全文获取类型
收费全文 | 13168篇 |
免费 | 1185篇 |
国内免费 | 7篇 |
出版年
2023年 | 87篇 |
2022年 | 154篇 |
2021年 | 422篇 |
2020年 | 221篇 |
2019年 | 262篇 |
2018年 | 346篇 |
2017年 | 299篇 |
2016年 | 490篇 |
2015年 | 780篇 |
2014年 | 841篇 |
2013年 | 1005篇 |
2012年 | 1104篇 |
2011年 | 1180篇 |
2010年 | 741篇 |
2009年 | 569篇 |
2008年 | 820篇 |
2007年 | 784篇 |
2006年 | 668篇 |
2005年 | 628篇 |
2004年 | 568篇 |
2003年 | 477篇 |
2002年 | 444篇 |
2001年 | 110篇 |
2000年 | 92篇 |
1999年 | 93篇 |
1998年 | 90篇 |
1997年 | 75篇 |
1996年 | 68篇 |
1995年 | 79篇 |
1994年 | 59篇 |
1993年 | 49篇 |
1992年 | 43篇 |
1991年 | 48篇 |
1990年 | 46篇 |
1989年 | 37篇 |
1988年 | 34篇 |
1987年 | 33篇 |
1986年 | 30篇 |
1985年 | 32篇 |
1984年 | 54篇 |
1983年 | 31篇 |
1982年 | 22篇 |
1981年 | 27篇 |
1980年 | 18篇 |
1978年 | 20篇 |
1977年 | 24篇 |
1976年 | 21篇 |
1975年 | 26篇 |
1974年 | 16篇 |
1970年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Zhaolin Wang Cara Fraley Adam R. Mezo 《Bioorganic & medicinal chemistry letters》2013,23(5):1253-1256
The neonatal Fc receptor, FcRn, prolongs the half-life of IgG in the serum and represents a potential therapeutic target for the treatment of autoimmune disease. Small molecules that block the protein–protein interactions of human IgG–human FcRn may lower pathogenic autoantibodies and provide effective treatment. A novel class of quinoxalines has been discovered as antagonists of the IgG:FcRn protein–protein interaction through optimization of a hit derived from a virtual ligand-based screen. 相似文献
2.
3.
Plant and Soil - Cracks and biopores in compacted soil such as plough pans could aid deep rooting, mitigating constraints to seasonal upland use of paddy fields for rice production. This research... 相似文献
4.
5.
6.
Hierarchy and monophyly 总被引:1,自引:0,他引:1
7.
Eliot C. Bush Anne E. Clark Chris M. DeBoever Lillian E. Haynes Sidra Hussain Singer Ma Matthew M. McDermott Adam M. Novak John S. Wentworth 《PloS one》2012,7(11)
A significant proportion of enzymes display cooperativity in binding ligand molecules, and such effects have an important impact on metabolic regulation. This is easiest to understand in the case of positive cooperativity. Sharp responses to changes in metabolite concentrations can allow organisms to better respond to environmental changes and maintain metabolic homeostasis. However, despite the fact that negative cooperativity is almost as common as positive, it has been harder to imagine what advantages it provides. Here we use computational models to explore the utility of negative cooperativity in one particular context: that of an inhibitor binding to an enzyme. We identify several factors which may contribute, and show that acting together they can make negative cooperativity advantageous. 相似文献
8.
Nina Boiko Volodymyr Kucher Benjamin A. Eaton James D. Stockand 《The Journal of biological chemistry》2013,288(13):9418-9427
The voltage-gated K+ (Kv) channel blocker 4-aminopyridine (4-AP) is used to target symptoms of the neuroinflammatory disease multiple sclerosis (MS). By blocking Kv channels, 4-AP facilitates action potential conduction and neurotransmitter release in presynaptic neurons, lessening the effects of demyelination. Because they conduct inward Na+ and Ca2+ currents that contribute to axonal degeneration in response to inflammatory conditions, acid-sensing ion channels (ASICs) contribute to the pathology of MS. Consequently, ASICs are emerging as disease-modifying targets in MS. Surprisingly, as first demonstrated here, 4-AP inhibits neuronal degenerin/epithelial Na+ (Deg/ENaC) channels, including ASIC and BLINaC. This effect is specific for 4-AP compared with its heterocyclic base, pyridine, and the related derivative, 4-methylpyridine; and akin to the actions of 4-AP on the structurally unrelated Kv channels, dose- and voltage-dependent. 4-AP has differential actions on distinct ASICs, strongly inhibiting ASIC1a channels expressed in central neurons but being without effect on ASIC3, which is enriched in peripheral sensory neurons. The voltage dependence of the 4-AP block and the single binding site for this inhibitor are consistent with 4-AP binding in the pore of Deg/ENaC channels as it does Kv channels, suggesting a similar mechanism of inhibition in these two classes of channels. These findings argue that effects on both Kv and Deg/ENaC channels should be considered when evaluating the actions of 4-AP. Importantly, the current results are consistent with 4-AP influencing the symptoms of MS as well as the course of the disease because of inhibitory actions on Kv and ASIC channels, respectively. 相似文献
9.
A Adam J Damas P Franchimont 《Comptes rendus des séances de la Société de biologie et de ses filiales》1980,174(5):856-862
A radioimmunoassay for low molecular weight (LMW) human Kininogen has been carried out. The first step was to prepare LMW Kininogen from human plasma. The proposed method allowed to get chemically pure and biologically active LMW Kininogen. This preparation was used to induce antibody. Optimal conditions for labelling and incubation were determined. This method may be applied to the assay of Kininogen in human plasma. 相似文献
10.