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   4073633篇
  免费   340215篇
  国内免费   14996篇
耳鼻咽喉   56017篇
儿科学   132210篇
妇产科学   108411篇
基础医学   634373篇
口腔科学   111070篇
临床医学   369954篇
内科学   732976篇
皮肤病学   103856篇
神经病学   346016篇
特种医学   159587篇
外国民族医学   776篇
外科学   620246篇
综合类   122715篇
现状与发展   24篇
一般理论   2562篇
预防医学   341197篇
眼科学   94873篇
药学   282902篇
  18篇
中国医学   11632篇
肿瘤学   197429篇
  2021年   55742篇
  2020年   35553篇
  2019年   58641篇
  2018年   73379篇
  2017年   55909篇
  2016年   61928篇
  2015年   75121篇
  2014年   109573篇
  2013年   175047篇
  2012年   114820篇
  2011年   118611篇
  2010年   123094篇
  2009年   125596篇
  2008年   104825篇
  2007年   110815篇
  2006年   120140篇
  2005年   115135篇
  2004年   116428篇
  2003年   106484篇
  2002年   95662篇
  2001年   147259篇
  2000年   142027篇
  1999年   132068篇
  1998年   70194篇
  1997年   66706篇
  1996年   64594篇
  1995年   60059篇
  1994年   54113篇
  1993年   50242篇
  1992年   94496篇
  1991年   90141篇
  1990年   86007篇
  1989年   83916篇
  1988年   77148篇
  1987年   76135篇
  1986年   71604篇
  1985年   70642篇
  1984年   60815篇
  1983年   54259篇
  1982年   46132篇
  1981年   43001篇
  1980年   40387篇
  1979年   51641篇
  1978年   43082篇
  1977年   38299篇
  1976年   35478篇
  1975年   34617篇
  1974年   37605篇
  1973年   36374篇
  1972年   33849篇
排序方式: 共有10000条查询结果,搜索用时 46 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