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51.
Purification and characterization of a protease from Pseudomonas aeruginosa grown in cutting oil 总被引:2,自引:0,他引:2
The Pseudomonas aeruginosa san-ai strain was isolated from water-soluble cutting oil used for cooling and lubrication during industrial metal-working processes. This strain, which is grown in a high alkaline (pH 10) mixture of surfactants and mineral oil, produces an extracellular proteolytic enzyme. We have purified and characterized this 18 kDa protease. The P. aeruginosa san-ai protease functions optimally at pH 9.0 and 60 degrees C. Additionally, it is a Zn-containing metalloenzyme, and its monomeric structure contains at least one disulfide bond. Because the enzyme is stable in the presence of organic solvents, it is suitable for peptide synthesis. Furthermore, the P. aeruginosa san-ai protease could be used in an intelligent drug delivery system (DDS) designed for applications in the metal industry for prevention of putrefaction of cutting oil. 相似文献
52.
Atomic force microscopy (AFM) can dynamically detect the adhesion or affinity force between a sample surface and a cantilever. This feature is useful as a detection method using aptamers--single-strand DNA that recognizes its target with very high affinity. The present study proposes a novel DNA aptamer-based sensing system using AFM. In this study, thrombin was chosen as the target molecule, and a DNA aptamer-based AFM sensing system based on competition was developed. The affinity force between the gold chip and the cantilever decreased as the concentration of thrombin increased. Moreover, a low detection limit of 0.2 nM was achieved. Therefore, the AFM sensing system used would be appropriate for the measurement of various chemical compounds. 相似文献
53.
Akihiko Ito Dongyun Guo Rong Tu Takashi Goto 《Journal of the European Ceramic Society》2012,32(10):2459-2467
Barium dititanate (BaTi2O5) thick films were prepared on a Pt-coated Si substrate by laser chemical vapor deposition, and ac electric responses of (0 2 0)-oriented BaTi2O5 films were investigated using several equivalent electric circuit models. BaTi2O5 films in a single phase were obtained at a Ti/Ba molar ratio (mTi/Ba) of 1.72–1.74 and deposition temperature (Tdep) of 908–1065 K as well as mTi/Ba = 1.95 and Tdep = 914–953 K. (0 2 0)-oriented BaTi2O5 films were obtained at mTi/Ba = 1.72–1.74 and Tdep = 989–1051 K. BaTi2O5 films had columnar grains, and the deposition rate reached 93 μm h?1. The maximum relative permittivity of the (0 2 0)-oriented BaTi2O5 film prepared at Tdep = 989 K was 653 at 759 K. The model of an equivalent circuit involving a parallel combination of a resistor, a capacitor, and a constant phase element well fitted the frequency dependence of the interrelated ac electrical responses of the impedance, electric modulus, and admittance of (0 2 0)-oriented BaTi2O5 films. 相似文献
54.
Transparent lutetium aluminum garnet (Lu3Al5O12, LuAG) was fabricated by reactive spark plasma sintering. The effect of sintering temperature on the crystal phase, microstructure, transparency and mechanical properties of LuAG bodies was investigated. Fully dense and single-phase LuAG bodies were obtained at sintering temperatures 1573–1923 K. The average grain size increased from 0.18 to 0.52 μm with increasing sintering temperature from 1573 to 1773 K, and grain growth became significant at 1823 K. Transmittance showed a maximum value of 77.8% at 2000 nm at a sintering temperature of 1773 K after annealing at 1423 K in air for 43.2 ks. The Vickers hardness increased from 14.2 to 17.2 GPa with decreasing grain size from 7.45 to 0.23 μm. 相似文献
55.
Tetsuro Hori Naoki Fukuoka Tetsuya Masuda Yasuo Miyake Hiroyuki Yoshida Akihiko Fujii Yo Shimizu Masanori Ozaki 《Solar Energy Materials & Solar Cells》2011,95(11):3087-3092
Bulk heterojunction solar cells utilizing soluble phthalocyanine derivative, 1,4,8,11,15,18,22,25-octahexylphthalocyanine (C6PcH2) have been investigated. The active layer was fabricated by spin-coating the mixed solution of C6PcH2 and 1-(3-methoxy-carbonyl)-propyl-1-1-phenyl-(6,6)C61 (PCBM). The photovoltaic properties of the solar cell with bulk heterojunction of C6PcH2 and PCBM demonstrated the strong dependence of active layer thickness, and the optimized active layer thickness was clarified to be 120 nm. By inserting MoO3 hole transport buffer layer between the positive electrode and active layer, the FF and energy conversion efficiency were improved to be 0.50 and 3.2%, respectively. The tandem organic thin-film solar cell has also been studied by utilizing active layer materials of C6PcH2 and poly(3-hexylthiophene) and the interlayer of LiF/Al/MoO3 structure, and a high Voc of 1.27 V has been achieved. 相似文献
56.
Akihiko Ito Yu You Hirokazu Katsui Takashi Goto 《Journal of the European Ceramic Society》2013,33(13-14):2655-2661
Ba β-alumina films were prepared by laser chemical vapor deposition. Mostly single-phase Ba β-alumina films were obtained at 1125–1200 K and for an Al/Ba molar ratio of 12.4–16.6. BaAl2O4 and α-Al2O3 were codeposited with Ba β-alumina under Ba- and Al-rich conditions, respectively. The Ba β-alumina films consisted of hexagonal grains, and the (1 1 0)-oriented Ba β-alumina films had a fin-like columnar structure. The highest deposition rate reached 120 μm h?1 at around 1200 K. A thin layer of Ba-rich superstructure was formed on the surface of the (1 1 0)-oriented columnar grains. 相似文献
57.
Yasuhisa Ishikawa Akihiko Iwai Susumu Nishiwaki Tadashi Koshizuka Tsuneharu Teranishi Kyouichi Uehara 《Electrical Engineering in Japan》2004,146(2):20-26
Investigations were conducted on the VFT (Very Fast Transient) surges that propagate into a 500‐kV transformer. The disconnector restriking surge and ground fault surged were discussed. It was regarded that a large part of the surge voltage was applied just at the entrance of the transformer winding for the VFT surges. Thus, an equivalent circuit that models the windings was used for the analysis. The overvoltages that appear between the first winding sections at the entrance of the transformer were computed. The following was established. (1) The overvoltage between the first winding sections becomes greater when the magnitude of the voltage change at the transformer terminal is larger. The overvoltage between the first winding sections is not affected by the magnitude of the transformer terminal voltage. (2) For the disconnectors that are not connected directly to the transformer, the voltage change at the transformer terminal is not so large. (3) In the case of a ground fault at the GIS near the transformer, the voltage change at the transformer terminal is the same as that for a disconnector directly connected to the transformer. (4) In actual GIS, the disconnector that is connected directly to the transformer is not usually used. In this situation, the overvoltages that threaten the transformer insulation will not be generated by the restriking of the disconnectors. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 146(2): 20–26, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10225 相似文献
58.
Masahiro Fujimoto Mamoru Ishida Akihiko Fujii Yoshimine Sakamoto Norifumi Fujita Seiji Shinkai Masanori Ozaki 《Synthetic Metals》2009,159(9-10):871-874
The molecular alignment of polydiacetylene (PDA) derivatives and their optical and electrical properties of thin films based on PDA derivatives have been studied. The PDA derivatives were aligned depending on the direction of applied shear stress in the film. From measurements of the polarized absorption and current–voltage characteristics, the optical and electrical anisotropies have been observed, that was discussed by taking the PDA main chain alignment into consideration. 相似文献
59.
Phosphonium salts with different alkyl chains as substituents were incorporated covalently on the surfaces of cellulose filters with silane coupling agents containing phosphonium ions, and their surface antibacterial activities against Staphylococcus aureus and Escherichia coli were explored by the viable cell-counting method in sterile distilled water. The filters incorporating phosphonium biocides showed higher antibacterial activity, and its activity strongly depended on the structure of substituents. The surface-treated filters may be used to sterilize air and water, including microorganisms. © 1994 John Wiley & Sons, Inc. 相似文献
60.
Yasutaka Nagai Takashi Yamamoto Tsunehiro Tanaka Satohiro Yoshida Takamasa Nonaka Tokuhiko Okamoto Akihiko Suda Masahiro Sugiura 《Catalysis Today》2002,74(3-4):225-234
Three types of CeO2–ZrO2 (Ce:Zr=1:1 molar ratio) compounds with different oxygen storage/release capacities (OSCs) were characterized by means of the Ce K-edge and Zr K-edge X-ray absorption fine structure (XAFS). In order to investigate the relationship between the OSC and local structure, the quantitative EXAFS curve-fitting analysis was applied. By enhancing the homogeneity of the Ce and Zr atoms in the CeO2–ZrO2 solid solution, the OSC performance increased. Especially, the atomically homogeneous Ce0.5Zr0.5O2 solid solution exhibited the highest OSC among these CeO2–ZrO2 samples. Additionally, the local oxygen environment around Ce and Zr was remarkably modified by enhancing the homogeneity of the CeO2–ZrO2 solid solution. It was postulated that the enhancement of the homogeneity of the CeO2–ZrO2 solid solution and the modification of the oxygen environment would be the source for the OSC improvement. 相似文献