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561.
Possibility of obtaining mesoporous silicon dioxide antireflection coatings with low refractive index (1.20–1.277) by using additions of poly(propylene glycols) with various molecular masses in a sol-gel process was examined. It was demonstrated that the optimal concentration of poly(propylene glycols) in the sol, at which a sol-gel process followed by heating of a sample yields a transparent film with a maximum light transmission of 98.3–99.0%, depends on the average molecular mass of the additive.  相似文献   
562.
Microtubule targeting agents (MTAs) that interfere with the dynamic state of the mitotic spindle are well-known and effective chemotherapeutic agents. These agents interrupt the microtubule network via polymerization or depolymerization, halting the cell cycle progression and leading to apoptosis. We report two novel pyrrole-based carboxamides (CAs) (CA-61 and -84) as the compounds exhibiting potent anti-cancer properties against a broad spectrum of epithelial cancer cell lines, including breast, lung, and prostate cancer. The anti-cancer activity of CAs is due to their ability to interfere with the microtubules network and inhibit tubulin polymerization. Molecular docking demonstrated an efficient binding between these ligands and the colchicine-binding site on the tubulin. CA-61 formed two hydrogen bond interactions with THR 179 (B) and THR 353 (B), whereas two hydrogen bonds with LYS 254 (B) and 1 with ASN 101 (A) were identified for CA-84. The binding energy for CA-84 and CA-61 was −9.910 kcal/mol and −9.390 kcal/mol. A tubulin polymerization assay revealed a strong inhibition of tubulin polymerization induced by CA-61 and -84. The immunofluorescence data revealed the disruption of the tubulin assembly in CA-treated cancer cells. As an outcome of the tubulin inhibition, these compounds halted the cell cycle progression in the G2/M phase, leading to the accumulation of the mitotic cells, and further induced apoptosis. Lastly, the in vivo study indicated that CAs significantly inhibited the HCC1806 breast cancer xenograft tumor growth in a nude mouse model. Collectively, we identified the novel CAs as potent MTAs, inhibiting tubulin polymerization via binding to the colchicine-binding site, disrupting the microtubule network, and exhibiting potent pro-apoptotic activities against the epithelial cancer cell lines both in vitro and in vivo.  相似文献   
563.
The structure of the trigonal modification of Cs3Sb2I9was refined by XRD methods (Syntex {ie572-1} diffractometer, λMoKα at T = 285 K. The structure is ofperovskite type A3B3-xX9 with ordered vacancies in the B-sublattice. The unit cell with pseudo-R-centering has the following parameters: α = 8.435(7), c = 10.390(7) Å, V = 757.5 Å3, Z = 1; dx = 4.67 g/cm3. The centrosymmetric space group {ie572-2} was chosen based on the laser radiation second harmonic generation test. The parameters of the pseudo-rhombohedron corresponding to the perovskite cell are a’ = 5.976 å, α = 89.78°. The R-lattice of a perovskite structure is disturbed by ordered Sb vacancies in one of the three I6, octahedra. The structural modifications of the compounds A3B2X9 are analyzed in terms of Dornberger-Schiffs OD theory as the members of the family formed by the two-dimensional periodic fragments ofperovskite type structures.  相似文献   
564.
Crystal adducts of diethyldithiocarbamate complexes of zinc(II) and copper(II) with piperidine (Pip) were synthesized, and their solvated forms with the outer-sphere molecules of benzene, pyridine (Py), and morpholine (Mf) were obtained. Adducts with composition [M(Pip)(Edtc)2] · L (L = Py, Mf) were shown to be able, in principle, to give solvated isomers [M(L)(Edtc)2] · Pip with the Pip molecule arranged in the outer sphere. The composition, structure, and properties of the obtained adducts were studied by EPR, high-resolution solid-state 13C, 15N NMR spectroscopy. Solvation of all three adducts with Pip, Mf, and Py was found to result in a substantial increase in the contribution of the trigonal–bipyramidal component to the geometry of a copper coordination pentahedron. In addition, for adducts with Mf and Py, a structural unification of two isomeric forms was observed at the molecular level to yield a qualitatively new (rather than intermediate) state. It was shown that in all solvated forms of the copper(II) adducts, the metal polyhedron is mainly a trigonal bipyramid, while the square–pyramidal contribution is insignificant. Results of (13C, 15N) NMR studies revealed a structural inequivalence of the Edtcligands in the zinc adducts under investigation.  相似文献   
565.
Conclusions In the reaction of 3,6-di-tert-butyl-o-benzoquinone with acids in different media, the protonated form of the quinone can exhibit the properties of an oxidizing agent or an electrophile, depending on the nature of the acid and solvent.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2110–2113, September, 1981.  相似文献   
566.
567.
Conclusions Study has been made of the kinetics of the reaction of p-nitrophenylbis(chloromethyl)-phosphinate with primary and secondary amines. Reaction proceeds through rupture of the ester bond at the P atom and is catalyzed by a second amine molecule. The reaction rate is determined by induction and steric effects in the amine substituents. The activation energy for the reaction with n-butylamine is negative.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1292–1295, June, 1977.  相似文献   
568.
569.
The ionic composition of a cation-exchange membrane in solutions of amino acids of three types is studied by measuring its conductivity. The concentration constants of equilibrium of the protonation of zwitterions of these acids in the membrane are estimated. The membrane's ionic composition substantially depends on the type of amino acid.  相似文献   
570.
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