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   3531627篇
  免费   294036篇
  国内免费   14165篇
耳鼻咽喉   47900篇
儿科学   112576篇
妇产科学   92338篇
基础医学   561139篇
口腔科学   93796篇
临床医学   317239篇
内科学   629473篇
皮肤病学   93288篇
神经病学   303815篇
特种医学   137855篇
外国民族医学   490篇
外科学   541131篇
综合类   107625篇
现状与发展   24篇
一般理论   2337篇
预防医学   297063篇
眼科学   80597篇
药学   241598篇
  22篇
中国医学   10471篇
肿瘤学   169051篇
  2021年   55163篇
  2020年   35131篇
  2019年   58150篇
  2018年   71613篇
  2017年   54711篇
  2016年   60482篇
  2015年   74345篇
  2014年   108572篇
  2013年   173662篇
  2012年   98889篇
  2011年   99384篇
  2010年   117848篇
  2009年   122232篇
  2008年   86198篇
  2007年   89811篇
  2006年   100270篇
  2005年   95555篇
  2004年   96981篇
  2003年   87427篇
  2002年   76886篇
  2001年   118110篇
  2000年   111567篇
  1999年   107512篇
  1998年   66639篇
  1997年   64233篇
  1996年   62074篇
  1995年   57522篇
  1994年   51464篇
  1993年   48034篇
  1992年   74191篇
  1991年   69865篇
  1990年   65607篇
  1989年   64402篇
  1988年   59365篇
  1987年   58076篇
  1986年   54614篇
  1985年   54411篇
  1984年   49485篇
  1983年   45057篇
  1982年   42165篇
  1981年   39542篇
  1980年   37232篇
  1979年   40221篇
  1978年   35565篇
  1977年   32274篇
  1976年   29611篇
  1975年   27937篇
  1974年   29006篇
  1973年   28026篇
  1972年   26228篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
171.
Context Withania somnifera (L.) Dunal is traditionally used for treating various ailments, but lacks scientific evaluation.

Objective This study evaluates Withania somnifera (WS) for its effect on platelet activity and inflammatory enzymes.

Materials and methods Aqueous and ethanolic (1:1) leaf extracts were subjected to in vitro indirect haemolytic activity using Naja naja venom, human platelet aggregation was quantified for lipid peroxidation using arachidonic acid (AA) as agonist and 5-lipoxygenase (5-LOX) levels were determined using standard spectrometric assays. Further, molecular docking was performed by the ligand fit method using molegro software package (Molegro ApS, Aarhus, Denmark).

Results The study found that aqueous and ethanol extracts have very negligible effect (15%) with an IC50 value of 13.8?mg/mL on PLA2 from Naja naja venom. Further, extracts of WS also had very little effect (18%) with an IC50 value of 16.6?mg/mL on malondialdehyde (MDA) formation. However, a 65% inhibition of 5-LOX with an IC50 value of 0.92?mg/mL was observed in 1:1 ethanol extracts. The same was evident from SAR model with the active ingredient withaferin A binding predominantly on Phe 77, Tyr 98, Arg 99, Asp 164, Leu 168, Ser 382, Arg 395, Tyr 396 and Tyr 614 with an atomic contact energy value of??128.96 compared to standard phenidone (?103.61). Thus, the current study validates the application of WS for inflammatory diseases.

Conclusion This study reveals the inhibitory potential of W. somnifera on inflammatory enzymes and platelet aggregation. Thus, WS can serve as a newer, safer and affordable medicine for inflammatory diseases.  相似文献   
172.
173.
174.
175.
176.
Esophageal adenocarcinoma is the fastest rising cancer in the United States. It develops from long‐standing gastroesophageal reflux disease which affects >20% of the general population. It carries a very poor prognosis with 5‐year survival <20%. The disease is known to sequentially progress from reflux esophagitis to a metaplastic precursor, Barrett''s esophagus and then onto dysplasia and esophageal adenocarcinoma. However, only few patients with reflux develop Barrett''s esophagus and only a minority of these turn malignant. The reason for this heterogeneity in clinical progression is unknown. To improve patient management, molecular changes which facilitate disease progression must be identified. Animal models can provide a comprehensive functional and anatomic platform for such a study. Rats and mice have been the most widely studied but disease homology with humans has been questioned. No animal model naturally simulates the inflammation to adenocarcinoma progression as in humans, with all models requiring surgical bypass or destruction of existing antireflux mechanisms. Valuable properties of individual models could be utilized to holistically evaluate disease progression. In this review paper, we critically examined the current animal models of Barrett''s esophagus, their differences and homologies with human disease and how they have shaped our current understanding of Barrett''s carcinogenesis.  相似文献   
177.
This study used the National Survey of Ambulatory Surgery (NSAS) database to measure the incidence of and risk factors for symptoms in the ambulatory surgery center and problems within 24 h after isolated carpal tunnel release (CTR). The NSAS contained records on 400,000 adult patients with carpal tunnel syndrome who were treated with CTR in 2006, based on ICD-9 codes. The type of anesthesia used and factors associated with symptoms and problems were sought in bivariate and multivariable statistical analyses. The mean duration of the procedure was 16 ± 8.8 min. Only 5 % were performed under local anesthesia without sedation, 45 % with IV sedation, 28 % regional anesthesia, and 19 % general anesthesia. Symptoms in the ambulatory surgery center or a problem within 24 h after discharge were recorded in 10 % of patients, all of them minor and transient, including difficulties with pain and its treatment. The strongest risk factors were male sex, age of 45 years and older, and participation of an anesthesiologist. Local anesthesia and regional anesthesia were associated with more perioperative symptoms and postoperative problems. Most CTR are performed with some sedation in the United States. CTR is a safe procedure: one in 10 patients will experience a minor issue in the perioperative or immediate postoperative period.  相似文献   
178.
179.
180.
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