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   4384670篇
  免费   340527篇
  国内免费   16590篇
耳鼻咽喉   60515篇
儿科学   139756篇
妇产科学   114643篇
基础医学   669848篇
口腔科学   118685篇
临床医学   400001篇
内科学   794578篇
皮肤病学   108023篇
神经病学   370049篇
特种医学   170488篇
外国民族医学   767篇
外科学   658829篇
综合类   125301篇
现状与发展   28篇
一般理论   2622篇
预防医学   361853篇
眼科学   101609篇
药学   310380篇
  46篇
中国医学   13168篇
肿瘤学   220598篇
  2021年   56935篇
  2020年   36396篇
  2019年   59305篇
  2018年   74926篇
  2017年   57487篇
  2016年   63510篇
  2015年   76709篇
  2014年   111133篇
  2013年   176482篇
  2012年   125787篇
  2011年   130672篇
  2010年   126685篇
  2009年   128187篇
  2008年   116463篇
  2007年   123792篇
  2006年   132461篇
  2005年   126468篇
  2004年   127501篇
  2003年   117612篇
  2002年   106742篇
  2001年   168400篇
  2000年   163486篇
  1999年   149927篇
  1998年   72202篇
  1997年   67976篇
  1996年   65841篇
  1995年   61244篇
  1994年   55146篇
  1993年   51148篇
  1992年   107276篇
  1991年   101945篇
  1990年   97799篇
  1989年   95429篇
  1988年   87703篇
  1987年   85832篇
  1986年   80703篇
  1985年   78786篇
  1984年   65657篇
  1983年   58429篇
  1982年   47273篇
  1981年   43921篇
  1980年   41128篇
  1979年   55238篇
  1978年   44798篇
  1977年   40022篇
  1976年   36881篇
  1975年   36850篇
  1974年   39660篇
  1973年   37802篇
  1972年   35423篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
171.
172.
In 1963, Goffman argued that forming a group based on shared stigma may provide benefits. However, there is no empirical research on whether perception that a separate, unique, coherent group exists (i.e., group entitativity) influences coping, such as educating others or secrecy, for the stigmatized individual or his or her spouse. Further, little is known about how spouses influence each other in terms of promoting the education of others about a stigmatizing condition, especially when it comes to the role of believing that stigma-based groups, to which they may both belong, exist. This study provides a step toward bridging this gap in the research by applying the label management model in efforts to understand coping for couples in which one spouse is diagnosed with genetic mutations leading to alpha-1 antitrypsin deficiency (AATD). This study included 50 married couples in which one spouse is diagnosed with genetic mutations leading to alpha-1 antitrypsin deficiency (AATD). We found that group entitativity related to those with AATD counterbalanced the influence of genetic stigma on spouses’ intentions to keep the diagnosis secret or to educate others about it. Intrapersonal and interpersonal influences appeared among spouses. Attention is needed on the power of creating groups for stigmatized persons and their relatives. Indeed, people live within a dynamic world of group entities, and multiple social identities including spousal and familial. While attention has been paid to the diffusion of stigmas to loved ones, less has been paid to the uplift of group entities for them.  相似文献   
173.
174.
175.
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   
176.
177.
178.
179.
180.
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   
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