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   2387768篇
  免费   186397篇
  国内免费   4590篇
耳鼻咽喉   31749篇
儿科学   78842篇
妇产科学   68017篇
基础医学   348046篇
口腔科学   66105篇
临床医学   220286篇
内科学   468735篇
皮肤病学   53609篇
神经病学   194938篇
特种医学   89740篇
外国民族医学   702篇
外科学   347581篇
综合类   53632篇
现状与发展   4篇
一般理论   972篇
预防医学   193849篇
眼科学   54465篇
药学   171658篇
  7篇
中国医学   4906篇
肿瘤学   130912篇
  2019年   19194篇
  2018年   26493篇
  2017年   20246篇
  2016年   22587篇
  2015年   25523篇
  2014年   35940篇
  2013年   54280篇
  2012年   73584篇
  2011年   78474篇
  2010年   45947篇
  2009年   44001篇
  2008年   73184篇
  2007年   77975篇
  2006年   77998篇
  2005年   75938篇
  2004年   72911篇
  2003年   69637篇
  2002年   67433篇
  2001年   111879篇
  2000年   114227篇
  1999年   95379篇
  1998年   27152篇
  1997年   24637篇
  1996年   24964篇
  1995年   23685篇
  1994年   21770篇
  1993年   20362篇
  1992年   73838篇
  1991年   71699篇
  1990年   69065篇
  1989年   66519篇
  1988年   61325篇
  1987年   59964篇
  1986年   56561篇
  1985年   53747篇
  1984年   41008篇
  1983年   35276篇
  1982年   21190篇
  1981年   19183篇
  1979年   37631篇
  1978年   27188篇
  1977年   22653篇
  1976年   21211篇
  1975年   22320篇
  1974年   27119篇
  1973年   26455篇
  1972年   24942篇
  1971年   22981篇
  1970年   21719篇
  1969年   20359篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
52.

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   
53.
54.
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   
55.

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   
56.
57.
58.
59.
60.
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