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941.
Hong Xia Yoshio Hashimoto Toru Morita Toshihiro Hirai 《Journal of Polymer Science.Polymer Physics》2014,52(13):887-892
Few solvents are capable of dissolving polyketones (PKs). 1,1,1,3,3,3‐Hexafluoro‐2‐propanol (hexafluoroisopropanol, HFIP) is a better solvent than trifluoroethanol and m‐cresol. When HFIP was evaporated from a PK/HFIP solution, a porous cast‐film with a microparticle structure was formed because the isotactic PKs adopted a helical conformation, and convection during evaporation of the high polarity and low‐boiling‐point HFIP caused aggregation and rolling of the polymer molecules. The addition of plasticizer suppressed particle formation, improving the surface structure and mechanical properties of the film. In particular, the dielectric properties of the film improved significantly. This will enable PKs, which are rigid insulating materials, to be used as dielectric materials, broadening their range of applications. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 887–892 相似文献
942.
Zhu Hong Zeng Xiangbing Han Tianli Li Xuexue Zhu Shuguang Sun Bai Zhou Ping Liu Jinyun 《Journal of Solid State Electrochemistry》2019,23(7):2173-2180
Journal of Solid State Electrochemistry - Since conventional graphite-based anode possesses a low capacity, seeking for high-capacity anode candidates becomes significant for constructing emerging... 相似文献
943.
Two coordination polymers, namely {[Co(L)(H2O)]·H2O}n(1) and [Mn(L)(phen)]n(2, H2L = 5-(pyridin-4-yl)isophthalic acid, phen = 1,10-phenanthroline), have been hydrothermally synthesized and characterized by elemental analysis, IR, TG, magnetic properties, and single-crystal X-ray diffraction. 1 belongs to the triclinic system, space group P1 with a = 7.2188(7), b = 10.0835(8), c = 10.2069(7) ?, α = 113.713(7), β = 99.490(7), γ = 104.516(8)o, V = 628.24(9) ?3, C13H11NCoO6, Mr = 336.16, Z = 2, Dc = 1.777 Mg/m3, μ(MoKα) = 1.395 mm–1, F(000) = 342, S = 1.041, the final R = 0.0381 and wR = 0.0819 for 3744 observed reflections(I 2σ(I)) and R = 0.0448 and wR = 0.0874 for all data. 2 belongs to the monoclinic system, space group P2/c with a = 12.9185(3), b = 10.4343(2), c = 31.7650(6)?, β = 101.282(2)o, V = 4199.08(13)?3, C50H30N6Mn2O8, Mr = 952.68, Z = 4, Dc = 1.507 Mg/m3, μ(MoKα) = 5.447 mm–1, F(000) = 1944, S = 1.128, the final R = 0.1003 and wR = 0.1052 for 8247 observed reflections(I 2σ(I)) and R = 0.2595 and wR = 0.2625 for all data. Single-crystal X-ray diffraction studies show that compound 1 features a 2D sheet structure based on a dicobalt(II) subunit, which is further extended into a 3D metal-organic supramolecular framework by O–H···O hydrogen bond. Compound 2 also possesses a 2D sheet, which is held together into a 3D supramolecular architecture via C–H···O hydrogen bond and π-π stacking interactions. Magnetic studies for compound 2 show antiferromagnetic coupling between the adjacent metal centers, with J = –11.8 cm–1 and g = 2.12 for 2. 相似文献
944.
945.
946.
947.
Analytical and Bioanalytical Chemistry - Abnormal concentration of hydrogen peroxide (H2O2) in blood plasma and cells may lead to several diseases. Thus, it is important to develop a selective and... 相似文献
948.
Non-small cell lung cancer (NSCLC) is a lethal non-immunogenic malignancy and proto-oncogene ROS-1 tyrosine kinase is one of its clinically relevant oncogenic markers. The ROS-1 inhibitor, crizotinib, demonstrated resistance due to the Gly2032Arg mutation. To curtail this resistance, researchers developed lorlatinib against the mutated kinase. In the present study, a receptor-ligand pharmacophore model exploiting the key features of lorlatinib binding with ROS-1 was exploited to identify inhibitors against the wild-type (WT) and the mutant (MT) kinase domain. The developed model was utilized to virtually screen the TimTec flavonoids database and the retrieved drug-like hits were subjected for docking with the WT and MT ROS-1 kinase. A total of 10 flavonoids displayed higher docking scores than lorlatinib. Subsequent molecular dynamics simulations of the acquired flavonoids with WT and MT ROS-1 revealed no steric clashes with the Arg2032 (MT ROS-1). The binding free energy calculations computed via molecular mechanics/Poisson-Boltzmann surface area (MM/PBSA) demonstrated one flavonoid (Hit) with better energy than lorlatinib in binding with WT and MT ROS-1. The Hit compound was observed to bind in the ROS-1 selectivity pocket comprised of residues from the β-3 sheet and DFG-motif. The identified Hit from this investigation could act as a potent WT and MT ROS-1 inhibitor. 相似文献
949.
A three-component hydrogen-bonded covalent organic polymer, namely JLUE-HCOP-66, was fabricated via a facile multiple-linking-site solvothermal approach to overcome the weakness of poor function complexity and limited structure diversity of the pure covalent skeletons. The as-prepared JLUE-HCOP-66 polymers were employed to decontaminate ciprofloxacin (CIP), a popular F-quinolones (FQNs) antibiotic, from water and exhibited satisfactory adsorption performance. Specifically, JLUE-HCOP-66 polymers have high adsorption capacity with the maximum contribution of 111.1 mg/g according to the Langmuir model, good antiinterference to NaCl salts, and excellent regeneration property. The pH-dependent experiment results signified the probably dominated mechanism of electrostatic interaction. In addition, adsorption studies and structural characterization in combination illustrated that the pore-filling effect, hydrogen bonding formation might also govern the whole process, accompanied by electrostatic interaction, dipole-dipole complexation, π-π EDA interaction, and hydrophobic-hydrophobic interaction besides. Moreover, electrostatic potentials, as well as the frontier molecular orbital distributions (HOMO and LUMO) of CIP and JLUE-HCOP-66 fragment, were calculated using density functional theory to theoretically support the research. Furthermore, the response surface methodology (RSM) according to the CCD matrix was used to not only study the interactive and cooperative effects of initial CIP concentration, initial pH, ionic strength along with JLUE-HCOP-66 dosage on CIP removal using JLUE-HCOP-66 but also optimize the operation conditions. Given the peculiar structure and functional feature, this work could hopefully bring HCOPs into the practical applications of such challenging and persistent ciprofloxacin potent removal with further large-scale efficiency. 相似文献
950.
Yujie Hua Xican Li Wenhui Zhang Ban Chen Yamei Liu Xiaojun Zhao Hong Xie Dongfeng Chen 《Journal of Saudi Chemical Society》2021,25(7):101272
Folium Hibisci Mutabilis, a new member of Chinese Pharmacopoeia, can treat some diseases induced by reactive oxygen species. The study prepared a lyophilized aqueous extract of Folium Hibisci Mutabilis (LAFHM). LAFHM was found to enrich eight flavonoids (i.e., quercetin, luteolin, hyperoside, isoquercitrin, rutin, kaempferol, tiliroside, and vitexin) by HPLC analysis. These flavonoids were further compared using antioxidant assays, where triliroside and vitexin always exhibited higher IC50 values than the others. In ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry analysis, these flavonoids could basically give two characteristic m/z values (226 and 196) and their corresponding double m/z values (i.e., 602, 570, 926, 926, 570, 1186, and 862), when treated by 1,1-diphenyl-2-picryl-hydrazl radical (DPPH?). Finally, the coupling products of DPPH?-treated triliroside were investigated using computational chemistry. It was found that the –OH in para-coumaroyl moiety to have the lowest bond disassociation energy among all phenolic -OHs in the triliroside. In conclusion, Folium Hibisci Mutabilis contains the above eight antioxidant flavonoids. Despite of the different antioxidant levels, they can generally produce flavonoid-radical coupling product and flavonoid-flavonoid homodimer during antioxidant process. Especially, tiliroside uses para-coumaroyl as linker to construct a tiliroside-radical coupling product at the meta-carbon atom. 相似文献