全文获取类型
收费全文 | 5086篇 |
免费 | 416篇 |
国内免费 | 1篇 |
出版年
2023年 | 15篇 |
2021年 | 78篇 |
2020年 | 42篇 |
2019年 | 64篇 |
2018年 | 72篇 |
2017年 | 73篇 |
2016年 | 135篇 |
2015年 | 184篇 |
2014年 | 236篇 |
2013年 | 294篇 |
2012年 | 330篇 |
2011年 | 325篇 |
2010年 | 255篇 |
2009年 | 202篇 |
2008年 | 287篇 |
2007年 | 288篇 |
2006年 | 248篇 |
2005年 | 266篇 |
2004年 | 264篇 |
2003年 | 262篇 |
2002年 | 244篇 |
2001年 | 92篇 |
2000年 | 77篇 |
1999年 | 85篇 |
1998年 | 91篇 |
1997年 | 48篇 |
1996年 | 32篇 |
1995年 | 41篇 |
1994年 | 41篇 |
1993年 | 39篇 |
1992年 | 66篇 |
1991年 | 60篇 |
1990年 | 48篇 |
1989年 | 45篇 |
1988年 | 40篇 |
1987年 | 33篇 |
1986年 | 24篇 |
1985年 | 30篇 |
1984年 | 28篇 |
1983年 | 24篇 |
1982年 | 31篇 |
1981年 | 27篇 |
1980年 | 15篇 |
1979年 | 16篇 |
1978年 | 17篇 |
1977年 | 16篇 |
1976年 | 15篇 |
1974年 | 20篇 |
1973年 | 18篇 |
1972年 | 14篇 |
排序方式: 共有5503条查询结果,搜索用时 0 毫秒
1.
The oxidants of the SH groups (o-iodozobenzoate, oxidized glutathione, etc.) and the divalent cations of some metals (Zn2+ and Cd2+) significantly slow down the rate of inactivation by the protein inhibitor of the isolated F1-ATPase and ATPase in submitochondrial particles. Modification of SH groups in the ATPase does not change the rate of inactivation but completely prevents the effect of oxidants. 相似文献
2.
3.
4.
5.
6.
Denis Williams 《BMJ (Clinical research ed.)》1964,2(5424):1554-1557
7.
8.
9.
C Bailly J P Catteau N Helbecque J L Bernier R Houssin C Denis J P Hénichart 《Journal of inorganic biochemistry》1987,31(3):211-220
A model incorporating the metal chelating moiety of bleomycin and an anilinoacridine ring able to intercalate in DNA has been synthesized. The copper(II) complex of that molecule has been studied using circular dichroism and electron spin resonance by comparison with bleomycin. The introduction of the anilinoacridine ring involves a modification in the geometry of the complex. A distortion of the square-pyramidal form (type II complex) gives rise to a type I complex in which the metallic atom is drawn out of the plane of the four square-planar ligands and displaced slightly towards the fifth ligand. 相似文献
10.
The primary structure of the beta-subunit of the cell surface adhesion glycoproteins LFA-1, CR3 and p150,95 and its relationship to the fibronectin receptor. 总被引:33,自引:6,他引:27 下载免费PDF全文
The lymphocyte-function-associated antigen-1 (LFA-1), the complement receptor type 3 (CR3) and the antigen p150,95 are cell-surface glycoproteins. They are heterodimeric complexes, each containing a unique alpha-subunit noncovalently associated with a common beta-subunit. We have purified the beta-subunit from human spleen and obtained limited peptide sequences. What appears to be the complete primary structure for the fully processed beta-subunit was obtained by cDNA sequencing of clones from a phorbol ester (PMA) stimulated U937 cDNA library. There are five possible glycosylation sites and a transmembrane segment. The sequence contains a high level of cysteine (7.6%), with 24 of the 57 cysteine residues being found in three repeating units each with eight residues. The entire primary structure has 47% identity to a subunit of a fibronectin binding protein from chicken fibroblasts. It seems that LFA-1, CR3 and p150,95 antigens may belong to an extended family of cell surface molecules including the fibronectin binding protein. 相似文献