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   2014899篇
  免费   168194篇
  国内免费   7696篇
耳鼻咽喉   27372篇
儿科学   62799篇
妇产科学   56665篇
基础医学   281448篇
口腔科学   57260篇
临床医学   180826篇
内科学   403133篇
皮肤病学   45723篇
神经病学   165550篇
特种医学   82262篇
外国民族医学   431篇
外科学   315893篇
综合类   51535篇
现状与发展   4篇
一般理论   660篇
预防医学   161616篇
眼科学   45333篇
药学   144475篇
  5篇
中国医学   3543篇
肿瘤学   104256篇
  2018年   19399篇
  2016年   18079篇
  2015年   20524篇
  2014年   28919篇
  2013年   43574篇
  2012年   55043篇
  2011年   58696篇
  2010年   35940篇
  2009年   34701篇
  2008年   55133篇
  2007年   59266篇
  2006年   60139篇
  2005年   58398篇
  2004年   56317篇
  2003年   54633篇
  2002年   52081篇
  2001年   91121篇
  2000年   93567篇
  1999年   78558篇
  1998年   24079篇
  1997年   21675篇
  1996年   22363篇
  1995年   22060篇
  1994年   20744篇
  1993年   19564篇
  1992年   65920篇
  1991年   64381篇
  1990年   62304篇
  1989年   59566篇
  1988年   55555篇
  1987年   54726篇
  1986年   51667篇
  1985年   50115篇
  1984年   38492篇
  1983年   32617篇
  1982年   20649篇
  1981年   18794篇
  1980年   17680篇
  1979年   36438篇
  1978年   26421篇
  1977年   22300篇
  1976年   20481篇
  1975年   21787篇
  1974年   26212篇
  1973年   25115篇
  1972年   23586篇
  1971年   21707篇
  1970年   20258篇
  1969年   19332篇
  1968年   17744篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
41.

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   
42.
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   
43.
44.
45.
46.
47.
48.
Henna, derived from a combination of natural leaves and coloring additives, is a common decorative dye traditionally used in many Islamic religious celebrations. Para‐phenylenediamine (PPD), a major component of black henna tattoo, is a strong sensitizer and common allergen. We report a case of severe connubial allergic contact dermatitis after black henna heterotransfer in a girl.  相似文献   
49.
50.
Owing to the frequent incidence of blast-induced traumatic brain injury (bTBI) in recent military conflicts, there is an urgent need to develop effective therapies for bTBI-related pathologies. Blood-brain barrier (BBB) breakdown has been reported to occur after primary blast exposure, making restoration of BBB function and integrity a promising therapeutic target. We tested the hypothesis that treatment with dexamethasone (DEX) after primary blast injury potentiates recovery of an in vitro BBB model consisting of mouse brain endothelial cells (bEnd.3). DEX treatment resulted in complete recovery of transendothelial electrical resistance and hydraulic conductivity 1 day after injury, compared with 3 days for vehicle-treated injured cultures. Administration of RU486 (mifepristone) inhibited effects of DEX, confirming that barrier restoration was mediated by glucocorticoid receptor signaling. Potentiated recovery with DEX treatment was accompanied by stronger zonula occludens (ZO)-1 tight junction immunostaining and expression, suggesting that increased ZO-1 expression was a structural correlate to BBB recovery after blast. Interestingly, augmented ZO-1 protein expression was associated with specific upregulation of the α+ isoform but not the α isoform. This is the first study to provide a mechanistic basis for potentiated functional recovery of an in vitro BBB model because of glucocorticoid treatment after primary blast injury.  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