全文获取类型
收费全文 | 42647篇 |
免费 | 3851篇 |
国内免费 | 3366篇 |
学科分类
生物科学 | 49864篇 |
出版年
2024年 | 19篇 |
2023年 | 519篇 |
2022年 | 622篇 |
2021年 | 1967篇 |
2020年 | 1523篇 |
2019年 | 1900篇 |
2018年 | 1770篇 |
2017年 | 1333篇 |
2016年 | 1870篇 |
2015年 | 2856篇 |
2014年 | 3244篇 |
2013年 | 3450篇 |
2012年 | 3983篇 |
2011年 | 3549篇 |
2010年 | 2260篇 |
2009年 | 1977篇 |
2008年 | 2358篇 |
2007年 | 2080篇 |
2006年 | 1867篇 |
2005年 | 1595篇 |
2004年 | 1355篇 |
2003年 | 1264篇 |
2002年 | 1037篇 |
2001年 | 765篇 |
2000年 | 618篇 |
1999年 | 592篇 |
1998年 | 357篇 |
1997年 | 360篇 |
1996年 | 336篇 |
1995年 | 274篇 |
1994年 | 311篇 |
1993年 | 201篇 |
1992年 | 267篇 |
1991年 | 221篇 |
1990年 | 166篇 |
1989年 | 137篇 |
1988年 | 104篇 |
1987年 | 128篇 |
1986年 | 100篇 |
1985年 | 97篇 |
1984年 | 65篇 |
1983年 | 50篇 |
1982年 | 51篇 |
1981年 | 29篇 |
1980年 | 21篇 |
1979年 | 29篇 |
1978年 | 19篇 |
1975年 | 21篇 |
1974年 | 18篇 |
1972年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Ji Guo Su Xiao Ming Han Xiao Zhang Yan Xue Hou Jian Zhuo Zhu Yi Dong Wu 《Journal of biomolecular structure & dynamics》2016,34(3):560-571
Protein collective motions play a critical role in many biochemical processes. How to predict the functional motions and the related key residue interactions in proteins is important for our understanding in the mechanism of the biochemical processes. Normal mode analysis (NMA) of the elastic network model (ENM) is one of the effective approaches to investigate the structure-encoded motions in proteins. However, the motion modes revealed by the conventional NMA approach do not necessarily correspond to a specific function of protein. In the present work, a new analysis method was proposed to identify the motion modes responsible for a specific function of proteins and then predict the key residue interactions involved in the functional motions by using a perturbation approach. In our method, an internal coordinate that accounts for the specific function was introduced, and the Cartesian coordinate space was transformed into the internal/Cartesian space by using linear approximation, where the introduced internal coordinate serves as one of the axes of the coordinate space. NMA of ENM in this internal/Cartesian space was performed and the function-relevant motion modes were identified according to their contributions to the specific function of proteins. Then the key residue interactions important for the functional motions of the protein were predicted as the interactions whose perturbation largely influences the fluctuation along the internal coordinate. Using our proposed methods, the maltose transporter (MalFGK2) from E. Coli was studied. The functional motions and the key residue interactions that are related to the channel-gating function of this protein were successfully identified. 相似文献
4.
5.
Genetic association mapping has been widely applied to determine genetic markers favorably associated with a trait of interest and provide information for marker-assisted selection. Many association mapping studies commonly focus on main effects due to intolerable computing intensity. This study aims to select several sets of DNA markers with potential epistasis to maximize genetic variations of some key agronomic traits in barley. By doing so, we integrated a MDR (multifactor dimensionality reduction) method with a forward variable selection approach. This integrated approach was used to determine single nucleotide polymorphism pairs with epistasis effects associated with three agronomic traits: heading date, plant height, and grain yield in barley from the barley Coordinated Agricultural Project. Our results showed that four, seven, and five SNP pairs accounted for 51.06, 45.66 and 40.42% for heading date, plant height, and grain yield, respectively with epistasis being considered, while corresponding contributions to these three traits were 45.32, 31.39, 31.31%, respectively without epistasis being included. The results suggested that epistasis model was more effective than non-epistasis model in this study and can be more preferred for other applications. 相似文献
6.
7.
<正>There is no experiencing without an experiencer,the self.Whether the experiencer knows it is"the self"that is experiencing is a different and tricky philosophical issue.Dating back to Ivan Pavlov’s dogs,the"experience"of animals has 相似文献
8.
9.
B cell activating factor (BAFF) is a member of the tumor necrosis factor family that is known to play an important role in B cell activation, proliferation, and differentiation in mammals. However, studies of BAFF in teleosts are very limited and its function, in particular that under in vivo conditions, is essentially unknown. In this study, we conducted in vivo as well as in vitro functional analyses of a BAFF homologue (CsBAFF) from the teleost fish tongue sole (Cynoglossus semilaevis). CsBAFF is composed of 261 residues and shares moderate sequence identities with known BAFFs of other teleosts. CsBAFF expression was most abundant in immune organs and was upregulated during bacterial infection. Purified recombinant CsBAFF (rCsBAFF) bound to tongue sole lymphocytes and promoted cellular proliferation and survival. The results of an in vivo study showed that CsBAFF overexpression in tongue sole significantly enhanced macrophage activation and reduced bacterial infection in fish tissues, whereas knockdown of CsBAFF expression resulted in increased bacterial dissemination and colonization in fish tissues. Furthermore, vaccination studies showed that CsBAFF enhanced the immunoprotection of a DNA vaccine and augmented the production of specific serum antibodies. Taken together, these results provide the first in vivo evidence to indicate that teleost BAFF is an immunostimulator that significantly contributes to the innate antibacterial immune response and vaccine-induced adaptive immune response. 相似文献
10.