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   237379篇
  免费   15093篇
  国内免费   997篇
耳鼻咽喉   2555篇
儿科学   6009篇
妇产科学   4428篇
基础医学   29690篇
口腔科学   4349篇
临床医学   24282篇
内科学   50073篇
皮肤病学   3242篇
神经病学   24082篇
特种医学   10158篇
外国民族医学   13篇
外科学   37221篇
综合类   2551篇
现状与发展   1篇
一般理论   177篇
预防医学   16678篇
眼科学   5569篇
药学   15699篇
  1篇
中国医学   319篇
肿瘤学   16372篇
  2023年   1357篇
  2022年   2215篇
  2021年   5396篇
  2020年   3110篇
  2019年   5115篇
  2018年   6125篇
  2017年   4493篇
  2016年   4899篇
  2015年   5783篇
  2014年   8415篇
  2013年   11339篇
  2012年   17387篇
  2011年   18114篇
  2010年   10126篇
  2009年   9378篇
  2008年   15940篇
  2007年   16740篇
  2006年   16284篇
  2005年   16150篇
  2004年   15204篇
  2003年   13873篇
  2002年   13272篇
  2001年   2012篇
  2000年   1499篇
  1999年   2074篇
  1998年   2812篇
  1997年   2239篇
  1996年   1944篇
  1995年   1778篇
  1994年   1547篇
  1993年   1504篇
  1992年   1033篇
  1991年   968篇
  1990年   823篇
  1989年   777篇
  1988年   722篇
  1987年   641篇
  1986年   664篇
  1985年   716篇
  1984年   934篇
  1983年   808篇
  1982年   1051篇
  1981年   977篇
  1980年   849篇
  1979年   487篇
  1978年   526篇
  1977年   458篇
  1976年   428篇
  1975年   321篇
  1974年   317篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
44.
45.
The objective of this study was to investigate the effect of fluoridated elastomeric ligatures on the microbiology of local dental plaque in vivo. This randomized, prospective, longitudinal, clinical trial had a split-mouth crossover design. The subjects were 30 patients at the beginning of their treatment with fixed orthodontic appliances in the orthodontic departments of the Liverpool and the Sheffield dental hospitals in the United Kingdom. The study consisted of 2 experimental periods of 6 weeks with a washout period between. Fluoridated elastomers were randomly allocated at the first visit to be placed around brackets on tooth numbers 12, 11, 33 or 22, 21, 43. Nonfluoridated elastomers were placed on the contralateral teeth. Standard nonantibacterial fluoridated toothpaste and mouthwash were supplied. After 6 weeks (visit 2), the elastomers were removed, placed in transport media, and plated on agar within 2 hours. Nonfluoridated elastomers were placed on all brackets for 1 visit to allow for a washout period. At visit 3, fluoridated elastomers were placed on the teeth contralateral to those that received them at visit 1. At visit 4, the procedures at visit 2 were repeated. Samples were collected on visits 2 and 4. A logistic regression was performed, with the presence or absence of streptococcal or anaerobic growth as the dependent variable. A mixed-effects analysis of variance was carried out with the percentage of streptococcal or anaerobic bacterial count as the dependent variable. The only significant independent variables were the subject variable (P =<.001) for the percentage of streptococcal and anaerobic bacterial count and the visit variable for the percentage of streptococcal count (P =<.001). The use of fluoridated or nonfluoridated elastomers was not significant for percentage of either streptococcal (P =.288) or anaerobic count (P =.230). Fluoridated elastomers are not effective at reducing local streptococcal or anaerobic bacterial growth after a clinically relevant time in the mouth.  相似文献   
46.
This research was conducted at a summer camp for siblings of children with cancer. The camp is designed to address emotional problems, provide peer interaction and validation, and bolster siblings' self-esteem. Standardized measures assessing posttraumatic stress, anxiety, quality of life, and self-esteem were administered to 77 siblings (ages 6-17) prior to attending camp and again 3 months after camp. From pre- to post-camp, the siblings reported statistically significant decreases in symptoms of posttraumatic stress and anxiety, and statistically significant improvements in quality of life and self-esteem. These preliminary findings are encouraging and suggest the value of camp as a psychological intervention and provide a model for other pediatric cancer facilities designing intervention programs for siblings.  相似文献   
47.
48.
The value of a long-term treatment with clonazepam in the prophylaxis of affective disorder is discussed controversially in the scientific literature. Altogether there are only a few reports on the use of this compound as a mood stabilizer, most of them describing patients suffering from bipolar affective disorder. The aim of this investigation was to evaluate clonazepam as a phase prophylactic medication in affective disorder. We conducted a retrospective chart review in 34 out-patients of our lithium clinic (15 suffering from unipolar depression, 15 from bipolar disorder, four from schizoaffective disorder), who had been treated with clonazepam as a long-term medication. Clonazepam was either given as monotherapy, or as in the case of lithium non-responders, as adjunctive therapy. Patients with unipolar depression had significantly (P=0.026) less depressive episodes after initiation of treatment with clonazepam. Patients with bipolar disorder did not benefit from this therapy. Neither manic/hypomanic phases nor depressive episodes were reduced in this group of patients. Interestingly, clonazepam also reduced affective phases in our four schizoaffective patients on a trend level. Our results indicate that patients with unipolar depression may benefit from a maintenance treatment with clonazepam. Due to methodological limitations our results need to be replicated in controlled double-blind randomized clinical trials.  相似文献   
49.
50.
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