直鎖型ポリユビキチン化の構造基盤

京都大学0048新制・課程博士博士(工学)甲第21791号工博第4608号新制||工||1718(附属図書館)京都大学大学院工学研究科分子工学専攻(主査)教授 白川 昌宏, 教授 佐藤 啓文, 教授 跡見 晴幸学位規則第4条第1項該当Doctor of Philosophy (Engineering)Kyoto UniversityDGA

Possible Excitonic Phase of Graphite in the Quantum Limit State

The in-plane resistivity, Hall resistivity and magnetization of graphite were investigated in pulsed magnetic fields applied along the \textit{c}-axis. The Hall resistivity approaches zero at around 53 T where the in-plane and out-of-plane resistivities steeply decrease. The differential magnetization also shows an anomaly at around this field with a similar amplitude compared to that of de Haas-van Alphen oscillations at lower fields. This transition field appears insensitive to disorder, but reduces with doping holes. These results suggest the realization of the quantum limit states above 53 T. As a plausible explanation for the observed gapped out-of-plane conduction above 53 T, the emergence of the excitonic BCS-like state in graphite is proposed.Comment: 15 pages, 6 figures, to be published in J. Phys. Soc. Jp

Magnetization Plateaus in the Spin-1/2 Kagome Antiferromagnets: Volborthite and Vesignieite

The magnetization of two spin-1/2 kagome antiferromagnets, volborthite and vesignieite, has been measured in pulsed magnetic fields up to 68 T. A magnetization plateau is observed for each compound near the highest magnetic field. Magnetizations at saturation are approximately equal to 0.40Ms for both compounds, where Ms is the fully saturated magnetization, irrespective of a difference in the distortion of the kagome lattice between the two compounds. It should be noted that these values of magnetizations are significantly larger than Ms/3 predicted theoretically for the one-third magnetization plateau in the spin-1/2 kagome antiferromagnet. The excess magnetization over Ms/3 is nearly equal to the sum of the magnetizations gained at the second and third magnetization steps in volborthite, suggesting that there is a common origin for the excess magnetization and the magnetization steps.Comment: 4 pages, 4 figures. Phys. Rev. B, accepte

High-spectral resolution observations of the 3.29 micron emission feature: Comparison to QCC and PAHs

Two of the most promising explanations for the origin of the interstellar emission features observed at 3.29, 3.4, 6.2, 7.7, 8.6, and 11.3 microns are: quenched carbonaceous composite (QCC) and polycyclic aromatic hydrocarbons (PAHs). High resolution spectra are given of the 3.29 micron emission feature which were taken with the Cooled Grating Array Spectrometer at the NASA Infrared Telescope Facility and previously published. These spectra show that the peak wavelength of the 3.29 micron feature is located at 3.295 + or - 0.005 micron and that it is coincident with the peak absorbance of QCC. The peak wavelength of the 3.29 micron feature appears to be the same in all of the sources observed thus far. However, the width of the feature in HD 44179 and Elias 1 is only 0.023 micron, which is smaller than the 0.043 micron width in NGC 7027, IRAS 21282+5050, the Orion nebula, and BD+30 deg 3639. Spectra of NGC 7027, QCC, and PAHs is shown. QCC matches the 3.29 micron interstellar emission feature very closely in the wavelength of the peak, and it produces a single feature. On the other hand, PAHs rarely match the peak of the interstellar emission feature, and characteristically produce multiple features

Octacosanol Attenuates Disrupted Hepatic Reactive Oxygen Species Metabolism Associated with Acute Liver Injury Progression in Rats Intoxicated with Carbon Tetrachloride

We examined whether octacosanol, the main component of policosanol, attenuates disrupted hepatic reactive oxygen species metabolism associated with acute liver injury progression in rats intoxicated with carbon tetrachloride (CCl4). In rats intoxicated with CCl4 (1 ml/kg, i.p.), the activities of serum transaminases increased 6 h after intoxication and further increased at 24 h. In the liver of CCl4-intoxicated rats, increases in lipid peroxide (LPO) concentration and myeloperoxidase activity and decreases in superoxixde dismutase activity and reduced glutathione (GSH) concentration occurred 6 h after intoxication and these changes were enhanced with an increase in xanthine oxidase activity and a decrease in catalase activity at 24 h. Octacosanol (10, 50 or 100 mg/kg) administered orally to CCl4-intoxicated rats at 6 h after intoxication attenuated the increased activities of serum transaminases and the increased hepatic myeloperoxidase and xanthine oxidase activities and LPO concentration and the decreased hepatic superoxide dismutase and catalase activities and GSH concentration found at 24 h after intoxication dose-dependently. Octacosanol (50 or 100 mg/kg) administered to untreated rats decreased the hepatic LPO concentration and increased the hepatic GSH concentration. These results indicate that octacosanol attenuates disrupted hepatic reactive oxygen species metabolism associated with acute liver injury progression in CCl4-intoxicated rats

Elimination of metal interference in the determination of fluoride ion by non-suppressor type ion chromatography

A simple method has been developed to eliminate metal interferences in the ion-chromatographic determination of fluoride ion in aqueous solutions. Negative interferences become appreciable on 0.2-mM F at 0.01 to 0.02 mM of Al(III), Ce(IV), La(III), Y(III), Ce(III) and Pb(II); and at 0.25 mM of Ca(II). The interference from Cd(II), Co(II), Fe(II) and Ni(II) is insignificant at ≤ 5.0-mM metal for 5.0-mM F-. By alkalifying F- solutions at pH 12.3, the metal interference can be eliminated up to the concentrations of 0.25-mM Al(III), La(III) and Y(III); 1.0-mM Ce(IV); 2.5-mM Ce(III); and 5.0-mM Pb(II), Cd(II), Co(II), Fe(II) and Ni(II). The Ca(II) interference cannot be eliminated. The pretreatment enables determination of 0.2- to 5.0-mM F- in presence of 0.25-mM Al(III) or La(III) with coefficient-of-variations of 1.99 to 6.20%