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   4001116篇
  免费   333324篇
  国内免费   15006篇
耳鼻咽喉   55486篇
儿科学   128369篇
妇产科学   106568篇
基础医学   621374篇
口腔科学   108356篇
临床医学   358483篇
内科学   724881篇
皮肤病学   101604篇
神经病学   340191篇
特种医学   157444篇
外国民族医学   797篇
外科学   615943篇
综合类   119569篇
现状与发展   24篇
一般理论   2477篇
预防医学   332254篇
眼科学   92578篇
药学   277248篇
  19篇
中国医学   11436篇
肿瘤学   194345篇
  2021年   55553篇
  2020年   35388篇
  2019年   58492篇
  2018年   72821篇
  2017年   55465篇
  2016年   61414篇
  2015年   74813篇
  2014年   109108篇
  2013年   174374篇
  2012年   112147篇
  2011年   115377篇
  2010年   121939篇
  2009年   125029篇
  2008年   102149篇
  2007年   107904篇
  2006年   117246篇
  2005年   112843篇
  2004年   113794篇
  2003年   104170篇
  2002年   93599篇
  2001年   142462篇
  2000年   137091篇
  1999年   128453篇
  1998年   69361篇
  1997年   66210篇
  1996年   64037篇
  1995年   59449篇
  1994年   53366篇
  1993年   49700篇
  1992年   91208篇
  1991年   86436篇
  1990年   82414篇
  1989年   80309篇
  1988年   74350篇
  1987年   72795篇
  1986年   69062篇
  1985年   67980篇
  1984年   58906篇
  1983年   52966篇
  1982年   45390篇
  1981年   42242篇
  1980年   39823篇
  1979年   49840篇
  1978年   41685篇
  1977年   37226篇
  1976年   34493篇
  1975年   33720篇
  1974年   36418篇
  1973年   35132篇
  1972年   32985篇
排序方式: 共有10000条查询结果,搜索用时 359 毫秒
171.
172.
173.
174.

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   
175.
176.
177.
178.
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   
179.
180.

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