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   5877382篇
  免费   450660篇
  国内免费   16789篇
耳鼻咽喉   85381篇
儿科学   188604篇
妇产科学   159250篇
基础医学   859201篇
口腔科学   170377篇
临床医学   544414篇
内科学   1068166篇
皮肤病学   134977篇
神经病学   483895篇
特种医学   230593篇
外国民族医学   1607篇
外科学   882649篇
综合类   168730篇
现状与发展   23篇
一般理论   3230篇
预防医学   497658篇
眼科学   143857篇
药学   422896篇
  24篇
中国医学   14707篇
肿瘤学   284592篇
  2021年   57511篇
  2019年   59730篇
  2018年   78284篇
  2017年   59705篇
  2016年   66733篇
  2015年   78184篇
  2014年   113329篇
  2013年   179081篇
  2012年   168010篇
  2011年   181419篇
  2010年   139457篇
  2009年   136384篇
  2008年   166591篇
  2007年   180544篇
  2006年   186330篇
  2005年   180964篇
  2004年   180687篇
  2003年   169453篇
  2002年   159357篇
  2001年   231372篇
  2000年   230979篇
  1999年   204502篇
  1998年   81441篇
  1997年   74507篇
  1996年   72350篇
  1995年   67924篇
  1994年   61967篇
  1993年   57336篇
  1992年   155689篇
  1991年   151584篇
  1990年   146650篇
  1989年   142241篇
  1988年   132025篇
  1987年   129984篇
  1986年   123512篇
  1985年   120254篇
  1984年   95511篇
  1983年   83628篇
  1982年   58208篇
  1981年   53534篇
  1979年   88499篇
  1978年   66813篇
  1977年   57618篇
  1976年   54510篇
  1975年   56325篇
  1974年   66097篇
  1973年   63573篇
  1972年   60023篇
  1971年   55930篇
  1970年   52204篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
211.
212.
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   
213.
214.
215.
216.
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   
217.
218.
219.
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   
220.
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