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961.
Ichiro Tayasu Riyo Hirasawa Nanako O. Ogawa Naohiko Ohkouchi Keita Yamada 《Limnology》2011,12(3):261-266
We determined both carbon and nitrogen isotope ratios of ten organic reference materials (CERKU-01 to CERKU-10) in the Center
for Ecological Research (CER), Kyoto University, and three organic reference materials (BG-A, BG-P, and BG-T) in the Institute
of Biogeosciences (BioGeos), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), using an internationally recommended
calibration method of two-point anchoring. The reference materials cover δ13CVPDB range of −34.92 to −9.45‰ and δ15NAir range of −5.22 to 22.71‰ and can be used to measure isotope ratios of naturally occurring substances. 相似文献
962.
Takaya Sugawara Tsubasa Furuhashi Kenji Shibata Masayuki Abe Keita Kikuchi Masato Arai 《Bioscience, biotechnology, and biochemistry》2019,83(8):1484-1489
ABSTRACTRice kefiran is superior in functionality, has high concentration of mucilaginous polysaccharide, and low lipid content, compared to conventional kefiran. However, reports on its physiological functionality, especially studies on life expectancy and aging, in model organisms are rare. In this study, nematodes were used as model organisms that were fed rice kefiran, along with Escherichia coli OP50, as a result of which, the lifespan of nematodes was extended and age-related retardation of mobility was suppressed. It also increased the heat stress resistance in nematodes. Experiments using daf-16 deletion mutant revealed that rice kefiran functions via DAF-16. Thus, this study revealed the longevity, anti-aging and heat stress tolerance effects of rice kefiran in nematodes. 相似文献
963.
We examined the catalytic action of L-methionine gamma-lyase (EC 4.4.1.11) on selenomethionine (2-amino-4-(methylseleno)butyric acid), methaneselenol, l-hexaneselenol, and benzeneselenol. The enzyme catalyzes alpha, gamma-elimination of selenomethionine to yield alpha-letobutyrate, ammonia, and methaneselenol, and also its gamma-replacement reaction with various thiols to produce S-substituted homocysteines. Selenomethionine is an even better substrate than methionine in alpha, gamma-elimination but is less effective in gamma-replacement. In addition, L-methionine gamma-lyase catalyzes gamma-replacement reaction of methionine and its derivatives with selenols to form the corresponding Se-substituted selenohomocysteines, although selenols are less efficient substituent donors than thiols. This is the first proven mechanism for the incorporation of selenium atom into amino acids. 相似文献
964.
965.
966.
Fukasawa Keita Mishima Yoshio Yoshioka Akira Kumada Nao Totsu Kumiko Osawa Takeshi 《Ecological Research》2016,31(4):493-493
In 2011, the Fukushima Daiichi Power Plant accident resulted in the evacuation of about 81,000 people from the evacuation zone, which suffered from high levels of radioactive contamination. Large-scale and long-term land abandonment can cause changes in species assemblages. Despite the extensive global attention this incident received, open and spatially-explicit datasets of mammal fauna from Fukushima remain quite limited. We established a continuous monitoring protocol using camera traps for mammals both inside and outside the evacuation zone; this paper presents our first dataset. These data represent the monitoring results from 45 camera traps from May 2014 to October 2014, including the location and actuation time of each camera, and the list of video records. After the publication of this initial data paper, we intend to continue monitoring until 2023 and the dataset will be hereafter updated with new observations. 相似文献
967.
B. Enanga C. Labat H. Boudra G. Chauvière M. Keita B. Bouteille M. Dumas G. Houin 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1997,696(2):213
A simple and sensitive high-performance liquid chromatographic method has been developed to measure megazol in human plasma. The method was optimized and validated according to the Washington Concensus Conference on the Validation of Analytical Methods (V.P. Shah et al., Eur. J. Drug Metab. Pharmacokinet., 15 (1991) 249). The criteria of complete validation were specificity, linearity, precision, analytical recovery, dilution and stability. It involved extraction of the plasma with dichloromethane, followed by reversed-phase high-performance liquid chromatography using a KromasilR C8 column and UV detection at 360 nm. The retention times of the internal standard (tinidazol) and megazol were 6.10 and 9.60 min, respevtively. The standard curve was linear from 2 ng ml−1 (limit of quantification) to 2000 ng ml−1. The coefficients of variation for all the criteria of validation were less than 6%; 85 to 92% extraction efficiencies were obtained. Megazol was stable during the storage period (one month at −20°C) in plasma and for two months at 25°C in standard solution. The method was tested by measuring the plasma concentration following oral administration to rat and was shown to be suitable for pharmacokinetic studies. 相似文献
968.
969.
Dependence of removal of sperm-specific proteins from Xenopus sperm nuclei on the phosphorylation state of nucleoplasmin 总被引:1,自引:0,他引:1
Keita Ohsumi Arata Shimada Eiichi Okumura Takeo Kishimoto Chiaki Katagiri 《Development, growth & differentiation》1995,37(3):329-336
In Xenopus laevis , nucleoplasmin from fully grown oocytes is not highly phosphorylated, but is more extensively phosphorylated during oocyte maturation to retain this state until mid-blastula transition. Incubation of demembranated sperm with nucleoplasmin from oocytes or mature eggs revealed that egg nucleoplasmin is twice as potent as oocyte nucleoplasmin in removing sperm-specific basic proteins from chromatin (protamine-removing activity: PRA). Dephosphorylation of egg nucleoplasmin by alkaline phosphatase induced a remarkable decline of PRA in nucleoplasmin. Treatment of oocyte nucleoplasmin with cdc2 protein kinase induced an increase of the extent of phosphorylation, but to a level lower than that exhibited by egg nucleoplasmin, suggesting the involvement of other unspecified kinase(s) in phosphorylating nucleoplasmin during oocyte maturation. Incubation of sperm with cdc2 kinase induced selective phosphorylation of sperm-specific basic proteins, accompanied by their enhanced removal from sperm chromatin upon exposure to high-salt solutions. These results suggest that removal of sperm-specific basic proteins from sperm chromatin in fertilized eggs is facilitated by phosphorylation of both nucleoplasmin and sperm-specific basic proteins. 相似文献