全文获取类型
收费全文 | 1781318篇 |
免费 | 177865篇 |
国内免费 | 2110篇 |
出版年
2021年 | 18487篇 |
2018年 | 19302篇 |
2017年 | 18056篇 |
2016年 | 29475篇 |
2015年 | 43894篇 |
2014年 | 52159篇 |
2013年 | 78491篇 |
2012年 | 52547篇 |
2011年 | 44442篇 |
2010年 | 48661篇 |
2009年 | 48532篇 |
2008年 | 41126篇 |
2007年 | 40116篇 |
2006年 | 42776篇 |
2005年 | 43056篇 |
2004年 | 42463篇 |
2003年 | 39452篇 |
2002年 | 37342篇 |
2001年 | 56606篇 |
2000年 | 54738篇 |
1999年 | 48417篇 |
1998年 | 28483篇 |
1997年 | 28538篇 |
1996年 | 27566篇 |
1995年 | 25725篇 |
1994年 | 25356篇 |
1993年 | 24816篇 |
1992年 | 41713篇 |
1991年 | 40068篇 |
1990年 | 38921篇 |
1989年 | 38922篇 |
1988年 | 35776篇 |
1987年 | 34539篇 |
1986年 | 32468篇 |
1985年 | 33955篇 |
1984年 | 31072篇 |
1983年 | 27325篇 |
1982年 | 25056篇 |
1981年 | 23626篇 |
1980年 | 22199篇 |
1979年 | 27858篇 |
1978年 | 24481篇 |
1977年 | 22886篇 |
1976年 | 21721篇 |
1975年 | 22386篇 |
1974年 | 23636篇 |
1973年 | 23746篇 |
1972年 | 20731篇 |
1971年 | 19207篇 |
1970年 | 16636篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
701.
James F. Richards Kulgite Lit Roland Fuca Catherine Bourgeault 《Biochemical and biophysical research communications》1981,99(4):1461-1467
Several species of ornithine decarboxylase were separated by chromatography of rat thymus and kidney extracts on DEAE-Sepharose CL-6B. One major and one minor species were absent from thymus of rats two hours after hormone treatment but otherwise, the elution profile was identical to thymus from control animals. The elution patterns of ODC activity in kidneys of rats treated 2.5 or 5 hours before sacrifice with dexamethasone differ from that of control kidney and from each other. Enzyme from kidneys early after hormone treatment is eluted earlier than enzyme from control tissue, while at 5 hours, the enzyme is eluted much later than in the control. This suggests that the hormone-induced activity is subsequently modified. 相似文献
702.
703.
704.
705.
Topography of the C terminus of cytochrome b5 tightly bound to dimyristoylphosphatidylcholine vesicles 总被引:1,自引:0,他引:1
Cytochrome b5 holoenzyme was bound asymmetrically in the tightly bound form to small unilamellar dimyristoylphosphatidylcholine vesicles. [3H]Taurine, a membrane-impermeant nucleophile, was added to the external medium and was then cross-linked to cytochrome carboxyl residues by the addition of a water-soluble carbodiimide. Nonpolar peptide was isolated after trypsin digestion of taurine-labeled apocytochrome b5 and contained 1.7-1.9 residues of taurine. The C-terminal tetrapeptide containing residues Thr130-Asn133 was generated by chymotryptic hydrolysis of radiolabeled nonpolar peptide and was purified by gel filtration and ion exchange chromatography. Amino acid analysis of the C-terminal tetrapeptide showed that about 1.6 mol of taurine was cross-linked per mol of peptide. When the experiment was performed with taurine trapped inside the vesicles, no cross-linking was observed. The results suggest that when cytochrome b5 holoenzyme is bound to vesicles in the tight binding form, the C terminus is located on the external surface of the vesicles. 相似文献
706.
707.
J F Searle 《BMJ (Clinical research ed.)》1984,288(6435):1998-1999
708.
709.
Sylvester J. T.; Harabin A. L.; Peake M. D.; Frank R. S. 《Journal of applied physiology》1980,49(5):820-825
710.