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   3145215篇
  免费   233736篇
  国内免费   8743篇
耳鼻咽喉   43678篇
儿科学   101678篇
妇产科学   88210篇
基础医学   444331篇
口腔科学   88264篇
临床医学   284689篇
内科学   615280篇
皮肤病学   73555篇
神经病学   257934篇
特种医学   122100篇
外国民族医学   885篇
外科学   474993篇
综合类   68944篇
现状与发展   7篇
一般理论   1159篇
预防医学   242602篇
眼科学   71571篇
药学   231309篇
  8篇
中国医学   6407篇
肿瘤学   170090篇
  2018年   33581篇
  2017年   25902篇
  2016年   29958篇
  2015年   33990篇
  2014年   47075篇
  2013年   71097篇
  2012年   94104篇
  2011年   99398篇
  2010年   59779篇
  2009年   57224篇
  2008年   93017篇
  2007年   99275篇
  2006年   100777篇
  2005年   96982篇
  2004年   93739篇
  2003年   90716篇
  2002年   87373篇
  2001年   147265篇
  2000年   150618篇
  1999年   127306篇
  1998年   37115篇
  1997年   33149篇
  1996年   33147篇
  1995年   32019篇
  1994年   29546篇
  1993年   27734篇
  1992年   100624篇
  1991年   97076篇
  1990年   94287篇
  1989年   91141篇
  1988年   83793篇
  1987年   82335篇
  1986年   77393篇
  1985年   74050篇
  1984年   55620篇
  1983年   47361篇
  1982年   28544篇
  1981年   25697篇
  1979年   50704篇
  1978年   36173篇
  1977年   30644篇
  1976年   28369篇
  1975年   30403篇
  1974年   36324篇
  1973年   34632篇
  1972年   32668篇
  1971年   30276篇
  1970年   28167篇
  1969年   27185篇
  1968年   24918篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
Pediatric trachyonychia is an acquired nail disease that can cause distress to families. It is a poorly understood disease, and long‐term follow‐up data are lacking. We present an institutional review of 11 children with isolated pediatric trachyonychia followed over time. Children with the diagnosis of pediatric trachyonychia were identified and invited to participate. Pictures were taken on follow‐up and a questionnaire was answered. Exclusion criteria include having another diagnosis at the initial visit that causes nail dystrophy. Eleven patients with the diagnosis of pediatric trachyonychia were available for follow‐up. The mean age of appearance was 2.7 years (range 2–7 yrs) and the average follow‐up was 66 months (range 10–126 mos). Nine patients were treated with potent topical corticosteroids, one used only petrolatum, and one took vitamin supplements. One patient was found to have an additional skin and hair diagnosis of alopecia areata on follow‐up. On follow‐up, 82% noted improvement of the nails, whereas 18% noted no change. A majority of cases of pediatric trachyonychia are isolated and improve with time, regardless of treatment.  相似文献   
94.
95.
Sinus venosus atrial septal defect (SV‐ASD) usually coexists with partial anomalous pulmonary vein connection (PAPVC). It is a difficult diagnosis in transthoracic echocardiography (TTE) due to eccentric position of defects. We present a rare case of atypical anatomical variation in PAPVC, which was never described before. Two right pulmonary veins drained into superior vena cava, which overrode SV‐ASD and interatrial septum, a third pulmonary vein into the right atrium. Complete diagnosis could not be set after TTE, nor transesophageal echocardiography, whereas angio‐CT was finally conclusive. This diagnostic approach allowed the surgical planning.  相似文献   
96.
97.
98.
Bipolar disorder (BD) is a common psychiatric mood disorder affecting more than 1-2% of the general population of different European countries. Unfortunately, there is no objective laboratory-based test to aid BD diagnosis or monitor its progression, and little is known about the molecular basis of BD. Here, we performed a comparative proteomic study to identify differentially expressed plasma proteins in various BD mood states (depressed BD, manic BD, and euthymic BD) relative to healthy controls. A total of 10 euthymic BD, 20 depressed BD, 15 manic BD, and 20 demographically matched healthy control subjects were recruited. Seven high-abundance proteins were immunodepleted in plasma samples from the 4 experimental groups, which were then subjected to proteome-wide expression profiling by two-dimensional electrophoresis and matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight tandem mass spectrometry. Proteomic results were validated by immunoblotting and bioinformatically analyzed using MetaCore. From a total of 32 proteins identified with 1.5-fold changes in expression compared with healthy controls, 16 proteins were perturbed in BD independent of mood state, while 16 proteins were specifically associated with particular BD mood states. Two mood-independent differential proteins, apolipoprotein (Apo) A1 and Apo L1, suggest that BD pathophysiology may be associated with early perturbations in lipid metabolism. Moreover, down-regulation of one mood-dependent protein, carbonic anhydrase 1 (CA-1), suggests it may be involved in the pathophysiology of depressive episodes in BD. Thus, BD pathophysiology may be associated with early perturbations in lipid metabolism that are independent of mood state, while CA-1 may be involved in the pathophysiology of depressive episodes.  相似文献   
99.
100.
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