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   1310934篇
  免费   96736篇
  国内免费   2049篇
耳鼻咽喉   18468篇
儿科学   43123篇
妇产科学   38599篇
基础医学   191816篇
口腔科学   36374篇
临床医学   112371篇
内科学   258817篇
皮肤病学   27114篇
神经病学   102570篇
特种医学   51131篇
外国民族医学   366篇
外科学   202482篇
综合类   26695篇
现状与发展   1篇
一般理论   323篇
预防医学   95787篇
眼科学   29508篇
药学   100482篇
  1篇
中国医学   2540篇
肿瘤学   71151篇
  2018年   12884篇
  2016年   11119篇
  2015年   12500篇
  2014年   17015篇
  2013年   26272篇
  2012年   35985篇
  2011年   38553篇
  2010年   22577篇
  2009年   21157篇
  2008年   37255篇
  2007年   40234篇
  2006年   40623篇
  2005年   39814篇
  2004年   38172篇
  2003年   37056篇
  2002年   36633篇
  2001年   58941篇
  2000年   60567篇
  1999年   51298篇
  1998年   14497篇
  1997年   13017篇
  1996年   13242篇
  1995年   12516篇
  1994年   11951篇
  1993年   11033篇
  1992年   41249篇
  1991年   40599篇
  1990年   40110篇
  1989年   38919篇
  1988年   36349篇
  1987年   35543篇
  1986年   33924篇
  1985年   32385篇
  1984年   24164篇
  1983年   21019篇
  1982年   12554篇
  1981年   11066篇
  1979年   22796篇
  1978年   16005篇
  1977年   13839篇
  1976年   13055篇
  1975年   14288篇
  1974年   16751篇
  1973年   16145篇
  1972年   15376篇
  1971年   14281篇
  1970年   13272篇
  1969年   12773篇
  1968年   12025篇
  1967年   10534篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
Background. Haemophagocytic lymphohistiocytosis (HLH) is a rare clinical syndrome characterized by fever, hepatosplenomegaly, cytopenia, and progressive multiple-organ failure. HLH in adults is often secondary to autoimmune diseases, cancer, or infections in contrast to familial HLH. Treatment of secondary HLH is directed against the triggering disease in addition to immunosuppressive therapy, the latter commonly according to the HLH-2004 protocol.Methods. We conducted a retrospective study to identify triggering diseases, disease-specific and immunosuppressive therapy administered, and prognosis in adult patients with secondary HLH. Patient data were collected from October 2010 to January 2015.Results. Ten adult patients with secondary HLH were identified. Seven were men, and the median age at diagnosis was 62 years. Five cases were triggered by malignant disease and five by infection. The median patient fulfilled five of the eight HLH-2004 diagnostic criteria. All patients fulfilled the criteria fever, cytopenia, and ferritin >500 µg/L. Median time from hospital admission to HLH diagnosis was 20 days. Four patients received immunosuppressive therapy according to the HLH-2004 protocol. The prognosis was dismal, especially for the patients with malignancy-associated HLH, of whom all died.Conclusion. HLH should be suspected in patients who present with fever, cytopenia, and ferritin >500 µg/L. Secondary HLH has a dismal prognosis. None of the patients with HLH triggered by malignancy survived. Achieving remission of the triggering disease seems to be important for a favourable outcome as, in all surviving patients, the haemophagocytic syndrome resolved after remission of the underlying infection.  相似文献   
83.
Breast elastography has been available for more than 15 years but is not widely incorporated into clinical practice. Many publications report extremely high accuracy for various breast elastographic techniques. However, results in the literature are extremely variable. This variability is most likely due to variations in technique, a relatively steep learning curve, and variability in methods between vendors. This article describes our protocol for performing breast elastography using both strain elastography and shear wave elastography, which produces high sensitivity and specificity. Additionally, we will describe the most commonly known false-positive and false-negative lesions as well as how to detect them.  相似文献   
84.
85.
86.
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   
87.
88.
89.
Graefe's Archive for Clinical and Experimental Ophthalmology - Retinal microvascular endothelial dysfunction is thought to be of importance in the development of ocular vascular diseases....  相似文献   
90.
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