Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

¹³C NMR: ¹H–¹³C Decoupling01:04

¹³C NMR: ¹H–¹³C Decoupling

1.8K
The probability of having two carbon-13 atoms next to each other is negligible because of the low natural abundance of carbon-13. Consequently, peak splitting due to carbon-carbon spin-spin coupling is not observed in spectra. However, protons up to three sigma bonds away split the carbon signal according to the n+1 rule, resulting in complicated spectra.
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
1.8K
Fast Decoupled and DC Powerflow01:24

Fast Decoupled and DC Powerflow

756
The fast decoupled power flow method addresses contingencies in power system operations, such as generator outages or transmission line failures. This method provides quick power flow solutions, essential for real-time system adjustments. Fast decoupled power flow algorithms simplify the Jacobian matrix by neglecting certain elements, leading to two sets of decoupled equations:
756
Sign Convention01:30

Sign Convention

3.5K
When analyzing a beam subjected to various loads, it is crucial to understand the internal forces and moments generated within the structure. These internal forces can be broadly classified into normal forces, shear forces, and bending moments. To determine these forces and moments, we use the method of sections and apply a specific sign convention based on their direction and the side of the section being analyzed.
The normal force acts perpendicular to the beam's cross-section and can...
3.5K
Impedance Combination01:21

Impedance Combination

753
Consider a string of christmas lights, each bulb symbolizing an impedance element. In this series configuration, the flow of electric current remains uniform across every component. This behavior aligns with Kirchhoff's Voltage Law (KVL), which asserts that the total impedance in such a setup equals the sum of individual impedances—akin to resistors in series. It follows that the voltage from the power source is distributed proportionally among these components, adhering to the voltage...
753
Impedances and Admittance01:23

Impedances and Admittance

1.9K
In the realm of AC circuits, passive circuit elements like resistors, inductors, and capacitors take on a different character when characterized by phasor voltage and current. Their behavior is expressed through impedance, a vital concept in AC circuit analysis.
Impedance is a measure of resistance to sinusoidal current flow in an AC circuit. Unlike their behavior in DC circuits, where inductors appear as short circuits and capacitors as open circuits, the behavior of these components in AC...
1.9K
Frequency-dependent Selection01:21

Frequency-dependent Selection

24.1K
When the fitness of a trait is influenced by how common it is (i.e., its frequency) relative to different traits within a population, this is referred to as frequency-dependent selection. Frequency-dependent selection may occur between species or within a single species. This type of selection can either be positive—with more common phenotypes having higher fitness—or negative, with rarer phenotypes conferring increased fitness.
24.1K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Imaging post-reperfusion metabolism in porcine myocardial infarction with hyperpolarized <sup>13</sup>C pyruvate MRI.

Journal of cardiovascular magnetic resonance : official journal of the Society for Cardiovascular Magnetic Resonance·2026
Same author

Hyperpolarized MRI Detects Increased [1-<sup>13</sup>C]Pyruvate Metabolism in Early Liver Regeneration.

NMR in biomedicine·2026
Same author

Complementary hyperpolarized <sup>13</sup>C and <sup>15</sup>N MRI reveal divergent signatures of hepatic injury and methyl-donor metabolism.

Npj imaging·2026
Same author

Atlas of Brain Glucose Metabolism Using Deuterium Metabolic Imaging at 3 T.

Magnetic resonance in medicine·2026
Same author

Association of brain structure and motor function in older persons with multiple sclerosis and healthy controls: A cross-sectional study.

Multiple sclerosis and related disorders·2026
Same author

Signal-to-noise ratio comparison of k-space sampling schemes for sodium MRI of the brain at 3 T.

Magma (New York, N.Y.)·2026

Related Experiment Video

Updated: Feb 2, 2026

Chemical Reversion of Conventional Human Pluripotent Stem Cells to a Na&#239;ve-like State with Improved Multilineage Differentiation Potency
09:07

Chemical Reversion of Conventional Human Pluripotent Stem Cells to a Naïve-like State with Improved Multilineage Differentiation Potency

Published on: June 10, 2018

10.6K

Improved Decoupling for Low Frequency MRI Arrays using Non-conventional Preamplifier Impedance.

Juan D Sanchez-Heredia, Daniel H Johansen, Rie B Hansen

    IEEE Transactions on Bio-Medical Engineering
    |November 17, 2018
    PubMed
    Summary

    This study introduces a new method to enhance preamplifier decoupling in low-frequency MRI coil arrays. The technique significantly boosts signal-to-noise ratio (SNR) for improved imaging, especially in low-sample-loading scenarios.

    More Related Videos

    Noninvasive In Vivo Small Animal MRI and MRS: Basic Experimental Procedures
    12:27

    Noninvasive In Vivo Small Animal MRI and MRS: Basic Experimental Procedures

    Published on: October 20, 2009

    16.7K
    A High Performance Impedance-based Platform for Evaporation Rate Detection
    06:39

    A High Performance Impedance-based Platform for Evaporation Rate Detection

    Published on: October 17, 2016

    6.9K

    Related Experiment Videos

    Last Updated: Feb 2, 2026

    Chemical Reversion of Conventional Human Pluripotent Stem Cells to a Na&#239;ve-like State with Improved Multilineage Differentiation Potency
    09:07

    Chemical Reversion of Conventional Human Pluripotent Stem Cells to a Naïve-like State with Improved Multilineage Differentiation Potency

    Published on: June 10, 2018

    10.6K
    Noninvasive In Vivo Small Animal MRI and MRS: Basic Experimental Procedures
    12:27

    Noninvasive In Vivo Small Animal MRI and MRS: Basic Experimental Procedures

    Published on: October 20, 2009

    16.7K
    A High Performance Impedance-based Platform for Evaporation Rate Detection
    06:39

    A High Performance Impedance-based Platform for Evaporation Rate Detection

    Published on: October 17, 2016

    6.9K

    Area of Science:

    • Magnetic Resonance Imaging (MRI)
    • Radiofrequency (RF) Engineering
    • Coil Array Design

    Background:

    • Low-frequency MRI receive coil arrays often suffer from poor preamplifier decoupling.
    • Low sample loading and high coil Q-factors exacerbate coupling issues, degrading Signal-to-Noise Ratio (SNR).
    • Traditional coil designs face limitations in achieving optimal decoupling without compromising geometry.

    Purpose of the Study:

    • To present a novel method for improving preamplifier decoupling in low-frequency MRI receive coil arrays.
    • To demonstrate enhanced SNR and parallel imaging performance through optimized coil design.
    • To address SNR degradation caused by coil coupling in low-loading environments.

    Main Methods:

    • Matching coils to an impedance higher than 50 Ω to achieve superior decoupling.
    • Utilizing preamplifiers with inductive, low-resistive input impedance to further boost decoupling effectiveness.
    • Designing an 8-channel 13C array for human head imaging at 32 MHz based on the proposed strategy.

    Main Results:

    • The developed strategy significantly reduces SNR degradation from coil coupling.
    • An 8-channel 13C array was successfully built without overlapping elements, enabling better spatial encoding.
    • The new array design demonstrated nearly a 2-fold SNR enhancement compared to traditional arrays.

    Conclusions:

    • The proposed coil array design strategy is highly beneficial for low-frequency MRI where coil thermal noise is dominant.
    • This method effectively mitigates noise correlation issues arising from insufficient coil decoupling in low-loading arrays.
    • The demonstrated 8-channel 13C array at 3T (32 MHz) validates the practical application and significant SNR improvement potential.