首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   11150篇
  免费   2806篇
  国内免费   50篇
耳鼻咽喉   181篇
儿科学   248篇
妇产科学   273篇
基础医学   543篇
口腔科学   329篇
临床医学   3653篇
内科学   2199篇
皮肤病学   268篇
神经病学   1186篇
特种医学   269篇
外科学   1942篇
综合类   50篇
预防医学   1468篇
眼科学   430篇
药学   232篇
中国医学   1篇
肿瘤学   734篇
  2024年   86篇
  2023年   497篇
  2022年   117篇
  2021年   300篇
  2020年   413篇
  2019年   216篇
  2018年   727篇
  2017年   791篇
  2016年   713篇
  2015年   752篇
  2014年   866篇
  2013年   904篇
  2012年   442篇
  2011年   478篇
  2010年   602篇
  2009年   715篇
  2008年   369篇
  2007年   318篇
  2006年   327篇
  2005年   305篇
  2004年   220篇
  2003年   212篇
  2002年   205篇
  2001年   252篇
  2000年   132篇
  1999年   247篇
  1998年   274篇
  1997年   258篇
  1996年   317篇
  1995年   220篇
  1994年   219篇
  1993年   179篇
  1992年   169篇
  1991年   154篇
  1990年   104篇
  1989年   113篇
  1988年   114篇
  1987年   100篇
  1986年   81篇
  1985年   74篇
  1984年   64篇
  1983年   63篇
  1982年   47篇
  1981年   25篇
  1980年   29篇
  1979年   25篇
  1978年   30篇
  1974年   16篇
  1971年   16篇
  1970年   16篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.

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.
  相似文献   
3.
4.
5.
Inbred mouse strains are the most widely used mammalian model organism in biomedical research owing to ease of genetic manipulation and short lifespan; however, each inbred strain possesses a unique repertoire of deleterious homozygous alleles that can make a specific strain more susceptible to a particular disease. In the current study, we report dystrophic cardiac calcinosis (DCC) in C.B‐17 SCID male mice at 10 weeks of age with no significant change in cardiac function. Acquisition of DCC was characterized by myocardial injury, fibrosis, calcification, and necrosis of the tissue. At 10 weeks of age, 38% of the C.B‐17 SCID mice from two different commercial colonies exhibited significant calcinosis on the ventricular epicardium, predominantly on the right ventricle. The frequency of calcinosis was more than 50% for mice obtained from Taconic's Cambridge City colony and 25% for mice obtained from Taconic's German Town colony. Interestingly, the DCC phenotype did not affect cardiac function at 10 weeks of age. No differences in echocardiography or electrocardiography were observed between the calcinotic and non‐calcinotic mice from either colony. Our findings suggest that C.B‐17 SCID mice exhibit DCC as early as 10 weeks of age with no significant impact on cardiac function. This strain of mice should be cautiously considered for the study of cardiac physiology.  相似文献   
6.
7.
8.
9.
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号