全文获取类型
收费全文 | 89篇 |
免费 | 0篇 |
专业分类
现状及发展 | 40篇 |
研究方法 | 14篇 |
综合类 | 35篇 |
出版年
2022年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 4篇 |
2015年 | 3篇 |
2013年 | 2篇 |
2012年 | 4篇 |
2011年 | 12篇 |
2010年 | 6篇 |
2009年 | 1篇 |
2008年 | 4篇 |
2007年 | 4篇 |
2006年 | 4篇 |
2005年 | 5篇 |
2004年 | 3篇 |
2003年 | 6篇 |
2002年 | 2篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1982年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1973年 | 2篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1964年 | 1篇 |
1962年 | 2篇 |
1959年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有89条查询结果,搜索用时 437 毫秒
41.
Direct generation of functional dopaminergic neurons from mouse and human fibroblasts 总被引:2,自引:0,他引:2
42.
Ratje AH Loerke J Mikolajka A Brünner M Hildebrand PW Starosta AL Dönhöfer A Connell SR Fucini P Mielke T Whitford PC Onuchic JN Yu Y Sanbonmatsu KY Hartmann RK Penczek PA Wilson DN Spahn CM 《Nature》2010,468(7324):713-716
The elongation cycle of protein synthesis involves the delivery of aminoacyl-transfer RNAs to the aminoacyl-tRNA-binding site (A?site) of the ribosome, followed by peptide-bond formation and translocation of the tRNAs through the ribosome to reopen the A?site. The translocation reaction is catalysed by elongation factor G (EF-G) in a GTP-dependent manner. Despite the availability of structures of various EF-G-ribosome complexes, the precise mechanism by which tRNAs move through the ribosome still remains unclear. Here we use multiparticle cryoelectron microscopy analysis to resolve two previously unseen subpopulations within Thermus thermophilus EF-G-ribosome complexes at subnanometre resolution, one of them with a partly translocated tRNA. Comparison of these substates reveals that translocation of tRNA on the 30S subunit parallels the swivelling of the 30S head and is coupled to unratcheting of the 30S body. Because the tRNA maintains contact with the peptidyl-tRNA-binding site (P?site) on the 30S head and simultaneously establishes interaction with the exit site (E?site) on the 30S platform, a novel intra-subunit 'pe/E' hybrid state is formed. This state is stabilized by domain?IV of EF-G, which interacts with the swivelled 30S-head conformation. These findings provide direct structural and mechanistic insight into the 'missing link' in terms of tRNA intermediates involved in the universally conserved translocation process. 相似文献
43.
The prolyl isomerase Pin1 reveals a mechanism to control p53 functions after genotoxic insults 总被引:5,自引:0,他引:5
Zacchi P Gostissa M Uchida T Salvagno C Avolio F Volinia S Ronai Z Blandino G Schneider C Del Sal G 《Nature》2002,419(6909):853-857
44.
45.
46.
Paola Gastaldo Paola Profumo Liliana Caffaro Corti 《Cellular and molecular life sciences : CMLS》1982,38(3):351-352
Summary Studies conducted onCercis siliquastrum seeds treated with kinetin confirm that this hormone does not interrupt dormancy in either whole seeds or those decoated at the radical pole. Seeds totally decoated or decoated at the cotyledon pole only demonstrated atypical germinations linked to cotyledon growth, permitting the embryo to escape the inhibitory action present in the endosperm; this does not occur when the cotyledon surface is experimentally reduced.This investigation was supported by the Italian National Research Council (C.N.R.) Project Biology of Reproduction. 相似文献
47.
CFTR channel opening by ATP-driven tight dimerization of its nucleotide-binding domains 总被引:1,自引:0,他引:1
ABC (ATP-binding cassette) proteins constitute a large family of membrane proteins that actively transport a broad range of substrates. Cystic fibrosis transmembrane conductance regulator (CFTR), the protein dysfunctional in cystic fibrosis, is unique among ABC proteins in that its transmembrane domains comprise an ion channel. Opening and closing of the pore have been linked to ATP binding and hydrolysis at CFTR's two nucleotide-binding domains, NBD1 and NBD2 (see, for example, refs 1, 2). Isolated NBDs of prokaryotic ABC proteins dimerize upon binding ATP, and hydrolysis of the ATP causes dimer dissociation. Here, using single-channel recording methods on intact CFTR molecules, we directly follow opening and closing of the channel gates, and relate these occurrences to ATP-mediated events in the NBDs. We find that energetic coupling between two CFTR residues, expected to lie on opposite sides of its predicted NBD1-NBD2 dimer interface, changes in concert with channel gating status. The two monitored side chains are independent of each other in closed channels but become coupled as the channels open. The results directly link ATP-driven tight dimerization of CFTR's cytoplasmic nucleotide-binding domains to opening of the ion channel in the transmembrane domains. This establishes a molecular mechanism, involving dynamic restructuring of the NBD dimer interface, that is probably common to all members of the ABC protein superfamily. 相似文献
48.
EPS8 and E3B1 transduce signals from Ras to Rac. 总被引:27,自引:0,他引:27
G Scita J Nordstrom R Carbone P Tenca G Giardina S Gutkind M Bjarneg?rd C Betsholtz P P Di Fiore 《Nature》1999,401(6750):290-293
The small guanine nucleotide (GTP)-binding protein Rac regulates mitogen-induced cytoskeletal changes and c-Jun amino-terminal kinase (JNK), and its activity is required for Ras-mediated cell transformation. Epistatic analysis placed Rac as a key downstream target in Ras signalling; however, the biochemical mechanism regulating the cross-talk among these small GTP-binding proteins remains to be elucidated. Eps8 (relative molecular mass 97,000) is a substrate of receptors with tyrosine kinase activity which binds, through its SH3 domain, to a protein designated E3b1/Abi-1. Here we show that Eps8 and E3b1/Abi-1 participate in the transduction of signals from Ras to Rac, by regulating Rac-specific guanine nucleotide exchange factor (GEF) activities. We also show that Eps8, E3b1 and Sos-1 form a tri-complex in vivo that exhibits Rac-specific GEF activity in vitro. We propose a model in which Eps8 mediates the transfer of signals between Ras and Rac, by forming a complex with E3b1 and Sos-1. 相似文献
49.
Elena Rapizzi Maria Letizia Taddei Tania Fiaschi Chiara Donati Paola Bruni Paola Chiarugi 《Cellular and molecular life sciences : CMLS》2009,66(19):3207-3218
Sphingosine 1-phosphate (S1P) is a bioactive lipid that acts through a family of G-protein-coupled receptors. Herein, we report
evidence of a novel redox-based cross-talk between S1P and insulin signaling pathways. In skeletal muscle cells S1P, through
engagement of its S1P2 receptor, is found to produce a transient burst of reactive oxygen species through a calcium-dependent activation of the
small GTPase Rac1. S1P-induced redox-signaling is sensed by protein tyrosine phosphatase-1B, the main negative regulator of
insulin receptor phosphorylation, which undergoes oxidation and enzymatic inhibition. This redox-based inhibition of the phosphatase
provokes a ligand-independent trans-phosphorylation of insulin receptor and a strong increase in glucose uptake. Our results propose a new role of S1P, recognizing
the lipid as an insulin-mimetic cue and pointing at reactive oxygen species as critical regulators of the cross-talk between
S1P and insulin pathways. Any possible implication of S1P-directed insulin signaling in diabetes and insulin resistance remains
to be established. 相似文献
50.