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   4248268篇
  免费   343819篇
  国内免费   13982篇
耳鼻咽喉   59241篇
儿科学   135787篇
妇产科学   111374篇
基础医学   656994篇
口腔科学   114299篇
临床医学   386150篇
内科学   767324篇
皮肤病学   106735篇
神经病学   354281篇
特种医学   165314篇
外国民族医学   505篇
外科学   654744篇
综合类   120002篇
现状与发展   23篇
一般理论   2654篇
预防医学   353641篇
眼科学   99507篇
药学   297660篇
  23篇
中国医学   11378篇
肿瘤学   208433篇
  2021年   56597篇
  2020年   35981篇
  2019年   59079篇
  2018年   74601篇
  2017年   56580篇
  2016年   62815篇
  2015年   75794篇
  2014年   110406篇
  2013年   175824篇
  2012年   125117篇
  2011年   130890篇
  2010年   126915篇
  2009年   127876篇
  2008年   116304篇
  2007年   123919篇
  2006年   132438篇
  2005年   127467篇
  2004年   127417篇
  2003年   117666篇
  2002年   106721篇
  2001年   150083篇
  2000年   144894篇
  1999年   134639篇
  1998年   70396篇
  1997年   66426篇
  1996年   64603篇
  1995年   59862篇
  1994年   53940篇
  1993年   50191篇
  1992年   96292篇
  1991年   92865篇
  1990年   89291篇
  1989年   86999篇
  1988年   80213篇
  1987年   78691篇
  1986年   74011篇
  1985年   73122篇
  1984年   61800篇
  1983年   55540篇
  1982年   46102篇
  1981年   43197篇
  1980年   40572篇
  1979年   53230篇
  1978年   44113篇
  1977年   38975篇
  1976年   36332篇
  1975年   36333篇
  1974年   39493篇
  1973年   37716篇
  1972年   35309篇
排序方式: 共有10000条查询结果,搜索用时 125 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