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   3768429篇
  免费   312354篇
  国内免费   14715篇
耳鼻咽喉   50800篇
儿科学   119523篇
妇产科学   97999篇
基础医学   591165篇
口腔科学   102396篇
临床医学   339888篇
内科学   672808篇
皮肤病学   98651篇
神经病学   316799篇
特种医学   147177篇
外国民族医学   267篇
外科学   582363篇
综合类   114001篇
现状与发展   24篇
一般理论   2361篇
预防医学   309340篇
眼科学   89146篇
药学   261371篇
  23篇
中国医学   11489篇
肿瘤学   187907篇
  2021年   56052篇
  2020年   35635篇
  2019年   58776篇
  2018年   73198篇
  2017年   55435篇
  2016年   61331篇
  2015年   75000篇
  2014年   109410篇
  2013年   174893篇
  2012年   105355篇
  2011年   107409篇
  2010年   121246篇
  2009年   124001篇
  2008年   93452篇
  2007年   98061篇
  2006年   107478篇
  2005年   102192篇
  2004年   103836篇
  2003年   93748篇
  2002年   83028篇
  2001年   136107篇
  2000年   129636篇
  1999年   122008篇
  1998年   68604篇
  1997年   65276篇
  1996年   63001篇
  1995年   58556篇
  1994年   52544篇
  1993年   48899篇
  1992年   85040篇
  1991年   80965篇
  1990年   76672篇
  1989年   75112篇
  1988年   69024篇
  1987年   67205篇
  1986年   63536篇
  1985年   62762篇
  1984年   54868篇
  1983年   49575篇
  1982年   43620篇
  1981年   40986篇
  1980年   38456篇
  1979年   44843篇
  1978年   38236篇
  1977年   34914篇
  1976年   31963篇
  1975年   30784篇
  1974年   32483篇
  1973年   31187篇
  1972年   29037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