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   4786594篇
  免费   377064篇
  国内免费   14342篇
耳鼻咽喉   67325篇
儿科学   154638篇
妇产科学   128062篇
基础医学   725290篇
口腔科学   132795篇
临床医学   440201篇
内科学   868806篇
皮肤病学   116793篇
神经病学   394595篇
特种医学   185652篇
外国民族医学   738篇
外科学   724996篇
综合类   134200篇
现状与发展   24篇
一般理论   2821篇
预防医学   403150篇
眼科学   113610篇
药学   337637篇
  27篇
中国医学   12237篇
肿瘤学   234403篇
  2021年   56192篇
  2019年   58750篇
  2018年   75084篇
  2017年   57158篇
  2016年   63322篇
  2015年   75898篇
  2014年   110371篇
  2013年   175590篇
  2012年   137540篇
  2011年   146091篇
  2010年   130006篇
  2009年   129869篇
  2008年   132150篇
  2007年   141975篇
  2006年   149255篇
  2005年   144459篇
  2004年   144226篇
  2003年   134134篇
  2002年   123391篇
  2001年   176952篇
  2000年   172872篇
  1999年   157394篇
  1998年   73122篇
  1997年   68469篇
  1996年   66849篇
  1995年   62074篇
  1994年   56284篇
  1993年   52244篇
  1992年   115675篇
  1991年   112195篇
  1990年   108175篇
  1989年   105574篇
  1988年   97496篇
  1987年   95674篇
  1986年   90586篇
  1985年   88568篇
  1984年   72900篇
  1983年   64972篇
  1982年   50091篇
  1981年   46638篇
  1980年   43792篇
  1979年   65113篇
  1978年   51999篇
  1977年   45306篇
  1976年   42395篇
  1975年   43451篇
  1974年   48739篇
  1973年   46916篇
  1972年   44247篇
  1971年   41242篇
排序方式: 共有10000条查询结果,搜索用时 953 毫秒
171.

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   
172.
173.
174.
175.
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   
176.
177.

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   
178.
179.
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