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   3556786篇
  免费   291564篇
  国内免费   14009篇
耳鼻咽喉   49285篇
儿科学   114391篇
妇产科学   91197篇
基础医学   560143篇
口腔科学   93259篇
临床医学   317930篇
内科学   637995篇
皮肤病学   93129篇
神经病学   303766篇
特种医学   140952篇
外国民族医学   692篇
外科学   550653篇
综合类   103996篇
现状与发展   24篇
一般理论   2385篇
预防医学   296854篇
眼科学   81184篇
药学   245439篇
  23篇
中国医学   9866篇
肿瘤学   169196篇
  2021年   55977篇
  2020年   35757篇
  2019年   59004篇
  2018年   72562篇
  2017年   55380篇
  2016年   61227篇
  2015年   75254篇
  2014年   109867篇
  2013年   175665篇
  2012年   100250篇
  2011年   101150篇
  2010年   119792篇
  2009年   123993篇
  2008年   88533篇
  2007年   92958篇
  2006年   102836篇
  2005年   98610篇
  2004年   100199篇
  2003年   91085篇
  2002年   80903篇
  2001年   110712篇
  2000年   104625篇
  1999年   103501篇
  1998年   66829篇
  1997年   64094篇
  1996年   61917篇
  1995年   57318篇
  1994年   51527篇
  1993年   48026篇
  1992年   73146篇
  1991年   70191篇
  1990年   66611篇
  1989年   65093篇
  1988年   60231篇
  1987年   59051篇
  1986年   55376篇
  1985年   55412篇
  1984年   50033篇
  1983年   45585篇
  1982年   42095篇
  1981年   39881篇
  1980年   37353篇
  1979年   40947篇
  1978年   35854篇
  1977年   32826篇
  1976年   30181篇
  1975年   29079篇
  1974年   29770篇
  1973年   28658篇
  1972年   26611篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
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   
152.
153.
154.
155.
156.
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   
157.
Arthroscopic acromioclavicular joint excision is a commonly performed but technically demanding procedure. Incomplete excision can leave residual symptoms. We present a simple, reproducible technique ensuring satisfactory excision of the joint.  相似文献   
158.
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   
159.
160.
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