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521.
Yulia Shulpekova Maria Zharkova Pyotr Tkachenko Igor Tikhonov Alexander Stepanov Alexandra Synitsyna Alexander Izotov Tatyana Butkova Nadezhda Shulpekova Natalia Lapina Vladimir Nechaev Svetlana Kardasheva Alexey Okhlobystin Vladimir Ivashkin 《Molecules (Basel, Switzerland)》2022,27(11)
Bile acids are specific and quantitatively important organic components of bile, which are synthesized by hepatocytes from cholesterol and are involved in the osmotic process that ensures the outflow of bile. Bile acids include many varieties of amphipathic acid steroids. These are molecules that play a major role in the digestion of fats and the intestinal absorption of hydrophobic compounds and are also involved in the regulation of many functions of the liver, cholangiocytes, and extrahepatic tissues, acting essentially as hormones. The biological effects are realized through variable membrane or nuclear receptors. Hepatic synthesis, intestinal modifications, intestinal peristalsis and permeability, and receptor activity can affect the quantitative and qualitative bile acids composition significantly leading to extrahepatic pathologies. The complexity of bile acids receptors and the effects of cross-activations makes interpretation of the results of the studies rather difficult. In spite, this is a very perspective direction for pharmacology. 相似文献
522.
Alexander M. Wasserman Mikhail V. Motyakin Larisa L. Yasina Yulia A. Zakharova Vladimir N. Matveenko Yulia V. Shulevich Lidia Z. Rogovina 《Applied magnetic resonance》2010,38(1):117-135
Molecular dynamics, structure, and phase state of two new micellar systems were investigated using spin-probe electron paramagnetic
resonance spectroscopy. While the local mobility of the new cationic long-chain detergents varies in micelles in a minor way
when the length of a chain increases from 16 to 22 carbon atoms, the order parameter increases noticeably. The latter is caused
by gain of hydrophobic interactions. It is worthwhile to note that the incorporation of the two hydroxyl groups into the polar
head group of the C22 detergent influences particularly on the molecular dynamics and phase state of an aqueous solution of
the detergent. Furthermore, not only the local mobility decreases and ordering factor increases, but also the phase state
of the system changes, being transited from the solid to the micellar (liquid) state. Addition of the KCl salt in an aqueous
solution of the long-chain detergents results in a decrease of local mobility and increase of ordering factor. The phase transitions
are found to be caused by the addition of the salt. The cationic monomer [2-(methacryloyloxy)ethyl]trimethylammonium methyl
sulfate was shown to decrease the critical concentration of micelle formation of the anionic detergent sodium dodecyl sulfate
(SDS). Most likely this is because, being the counterion, the cationic monomer forms a dense layer around the SDS micelle.
Binding of SDS micelle with the monomer strongly reduces the local mobility of the detergent. 相似文献
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526.
Yulia S. Fetisova Oksana A. Dudarko Maja Bauman Aleksandra Lobnik Valeriia V. Sliesarenko 《Journal of Sol-Gel Science and Technology》2018,85(1):66-75
The mesoporous silica samples with different concentrations of phosphonic acid groups on the surface were obtained by direct template synthesis. The block-copolymer Pluronic P123 was used as a template, and sodium meta-silicate with diethylphosphatoethyltriethoxysilane as precursors. According to the SAXS diffractograms, mesoporous silica samples have a p6mm hexagonal symmetry. In addition, we used sol–gel method to synthesize xerogel with the same groups for comparison. All samples possess high values of specific surface area 615–730?m2/g and sorption pore volume. FTIR and potentiometric titration methods were used to investigate the surface layer of these samples. Sorption properties of the samples with phosphonic acid groups were studied in respect to a row of metal cations, among which we focused on lead(II), cadmium(II), and dysprosium(III) cations. 相似文献
527.
Yulia G. Budnikova Oleg G. Sinyashin Tatyana P. Gryaznova Mikhail P. Egorov 《Journal of organometallic chemistry》2007,692(19):4067-4072
Convenient synthetic route to prepare the germylene complexes of tungsten pentacarbonyls, W(CO)5GeCl2 and W(CO)5GeW(CO)5, electrochemically is developed. Combined quantum-chemical/IR spectroscopic approach is used for identification of the synthesized compounds. Good agreement between theoretical and experimental spectra can be regarded as one of the proofs of their supposed structures. 相似文献
528.
Yulia M. Sadykova Natalia V. Dalmatova Milyausha F. Nagimova Yulia K. Voronina Alexander R. Burilov Michael A. Pudovik leg G. Sinyashin 《Heteroatom Chemistry》2014,25(1):55-59
Condensation of naphthol‐1 and naphthol‐2 with 2‐ethoxyvinyphosphonic acid dichloroanhydride in boiling toluene in the presence of trifluoroacetic acid has resulted in high yields of unknown bicyclic phosphonates. Composition and structure of the products obtained were confirmed according to 1H and 31P nuclear magnetic resonance, infrared spectroscopy, and X‐ray analysis. 相似文献
529.
A. K. Abramyan N. M. Bessonov D. A. Indeitsev Yu. A. Mochalova B. N. Semenov 《Vestnik St. Petersburg University: Mathematics》2011,44(1):5-12
In modern constructions, thin-layer coats are often used as protecting or strengthening elements. Deformations of such constructions may cause significant stresses on the interface between the base and the coat because of the difference in their physical-mechanical properties, which leads to the destruction or detachment of the cover. Of special interest is strength analysis under dynamical or vibrational impacts because of the possibility of localizing oscillations in a neighborhood of the initial inhomogeneities (such as inclusions, defects, construction elements, etc.). In this paper, on the example of the detachment of a string from an elastic substrate, the possibility of localizing oscillations on a detachment defect is demonstrated and the effect of this localization on the growth of the detachment zone is analyzed. A simplified setting of the problem is considered. The possibility of localizing oscillations on a detachment defect is demonstrated and an approximate analytical solution is constructed, which takes into account only the first symmetric form of oscillations describing the development of the initial detachment. A numerical modeling of the problem is performed, and the results of modeling are compared with the approximate analytical solution. 相似文献
530.