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   1977648篇
  免费   155953篇
  国内免费   3573篇
耳鼻咽喉   29183篇
儿科学   64685篇
妇产科学   55396篇
基础医学   283405篇
口腔科学   55421篇
临床医学   172883篇
内科学   387410篇
皮肤病学   42081篇
神经病学   157516篇
特种医学   79079篇
外国民族医学   825篇
外科学   306400篇
综合类   47965篇
现状与发展   3篇
一般理论   600篇
预防医学   151990篇
眼科学   45810篇
药学   147519篇
  2篇
中国医学   3789篇
肿瘤学   105212篇
  2018年   19049篇
  2016年   16149篇
  2015年   18544篇
  2014年   26232篇
  2013年   40106篇
  2012年   54629篇
  2011年   57597篇
  2010年   34293篇
  2009年   32420篇
  2008年   54979篇
  2007年   59348篇
  2006年   59437篇
  2005年   58102篇
  2004年   56965篇
  2003年   55162篇
  2002年   53762篇
  2001年   90552篇
  2000年   93539篇
  1999年   79371篇
  1998年   22586篇
  1997年   20552篇
  1996年   20704篇
  1995年   19598篇
  1994年   18706篇
  1993年   17453篇
  1992年   64695篇
  1991年   63274篇
  1990年   61698篇
  1989年   59077篇
  1988年   54843篇
  1987年   54005篇
  1986年   50614篇
  1985年   48854篇
  1984年   37177篇
  1983年   31515篇
  1982年   18945篇
  1981年   17379篇
  1980年   15877篇
  1979年   35178篇
  1978年   24890篇
  1977年   21054篇
  1976年   19556篇
  1975年   21307篇
  1974年   25426篇
  1973年   24523篇
  1972年   22942篇
  1971年   21029篇
  1970年   19915篇
  1969年   18732篇
  1968年   16966篇
排序方式: 共有10000条查询结果,搜索用时 20 毫秒
21.
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   
22.
23.
24.
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   
25.
26.
Background: Traumatic brain injury (TBI) results in verbal recall deficits and impaired processing of emotion encoded in facial appearance, prosody and the linguistic content of messages. Emotion facilitates memory (emotional memory advantage) for non-brain injured (NBI) individuals but the impact of emotion on verbal recall for linguistically encoded stimuli in TBI has not been explored.

Aims: The purpose of this study was to determine the effects of stimulus emotional content on verbal recall of words and paragraphs in TBI compared to NBI individuals.

Methods and procedures: Six 10-item lists, each with five emotional and five neutral words, and six paragraphs (three emotional, three neutral) were counterbalanced and presented in random order to 20 individuals with TBI and 44 NBI. The number of words from lists and the number of content units from paragraphs were compared for the two groups.

Outcomes and results: The NBI participants recalled more words from the lists and content units from the paragraphs than the individuals with TBI. Both groups recalled significantly more emotional than neutral words. NBI but not TBI participants had significantly greater recall for information in paragraphs with emotional content.

Conclusions: Participants with TBI showed impaired recall of words and paragraph content. Emotion facilitated word and paragraph content recall for neurotypical individuals but emotional memory advantage was limited to words for the TBI participants.  相似文献   

27.
28.
29.
30.
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