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531.
Miyake T Tanii T Sonobe H Akahori R Shimamoto N Ueno T Funatsu T Ohdomari I 《Analytical chemistry》2008,80(15):6018-6022
Real-time imaging of single-molecule fluorescence with a zero-mode waveguide (ZMW) was achieved. With modification of the ZMW geometry, the signal-to-background ratio is twice that obtainable with a conventional ZMW. The improved signal-to-background ratio makes it possible to visualize individual binding-release events between chaperonin GroEL and cochaperonin GroES at a concentration of 5 microM. Two rate constants representing two-timer kinetics in the release of GroES from GroEL were measured with the ZMW, and the measurements agreed well with those made with a total internal reflection fluorescence microscopy. These results indicate that the novel ZMW makes feasible the direct observation of protein-protein interaction at an intracellular concentration in real time. 相似文献
532.
Dr. Takahiro Ugai Dr. Atsushi Minami Shizuya Tanaka Dr. Taro Ozaki Dr. Chengwei Liu Prof. Dr. Hideyuki Shigemori Prof. Dr. Masaru Hashimoto Prof. Dr. Hideaki Oikawa 《Chembiochem : a European journal of chemical biology》2020,21(3):360-367
Oxygenated cyclopentene systems are unique structural motifs found in fungal polyketides such as terrein, cyclohelminthols, and palmaenones. Here we report the identification of the biosynthetic gene clusters for cyclohelminthols and palmaenones and the functional characterization of the polyketide synthases and halogenases involved in the construction of 6-hydroxymellein derivatives. Heterologous expression in Aspergillus oryzae demonstrated that 6-hydroxymellein is a common biosynthetic intermediate and that chlorination occurs in the early stages of its products’ biosynthesis. This was further confirmed by in vitro enzymatic reactions conducted in the presence of recombinant proteins. Plausible means of biogenesis of fungal polyketides from 6-hydroxymellein derivatives, additionally supported by the reported labeling patterns of terrein and structurally related fungal polyketides, are also discussed. This study sets the stage for elucidation of the biosynthetic machinery of fungal polyketides of this type. 相似文献
533.
Lithium ions were extracted from aqueous solutions into cyclohexane containing di-(2-ethylhexyl)phosphoric acid (D2EHPA) through slug flow in millimeter-diameter glass and polytetrafluoroethylene (PTFE) tubes. The PTFE tube produced a higher initial mass transfer coefficient than the glass tube by increasing internal circulation in the organic phase, and maintained its specific surface area. Slug flow occurred in the PTFE tube when the interfacial tension between the aqueous and organic phases exceeded 50–55 mN/m, which increased the rate of extraction owing to increased circulation in both phases. The addition of tributyl phosphate (TBP) enhanced the extraction efficiency, but did not affect the extraction rate. 相似文献
534.
Kohei Miyazaki Masafumi Nose Taro Kinumoto Takeshi Abe Tomokazu Fukutsuka Zempachi Ogumi 《Carbon》2012,50(4):1644-1649
Graphite electrodes, whose surface is partially covered with metal oxides, are prepared by the electrochemical deposition of MoOx, WOx, and SnO2 particles, and their corrosion behaviors under the imposed electrochemical potential conditions are investigated. Scanning electron microscopy observation shows that highly oriented pyrolytic graphites (HOPGs) modified with MoOx and WOx particles (MoOx|HOPG and WOx|HOPG) suffer from carbon corrosion and show pits formation on the surface of HOPG after an electrochemical potential cycling in a range of 0.8–1.0 V. In contrast, SnO2-modified HOPG (SnO2|HOPG) exhibits superior tolerance to electrochemical oxidation. Cyclic voltammograms show that the SnO2 modification prevents an increase in the redox currents for quinone/hydroquinone reactions and the electrochemical double layer capacitances on the HOPG electrode. These results indicate that the influence of metal oxides on carbon corrosion varies depending on the kind of metal oxides, and that SnO2 is a proper choice to protect the surface of HOPG from carbon corrosion, under electrochemical potentials. 相似文献
535.
Warapong Krengvirat Srimala Sreekantan Ahmad-Fauzi Mohd Noor Charoen Chinwanitcharoen Hiroyuki Muto Atsunori Matsuda 《Ceramics International》2012,38(4):3001-3009
Bismuth titanate (BIT) ceramics were prepared by incorporating low-temperature self-combustion synthesis and pH modification. The pH value of the initial precursor was adjusted to 3, 5 and 7 by the addition of ammonium hydroxide (NH4OH) with different amount. The reaction between ammonium ions (NH4+) and nitrate ions (NO3?) induced the formation of ammonium nitrate (NH4NO3), in turn to favor the combustion by enhancing the decomposition rate. Excessive hydroxyl ions (OH?) at higher pH value dominated the chelating of the metal carboxylate and the metal ions, resulting in a strong hybridization between bismuth (Bi) and oxygen (O), and also the suppression of the independent volatility of Bi and bismuth oxide (Bi2O3). Such conditions contributed to the formation of pure BIT via the low-temperature self-combustion synthesis without the use of an additional fuel agent. A BIT ceramic with high relative density (91.35%) that exhibited a high dielectric constant of ~340 and a low dissipation factor ~0.028 was obtained by the synthesis method at the neutral condition. Furthermore, it offers ability for the use in high temperature applications up to 675 °C. 相似文献
536.
Hiroshi Kanno Atsuhiko Kubo Tetsuya Yoshizumi Taro Mikami Jiro Maegawa 《International journal of molecular sciences》2013,14(5):9604-9617
A specialized population of cells residing in the hair follicle is quiescent but shows pluripotency for differentiating into epithelial-mesenchymal lineage cells. Therefore, such cells are hoped to be useful as implantable donor cells for regenerative therapy. Recently, it was reported that intracellular delivery of TAT-VHL peptide induces neuronal differentiation of skin-derived precursors. In the present study, we successfully isolated multipotent stem cells derived from the epidermis of elderly humans, characterized these cells as being capable of sphere formation and strong expression of nestin, fibronectin, and CD34 but not of keratin 15, and identified the niche of these cells as being the outer root sheath of the hair follicles. In addition, we showed that TAT-VHL peptide induced their neuronal differentiation in vitro, and confirmed by fluorescence immunohistochemistry the neuronal differentiation of such peptide-treated cells implanted into rodent brains. These multipotent nestin-expressing stem cells derived from human epidermis are easily accessible and should be useful as donor cells for neuronal regenerative cell therapy. 相似文献
537.
538.
Matsuoka R Muto A Kimura M Hoshina R Wakamatsu T Masuda Y 《Journal of oleo science》2008,57(5):309-314
Free plant sterols cannot be dissolved in oil or water. Using free plant sterols and egg yolks, we developed a plant sterol-egg yolk lipoprotein complex (PSY) that can be dispersed in water and considered suitable for use in processed foods. The cholesterol-lowering activity of PSY was equal to that of free plant sterols and plant sterol esters. Consumption of a freeze-dried PSY-containing omelet reduced serum and hepatic cholesterol concentrations. The results suggest that PSY has cholesterol-lowering activity equivalent to that of free plant sterols and plant sterol esters. Moreover, the cholesterol-lowering activity of PSY was maintained in processed foods. 相似文献
539.
Makoto Tachibe Ryo Kato Shozo Sugano Taro Kishida Kiyoshi Ebihara 《Journal of food science》2009,74(7):H232-H236
ABSTRACT: The hypoglycemic and antidiabetic effect of hydroxypropyl tapioca starch (HPTS, degree of substitution = 0.180) was investigated in male KKAy mice. Mice were fed a purified high-fat (20%) diet without or with HPTS (5% or 10%) for 33 d. Gelatinized tapioca starch (TS) was used as a reference. Fasting blood glucose concentrations, days 14 and 28, were significantly lower in the 10% HPTS group compared with the reference. In an oral glucose tolerance test (OGTT), day 28, blood glucose concentrations in the 5% HPTS group, at 60, 90, and 120 min, and in the 10% HPTS group, at 30, 60, and 90 min after oral administration of glucose, were significantly lower compared with the reference. The area under the glucose curve (AUC) for glucose in both HPTS groups was significantly lower compared with the reference. Energy intake was significantly lower in the 10% HPTS group compared with the reference. At the end of the experiment, adiponectin concentrations were significantly higher in the 10% HPTS group compared with the reference. A homeostasis model assessment of insulin resistance (HOMA-IR) tended to be lower in the 10% HPTS group compared with the reference, whereas a quantitative insulin sensitivity check index (QUICKI) was significantly higher in both HPTS groups compared with the reference. These results show that HPTS retards the development of insulin resistance in KKAy mice fed a high-fat diet. 相似文献
540.