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   3584020篇
  免费   286390篇
  国内免费   14969篇
耳鼻咽喉   49307篇
儿科学   109311篇
妇产科学   93144篇
基础医学   559086篇
口腔科学   98995篇
临床医学   317935篇
内科学   637396篇
皮肤病学   94742篇
神经病学   307070篇
特种医学   142191篇
外国民族医学   459篇
外科学   556704篇
综合类   108358篇
现状与发展   25篇
一般理论   2369篇
预防医学   291677篇
眼科学   81832篇
药学   250050篇
  23篇
中国医学   10547篇
肿瘤学   174158篇
  2021年   55858篇
  2020年   35720篇
  2019年   58917篇
  2018年   72154篇
  2017年   55171篇
  2016年   61154篇
  2015年   75178篇
  2014年   109798篇
  2013年   175599篇
  2012年   97912篇
  2011年   97942篇
  2010年   118515篇
  2009年   123267篇
  2008年   85398篇
  2007年   89614篇
  2006年   99809篇
  2005年   95271篇
  2004年   96941篇
  2003年   88065篇
  2002年   78080篇
  2001年   109892篇
  2000年   102869篇
  1999年   101879篇
  1998年   65912篇
  1997年   63680篇
  1996年   61076篇
  1995年   56494篇
  1994年   50671篇
  1993年   47348篇
  1992年   72010篇
  1991年   68292篇
  1990年   65196篇
  1989年   64547篇
  1988年   60418篇
  1987年   59060篇
  1986年   56487篇
  1985年   56150篇
  1984年   50661篇
  1983年   45937篇
  1982年   42501篇
  1981年   39980篇
  1980年   37771篇
  1979年   43051篇
  1978年   37459篇
  1977年   34389篇
  1976年   31148篇
  1975年   30806篇
  1974年   32497篇
  1973年   31148篇
  1972年   29575篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
BackgroundLittle is known about the extent of ordering low-value services by.PurposeTo compare the rates of low-value back images ordered by primary care physicians (PCMDs) and primary care nurse practitioners (PCNPs).MethodWe used 2012 and 2013 Medicare Part B claims for all beneficiaries in 18 hospital referral ?regions (HRRs) and a measure of low-value back imaging from Choosing Wisely. Models included random clinician effect and fixed effects for beneficiary age, disability, Elixhauser comorbidities, clinician sex, the emergency department setting, back pain visit volume, organization, and region (HRR).FindingsPCNPs (N = 231) and PCMDs (N = 4,779) order low-value back images at similar rates (NP: all images: 26.5%; MRI/CT: 8.4%; MD: all images: 24.5%; MRI/CT: 7.7%), with no detectable significant difference when controlling for covariates.DiscussionPCNPs and PCMDs order low-value back images at an effectively similar rate.  相似文献   
2.
3.
4.
5.
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   
6.
7.
8.
9.
10.
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   

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