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   1897篇
  免费   112篇
  国内免费   14篇
耳鼻咽喉   72篇
儿科学   99篇
妇产科学   25篇
基础医学   233篇
口腔科学   34篇
临床医学   188篇
内科学   445篇
皮肤病学   30篇
神经病学   89篇
特种医学   321篇
外科学   179篇
综合类   20篇
预防医学   86篇
眼科学   11篇
药学   80篇
中国医学   1篇
肿瘤学   110篇
  2022年   10篇
  2021年   37篇
  2020年   11篇
  2019年   20篇
  2018年   26篇
  2017年   12篇
  2016年   20篇
  2015年   38篇
  2014年   43篇
  2013年   53篇
  2012年   56篇
  2011年   66篇
  2010年   56篇
  2009年   51篇
  2008年   70篇
  2007年   72篇
  2006年   62篇
  2005年   60篇
  2004年   72篇
  2003年   41篇
  2002年   43篇
  2001年   35篇
  2000年   36篇
  1999年   54篇
  1998年   105篇
  1997年   77篇
  1996年   79篇
  1995年   57篇
  1994年   59篇
  1993年   68篇
  1992年   36篇
  1991年   19篇
  1990年   22篇
  1989年   43篇
  1988年   27篇
  1987年   48篇
  1986年   29篇
  1985年   37篇
  1984年   29篇
  1983年   21篇
  1982年   28篇
  1981年   25篇
  1980年   30篇
  1979年   12篇
  1978年   18篇
  1977年   24篇
  1976年   24篇
  1975年   14篇
  1974年   6篇
  1972年   8篇
排序方式: 共有2023条查询结果,搜索用时 15 毫秒
101.
It is imperative to know the details of the anatomy of the nose before understanding any surgical procedure performed on the nose. The details presented in this article should help the experienced and the novice surgeon accomplish the difficult task of a rhinoplasty.  相似文献   
102.

Introduction

The absence of opacities on CT scan usually eliminates paranasal sinus disease as a cause of facial pain. The authors report a case, which constitutes an exception to this general rule, corresponding to a new aetiology of sinus pain.

Case report

A 16-year-old boy presented with very painful “recurrent acute sinusitis” triggered by pressure changes (altitude, diving, surfing), with no sinus opacity on CT scan. Surgical exploration demonstrated absence of a primary or accessory maxillary ostium. Middle meatus antrostomy relieved the patient's pain.

Discussion

The pathophysiology of this case of recurrent acute pseudo-sinusitis and the efficacy of antrostomy can be explained by the evo-devo theory of the origin and function of the paranasal sinuses. This case illustrates the absence of communication in the ethmoid of the membranous sac lining the maxillary sinus, formed by degeneration of the maxillary erythropoietic bone marrow. Under stable environmental conditions, the continuous production of nitric oxide by the sinus epithelium is eliminated by simple transmembrane diffusion, but is insufficiently eliminated in the case of rapid pressure changes, inducing sometimes very severe sinus pain, mimicking sinusitis. This case report paves the way for more detailed studies on the role of the paranasal sinuses in facial disease and respiratory physiology.  相似文献   
103.
104.
105.
We present the clinical details and HLA typing of 15 Celtic Caucasian patients (four male, 11 female) with Behçet''s syndrome (International Study Group criteria). The males affected were younger than the affected females, and three of these males had severe uveal involvement. Two of the 15 patients had the A2 Bw6 Dr4 haplotype but this did not confer family penetrance. Eight had gastrointestinal involvement: two females required ileostomy, two females had chronic diarrhoea, one female had severe ileitis and oesophageal lesions, two males had peptic ulcers, and one female had a peptic ulcer and primary biliary cirrhosis. All of those who developed gastrointestinal symptoms had either the Dr4 or the Dr7 antigens. This study is the largest HLA survey of Celtic Caucasians with Behçet''s syndrome. The clinical features and HLA haplotypes are markedly different from ''Arab'' and ''Japanese'' varieties of Behçet''s syndrome. The expression of the Dr4 and Dr7 antigens in those with gastrointestinal involvement possibly implicates class II antigens (Dr) in the pathogenesis of the manifestations of Behçet''s disease in the bowel.  相似文献   
106.
107.
108.
1. 5-Hydroxytryptamine (5-HT) exerts both contractile and relaxant effects in the marmoset isolated aorta, actions that are unaffected by the 5-HT2 antagonist ketanserin. The aim of the present study was to define the receptors mediating the contractile activity of 5-HT in the marmoset aorta.
2. Contractile responses were elicited in aortic rings that were either: (i) precontracted submaximally with the thromboxane A2 agonist U44069 in order to amplify the responses; or (ii) exposed to N ω-nitro- L -arginine (100 μmol/L) plus LY 53857 (0.1 μmol/L; a 5-HT2 receptor antagonist shown previously to inhibit relaxation). The effect of 5-HT on adenosine 3',5'-cyclic monophosphate (cAMP) formation was also investigated.
3. The effects of agonists and antagonists comprised: (i) agonist potencies in the order 5-carboxamidotryptamine > 5-HT > sumatriptan > 8-hydroxy-2-(di- n -propylamino)tetralin; (ii) inhibition of contractile action of 5-HT by the 5-HT1D antagonist GR 127935; (iii) a contractile response to methysergide; (iv) a lack of effect of tropisetron, an antagonist of 5-HT3 and 5-HT4 receptors; and (v) inhibition of forskolin-stimulated cAMP formation by 5-HT (in the presence of LY 53857), indicative of negative coupling to adenylate cyclase.
4. The above effects fulfil the criteria for a 5-HT1-like receptor. In view of the previous finding that this contractile response is insensitive to ketanserin, it is concluded that the contractile effects of 5-HT in the marmoset aorta are mediated exclusively by a 5-HT1-like receptor.  相似文献   
109.
110.
Bridging bronchus: a rare airway anomaly   总被引:1,自引:0,他引:1  
  相似文献   
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