全文获取类型
收费全文 | 1014篇 |
免费 | 52篇 |
国内免费 | 1篇 |
出版年
2023年 | 6篇 |
2022年 | 8篇 |
2021年 | 27篇 |
2020年 | 15篇 |
2019年 | 17篇 |
2018年 | 23篇 |
2017年 | 13篇 |
2016年 | 23篇 |
2015年 | 46篇 |
2014年 | 63篇 |
2013年 | 80篇 |
2012年 | 87篇 |
2011年 | 74篇 |
2010年 | 49篇 |
2009年 | 52篇 |
2008年 | 57篇 |
2007年 | 58篇 |
2006年 | 48篇 |
2005年 | 47篇 |
2004年 | 22篇 |
2003年 | 32篇 |
2002年 | 36篇 |
2001年 | 9篇 |
2000年 | 11篇 |
1999年 | 17篇 |
1998年 | 6篇 |
1997年 | 5篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 3篇 |
1991年 | 9篇 |
1990年 | 4篇 |
1989年 | 16篇 |
1988年 | 5篇 |
1986年 | 6篇 |
1985年 | 9篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 8篇 |
1978年 | 3篇 |
1976年 | 3篇 |
1975年 | 5篇 |
1974年 | 5篇 |
1973年 | 3篇 |
1967年 | 2篇 |
1964年 | 3篇 |
排序方式: 共有1067条查询结果,搜索用时 171 毫秒
21.
以生菜(Lactuca sativa)种子为研究对象,通过不同时间的吸水处理分析其含水量变化,再通过程序降温处理,分析不同含水量种子发芽率的差异,以及脂肪酸合成有关基因(FAD2、FAD3、PPT、ELOVL)和冷调节基因ICE1的表达。结果表明,种子含水量随吸水时间增加而升高。程序降温至同样的低温冷冻条件下(-20℃、-22℃),吸水时间小于6 h的种子发芽率较高,而吸水8 h以上的种子发芽率显著降低。种子吸水8 h含水量处于饱和状态,在此状态下种子对低温较为敏感,说明含水量对种子耐冻性有影响。冷冻处理后生菜种子基因表达检测结果表明,脂肪酸去饱和酶基因(FAD2、FAD3)、蛋白质棕榈酰基硫脂酶相关基因(PPT)、长链脂肪酸延伸酶相关基因(ELOVL)的表达水平均随着种子含水量增加呈上升趋势,吸胀10 h的种子表达量最高,此时种子由于高含水量所受冷冻伤害最大。基因ICE1在冷冻处理种子中的表达也随着吸水时间增加而升高,在吸水10 h时种子中表达量到最高水平。综上,种子含水量越高,所受冷冻伤害越大。但种子在低温条件下具有一定的抗冷反应,可通过相关基因的过表达调控合成更多不饱和脂肪酸、抗冻蛋白等提高含水种子耐冻性。 相似文献
22.
It is known that tomato (Lycopersicon esculentum) contains bioactive compounds to combat type-2 diabetes. Therefore, it is of interest to document data from the molecular docking analysis of compounds from Lycopersicon esculentum with the insulin receptors to combat type-2 diabetes. We report the binding features of cinnamic acid, chlorogenic acid, gallic acid & glucoside with insulin receptors for further consideration. 相似文献
23.
Gupta Achla Gullapalli Srinivas Pan Hui Ramos-Ortolaza Dinah L. Hayward Michael D. Low Malcom J. Pintar John E. Devi Lakshmi A. Gomes Ivone 《Cellular and molecular neurobiology》2021,41(5):1103-1118
Cellular and Molecular Neurobiology - Activation of μ, δ, and κ opioid receptors by endogenous opioid peptides leads to the regulation of many emotional and physiological responses.... 相似文献
24.
Kamala L. Kumar B. Sathish Lakshmi P. V. Anantha 《Russian Journal of Bioorganic Chemistry》2021,47(1):166-173
Russian Journal of Bioorganic Chemistry - A series of novel carbazol-thiazolidinedione hybrid derivatives were designed, synthesised and screened for antimicrobial activity against gram-positive... 相似文献
25.
Singh Ashish K. Kolligundla Lakshmi P. Francis Justus Pasupulati Anil K. 《Journal of physiology and biochemistry》2021,77(2):193-203
Journal of Physiology and Biochemistry - Hypoxia-inducible factor1 (HIF1) plays a pivotal role in ensuring cells adapt to low-oxygen conditions. Depletion of oxygen, a co-substrate during... 相似文献
26.
27.
Anneleen Daemen Obi L Griffith Laura M Heiser Nicholas J Wang Oana M Enache Zachary Sanborn Francois Pepin Steffen Durinck James E Korkola Malachi Griffith Joe S Hur Nam Huh Jongsuk Chung Leslie Cope Mary Jo Fackler Christopher Umbricht Saraswati Sukumar Pankaj Seth Vikas P Sukhatme Lakshmi R Jakkula Yiling Lu Gordon B Mills Raymond J Cho Eric A Collisson Laura J van’t Veer Paul T Spellman Joe W Gray 《Genome biology》2013,14(10):R110
28.
Gaurav Bhatti Lakshmi Jayanthi Pamela VandeVord Yeshitila Gebremichael 《Journal of molecular modeling》2013,19(2):779-792
The unique conformation of the active site in calpains along with the implication of their role in several diseases has prompted widespread research interest in the scientific community. Structural studies devoted to m- and μ-calpains have proposed a two-stage calcium-dependent activation mechanism for calpains. In this work, we performed conventional and targeted molecular dynamics simulations to investigate global and local changes in the structure of the protease core of m-calpain upon calcium binding. Simulations were performed on the protease core of calcium free (pdbid: 1kfu) and calcium bound (pdbid: 3df0) m-calpain with and without the presence of calcium ions. Our results indicate that the inactive, open conformation of the protease core does not transform into the active, closed conformation simply upon removal of constraints from the neighbor domains. The role of other factors, including calcium binding and the subsequent formation of an Arg94–Glu305 inter-domain salt bridge and the change in the orientation of Trp288 side chain, in the activation of the protease core is elicited. 相似文献
29.
Nathan P. Coussens Ryo Hayashi Patrick H. Brown Lakshmi Balagopalan Andrea Balbo Itoro Akpan Jon C. D. Houtman Valarie A. Barr Peter Schuck Ettore Appella Lawrence E. Samelson 《Molecular and cellular biology》2013,33(21):4140-4151
The adapter molecules SLP-76 and LAT play central roles in T cell activation by recruiting enzymes and other adapters into multiprotein complexes that coordinate highly regulated signal transduction pathways. While many of the associated proteins have been characterized, less is known concerning the mechanisms of assembly for these dynamic and potentially heterogeneous signaling complexes. Following T cell receptor (TCR) stimulation, SLP-76 is found in structures called microclusters, which contain many signaling complexes. Previous studies showed that a mutation to the SLP-76 C-terminal SH2 domain nearly abolished SLP-76 microclusters, suggesting that the SH2 domain facilitates incorporation of signaling complexes into microclusters. S. C. Bunnell, A. L. Singer, D. I. Hong, B. H. Jacque, M. S. Jordan, M. C. Seminario, V. A. Barr, G. A. Koretzky, and L. E. Samelson, Mol. Cell. Biol., 26:7155–7166, 2006). Using biophysical methods, we demonstrate that the adapter, ADAP, contains three binding sites for SLP-76, and that multipoint binding to ADAP fragments oligomerizes the SLP-76 SH2 domain in vitro. These results were complemented with confocal imaging and functional studies of cells expressing ADAP with various mutations. Our results demonstrate that all three binding sites are critical for SLP-76 microcluster assembly, but any combination of two sites will partially induce microclusters. These data support a model whereby multipoint binding of SLP-76 to ADAP facilitates the assembly of SLP-76 microclusters. This model has implications for the regulation of SLP-76 and LAT microclusters and, as a result, T cell signaling. 相似文献
30.
Anita Tragler Lakshmi Srinivasan Olga Shenderova Melvin McClauren Donald W. Brenner 《Molecular simulation》2013,39(1-2):121-130
Abstract A novel simulation interface is being developed as an educational tool to help students better understand fundamentals of materials science. This interface makes use of virtual reality (VR) technology consisting of PC-based graphics and a force-feedback haptic device. Visualization of atomistic processes with simultaneous tactile sensation via the haptic provides a powerful method for understanding complex phenomena that are otherwise difficult to comprehend. Modules are described that allow students to interactively explore interatomic bonding and single-atom diffusion through materials. 相似文献