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   2382296篇
  免费   199122篇
  国内免费   4259篇
耳鼻咽喉   34445篇
儿科学   73101篇
妇产科学   63137篇
基础医学   336370篇
口腔科学   67712篇
临床医学   216675篇
内科学   470934篇
皮肤病学   48096篇
神经病学   201587篇
特种医学   96409篇
外国民族医学   886篇
外科学   362267篇
综合类   56360篇
现状与发展   1篇
一般理论   985篇
预防医学   191246篇
眼科学   55908篇
药学   178209篇
  4篇
中国医学   4405篇
肿瘤学   126940篇
  2018年   24446篇
  2016年   20785篇
  2015年   23513篇
  2014年   33887篇
  2013年   51359篇
  2012年   69490篇
  2011年   73016篇
  2010年   42934篇
  2009年   41318篇
  2008年   69533篇
  2007年   73917篇
  2006年   74831篇
  2005年   72826篇
  2004年   70062篇
  2003年   67734篇
  2002年   66917篇
  2001年   112627篇
  2000年   116687篇
  1999年   98474篇
  1998年   27996篇
  1997年   25646篇
  1996年   25543篇
  1995年   24739篇
  1994年   23266篇
  1993年   21638篇
  1992年   79496篇
  1991年   76484篇
  1990年   73669篇
  1989年   70932篇
  1988年   65939篇
  1987年   64876篇
  1986年   61419篇
  1985年   58457篇
  1984年   44286篇
  1983年   37749篇
  1982年   22978篇
  1981年   20406篇
  1980年   19108篇
  1979年   41346篇
  1978年   29045篇
  1977年   24414篇
  1976年   22883篇
  1975年   24003篇
  1974年   29684篇
  1973年   28079篇
  1972年   26259篇
  1971年   24178篇
  1970年   22774篇
  1969年   21107篇
  1968年   19149篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
151.
152.
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   
153.
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   
154.
155.
156.
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   
157.
158.
On 8 April 2014, a US jury ordered Takeda and Eli Lilly to pay $9 bn in punitive damages after finding that they had concealed the cancer risks associated with pioglitazone. By contrast, on 28 August 2014, the long‐awaited outcome of the 10‐year Kaiser Permanente Northern California study was announced. That study was specifically designed to investigate whether patients exposed to pioglitazone were at an increased risk of bladder cancer and found no association; thus, at last, the controversial issue has been resolved. A review, in retrospect, of the story of the proposed link between pioglitazone and bladder cancer reveals flaws at every stage. In 2012, a BMJ editorial, in keeping with some other contemporary reports, stated ‘it can confidently be assumed that pioglitazone increases the risk of bladder cancer’. Examination of the information which led to such a statement shows that: 1) the pre‐clinical findings of bladder cancer in male rats is not indicative of human risk; 2) there is no association between bladder cancer and pioglitazone in randomized controlled trials, once cases that could not plausibly be related to treatment are removed; and 3) the observational studies that have suggested a link have over‐extrapolated from the data: pioglitazone‐treated patients had more risk factors for bladder cancer than those not treated with pioglitazone. Meanwhile careful study of randomized controlled trials shows evidence of cardiovascular benefit from pioglitazone in Type 2 diabetes, a condition which results, more than anything, in premature cardiovascular death and morbidity.  相似文献   
159.
160.
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