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   3697026篇
  免费   322019篇
  国内免费   13730篇
耳鼻咽喉   50987篇
儿科学   118393篇
妇产科学   97466篇
基础医学   580572篇
口腔科学   103390篇
临床医学   332053篇
内科学   659969篇
皮肤病学   95397篇
神经病学   317052篇
特种医学   148900篇
外国民族医学   497篇
外科学   572942篇
综合类   113717篇
现状与发展   34篇
一般理论   2375篇
预防医学   307554篇
眼科学   85836篇
药学   259515篇
  19篇
中国医学   10129篇
肿瘤学   175978篇
  2021年   55122篇
  2020年   35342篇
  2019年   58063篇
  2018年   71749篇
  2017年   54459篇
  2016年   60327篇
  2015年   74271篇
  2014年   108635篇
  2013年   173825篇
  2012年   97356篇
  2011年   97771篇
  2010年   118097篇
  2009年   122592篇
  2008年   85519篇
  2007年   88789篇
  2006年   99738篇
  2005年   94828篇
  2004年   97391篇
  2003年   87849篇
  2002年   77686篇
  2001年   120936篇
  2000年   115187篇
  1999年   111800篇
  1998年   67191篇
  1997年   64722篇
  1996年   62724篇
  1995年   58300篇
  1994年   52419篇
  1993年   48958篇
  1992年   82983篇
  1991年   79434篇
  1990年   75990篇
  1989年   74662篇
  1988年   69480篇
  1987年   68175篇
  1986年   64964篇
  1985年   64830篇
  1984年   56605篇
  1983年   51310篇
  1982年   44783篇
  1981年   41937篇
  1980年   39536篇
  1979年   48971篇
  1978年   40971篇
  1977年   36793篇
  1976年   34083篇
  1975年   32845篇
  1974年   35536篇
  1973年   34201篇
  1972年   31694篇
排序方式: 共有10000条查询结果,搜索用时 187 毫秒
171.
172.
173.

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   
174.
175.
176.
177.
Metabolism describes the series of chemical reactions that are concerned with the provision of energy to biological systems. They may be divided into reactions involved in energy yield (catabolism: demand exceeds supply), and energy storage (anabolism: supply exceeds demand). Regulation of these pathways is critical for homeostasis, and derangements in metabolism are seen in a wide variety of pathological processes. Understanding metabolism is key to the treatment of many diseases, notably diabetes, as well as underpinning clinical nutritional support.  相似文献   
178.
179.

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   
180.
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