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   3694510篇
  免费   320517篇
  国内免费   13707篇
耳鼻咽喉   50883篇
儿科学   118280篇
妇产科学   97207篇
基础医学   580608篇
口腔科学   102694篇
临床医学   330927篇
内科学   660307篇
皮肤病学   95174篇
神经病学   316773篇
特种医学   148520篇
外国民族医学   497篇
外科学   572080篇
综合类   113681篇
现状与发展   23篇
一般理论   2375篇
预防医学   307472篇
眼科学   85699篇
药学   259525篇
  21篇
中国医学   10122篇
肿瘤学   175866篇
  2021年   55030篇
  2020年   35082篇
  2019年   57989篇
  2018年   71411篇
  2017年   54110篇
  2016年   59926篇
  2015年   73871篇
  2014年   108186篇
  2013年   173284篇
  2012年   97170篇
  2011年   97562篇
  2010年   117716篇
  2009年   122057篇
  2008年   85342篇
  2007年   88643篇
  2006年   99590篇
  2005年   94701篇
  2004年   97313篇
  2003年   87777篇
  2002年   77641篇
  2001年   120841篇
  2000年   115134篇
  1999年   111699篇
  1998年   67007篇
  1997年   64578篇
  1996年   62571篇
  1995年   58188篇
  1994年   52344篇
  1993年   48884篇
  1992年   82935篇
  1991年   79399篇
  1990年   75949篇
  1989年   74613篇
  1988年   69446篇
  1987年   68137篇
  1986年   64930篇
  1985年   64808篇
  1984年   56582篇
  1983年   51284篇
  1982年   44754篇
  1981年   41913篇
  1980年   39514篇
  1979年   48962篇
  1978年   40957篇
  1977年   36775篇
  1976年   34075篇
  1975年   32836篇
  1974年   35535篇
  1973年   34194篇
  1972年   31691篇
排序方式: 共有10000条查询结果,搜索用时 15 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