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   3596939篇
  免费   311308篇
  国内免费   14834篇
耳鼻咽喉   49688篇
儿科学   112860篇
妇产科学   90194篇
基础医学   562767篇
口腔科学   95953篇
临床医学   332804篇
内科学   644281篇
皮肤病学   95172篇
神经病学   312272篇
特种医学   143355篇
外国民族医学   305篇
外科学   562154篇
综合类   107330篇
现状与发展   93篇
一般理论   2376篇
预防医学   302720篇
眼科学   82518篇
药学   244904篇
  24篇
中国医学   9747篇
肿瘤学   171564篇
  2021年   56945篇
  2020年   38022篇
  2019年   59575篇
  2018年   75555篇
  2017年   58332篇
  2016年   64540篇
  2015年   78446篇
  2014年   115795篇
  2013年   181268篇
  2012年   101818篇
  2011年   102630篇
  2010年   123628篇
  2009年   129001篇
  2008年   89293篇
  2007年   92601篇
  2006年   103454篇
  2005年   98252篇
  2004年   99365篇
  2003年   89782篇
  2002年   78474篇
  2001年   112824篇
  2000年   105917篇
  1999年   103665篇
  1998年   68212篇
  1997年   65462篇
  1996年   63248篇
  1995年   58900篇
  1994年   52567篇
  1993年   49001篇
  1992年   74071篇
  1991年   70890篇
  1990年   67039篇
  1989年   65635篇
  1988年   60837篇
  1987年   59492篇
  1986年   56264篇
  1985年   56309篇
  1984年   50681篇
  1983年   45999篇
  1982年   42798篇
  1981年   40209篇
  1980年   37860篇
  1979年   41917篇
  1978年   36710篇
  1977年   33276篇
  1976年   30603篇
  1975年   29167篇
  1974年   30391篇
  1973年   29133篇
  1972年   27134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.
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   

10.
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