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   619241篇
  免费   39598篇
  国内免费   2162篇
耳鼻咽喉   8324篇
儿科学   19436篇
妇产科学   17146篇
基础医学   100752篇
口腔科学   17786篇
临床医学   52463篇
内科学   112775篇
皮肤病学   14346篇
神经病学   43447篇
特种医学   22107篇
外国民族医学   66篇
外科学   91835篇
综合类   13534篇
一般理论   152篇
预防医学   46448篇
眼科学   14679篇
药学   49578篇
中国医学   1793篇
肿瘤学   34334篇
  2018年   6405篇
  2016年   5170篇
  2015年   5826篇
  2014年   7799篇
  2013年   11766篇
  2012年   16070篇
  2011年   17630篇
  2010年   10366篇
  2009年   9620篇
  2008年   16721篇
  2007年   17908篇
  2006年   18173篇
  2005年   17154篇
  2004年   16722篇
  2003年   15841篇
  2002年   15591篇
  2001年   30054篇
  2000年   31261篇
  1999年   25633篇
  1998年   7146篇
  1997年   5967篇
  1996年   5874篇
  1995年   5400篇
  1994年   5011篇
  1992年   19053篇
  1991年   19681篇
  1990年   19556篇
  1989年   18890篇
  1988年   17616篇
  1987年   17323篇
  1986年   16336篇
  1985年   15607篇
  1984年   11394篇
  1983年   9814篇
  1982年   5425篇
  1981年   4937篇
  1979年   11026篇
  1978年   7862篇
  1977年   6601篇
  1976年   6343篇
  1975年   7388篇
  1974年   8791篇
  1973年   8338篇
  1972年   8124篇
  1971年   7762篇
  1970年   7135篇
  1969年   6862篇
  1968年   6449篇
  1967年   5768篇
  1966年   5177篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Pharmaceutical Chemistry Journal - N-Substituted 4-aryl-2-hydroxy-4-oxobut-2-enoic acid hydrazides and their complexes with Ni(II), Mn(II), Co(II), Cu(II), and Zn(II) were prepared. Their...  相似文献   
62.
63.
64.
65.
66.
67.
68.

Background and aims

Since accelerated atherosclerosis has been reported in systemic lupus erythematosus (SLE), predictive biomarkers of cardiovascular disease (CVD) are needed. Among non-traditional risk factors, bone mineral density (BMD) has been related to CVD. However, its role in SLE remains controversial. This study aims to analyze the associations of subclinical atherosclerosis with traditional and non-traditional CV risk factors.

Methods and results

In a cross-sectional study, atherosclerosis burden was compared between 112 female SLE patients and 31 controls. Plaque number and carotid intima-media wall thickness (cIMT) were assessed by ultrasonography. In a retrospective study, BMD determinations obtained 5-years before the ultrasonography assessment were analyzed in a subgroup of 62 patients. Plaque frequency was increased in SLE, even in patients without CV events or carotid wall thickening. cIMT was increased in patients with CVD, positively correlated with body mass index (BMI). Interestingly, a paradoxical effect of BMI on carotid parameters was observed. Whereas underweight patients (BMI < 20) showed increased prevalence of carotid plaques with low cIMT, those with BMI > 30 showed higher cIMT and plaque burden. Overweight patients (25 < BMI<30) exhibited both elevated cIMT and plaque number. BMI was an independent predictor of BMD. In our retrospective study, patients with either clinical or subclinical CVD exhibited lower BMD levels than their CV-free counterparts. A low lumbar spine BMD independently predicted CVD development after adjusting for confounders.

Conclusion

SLE was associated with a higher subclinical atherosclerosis burden, a bimodal effect being observed for BMI. Decreased BMD can be a CV risk biomarker in SLE.  相似文献   
69.
The Latin American population has a double way of immigration, one toward the United States by proximity and another toward Spain by sociocultural affinity. This population increase is affecting organ donation and transplantation in receiving countries.

Objective

To analyze the brain death (BD) concept knowledge in the Dominican Republic immigrant population in Florida (United States) and Spain.

Method

Population under study: Population born in the Dominican Republic, resident in Florida (United States) and in Spain. Inclusion criteria: Population older than 15 years stratified by age and sex. Assessment instrument: Donation attitude questionnaire PCID-DTO-Ríos. Fieldwork: Random selection based on stratification. Immigration support association collaboration in Florida and Spain was needed to locate potential respondents. Completion was anonymous and self-administered, with verbal consent.

Results

A total of 123 respondents, 57 residents in Spain and 66 in Florida, have been included in the study. The 27% (n = 33) of the respondents knowledgeable of the BD concept consider it the death of an individual. Of the remainder, 52% (n = 64) do not know about it, and the remaining 21% (n = 26) believe it does not mean the death of a patient. No differences were observed regarding migration countries (P > .05). There was no association of the BD concept with other psychosocial factors analyzed or with the attitude toward organ donation.

Conclusions

Knowledge of the BD concept among the Dominican immigrant population is similar in Spain and Florida, and, unlike most studies, there is no objective association with the attitude toward organ donation.  相似文献   
70.
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