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排序方式: 共有209条查询结果,搜索用时 31 毫秒
201.
Catherine Dorion Robert Chênevert Lucille Lacoste Jacques Lapointe 《Bioorganic & medicinal chemistry letters》1993,3(12):2699-2702
A specific inhibitor of glutamyl-tRNA synthetase, analog of glutamyl-adenylate, the N6-benzoyl-L-glutamol AMP, has been synthesized. This compound does not inhibit glutaminyl-tRNA synthetase. 相似文献
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203.
Vaishali Katju Lucille B. Packard Lijing Bu Peter D. Keightley Ulfar Bergthorsson 《Evolution; international journal of organic evolution》2015,69(1):104-116
The rate and fitness effects of new mutations have been investigated by mutation accumulation (MA) experiments in which organisms are maintained at a constant minimal population size to facilitate the accumulation of mutations with minimal efficacy of selection. We evolved 35 MA lines of Caenorhabditis elegans in parallel for 409 generations at three population sizes (N = 1, 10, and 100), representing the first spontaneous long-term MA experiment at varying population sizes with corresponding differences in the efficacy of selection. Productivity and survivorship in the N = 1 lines declined by 44% and 12%, respectively. The average effects of deleterious mutations in N = 1 lines are estimated to be 16.4% for productivity and 11.8% for survivorship. Larger populations (N = 10 and 100) did not suffer a significant decline in fitness traits despite a lengthy and sustained regime of consecutive bottlenecks exceeding 400 generations. Together, these results suggest that fitness decline in very small populations is dominated by mutations with large deleterious effects. It is possible that the MA lines at larger population sizes contain a load of cryptic deleterious mutations of small to moderate effects that would be revealed in more challenging environments. 相似文献
204.
Michael S. Clegg Carl L. Keen Bo Lönnerdal Lucille S. Hurley 《Biological trace element research》1981,3(2):107-115
A multitude of methods exists at present for the solubilization of biological tissues for atomic absorption analysis. We have examined several common methods of wet ashing using NBS bovine liver in order to determine which acids, acid combinations, or bases should be used as digesting agents for accurate and precise measurement of iron, copper, zinc, and manganese. Nitric acid proved to be the most effective wet ashing agent. With nitric acid, mean concentrations for iron, copper, and zinc differed from NBS certified values by less than 1.5% while those for manganese differed by 4%. 相似文献
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206.
Jane Dunham R. A. Dodds A. M. Nahir G. T. B. Frost A. Catterall Lucille Bitensky J. Chayen 《Cell biochemistry and function》1983,1(3):168-172
The apparent paradox of aerobic glycolysis has been investigated in bone and in cartilage. A new cytochemical procedure for hydroxyacyl dehydrogenase (HOAD) activity showed that the maximal activity of this enzyme in both tissues was equivalent to the maximal activity of glyceraldehyde 3-phosphate dehydrogenase (GAPD). The sum of these activities gave a measure of the maximum amount of acetyl-coenzyme A that could be produced. In these tissues, but not in liver which does not exhibit aerobic glycolysis, this summed value exceeded the maximal activity of succinate dehydrogenase (SDH). Consequently, it suggested that where fatty acid oxidation is sufficient to supply all the acetyl-coenzyme A required for the Krebs' cycle, that derived from fatty acid oxidation may inhibit pyruvate dehydrogenase causing accumulation of pyruvate which must be converted to lactate if pentose-shunt activity is to be maintained. 相似文献
207.
Parker Hughes Lucille J. Rudman Matthew Schrader 《Journal of evolutionary biology》2023,36(6):874-881
Inbreeding depression occurs when individuals who are closely related mate and produce offspring with reduced fitness. Although inbreeding depression is a genetic phenomenon, the magnitude of inbreeding depression can be influenced by environmental conditions and parental effects. In this study, we tested whether size-based parental effects influence the magnitude of inbreeding depression in an insect with elaborate and obligate parental care (the burying beetle, Nicrophorus orbicollis). We found that larger parents produced larger offspring. However, larval mass was also influenced by the interaction between parental body size and larval inbreeding status: when parents were small, inbred larvae were smaller than outbred larvae, but when parents were large this pattern was reversed. In contrast, survival from larval dispersal to adult emergence showed inbreeding depression that was unaffected by parental body size. Our results suggest that size-based parental effects can generate variation in the magnitude of inbreeding depression. Further work is needed to dissect the mechanisms through which this might occur and to better understand why parental size influences inbreeding depression in some traits but not others. 相似文献
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209.
Lucille A. Sherlick 《American anthropologist》1997,99(1):151-153
AIDS and Intravenous Drug Use: The Influence of Morality, Politics, Social Science, and Race in the Making of. Tragedy. M. Daniel Fernando. Westport, CT: Praeger Publishers, 1993.167 pp. 相似文献