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   3154879篇
  免费   235531篇
  国内免费   4746篇
耳鼻咽喉   44837篇
儿科学   104989篇
妇产科学   85890篇
基础医学   459070篇
口腔科学   86775篇
临床医学   284184篇
内科学   611598篇
皮肤病学   69648篇
神经病学   249549篇
特种医学   120015篇
外国民族医学   1096篇
外科学   477561篇
综合类   67338篇
现状与发展   12篇
一般理论   1118篇
预防医学   246869篇
眼科学   74016篇
药学   235435篇
  12篇
中国医学   6132篇
肿瘤学   169012篇
  2019年   24978篇
  2018年   34783篇
  2017年   26152篇
  2016年   29281篇
  2015年   33021篇
  2014年   46526篇
  2013年   70303篇
  2012年   96778篇
  2011年   103023篇
  2010年   61462篇
  2009年   58158篇
  2008年   97101篇
  2007年   103744篇
  2006年   104670篇
  2005年   101410篇
  2004年   97693篇
  2003年   94260篇
  2002年   91751篇
  2001年   144758篇
  2000年   149000篇
  1999年   126084篇
  1998年   36519篇
  1997年   32180篇
  1996年   32561篇
  1995年   30888篇
  1994年   28722篇
  1993年   26837篇
  1992年   98554篇
  1991年   96556篇
  1990年   93999篇
  1989年   90220篇
  1988年   83038篇
  1987年   81829篇
  1986年   76471篇
  1985年   73601篇
  1984年   55015篇
  1983年   46714篇
  1982年   27728篇
  1981年   24978篇
  1979年   50370篇
  1978年   35735篇
  1977年   30012篇
  1976年   28484篇
  1975年   30773篇
  1974年   36493篇
  1973年   34925篇
  1972年   32575篇
  1971年   30486篇
  1970年   28421篇
  1969年   26753篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
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   
33.
34.
35.
36.
37.
MicroRNAs (miRNAs) play important roles in prostate cancer development. However, it remains unclear how individual miRNAs contribute to the initiation and progression of prostate cancer. Here we show that a basal layer‐enriched miRNA is required for prostate tumorigenesis. We identify miR‐205 as the most highly expressed miRNA and enriched in the basal cells of the prostate. Although miR‐205 is not required for normal prostate development and homeostasis, genetic deletion of miR‐205 in a Pten null tumor model significantly compromises tumor progression and does not promote metastasis. In Pten null basal cells, loss of miR‐205 attenuates pAkt levels and promotes cellular senescence. Furthermore, although overexpression of miR‐205 in prostate cancer cells with luminal phenotypes inhibits cell growth in both human and mouse, miR‐205 has a minimal effect on the growth of a normal human prostate cell line. Taken together, we have provided genetic evidence for a requirement of miR‐205 in the progression of Pten null‐induced prostate cancer.  相似文献   
38.
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   
39.
40.
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