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   2537205篇
  免费   203941篇
  国内免费   16064篇
耳鼻咽喉   34700篇
儿科学   81802篇
妇产科学   69013篇
基础医学   356796篇
口腔科学   67529篇
临床医学   234824篇
内科学   493530篇
皮肤病学   55523篇
神经病学   200026篇
特种医学   98103篇
外国民族医学   1148篇
外科学   375720篇
综合类   82957篇
现状与发展   43篇
一般理论   800篇
预防医学   196310篇
眼科学   58264篇
药学   190176篇
  192篇
中国医学   15869篇
肿瘤学   143885篇
  2021年   26291篇
  2019年   24279篇
  2018年   32368篇
  2017年   25564篇
  2016年   27476篇
  2015年   33164篇
  2014年   45119篇
  2013年   61921篇
  2012年   85363篇
  2011年   90943篇
  2010年   54590篇
  2009年   50217篇
  2008年   80878篇
  2007年   85028篇
  2006年   85261篇
  2005年   82933篇
  2004年   77194篇
  2003年   73688篇
  2002年   71171篇
  2001年   119253篇
  2000年   122936篇
  1999年   104112篇
  1998年   30282篇
  1997年   27588篇
  1996年   27443篇
  1995年   26133篇
  1994年   24042篇
  1993年   21981篇
  1992年   78962篇
  1991年   76147篇
  1990年   73432篇
  1989年   69999篇
  1988年   64332篇
  1987年   62973篇
  1986年   58756篇
  1985年   56177篇
  1984年   42494篇
  1983年   35848篇
  1982年   21396篇
  1981年   19245篇
  1979年   37800篇
  1978年   26465篇
  1977年   22156篇
  1976年   20871篇
  1975年   22082篇
  1974年   26211篇
  1973年   25293篇
  1972年   23466篇
  1971年   21295篇
  1970年   20230篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
41.
Gold nanoparticles (Au NPs) hold great promise in food, industrial and biomedical applications due to their unique physicochemical properties. However, influences of the gastrointestinal tract (GIT), a likely route for Au NPs administration, on the physicochemical properties of Au NPs has been rarely evaluated. Here, we investigated the influence of GIT fluids on the physicochemical properties of Au NPs (5, 50, and 100?nm) and their implications on intestinal epithelial permeability in vitro. Au NPs aggregated in fasted gastric fluids and generated hydroxyl radicals in the presence of H2O2. Cell studies showed that GIT fluids incubation of Au NPs affected the cellular uptake of Au NPs but did not induce cytotoxicity or disturb the intestinal epithelial permeability.  相似文献   
42.
Introduction: The Hedgehog (HH) pathway constitutes a collection of signaling molecules which critically influence embryogenesis. In adults, however, the HH pathway remains integral to the proliferation, maintenance, and apoptosis of adult stem cells including hematopoietic stem cells.

Areas covered: We discuss the current understanding of the HH pathway as it relates to normal hematopoiesis, the pathology of acute myeloid leukemia (AML), the rationale for and data from combination therapies including HH pathway inhibitors, and ultimately the prospects that might offer promise in targeting this pathway in AML.

Expert opinion: Efforts to target the HH pathway have been focused on impeding this disposition and restoring chemosensitivity to conventional myeloid neoplasm therapies. The year 2018 saw the first approval of a HH pathway inhibitor (glasdegib) for AML, though for an older population and in combination with an uncommonly-used therapy. Several other clinical trials with agents targeting modulators of HH signaling in AML and MDS are underway. Further study and understanding of the interplay between the numerous aspects of HH signaling and how it relates to the augmented survival of AML will provide a more reliable substrate for therapeutic strategies in patients with this poor-risk disease.  相似文献   

43.
44.
45.
46.
BackgroundThe aim of this study was to estimate the prevalence of dental prosthetic treatment and to investigate the demographic, social, economic and medical factors associated with the use of fixed and removable dentures in a representative sample of adults living in France.MethodsThe data were obtained from the 2002–2003 Decennial Health Survey, a cross-sectional study of a representative sample of the population living in France, which included 29,679 adults. Information was collected by interview. The variables collected were fixed denture, removable denture, age, gender, number of children, area of residence, nationality, educational attainment, family social status, employment status, annual household income per capita, supplementary insurance, chronic disease, eyesight problems/glasses, hearing problems/hearing aids. Multinomial logistic regression models were used to study the relationship between prosthetic treatment and demographic, socioeconomic and medical characteristics unadjusted, adjusted for age and adjusted for all the characteristics.ResultsThe prevalence of prosthetic treatment was 34.6% (95% confidence interval (CI): [34.1; 35.2]) for fixed prosthetic dentures and 13.8% (95% CI: [13.4; 14.2]) for removable prosthetic dentures. We showed a gradient between educational attainment and removable dentures; the odds ratio adjusted for all the variables (aOR) associated with no or primary education compared to post-secondary education was 2.56; 95% CI: [2.09; 3.13]. When annual household income per capita was low, subjects were less likely to report fixed dentures (aOR = 0.68; 95% CI: [0.62; 0.75]) than those with high annual household income per capita. Individuals without insurance less often reported fixed dentures than those with private insurance. Those reporting chronic disease were less likely to report fixed dentures (aOR = 0.87; 95% CI: [0.79; 0.95]) but more likely to report removable dentures (aOR = 1.29; 95% CI: [1.17; 1.43]) than those without chronic disease.ConclusionThis study reveals social, economic and medical inequalities in fixed and removable prosthetic treatment among adults in France.  相似文献   
47.
48.
ABSTRACT

This project examined 55 picture books featuring transgender, gender expansive or genderqueer protagonists or narrators published between 2008 and 2018. The purpose of the study was to determine how this genre of children’s literature supports and challenges four gender assumptions: the gender binary, gender essentialism, sex/gender congruency and gender stability. Additionally, this critical analysis explored misgendering within this genre and themes of social rejection and acceptance. Protagonists and narrators were permitted a degree of gender nonconformity, however, the majority of picture books missed opportunities for a more complete exploration of gender possibilities.  相似文献   
49.
随着社会的发展,人类生活方式的改变,高血压病越来越高发,具有低龄化趋势,代谢综合征常伴随发生,此种情况下的高血压往往是以舒张压升高为主,临床表现常与“亚健康”状态混淆,未能引起患者甚至部分医生的重视,然而事实上越来越多的科学研究证实舒张压高之危害十分明显,不容忽视。尽管现代医学对舒张压高的病因及病理机制有明确的阐述,但是暂时没有特效的药物。李延教授在治疗高血压病方面有着丰富的临床经验,临床中运用泽泻汤合温胆汤加减治疗舒张压高之眩晕,切中病机,加减灵活,屡有良效。文中从中医角度阐述舒张压高的病因病机,介绍李师辨病辨证思路,组方用药特点,附三则典型验案,另加个人心得体会,以期为舒张压高的有效治疗提供思路。  相似文献   
50.
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