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排序方式: 共有902条查询结果,搜索用时 62 毫秒
61.
Kim J Yamasaki R Park J Jung H Lee H Kawai T 《Journal of Bioscience and Bioengineering》2004,97(2):138-140
Protein adsorption on a gold surface is investigated by comparing the results of quartz crystal microbalance method and atomic force microscopy. The adsorption of streptavidin on functional gold surfaces is directly monitored by a quartz crystal microbalance, and confirmed by atomic force microscopy. For this investigation, a modified gold substrate is fabricated to obtain a topographic image of streptavidin molecules. Both methods show a correlation in terms of the highly dense protein single-layer formation, and the modified gold electrode shows a slightly denser protein layer formation because of the difference in substrate geometry as compared with that of a mica surface. 相似文献
62.
Kawai E Akatsuka H Sakurai N Idei A Matsumae H Shibatani T Komatsubara S Omori K 《Journal of Bioscience and Bioengineering》2001,91(4):409-415
We have isolated a lipase-overproducing mutant, GE14, from Serratia marcescens 8000 after three rounds of N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis. The mutant GE14 produced 95 kU/ml of extracellular lipase in the lipase medium, which was about threefold higher than that of produced by the original strain 8000. Enzymatic characteristics including specific activity of purified lipases from culture supernatants of GE14 and 8000 were almost same. The lipase gene (lipA) of GE14 contained two base substitutions; one in the promoter region and another in the N-terminal region of the lipA gene without an amino acid substitution. Promoter analysis using lipA-lacZ fusion plasmids revealed that these substitutions were responsible for the increase in the lipA expression level, independently. In contrast, no base substitution was found in the genes encoding the lipase secretion device, the Lip system. In addition, the genes coding for metalloprotease and the cell surface layer protein which are both secreted through the Lip system and associated with extracellular lipase production, also contained no base substitution. The strain GE14 carrying a high-copy-number lipA plasmid produced a larger amount of the extracellular lipase than the recombinant strains of 8000 and other mutants also did, indicating that GE14 was not only a lipase-overproducing strain, but also an advantageous host strain for overproducing the lipase by a recombinant DNA technique. These results suggest that the lipase-overproducing mutant GE14 and its recombinant strains are promising candidates for the industrial production of the S. marcescens lipase. 相似文献
63.
Determination of alkylphenols,bisphenol A,benzophenone and phthalates in containers of baby food,and migration into food simulants 总被引:2,自引:0,他引:2
Ozaki A Yamaguchi Y Okamoto A Kawai N 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2002,43(4):260-266
Infants, whose growth and development are highly dependent upon the endocrine system, are particularly vulnerable to endocrine disruptor exposure. In our study, we examined whether or not alkylphenols, bisphenol A, benzophenone, di(2-ethylhexyl)adipate and 10 phthalates are present in containers of baby food. Furthermore, the migration into food-simulating solvents was also examined. Sixteen types of containers of baby food, obtained on the Japanese market in 2001, were examined: 8 glass bottle types, 1 plastic type, 1 metallic package (laminated with plastic) and 6 multilayered laminated film packages. Alkylphenols, benzophenone, bisphenol A and di(2-ethylhexyl)adipate were not detected in any of the samples. On the other hand, dibutylphthalate (DBP) was detected in 7 samples (1.2-9.1 micrograms/sample), and di(2-ethylhexyl)phthalate (DEHP) was detected in 15 samples (1.3-18 micrograms/sample). Migration tests were carried out for 5 samples, and the levels of DBP and DEHP that migrated into n-heptane were 0.68-1.7 micrograms/sample and 0.33-3.5 micrograms/sample, respectively. From these results, a baby's intake levels of DBP and DEHP were estimated to be about 1/2,500 and 1/90-300 of the tolerable daily intake (TDI), respectively. 相似文献
64.
Kawai K. Koike K. Takei Y. Onozawa A. Obara H. Ichino H. 《Solid-State Circuits, IEEE Journal of》1999,34(1):12-17
A regenerator-section terminating digital large-scale-integration chip for an STM-16 (2.5-Gbit/s synchronous optical network/synchronous digital hierarchy) regenerator has been developed using low-power bipolar technologies. The high-speed performance of bipolar devices enabled four or more chips, including a demultiplexer and a multiplexer, to be integrated into a single chip. The low-power dissipation of 557 mW, only about one-tenth that of previously reported chips, was achieved through the use of four design steps: one-chip integration architecture, power management, 2.5-V emitter-coupled logic, and power optimization 相似文献
65.
66.
Takeshi Watanabe Tomoko K. Shimizu Yoshitaka Tateyama Yousoo Kim Maki Kawai Yasuaki Einaga 《Diamond and Related Materials》2010,19(7-9):772-777
The physical and electrochemical properties of boron-doped polycrystalline diamond electrodes, prepared with various B/C ratio, i.e., 0.1%, 0.5% (BDD-A), 1% (BDD-B), and 5% (BDD-C), were investigated. Electrochemical measurements of the heavily boron-doped films (BDD-C) showed giant electric double-layer capacitance and activity which is significantly larger than BDD-A and BDD-B as well as glassy carbon electrodes. However, interestingly, actual boron concentration of BDD-C was observed to be almost the same as that of BDD-B by secondary ion mass spectroscopy (SIMS) and glow discharge optical emission spectroscopy (GDOES) analysis. It is suggested that the large capacitance is due to a few sp2-bonded carbon impurities, which was observed only in BDD-C, although the amount of the sp2-bonded nondiamond species are very small. In the present work, the reason for the interesting electrochemical properties of heavily boron-doped diamond electrodes is discussed. Furthermore, dimensional stability of the electrodes was also confirmed by conducting harsh anodic treatment. 相似文献
67.
A. Sakaguchi K. Kawai F. Quinto J. Tomita N. Whitehead 《The Science of the total environment》2009,407(14):4238-4242
The global fallout 236U level in soil was deduced from measurements of 236U, 239+240Pu and 137Cs in surface soils which are solely influenced by global fallout. A total of 12 soil cores from the depths of 0-10, 0-20 and 0-30 cm were collected at a flat forest area in Japan. Concentrations of 239+240Pu and 238U were determined by α-particle spectrometry, while the 236U/238U ratio was measured with accelerator mass spectrometry (AMS). Consistent 236U/239Pu ratios between 0.212 and 0.253 were found. Using this ratio, the total global fallout of 236U on the earth is estimated to be as much as ca. 900 kg. This knowledge will contribute to the promotion of research on U isotopes, including 236U, for the fields of geo-resources, waste management and geochemistry. 相似文献
68.
Barakat S.M. Mahmoud Y. Kawai K. Yamazaki K. Miyashita T. Suzuki 《Food chemistry》2007,101(4):1492-1498
This investigation was undertaken to evaluate the effect of treatment with electrolyzed NaCl solutions and 1% essential oil (0.5% carvacrol + 0.5% thymol) on the proximate composition and nutritional components (amino acids and fatty acids) of carp fillets at room temperature (25 °C). Carp fillet samples were treated with anodic electrolyzed NaCl solution [EW (+)], cathodic electrolyzed NaCl solution [EW (−)] followed by EW (+) [EW (−)/EW (+)], 1% essential oil (0.5% carvacrol + 0.5% thymol) [1% (Cv + Ty)], EW (+) followed by 1% (Cv + Ty) [EW (+)/1% (Cv + Ty)] and EW (−) followed by EW (+) and finally with 1% (Cv + Ty) [EW (−)/EW (+)/1% (Cv + Ty)]. Proximate composition, SDS–PAGE, amino acid composition, digestibility and fatty acid composition were used to determine the changes in carp fillet composition. Moisture, total lipid, total protein, ash and carbohydrate contents of the carp fillets were approximately 76%, 3.9%, 17.5%, 1.0% and 0.40%, respectively. The dominant amino acid was glutamic acid, and the composition ranged from 14.2 to 14.5 mol%. Protein digestibility of the carp fillets was approximately 85%. Oleic acid was the major monounsaturated acid in the carp fillets (41.0–41.9%). These results show that our method of fish preservation, using electrolyzed NaCl solutions and 1% (Cv + Ty), did not affect the quality (nutritional components) of carp fillets, and could be a good alternative to synthetic preservatives routinely used in the food industry. 相似文献
69.
To clarify the relative importance of clinicopathological factors potentially affecting the survival of individuals initially diagnosed as having metastatic renal cell carcinoma (RCC), univariate and multivariate analyses using Cox's proportional hazards model were performed for 111 RCC patients who were admitted to four hospitals in Nagoya, Japan, between 1978 and 1993. Survival time was calculated from the date of diagnosis to the date of death or the end of May, 1995. Nineteen factors (17 clinically applicable before treatment and 2 histological in nature) were included for assessment. Univariate analysis revealed that 10 of the total 19 factors were significantly associated with patient survival. Multivariate analysis found 7 factors to be statistically significant determinants. Survival was further evaluated by categorizing the patients into three groups according to the number of the 7 factors. These groups showed clearly different survivals (log-rank test, p < 0.0001), confirming the importance of the 7 factors as definite determinants. They should therefore prove to be of advantage for classifying metastatic RCC patients when designing clinical prospective studies of immunotherapy and chemotherapy. 相似文献
70.
Orbital hydatid cyst is rare. We present a case with CT and MRI, emphasizing the superiority of the latter. 相似文献