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   3454899篇
  免费   248127篇
  国内免费   9387篇
耳鼻咽喉   48827篇
儿科学   112432篇
妇产科学   97988篇
基础医学   486060篇
口腔科学   98383篇
临床医学   311442篇
内科学   674442篇
皮肤病学   82494篇
神经病学   283137篇
特种医学   133873篇
外国民族医学   1122篇
外科学   520353篇
综合类   72888篇
现状与发展   11篇
一般理论   1322篇
预防医学   258978篇
眼科学   79812篇
药学   254612篇
  12篇
中国医学   7177篇
肿瘤学   187048篇
  2018年   36721篇
  2017年   28571篇
  2016年   32926篇
  2015年   36784篇
  2014年   50805篇
  2013年   76955篇
  2012年   101491篇
  2011年   107672篇
  2010年   64785篇
  2009年   61768篇
  2008年   101259篇
  2007年   108390篇
  2006年   109751篇
  2005年   105551篇
  2004年   101947篇
  2003年   98833篇
  2002年   95683篇
  2001年   161510篇
  2000年   165787篇
  1999年   140028篇
  1998年   40363篇
  1997年   36010篇
  1996年   35598篇
  1995年   34332篇
  1994年   31662篇
  1993年   29712篇
  1992年   109179篇
  1991年   105402篇
  1990年   102418篇
  1989年   99366篇
  1988年   91636篇
  1987年   89895篇
  1986年   84916篇
  1985年   81202篇
  1984年   60921篇
  1983年   51745篇
  1982年   31027篇
  1981年   27816篇
  1979年   55355篇
  1978年   39337篇
  1977年   33928篇
  1976年   31124篇
  1975年   34102篇
  1974年   40180篇
  1973年   38585篇
  1972年   36417篇
  1971年   33993篇
  1970年   31706篇
  1969年   30589篇
  1968年   28397篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
94.
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   
95.
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   
96.
97.
98.
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   
99.
100.
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