全文获取类型
收费全文 | 892篇 |
免费 | 200篇 |
专业分类
1092篇 |
出版年
2016年 | 11篇 |
2015年 | 18篇 |
2014年 | 26篇 |
2013年 | 23篇 |
2012年 | 32篇 |
2011年 | 41篇 |
2010年 | 23篇 |
2009年 | 18篇 |
2008年 | 37篇 |
2007年 | 29篇 |
2006年 | 37篇 |
2005年 | 29篇 |
2004年 | 38篇 |
2003年 | 36篇 |
2002年 | 27篇 |
2001年 | 31篇 |
2000年 | 27篇 |
1999年 | 24篇 |
1998年 | 13篇 |
1997年 | 16篇 |
1996年 | 19篇 |
1995年 | 19篇 |
1994年 | 12篇 |
1993年 | 11篇 |
1992年 | 23篇 |
1991年 | 23篇 |
1990年 | 21篇 |
1989年 | 24篇 |
1988年 | 23篇 |
1987年 | 18篇 |
1986年 | 20篇 |
1985年 | 19篇 |
1984年 | 15篇 |
1983年 | 13篇 |
1982年 | 15篇 |
1981年 | 19篇 |
1980年 | 20篇 |
1979年 | 17篇 |
1977年 | 18篇 |
1976年 | 11篇 |
1975年 | 18篇 |
1974年 | 7篇 |
1973年 | 22篇 |
1972年 | 9篇 |
1971年 | 22篇 |
1970年 | 8篇 |
1969年 | 7篇 |
1968年 | 8篇 |
1967年 | 6篇 |
1965年 | 12篇 |
排序方式: 共有1092条查询结果,搜索用时 15 毫秒
21.
22.
23.
24.
25.
26.
27.
28.
29.
A complex pattern of H2A phosphorylation in the mouse testis 总被引:1,自引:0,他引:1
Phosphorylation of H2A histones in mouse testis was examined using testis tubule cultures labeled with 32PO4. Histones were analyzed by two systems of two-dimensional polyacrylamide gel electrophoresis, followed by autoradiography of the gels. Of the 32PO4 detected in histones, 95% was incorporated by certain modified forms of the H2A variants H2A.1 and H2A.X. Phosphorylation sites were mapped to N- and C-terminal regions of the modified variants by SDS gel electrophoresis and autoradiography of peptides generated by cleavage of in vitro-labeled proteins with N-bromosuccinimide. Incorporation rates differed for N- and C-terminal regions from different modified forms, demonstrating a complex pattern of H2A phosphorylation in the mouse testis. 相似文献
30.
Substrate Specificity of the H-Sucrose Symporter on the Plasma Membrane of Sugar Beets (Beta vulgaris L.) : Transport of Phenylglucopyranosides 下载免费PDF全文
Previous results (TJ Buckhout, Planta [1989] 178: 393-399) indicated that the structural specificity of the H+-sucrose symporter on the plasma membrane from sugar beet leaves (Beta vulgaris L.) was specific for the sucrose molecule. To better understand the structural features of the sucrose molecule involved in its recognition by the symport carrier, the inhibitory activity of a variety of phenylhexopyranosides on sucrose uptake was tested. Three competitive inhibitors of sucrose uptake were found, phenyl-α-d-glucopyranoside, phenyl-α-d-thioglucopyranoside, and phenyl-α-d-4-deoxythioglucopyranoside (PDTGP; Ki = 67, 180, and 327 micromolar, respectively). The Km for sucrose uptake was approximately 500 micromolar. Like sucrose, phenyl-α-d-thioglucopyranoside and to a lesser extent, PDTGP induced alkalization of the external medium, which indicated that these derivatives bound to and were transported by the sucrose symporter. Phenyl-α-d-3-deoxy-3-fluorothioglucopyranoside, phenyl-α-d-4-deoxy-4-fluorothioglucopyranoside, and phenyl-α-d-thioallopyranoside only weakly but competively inhibited sucrose uptake with Ki values ranging from 600 to 800 micromolar, and phenyl-α-d-thiomannopyranoside, phenyl-β-d-glucopyranoside, and phenylethyl-β-d-thiogalactopyranoside did not inhibit sucrose uptake. Thus, the hydroxyl groups of the fructose portion of sucrose were not involved in a specific interaction with the carrier protein because phenyl and thiophenyl derivatives of glucose inhibited sucrose uptake and, in the case of phenyl-α-d-thioglucopyranoside and PDTGP, were transported. 相似文献