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   3587790篇
  免费   254481篇
  国内免费   9313篇
耳鼻咽喉   50201篇
儿科学   118798篇
妇产科学   100661篇
基础医学   509402篇
口腔科学   101129篇
临床医学   321465篇
内科学   699431篇
皮肤病学   85315篇
神经病学   294126篇
特种医学   139339篇
外国民族医学   1087篇
外科学   540305篇
综合类   70852篇
现状与发展   6篇
一般理论   1258篇
预防医学   272756篇
眼科学   81860篇
药学   264621篇
  9篇
中国医学   7331篇
肿瘤学   191632篇
  2021年   28038篇
  2019年   28847篇
  2018年   41249篇
  2017年   31484篇
  2016年   36556篇
  2015年   40656篇
  2014年   55295篇
  2013年   83564篇
  2012年   112260篇
  2011年   118880篇
  2010年   71274篇
  2009年   67177篇
  2008年   111586篇
  2007年   119083篇
  2006年   120671篇
  2005年   116593篇
  2004年   111940篇
  2003年   108496篇
  2002年   105203篇
  2001年   162633篇
  2000年   166933篇
  1999年   140870篇
  1998年   41542篇
  1997年   36700篇
  1996年   36637篇
  1995年   35186篇
  1994年   32527篇
  1993年   30557篇
  1992年   109686篇
  1991年   106348篇
  1990年   103557篇
  1989年   100290篇
  1988年   92335篇
  1987年   90613篇
  1986年   85535篇
  1985年   81872篇
  1984年   60947篇
  1983年   52331篇
  1982年   31432篇
  1979年   55371篇
  1978年   39149篇
  1977年   33623篇
  1976年   31322篇
  1975年   33950篇
  1974年   39882篇
  1973年   38051篇
  1972年   36013篇
  1971年   33395篇
  1970年   31141篇
  1969年   29924篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
82.
83.

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   
84.
85.

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   
86.
87.
88.
Sorsby fundus dystrophy (SFD), an autosomal dominant, fully penetrant, degenerative disease of the macula, is manifested by symptoms of night blindness or sudden loss of visual acuity, usually in the third to fourth decades of life due to choroidal neovascularization (CNV). SFD is caused by specific mutations in the Tissue Inhibitor of Metalloproteinase-3, (TIMP3) gene. The predominant histo-pathological feature in the eyes of patients with SFD are confluent 20–30 m thick, amorphous deposits found between the basement membrane of the retinal pigment epithelium (RPE) and the inner collagenous layer of Bruch's membrane. SFD is a rare disease but it has generated significant interest because it closely resembles the exudative or “wet” form of the more common age-related macular degeneration (AMD). In addition, in both SFD and AMD donor eyes, sub-retinal deposits have been shown to accumulate TIMP3 protein. Understanding the molecular functions of wild-type and mutant TIMP3 will provide significant insights into the patho-physiology of SFD and perhaps AMD. This review summarizes the current knowledge on TIMP3 and how mutations in TIMP3 cause SFD to provide insights into how we can study this disease going forward. Findings from these studies could have potential therapeutic implications for both SFD and AMD.  相似文献   
89.
90.
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