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   2806494篇
  免费   247449篇
  国内免费   15209篇
耳鼻咽喉   38626篇
儿科学   84550篇
妇产科学   70662篇
基础医学   464421篇
口腔科学   75517篇
临床医学   247714篇
内科学   484248篇
皮肤病学   80075篇
神经病学   243837篇
特种医学   109907篇
外国民族医学   109篇
外科学   445477篇
综合类   91050篇
现状与发展   24篇
一般理论   2051篇
预防医学   229397篇
眼科学   64321篇
药学   193424篇
  23篇
中国医学   9832篇
肿瘤学   133887篇
  2022年   22780篇
  2021年   54540篇
  2020年   34839篇
  2019年   57722篇
  2018年   69522篇
  2017年   52880篇
  2016年   58317篇
  2015年   73193篇
  2014年   107263篇
  2013年   172101篇
  2012年   73340篇
  2011年   69744篇
  2010年   111018篇
  2009年   117219篇
  2008年   57267篇
  2007年   57797篇
  2006年   69590篇
  2005年   64750篇
  2004年   67036篇
  2003年   58548篇
  2002年   48578篇
  2001年   78959篇
  2000年   70538篇
  1999年   75732篇
  1998年   62683篇
  1997年   61066篇
  1996年   58162篇
  1995年   53644篇
  1994年   47734篇
  1993年   44752篇
  1992年   49333篇
  1991年   45882篇
  1990年   42710篇
  1989年   43162篇
  1988年   39894篇
  1987年   38732篇
  1986年   36540篇
  1985年   37293篇
  1984年   36954篇
  1983年   34699篇
  1982年   37564篇
  1981年   35674篇
  1980年   33681篇
  1979年   28058篇
  1978年   27408篇
  1977年   26155篇
  1976年   23237篇
  1975年   21245篇
  1974年   20173篇
  1973年   19214篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
152.
153.
154.

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   
155.
156.
157.
158.
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   
159.
160.

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   
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