全文获取类型
收费全文 | 2350189篇 |
免费 | 171270篇 |
国内免费 | 3331篇 |
专业分类
耳鼻咽喉 | 32050篇 |
儿科学 | 75891篇 |
妇产科学 | 62685篇 |
基础医学 | 348188篇 |
口腔科学 | 63634篇 |
临床医学 | 211356篇 |
内科学 | 457274篇 |
皮肤病学 | 51730篇 |
神经病学 | 185288篇 |
特种医学 | 88012篇 |
外国民族医学 | 489篇 |
外科学 | 353862篇 |
综合类 | 47509篇 |
现状与发展 | 12篇 |
一般理论 | 848篇 |
预防医学 | 182732篇 |
眼科学 | 54325篇 |
药学 | 175109篇 |
11篇 | |
中国医学 | 4575篇 |
肿瘤学 | 129210篇 |
出版年
2021年 | 18984篇 |
2019年 | 19537篇 |
2018年 | 27058篇 |
2017年 | 20360篇 |
2016年 | 22745篇 |
2015年 | 25638篇 |
2014年 | 36094篇 |
2013年 | 53953篇 |
2012年 | 74676篇 |
2011年 | 79411篇 |
2010年 | 47056篇 |
2009年 | 44565篇 |
2008年 | 74610篇 |
2007年 | 79478篇 |
2006年 | 80298篇 |
2005年 | 77782篇 |
2004年 | 74370篇 |
2003年 | 71694篇 |
2002年 | 69363篇 |
2001年 | 108739篇 |
2000年 | 111452篇 |
1999年 | 93494篇 |
1998年 | 26990篇 |
1997年 | 23658篇 |
1996年 | 24056篇 |
1995年 | 22716篇 |
1994年 | 20894篇 |
1993年 | 19712篇 |
1992年 | 72000篇 |
1991年 | 70070篇 |
1990年 | 68392篇 |
1989年 | 65664篇 |
1988年 | 60305篇 |
1987年 | 59125篇 |
1986年 | 55217篇 |
1985年 | 53004篇 |
1984年 | 39312篇 |
1983年 | 33397篇 |
1982年 | 19858篇 |
1979年 | 35867篇 |
1978年 | 25652篇 |
1977年 | 21230篇 |
1976年 | 20333篇 |
1975年 | 21816篇 |
1974年 | 26150篇 |
1973年 | 24805篇 |
1972年 | 23201篇 |
1971年 | 22040篇 |
1970年 | 20250篇 |
1969年 | 19318篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
32.
33.
34.
35.
36.
37.
E. Likotrafiti K. M. Tuohy G. R. Gibson R. A. Rastall 《International journal of food sciences and nutrition》2016,67(2):83-91
The aim of the present study was to evaluate the antimicrobial activity of two synbiotic combinations, Lactobacillus fermentum with short-chain fructooligosaccharides (FOS-LF) and Bifidobacterium longum with isomaltooligosaccharides (IMO-BL), against enterohaemorrhagic Escherichia coli O157:H7 and enteropathogenic E. coli O86. Antimicrobial activity was determined (1) by co-culturing the synbiotics and pathogens in batch cultures, and (2) with the three-stage continuous culture system (gut model), inoculated with faecal slurry from an elderly donor. In the co-culture experiments, IMO-BL was significantly inhibitory to both E. coli strains, while FOS-LF was slightly inhibitory or not inhibitory. Factors other than acid production appeared to play a role in the inhibition. In the gut models, both synbiotics effectively inhibited E. coli O157 in the first vessel, but not in vessels 2 and 3. E. coli O86 was not significantly inhibited. 相似文献
38.
39.
40.
N. S. Hari Narayana Moorthy Sergio F. Sousa Maria J. Ramos Pedro A. Fernandes 《Medicinal chemistry research》2016,25(7):1340-1357
Farnesyltransferase (FTase) is one of the prenyltransferase family enzymes that catalyse the transfer of 15-membered isoprenoid (farnesyl) moiety to the cysteine of CAAX motif-containing proteins including Rho and Ras family of G proteins. Inhibitors of FTase act as drugs for cancer, malaria, progeria and other diseases. In the present investigation, we have developed two structure-based pharmacophore models from protein–ligand complex (3E33 and 3E37) obtained from the protein data bank. Molecular dynamics (MD) simulations were performed on the complexes, and different conformers of the same complex were generated. These conformers were undergone protein–ligand interaction fingerprint (PLIF) analysis, and the fingerprint bits have been used for structure-based pharmacophore model development. The PLIF results showed that Lys164, Tyr166, TrpB106 and TyrB361 are the major interacting residues in both the complexes. The RMSD and RMSF analyses on the MD-simulated systems showed that the absence of FPP in the complex 3E37 has significant effect in the conformational changes of the ligands. During this conformational change, some interactions between the protein and the ligands are lost, but regained after some simulations (after 2 ns). The structure-based pharmacophore models showed that the hydrophobic and acceptor contours are predominantly present in the models. The pharmacophore models were validated using reference compounds, which significantly identified as HITs with smaller RMSD values. The developed structure-based pharmacophore models are significant, and the methodology used in this study is novel from the existing methods (the original X-ray crystallographic coordination of the ligands is used for the model building). In our study, along with the original coordination of the ligand, different conformers of the same complex (protein–ligand) are used. It concluded that the developed methodology is significant for the virtual screening of novel molecules on different targets. 相似文献