全文获取类型
收费全文 | 2587944篇 |
免费 | 184508篇 |
国内免费 | 7568篇 |
专业分类
耳鼻咽喉 | 34272篇 |
儿科学 | 85201篇 |
妇产科学 | 71577篇 |
基础医学 | 363581篇 |
口腔科学 | 69658篇 |
临床医学 | 234492篇 |
内科学 | 515495篇 |
皮肤病学 | 62450篇 |
神经病学 | 213462篇 |
特种医学 | 99883篇 |
外国民族医学 | 736篇 |
外科学 | 386411篇 |
综合类 | 50392篇 |
现状与发展 | 5篇 |
一般理论 | 968篇 |
预防医学 | 196191篇 |
眼科学 | 56691篇 |
药学 | 187988篇 |
8篇 | |
中国医学 | 5331篇 |
肿瘤学 | 145228篇 |
出版年
2021年 | 19982篇 |
2019年 | 20621篇 |
2018年 | 29285篇 |
2017年 | 22592篇 |
2016年 | 26225篇 |
2015年 | 29501篇 |
2014年 | 40438篇 |
2013年 | 60421篇 |
2012年 | 80219篇 |
2011年 | 84482篇 |
2010年 | 51002篇 |
2009年 | 49152篇 |
2008年 | 79016篇 |
2007年 | 83831篇 |
2006年 | 85567篇 |
2005年 | 81730篇 |
2004年 | 78725篇 |
2003年 | 76041篇 |
2002年 | 73330篇 |
2001年 | 128408篇 |
2000年 | 131332篇 |
1999年 | 110503篇 |
1998年 | 31255篇 |
1997年 | 27921篇 |
1996年 | 28218篇 |
1995年 | 27385篇 |
1994年 | 25069篇 |
1993年 | 23421篇 |
1992年 | 85164篇 |
1991年 | 81566篇 |
1990年 | 78786篇 |
1989年 | 76060篇 |
1988年 | 69469篇 |
1987年 | 67998篇 |
1986年 | 63545篇 |
1985年 | 60512篇 |
1984年 | 44941篇 |
1983年 | 37945篇 |
1982年 | 22456篇 |
1981年 | 19984篇 |
1979年 | 38959篇 |
1978年 | 27439篇 |
1977年 | 23252篇 |
1976年 | 21495篇 |
1975年 | 22813篇 |
1974年 | 26786篇 |
1973年 | 25370篇 |
1972年 | 23749篇 |
1971年 | 21956篇 |
1970年 | 20184篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
53.
54.
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
55.
56.
57.
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
58.
59.
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.60.