Related Experiment Video

Updated: Feb 1, 2026

Technique and Considerations in the Use of 4x1 Ring High-definition Transcranial Direct Current Stimulation HD-tDCS
15:05

Technique and Considerations in the Use of 4x1 Ring High-definition Transcranial Direct Current Stimulation HD-tDCS

Published on: July 14, 2013

38.5K

Observation of the geometric phase effect in the H + HD → H2 + D reaction

Daofu Yuan1, Yafu Guan2, Wentao Chen1

  • 1Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, 230026, China.

Science (New York, N.Y.)
|December 15, 2018
PubMed

More Related Videos

Real-time Observation of the DNA Strand Exchange Reaction Mediated by Rad5106:24

Real-time Observation of the DNA Strand Exchange Reaction Mediated by Rad51

Published on: February 13, 2019

8.6K
Author Spotlight: Visualizing Olfactory Receptor Expression in Mosquitoes06:32

Author Spotlight: Visualizing Olfactory Receptor Expression in Mosquitoes

Published on: November 17, 2023

2.0K

Related Concept Videos

Phase I Reactions: Hydrolytic Reactions01:15

Phase I Reactions: Hydrolytic Reactions

Hydrolysis, a cornerstone of phase I biotransformation reactions, uses water to cleave chemical bonds. This process is pivotal in drug metabolism, generating more polar metabolites that can be easily excreted.
An important hydrolytic reaction is ester hydrolysis. Ester bonds, often found in prodrugs, are broken down, increasing the solubility of drugs like aspirin and lidocaine for more straightforward elimination. Amide hydrolysis is another critical reaction, targeting amide bonds prevalent...
666
Phase II Reactions: Acetylation Reactions01:24

Phase II Reactions: Acetylation Reactions

Acetylation, a phase II biotransformation reaction, introduces an acetyl group to drugs or their metabolites. Acetyltransferase enzymes facilitate this reaction, which resembles α-amino acid conjugation due to the addition of a functional group to the drug molecule.
The substrates for acetylation are typically drugs or their metabolites with an amino, sulfonamide, or hydrazine functional group. Acetylation can occur at several points in the drug molecule, including primary, secondary, and...
813
Phase I Reactions: Reductive Reactions01:27

Phase I Reactions: Reductive Reactions

Phase I biotransformation reductive reactions are chemical processes that modify drugs by introducing or revealing polar functional groups via reduction. Enzymes called reductases catalyze these reactions, playing a pivotal role in drug metabolism by transforming lipophilic drugs into more polar, water-soluble metabolites for easy excretion. An essential type of reductive reaction is the carbonyl group reduction, where aldehydes and ketones are reduced to alcohols. An example is the...
595
Phase II Reactions: Methylation Reactions01:17

Phase II Reactions: Methylation Reactions

Methylation is a phase II biotransformation process involving the attachment of a methyl group to a substrate. Enzymes known as methyltransferases orchestrate this reaction.
The mechanism of methylation unfolds in two stages. The first stage sees a methyltransferase enzyme facilitating the transfer of a methyl group from S-adenosylmethionine (SAM) to the substrate, forming S-adenosylhomocysteine (SAH). The second stage involves further metabolism of SAH into homocysteine, which can be recycled...
728
Phase II Reactions: Miscellaneous Conjugation Reactions01:19

Phase II Reactions: Miscellaneous Conjugation Reactions

Phase II biotransformations are detoxification mechanisms that conjugate xenobiotics with endogenous substances, neutralizing their toxicity.
A key example involves the conjugation of cyanide ions, which impair cellular respiration and alter hemoglobin into non-oxygen-carrying cyanmethemoglobin. To neutralize this threat, a sulfur atom from thiosulphate is transferred to the cyanide ion, catalyzed by the enzyme rhodanese, resulting in an inactive compound called thiocyanate. The production of...
366
Geometric Mean01:15

Geometric Mean

The mean is a measure of the central tendency of a data set. In some data sets, the data is inherently multiplicative, and the arithmetic mean is not useful. For example, the human population multiplies with time, and so does the credit amount of financial investment, as the interest compounds over successive time intervals.
In cases of multiplicative data, the geometric mean is used for statistical analysis. First, the product of all the elements is taken. Then, if there are n elements in the...
4.0K