全文获取类型
收费全文 | 82篇 |
免费 | 6篇 |
专业分类
88篇 |
出版年
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 1篇 |
2015年 | 3篇 |
2014年 | 1篇 |
2013年 | 3篇 |
2012年 | 2篇 |
2011年 | 1篇 |
2010年 | 1篇 |
2009年 | 3篇 |
2008年 | 1篇 |
2007年 | 2篇 |
2006年 | 2篇 |
2005年 | 3篇 |
2004年 | 2篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1975年 | 5篇 |
1974年 | 1篇 |
1973年 | 3篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1969年 | 1篇 |
1968年 | 6篇 |
1967年 | 2篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1960年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有88条查询结果,搜索用时 0 毫秒
21.
R Simões WB Feitosa CM Mendes AC Nicacio FRO de Barros 《Biotechnic & histochemistry》2013,88(3):79-83
Sperm chromatin integrity is essential for accurate transmission of male genetic information, and normal sperm chromatin structure is important for fertilization. Protamine is a nuclear protein that plays a key role in sperm DNA integrity, because it is responsible for sperm DNA stability and packing until the paternal genome is delivered into the oocyte during fertilization. Our aim was to investigate protamine deficiency in sperm cells of Bos indicus bulls (Nelore) using chromomycin A3 (CMA3) staining. Frozen semen from 14 bulls were thawed, then fixed in Carnoy's solution. Smears were prepared and analyzed by microscopy. As a positive control of CMA3 staining, sperm from one bull was subjected to deprotamination of nuclei. The percentage of CMA3-positive bovine sperm did not vary among batches. Only two bulls showed a higher percentage of CMA3-positive sperm cells compared to the others. CMA3 is a simple and useful tool for detecting sperm protamine deficiency in bulls. 相似文献
22.
Enzymatic conjugation of epoxides with glutathione 总被引:15,自引:0,他引:15
T A Fjellstedt R H Allen B K Duncan W B Jakoby 《The Journal of biological chemistry》1973,248(10):3702-3707
23.
24.
Tartaric acid metabolism. 3. The formation of glyceric acid 总被引:3,自引:0,他引:3
25.
Yeast alcohol dehydrogenase is an example of a protein in which the K-m for substrate is substantially decreased by the presence of glycerol. The polyol has the effect at pH 8.0 or above of decreasing K-m and K-s for substrate and of altering both the protein's intrinsic fluorescence and ultraviolet absorption difference spectrum. The relationship between each of thse parameters and glycerol concentration displays a transition at a glycerol concentration of 20%. Circular dichroism values for the enzyme are not affected by glycerol over a large range of concentration and temperature. Treatment of the enzyme with glutaraldehyde results in the formation of cross-linked tetramers, the K-m of which are not altered by the presence of the solvent. The data are interpreted as reflecting a change in the conformation of the protein induced by glycerol. 相似文献
26.
27.
28.
Ordered binding of substrates to yeast aldehyde dehydrogenase 总被引:4,自引:0,他引:4
29.
Joyce S. Myers William B. Jakoby 《Biochemical and biophysical research communications》1973,51(3):631-636
The effect of glycerol and other polyhydric compounds on the kinetic parameters of sixteen enzymes has been investigated. Substantial changes in Km and turnover rate were observed. Kinetic values obtained depended on pH as well as on the specific polyhydric compound added and its concentration. No pattern in direction or extent of change in kinetic constants was evident. 相似文献
30.