全文获取类型
收费全文 | 3905篇 |
免费 | 273篇 |
国内免费 | 1篇 |
专业分类
4179篇 |
出版年
2022年 | 36篇 |
2021年 | 61篇 |
2020年 | 39篇 |
2019年 | 58篇 |
2018年 | 55篇 |
2017年 | 42篇 |
2016年 | 100篇 |
2015年 | 142篇 |
2014年 | 174篇 |
2013年 | 199篇 |
2012年 | 235篇 |
2011年 | 225篇 |
2010年 | 135篇 |
2009年 | 151篇 |
2008年 | 195篇 |
2007年 | 174篇 |
2006年 | 161篇 |
2005年 | 156篇 |
2004年 | 154篇 |
2003年 | 147篇 |
2002年 | 148篇 |
2001年 | 78篇 |
2000年 | 77篇 |
1999年 | 68篇 |
1998年 | 43篇 |
1997年 | 37篇 |
1996年 | 24篇 |
1995年 | 26篇 |
1994年 | 32篇 |
1993年 | 30篇 |
1992年 | 52篇 |
1991年 | 32篇 |
1990年 | 34篇 |
1989年 | 40篇 |
1988年 | 26篇 |
1987年 | 20篇 |
1986年 | 32篇 |
1985年 | 34篇 |
1984年 | 36篇 |
1982年 | 19篇 |
1979年 | 32篇 |
1978年 | 26篇 |
1977年 | 29篇 |
1976年 | 18篇 |
1975年 | 25篇 |
1973年 | 26篇 |
1972年 | 23篇 |
1971年 | 24篇 |
1970年 | 35篇 |
1967年 | 25篇 |
排序方式: 共有4179条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Christian Renz Silke Oeljeklaus S?ren Grinhagens Bettina Warscheid Nils Johnsson Thomas Gronemeyer 《PloS one》2016,11(2)
The septins are a conserved family of GTP-binding proteins that, in the baker''s yeast, assemble into a highly ordered array of filaments at the mother bud neck. These filaments undergo significant structural rearrangements during the cell cycle. We aimed at identifying key components that are involved in or regulate the transitions of the septins. By combining cell synchronization and quantitative affinity-purification mass-spectrometry, we performed a screen for specific interaction partners of the septins at three distinct stages of the cell cycle. A total of 83 interaction partners of the septins were assigned. Surprisingly, we detected DNA-interacting/nuclear proteins and proteins involved in ribosome biogenesis and protein synthesis predominantly present in alpha-factor arrested that do not display an assembled septin structure. Furthermore, two distinct sets of regulatory proteins that are specific for cells at S-phase with a stable septin collar or at mitosis with split septin rings were identified.Complementary methods like SPLIFF and immunoprecipitation allowed us to more exactly define the spatial and temporal characteristics of selected hits of the AP-MS screen. 相似文献
5.
Extracellular ATP and adenosine modulate tumor necrosis factor-induced lysis of L929 cells in the presence of actinomycin D 总被引:1,自引:0,他引:1
Extracellular ATP in concentrations of 0.5 to 2.5 mM modulates TNF-induced cytolysis of L929 cells in the presence of actinomycin D. When present throughout the entire assay period, it inhibits the TNF-induced cytolysis. ADP was less active whereas AMP and GTP were nonreactive. However, inhibition was also achieved by adenosine that was nearly as active as ATP. Yet, the inhibitory effect of ATP was not due to hydrolysis by ectoenzymes to form adenosine. Thus, the nonhydrolyzable ATP analogue adenyl(beta-gamma-methylendiphosphate) was equally effective in inhibiting TNF-induced cytolysis. Moreover, no conversion of ATP into adenosine was observed during the entire assay period. However, inhibition no longer occurred when the TNF and ATP containing medium was removed after 5 h and replaced by a fresh medium containing TNF and no ATP. We now observed substantial enhancement of the TNF-induced cytolysis by ATP. Finally, treatment with N6-(R-phenylisopropyl)adenosine or with aminophylline, which are thought to downregulate adenosine receptors and to prevent binding of ligands to adenosine receptors, respectively, abolishes adenosine and ATP-mediated inhibition. Again, substantial enhancement of the TNF-induced cytolysis was observed by ATP and only a minor effect by adenosine. The results together suggest that ATP interacts with purinoceptors on the plasma membrane and is capable to enhance and inhibit TNF-induced cytolysis under appropriate conditions. The outcome of the ATP-induced modulation may be influenced by adenosine receptors. 相似文献
6.
Michaela Ludolphs Daniela Schneeberger Tolga Soykan Jonas Sch?fer Theofilos Papadopoulos Nils Brose Hermann Schindelin Claudia Steinem 《The Journal of biological chemistry》2016,291(1):244-254
The regulatory protein collybistin (CB) recruits the receptor-scaffolding protein gephyrin to mammalian inhibitory glycinergic and GABAergic postsynaptic membranes in nerve cells. CB is tethered to the membrane via phosphoinositides. We developed an in vitro assay based on solid-supported 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine membranes doped with different phosphoinositides on silicon/silicon dioxide substrates to quantify the binding of various CB2 constructs using reflectometric interference spectroscopy. Based on adsorption isotherms, we obtained dissociation constants and binding capacities of the membranes. Our results show that full-length CB2 harboring the N-terminal Src homology 3 (SH3) domain (CB2SH3+) adopts a closed and autoinhibited conformation that largely prevents membrane binding. This autoinhibition is relieved upon introduction of the W24A/E262A mutation, which conformationally “opens” CB2SH3+ and allows the pleckstrin homology domain to properly bind lipids depending on the phosphoinositide species with a preference for phosphatidylinositol 3-monophosphate and phosphatidylinositol 4-monophosphate. This type of membrane tethering under the control of the release of the SH3 domain of CB is essential for regulating gephyrin clustering. 相似文献
7.
E Weidekamm E Bamberg D Brdiczka G Wildermuth F Macco W Lehmann R Weber 《Biochimica et biophysica acta》1977,464(2):442-447
The interaction of gramicidin A with dipalmitoyl phosphatidylcholine liposomes is investigated by Laser-Raman spectroscopy. As revealed by the methylene C-H stretching mode the phase transition of the hydrocarbon chains near 40 degree C is eliminated in the presence of gramicidin A. Liposomes prepared from a mixture of lecithin and cholesterol seem to be unaffected by gramicidin A and show only the normal broadened phase transition. 相似文献
8.
9.
10.
Nils G. A. Ekelund 《Archives of microbiology》1989,151(3):187-190
The effects of the calcium channel blockers, verapamil, diltiazem and lanthanum ions and the Ca2+ dependency on motility as well as the photophobic response (stop-response) of Gyrodinium dorsum were studied. At Ca2+ concentrations below 10-3 M, motility was inhibited. La3+ inhibits the stop-response, in contrast to verapamil and diltiazem. The only calcium channel blocker that increased the amount of non-motile cells was verapamil. The results indicate that motility are Ca2+ dependent and that the stop-responses of G. dorsum could be affected by extracellular Ca2+. Effects of the photosythesis inhibitor (DCMU) on the stop-response was also determined. With background light of different wavelength (614, 658 and 686 nm) the stop-response increased. DCMU inhibited this effect of background light. Negative results with the monoclonal antibody Pea-25 directed to phytochrome and the results with DCMU, indicate that the stop-response of G. dorsum is coupled to photosynthesis rather than to a phytochrome-like pigment. Oxygen evolution, but not cell movement, was completely inhibited by 10-6 M DCMU.Abbreviations DCMU
3-(3,4-dichlorophenyl)-1,1-methylurea
- DILT
diltiazem
- DMSO
dimethylsulfoxide
- SDS-PAGE
sodium dodecyl sulphate-polyacrylamide gel electrophoresis
- VER
verapamil 相似文献