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   3587988篇
  免费   318020篇
  国内免费   19466篇
耳鼻咽喉   49734篇
儿科学   109954篇
妇产科学   92698篇
基础医学   562650篇
口腔科学   100829篇
临床医学   323335篇
内科学   639678篇
皮肤病学   96907篇
神经病学   307424篇
特种医学   142006篇
外国民族医学   501篇
外科学   557781篇
综合类   119252篇
现状与发展   43篇
一般理论   2279篇
预防医学   290680篇
眼科学   82943篇
药学   254043篇
  60篇
中国医学   15006篇
肿瘤学   177671篇
  2021年   58530篇
  2020年   39864篇
  2019年   65315篇
  2018年   77071篇
  2017年   60671篇
  2016年   66635篇
  2015年   81625篇
  2014年   116268篇
  2013年   181110篇
  2012年   96807篇
  2011年   96260篇
  2010年   122086篇
  2009年   125137篇
  2008年   81663篇
  2007年   84834篇
  2006年   95386篇
  2005年   90567篇
  2004年   91824篇
  2003年   82972篇
  2002年   73048篇
  2001年   113559篇
  2000年   106671篇
  1999年   104946篇
  1998年   66721篇
  1997年   64261篇
  1996年   61359篇
  1995年   56746篇
  1994年   50908篇
  1993年   47413篇
  1992年   73402篇
  1991年   69409篇
  1990年   66342篇
  1989年   65539篇
  1988年   61307篇
  1987年   59764篇
  1986年   57144篇
  1985年   56684篇
  1984年   50931篇
  1983年   46135篇
  1982年   42471篇
  1981年   39893篇
  1980年   37709篇
  1979年   43168篇
  1978年   37400篇
  1977年   34305篇
  1976年   31082篇
  1975年   30723篇
  1974年   32455篇
  1973年   31138篇
  1972年   29548篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
181.
182.

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   
183.
184.
185.
186.
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   
187.
188.

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   
189.
190.
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