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   2392480篇
  免费   184776篇
  国内免费   4873篇
耳鼻咽喉   33436篇
儿科学   79619篇
妇产科学   69066篇
基础医学   345297篇
口腔科学   66607篇
临床医学   211542篇
内科学   470156篇
皮肤病学   53607篇
神经病学   192035篇
特种医学   92171篇
外国民族医学   793篇
外科学   363244篇
综合类   54070篇
现状与发展   4篇
一般理论   742篇
预防医学   184510篇
眼科学   55084篇
药学   175489篇
  2篇
中国医学   5204篇
肿瘤学   129451篇
  2018年   25226篇
  2017年   19150篇
  2016年   21697篇
  2015年   24591篇
  2014年   34448篇
  2013年   51730篇
  2012年   70438篇
  2011年   75078篇
  2010年   44340篇
  2009年   42037篇
  2008年   70747篇
  2007年   75642篇
  2006年   76651篇
  2005年   74580篇
  2004年   71699篇
  2003年   68777篇
  2002年   67174篇
  2001年   113186篇
  2000年   115912篇
  1999年   97327篇
  1998年   27810篇
  1997年   25054篇
  1996年   25174篇
  1995年   23879篇
  1994年   21980篇
  1993年   20662篇
  1992年   75804篇
  1991年   73480篇
  1990年   71616篇
  1989年   69050篇
  1988年   63751篇
  1987年   62501篇
  1986年   58978篇
  1985年   56296篇
  1984年   42498篇
  1983年   36471篇
  1982年   21952篇
  1981年   19519篇
  1979年   38922篇
  1978年   27562篇
  1977年   23272篇
  1976年   22105篇
  1975年   23593篇
  1974年   28074篇
  1973年   27070篇
  1972年   25575篇
  1971年   23535篇
  1970年   22161篇
  1969年   20979篇
  1968年   19724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.
We report on a child with several café au lait spots in association with a lumbar lipomeningomyelocele as an apparently new association. Cutaneous markers, the identification of which plays a crucial role in the early diagnosis and management of spinal malformations, can accompany occult spinal dysraphism. Herein we report a case of lumbar lipomeningomyelocele associated with an overlying café au lait spot that served as a marker of occult spinal dysraphism. The patient also had segmental café au lait spots on the face, making the association unique.  相似文献   
46.
47.
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   
48.
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   
49.
50.
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   
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