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   153043篇
  免费   10435篇
  国内免费   770篇
耳鼻咽喉   1406篇
儿科学   3901篇
妇产科学   2770篇
基础医学   20613篇
口腔科学   3456篇
临床医学   14750篇
内科学   33008篇
皮肤病学   2878篇
神经病学   14809篇
特种医学   6129篇
外国民族医学   6篇
外科学   23005篇
综合类   1907篇
现状与发展   2篇
一般理论   139篇
预防医学   11082篇
眼科学   3291篇
药学   10489篇
  2篇
中国医学   245篇
肿瘤学   10360篇
  2023年   818篇
  2022年   1238篇
  2021年   2829篇
  2020年   1956篇
  2019年   2816篇
  2018年   3427篇
  2017年   2664篇
  2016年   3045篇
  2015年   3512篇
  2014年   5032篇
  2013年   6801篇
  2012年   10520篇
  2011年   11139篇
  2010年   6351篇
  2009年   6043篇
  2008年   10197篇
  2007年   10879篇
  2006年   10348篇
  2005年   10599篇
  2004年   10006篇
  2003年   9492篇
  2002年   8914篇
  2001年   1493篇
  2000年   1118篇
  1999年   1600篇
  1998年   2111篇
  1997年   1647篇
  1996年   1431篇
  1995年   1292篇
  1994年   1141篇
  1993年   1116篇
  1992年   783篇
  1991年   797篇
  1990年   622篇
  1989年   605篇
  1988年   573篇
  1987年   580篇
  1986年   522篇
  1985年   549篇
  1984年   648篇
  1983年   572篇
  1982年   766篇
  1981年   708篇
  1980年   609篇
  1979年   369篇
  1978年   380篇
  1977年   409篇
  1976年   348篇
  1975年   296篇
  1974年   259篇
排序方式: 共有10000条查询结果,搜索用时 16 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