全文获取类型
收费全文 | 80篇 |
免费 | 2篇 |
专业分类
林业 | 7篇 |
农学 | 6篇 |
基础科学 | 3篇 |
18篇 | |
综合类 | 19篇 |
畜牧兽医 | 17篇 |
园艺 | 3篇 |
植物保护 | 9篇 |
出版年
2023年 | 2篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 1篇 |
2012年 | 3篇 |
2011年 | 7篇 |
2010年 | 4篇 |
2009年 | 6篇 |
2008年 | 3篇 |
2007年 | 2篇 |
2006年 | 7篇 |
2005年 | 5篇 |
2004年 | 5篇 |
2003年 | 5篇 |
2002年 | 6篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1983年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1952年 | 1篇 |
排序方式: 共有82条查询结果,搜索用时 62 毫秒
81.
Shima S Pilak O Vogt S Schick M Stagni MS Meyer-Klaucke W Warkentin E Thauer RK Ermler U 《Science (New York, N.Y.)》2008,321(5888):572-575
Biological formation and consumption of molecular hydrogen (H2) are catalyzed by hydrogenases, of which three phylogenetically unrelated types are known: [NiFe]-hydrogenases, [FeFe]-hydrogenases, and [Fe]-hydrogenase. We present a crystal structure of [Fe]-hydrogenase at 1.75 angstrom resolution, showing a mononuclear iron coordinated by the sulfur of cysteine 176, two carbon monoxide (CO) molecules, and the sp2-hybridized nitrogen of a 2-pyridinol compound with back-bonding properties similar to those of cyanide. The three-dimensional arrangement of the ligands is similar to that of thiolate, CO, and cyanide ligated to the low-spin iron in binuclear [NiFe]- and [FeFe]-hydrogenases, although the enzymes have evolved independently and the CO and cyanide ligands are not found in any other metalloenzyme. The related iron ligation pattern of hydrogenases exemplifies convergent evolution and presumably plays an essential role in H2 activation. This finding may stimulate the ongoing synthesis of catalysts that could substitute for platinum in applications such as fuel cells. 相似文献
82.
Activation of endothelial cell protease activated receptor 1 by the protein C pathway 总被引:1,自引:0,他引:1
The coagulant and inflammatory exacerbation in sepsis is counterbalanced by the protective protein C (PC) pathway. Activated PC (APC) was shown to use the endothelial cell PC receptor (EPCR) as a coreceptor for cleavage of protease activated receptor 1 (PAR1) on endothelial cells. Gene profiling demonstrated that PAR1 signaling could account for all APC-induced protective genes, including the immunomodulatory monocyte chemoattractant protein-1 (MCP-1), which was selectively induced by activation of PAR1, but not PAR2. Thus, the prototypical thrombin receptor is the target for EPCR-dependent APC signaling, suggesting a role for this receptor cascade in protection from sepsis. 相似文献