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排序方式: 共有208条查询结果,搜索用时 15 毫秒
131.
Ikumi Sugiyama Saki Kojima Naoto Oku Yasuyuki Sadzuka 《Colloid and polymer science》2010,288(12-13):1293-1300
It has been shown that lifestyle-related diseases and aging are related to reactive oxygen species (ROS), and many studies have reported on the direct detection of ROS. The topical fluorescence reagent 2,7-dichlorodihydrofluorescein (DCDHF) is used to measure oxidation. However, there are problems regarding its stability, and its similar sensitivity to ROS cannot be easily distinguished. In this study, we used hydroxyphenyl fluorescein (HPF), which is a novel fluorescence probe with high stability against light that undergoes specific reactions with highly ROS (hROS). We examined the specificity for hROS of HPF solution and liposomal HPF in different reactions. HPF containing high cholesterol liposomes (HC-H-lipo) maintained its ability to tolerate light scattering energy, dependent on the turbidity of this solution, but DCDHF did not. In the reaction with hydroxyl radicals, the fluorescein concentration in HC-H-lipo was increased compared with that in HPF solution. In contrast, in the reaction with peroxynitrite, HC-H-lipo was inhibited. It was confirmed that HC-H-lipo that reacted specifically with hydroxyl radicals was able to distinguishably detect hydroxyl radicals. It was regarded to be useful as an examination kit. Tissue disorder induced by sodium valproate (SV) was one of the prepared murine disease models. The reactivity ratio of HC-H-lipo with serum to that of HPF solution was markedly different between the normal group (30%) and SV group (70%). In conclusion, HC-H-lipo cannot only simply and directly detect ROS but can also selectively detect ROS type. This nanocarrier is expected to be used as a novel diagnosis method. 相似文献
132.
Asakawa T Hiza A Nakayama M Inai M Oyama D Koide H Shimizu K Wakimoto T Harada N Tsukada H Oku N Kan T 《Chemical communications (Cambridge, England)》2011,47(10):2868-2870
A practical synthesis of nobiletin, a polymethoxylated citrus flavone, was accomplished by utilizing our novel flavone synthesis. Synthetic nobiletin was labelled by selective demethylation and rapid incorporation of (11)C atom. Positron emission tomography images successfully visualized the brain distribution, which may provide therapeutic benefits in the treatment of Alzheimer's disease. 相似文献
133.
An addition of rare earth metals with trivalent cation radii of 1.05-1.15 ? to Fe/BEA zeolites improves hydrothermal stability for selective catalytic reduction of NO by NH(3). 相似文献
134.
Yoshida A Hirooka Y Sugata Y Nitta M Manabe T Ido S Murakami K Saha RK Suzuki T Ohshima M Yoshida A Itoh K Shimizu K Oku N Furuta T Asakawa T Wakimoto T Kan T 《Chemical communications (Cambridge, England)》2011,47(6):1794-1796
A concise synthesis of APDOEGCg (3) was accomplished. Due to the reactivity of its amine group, the compound could be easily converted to the fluorescein probe 21 and immunogen probe 22 efficiently. We then demonstrated the usefulness of the probes for imaging studies and the generation of antibodies. 相似文献
135.
Daisuke Nagai Tsutomu Imazeki Hisatoyo Morinaga Hiroyuki Oku Ken‐Ichi Kasuya 《Journal of polymer science. Part A, Polymer chemistry》2010,48(4):845-851
The three‐component polyaddition of diamines, carbon disulfide (CS2), and diacrylates in water was successfully achieved without the use of a surfactant or catalyst. Appropriate reaction conditions (i.e., reaction temperature, reaction time, and CS2 feed) enabled the polyaddition of 1,3‐di‐4‐piperidylpropane ( 1a ), CS2, and 1,6‐hexanediol diacrylate ( 2a ) to afford the corresponding poly(dithiourethane‐amine) containing 83% of dithiourethane units in 84% yield. Polyaddition of other monomers also proceeded under the optimum conditions to afford various poly(dithiourethane‐amine)s. Unsuccessful results for polyaddition in organic solvents such as toluene, tetrahydrofuran, and N,N‐dimethylformamide revealed that the polyaddition is accelerated in water. The obtained poly(dithiourethane‐amine)s adsorbed Au (III) efficiently under acidic conditions, due to the strong interaction of the thiocarbonyl sulfur in the dithiourethane unit with Au (III). The poly(dithiourethane‐amine)s also showed selective adsorption for Au (III) from a mixture of metal ions [Au (III), Fe (III), Mn (II), and Zn (II)], which indicates their potential utilization for the collection of gold. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 845–851, 2010 相似文献
136.
Tokuzo Konishi Toshio Tsubata Masaoki Oku Yanko M Todorov Masaki Yoshio 《Analytical sciences》2005,21(7):861-864
High-resolution the Mn Kalpha1 X-ray fluorescence spectra (HRXRF) were measured for a variety of manganese compounds, the oxidation number (valence) of which was from II to VII. Plots of the valence against the full width at half maximum (FWHM) and the chemical shift of the Kalpha1 X-ray fluorescence spectra give a curve and a liniar relation, respectively. The coefficient of correlation (R2) for the latter plot was 0.989 between valency II and VII. More excellent linearlity from III to IV was obtained with R2 = 0.995, which enabled us to determine the oxidation number of manganese atom in a nickel ion doped spinel structure, LiMn2O4 (LiNixMn(2-x)O4, with 0.2 < x < 0.42). From the valence of manganese ion obtained from HRXRF, the oxidation number of nickel ion is concluded to be divalent. 相似文献
137.
Naruhiro Koi Takeo Oku Kat suaki Suganuma 《Physica E: Low-dimensional Systems and Nanostructures》2005,29(3-4):541
Possibility of hydrogen gas storage in boron nitride (BN) clusters was investigated by molecular orbital calculations. Chemisorption calculation was carried out for B24N24 with changing endohedral elements in BN cluster to compare the bonding energy at nitrogen and boron, which showed that Li is a suitable element for hydrogenation to B24N24. 相似文献
138.
Masaoki Oku Toetsu ShishidoHideyuki Matsuta Kazuaki Wagatsuma 《Journal of Electron Spectroscopy and Related Phenomena》2006
The background corrected valence band XPS spectra and the electronic structures of FeAl, FeSi, CoAl and CoSi were studied. Clean surfaces of the polycrystalline samples were obtained by in situ fracturing of the samples in an XPS spectrometer. The energy loss parts of the Fe 2p, Co 2p and valence band spectra were removed by the deconvolution method using Al 2s or Si 2s spectra as response functions. CoAl exhibited a satellite peak in the Co 2p region, but the other compounds had no clear satellite peaks in the Co 2p and Fe 2p regions. The experimentally background corrected valence band spectra were compared with the calculated spectra using the first-principle band calculation. There were large discrepancies between the spectra above the binding energy of 5 eV. These indicated that the experimental spectra could not be explained by the electronic structures of the ground states alone. 相似文献
139.
Allergy-preventive flavonoids from Xanthorrhoea hastilis 总被引:1,自引:0,他引:1
Allergy-preventive activity was demonstrated for an extract of resins from Xanthorrhoea hastilis R. BR. in a search for allergy-preventive substances from natural sources. By bioassay-directed fractionation of this plant extract, a new flavanone, 3',5'-dihydroxy-7,4'-dimethoxyflavanone (1), and two new chalcones, 3,5,2'-trihydroxy-4,4'-dimethoxychalcone (2) and 5,2'-dihydroxy-3,4,4'-trimethoxychalcone (3), were isolated together with five known compounds, 5'-hydroxy-7,3',4'-trimethoxyflavanone (4), 3'-hydroxy-7,4'-dimethoxyflavanone (5), liquiritigenin 7-methyl ether (6), 4,2'-dihydroxy-4'-methoxychalcone (7) and sakuranetin (8). The structures of 1, 2 and 3 were elucidated by spectroscopic methods. All of these compounds showed allergy-preventive effects. 相似文献
140.
Structural revision of glabramycin B, which is an antibacterial 10-membered lactone isolated from a fermentation broth of Neosartorya glabra, was achieved by enantioselective synthesis of our proposed structure. The correct structure of glabramycin B was presumed on comparison with related compounds, and synthesis of it was succeeded via dianion alkylation, Shiina's lactonization and Stille cross-coupling. By this synthesis, we were able to correct the reported structural misassignment, and to confirm the relative configuration of glabramycin B to be 10S*,11S*,15R*,20S*. 相似文献