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   3490047篇
  免费   281742篇
  国内免费   14594篇
耳鼻咽喉   48466篇
儿科学   106960篇
妇产科学   91309篇
基础医学   547099篇
口腔科学   96895篇
临床医学   308484篇
内科学   618366篇
皮肤病学   93049篇
神经病学   298008篇
特种医学   138963篇
外国民族医学   453篇
外科学   543454篇
综合类   107094篇
现状与发展   24篇
一般理论   2263篇
预防医学   284383篇
眼科学   79632篇
药学   243042篇
  23篇
中国医学   10347篇
肿瘤学   168069篇
  2021年   54922篇
  2020年   35049篇
  2019年   58033篇
  2018年   70846篇
  2017年   54097篇
  2016年   59858篇
  2015年   73993篇
  2014年   108184篇
  2013年   173369篇
  2012年   90178篇
  2011年   89227篇
  2010年   115534篇
  2009年   120734篇
  2008年   77162篇
  2007年   80702篇
  2006年   91514篇
  2005年   86847篇
  2004年   89080篇
  2003年   80447篇
  2002年   70753篇
  2001年   109283篇
  2000年   102399篇
  1999年   101329篇
  1998年   65235篇
  1997年   63133篇
  1996年   60650篇
  1995年   56095篇
  1994年   50326篇
  1993年   47021篇
  1992年   71729篇
  1991年   68030篇
  1990年   65005篇
  1989年   64342篇
  1988年   60223篇
  1987年   58849篇
  1986年   56337篇
  1985年   55965篇
  1984年   50483篇
  1983年   45772篇
  1982年   42319篇
  1981年   39788篇
  1980年   37629篇
  1979年   42938篇
  1978年   37356篇
  1977年   34270篇
  1976年   31033篇
  1975年   30688篇
  1974年   32403篇
  1973年   31077篇
  1972年   29508篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
142.
143.
144.
145.
146.

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   
147.
148.
149.
150.
The aim of this study is to review the literature to find out the exact etiology of anastomotic cancers of colon post resection and differentiate them between a recurrence, second primary, and metastatic disease (local manifestation of systemic disease). Web-based literature search was done, and datas collected. We searched PubMed for papers using the keywords colon cancer recurrence, anastomotic recurrence, and recurrent colon carcinoma. We also searched for systematic review in the same topic. In addition, we used our personal referrence archive. Anastomotic recurrences of colon are postulated to arise due to inadequate margins, tumor implantation by exfoliated cells, altered biological properties of bowel anastomosis, and missed synchronous lesions. Some tumors are unique with repeated recurrence after repeated resection. Duration after primary surgery plays a major role in differentiating recurrent and second primary lesions. Repeated recurrences after repeated resections have to be considered a manifestation of systemic disease or metastatic disease due to the virulence of the disease. A detailed analysis and study of patients with colonic anastomotic lesion are required to differentiate it between a recurrent, a second primary lesion, and a metastatic disease (local manifestation of a systemic disease). The nomenclature is significant to study the survival of these patients, as a second primary lesion will have different survival compared to that of recurrent lesions.  相似文献   
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