14,618 research outputs found

    2-[(2-Carboxy­phen­yl)sulfan­yl]acetic acid

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    The title compound, C9H8O4S, affords a zigzig chain in the crystal structure by inter­molecular O—H⋯O hydrogen bonds. The molecular geometry suggests that extensive but not uniform π-electron delocalization is present in the benzene ring and extends over the exocyclic C—S and C—C bonds

    Engineering Test Research of XPS Insulation Structure Applied in High Speed Railway of Seasonal Frozen Soil Roadbed

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    AbstractDynamic performance and thermal properties of insulation materials are the key parameters during the insulation application for high-speed railway subgrade. This paper conducted field tests and field monitoring for the materials, especially for thermal performance, elastic deformation, and accumulated deformation of insulation materials. Experiment results show that mechanical properties of full section insulation layer structure is stable, which satisfies the requirements of the high speed railway

    (4-Bromo-2-{[2-(morpholin-4-yl)ethyl­imino]­meth­yl}phenolato)dioxido­vanadium(V)

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    In the title mononuclear dioxidovanadium(V) complex, [V(C13H16BrN2O2)O2], the VV atom is five-coordinated by one phenolate O, one imine N and one morpholine N atom of the Schiff base ligand, and by two oxide O atoms, forming a distorted square-pyramidal geometry. In the crystal, weak C—H⋯O inter­actions and a short Br⋯Br contact [3.4597 (12) Å] are observed

    Purification and characterization of Aspergillus niger α-L-rhamnosidase for the biotransformation of naringin to prunin

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    This study was conducted to increase the bioactivity of litchi pericarp polysaccharides (LPPs) biotransformed by Aspergillus awamori. Comparedtothenon-A. awamori-fermented LPP, the growth effects of A. awamori-fermented LPP on Lactobacillus bulgaricus and Streptococcus thermophilus were four and two times higher after 3 days of fermentation, respectively. Increased 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and DNA protection activity of litchi pericarp polysaccharides were also achieved after A. awamori fermentation. Moreover, the relative content of glucose and arabinose in LPP after fermentation decreased from 58.82% to 22.60% and from 18.82% to 10.09%, respectively, with a concomitant increase in the relative contents of galactose, rhamnose, xylose, and mannose. Furthermore, lower molecular weight polysaccharides were obtained after A. awamori fermentation. It can be concluded that A. awamori was effective in biotransforming LPP into a bioactive mixture with lower molecular weight polysaccharides and higher antioxidant activity and relative galactose content

    Predicting the network of substrate-enzyme-product triads by combining compound similarity and functional domain composition

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    <p>Abstract</p> <p>Background</p> <p>Metabolic pathway is a highly regulated network consisting of many metabolic reactions involving substrates, enzymes, and products, where substrates can be transformed into products with particular catalytic enzymes. Since experimental determination of the network of substrate-enzyme-product triad (whether the substrate can be transformed into the product with a given enzyme) is both time-consuming and expensive, it would be very useful to develop a computational approach for predicting the network of substrate-enzyme-product triads.</p> <p>Results</p> <p>A mathematical model for predicting the network of substrate-enzyme-product triads was developed. Meanwhile, a benchmark dataset was constructed that contains 744,192 substrate-enzyme-product triads, of which 14,592 are networking triads, and 729,600 are non-networking triads; i.e., the number of the negative triads was about 50 times the number of the positive triads. The molecular graph was introduced to calculate the similarity between the substrate compounds and between the product compounds, while the functional domain composition was introduced to calculate the similarity between enzyme molecules. The nearest neighbour algorithm was utilized as a prediction engine, in which a novel metric was introduced to measure the "nearness" between triads. To train and test the prediction engine, one tenth of the positive triads and one tenth of the negative triads were randomly picked from the benchmark dataset as the testing samples, while the remaining were used to train the prediction model. It was observed that the overall success rate in predicting the network for the testing samples was 98.71%, with 95.41% success rate for the 1,460 testing networking triads and 98.77% for the 72,960 testing non-networking triads.</p> <p>Conclusions</p> <p>It is quite promising and encouraged to use the molecular graph to calculate the similarity between compounds and use the functional domain composition to calculate the similarity between enzymes for studying the substrate-enzyme-product network system. The software is available upon request.</p

    Supersymmetric Extension of the Minimal Dark Matter Model

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    The minimal dark matter model is given a supersymmetric extension. A super SU(2)L quintuplet is introduced with its fermionic neutral component still being the dark matter, the dark matter particle mass is about 19.7 GeV. Mass splitting among the quintplet due to supersymmetry particles is found to be negligibly small compared to the electroweak corrections. Other properties of this supersymmetry model are studied, it has the solutions to the PAMELA and Fermi-LAT anomaly, the predictions in higher energies need further experimental data to verify.Comment: 14 pages, 7 figures, accepted for publication in Chinese Physics C, typos correcte
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