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   1303855篇
  免费   100158篇
  国内免费   1961篇
耳鼻咽喉   17062篇
儿科学   41822篇
妇产科学   35721篇
基础医学   196193篇
口腔科学   35413篇
临床医学   121685篇
内科学   255566篇
皮肤病学   28814篇
神经病学   105558篇
特种医学   49346篇
外国民族医学   265篇
外科学   183501篇
综合类   26137篇
现状与发展   4篇
一般理论   581篇
预防医学   107064篇
眼科学   29214篇
药学   96399篇
  6篇
中国医学   2438篇
肿瘤学   73185篇
  2021年   10657篇
  2019年   11072篇
  2018年   14725篇
  2017年   11326篇
  2016年   12738篇
  2015年   14900篇
  2014年   20172篇
  2013年   30003篇
  2012年   41145篇
  2011年   43466篇
  2010年   25202篇
  2009年   24017篇
  2008年   40193篇
  2007年   42794篇
  2006年   42118篇
  2005年   41127篇
  2004年   39274篇
  2003年   37483篇
  2002年   36267篇
  2001年   56786篇
  2000年   57750篇
  1999年   48723篇
  1998年   13709篇
  1997年   12505篇
  1996年   12885篇
  1995年   12142篇
  1994年   11296篇
  1992年   38625篇
  1991年   38132篇
  1990年   36832篇
  1989年   35676篇
  1988年   33095篇
  1987年   32461篇
  1986年   30893篇
  1985年   29121篇
  1984年   22193篇
  1983年   19370篇
  1982年   11491篇
  1979年   21106篇
  1978年   15553篇
  1977年   12855篇
  1976年   11907篇
  1975年   12888篇
  1974年   15709篇
  1973年   15499篇
  1972年   14642篇
  1971年   13630篇
  1970年   12858篇
  1969年   12150篇
  1968年   11303篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
31.

Objective

Comparative survival between neoadjuvant chemotherapy and adjuvant chemotherapy for patients with cT2-4N0-1M0 non–small cell lung cancer has not been extensively studied.

Methods

Patients with cT2-4N0-1M0 non–small cell lung cancer who received platinum-based chemotherapy were retrospectively identified. Exclusion criteria included stage IV disease, induction radiotherapy, and targeted therapy. The primary end point was disease-free survival. Secondary end points were overall survival, chemotherapy tolerance, and ability of Response Evaluation Criteria In Solid Tumors response to predict survival. Survival was estimated using the Kaplan–Meier method, compared using the log-rank test and Cox proportional hazards models, and stratified using matched pairs after propensity score matching.

Results

In total, 330 patients met the inclusion criteria (n = 92/group after propensity-score matching; median follow-up, 42 months). Five-year disease-free survival was 49% (95% confidence interval, 39-61) for neoadjuvant chemotherapy versus 48% (95% confidence interval, 38-61) for adjuvant chemotherapy (P = .70). On multivariable analysis, disease-free survival was not associated with neoadjuvant chemotherapy or adjuvant chemotherapy (hazard ratio, 1.1; 95% confidence interval, 0.64-1.90; P = .737), nor was overall survival (hazard ratio, 1.21; 95% confidence interval, 0.63-2.30; P = .572). The neoadjuvant chemotherapy group was more likely to receive full doses and cycles of chemotherapy (P = .014/0.005) and had fewer grade 3 or greater toxicities (P = .001). Response Evaluation Criteria In Solid Tumors response to neoadjuvant chemotherapy was associated with disease-free survival (P = .035); 15% of patients receiving neoadjuvant chemotherapy (14/92) had a major pathologic response.

Conclusions

Timing of chemotherapy, before or after surgery, is not associated with an improvement in overall or disease-free survival among patients with cT2-4N0-1M0 non–small cell lung cancer who undergo complete surgical resection.  相似文献   
32.
33.

Introduction

Several studies demonstrated that simulator-acquired skill transfer to the operating room is incomplete. Our objective was to identify trainee characteristics that predict the transfer of simulator-acquired skill to the operating room.

Methods

Trainees completed baseline assessments including intracorporeal suturing (IS) performance, attentional selectivity, self-reported use of mental skills, and self-reported prior clinical and simulated laparoscopic experience and confidence. Residents then followed proficiency-based laparoscopic skills training, and their skill transfer was assessed on a live-anesthetized porcine model. Predictive characteristics for transfer test performance were assessed using multiple linear regression.

Results

Thirty-eight residents completed the study. Automaticity, attentional selectivity, resident perceived ability with laparoscopy and simulators, and post-training IS performance were predictive of IS performance during the transfer test.

Conclusions

Promoting automaticity, self-efficacy, and attention selectivity may help improve the transfer of simulator-acquired skill. Mental skills training and training to automaticity may therefore be valuable interventions to achieve this goal.  相似文献   
34.
35.
36.
37.
38.
Direct peroral cholangioscopy (POC) using an ultra‐slim upper endoscope is one modality of POC for intraductal endoscopic evaluation and treatment of the bile duct. Choledochoduodenostomy (CDS) is one modality of biliary bypass surgery that provides a new route to the bile duct. We carried out direct POC using an ultra‐slim upper endoscope without the use of accessories in 10 patients (four sump syndromes, three bile duct strictures and three intrahepatic duct stones) previously undergoing surgical CDS. Direct POC was successful in all patients. The use of an intraductal balloon catheter was required in one patient for advancement of the endoscope into the bile duct. Distal bile ducts with sump syndromes were cleared using baskets and water irrigation under direct POC. Cholangiocarcinoma was diagnosed in one patient with hilar bile duct stricture after cholangioscopic evaluation and a targeting forceps biopsy under direct POC. Intrahepatic duct stones were successfully extracted after intraductal fragmentation under direct POC. Oozing bleeding occurred during intraductal lithotripsy but stopped spontaneously. Direct POC using an ultra‐slim upper endoscope without the assistance of accessories can easily be carried out in patients undergoing CDS.  相似文献   
39.
40.
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