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   2221755篇
  免费   170834篇
  国内免费   7360篇
耳鼻咽喉   29731篇
儿科学   71317篇
妇产科学   60095篇
基础医学   309109篇
口腔科学   62193篇
临床医学   199930篇
内科学   441278篇
皮肤病学   52207篇
神经病学   177577篇
特种医学   90505篇
外国民族医学   472篇
外科学   344019篇
综合类   49556篇
现状与发展   3篇
一般理论   661篇
预防医学   169162篇
眼科学   48887篇
药学   165291篇
  10篇
中国医学   4555篇
肿瘤学   123391篇
  2018年   22570篇
  2017年   17857篇
  2016年   21005篇
  2015年   23394篇
  2014年   32357篇
  2013年   48131篇
  2012年   61451篇
  2011年   65633篇
  2010年   40088篇
  2009年   38630篇
  2008年   61256篇
  2007年   65398篇
  2006年   66849篇
  2005年   64152篇
  2004年   61401篇
  2003年   59539篇
  2002年   57087篇
  2001年   112495篇
  2000年   115856篇
  1999年   96719篇
  1998年   26916篇
  1997年   23944篇
  1996年   24714篇
  1995年   24299篇
  1994年   22475篇
  1993年   21174篇
  1992年   77276篇
  1991年   74914篇
  1990年   72729篇
  1989年   69821篇
  1988年   63987篇
  1987年   62685篇
  1986年   59109篇
  1985年   56499篇
  1984年   42123篇
  1983年   35448篇
  1982年   21105篇
  1981年   18689篇
  1980年   17678篇
  1979年   37894篇
  1978年   26658篇
  1977年   23044篇
  1976年   20691篇
  1975年   22347篇
  1974年   26140篇
  1973年   25147篇
  1972年   23536篇
  1971年   21875篇
  1970年   20022篇
  1969年   19008篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.

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   
52.
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   
53.
54.
55.
56.
57.
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   
58.
59.
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   
60.
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