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   2371833篇
  免费   198201篇
  国内免费   4206篇
耳鼻咽喉   34266篇
儿科学   72755篇
妇产科学   62936篇
基础医学   334899篇
口腔科学   67521篇
临床医学   215548篇
内科学   468621篇
皮肤病学   47929篇
神经病学   200814篇
特种医学   96005篇
外国民族医学   886篇
外科学   360406篇
综合类   56219篇
现状与发展   1篇
一般理论   977篇
预防医学   190654篇
眼科学   55467篇
药学   177542篇
  4篇
中国医学   4365篇
肿瘤学   126425篇
  2018年   24211篇
  2016年   20585篇
  2015年   23287篇
  2014年   33541篇
  2013年   50837篇
  2012年   68753篇
  2011年   72293篇
  2010年   42483篇
  2009年   40890篇
  2008年   68776篇
  2007年   73122篇
  2006年   74018篇
  2005年   72055篇
  2004年   69353篇
  2003年   67027篇
  2002年   66273篇
  2001年   112458篇
  2000年   116532篇
  1999年   98340篇
  1998年   27862篇
  1997年   25525篇
  1996年   25451篇
  1995年   24611篇
  1994年   23161篇
  1993年   21554篇
  1992年   79389篇
  1991年   76394篇
  1990年   73583篇
  1989年   70845篇
  1988年   65852篇
  1987年   64803篇
  1986年   61338篇
  1985年   58404篇
  1984年   44223篇
  1983年   37659篇
  1982年   22891篇
  1981年   20336篇
  1980年   19036篇
  1979年   41303篇
  1978年   28987篇
  1977年   24347篇
  1976年   22832篇
  1975年   23964篇
  1974年   29638篇
  1973年   28045篇
  1972年   26228篇
  1971年   24153篇
  1970年   22756篇
  1969年   21088篇
  1968年   19136篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
142.
143.
144.
Clinical Oral Investigations - The aims of this study are to assess different saliva substitutes for their efficacy to lubricate the oral cavity, and to relate this oral lubrication to the ability...  相似文献   
145.
146.
Background: Dense deposit disease and atypical hemolytic uremic syndrome are often caused by Complement Factor H (CFH) mutations. This study describes the retinal abnormalities in dense deposit disease and, for the first time, atypical haemolytic uremic syndrome. It also reviews our understanding of drusen pathogenesis and their relevance for glomerular disease. Methods: Six individuals with dense deposit disease and one with atypical haemolytic uremic syndrome were studied from 2 to 40 years after presentation. Five had renal transplants. All four who had genetic testing had CFH mutations. Individuals underwent ophthalmological review and retinal photography, and in some cases, optical coherence tomography, and further tests of retinal function. Results: All subjects with dense deposit disease had impaired night vision and retinal drusen or whitish-yellow deposits. Retinal atrophy, pigmentation, and hemorrhage were common. In late disease, peripheral vision was restricted, central vision was distorted, and there were scotoma from sub-retinal choroidal neovascular membranes and atypical serous retinopathy. Drusen were present but less prominent in the young person with atypical uremic syndrome due to a heterozygous CFH mutation. Conclusions: Drusen are common in forms of C3 glomerulopathy caused by compound heterozygous or heterozygous CFH mutations. They are useful diagnostically but also impair vision. Drusen have an identical composition to glomerular deposits. They are also identical to the drusen of age-related macular degeneration, and may respond to the same treatments. Individuals with a C3 glomerulopathy should be assessed ophthalmologically at diagnosis, and monitored regularly for vision-threatening complications.  相似文献   
147.
Obtaining accurate assessment data from adolescents in treatment aids clinical decision making and facilitates more accurate outcome evaluations. However, findings could be biased due to underreported substance use and mental health symptoms. This article compares self-reports of youth in non-White matched client–assessor dyads and those in nonmatched dyads. There were no differences on self-reported substance use, but matched youth reported significantly fewer attention deficit/hyperactivity disorder symptoms versus the comparison group. One possible reason for these findings is the effect of in-group stereotype threat. Future studies should examine the potential effect that in-group stereotyping and perceived racism have on the therapeutic relationship.  相似文献   
148.
149.
150.
This study explored the relationship between active mediation, exposure to Daniel Tiger’s Neighborhood, and key indicators of preschoolers’ social and emotional development. One hundred and twenty-seven children aged 2–6 either watched or did not watch 10 episodes of Daniel Tiger’s Neighborhood over a two-week period. Results revealed that preschoolers who watched the program exhibited higher levels of empathy, self-efficacy, and emotion recognition when their regular TV-watching experiences are frequently accompanied by active mediation. This was especially true for younger preschoolers and preschoolers from low-income families. Implications for policy-makers, parents, producers of prosocial programming, and educators are discussed.  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