全文获取类型
收费全文 | 4946篇 |
免费 | 570篇 |
出版年
2021年 | 112篇 |
2020年 | 57篇 |
2019年 | 67篇 |
2018年 | 83篇 |
2017年 | 71篇 |
2016年 | 95篇 |
2015年 | 166篇 |
2014年 | 185篇 |
2013年 | 210篇 |
2012年 | 241篇 |
2011年 | 259篇 |
2010年 | 154篇 |
2009年 | 110篇 |
2008年 | 218篇 |
2007年 | 204篇 |
2006年 | 175篇 |
2005年 | 168篇 |
2004年 | 153篇 |
2003年 | 145篇 |
2002年 | 154篇 |
2001年 | 119篇 |
2000年 | 145篇 |
1999年 | 115篇 |
1998年 | 60篇 |
1997年 | 49篇 |
1996年 | 49篇 |
1995年 | 45篇 |
1994年 | 44篇 |
1992年 | 77篇 |
1991年 | 82篇 |
1990年 | 95篇 |
1989年 | 95篇 |
1988年 | 76篇 |
1987年 | 87篇 |
1986年 | 70篇 |
1985年 | 86篇 |
1984年 | 66篇 |
1983年 | 53篇 |
1982年 | 49篇 |
1981年 | 48篇 |
1979年 | 56篇 |
1978年 | 50篇 |
1977年 | 46篇 |
1976年 | 45篇 |
1975年 | 57篇 |
1973年 | 55篇 |
1972年 | 66篇 |
1971年 | 43篇 |
1970年 | 50篇 |
1969年 | 41篇 |
排序方式: 共有5516条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
The assembly of high voltage-activated Ca2+ channels with different β subunits influences channel properties and possibly subcellular targeting. We studied β subunit expression in the somata and axon terminals of the magnocellular neurosecretory cells, which are located in the supraoptic nucleus (SON) and neurohypophysis, respectively. Antibodies directed against the 4 CaVβ subunits (CaVβ1-CaVβ4) were used for immunoblots and for immunostaining of slices of these two tissues. We found that all 4 β subunits are expressed in both locations, but that CaVβ2 had the highest relative expression in the neurohypophysis. These data suggest that the CaVβ2 subunit is selectively targeted to axon terminals and may play a role in targeting and/or regulating the properties of Ca2+ channels. 相似文献
15.
16.
17.
18.
19.
Ethan R. Block Michael A. Tolino Jennifer S. Lozano Kira L. Lathrop Rebecca S. Sullenberger Abigail R. Mazie Jes K. Klarlund 《Molecular biology of the cell》2010,21(13):2172-2181
The ability of epithelia to migrate and cover wounds is essential to maintaining their functions as physical barriers. Wounding induces many cues that may affect the transition to motility, including the immediate mechanical perturbation, release of material from broken cells, new interactions with adjacent extracellular matrix, and breakdown of physical separation of ligands from their receptors. Depending on the exact nature of wounds, some cues may be present only transiently or insignificantly. In many epithelia, activation of the epidermal growth factor receptor (EGFR) is a central event in induction of motility, and we find that its continuous activation is required for progression of healing of wounds in sheets of corneal epithelial cells. Here, we examine the hypothesis that edges, which are universally and continuously present in wounds, are a cue. Using a novel culture model we find that their presence is sufficient to cause activation of the EGFR and increased motility of cells in the absence of other cues. Edges that are bordered by agarose do not induce activation of the EGFR, indicating that activation is not due to loss of any specific type of cell–cell interaction but rather due to loss of physical constraints. 相似文献
20.
E. Welby Fisher 《BMJ (Clinical research ed.)》1919,1(3043):514-516