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   1317篇
  免费   86篇
  国内免费   5篇
耳鼻咽喉   2篇
儿科学   104篇
妇产科学   19篇
基础医学   133篇
口腔科学   57篇
临床医学   95篇
内科学   259篇
皮肤病学   15篇
神经病学   25篇
特种医学   97篇
外科学   227篇
综合类   150篇
预防医学   51篇
眼科学   50篇
药学   69篇
肿瘤学   55篇
  2022年   17篇
  2021年   54篇
  2020年   11篇
  2019年   32篇
  2018年   41篇
  2017年   25篇
  2016年   20篇
  2015年   28篇
  2014年   27篇
  2013年   28篇
  2012年   40篇
  2011年   64篇
  2010年   43篇
  2009年   46篇
  2008年   67篇
  2007年   62篇
  2006年   73篇
  2005年   43篇
  2004年   43篇
  2003年   38篇
  2002年   41篇
  2001年   25篇
  2000年   26篇
  1999年   27篇
  1998年   36篇
  1997年   29篇
  1996年   37篇
  1995年   21篇
  1994年   35篇
  1993年   13篇
  1992年   24篇
  1991年   17篇
  1990年   19篇
  1989年   22篇
  1988年   20篇
  1987年   19篇
  1986年   17篇
  1985年   19篇
  1984年   13篇
  1983年   13篇
  1982年   10篇
  1981年   16篇
  1980年   10篇
  1979年   14篇
  1978年   8篇
  1976年   7篇
  1975年   12篇
  1974年   9篇
  1973年   11篇
  1972年   7篇
排序方式: 共有1408条查询结果,搜索用时 15 毫秒
1.

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   
2.
3.
4.
5.
In order to evaluate the effects of pentoxifylline on sperm motility and longevity, a controlled in-vitro study was conducted on normozoospermic donor semen samples using the Cellsoft automated system for sperm motility analysis. After incubation and selection, pentoxifylline was found to improve the recovery of spermatozoa and to increase their velocity. In the subgroup of progressively motile spermatozoa, curvilinear velocity was also enhanced. It is concluded that pentoxifylline has an effect on the vigour, but not on the pattern, of sperm motion. Pentoxifylline did not improve the motility characteristics of senescent spermatozoa in normozoospermic sperm samples. Sperm survival, as shown by supra-vital staining, and motility longevity both decreased with time after pentoxifylline treatment.  相似文献   
6.
7.
A study of 17 patients with autoimmune axonal or demyelinating peripheral neuropathy in combination with M-component is described. The M-component was associated with MGUS (monoclonal gammopathy of undetermined significance) in 12 patients, CLL in one patient, WaldenstrÖm's disease in one patient, and myeloma in three patients. Immunohistological examination with direct and indirect fluorescence showed binding of antibodies to nerve structures of the same class and light chain as seen in the M-component. In five cases of IgM M-component, the demyelinating neuropathy was caused by binding of the IgM M-protein and complement C3b to myelin-associated glycoproteins (MAG). In 12 cases with axonal neuropathy, binding of IgG to the connective tissue of the peri- and endoneurium was found in 50% of cases, IgM in five cases, and IgD in one case. None of the patients had central nervous system (CNS) symptoms. The clinical and therapeutic difficulties are discussed; only two patients with an acute course responded to immunosuppression. A marked co-expression of other autoimmune phenomena is interpreted in the light of cross-reactions between the autoantibody and similar tissue autoantigens.  相似文献   
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