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111.
112.
Nakata K Sakamoto M Taguchi S Yoshida N Shimazu K 《Journal of colloid and interface science》2005,288(2):634-637
The water-insoluble poly-beta-cyclodextrin (poly-CD)/Nafion composite film was easily prepared by casting a mixed solution of poly-CD and Nafion onto substrate plates. FT-IR measurements showed that the 50/50 wt% poly-CD/Nafion composite film remained stable on the glass and quartz substrates after immersion in water for more than 3 h, while a pure poly-CD film was almost completely dissolved by immersion within 1 h. The film stability was also evaluated from the amount of p-nitrophenol (p-NP) inclusion in the film, which was determined from the decrease in UV-vis absorbance of the p-NP solution into which the film was immersed. The composition dependence of the inclusion amount showed that the film was stable up to 50 wt% CD, but became less stable with further increase in the CD concentration in the film. From the isotherms for the inclusion of p-NP and 1-naphthoate (1-Naph) into the film, the inclusion (stability) constants were determined to be 3.7x10(3) M(-1) and 1.9x10(2) M(-1), respectively. These results show that the selective inclusion of CD is retained after preparation of the composite film. 相似文献
113.
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115.
Shinji Nishitani Nobuyuki Kurata Yoshiteru Sakata Soichi Misumi Masahito Migita Tadashi Okada Noboru Mataga 《Tetrahedron letters》1981,22(22):2099-2102
To clarify the primary process of photosynthesis, a series of model compounds, in which an octaethylporphyrin and a benzoquinone ring are connected with different lengths of a polymethylene chain, were synthesized and their photophysical properties were investigated. 相似文献
116.
The energy transfer process to guest molecule5 m poly(N-vinylcarbJZole) films WJS directly nir.isurcd In (lie film con- taining pciylencihc sandwich excimer site opcralcs as an cncrEy donor, while the evciple't si-itc composed ofthccaiba2olc- dirnettiyl IcrcphtliaJate pair is fornied by trapping tlie migrating monomer fluorescent state. 相似文献
117.
In the radiolysis of water vapor containing small concentrations of cyclohexane, the principal products which account for about 98% of all end products are found to be hydrogen, cyclohexene, and bicyclohexyl. Cyclohexene and bicyclohexyl yields were determined over a range of temperatures (70–200°C), total pressures (50–2400 torr), and total doses (0.15–2.0 Mrad). The disproportionation–combination ratio k/k for c-C6H11 radicals could be determined as 0.56 ± 0.01 from the ratio of cyclohexene to bicyclohexyl yield. By using c-C6D12, the ratio k/k for c-C6D11 radicals is found to be 0.38 ± 0.01. Comparison of the reactivity pattern of C6H11 and C6D11 radicals leads to (k)/(k)/(k/k) = 1.47 ± 0.02. The corresponding values for the reactions of c-C6H11 with c-C6D11 were also determined. 相似文献
118.
119.
Hamasaki T Kashiwagi T Imada T Nakamichi N Aramaki S Toh K Morisawa S Shimakoshi H Hisaeda Y Shirahata S 《Langmuir : the ACS journal of surfaces and colloids》2008,24(14):7354-7364
There are few reports on the physiological effects of metal nanoparticles (nps), especially with respect to their functions as scavengers for superoxide anion radical (O2(.-)) and hydroxyl radical (.OH). We tried to detect the scavenging activity of Pt nps using a hypoxanthine-xanthine oxidase system for O2(.-) and using a Fenton and a UV/H2O2 system for .OH. Electron spin resonance analysis revealed that 2 nm particle size Pt nps have the ability to scavenge O2(.-) and .OH. The calculated rate constant for the O2(.-)-scavenging reaction was 5.03 +/- 0.03 x 10(7) M (-1) s (-1). However, the analysis of the Fenton and UV/H 2O 2 system in the presence of Pt nps suggested that the .OH-scavenging reaction cannot be determined in both systems. Among particle sizes tested from 1 to 5 nm, 1 nm Pt nps showed the highest O2(.-)-scavenging ability. Almost no cytotoxicity was observed even after adherent cells (TIG-1, HeLa, HepG2, WI-38, and MRC-5) were exposed to Pt nps at concentrations as high as 50 mg/L. Pt nps scavenged intrinsically generated reactive oxygen species (ROS) in HeLa cells. Additionally, Pt nps significantly reduced the levels of intracellular O2(.-) generated by UVA irradiation and subsequently protected HeLa cells from ROS damage-induced cell death. These findings suggest that Pt nps may be a new type of antioxidant capable of circumventing the paradoxical effects of conventional antioxidants. 相似文献
120.
Ito H Saito T Oshima N Kitamura N Ishizaka S Hinatsu Y Wakeshima M Kato M Tsuge K Sawamura M 《Journal of the American Chemical Society》2008,130(31):10044-10045
Reversible mechanochromic luminescence of [(C6F5Au)2(mu-1,4-diisocyanobenzene)] is reported. Grinding of the complex induced a photoluminescent color change, which was restored by exposure to a solvent. This cycle was repeated 20 times with no color degradation in the emissions. Their optical properties, X-ray crystallographic analysis, IR, and XRD measurements strongly suggested that the change in the molecular arrangement is responsible for this mechanochromic property. Intermolecular aurophilic bondings presumably play a key role in the altered emission. 相似文献