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71.
Iosif V. Gofman Ivan V. Abalov Svetlana V. Gladchenko Nadezhda V. Afanas'eva 《先进技术聚合物》2012,23(3):408-413
The mechanical characteristics and thermal properties of composite films based on the thermally stable aromatic polyimide (PI) (PMDA‐ODA) and carbon nanocones/discs (CNC) were studied. The introduction of CNC to PMDA‐ODA leads to the substantial increase of film stiffness. The Young's modulus values of the composite films are somewhat higher than those of the previously characterized composite films of this PI filled with nanoclay, carbon nanofibers, and asbestos‐like hydrosilicate nanotubes. The introduction of CNC into PMDA‐ODA (concentrations of CNC were up to 15 vol%) does not cause any marked aggregation of nanoparticles. The presence of CNC in the PI matrix does not affect the glass transition temperature of the polymer but hinders chain mobility at temperatures above Tg. This behavior makes it possible to increase the working temperature range of the composite films containing more than 5 vol% of CNCs, up to the temperature of thermal decomposition. The introduction of CNC into PMDA‐ODA leads to dramatic (~12 orders of magnitude) increase of active electrical conductivity of the material. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
72.
Alexander N. Titov Ingrid Bryntse Svetlana G. Titova Nadezhda V. Toporova 《Solid State Ionics》2001,140(3-4):293-300
The reaction between metallic Ag and PbS1.18(TiS2)n, n=1, 2, misfit layer compounds has been investigated by electrochemical technique, X-ray powder analysis and transmission electron microscopy. It was found that silver intercalation is possible only in the compound with n=2. The thermodynamic behavior and location of phase boundaries were studied in the temperature range 400–650 K. DC-conductivity and magnetic-susceptibility measurements were performed, and the data can be interpreted as an appearance of small polarons during silver insertion. 相似文献
73.
Alena L. Stalinskaya Nadezhda V. Martynenko Zarina T. Shulgau Alexandr V. Shustov Viktoriya V. Keyer Ivan V. Kulakov 《Molecules (Basel, Switzerland)》2022,27(12)
The COVID-19 pandemic is ongoing as of mid-2022 and requires the development of new therapeutic drugs, because the existing clinically approved drugs are limited. In this work, seven derivatives of epoxybenzooxocinopyridine were synthesized and tested for the ability to inhibit the replication of the SARS-CoV-2 virus in cell cultures. Among the described compounds, six were not able to suppress the SARS-CoV-2 virus’ replication. One compound, which is a derivative of epoxybenzooxocinopyridine with an attached side group of 3,4-dihydroquinoxalin-2-one, demonstrated antiviral activity comparable to that of one pharmaceutical drug. The described compound is a prospective lead substance, because the half-maximal effective concentration is 2.23 μg/μL, which is within a pharmacologically achievable range. 相似文献
74.
Lyubov G. Dezhenkova Anna A. Druzina Yulia L. Volodina Nadezhda V. Dudarova Natalia A. Nekrasova Olga B. Zhidkova Mikhail A. Grin Vladimir I. Bregadze 《Molecules (Basel, Switzerland)》2022,27(14)
A series of novel cobalt bis(dicarbollide)—curcumin conjugates were synthesized. Two conjugates were obtained through the nucleophilic ring-opening reaction of the 1,4-dioxane and tetrahydropyran derivatives of cobalt bis(dicarbollide) with the OH group of curcumin, and using two equiv. of the oxonium derivatives, two other conjugates containing two cobalt bis(dicarbollide) units per molecule were obtained. In contrast to curcumin, the conjugates obtained were found to be non-cytotoxic against both tumor and normal cell lines. The analysis of the intracellular accumulation of the conjugates by flow cytometry showed that all cobalt bis(dicarbollide)—curcumin conjugates entered HCT116 colorectal carcinoma cells in a time-dependent manner. New non-cytotoxic conjugates contain a large amount of boron atoms in the biomolecule and can potentially be used for further biological research into boron neutron capture therapy (BNCT). 相似文献
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Boris A. Trofimov Igor' A. Ushakov Alexander V. Vashchenko Nadezhda V. Zorina 《Tetrahedron letters》2004,45(19):3789-3791
Dioximes of hexane-2,5-dione and cyclohexane-1,4-dione react with acetylene in an autoclave (KOH/DMSO, 100 °C, 1 h, initial pressure 14 atm) to give 2,2′-dimethyl-1,1′-divinyl-[3,3′]bipyrrole and 1,5-divinyl-4,8-dihydropyrrolo[2,3-f]indole in 12% and 6% yields, respectively, thus exemplifying a very simple, straightforward route to inaccessible or unknown pyrrolic assemblies. 相似文献
78.
Rafael Doležal Natálie Karásková Karel Musil Martin Novák Nadezhda V. Maltsevskaya Dávid Maliňák 《Analytical letters》2018,51(15):2401-2414
The biological activity of drugs on organisms is associated with the pharmacokinetic properties, such as the ability to penetrate through environments of varying polarity such as cellular organelles. In this area, particular attention is turned to the physicochemical properties that determine the potential of drugs to pass across the blood–brain barrier and thus to act on the central nervous system. In this study, special effort has been devoted to the simulation of passive diffusion of seven drugs (propranolol, ibuprofen, atenolol, promazine, chlorpromazine, imipramine, and desipramine) through the blood–brain barrier by high-performance liquid chromatography (HPLC) using a column with an immobilized artificial membrane. Gradient reverse elution was used to develop a linear correlation model for the capacity factors kIAM and the in vivo logarithmic values of brain-to-blood drug concentration ratios (log BB) with R of 0.9851. Eleven additional pharmaceuticals were determined by the same method to predict their potential to penetrate the blood–brain barrier. The reported analytical method represents an alternative tool for rapid and noninvasive assessment of the absorption properties of chemicals, especially for the development of novel drugs. The retention of the studied compounds on the immobilized artificial membrane column was also compared with three other C18-based stationary phases. Herein, the results of the HPLC determination of drugs using an immobilized artificial membrane are briefly discussed with respect to a general application of the method for evaluating a broader spectrum of pharmaceutical compounds. 相似文献
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The new alkaloid 6alpha-angeloylplatynecine, together with other four known pyrrolizidine alkaloids was identified from above ground parts of Senecio nemorensis subs. fuchsii. 相似文献