全文获取类型
收费全文 | 2656477篇 |
免费 | 187349篇 |
国内免费 | 3700篇 |
专业分类
耳鼻咽喉 | 36185篇 |
儿科学 | 86191篇 |
妇产科学 | 71001篇 |
基础医学 | 397442篇 |
口腔科学 | 71490篇 |
临床医学 | 239102篇 |
内科学 | 511615篇 |
皮肤病学 | 58923篇 |
神经病学 | 206351篇 |
特种医学 | 99468篇 |
外国民族医学 | 532篇 |
外科学 | 398478篇 |
综合类 | 52906篇 |
现状与发展 | 12篇 |
一般理论 | 921篇 |
预防医学 | 206509篇 |
眼科学 | 62364篇 |
药学 | 198377篇 |
11篇 | |
中国医学 | 5265篇 |
肿瘤学 | 144383篇 |
出版年
2021年 | 21210篇 |
2019年 | 21636篇 |
2018年 | 30148篇 |
2017年 | 22564篇 |
2016年 | 25356篇 |
2015年 | 28539篇 |
2014年 | 40104篇 |
2013年 | 60238篇 |
2012年 | 83739篇 |
2011年 | 89340篇 |
2010年 | 52850篇 |
2009年 | 49723篇 |
2008年 | 83607篇 |
2007年 | 89368篇 |
2006年 | 89945篇 |
2005年 | 86963篇 |
2004年 | 83381篇 |
2003年 | 80464篇 |
2002年 | 77774篇 |
2001年 | 120278篇 |
2000年 | 123226篇 |
1999年 | 103443篇 |
1998年 | 29941篇 |
1997年 | 26193篇 |
1996年 | 26535篇 |
1995年 | 25036篇 |
1994年 | 23019篇 |
1993年 | 21732篇 |
1992年 | 79668篇 |
1991年 | 78433篇 |
1990年 | 76731篇 |
1989年 | 73995篇 |
1988年 | 68004篇 |
1987年 | 66951篇 |
1986年 | 62521篇 |
1985年 | 60186篇 |
1984年 | 44739篇 |
1983年 | 38036篇 |
1982年 | 22341篇 |
1979年 | 41334篇 |
1978年 | 29617篇 |
1977年 | 24425篇 |
1976年 | 23697篇 |
1975年 | 25946篇 |
1974年 | 30740篇 |
1973年 | 29319篇 |
1972年 | 27472篇 |
1971年 | 26080篇 |
1970年 | 24017篇 |
1969年 | 22955篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
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
44.
Stelter K. Theodoraki M. N. Becker S. Tsekmistrenko V. Olzowy B. Ledderose G. 《European archives of oto-rhino-laryngology》2015,272(3):639-639
European Archives of Oto-Rhino-Laryngology - 相似文献
45.
Haya Mohammed BSc MChB M. Yousuf Salmasi MRCS Massimo Caputo PhD Gianni D. Angelini PhD Hunaid A. Vohra PhD 《Journal of cardiac surgery》2020,35(6):1209-1219
Background
Limited data exists demonstrating the efficacy of minimally invasive surgery (MIS) compared to median sternotomy (MS) for multiple valvular disease (MVD). This systematic review and meta-analysis aims to compare operative and peri-operative outcomes of MIS vs MS in MVD.Methods
PubMed, Ovid, and Embase were searched from inception until August 2019 for randomized and observational studies comparing MIS and MS in patients with MVD. Clinical outcomes of intra- and postoperative times, reoperation for bleeding and surgical site infection were evaluated.Results
Five observational studies comparing 340 MIS vs 414 MS patients were eligible for qualitative and quantitative review. The quality of evidence assessed using the Newcastle-Ottawa scale was good for all included studies. Meta-analysis demonstrated increased cardiopulmonary bypass time for MIS patients (weighted mean difference [WMD], 0.487; 95% confidence interval [CI], 0.365-0.608; P < .0001). Similarly, aortic cross-clamp time was longer in patients undergoing MIS (WMD, 0.632; 95% CI, 0.509-0.755; P < .0001). No differences were found in operative mortality, reoperation for bleeding, surgical site infection, or hospital stay.Conclusions
MIS for MVD have similar short-term outcomes compared to MS. This adds value to the use of minimally invasive methods for multivalvular surgery, despite conferring longer operative times. However, the paucity in literature and learning curve associated with MIS warrants further evidence, ideally randomized control trials, to support these findings.46.
47.
48.
49.
Elizabeth M. Broad Laura J. Newsome Dustin A. Dew 《The journal of spinal cord medicine》2020,43(3):388-397
Objective: Report measured resting energy expenditure (REE) in wheelchair rugby athletes and evaluate agreement between REE and the prediction models of Chun, Cunningham, Harris-Benedict, Mifflin, Nightingale and Gorgey, and Owen.Design: Cohort-based validation study.Setting. Paralympic team training camp.Participants: Fourteen internationally competitive athletes who play wheelchair rugby, 13 of whom had cervical spinal cord injuries (SCI).Outcome Measures: A portable metabolic analyzer was used to measure REE following an overnight fast and dual-energy X-ray absorptiometry (DXA) was used to assess lean body mass for the prediction equations.Results: REE in the current sample was 1735?±?257?kcal?×?day?1 ranging from 1324 to 2068?kcal?×?day?1. Bland–Altman analyses revealed negative mean bias but similar limits of agreement between measured REE and scores predicted by Chun, Cunningham, Mifflin, Nightingale and Gorgey, and Owen models in elite athletes who play wheelchair rugby.Conclusion: Prediction models regressed on persons with and without SCI under-predicted REE of competitive wheelchair rugby athletes. This outcome may be explained by the higher REE/fat-free mass (FFM) ratio of current athletes compared to less active samples. Findings from the current study will help practitioners to determine nutrient intake needs on training days of varied intensity. 相似文献
50.
Iclea Rocha Gama Euclides Marinho Trindade-Filho Suzana Lima Oliveira Nassib Bezerra Bueno Isabelle Tenório Melo Cyro Rego Cabral-Junior Elenita M. Barros Jaqueline A. Galvão Wanessa S. Pereira Raphaela C. Ferreira Bruna R. Domingos Terezinha da Rocha Ataide 《Metabolic brain disease》2015,30(1):93-98