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   153791篇
  免费   10461篇
  国内免费   770篇
耳鼻咽喉   1412篇
儿科学   3934篇
妇产科学   2840篇
基础医学   20720篇
口腔科学   3455篇
临床医学   14826篇
内科学   33103篇
皮肤病学   2891篇
神经病学   14926篇
特种医学   6162篇
外国民族医学   6篇
外科学   23154篇
综合类   1911篇
现状与发展   2篇
一般理论   141篇
预防医学   11068篇
眼科学   3259篇
药学   10601篇
  2篇
中国医学   245篇
肿瘤学   10364篇
  2023年   821篇
  2022年   1242篇
  2021年   2839篇
  2020年   1961篇
  2019年   2828篇
  2018年   3437篇
  2017年   2672篇
  2016年   3056篇
  2015年   3533篇
  2014年   5056篇
  2013年   6836篇
  2012年   10556篇
  2011年   11201篇
  2010年   6373篇
  2009年   6072篇
  2008年   10243篇
  2007年   10912篇
  2006年   10400篇
  2005年   10642篇
  2004年   10049篇
  2003年   9530篇
  2002年   8944篇
  2001年   1520篇
  2000年   1151篇
  1999年   1614篇
  1998年   2120篇
  1997年   1649篇
  1996年   1430篇
  1995年   1297篇
  1994年   1150篇
  1993年   1121篇
  1992年   788篇
  1991年   798篇
  1990年   627篇
  1989年   612篇
  1988年   565篇
  1987年   586篇
  1986年   516篇
  1985年   551篇
  1984年   652篇
  1983年   580篇
  1982年   767篇
  1981年   706篇
  1980年   606篇
  1979年   380篇
  1978年   378篇
  1977年   406篇
  1976年   345篇
  1975年   298篇
  1974年   254篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
The identification of EGFR mutations in non‐small‐cell lung cancer is important for selecting patients, who may benefit from treatment with EGFR tyrosine kinase inhibitors. The analysis is usually performed on cytological aspirates and/or histological needle biopsies, representing a small fraction of the tumour volume. The aim of the present investigation was to evaluate the diagnostic performance of this molecular test. We retrospectively included 201 patients with primary adenocarcinoma of the lung. EGFR mutation status (exon 19 deletions and exon 21 L858R point mutation) was evaluated on both pre‐operative biopsies (131 histological and 70 cytological) and on the surgical specimens, using PCR. Samples with low tumour cell fraction were assigned to laser micro‐dissection (LMD). We found nine (4.5%) patients with EGFR mutation in the lung tumour resections, but failed to identify mutation in one of the corresponding pre‐operative, cytological specimens. Several (18.4%) analyses of the pre‐operative biopsies were inconclusive, especially in case of biopsies undergoing LMD and regarding exon 21 analysis. Discrepancy of mutation status in one patient may reflect intra‐tumoural heterogeneity or technical issues. Moreover, several inconclusive results in the diagnostic biopsies reveal that attention must be paid on the suitability of pre‐operative biopsies for EGFR mutation analysis.  相似文献   
23.
24.
25.
26.
27.
Arthroscopic acromioclavicular joint excision is a commonly performed but technically demanding procedure. Incomplete excision can leave residual symptoms. We present a simple, reproducible technique ensuring satisfactory excision of the joint.  相似文献   
28.
29.

Objective

Arch obstruction after the Norwood procedure is common and contributes to mortality. We determined the prevalence, associated factors, and practice variability of arch reintervention and assessed whether arch reintervention is associated with mortality.

Methods

From 2005 to 2017, 593 neonates in the Congenital Heart Surgeons' Society Critical Left Heart Obstruction cohort underwent a Norwood procedure. Median follow-up was 3.7 years. Multivariable parametric models, including a modulated renewal analysis, were performed.

Results

Of the 593 neonates, 146 (25%) underwent 218 reinterventions for arch obstruction after the Norwood procedure: catheter-based (n = 168) or surgical (n = 50) at a median age of 4.3 months (quartile 1-quartile 3, 2.6-5.7). Interdigitation of the distal aortic anastomosis was protective against arch reintervention. Development of ≥ moderate tricuspid valve regurgitation and right ventricular dysfunction at any point was associated with arch reintervention. Nonsignificant variables for arch reintervention included shunt type and preoperative aortic measurements. Surgical arch reintervention was protective against arch reintervention, but transcatheter reintervention was associated with increased reintervention. Arch reintervention was not associated with increased mortality. There was wide institutional variation in incidence of arch reintervention (range, 0-40 reinterventions per 100 years patient follow-up) and in preintervention gradient (range, 0-64 mm Hg).

Conclusions

Interdigitation of the distal aortic anastomosis during the Norwood procedure decreased the risk of arch reintervention. Surgical arch reintervention is more definitive than transcatheter. Arch reintervention after the Norwood procedure is not associated with increased mortality. Serial surveillance for arch obstruction, integrated with changes in right ventricular function and tricuspid valve regurgitation, is recommended after the Norwood procedure to improve outcomes.  相似文献   
30.
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