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951.
V. Yu. Gus’kov S. P. Ivanov Yu. F. Shaikhitdinova F. Kh. Kudasheva 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2016,90(10):2006-2010
Thermodynamic characteristics of the adsorption of alkanes, alcohols, arenes, and esters on graphitized carbon black with a deposited monolayer (0.17%) of 5-hydroxy-6-methyluracil are studied by means of inverse gas chromatography at infinite dilution. It is established that size effects (violation of the additivity of molar changes in internal energy and the entropy of adsorption for pairs of molecules of one homologous series that differ by one methyl group) are observed when organic molecules are adsorbed on the surface of the resulting adsorbent. The size effects are similar to those observed when 1% 5-hydroxy-6-methyluracil is deposited on graphitized carbon black. It is concluded that the observed violation of additivity is associated with cavities in the supramolecular structure. 相似文献
952.
Zuzana Vanovčanová Pavol Alexy Jozef Feranc Roderik Plavec Ján Bočkaj Leona Kaliňáková Katarína Tomanová Dagmara Perd’ochová Dávid Šariský Ivana Gálisová 《Chemical Papers》2016,70(10):1408-1415
Blends of biodegradable polymers polylactic acid/thermoplastic starch/polyhydroxybutyrate (PLA/TPS/PHB) were prepared using a twin-screw extruder. The TPS content was constant (50 %) and the PHB content in the blends was gradually changed from 0 mass % to 20 mass %. TPS was prepared by melting, where a mixture of native starch, water and glycerol was fed into the twinscrew extruder. Average temperature of extrusion was 180°C and the concentration of glycerol was 40 mass %. Influence of the PHB concentration in the blend and that of the processing technology on the mechanical and rheological properties of the PLA/PHB composition containing TPS were studied. Mechanical properties were measured 24 h after the film and monofilament preparation and also after the specific storage time to study the effect of storage on the properties. The results indicate that differences in morphology strongly influence the mechanical properties of the studied materials with identical material composition. 相似文献
953.
Alkyl glycosides as potential anti-<Emphasis Type="Italic">Candida albicans</Emphasis> growth agents
Tomáš Klunda Eva Machová Alžzbeta Čížzová Radim Horák Monika Poláková Slavomír Bystrický 《Chemical Papers》2016,70(9):1166-1170
Candida infections are becoming increasingly prevalent and many clinical isolates are resistant to common azole derivatives treatment. Accordingly, the capacity of a series of 19 alkyl glycosides, mainly mannosides and glucosides but also a cellobioside with aglycone chain-length from C-6 to C-20, to inhibit the growth of laboratory and clinically isolated strains of Candida albicans, was investigated. The study showed that only glycosides with the C-10 and C-12 aglycones were effective growth inhibitors of both types of Candida, strains, whose metabolic activity was also significantly reduced as revealed by an XTT assay. 相似文献
954.
This work presents a study on asphalt mixtures prepared with different kinds of additives: poly(styrene-co-butadiene-co-styrene), poly(ethylene-co-vinyl acetate), crumb rubber, fibers, zeolites and clays. The aim of this study was to determine the influence of inorganic dirt and fibers present in crumb rubber on the qualitative parameters of asphalt mixtures. The experiments showed that dynamic viscosity is the best criterion for assessing the effectiveness of the additives in asphalt mixtures. It was also found that fibers and inorganic impurities present in crumb rubber at low concentrations have a negligible effect on the characteristics of asphalt mixtures. This investigation is important in terms of determining the degree of crumb rubber devulcanization in crumb rubber-asphalt mixtures as higher crumb rubber devulcanization could bring the properties of such a mixture closer to those of asphalts modified by poly(styrene-co-butadiene-co-styrene) copolymers. 相似文献
955.
956.
M. N. Gorbunova G. F. Krainova D. M. Kisel’kov V. O. Nebogatikov 《Russian Journal of Applied Chemistry》2016,89(3):439-446
New biologically active silver nanocomposites based on the copolymer of lup-20(29)-ene-3,28-diol 28-O-vinylbenzoate with N-vinylpyrrolidone were prepared by the borohydride method. The formation of spherical nanoparticles with a mean diameter of 67 nm was confirmed by scanning electron microscopy. The synthesized copolymers and silver nanocomposites exhibit cytotoxic activity and show promise for the development of new materials for medical purposes. 相似文献
957.
I. N. Stan’kov V. B. Kondrat’ev I. D. Derevyagina O. T. Morozova V. I. Selivanova F. M. Semchenko K. A. Rufanov S. I. Dvoretskaya 《Journal of Analytical Chemistry》2016,71(3):289-296
A method has been developed for the determination of tetrodotoxin in water, blood plasma, and drugs at a level of 0.05—1.0 µg/mL. The method is based on the hydrolytic decomposition of tetrodotoxin by a sodium hydroxide solution, extraction of 2-amino-6-hydroxymethyl-8-hydroxyquinazoline using liquid–liquid extraction, preparation of its derivative by reaction with N,O-bis(trimethylsilyl)trifluroacetamide, and the determination of the derivative by gas–liquid chromatography with a mass-spectrometric detector. 相似文献
958.
The stability (affinity, association, binding, complexation, formation) constant characterizes binding interaction between the analyte and the complexing agent. Knowledge of the stability constant makes possible the prediction and estimation of the binding behavior of constituents (amino acids, peptides, proteins, drugs, antibiotics, enzymes, enantiomers) to their partners, and the finding of a suitable partner for the given analyte to form a stable complex. The present paper summarizes the stability constant determination methods and the approaches used to evaluate the experimental data. Further, the paper recapitulates the published stability constant values determined, mainly, by capillary electrophoretic methods, taken from the Web of Science database covering the last decade. Details of the experimental conditions employed for the determination of the stability constants are also given. The review attempts to give a critical evaluation of the problems that accompany the determination of stability constant and discusses their solution. 相似文献
959.
The depository effects that occur in slowly metabolized proteins (typically glycation) are very difficult to assess, owing to their extremely low concentration in the protein matrix. Collagen accumulates reactive metabolites through reactions that are not regulated by enzymes. A typical example of these non-enzymatic changes is glycation (the Maillard reaction, the formation of advanced glycation end products), resulting from the reaction of the oxo-group of sugars with the epsilon-amino group of lysine and arginine. Collagen samples (type I) as a test protein were incubated separately with glucose, ribose and malondialdehyde. Collagen was fragmented with cyanogen bromide and then digested with trypsin. This peptide digest was separated by CE, CE-MS/MS, and HPLC-MS/MS. An ion trap MS was used and MS conditions were optimized for both methods. These on-line CE-MS/MS and HPLC-MS/MS couplings made it possible to discover specific modifications such as (N(epsilon)-(carboxymethyl)-lysine) in the precise location in the structure of collagen corresponding to posttranslational non-enzymatic modifications. A new CE-MS/MS technique for peptide analysis was developed, and applied in the identification of posttranslational modifications in slowly metabolized test proteins. 相似文献
960.
Vida Július Ilčíková Martina Přibyl Roman Homola Tomáš 《Plasma Chemistry and Plasma Processing》2021,41(3):841-854
Plasma Chemistry and Plasma Processing - Activation of polymeric surfaces, i.e. formation and/or modification of the functional groups on the surface of a material, is essential prior to the... 相似文献