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   4320897篇
  免费   353015篇
  国内免费   14488篇
耳鼻咽喉   59590篇
儿科学   136556篇
妇产科学   114071篇
基础医学   660463篇
口腔科学   121897篇
临床医学   389868篇
内科学   778404篇
皮肤病学   107647篇
神经病学   360815篇
特种医学   172959篇
外国民族医学   686篇
外科学   661554篇
综合类   128265篇
现状与发展   23篇
一般理论   2535篇
预防医学   355372篇
眼科学   101717篇
药学   310305篇
  27篇
中国医学   11867篇
肿瘤学   213779篇
  2021年   55882篇
  2019年   58479篇
  2018年   73294篇
  2017年   56075篇
  2016年   62203篇
  2015年   75610篇
  2014年   110111篇
  2013年   175454篇
  2012年   114930篇
  2011年   118254篇
  2010年   123364篇
  2009年   125877篇
  2008年   105353篇
  2007年   111125篇
  2006年   120971篇
  2005年   115468篇
  2004年   117482篇
  2003年   107514篇
  2002年   97104篇
  2001年   160900篇
  2000年   156621篇
  1999年   144943篇
  1998年   71255篇
  1997年   67469篇
  1996年   65469篇
  1995年   61045篇
  1994年   55010篇
  1993年   51233篇
  1992年   107471篇
  1991年   103089篇
  1990年   99526篇
  1989年   97381篇
  1988年   89953篇
  1987年   88182篇
  1986年   83865篇
  1985年   82502篇
  1984年   68587篇
  1983年   61114篇
  1982年   48647篇
  1981年   45079篇
  1980年   42496篇
  1979年   60240篇
  1978年   47820篇
  1977年   42910篇
  1976年   39440篇
  1975年   39397篇
  1974年   43455篇
  1973年   41882篇
  1972年   39124篇
  1971年   36444篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
201.
202.
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   
203.
204.
205.
206.
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   
207.
208.
209.
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   
210.
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