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   291953篇
  免费   17760篇
  国内免费   952篇
耳鼻咽喉   3445篇
儿科学   9112篇
妇产科学   5615篇
基础医学   39279篇
口腔科学   9675篇
临床医学   24491篇
内科学   63950篇
皮肤病学   5782篇
神经病学   25980篇
特种医学   9084篇
外国民族医学   27篇
外科学   38394篇
综合类   3038篇
现状与发展   2篇
一般理论   214篇
预防医学   28501篇
眼科学   6445篇
药学   18980篇
  1篇
中国医学   963篇
肿瘤学   17687篇
  2023年   1473篇
  2022年   2964篇
  2021年   5920篇
  2020年   3790篇
  2019年   5743篇
  2018年   7543篇
  2017年   5609篇
  2016年   5675篇
  2015年   6593篇
  2014年   9263篇
  2013年   12280篇
  2012年   18858篇
  2011年   20006篇
  2010年   10493篇
  2009年   9593篇
  2008年   16453篇
  2007年   17571篇
  2006年   16458篇
  2005年   16763篇
  2004年   15845篇
  2003年   14543篇
  2002年   12399篇
  2001年   6192篇
  2000年   5887篇
  1999年   5619篇
  1998年   2990篇
  1997年   2498篇
  1996年   2217篇
  1995年   2027篇
  1994年   1867篇
  1993年   1767篇
  1992年   3360篇
  1991年   3213篇
  1990年   2913篇
  1989年   2864篇
  1988年   2634篇
  1987年   2458篇
  1986年   2252篇
  1985年   2252篇
  1984年   1834篇
  1983年   1533篇
  1982年   1275篇
  1981年   1130篇
  1980年   1025篇
  1979年   1298篇
  1978年   957篇
  1977年   832篇
  1975年   821篇
  1974年   830篇
  1973年   813篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Background. The European Community Respiratory Health Survey (ECRHS) questionnaire was planned to answer questions about the distribution of asthma. Our objective was to determine the cultural equivalence of the ECRHS into the Brazilian-Portuguese language. Methods. We translated the ECRHS according to international criteria. Results. Small cultural adaptations were necessary. Among the 80 participating patients, the Cronbach indices were higher (0.98-1.00) and the Kappa indices varied from 0.77 to 1.00. Conclusion. The study suggests that the Brazilian version of the ECRHS is conceptually equivalent to the original and similarly reliable and may be used in international studies involving Portuguese-speaking respiratory patients.  相似文献   
62.
INTRODUCTION: To plan for future acceptance and implementation of computer-related technology, it is necessary to understand orthodontists' current perceptions and attitudes toward emerging technologies. METHODS: An anonymous, self-administered, mail-out survey of Canadian orthodontists was conducted. The response rate was 45.6% (304/667). RESULTS: Most orthodontists indicated that computer technology could improve current practice efficiency and quality of patient care. Only 15% reported that digital models are quite or very useful; 73.6%, 69.1%, 55%, and 37.4% agreed or strongly agreed with using digital and electronic technology to consult with other dental specialists, other orthodontists, general dentists, and the public, respectively. Cost of the technology was reported as a significant or insurmountable obstacle by 54% of the respondents. Interprovincial legislation, unclear consultation remuneration guidelines, and lack of comfort with the technology were not perceived as significant obstacles. Only 36% reported security or privacy issues as a significant or insurmountable obstacle. CONCLUSIONS: Canadian orthodontists seem to view digital and electronic technology as useful and capable of improving their offices' efficiency and production. Although they are sensitive to some potential obstacles, they are willing to overcome these and incorporate the technology into their practices.  相似文献   
63.
64.
The value of maternal C-reactive protein (CRP) levels as predictors of fetal and maternal infective morbidity and fetal mortality was assessed prospectively over a 6-month period in all cases of premature rupture of the fetal membranes or suspected premature labour. Statistical analysis of results showed that CRP at a level of 1.32 mg/dl is a sensitive marker of infective morbidity in mother and neonate. Furthermore, there was a significant association between raised CRP levels and low-birth-weight babies, suggesting that intra-uterine infection is a major cause of prematurity in the study population.  相似文献   
65.
66.
67.
68.
69.
70.
HYPOTHESIS: Based on recent findings on the association between vascular risk factors and hippocampal atrophy, we hypothesized that hypertension and diabetes mellitus (DM) are associated with medial temporal lobe atrophy (MTA) in subjects without disability, independent of the severity of white matter hyperintensities. METHODS: In the Leukoaraiosis And DISability in the elderly (LADIS) study, we investigated the relationships between DM, hypertension, blood pressure and MTA in 582 subjects, stratified by white matter hyperintensity severity, using multinomial logistic regression. MTA was visually scored for the left and right medial temporal lobe (score 0-4), and meaned. RESULTS: Mean age was 73.5 years (sd 5.1), 54% was female. Of the subjects, 15% had DM, and 70% had a history of hypertension. The likelihood of having MTA score 3 was significantly higher in subjects with DM (OR 2.9; 95% CI: 1.1-7.8) compared with an MTA score of 0 (no atrophy). The odds ratio for MTA score 2 was not significantly increased (OR 1.8; CI: 0.9-4). Systolic and diastolic blood pressure and a history of hypertension were not associated with MTA. There was no interaction between DM and hypertension. Stratification on white matter hyperintensities (WMH) did not alter the associations. CONCLUSION: Our study strengthens the observation that MTA is associated with DM, independently of the amount of small vessel disease as reflected by WMH.  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