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   3461108篇
  免费   249748篇
  国内免费   12204篇
耳鼻咽喉   48685篇
儿科学   112003篇
妇产科学   97747篇
基础医学   486202篇
口腔科学   97774篇
临床医学   313421篇
内科学   674631篇
皮肤病学   82018篇
神经病学   282079篇
特种医学   133874篇
外国民族医学   1139篇
外科学   520374篇
综合类   79165篇
现状与发展   16篇
一般理论   1305篇
预防医学   258851篇
眼科学   80154篇
药学   256333篇
  42篇
中国医学   8946篇
肿瘤学   188301篇
  2018年   37401篇
  2017年   29178篇
  2016年   33306篇
  2015年   37940篇
  2014年   52222篇
  2013年   77491篇
  2012年   102581篇
  2011年   108709篇
  2010年   65588篇
  2009年   62624篇
  2008年   101355篇
  2007年   108324篇
  2006年   109789篇
  2005年   105736篇
  2004年   101461篇
  2003年   98347篇
  2002年   95001篇
  2001年   161596篇
  2000年   165727篇
  1999年   140448篇
  1998年   40726篇
  1997年   36446篇
  1996年   35940篇
  1995年   34648篇
  1994年   31940篇
  1993年   29864篇
  1992年   109324篇
  1991年   105541篇
  1990年   102521篇
  1989年   99407篇
  1988年   91691篇
  1987年   89929篇
  1986年   84934篇
  1985年   81150篇
  1984年   60797篇
  1983年   51664篇
  1982年   30957篇
  1981年   27747篇
  1979年   55278篇
  1978年   39262篇
  1977年   33853篇
  1976年   31041篇
  1975年   34029篇
  1974年   40114篇
  1973年   38506篇
  1972年   36380篇
  1971年   33951篇
  1970年   31662篇
  1969年   30546篇
  1968年   28343篇
排序方式: 共有10000条查询结果,搜索用时 218 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