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   3389582篇
  免费   243452篇
  国内免费   9109篇
耳鼻咽喉   45575篇
儿科学   112380篇
妇产科学   93090篇
基础医学   479572篇
口腔科学   94438篇
临床医学   308547篇
内科学   667481篇
皮肤病学   80692篇
神经病学   279196篇
特种医学   128280篇
外国民族医学   1085篇
外科学   501771篇
综合类   68309篇
现状与发展   5篇
一般理论   1315篇
预防医学   265618篇
眼科学   75816篇
药学   246696篇
  11篇
中国医学   7167篇
肿瘤学   185099篇
  2021年   28213篇
  2019年   29128篇
  2018年   41698篇
  2017年   31328篇
  2016年   35432篇
  2015年   39877篇
  2014年   54094篇
  2013年   81841篇
  2012年   111329篇
  2011年   117425篇
  2010年   69405篇
  2009年   65168篇
  2008年   108192篇
  2007年   114872篇
  2006年   115872篇
  2005年   111508篇
  2004年   107215篇
  2003年   103174篇
  2002年   99157篇
  2001年   155723篇
  2000年   159580篇
  1999年   134772篇
  1998年   38919篇
  1997年   34638篇
  1996年   34560篇
  1995年   33471篇
  1994年   30816篇
  1993年   28723篇
  1992年   105131篇
  1991年   101472篇
  1990年   98643篇
  1989年   95170篇
  1988年   87073篇
  1987年   85798篇
  1986年   80371篇
  1985年   76977篇
  1984年   57452篇
  1983年   48681篇
  1982年   29032篇
  1979年   51216篇
  1978年   36430篇
  1977年   30912篇
  1976年   28791篇
  1975年   30608篇
  1974年   36511篇
  1973年   34824篇
  1972年   32419篇
  1971年   30206篇
  1970年   27903篇
  1969年   26653篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
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   
102.
103.
104.
105.
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   
106.
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   
107.
108.
109.
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   
110.
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