Broad Singlet
Broad Singlet - Related Videos
11:34
High-throughput Screening for Broad-spectrum Chemical Inhibitors of RNA Viruses
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Cited by 14 •
2014
In vitro assays to measure virus replication have been greatly improved by the development of recombinant RNA viruses expressing luciferase or other enzymes capable of bioluminescence. Here we detail a high-throughput screening pipeline that combines such recombinant strains of measles and chikungunya viruses to isolate broad-spectrum antivirals from chemical libraries.
![[(DPEPhos)(bcp)Cu]PF<sub>6</sub>: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg%3Fv%3D2026-09-01%252019%253A18%253A04&w=750&q=75)
09:12
[(DPEPhos)(bcp)Cu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst
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2019
Detailed and general protocols are presented for the synthesis of [(DPEPhos)(bcp)Cu]PF6, a general copper-based photoredox catalyst, and for its use in synthetic chemistry for the direct arylation of C-H bonds in (hetero)arenes and radical cyclization of organic halides.
09:23
Quantification of Information Encoded by Gene Expression Levels During Lifespan Modulation Under Broad-range Dietary Restriction in C. elegans
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Cited by 3 •
2017
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.
08:10
Multi-enzyme Screening Using a High-throughput Genetic Enzyme Screening System
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Cited by 7 •
2016
This work presents a method of high-throughput screening using a universal genetic enzyme screening system that can be theoretically applied to over 200 enzymes. Here, the single screening system identifies three different enzymes (lipase, cellulase, and alkaline phosphatase) by simply changing the substrate used (p-nitrophenyl acetate, p-nitrophenyl-β-D-cellobioside, and phenyl phosphate).
09:09
Single Nuclei Isolation from Coronary Endarterectomy Tissue of Coronary Artery Bypass Graft Patients
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2026
Coronary endarterectomy tissue samples were processed to isolate single nuclei using an optimized dissociation protocol. The integrity of the isolated nuclei was validated through three complementary approaches: trypan blue exclusion staining to assess membrane integrity, DAPI-based confocal microscopy to confirm nuclear morphology, and flow cytometry to quantify nuclear yield and purity.
FAQs
Rapid exchange between hydroxyl or amino protons and surrounding species can shorten the coherence time of the observed nuclei. This loss of coherence broadens the resonance and suppresses fine spin-spin structure that might otherwise be resolved. The resulting line shape can therefore indicate an exchangeable proton environment, although its exact appearance may depend on the local chemical surroundings.
Hydrogen bonding changes the environment experienced by hydroxyl or amino protons, influencing both their resonance position and the degree of line broadening. Exchange with traces of water or other protic species can produce additional changes, so the signal may not remain fixed in position or width. These effects help explain why exchangeable-proton signals can vary during analysis.
Coupling to quadrupolar nuclei can make fine splitting difficult to resolve, contributing to a broadened appearance. Conformational exchange can have a similar effect by changing the proton environment rapidly enough to blur distinct signal features. Recognizing either mechanism prevents analysts from interpreting every broadened, unsplit-looking resonance as evidence for the same functional group.
Its broadened, poorly resolved appearance provides a clue that the proton may belong to an exchangeable environment such as a hydroxyl or amino group rather than a nonexchangeable site with clearly observable coupling. Analysts use this distinction during chemical structure analysis, while also considering hydrogen bonding, protic impurities, conformational exchange, and quadrupolar coupling as possible contributors.
During compound identification, analysts evaluate the signal's width, position, and lack of resolved splitting together with the proposed molecular structure. A resonance with these characteristics can support assignment of an exchangeable proton and help assess its chemical environment. Because water or other protic species may alter the signal, the feature serves as structural evidence rather than an isolated identification criterion.
In reaction monitoring, changes in broadened proton signals can help researchers assess whether exchangeable functional-group environments are changing as the reaction proceeds. The observations may support assignment of reactants or products and reveal differences in molecular environments. Interpretation remains context-dependent because hydrogen bonding, exchange with protic species, conformational exchange, and coupling to quadrupolar nuclei can also influence the signal.