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   1751篇
  免费   294篇
  国内免费   39篇
耳鼻咽喉   17篇
儿科学   102篇
妇产科学   19篇
基础医学   101篇
口腔科学   34篇
临床医学   293篇
内科学   589篇
皮肤病学   60篇
神经病学   176篇
特种医学   279篇
外科学   188篇
综合类   31篇
预防医学   66篇
眼科学   16篇
药学   57篇
中国医学   1篇
肿瘤学   55篇
  2024年   9篇
  2023年   52篇
  2022年   13篇
  2021年   29篇
  2020年   90篇
  2019年   14篇
  2018年   89篇
  2017年   69篇
  2016年   68篇
  2015年   62篇
  2014年   94篇
  2013年   110篇
  2012年   45篇
  2011年   36篇
  2010年   80篇
  2009年   109篇
  2008年   42篇
  2007年   46篇
  2006年   43篇
  2005年   28篇
  2004年   15篇
  2003年   17篇
  2002年   15篇
  2001年   32篇
  2000年   14篇
  1999年   25篇
  1998年   80篇
  1997年   96篇
  1996年   78篇
  1995年   68篇
  1994年   50篇
  1993年   52篇
  1992年   31篇
  1991年   16篇
  1990年   25篇
  1989年   54篇
  1988年   43篇
  1987年   27篇
  1986年   22篇
  1985年   23篇
  1984年   18篇
  1983年   11篇
  1982年   14篇
  1981年   15篇
  1980年   15篇
  1979年   9篇
  1977年   9篇
  1976年   11篇
  1975年   8篇
  1971年   8篇
排序方式: 共有2084条查询结果,搜索用时 15 毫秒
81.
82.
Rupture of sinus of valsalva following repair of tetralogy of fallot (TOF) is very rare. It should be suspected as a cause of recurrent or prolonged pleural effusion and congestive cardiac failure in patients who have undergone repair of TOF. We report one such patient.  相似文献   
83.
We present images from computed tomography angiography in a 40-year-old female with a calcified pseudo-aneurysm in her left coronary artery, who had previously undergone repair of tetralogy of Fallot.  相似文献   
84.
We present a case of type B aortic dissection with a rare aortic arch branching variation whereby two separate brachiocephalic trunks arise from the arch. This case also highlights the potential implications of this variant in the management of thoracic aortic dissections and aneurysms.  相似文献   
85.
86.

Introduction

In 2009 the Department of Health instructed McKinsey & Company to provide advice on how commissioners might achieve world class National Health Service productivity. Asymptomatic inguinal hernia repair was identified as a potentially cosmetic procedure, with limited clinical benefit. The Birmingham and Solihull primary care trust cluster introduced a policy of watchful waiting for asymptomatic inguinal hernia, which was implemented across the health economy in December 2010. This retrospective cohort study aimed to examine the effect of a change in clinical commissioning policy concerning elective surgical repair of asymptomatic inguinal hernias.

Methods

A total of 1,032 patients undergoing inguinal hernia repair in the 16 months after the policy change were compared with 978 patients in the 16 months before. The main outcome measure was relative proportion of emergency repair in groups before and after the policy change. Multivariate binary logistic regression was used to adjust the main outcome for age, sex and hernia type.

Results

The period after the policy change was associated with 59% higher odds of emergency repair (3.6% vs 5.5%, adjusted odds ratio [OR]: 1.59, 95% confidence interval [CI]: 1.03–2.47). In turn, emergency repair was associated with higher odds of adverse events (4.7% vs 18.5%, adjusted OR: 3.68, 95% CI: 2.04–6.63) and mortality (0.1% vs 5.4%, p<0.001, Fisher’s exact test).

Conclusions

Introduction of a watchful waiting policy for asymptomatic inguinal hernias was associated with a significant increase in need for emergency repair, which was in turn associated with an increased risk of adverse events. Current policies may be placing patients at risk.  相似文献   
87.
88.
89.
90.
The precise mechanisms regulating T-helper function have been intensively investigated. We and others have recently identified a new T-cell-B-cell-activating molecule called T-BAM that directs B-cell differentiation by interacting with the CD40 molecule on B cells. Using a specific monoclonal antibody against T-BAM (5C8), we have previously shown that T-BAM expressing T cells are predominantly CD4+CD8- and in normal lymphoid tissue have a unique distribution. However, no information has been obtained regarding the phenotype and functional properties of human neoplastic T cells. Therefore, we investigated T- BAM expression immunohistochemically in 87 well-characterized T-cell non-Hodgkin's lymphomas and lymphoid leukemias (LL). We found that 21/81 neoplasms expressed detectable T-BAM and these positive tumors belong almost exclusively to the CD4+CD8- subtype. In addition, to determine whether T-BAM expression could be induced on T-BAM-LL cells, we activated T-BAM-LLs in vitro and showed that T-BAM could be upregulated only in CD4+CD8- tumors. Our studies clearly show that T- BAM is constitutively expressed in a large number of T-cell neoplasms with a relative mature phenotype (CD4+CD8-) and that only CD4+ neoplastic T cells can be induced in vitro to express this molecule. Additional studies are necessary to identify the biologic significance of T-BAM expression and its potential and clinical implications.  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