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71.
Yoshinori Kamiya Takuji Hirose Keishin Mizoguchi Yasutoshi Naito 《Journal of Polymer Science.Polymer Physics》1986,24(7):1525-1539
A gravimetric method for determining precisely the solubility of gases in polymers at high pressure is described. The solubilities of N2 and CO2 in low-density polyethylene (LDPE); CO2 in polycarbonate (PC); and N2, CH4, C2H6, and CO2 in polysulfone (PSUL) have been measured as a function of pressure up to 50 atm. Most of the measured sorption isotherms agreed closely with published data, but reproducible and time-dependent hysteresis in the sorption of CO2, C2H6, and CH4 in glassy polymers, PC, and PSUL, was observed in this study for the first time. Like the well known conditioning effect of high-pressure CO2 on the sorption capacity of glassy polymers, these hysteresis phenomena are believed to be due to the plasticizing effect of sorbed gases. On the basis of the current data, the dual-mode sorption model including the plasticization by sorbed gas is discussed and a primitive equation for the concentration of sorbed gases in a quasiequilibrium state of sorption or desorption is proposed. 相似文献
72.
The surface of a TiO2 film electrode, about 1 μm thick, prepared by the sol-gel method, was modified by being additionally coated with about 0.1 μm thick TiO2---SiO2, TiO2---ZrO2 or TiO2---Al2O3 films. The effect of the additional coating on the photoelectrochemical properties of a TiO2 film electrode was investigated in detail. On addition of the second additive to TiO2, the flat band potential was shifted toward negative potential for SiO2 and positive potential for ZrO2 and Al2O3, which is attributed to the change in the point of zero zeta potential (pzzp), not in the electron affinity (EA). However, enhancement in photocurrent was not observed for all the cases. 相似文献
73.
Bioactive polymers were sought in marine arthropoda and a novel cytolytic factor was found in a hermit crab, Clibanarius longitarsus. The partially purified factor showed activity in fractions corresponding to a molecular weight of about 10 kilodaltons on a Sephadex G-75 column. This cytolytic factor was halfmaximally active for tumor cells at 0.13-0.66 micrograms/ml and for normal cells at 1.9-82 micrograms/ml. Tumor lysis by the factor was time dependent and was complete within 12 h. This bioactive polymer was labile on heating, at low and high pH. 相似文献
74.
Hiroharu Yui Daisuke Sawada Shoko Kamiya Tsuguo Sawada Toshimi Shimizu 《Analytical sciences》2004,20(11):1549-1552
We utilized oil/water interfaces as a new field to produce lipid nanotubes (LNTs), which are formed by the self-assembly of lipid molecules, and possess hollow nanometer-wide cylindrical structures. Compared to the self-assembling field in bulk water, oil/water interfaces produced shorter lipids nanotubes less than 10 microm long more efficiently. In addition, we found that the oil/water interface accumulates lipid nanotubes spontaneously. This methodology is favorable to fabricate LNTs as new nano-fluidic devices, or sensors that require accumulation and alignment in two dimensions. 相似文献
75.
Jørgensen's inequality gives a necessary condition for a nonelementary two generator group of isometries of hyperbolic space to be discrete. We give analogues of Jørgensen's inequality for nonelementary groups of isometries of complex hyperbolic 2-space generated by two elements, one of which is either loxodromic or boundary elliptic. These results give an improvement over earlier results of Basmajian and Miner. 相似文献
76.
A Reversible Fluorescent Probe for Real‐Time Live‐Cell Imaging and Quantification of Endogenous Hydropolysulfides 下载免费PDF全文
Dr. Keitaro Umezawa Dr. Mako Kamiya Prof. Dr. Yasuteru Urano 《Angewandte Chemie (International ed. in English)》2018,57(30):9346-9350
The chemical biology of reactive sulfur species, including hydropolysulfides, has been a subject undergoing intense study in recent years, but further understanding of their “intact” function in living cells has been limited owing to a lack of appropriate analytical tools. In order to overcome this limitation, we developed a new type of fluorescent probe that reversibly and selectively reacts to hydropolysulfides. The probe enables live‐cell visualization and quantification of endogenous hydropolysulfides without interference from intrinsic thiol species such as glutathione. Additionally, real‐time reversible monitoring of oxidative‐stress‐induced fluctuation of intrinsic hydropolysulfides has been achieved with a temporal resolution on the order of seconds, a result which has not yet been realized using conventional methods. These results reveal the probe's versatility as a new fluorescence imaging tool to understand the function of intracellular hydropolysulfides. 相似文献
77.
Shindou Takuya Katayama Shingo Yamada Noriko Kamiya Kanichi 《Journal of Sol-Gel Science and Technology》2003,27(1):15-21
Polydimethylsiloxane (PDMS)-based inorganic/organic hybrids films were prepared on polyimide sheets by the sol-gel method using silanol-terminated PDMS and titanium tetraisopropoxide as starting materials. The effect of heat-treatment temperature on the surface property of the hybrid films was examined in terms of contact angle of water and Tapping-Mode Atomic Force Microscopy (AFM). AFM phase images showed the presence of domains, 200–500 nm in size, on the surface of these films after heat-treatment below 300°C. These regions were more hydrophilic than the rest of the area. The domains disappeared at 300°C and the surface became homogeneous surface of the peak to valley value, about 10 nm. It is also uniformly hydrophobic and a maximum contact angle (about 115°C) was obtained. 相似文献
78.
The mechanism of the accumulation of basic drugs was investigated by isolated rat lung perfusion. Treatment with various metabolic inhibitors or non-basic drugs did not affect the accumulation of a basic drug in the lung, but a second basic drug inhibited the accumulation of the first basic drug depending on its lipid solubility. The basic drug already accumulated was rapidly displaced by the second drug except for poorly lipid-soluble basic drugs and non-basic drugs. The ability of a second basic drug to displace the first basic drug was well correlated with its ability to inhibit accumulation. From the Scatchard plot, at least two independent sets of binding sites for basic drugs were found to be present in the isolated perfused lung. The maximum binding capacity for each basic drug was similar in both sites. These results indicate that specific common binding sites for basic drugs, which do not contribute to the active transport system, exist in the lung tissues and the affinity to the sites depends on the lipid solubility of the basic drugs. 相似文献
79.
Kamiya S Shirahase H Yoshimi A Nakamura S Kanda M Matsui H Kasai M Takahashi K Kurahashi K 《Chemical & pharmaceutical bulletin》2000,48(6):817-827
We synthesized a series of indoline derivatives with an amide or urea moiety and examined their inhibitory effects on acyl-CoA:cholesterol acyltransferase (ACAT) activity, lipid-peroxidation and serum cholesterol levels in experimental animals. Among the derivatives synthesized, a series of N-(1-alkyl-4,6-dimethylindolin-7-yl)-2,2-dimethylpropanamides++ + potently inhibited rabbit intestinal ACAT activity and lipid-peroxidation of rat brain homogenate. The effect on ACAT activity was related to the length of the alkyl chain at the 1-position of indoline. N-(4,6-Dimethyl-1-octylindolindolin-7-yl)-2,2-dimethylpropanami de hydrochloride (55) showed inhibitory effects on intestinal and hepatic ACAT activity slightly weaker than those of YM-750, and an inhibitory effect on low density lipoprotein (LDL)-peroxidation similar to that of probucol. Compound 55 also reduced serum cholesterol at 10 mg/kg/d in hyperlipidemic rats and 20 mg/kg/d in normolipidemic hamsters. The plasma concentration of 55 reached 716 ng/ml in dogs (10 mg/kg, p.o.), which is an effective concentration against hepatic ACAT activity and LDL-peroxidation. In conclusion, compound 55 is a novel bioavailable ACAT inhibitor with anti-peroxidative activity and is thus a promising anti-atherosclerotic and anti-hyperlipidemic drug. Indoline proved to be a useful pharmacophore for molecular design of new anti-peroxidative drugs. 相似文献
80.
Yuichi Kamiya 《Reaction Kinetics and Catalysis Letters》2005,84(2):271-278
Summary 1% of Fe-doped and undoped vanadyl pyrophosphate catalysts were prepared via dihydrate method. The catalysts have been characterised by XRD, ICP, BET and SEM. The undoped catalyst was found to be more active and selective (77.6% selectivity at about 60 % conversion at 703 K). 相似文献