. Cost Containment Payment for healthcare services has historically promoted adoption of costly and often unnecessary or inefficient... https://www.jove.com/v/12979 89 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51205.jpg A Standardized Obstacle Course for Assessment of Visual Function in Ultra Low Vision and Artificial Vision We describe an indoor, portable, standardized course that can be used to evaluate obstacle avoidance in persons who have ultralow vision. The course is relatively inexpensive, simple to administer, and has been shown to be reliable and... https://www.jove.com/v/51205 569 13100 2014-02-11T16:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62521.jpg Artificial Intelligence Approaches to Assessing Primary Cilia The use of artificial intelligence (Ai) to analyze images is emerging as a powerful, less biased, and rapid approach compared with commonly used methods. Here we trained Ai to recognize a cellular organelle, primary cilia, and analyze properties such as length and staining intensity in a rigorous and reproducible manner. https://www.jove.com/v/62521 538 3500 2021-05-01T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66014.jpg Author Spotlight: Advancing CBCT and Digital Dental Image Integration with AI-Assisted Digitization A process of registering cone-beam computed tomography scans and digital dental images has been presented using artificial intelligence (AI) -assisted identification of landmarks and merging. A comparison with surface-based registration shows that AI-based digitization and integration are reliable and... https://www.jove.com/v/66014 349 879 2024-02-23T13:35:00+00:00 JoVE no https://visualize.jove.com/37863860-editors-statement-on-the-responsible-use-of-generative-ai-technologies-in-scholarly-journal-publishing monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10771.jpg Genetic Lingo Overview An organism is diploid if it inherits two variants, or alleles, of each gene, one from each parent. These two alleles constitute the genotype for a given gene. The term genotype is also used to refer to an organism’s complete set of genes. A diploid organism with two identical alleles has a homozygous genotype, whereas two different alleles indicates a heterozygous genotype. Observable traits arising from genotypes are called phenotypes, which can also be influenced by environmental... https://www.jove.com/v/10771 71 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10797.jpg What is Gene Expression? Overview Gene expression is the process in which DNA directs the synthesis of functional products, that is, proteins. Cells can regulate gene expression at various stages. It allows organisms to generate different cell types and enables cells to adapt to internal and external factors. Genetic Information Flows from DNA to RNA to Protein A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is made up of nucleotides and proteins consist of amino... https://www.jove.com/v/10797 102 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10806.jpg What is Genetic Engineering? Overview Genetic engineering is the process of modifying an organism’s DNA to introduce new, desirable traits. Many organisms, from bacteria to plants and animals, have been genetically modified for academic, medical, agricultural, and industrial purposes. While genetic engineering has definite benefits, ethical concerns surround modifying humans and our food supply. Scientists can Deliberately Modify an Organism’s Genome Genetic engineering is possible because the genetic code—the way... https://www.jove.com/v/10806 49 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10815.jpg Gene Therapy Gene therapy is a technique where a gene is inserted into a person’s cells to prevent or treat a serious disease. The added gene may be a healthy version of the gene that is mutated in the patient, or it could be a different gene that inactivates or compensates for the patient’s disease-causing gene. For example, in patients with severe combined immunodeficiency (SCID) due to a mutation in the gene for the enzyme adenosine deaminase, a functioning version of the gene can be inserted. The... https://www.jove.com/v/10815 59 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12157.jpg Non-equilibrium in the Cell An important concept in studying metabolism and energy is that of chemical equilibrium. Most chemical reactions are reversible. They can proceed in both directions, releasing energy into their environment in one direction, and absorbing it from the environment in the other direction. The same is true for the chemical reactions involved in cell metabolism, such as the breaking down and building up of proteins into and from individual amino acids, respectively. Reactants within a closed system... https://www.jove.com/v/12157 76 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12555.jpg What is Gene Expression? A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is comprised of nucleotides and proteins are comprised of amino acids, a mediator is required to convert the information encoded in DNA into proteins. This mediator is the messenger RNA (mRNA). mRNA copies the blueprint from DNA by a process called transcription. In eukaryotes, transcription occurs in the nucleus by complementary base-pairing with the DNA template. The mRNA is then processed and... https://www.jove.com/v/12555 96 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65073.jpg Using Generative Art to Convey Past and Future Climate Transitions Here, a protocol is presented to visualize climate data as generative art. https://www.jove.com/v/65073 370 993 2023-03-31T13:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66796.jpg Augmenting Large Language Models via Vector Embeddings to Improve Domain-Specific Responsiveness In this protocol, foundation large language model response quality is improved via augmentation with peer-reviewed, domain-specific scientific articles through a vector embedding mechanism. Additionally, code is provided to aid in performance comparison across large language... https://www.jove.com/v/66796 194 599 2024-12-06T12:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67525.jpg Evidence-based Knowledge Synthesis and Hypothesis Validation: Navigating Biomedical Knowledge Bases via Explainable AI and Agentic Systems This article describes RUGGED (Retrieval Under Graph-Guided Explainable disease Distinction), which integrates Large Language Model (LLM) inference with Retrieval-Augmented Generation (RAG). It draws evidence from expert-curated biomedical knowledge bases and peer-reviewed biomedical publications to synthesize new knowledge from up-to-date information, identify explainable and actionable predictions, and pinpoint promising directions for hypothesis-driven... https://www.jove.com/v/67525 347 250 2025-06-13T13:10:00+00:00 JoVE no https://visualize.jove.com/37864888-before-after-safety-evaluation-of-part-time-protected-right-turn-signals-an-extreme-value-theory-approach-by-applying-artificial-intelligence-based-video-analytics monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/19923/19923_article_thumb_19923.jpg Automatic Processing and Automatic Social Behavior Automatic processing refers to the cognitive operations that occur without conscious intent or awareness, playing a fundamental role in shaping social cognition and behavior. These processes enable individuals to navigate complex social environments efficiently by relying on mental shortcuts and pre-existing knowledge structures known as schemas. One of the most influential mechanisms underlying automatic processing is priming, which subtly activates mental representations through exposure to... https://www.jove.com/v/19923 88 2025-09-18T17:24:15+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58459.jpg Combining Eye-tracking Data with an Analysis of Video Content from Free-viewing a Video of a Walk in an Urban Park Environment The objective of the protocol is to detail how to collect video data for use in the laboratory; how to record eye-tracking data of participants looking at the data and how to efficiently analyze the content of the videos that they were looking at using a machine learning... https://www.jove.com/v/58459 505 9000 2019-05-07T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60675.jpg Evaluation of an Exclusive Spur Dike U-Turn Design with Radar-Collected Data and Simulation This protocol describes the process of solving a microscopic traffic problem with simulation. The whole process contains a detailed description of data collection, data analysis, simulation model build, simulation calibration, and sensitive analysis. Modifications and troubleshooting of the method are also... https://www.jove.com/v/60675 701 20400 2020-02-01T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63384.jpg Evaluating the Effect of Roadside Parking on a Dual-Direction Urban Street In this study, the effect of roadside parking on an urban street is analyzed. The entire process consists of traffic data gathering, data processing, operation simulation, simulation calibration, and sensitivity... https://www.jove.com/v/63384 895 3400 2023-01-20T12:30:00+00:00 JoVE no https://visualize.jove.com/37874132-electrochemical-sensor-to-detect-antibiotics-in-milk-based-on-machine-learning-algorithms monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1588.jpg ELIME Enzyme Linked Immuno Magnetic Electrochemical Method for Mycotoxin Detection A protocol to detect trichothecenes (mycotoxins of concern for human health) using a newly developed screening method based on a competitive immunochemical method and a final electrochemical detection is demonstrated. https://www.jove.com/v/1588 731 14300 2009-10-23T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/4282.jpg Bacterial Detection & Identification Using Electrochemical Sensors We describe an electrochemical sensor assay method for rapid bacterial detection and identification. The assay involves a sensor array functionalized with DNA oligonucleotide capture probes for ribosomal RNA (rRNA) species-specific sequences. Sandwich hybridization of target rRNA with the capture probe and a horseradish peroxidase-linked DNA oligonucleotide detector probe produces a measurable amperometric... https://www.jove.com/v/4282 570 28400 2013-04-23T12:00:00+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40786/40786_article_thumb_40786.jpg Microbial Biosensors Microbial biosensors are analytical devices that utilize living microbes to detect specific substances through measurable signals. These devices consist of two main components: biosensing organisms and signal-transducing elements. Biosensing organisms, such as Escherichia coli or Saccharomyces cerevisiae, are typically housed in multiwell plates connected to transducers, enabling rapid, real-time detection of target analytes.Signal Generation MechanismWhen a target analyte—such as... https://www.jove.com/v/40786 77 2026-03-12T13:35:55+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40815/40815_article_thumb_40815.jpg Rapid Identification of Pathogens MALDI-TOF MS has transformed clinical microbiology by offering a rapid and reliable method for pathogen identification. The traditional approach to microbial identification typically involves time-consuming culture techniques and biochemical tests, which can delay the initiation of appropriate antimicrobial therapy. MALDI-TOF MS avoids these delays by using characteristic ribosomal protein mass patterns of microbial cells, enabling accurate species-level identification within minutes.Principle... https://www.jove.com/v/40815 85 2026-05-20T13:51:01+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40816/40816_article_thumb_40816.jpg Automated Microbial Diagnostics Automated diagnostic analyzers have transformed clinical microbiology by providing rapid and reliable methods for pathogen identification and antibiotic susceptibility testing. Among these systems, the Vitek 2 is widely used because it automates the traditionally labor-intensive processes of microbial identification (ID) and antibiotic susceptibility testing (AST), delivering standardized and timely results that are essential for effective patient care.Microbial Identification with ID CardsThe... https://www.jove.com/v/40816 84 2026-03-12T13:35:56+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50474.jpg Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria Lytic phage biosensors and antibody beads are able to discriminate between methicillin resistant (MRSA) and sensitive staphylococcus bacteria. The phages were immobilized by a Langmuir-Blodgett method onto a surface of a quartz crystal microbalance sensor and worked as broad range staphylococcus probes. Antibody beads recognize... https://www.jove.com/v/50474 844 24500 2013-05-08T09:00:00+00:00 JoVE no https://visualize.jove.com/37894000-unsupervised-domain-adaptation-for-mitigating-sensor-variability-and-interspecies-heterogeneity-in-animal-activity-recognition monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14521.jpg Difference from Background: Limit of Detection The limit of detection (LOD) is the smallest amount of analyte that can be distinguished from the background noise. The LOD value corresponds to the concentration at which the analyte signal is three times larger than the standard deviation of the blank signal. Below this value, the analyte signal cannot be differentiated from the background noise. It is calculated by dividing the calibration slope by 3 times the standard deviation of the blank signals. The LOD indicates the presence or absence... https://www.jove.com/v/14521 65 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53004.jpg Evaluation of a Smartphone-based Human Activity Recognition System in a Daily Living Environment A standardized evaluation method was developed for Wearable Mobility Monitoring Systems (WMMS) that includes continuous activities in a realistic daily living environment. Testing with a series of daily living activities can decrease activity recognition sensitivity; therefore, realistic testing circuits are encouraged for valid evaluation of WMMS... https://www.jove.com/v/53004 409 8900 2015-12-11T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58515.jpg Long-term Video Tracking of Cohoused Aquatic Animals: A Case Study of the Daily Locomotor Activity of the Norway Lobster Nephrops norvegicus Here we present a protocol to individually track animals over a long period of time. It uses computer vision methods to identify a set of manually constructed tags by using a group of lobsters as case study, simultaneously providing information on how to house, manipulate, and mark the... https://www.jove.com/v/58515 357 6900 2019-04-08T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65931.jpg Author Spotlight: Addressing Technical and Subjective Challenges in Measuring Classroom Attention This paper proposes an artificial intelligence-based system to automatically detect whether students are paying attention to the class or are distracted. This system is designed to help teachers maintain students' attention, optimize their lessons, and dynamically introduce modifications in order for them to be more... https://www.jove.com/v/65931 397 3800 2023-12-15T14:10:00+00:00 JoVE no https://visualize.jove.com/37921030-why-do-errors-arise-in-artificial-intelligence-diagnostic-tools-in-histopathology-and-how-can-we-minimize-them monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13545.jpg Documentation of Nursing Diagnosis The nurse documents nursing diagnoses and enters them into the patient record. The identified patient's nursing diagnosis is either written out with a plan of care or entered into the electronic health record. In some settings, data-driven computerized decision support systems are in place, allowing for more accurate nursing diagnoses. The database within one of these systems includes diagnostic labels defining characteristics, activities, and indicators for nursing. A nurse enters assessment... https://www.jove.com/v/13545 70 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14507.jpg Systematic Error: Methodological and Sampling Errors In the case of systematic errors, the sources can be identified, and the errors can be subsequently minimized by addressing these sources. According to the source, systematic errors can be divided into sampling, instrumental, methodological, and personal errors. Sampling errors originate from improper sampling methods or the wrong sample population. These errors can be minimized by refining the sampling strategy. Defective instruments or faulty calibrations are the sources of instrumental... https://www.jove.com/v/14507 75 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16480.jpg Accuracy and Errors in Hypothesis Testing Hypothesis testing is a fundamental statistical tool that begins with the assumption that the null hypothesis H0 is true. During this process, two types of errors can occur: Type I and Type II. A Type I error refers to the incorrect rejection of a true null hypothesis, while a Type II error involves the failure to reject a false null hypothesis. In hypothesis testing, the probability of making a Type I error, denoted as α, is commonly set at 0.05. This significance level indicates a 5% chance... https://www.jove.com/v/16480 73 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54780.jpg Utilizing 3D Printing Technology to Merge MRI with Histology: A Protocol for Brain Sectioning The overall goal of this protocol is to accurately align magnetic resonance imaging (MRI) image volumes with histology sections via the creation of customized 3D-printed brain holders and slicer... https://www.jove.com/v/54780 953 15000 2016-12-06T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59915.jpg Optimization, Design and Avoiding Pitfalls in Manual Multiplex Fluorescent Immunohistochemistry Multiplex fluorescent immunohistochemistry is an emerging technology that enables the visualization of multiple cell types within intact formalin-fixed, paraffin embedded (FFPE) tissue. Presented are guidelines for ensuring a successful 7-color multiplex with instructions for optimizing antibodies and reagents, preparing slides, design and tips for avoiding common... https://www.jove.com/v/59915 555 9400 2019-07-26T14:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68083.jpg Detection and Isolation of Cancer in Prostate Biopsies Using Stimulated Raman Histology and Artificial Intelligence Here, we present a standardized protocol for detecting prostate cancer using stimulated Raman histology (SRH) on biopsy samples due to advantages over traditional histopathology, focusing on sample preparation, imaging, and artificial intelligence to improve the cancer-to-tissue ratio. Additionally, it supports biobanking for transcriptomics, organoid or xenograft models, and identification of intraoperative surgical... https://www.jove.com/v/68083 488 60 2025-06-10T12:20:00+00:00 JoVE no https://visualize.jove.com/37933101-from-beasts-to-bytes-revolutionizing-zoological-research-with-artificial-intelligence monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/243.jpg Computer-Generated Animal Model Stimuli Computer-generated stimuli using the Jacky dragon as a... https://app.jove.com/v/243 11000 2007-07-29T00:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/2374.jpg Automated Interactive Video Playback for Studies of Animal Communication Video playback is a widely used technique in animal behavior. We created and evaluated a program that applies rules-based, interactive playback of 3-D computer animations in response to real-time, automated data on subject... https://app.jove.com/v/2374 441 13600 2011-02-09T16:00:00+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19923/19923_article_thumb_19923.jpg Automatic Processing and Automatic Social Behavior Automatic processing refers to the cognitive operations that occur without conscious intent or awareness, playing a fundamental role in shaping social cognition and behavior. These processes enable individuals to navigate complex social environments efficiently by relying on mental shortcuts and pre-existing knowledge structures known as schemas. One of the most influential mechanisms underlying automatic processing is priming, which subtly activates mental representations through exposure to... https://app.jove.com/v/19923 88 376 2025-09-18T17:24:15+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65557.jpg Author Spotlight: AI-Driven Trypanosome Species Detection from Microscopic Images Worldwide medical blood parasites were automatically screened using simple steps on a low-code AI platform. The prospective diagnosis of blood films was improved by using an object detection and classification method in a hybrid deep learning model. The collaboration of active monitoring and well-trained models helps to identify hotspots of trypanosome... https://app.jove.com/v/65557 500 1500 2023-10-27T13:50:00+00:00 JoVE no https://visualize.jove.com/37948257-efficacy-of-medical-device-alarm-integration-into-a-simulated-h-60-integrated-communication-system monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3750.jpg A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation Dual-chamber implantable cardioverter-defibrillators (ICDs) may improve detection of atrial fibrillation as well as differentiation of tachycardias. However, this advantage is undermined by complications associated with the second electrode, which is required in conventional dual chamber devices. Therefore, BIOTRONIK has developed a new electrode called the LinoxSMART S DX that, when used in conjunction with the Lumax DX ICD, offers dual-chamber detection without the risks associated with the... https://www.jove.com/v/3750 1000 26300 2012-02-28T14:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13106.jpg Integrated Healthcare System An integrated healthcare system (IHS) is a set of organizations that provides for or arranges to provide coordinated and continuous service to a defined population. The IHS takes responsibility for that particular population's health status and outcome, both clinically and fiscally. An integrated healthcare system is a well-organized, well-coordinated, and collaborative network. The integrated delivery system is a network that connects different healthcare providers to deliver organized,... https://www.jove.com/v/13106 80 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/13311.jpg Equipments Used To Measure Blood Pressure Direct Method This invasive approach involves cannulating a peripheral artery. During each cardiac contraction, pressure generates mechanical motion within the catheter, transmitted through rigid, fluid-filled tubing to a transducer. This transducer converts mechanical motion into electrical signals displayed as waveforms on a monitor. An automatic flushing system prevents blood backflow. Due to the potential risk of unexpected arterial blood loss, this method is primarily used in intensive... https://www.jove.com/v/13311 90 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51743.jpg Reduced-gravity Environment Hardware Demonstrations of a Prototype Miniaturized Flow Cytometer and Companion Microfluidic Mixing Technology Spaceflight blood diagnostics need innovation. Few demonstrations have been published illustrating in-flight, reduced-gravity health diagnostic technology. Here we present a method for construction and operation of a parabolic flight test rig for a prototype point-of-care flow-cytometry design, with components and preparation strategies adaptable to other... https://www.jove.com/v/51743 839 13800 2014-11-13T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60923.jpg Simulator Training for Endovascular Neurosurgery Simulation of complex, high-risk procedures is critical to the education of medical trainees. A protocol for simulator-based endovascular neurosurgery training in a controlled academic environment is described. The protocol includes stepwise guidelines for trainees of varying levels, with a discussion of the advantages and limitations of this... https://www.jove.com/v/60923 488 3700 2020-05-06T12:30:00+00:00 JoVE no https://visualize.jove.com/38000875-large-language-models-and-their-impact-in-ophthalmology monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14480.jpg Glaucoma: Overview Glaucoma is an eye condition characterized by increased intraocular pressure that damages the retina and optic nerve, leading to irreversible blindness if left untreated. The human eye has various components, including the cornea, iris, pupil, lens, and optic nerve. Aqueous humor is secreted by the epithelium of the ciliary body in the posterior chamber and flows through the trabecular meshwork and canal of Schlemm, maintaining normal intraocular pressure. The trabecular meshwork and the canal... https://www.jove.com/v/14480 85 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64500.jpg Application of Deep Learning-Based Medical Image Segmentation via Orbital Computed Tomography An object segmentation protocol for orbital computed tomography (CT) images is introduced. The methods of labeling the ground truth of orbital structures by using super-resolution, extracting the volume of interest from CT images, and modeling multi-label segmentation using 2D sequential U-Net for orbital CT images are explained for supervised... https://www.jove.com/v/64500 288 2800 2022-11-30T13:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66796.jpg Augmenting Large Language Models via Vector Embeddings to Improve Domain-Specific Responsiveness In this protocol, foundation large language model response quality is improved via augmentation with peer-reviewed, domain-specific scientific articles through a vector embedding mechanism. Additionally, code is provided to aid in performance comparison across large language... https://www.jove.com/v/66796 194 596 2024-12-06T12:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67525.jpg Evidence-based Knowledge Synthesis and Hypothesis Validation: Navigating Biomedical Knowledge Bases via Explainable AI and Agentic Systems This article describes RUGGED (Retrieval Under Graph-Guided Explainable disease Distinction), which integrates Large Language Model (LLM) inference with Retrieval-Augmented Generation (RAG). It draws evidence from expert-curated biomedical knowledge bases and peer-reviewed biomedical publications to synthesize new knowledge from up-to-date information, identify explainable and actionable predictions, and pinpoint promising directions for hypothesis-driven... https://www.jove.com/v/67525 347 236 2025-06-13T13:10:00+00:00 JoVE no https://visualize.jove.com/38002588-deep-learning-techniques-and-imaging-in-otorhinolaryngology-a-state-of-the-art-review monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17950/17950_article_thumb_17950.jpg Cardiopulmonary Resuscitation V: Advanced Airway Management Techniques Airway management is essential in emergency and surgical medicine, ensuring ventilation and oxygenation in patients who cannot maintain their own airway. Clinicians use a range of techniques and devices to secure the airway, depending on the patient’s condition and the clinical context. Key methods include endotracheal intubation, rapid sequence intubation (RSI), supraglottic airway devices, and advanced visualization aids. In cases where these approaches fail, surgical airway interventions are... https://www.jove.com/v/17950 90 2025-06-19T09:39:17+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60407.jpg Learning Modern Laryngeal Surgery in a Dissection Laboratory The purpose of this paper is to illustrate how to organize a reproducible laboratory for laryngeal surgery on affordable and closely similar animal laryngeal models in order to improve anatomical and surgical knowledge and... https://www.jove.com/v/60407 450 8100 2020-03-18T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64500.jpg Application of Deep Learning-Based Medical Image Segmentation via Orbital Computed Tomography An object segmentation protocol for orbital computed tomography (CT) images is introduced. The methods of labeling the ground truth of orbital structures by using super-resolution, extracting the volume of interest from CT images, and modeling multi-label segmentation using 2D sequential U-Net for orbital CT images are explained for supervised... https://www.jove.com/v/64500 288 2800 2022-11-30T13:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66089.jpg Minimally Invasive Murine Laryngoscopy for Close-Up Imaging of Laryngeal Motion During Breathing and Swallowing This protocol describes a serial transoral laryngoscopy approach for mice and rats that permits close-up, unobstructed video imaging of the larynx during breathing and swallowing using an optimized anesthetic regimen and finely tuned endoscopic manipulation... https://www.jove.com/v/66089 442 517 2023-12-01T14:55:00+00:00 JoVE no https://visualize.jove.com/38007753-perspective-of-signal-processing-based-on-brain-computer-interfaces-using-machine-learning-methods monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1677.jpg An Experimental Platform to Study the Closed-loop Performance of Brain-machine Interfaces We use a closed-loop fly-machine interface to investigate general principles in neuronal... https://www.jove.com/v/1677 651 13800 2011-03-10T12:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16029.jpg Signal and System A signal x(t) is a set of data or a time function representing a variable of interest. Signals typically convey information about a phenomenon, such as atmospheric temperature, humidity, human voice, television images, a dog's bark, or birdsongs. More generally, a signal can be a function of more than one independent variable. For instance, images depend on horizontal and vertical positions and can be regarded as two-dimensional signals. However, this text will focus on one-dimensional signals... https://www.jove.com/v/16029 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16030.jpg Classification of Signals In signal processing, signals are classified based on various characteristics: continuous-time versus discrete-time, periodic versus aperiodic, analog versus digital, and causal versus noncausal. Each category highlights distinct properties crucial for understanding and manipulating signals. A continuous-time signal holds a value at every instant in time, representing information seamlessly. In contrast, a discrete-time signal holds values only at specific moments, often denoted as x(n), where... https://www.jove.com/v/16030 90 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16044.jpg Basic Operations on Signals Basic signal operations include time reversal, time scaling, time shifting, and amplitude transformations. These operations are fundamental in signal processing and analysis. Time Reversal mirrors a continuous-time signal about the vertical axis at t=0. This is achieved by substituting t with −t. For example, if a signal x(t) is considered, the time-reversed signal is x(−t). This operation can be graphically represented, showing the mirrored signal. Time Scaling compresses or expands a signal... https://www.jove.com/v/16044 82 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17779.jpg Parallel Processing The brain processes sensory information rapidly due to parallel processing, which involves sending data across multiple neural pathways at the same time. This method allows the brain to manage various sensory qualities, such as shapes, colors, movements, and locations, all concurrently. For instance, when observing a forest landscape, the brain simultaneously processes the movement of leaves, the shapes of trees, the depth between them, and the various shades of green. This enables a quick and... https://www.jove.com/v/17779 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53639.jpg Assessment and Communication for People with Disorders of Consciousness With this experiment, one might be able to detect consciousness in people with disorders of consciousness. Furthermore, the approach can create a simple communication channel that enables people to give simple YES/NO answers to... https://www.jove.com/v/53639 457 9100 2017-08-01T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65007.jpg A Single-Channel and Non-Invasive Wearable Brain-Computer Interface for Industry and Healthcare This paper discusses how to build a brain-computer interface by relying on consumer-grade equipment and steady-state visually evoked potentials. For this, a single-channel electroencephalograph exploiting dry electrodes was integrated with augmented reality glasses for stimuli presentation and output data visualization. The final system was non-invasive, wearable, and portable. https://www.jove.com/v/65007 394 2400 2023-07-07T15:00:00+00:00 JoVE no https://visualize.jove.com/38060821-an-artificial-olfactory-system-based-on-a-memristor-can-simulate-organ-injury-and-functions-in-air-purification monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10852.jpg Olfaction The sense of smell is achieved through the activities of the olfactory system. It starts when an airborne odorant enters the nasal cavity and reaches olfactory epithelium (OE). The OE is protected by a thin layer of mucus, which also serves the purpose of dissolving more complex compounds into simpler chemical odorants. The size of the OE and the density of sensory neurons varies among species; in humans, the OE is only about 9-10 cm2. The olfactory receptors are embedded in the cilia of the... https://www.jove.com/v/10852 85 2025-10-23T11:49:25+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14965.jpg Olfactory Receptors: Location and Structure The process of olfaction, also known as the sense of smell, is a sophisticated chemical response system. The specialized sensory neurons that facilitate this process, known as olfactory receptor neurons, are situated in an upper segment of the nasal cavity, known as the olfactory epithelium. Olfactory sensory neurons are bipolar, with their dendrites extending from the epithelium's apex into the mucus that lines the nasal cavity. Airborne molecules, when inhaled, traverse the olfactory... https://www.jove.com/v/14965 63 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14966.jpg Physiology of Smell and Olfactory Pathway Humans detect odors with the help of specialized cells located in the upper part of the nasal cavity, called olfactory receptor neurons (ORNs). ORNs possess hair-like structures called cilia, which are receptive to sensations from the inhaled air. When an odorant molecule binds to a specific receptor on the cell of the cilia, it leads to a series of events that ultimately cause the ORN to send electrical signals to the olfactory bulb in the brain through the olfactory nerves. The olfactory... https://www.jove.com/v/14966 80 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56076.jpg A Method for Growing Bio-memristors from Slime Mold This paper introduces an improved method for growing bio-memristors out of the plasmodium of Physarum polycephalum. Such a method has proven to decrease growth time, increase component lifespan, standardize electrical observations, and create a protected environment that can be integrated into conventional... https://www.jove.com/v/56076 466 9000 2017-11-02T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60846.jpg Controlled Odor Mimic Permeation Systems for Olfactory Training and Field Testing The Controlled Odor Mimic Permeation System is a simple, field-portable, low-cost method of odor delivery for olfactory testing and training. It is constructed of an odorant retained on an adsorbent material and contained inside of a permeable polymer bag allowing controlled release of the odorant vapor over... https://www.jove.com/v/60846 354 4700 2021-01-28T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65714.jpg Author Spotlight: Exploring Olfactory Influences on Corticospinal Excitability - Insights and Innovations in Neurological Research This paper describes using a breath-synchronized olfactometer to trigger single- and dual-coil transcranial magnetic stimulation (TMS) during odorant presentation synchronized to human nasal breathing. This combination allows us to objectively investigate how pleasant and unpleasant odors impact corticospinal excitability and brain-effective connectivity in a given... https://www.jove.com/v/65714 373 1000 2024-01-19T13:10:00+00:00 JoVE no https://visualize.jove.com/38067837-cost-sensitive-decision-support-for-industrial-batch-processes monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40768/40768_article_thumb_40768.jpg Bioreactor Design and Operational System Bioreactors are engineered vessels designed to cultivate microorganisms under controlled conditions for industrial bioprocessing. They maintain sterility and allow precise regulation of pH, temperature, oxygen, and nutrient levels to optimize microbial growth and metabolite production. Bioreactors range from small laboratory units of 1 liter to industrial systems holding up to 500,000 liters, though only about 75% of their volume is actively used for fermentation. The remaining headspace... https://www.jove.com/v/40768 89 2026-03-12T20:57:31+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40773/40773_article_thumb_40773_TN.jpg Methods of Medium Optimization Optimizing growth media enhances microbial proliferation and maximizes product yield. Statistical experimental design methodologies provide structured and reproducible approaches, offering progressively higher levels of robustness and efficiency.The One-Factor-at-a-Time (OFAT) MethodThe One-Factor-at-a-Time (OFAT) method involves adjusting a single variable while keeping all others constant. However, it cannot detect interactions between variables, often leading to suboptimal outcomes when... https://www.jove.com/v/40773 88 2026-03-12T20:57:38+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40774/40774_article_thumb_40774.jpg Batch vs Continuous Culture Fermentation is a foundational biotechnological process used to produce pharmaceuticals, biofuels, enzymes, and food additives. Among industrial strategies, batch and continuous fermentation are the two most widely applied. Although both rely on microbial conversion of substrates into desired products, they differ markedly in operation, productivity, and suitability for specific applications.Batch fermentation occurs in a closed system in which nutrient media and inoculum are added at the... https://www.jove.com/v/40774 74 2026-03-12T20:57:32+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40775/40775_article_thumb_40775.jpg Fed-Batch Culture Fed-batch culture is a widely used bioprocessing strategy combining aspects of batch culture with controlled substrate feeding to optimize cell growth and product formation. In this semi-closed system, nutrients are strategically added during fermentation, while the accumulated products and biomass remain within the bioreactor until the end of the operation. This controlled addition of substrates allows for better management of growth kinetics, nutrient limitation, and metabolite... https://www.jove.com/v/40775 83 2026-03-12T20:57:38+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40776/40776_article_thumb_40776.jpg Scale-Up Processes The scale-up of microbial fermentation processes is essential in industrial biotechnology, allowing the transition from laboratory-scale experiments to commercial-scale production while aiming to maintain product yield and quality. This process requires meticulous adjustment of equipment design, process parameters, and contamination control strategies to accommodate increasing culture volumes.At the laboratory scale, cultures are typically maintained in 1 to 10-liter glass or autoclavable... https://www.jove.com/v/40776 74 2026-03-12T20:57:33+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40777/40777_article_thumb_40777.jpg Upstream Processing Upstream processing represents a critical phase in biomanufacturing, wherein biological systems such as microorganisms, mammalian cells, or insect cells are cultivated to produce therapeutic proteins, vaccines, enzymes, or other biologically derived products. This phase encompasses all steps from the selection and genetic manipulation of the production organism to the cultivation of cells in bioreactors under tightly controlled environmental conditions.Host Selection and Genetic OptimizationThe... https://www.jove.com/v/40777 87 2026-03-12T20:57:34+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/53940.jpg Procedure to Evaluate the Efficiency of Flocculants for the Removal of Dispersed Particles from Plant Extracts The design-of-experiments procedure presented here allows the evaluation of different flocculants in terms of their ability to aggregate dispersed particles in plant extracts, thus reducing turbidity and the costs of downstream... https://www.jove.com/v/53940 637 9000 2016-04-09T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60423.jpg Automated Counterflow Centrifugal System for Small-Scale Cell Processing Automation is key to upscaling and cost management in cell manufacturing. This manuscript describes the use of a counterflow centrifugal cell processing device for automating the buffer exchange and cell concentration steps for small-scale... https://www.jove.com/v/60423 289 9300 2019-12-12T12:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60577.jpg Process Optimization using High Throughput Automated Micro-Bioreactors in Chinese Hamster Ovary Cell Cultivation Here, we present a detailed procedure to run a Design of Experiment in an automated micro-bioreactor followed by cell harvest and protein quantification using a Protein A... https://www.jove.com/v/60577 568 8500 2020-05-18T12:30:00+00:00 JoVE no https://visualize.jove.com/38074865-systematic-review-of-internet-of-medical-things-for-cardiovascular-disease-prevention-among-australian-first-nations monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17868.jpg Assessment of the Cardiovascular System I: Subjective Data A thorough health history and physical assessment are essential for identifying cardiovascular disease (CVD) symptoms and distinguishing them from other health issues. Initial Enquiry Ask the patient about their primary concern and thoroughly explore all reported symptoms. Medical History Investigate past illnesses affecting the cardiovascular system, such as angina, anemia, rheumatic fever, congenital heart disease, stroke, thrombophlebitis, dysrhythmias, varicosities Inquire about symptoms... https://www.jove.com/v/17868 83 JoVE no https://cloudfront.jove.com/files/ftp_upload/17919/17919_article_thumb_17919.jpg Rheumatic Heart Disease I: Introduction Rheumatic heart disease or RHD is a chronic condition that results from rheumatic fever, causing permanent damage to the heart valves.Etiology and Risk FactorsIt primarily arises from rheumatic fever, an inflammatory disease that can develop after untreated or inadequately treated group A streptococcal (GAS) pharyngitis. Streptococcus spreads through direct contact with oral or respiratory secretions. While the bacteria are the causative agents, factors like malnutrition, overcrowding, poor... https://www.jove.com/v/17919 83 2025-06-19T09:25:14+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17921/17921_article_thumb_17921.jpg Rheumatic Heart Disease III: Medical Management Rheumatic heart disease (RHD) management can be divided into two main strategies: prevention and long-term management.Primary PreventionPrimary prevention focuses on timely diagnosis and management of group A streptococcal pharyngitis to prevent acute rheumatic fever. The most widely used antibiotic for treating this condition is intramuscular benzathine penicillin G.Acute Rheumatic Fever TreatmentThe primary treatment goal for a patient diagnosed with acute rheumatic fever is to suppress the... https://www.jove.com/v/17921 81 2025-06-19T09:25:59+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17926/17926_article_thumb_17926.jpg Coronary Artery Disease IV: Preventive Measures Effective preventive measures for coronary artery disease (CAD) focus on controlling modifiable risk factors, including cholesterol abnormalities and lifestyle changes.Cholesterol ManagementFirst, the Mediterranean diet and the American Heart Association advocate for maintaining low-density lipoprotein (LDL) cholesterol levels below 100 mg/dL, with a more stringent recommendation of below 70 mg/dL for individuals at high risk. LDL cholesterol, often termed "bad cholesterol," can lead to the... https://www.jove.com/v/17926 86 2025-06-19T08:01:34+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17927/17927_article_thumb_17927.jpg Coronary Artery Disease V: Interprofessional Care Interprofessional care for coronary artery disease includes pharmacological therapy and revascularization procedures.Pharmacological therapy for Coronary Artery Disease (CAD) aims to manage symptoms, prevent complications, and improve patient outcomes through various classes of medications:Antiplatelet Agents:Aspirin and Clopidogrel: These medications inhibit platelet aggregation, preventing blood clots, which is crucial for avoiding heart attacks and strokes. Doctors often prescribe these... https://www.jove.com/v/17927 87 2025-06-19T08:03:16+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17931/17931_article_thumb_17931.jpg Acute Coronary Syndrome IV: Interprofessional Care IntroductionThe management of Acute Coronary Syndrome (ACS) aims to minimize myocardial damage, preserve myocardial function, and prevent complications.Initial ManagementInpatient management involves continuous cardiac monitoring, preferably in an ICU, focusing on blood pressure, serum sodium, potassium, and creatinine levels, and urine output. Ongoing pharmacologic management is crucial for stabilizing the patient.Supplemental Oxygen: Administer supplemental oxygen if oxygen saturation is... https://www.jove.com/v/17931 88 2025-06-19T09:29:05+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58132.jpg Hydra, a Computer-Based Platform for Aiding Clinicians in Cardiovascular Analysis and Diagnosis This article presents a protocol based on Hydra — a web-based system for clinical decision support that integrates a full and detailed set of functionalities and services required by physicians for complete cardiovascular analysis, risk assessment, early diagnosis, treatment, and monitoring over... https://www.jove.com/v/58132 471 7600 2018-09-26T13:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59019.jpg A Novel Digital Platform for a Monitored Home-based Cardiac Rehabilitation Program The aim is to promote a new approach to cardiac rehabilitation (CR), using a unique remote patient monitoring system that will enable healthcare providers to monitor CR patients at home at low cost, with the intention of making CR services more accessible and improving compliance. The study is currently underway. https://www.jove.com/v/59019 264 11600 2019-04-19T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59825.jpg Inverse Probability of Treatment Weighting Propensity Score using the Military Health System Data Repository and National Death Index When randomized controlled trials are not feasible, a comprehensive health care data source like the Military Health System Data Repository provides an attractive alternative for retrospective analyses. Incorporating mortality data from the national death index and balancing differences between groups using propensity weighting helps reduce biases inherent in retrospective... https://www.jove.com/v/59825 415 14500 2020-01-08T12:00:00+00:00 JoVE no https://visualize.jove.com/38096741-prospective-effects-of-an-artificial-intelligence-based-computer-aided-detection-system-for-prostate-imaging-on-routine-workflow-and-radiologists-outcomes monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/18491/18491_article_thumb_18491.jpg Imaging Studies IV: Magnetic Resonance Imaging Introduction:Magnetic Resonance Imaging, or MRI, can include a specialized imaging technique of the urinary system known as Magnetic Resonance Urography (MRU). This radiation-free technique uses strong magnetic fields and radio waves to produce detailed images with the help of a computer. MRU is particularly effective for visualizing fluid-filled structures like the kidneys, ureters, and bladder.Applications of MRI in the Genitourinary SystemKidneys and Ureters: MRI detects tumors, cysts,... https://www.jove.com/v/18491 87 2025-06-19T16:29:57+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50341.jpg Detection of Architectural Distortion in Prior Mammograms via Analysis of Oriented Patterns We demonstrate methods for the detection of architectural distortion in prior mammograms. Oriented structures are analyzed using Gabor filters and phase portraits to detect sites of radiating tissue patterns. Each site is characterized and classified using measures to represent spiculating patterns. The methods should assist in the detection of breast... https://www.jove.com/v/50341 824 42900 2013-08-30T12:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67873.jpg A Cognitive Fusion-guided Prostate Biopsy Using Multiparametric Magnetic Resonance Imaging and Transrectal Ultrasound Prostate biopsy is the gold standard diagnostic method for prostate cancer. Cognitive fusion-guided prostate biopsy, which combines transrectal ultrasound with pre-measured MRI parameters, improves biopsy accuracy and enhances the detection rate of clinically significant prostate... https://www.jove.com/v/67873 368 234 2025-03-21T14:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68083.jpg Detection and Isolation of Cancer in Prostate Biopsies Using Stimulated Raman Histology and Artificial Intelligence Here, we present a standardized protocol for detecting prostate cancer using stimulated Raman histology (SRH) on biopsy samples due to advantages over traditional histopathology, focusing on sample preparation, imaging, and artificial intelligence to improve the cancer-to-tissue ratio. Additionally, it supports biobanking for transcriptomics, organoid or xenograft models, and identification of intraoperative surgical... https://www.jove.com/v/68083 488 52 2025-06-10T12:20:00+00:00 JoVE no https://visualize.jove.com/38115587-the-australian-traumatic-brain-injury-initiative-systematic-review-of-predictive-value-of-biological-markers-for-people-with-moderate-severe-traumatic-brain-injury monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40929/40929_article_thumb_40929.jpg Traumatic Brain Injury l: Introduction DefinitionTraumatic brain injury, or TBI, is a disturbance of normal brain function induced by an external mechanical force, such as a direct blow to the head or a penetrating injury. It can affect both brain structure and function, producing a wide range of clinical outcomes. TBI is a heterogeneous condition, meaning its effects may differ based on the type, location, and severity of the injury.Basis of ClassificationTBI is classified based on severity, injury mechanism, or pathophysiology. In... https://www.jove.com/v/40929 88 2026-04-13T23:56:05+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60012.jpg Advanced Diffusion Imaging in The Hippocampus of Rats with Mild Traumatic Brain Injury The overall goal of this procedure is to obtain quantitative microstructural information of the hippocampus in a rat with mild traumatic brain injury. This is done using an advanced diffusion-weighted magnetic resonance imaging protocol and region-of-interest based analysis of parametric diffusion... https://www.jove.com/v/60012 633 8500 2019-08-14T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61504.jpg Systems Analysis of the Neuroinflammatory and Hemodynamic Response to Traumatic Brain Injury This protocol presents methods to characterize the neuroinflammatory and hemodynamic response to mild traumatic brain injury and to integrate these data as part of a multivariate systems analysis using partial least squares... https://www.jove.com/v/61504 441 3200 2022-05-27T13:15:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67011.jpg Development of an Uncomplicated Mild Traumatic Brain Injury Model Modified by Weight-Drop Method and Evidenced by Magnetic Resonance Imaging Here, we present a protocol to establish a closed-head injury animal model replicating the neuroimage outcome of uncomplicated mild traumatic brain injury with the preserved brain structure in the acute phase and long-term brain atrophy. Longitudinal magnetic resonance imaging is the primary method used for evidence. https://www.jove.com/v/67011 516 287 2025-04-11T12:20:00+00:00 JoVE no https://visualize.jove.com/38132474-polarization-and-chaos-game-based-fingerprinting-of-molecular-targets-of-listeria-monocytogenes-vaccine-and-fully-virulent-strains monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/19557/19557_article_thumb_19557.jpg Modern Molecular Taxonomy Advancements in molecular biology have revolutionized the identification and characterization of bacteria, with multiple methods leveraging DNA sequencing for enhanced precision. As sequencing technologies improve and costs decline, these approaches are increasingly used in clinical, environmental, and evolutionary studies.Multilocus Sequence Typing (MLST) examines several housekeeping genes, essential chromosomal genes encoding cellular functions, to distinguish strains. Approximately... https://www.jove.com/v/19557 89 2025-06-12T16:19:23+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40815/40815_article_thumb_40815.jpg Rapid Identification of Pathogens MALDI-TOF MS has transformed clinical microbiology by offering a rapid and reliable method for pathogen identification. The traditional approach to microbial identification typically involves time-consuming culture techniques and biochemical tests, which can delay the initiation of appropriate antimicrobial therapy. MALDI-TOF MS avoids these delays by using characteristic ribosomal protein mass patterns of microbial cells, enabling accurate species-level identification within minutes.Principle... https://www.jove.com/v/40815 85 2026-05-20T20:51:01+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54165.jpg Subtyping of Campylobacter jejuni ssp. doylei Isolates Using Mass Spectrometry-based PhyloProteomics MSPP Mass spectrometry-based phyloproteomics (MSPP) was used to type a collection of Campylobacter jejuni ssp. doylei isolates at the strain level in comparison to multilocus sequence typing... https://www.jove.com/v/54165 583 8600 2016-10-30T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56585.jpg Development of an Electrochemical DNA Biosensor to Detect a Foodborne Pathogen A protocol for the development of an electrochemical DNA biosensor comprising a polylactic acid-stabilized, gold nanoparticles-modified, screen-printed carbon electrode to detect Vibrio parahaemolyticus is... https://www.jove.com/v/56585 1036 13100 2018-06-03T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65435.jpg Author Spotlight: Leptospira DNA Detection in Water for Environmental Analysis and Disease Surveillance In this study, a dot-blot application was designed to detect Leptospira from the three main clades in water samples. This method allows for the identification of minimal DNA quantities specifically targeted by a digoxigenin-labeled probe, easily detected by an anti-digoxigenin antibody. This approach is a valuable and satisfactory tool for screening... https://www.jove.com/v/65435 365 1200 2024-06-14T12:30:00+00:00 JoVE no https://visualize.jove.com/38133202-lake-avernus-has-turned-red-bioindicator-monitoring-unveils-the-secrets-of-gates-of-hades monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/18101/18101_article_thumb_18101.jpg Underflow Gates Underflow gates are vital for controlling water flow in irrigation canals. The three main types of underflow gates — vertical, radial, and drum gates — serve different purposes while ensuring effective flow management. Vertical gates move up and down, generating a free-flowing water jet; radial gates pivot to regulate the flow; and drum gates rotate for precise adjustments. The flow through these gates is influenced by downstream conditions, resulting in free or drowned outflow.Free and Drowned... https://www.jove.com/v/18101 90 2025-03-26T15:05:33+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/19582/19582_article_thumb_19582.jpg Red Algae Red algae, also known as rhodophytes, are primarily found in marine environments, though some species inhabit freshwater and terrestrial ecosystems. These organisms exist in both unicellular and multicellular forms, with some multicellular varieties reaching macroscopic sizes.As phototrophic organisms, red algae contain chlorophyll a; however, their chloroplasts lack chlorophyll b. Instead, they possess phycobiliproteins, which serve as major light-harvesting pigments, similar to those found in... https://www.jove.com/v/19582 83 2025-06-12T09:26:52+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40751/40751_article_thumb_40751.jpg Acid Mine Drainage Mining activities that disturb sulfide-rich rocks, particularly those containing pyrite (FeS₂), initiate a cascade of geochemical and microbiological processes with serious environmental implications. When exposed to air and water, pyrite undergoes oxidation, releasing sulfate, ultimately forming sulfuric acid and mobilizing heavy metals into surrounding water systems. This phenomenon, known as acid mine drainage (AMD), results in low pH waters laden with toxic elements that threaten aquatic... https://www.jove.com/v/40751 79 2026-03-12T13:57:39+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52558.jpg Use of Chironomidae Diptera Surface-Floating Pupal Exuviae as a Rapid Bioassessment Protocol for Water Bodies Rapid bioassessment protocols using benthic macroinvertebrates are often used to monitor and assess water quality. An efficient protocol involves collections of Chironomidae surface-floating pupal exuviae (SFPE). Here, techniques for field collection, laboratory processing, slide mounting, and identification of Chironomidae SFPE are... https://www.jove.com/v/52558 507 11700 2015-07-24T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56466.jpg Continuous Hydrologic and Water Quality Monitoring of Vernal Ponds Understanding the ecosystem services and processes provided by vernal ponds and the impacts of anthropogenic activities on their ability to provide these services requires intensive hydrologic monitoring. This sampling protocol using in-situ monitoring equipment was developed to understand the impact of anthropogenic activities on water levels and... https://www.jove.com/v/56466 397 9300 2017-11-13T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61889.jpg Early Detection of Cyanobacterial Blooms and Associated Cyanotoxins using Fast Detection Strategy A fast-multidisciplinarystrategy for early detection of cyanobacterial blooms and associated cyanotoxins is described here. It allows for the detection of cyanobacteria and related cyanotoxins in water samples and in organic matrices, such as bivalve samples, in 24... https://www.jove.com/v/61889 433 3900 2021-02-25T12:30:00+00:00 JoVE no https://visualize.jove.com/38136025-modelling-and-simulation-of-the-combined-use-of-iabp-and-impella-as-a-rescue-procedure-in-cardiogenic-shock-an-alternative-for-non-transplant-centres monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17948/17948_article_thumb_17948.jpg Cardiopulmonary Resuscitation III: AED Use Introduction to AEDAn Automated External Defibrillator (AED) is a portable medical device that analyzes the heart's rhythm and, if necessary, delivers an electrical shock to help the heart re-establish an effective rhythm during sudden cardiac arrest (SCA). SCA occurs when the heart suddenly and unexpectedly stops beating, leading to a loss of blood flow to the brain and other vital organs. In such emergencies, time is of the essence, and using an AED, combined with Cardiopulmonary... https://www.jove.com/v/17948 83 2025-06-19T09:38:36+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/17949/17949_article_thumb_17949.jpg Cardiopulmonary Resuscitation IV: Pharmacological Management Pharmacologic intervention is crucial in treating cardiac arrest patients during ACLS or Advanced Cardiovascular Life Support. The ACLS algorithms guide the administration of specific drugs based on the patient's cardiac arrest rhythm, which includes pulseless ventricular tachycardia (VT), ventricular fibrillation (VF), asystole, and pulseless electrical activity (PEA).EpinephrineIndication: Epinephrine is the first-line drug for all cardiac arrest rhythms.Mechanism of Action: Epinephrine... https://www.jove.com/v/17949 85 2025-07-31T13:24:37+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62110.jpg Utilizing Percutaneous Ventricular Assist Devices in Acute Myocardial Infarction Complicated by Cardiogenic Shock Percutaneous ventricular assist devices are increasingly being utilized in patients with acute myocardial infarction and cardiogenic shock. Herein, we discuss the mechanism of action and hemodynamic effects of such devices. We also review algorithms and best practices for the implantation, management and weaning of these complex... https://www.jove.com/v/62110 370 3300 2021-06-12T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62132.jpg The Intra-Aortic Balloon Pump We describe the steps for the percutaneous implantation of the intra-aortic balloon pump (IABP), a mechanical circulatory support device. It acts by counterpulsation, inflating at the onset of diastole, augmenting diastolic aortic pressure and improving coronary blood flow and systemic perfusion, and deflating before systole, reducing left ventricular... https://www.jove.com/v/62132 373 21400 2021-02-05T14:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/62140.jpg Use of a Percutaneous Ventricular Assist Device/Left Atrium to Femoral Artery Bypass System for Cardiogenic Shock The following article describes the stepwise procedure for placement of a device (e.g., Tandemheart) in cardiogenic shock (CS) that is a percutaneous left ventricular assist device (pLVAD) and a left atrial to femoral artery bypass (LAFAB) system that bypasses and supports the left ventricle (LV) in CS. https://www.jove.com/v/62140 459 3600 2021-08-16T13:00:00+00:00 JoVE no https://visualize.jove.com/38156987-network-motif-delay-differential-analysis-of-brain-activity-during-seizures monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15215.jpg Seizures: Classification Epilepsy is primarily characterized by unpredictable seizures, either provoked by an identifiable factor, such as injury or illness, or unprovoked, occurring spontaneously without apparent cause. Seizures are typically classified into two main categories: focal and generalized seizures. Focal Seizures Focal seizures originate from specific regions of the brain. These seizures are further sub-classified into two types: Focal aware seizures: In these seizures, the person remains conscious... https://www.jove.com/v/15215 73 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51442.jpg Network Analysis of the Default Mode Network Using Functional Connectivity MRI in Temporal Lobe Epilepsy The Default Mode Network (DMN) in Temporal Lobe Epilepsy (TLE) is analyzed in the resting state of the brain using seed-based functional connectivity MRI... https://www.jove.com/v/51442 729 18100 2014-08-05T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54746.jpg Network Analysis of Foramen Ovale Electrode Recordings in Drug-resistant Temporal Lobe Epilepsy Patients This protocol describes a procedure to track the evolution of mesial network measures in temporal lobe epilepsy (TLE) patients. It is based on the combination of intracranial recordings with a novel numerical technique for data analysis. Specifically, we present a protocol for network analyses of foramen ovale... https://www.jove.com/v/54746 572 12400 2016-12-18T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67065.jpg Author Spotlight: Unraveling Seizure Dynamics and Novel Therapeutics for Status Epilepticus Using CMOS High-Density Microelectrode Array Systems Here, we outline a protocol for using complementary metal-oxide-semiconductor high-density microelectrode array systems (CMOS-HD-MEAs) to record seizure-like activity from ex vivo brain... https://www.jove.com/v/67065 388 2400 2024-09-27T14:00:00+00:00 JoVE no https://visualize.jove.com/38165976-improved-support-vector-machine-based-on-cnn-svd-for-vision-threatening-diabetic-retinopathy-detection-and-classification monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40911/40911_article_thumb_40911.jpg Diabetic Retinopathy DefinitionDiabetic retinopathy is a microvascular complication of diabetes affecting the retinal blood vessels.Risk FactorsDiabetic retinopathy is present in almost all individuals with type 1 diabetes and more than 60% of those with type 2 diabetes after two decades of disease.The risk increases with poor glycemic control, hypertension, dyslipidemia, smoking, pregnancy, and puberty.Although cataracts and glaucoma are also more frequent in people with diabetes, retinopathy remains the leading... https://www.jove.com/v/40911 87 2026-04-13T21:37:50+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/56137.jpg Using Retinal Imaging to Study Dementia The retina shares prominent similarities with the brain and thus represents a unique window to study vasculature and neuronal structure in the brain non-invasively. This protocol describes a method to study dementia using retinal imaging techniques. This method can potentially aid in diagnosis and risk assessment of... https://www.jove.com/v/56137 557 21600 2017-11-06T17:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66123.jpg Author Spotlight: Understanding Retinal Vessel Resilience and Disease Progression A protection assay was developed to monitor the retinal vasculature's resilience to death from diabetes/diabetic retinopathy-related insults such as oxidative stress and cytokines. https://www.jove.com/v/66123 276 1100 2024-01-12T14:05:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67220.jpg Quantification of Diabetes-induced Adherent Leukocytes in Retinal Vasculature We demonstrate a method to label the walls of the retinal vasculature and adherent leukocytes. These adherent leukocytes can then be counted under a fluorescence microscope as a parameter of inflammation or the response of that inflammation to therapies. https://www.jove.com/v/67220 354 284 2025-01-24T13:20:00+00:00 JoVE no https://visualize.jove.com/38177983-identification-of-difficult-laryngoscopy-using-an-optimized-hybrid-architecture monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/17950/17950_article_thumb_17950.jpg Cardiopulmonary Resuscitation V: Advanced Airway Management Techniques Airway management is essential in emergency and surgical medicine, ensuring ventilation and oxygenation in patients who cannot maintain their own airway. Clinicians use a range of techniques and devices to secure the airway, depending on the patient’s condition and the clinical context. Key methods include endotracheal intubation, rapid sequence intubation (RSI), supraglottic airway devices, and advanced visualization aids. In cases where these approaches fail, surgical airway interventions are... https://www.jove.com/v/17950 90 2025-06-19T16:39:17+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60407.jpg Learning Modern Laryngeal Surgery in a Dissection Laboratory The purpose of this paper is to illustrate how to organize a reproducible laboratory for laryngeal surgery on affordable and closely similar animal laryngeal models in order to improve anatomical and surgical knowledge and... https://www.jove.com/v/60407 450 8100 2020-03-18T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64648.jpg Point-of-Care Ultrasound: A Review of Ultrasound Parameters for Predicting Difficult Airways A point-of-care ultrasound (POCUS) is a simple, non-invasive, and portable tool that enables dynamic airway assessment. Several studies have attempted to determine the role of ultrasound parameters as an adjunct to clinical examination in predicting difficult... https://www.jove.com/v/64648 501 1500 2023-04-07T13:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66089.jpg Minimally Invasive Murine Laryngoscopy for Close-Up Imaging of Laryngeal Motion During Breathing and Swallowing This protocol describes a serial transoral laryngoscopy approach for mice and rats that permits close-up, unobstructed video imaging of the larynx during breathing and swallowing using an optimized anesthetic regimen and finely tuned endoscopic manipulation... https://www.jove.com/v/66089 442 512 2023-12-01T14:55:00+00:00 JoVE no https://visualize.jove.com/38185459-the-artificial-intelligence-revolution-in-stroke-care-a-decade-of-scientific-evidence-in-review monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40915/40915_article_thumb_40915.jpg Ischemic Stroke l: Introduction Ischemic stroke is an acute cerebrovascular condition in which blood flow to a brain region is suddenly interrupted, leading to tissue infarction. Neurons depend on continuous oxygen and glucose supply, so even brief reductions in perfusion cause energy failure, ionic imbalance, and irreversible injury. Ischemic strokes are classified into thrombotic and embolic types based on their underlying mechanisms.Thrombotic MechanismsThrombotic stroke develops when a clot forms within a cerebral artery. https://www.jove.com/v/40915 75 2026-04-13T21:37:39+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65994.jpg Author Spotlight: Rehabilitation of Stroke Patients With a Digital Occupational Training System The current protocol outlines how the VR-based digital occupational training system enhances the rehabilitation of patients with cognitive impairment and upper limb dysfunction following a... https://www.jove.com/v/65994 455 1200 2023-12-29T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66938.jpg Author Spotlight: Enhancing Post-Stroke Upper Limb Rehabilitation with Robotic Technologies for Improved Motor Recovery and Functional Outcomes This protocol describes an upper limb rehabilitation robot that provides intelligent feedback through four modes. These modes enhance upper limb function and flexibility, thereby improving patients' quality of... https://www.jove.com/v/66938 289 771 2024-09-06T13:50:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67601.jpg Brain-Computer Interface-controlled Upper Limb Robotic System for Enhancing Daily Activities in Stroke Patients This study introduces a brain-computer interface (BCI) system for stroke patients, which combines electroencephalography and electrooculography signals to control an upper limb robotic hand, enhancing daily activities. The evaluation used the Berlin Bimanual Test for Stroke... https://www.jove.com/v/67601 371 394 2025-04-18T13:10:00+00:00 JoVE no https://visualize.jove.com/38216788-review-of-applications-of-artificial-intelligence-ai-methods-in-crop-research monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11095.jpg Light Acquisition In order to produce glucose, plants need to capture sufficient light energy. Many modern plants have evolved leaves specialized for light acquisition. Leaves can be only millimeters in width or tens of meters wide, depending on the environment. Due to competition for sunlight, evolution has driven the evolution of increasingly larger leaves and taller plants, to avoid shading by their neighbors with contaminant elaboration of root architecture and mechanisms to transport water and nutrients. <br... https://www.jove.com/v/11095 136 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/11113.jpg Plant Breeding and Biotechnology Crop cultivation has a long history in human civilization, with records showing the cultivation of cereal plants beginning at around 8000 BC. This early plant breeding was developed primarily to provide a steady supply of food. As humans' understanding of genetics advanced, improved crop varieties could be achieved more quickly. Artificial selection could be more directed, and crop varieties enhanced for favorable traits more quickly to produce better, more robust, or more palatable plants. <br... https://www.jove.com/v/11113 119 JoVE no https://cloudfront.jove.com/CDNSource/teasers/58695.jpg Cereal Crop Ear Counting in Field Conditions Using Zenithal RGB Images We present a protocol for counting durum wheat and barley ears, using natural color (RGB) digital photographs taken in natural sunlight under field conditions. With minimal adjustments for camera parameters and some environmental condition limitations, the technique provides precise and consistent results across a range of growth... https://www.jove.com/v/58695 709 9300 2019-02-02T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59835.jpg Robotic Sensing and Stimuli Provision for Guided Plant Growth Distributed robot nodes provide sequences of blue light stimuli to steer the growth trajectories of climbing plants. By activating natural phototropism, the robots guide the plants through binary left-right decisions, growing them into predefined patterns that by contrast are not possible when the robots are... https://www.jove.com/v/59835 482 8000 2019-07-01T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61280.jpg A Telemetric, Gravimetric Platform for Real-Time Physiological Phenotyping of Plant–Environment Interactions This high-throughput, telemetric, whole-plant water relations gravimetric phenotyping method enables direct and simultaneous real-time measurements, as well as the analysis of multiple yield-related physiological traits involved in dynamic plant–environment... https://www.jove.com/v/61280 930 11600 2020-08-05T13:00:00+00:00 JoVE no https://visualize.jove.com/38271715-spike-sorting-in-the-presence-of-stimulation-artifacts-a-dynamical-control-systems-approach monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16094.jpg Feedback control systems Feedback control systems are categorized in various ways based on their design, analysis, and signal types. Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity... https://www.jove.com/v/16094 86 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/16127.jpg Time-Domain Interpretation of PD Control Proportional-Derivative (PD) control is a widely used control method in various engineering systems to enhance stability and performance. In a system with only proportional control, common issues include high maximum overshoot and oscillation, observed in both the error signal and its rate of change. This behavior can be divided into three distinct phases: initial overshoot, subsequent undershoot, and gradual stabilization. Consider the example of control of motor torque. Initially, a positive... https://www.jove.com/v/16127 67 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50941.jpg A Simple Stimulatory Device for Evoking Point-like Tactile Stimuli: A Searchlight for LFP to Spike Transitions To elucidate the complex transition from Local Field Potentials (LFPs) to spikes a suitable stimulator for light mechanical peripheral stimuli was built. As an application, the spiking activities recorded from somatosensory cortex were analyzed by a multi-objective optimization strategy. The results demonstrated that the proposed stimulator was able to deliver tactile stimuli with millisecond and millimeter... https://www.jove.com/v/50941 454 9900 2014-03-25T13:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/55217.jpg A Visual Guide to Sorting Electrophysiological Recordings Using 'SpikeSorter' The article shows how to use the program SpikeSorter to detect and sort spikes in extracellular recordings made with multi-electrode... https://www.jove.com/v/55217 631 11100 2017-02-10T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59812.jpg Using Neuron Spiking Activity to Trigger Closed-Loop Stimuli in Neurophysiological Experiments This protocol demonstrates how to use an electrophysiological system for closed-loop stimulation triggered by neuronal activity patterns. Sample Matlab code that can be easily modified for different stimulation devices is also... https://www.jove.com/v/59812 319 7000 2019-11-12T11:00:00+00:00 JoVE no https://visualize.jove.com/38275492-detection-of-anticipatory-dynamics-between-a-pair-of-zebrafish monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14157.jpg Sign Test for Matched Pairs The sign test for matched pairs offers a robust method for comparing two paired samples, often for the effects of an intervention in one of them. This method is very useful in situations where the underlying distribution of the data is unknown. The test compares two related samples—often pre- and post-treatment measurements on the same subjects—to determine if there are significant differences in their median values. To conduct the sign test, we first calculate the differences in value between... https://www.jove.com/v/14157 77 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50622.jpg Automated High-throughput Behavioral Analyses in Zebrafish Larvae Our laboratory developed a novel high-throughput automated imaging system that is useful for the detection of several different behaviors in 7-day-old zebrafish larvae. The system can be used for detecting subtle changes in behavior after the larvae have been exposed to environmental toxicants or... https://www.jove.com/v/50622 568 15300 2013-07-04T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50681.jpg Using an Automated 3D-tracking System to Record Individual and Shoals of Adult Zebrafish The use of a 3D automatic video system that can track individual and groups of zebrafish is described. As application example we explore the effects of the NMDA-receptor antagonist MK-801 on shoals of... https://www.jove.com/v/50681 843 11000 2013-12-05T16:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/50925.jpg Analysis of Skeletal Muscle Defects in Larval Zebrafish by Birefringence and Touch-evoke Escape Response Assays The zebrafish is now an established and powerful tool for modeling muscular dystrophies, congenital myopathies, and related neuromuscular diseases. Birefringence and touch-evoked escape behavior are two common noninvasive assays used to determine the degree of muscular disorganization and locomotive impairment of zebrafish embryos during early... https://www.jove.com/v/50925 481 7900 2013-12-13T13:45:00+00:00 JoVE no https://visualize.jove.com/38279797-the-australian-traumatic-brain-injury-initiative-systematic-review-of-the-effect-of-acute-interventions-on-outcome-for-people-with-moderate-severe-traumatic-brain-injury monthly 0.9 https://cloudfront.jove.com/files/ftp_upload/40929/40929_article_thumb_40929.jpg Traumatic Brain Injury l: Introduction DefinitionTraumatic brain injury, or TBI, is a disturbance of normal brain function induced by an external mechanical force, such as a direct blow to the head or a penetrating injury. It can affect both brain structure and function, producing a wide range of clinical outcomes. TBI is a heterogeneous condition, meaning its effects may differ based on the type, location, and severity of the injury.Basis of ClassificationTBI is classified based on severity, injury mechanism, or pathophysiology. In... https://www.jove.com/v/40929 88 2026-04-13T23:56:05+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/51781.jpg Controlled Cortical Impact Model for Traumatic Brain Injury Traumatic brain injuries (TBIs) remain a serious health problem. Using the controlled cortical impact surgery model, research on the effects of TBI and possible treatment methods may be... https://www.jove.com/v/51781 330 28600 2014-08-05T16:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/60027.jpg Murine Model of Controlled Cortical Impact for the Induction of Traumatic Brain Injury Here we describe a protocol for the induction of murine traumatic brain injury via an open-head controlled cortical... https://www.jove.com/v/60027 301 10400 2019-08-16T14:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61504.jpg Systems Analysis of the Neuroinflammatory and Hemodynamic Response to Traumatic Brain Injury This protocol presents methods to characterize the neuroinflammatory and hemodynamic response to mild traumatic brain injury and to integrate these data as part of a multivariate systems analysis using partial least squares... https://www.jove.com/v/61504 441 3100 2022-05-27T13:15:00+00:00 JoVE no https://visualize.jove.com/38283379-artificial-intelligence-as-diagnostic-modality-for-keratoconus-a-systematic-review-and-meta-analysis monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18158.jpg Intelligence The term "intelligence" is complex because it refers to both behavior and individuals, and its interpretation varies across cultures. European Americans tend to link intelligence with reasoning and cognitive skills, while in Kenya, it is tied to responsible participation in family and social life. In Uganda, intelligence is seen as the ability to know the right actions and carry them out effectively, while the Iatmul people of Papua New Guinea associate it with the capacity to remember detailed... https://www.jove.com/v/18158 87 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/18162.jpg Measures of Intelligence Psychologists measure intelligence by using standardized tests that produce a score known as the intelligence quotient or IQ. To understand IQ tests, it's important to recognize the key principles behind their construction: validity, reliability, and standardization. Validity refers to how well a test measures what it claims to measure. An intelligence test should accurately assess intelligence rather than another characteristic, like anxiety. Criterion validity is one way to evaluate this; it... https://www.jove.com/v/18162 89 JoVE no https://cloudfront.jove.com/CDNSource/teasers/57104.jpg Full-Field Optical Coherence Microscopy for Histology-Like Analysis of Stromal Features in Corneal Grafts We describe use of full-field optical coherence microscopy as a method for high quality assessment of corneal donor stroma. This protocol can be used to identify features indicative of health or disease, and is aimed at improving the screening and selection of donor tissues, and hence the results of... https://www.jove.com/v/57104 471 1600 2022-10-21T12:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66597.jpg Author Spotlight: Establishing a Practical and Cost-Effective Protocol for Corneal Sensitivity Testing in Clinical Settings Corneal sensitivity testing provides insight into the health of the corneal nerves and helps diagnose ocular surface diseases. We present a concise protocol to qualitatively assess corneal sensitivity that can be readily used by eye care providers across clinical settings. https://www.jove.com/v/66597 240 1900 2024-08-02T13:20:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67127.jpg Author Spotlight: Anterior HR-OCT as a Non-Invasive Tool for Characterizing Ocular Surface Squamous Neoplasia Anterior segment high-resolution optical coherence tomography (HR-OCT) is a promising non-invasive modality for the diagnosis and therapeutic evaluation of ocular surface squamous neoplasia (OSSN). Here, the system setup, scanning technique, and representative diagnostic results are... https://www.jove.com/v/67127 375 1200 2024-08-09T14:40:00+00:00 JoVE no https://visualize.jove.com/38287028-harnessing-synthetic-active-particles-for-physical-reservoir-computing monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14207.jpg Ampere-Maxwell's Law: Problem-Solving A parallel-plate capacitor with capacitance C, whose plates have area A and separation distance d, is connected to a resistor R and a battery of voltage V. The current starts to flow at t = 0. What is the displacement current between the capacitor plates at time t? From the properties of the capacitor, what is the corresponding real current? To solve the problem, we can use the equations from the analysis of an RC circuit and Maxwell's version of Ampère's law. For the first part of the problem,... https://www.jove.com/v/14207 77 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/14584.jpg Precipitate Formation and Particle Size Control In precipitation gravimetry, the precipitating agent should react specifically or selectively with the analyte. While a specific reagent reacts with the analyte alone, a selective reagent can react with a limited number of chemical species. The obtained precipitate should be either a pure substance of known composition or easily converted to one by a simple process, such as ignition or drying. In addition, the precipitate should be insoluble and easily filterable. In general, filterability... https://www.jove.com/v/14584 76 JoVE no https://cloudfront.jove.com/CDNSource/teasers/52842.jpg Fabrication and Operation of a Nano-Optical Conveyor Belt The scalability and resolution of conventional optical manipulation techniques are limited by diffraction. We circumvent the diffraction limit and describe a method of optically transporting nanoparticles across a chip using a gold surface patterned with a path of closely spaced C-shaped plasmonic... https://www.jove.com/v/52842 670 11600 2015-08-26T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/54193.jpg Microfluidic Pneumatic Cages: A Novel Approach for In-chip Crystal Trapping, Manipulation and Controlled Chemical Treatment Herein, we describe the fabrication and operation of a double-layer microfluidic system made of polydimethylsiloxane (PDMS). We demonstrate the potential of this device for trapping, directing the coordination pathway of a crystalline molecular material and controlling chemical reactions onto on-chip trapped structures. https://www.jove.com/v/54193 574 9500 2016-07-12T15:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61943.jpg Real-Time Proxy-Control of Re-Parameterized Peripheral Signals using a Close-Loop Interface We present protocols and methods of analyses to build co-adaptive interfaces that stream, parameterize, analyze, and modify human body and heart signals in close-loop. This setup interfaces signals derived from the peripheral and central nervous systems of the person with external sensory inputs to help track biophysical change. https://www.jove.com/v/61943 714 4400 2021-05-08T14:30:00+00:00 JoVE no https://visualize.jove.com/42174001-a-digital-twin-and-deep-learning-ensemble-for-cyber-attack-detection-in-industrial-control-systems-at-the-iot-edge monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/68888.jpg Simulation of a Scaled Assembly Process with Collaboration of a Robotic Arm and Monitoring through a Vision System for Quality Control Here, we present a protocol for the simulation and monitoring of a scaled semi-automated assembly process, through the collaboration of a collaborative robot and verification via a computer vision system for quality control. https://www.jove.com/v/68888 347 2025-08-29T20:45:00+00:00 JoVE no https://visualize.jove.com/42187471-rt-afnet-a-hybrid-resnet-transformer-architecture-with-multi-scale-fusion-for-atrial-fibrillation-detection monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3103.jpg High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation This report provides a detailed description of the methodology and results of simultaneous endocardial and epicardial optical mapping of electrical excitation in the intact left atrium of a Langendorff-perfused sheep heart during stretch-induced atrial fibrillation. https://www.jove.com/v/3103 557 2011-07-29T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/3750.jpg A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation Dual-chamber implantable cardioverter-defibrillators (ICDs) may improve detection of atrial fibrillation as well as differentiation of tachycardias. However, this advantage is undermined by complications associated with the second electrode, which is required in conventional dual chamber devices. Therefore, BIOTRONIK has developed a new electrode called the LinoxSMART S DX that, when used in conjunction with the Lumax DX ICD, offers dual-chamber detection without the risks associated with the... https://www.jove.com/v/3750 1000 2012-02-28T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/63598.jpg Estimating Bilateral Atrial Function by Cardiovascular Magnetic Resonance Feature Tracking in Patients with Paroxysmal Atrial Fibrillation The atrial function is associated with the strain and strain rate. The cardiac magnetic resonance feature tracking (CMR-FT) technique was used in this study to quantify left and right atrial global and segmental longitudinal strain and strain rate in individuals with paroxysmal atrial fibrillation. https://www.jove.com/v/63598 490 2022-07-20T12:45:00+00:00 JoVE no https://visualize.jove.com/42191663-artificial-intelligence-in-neuroradiology-a-review-of-fda-regulated-algorithms monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/50887.jpg Lesion Explorer: A Video-guided, Standardized Protocol for Accurate and Reliable MRI-derived Volumetrics in Alzheimer's Disease and Normal Elderly Lesion Explorer (LE) is a semi-automatic, image-processing pipeline developed to obtain regional brain tissue and subcortical hyperintensity lesion volumetrics from structural MRI of Alzheimer's disease and normal elderly. To ensure a high level of accuracy and reliability, the following is a video-guided, standardized protocol for LE's manual procedures. https://www.jove.com/v/50887 770 2014-04-14T23:45:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66014.jpg Reliability of Artificial Intelligence-Based Cone Beam Computed Tomography Integration with Digital Dental Images A process of registering cone-beam computed tomography scans and digital dental images has been presented using artificial intelligence (AI) -assisted identification of landmarks and merging. A comparison with surface-based registration shows that AI-based digitization and integration are reliable and reproducible. https://www.jove.com/v/66014 349 2024-02-23T21:35:00+00:00 JoVE no https://visualize.jove.com/42235350-artificial-intelligence-based-techniques-for-brain-tumor-analysis-a-systematic-review monthly 0.9 https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/17752.jpg Brain Imaging Brain imaging technologies provide critical insights into both the structure and function of the human brain, enabling medical professionals and researchers to diagnose, study, and treat neurological disorders or psychiatric disorders more effectively. These technologies include computerized axial tomography (CAT or CT scans), positron-emission tomography (PET scans), magnetic resonance imaging (MRI), functional magnetic resonance imaging (fMRI), and Transcranial Magnetic Stimulation (TMS).<br... https://www.jove.com/v/17752 74 JoVE no https://cloudfront.jove.com/CDNSource/teasers/59278.jpg Longitudinal Intravital Imaging of Brain Tumor Cell Behavior in Response to an Invasive Surgical Biopsy Here we describe a method for high-resolution time-lapse multiphoton imaging of brain tumor cells before and after invasive surgical intervention (e.g., biopsy) within the same living animal. This method allows studying the impact of these invasive surgical procedures on tumor cells' migratory, invasive, and proliferative behavior at a single cell level. https://www.jove.com/v/59278 557 2019-05-03T20:30:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/61272.jpg Modeling Brain Metastases Through Intracranial Injection and Magnetic Resonance Imaging Intracranial brain metastasis modeling is complicated by an inability to monitor tumor size and response to treatment with precise and timely methods. The presented methodology couples intracranial tumor injection with magnetic resonance imaging analysis, which when combined, cultivates precise and consistent injections, enhanced animal monitoring, and accurate tumor volume measurements. https://www.jove.com/v/61272 404 2020-06-07T22:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/64048.jpg Implementation of Minimally Invasive Brain Tumor Resection in Rodents for High Viability Tissue Collection The present protocol describes a standardized resection of brain tumors in rodents through a minimally invasive approach with an integrated tissue preservation system. This technique has implications for accurately mirroring the standard of care in rodent and other animal models. https://www.jove.com/v/64048 503 2022-05-09T21:00:00+00:00 JoVE no https://visualize.jove.com/42240861-educational-frameworks-for-diagnostic-decision-making-in-ai-enhanced-head-and-neck-pathology monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/66014.jpg Reliability of Artificial Intelligence-Based Cone Beam Computed Tomography Integration with Digital Dental Images A process of registering cone-beam computed tomography scans and digital dental images has been presented using artificial intelligence (AI) -assisted identification of landmarks and merging. A comparison with surface-based registration shows that AI-based digitization and integration are reliable and reproducible. https://www.jove.com/v/66014 349 2024-02-23T05:35:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/68270.jpg Introduction of an Integrated Pathology Image Management, Artificial Intelligence, and Reporting System Integrated image management, artificial intelligence (AI), and reporting systems have revolutionized diagnostic pathology practice. In this paper, we introduce FlexLIS, a state-of-the-art system that enables AI to assist pathologists in performing histopathology image assessments and generating diagnostic reports. https://www.jove.com/v/68270 333 2025-07-11T07:40:00+00:00 JoVE no https://visualize.jove.com/42255959-investigating-the-amyloid-tau-neurodegeneration-framework-in-alzheimers-disease-using-semi-supervised-multimodal-imaging-data-fusion monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/1988.jpg Basics of Multivariate Analysis in Neuroimaging Data The current article describes the basics of multivariate analysis and contrasts it to the more commonly used voxel-wise univariate analysis. Both types of analysis are applied to a clinical-neuroscience data set. Supplementary split-half simulations show better replication of the multivariate results in independent data sets. https://www.jove.com/v/1988 395 2010-07-24T09:00:00+00:00 JoVE no https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/15204.jpg Alzheimer's Disease: Overview Alzheimer's Disease (AD) is a continually advancing neurodegenerative disorder, distinguished by escalating memory loss, cognitive dysfunction, and dementia. The disease unfolds in three stages: preclinical, mild cognitive impairment (MCI), and dementia. Its onset is insidious, and the progression gradual, with the cause not well explained by other disorders. The clinical diagnosis of AD hinges on the presence of memory and other cognitive impairments. Biomarkers, such as changes in Aβ and tau... https://www.jove.com/v/15204 86 JoVE no https://cloudfront.jove.com/files/ftp_upload/40940/40940_article_thumb_40940.jpg Alzheimer Disease l: Introduction Alzheimer disease is a chronic, progressive, and irreversible neurodegenerative disorder and the most common cause of dementia in older adults. It leads to gradual neuronal loss, causing cognitive decline, behavioral changes, and loss of functional independence.Risk Factors and EtiologyThe disease is multifactorial. Age is the strongest risk factor, with prevalence doubling every 5 years after age 65. Genetic factors include mutations in genes such as APP, PSEN1, and PSEN2, which are associated... https://www.jove.com/v/40940 89 2026-04-15T17:31:37+00:00 JoVE no https://cloudfront.jove.com/files/ftp_upload/40941/40941_article_thumb_40941.jpg Alzheimer Disease ll: Pathophysiology Alzheimer disease involves structural changes in the brain that begin long before symptoms appear. The most distinctive features are extracellular neuritic plaques and intracellular neurofibrillary tangles.Neuritic plaques form in the cerebral cortex and around blood vessels. These plaques contain a dense core of beta-amyloid (Aβ)—a toxic protein fragment that clumps outside neurons. The core is surrounded by damaged neuronal extensions, as well as reactive astrocytes and microglia. Abnormal... https://www.jove.com/v/40941 83 2026-04-13T21:37:54+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/65910.jpg DeepOmicsAE: Representing Signaling Modules in Alzheimer's Disease with Deep Learning Analysis of Proteomics, Metabolomics, and Clinical Data DeepOmicsAE is a workflow centered on the application of a deep learning method (i.e., an autoencoder) to reduce the dimensionality of multi-omics data, providing a foundation for predictive models and signaling modules representing multiple layers of omics data. https://www.jove.com/v/65910 587 2023-12-15T06:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67574.jpg Hybrid PET/MRI Imaging of Alzheimer's Disease Based on 18 F-AV-1451 This protocol describes the use of 18F-AV-1451 PET/MRI to reveal tau pathology and neurodegeneration, aiding neurologists in diagnosing Alzheimer's disease, assessing its severity, and gaining insights into its progression and underlying pathological mechanisms. https://www.jove.com/v/67574 317 2025-04-18T05:00:00+00:00 JoVE no https://visualize.jove.com/42260570-enhance-autism-spectrum-disorder-detection-using-stacking-ensemble-learning-model-with-explainable-ai monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/65910.jpg DeepOmicsAE: Representing Signaling Modules in Alzheimer's Disease with Deep Learning Analysis of Proteomics, Metabolomics, and Clinical Data DeepOmicsAE is a workflow centered on the application of a deep learning method (i.e., an autoencoder) to reduce the dimensionality of multi-omics data, providing a foundation for predictive models and signaling modules representing multiple layers of omics data. https://www.jove.com/v/65910 587 2023-12-15T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67525.jpg Evidence-based Knowledge Synthesis and Hypothesis Validation: Navigating Biomedical Knowledge Bases via Explainable AI and Agentic Systems This article describes RUGGED (Retrieval Under Graph-Guided Explainable disease Distinction), which integrates Large Language Model (LLM) inference with Retrieval-Augmented Generation (RAG). It draws evidence from expert-curated biomedical knowledge bases and peer-reviewed biomedical publications to synthesize new knowledge from up-to-date information, identify explainable and actionable predictions, and pinpoint promising directions for hypothesis-driven investigations. https://www.jove.com/v/67525 347 2025-06-13T13:10:00+00:00 JoVE no https://visualize.jove.com/42264287-bias-external-validation-and-real-world-implementation-of-artificial-intelligence-models-in-cardiovascular-medicine monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/63573.jpg In Silico Clinical Trials for Cardiovascular Disease This protocol demonstrates the workflow of the SILICOFCM platform for automatically generating a parametric model of the left ventricle from patient-specific ultrasound images by applying a multi-scale electromechanical model of the heart. This platform enables in silico clinical trials intended to reduce real clinical trials and maximize positive therapeutic outcomes. https://www.jove.com/v/63573 549 2022-05-27T21:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/67674.jpg Assessing the Accuracy of Fitness Smartwatch Data for Cardiovascular and Physical Activity Monitoring: A Validation Study in Digital Health Wearable technology has low cost and offers convenient monitoring of physiological data. However, the accuracy and reliability of these devices require cautious assessment to ensure their effectiveness and safety for users. This report describes the validation process of a commercial smartwatch in monitoring physiological data and physical activity. https://www.jove.com/v/67674 351 2025-02-21T21:40:00+00:00 JoVE no https://visualize.jove.com/42285763-validation-of-artificial-intelligence-in-detecting-acute-cervical-spine-fractures-on-ct monthly 0.9 https://cloudfront.jove.com/CDNSource/teasers/3871.jpg Automated Midline Shift and Intracranial Pressure Estimation based on Brain CT Images An automated midline shift estimation and intracranial pressure (ICP) pre-screening system based on computed tomography (CT) images for patients with traumatic brain injury (TBI) is proposed using image processing and machine learning techniques. https://www.jove.com/v/3871 848 2013-04-13T14:00:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66014.jpg Reliability of Artificial Intelligence-Based Cone Beam Computed Tomography Integration with Digital Dental Images A process of registering cone-beam computed tomography scans and digital dental images has been presented using artificial intelligence (AI) -assisted identification of landmarks and merging. A comparison with surface-based registration shows that AI-based digitization and integration are reliable and reproducible. https://www.jove.com/v/66014 349 2024-02-23T13:35:00+00:00 JoVE no https://cloudfront.jove.com/CDNSource/teasers/66957.jpg Minimally Invasive Treatment for Thoracolumbar Burst Fracture Using Sagittal Alignment Screws and A Trauma Reduction Device The sagittal adjusting screw (SAS) system has been widely used for thoracolumbar (TL) spinal trauma. Percutaneous options and specialized trauma reduction devices are also available for the SAS system. We describe a technique for reducing TL burst fractures using an SAS system and a newly introduced trauma reduction device. https://www.jove.com/v/66957 259 2024-11-08T13:30:00+00:00 JoVE no