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   834篇
  免费   50篇
  国内免费   9篇
耳鼻咽喉   5篇
儿科学   39篇
妇产科学   5篇
基础医学   96篇
口腔科学   44篇
临床医学   73篇
内科学   173篇
皮肤病学   40篇
神经病学   27篇
特种医学   149篇
外国民族医学   1篇
外科学   64篇
综合类   39篇
预防医学   58篇
眼科学   5篇
药学   47篇
中国医学   1篇
肿瘤学   27篇
  2022年   2篇
  2021年   2篇
  2020年   4篇
  2019年   7篇
  2018年   9篇
  2017年   13篇
  2016年   13篇
  2015年   25篇
  2014年   13篇
  2013年   29篇
  2012年   20篇
  2011年   25篇
  2010年   31篇
  2009年   46篇
  2008年   24篇
  2007年   18篇
  2006年   20篇
  2005年   14篇
  2004年   30篇
  2003年   15篇
  2002年   9篇
  2001年   6篇
  2000年   6篇
  1999年   18篇
  1998年   54篇
  1997年   62篇
  1996年   56篇
  1995年   42篇
  1994年   40篇
  1993年   37篇
  1992年   7篇
  1991年   11篇
  1990年   16篇
  1989年   14篇
  1988年   22篇
  1987年   23篇
  1986年   21篇
  1985年   9篇
  1984年   4篇
  1983年   8篇
  1982年   18篇
  1981年   3篇
  1980年   9篇
  1979年   4篇
  1978年   4篇
  1977年   5篇
  1976年   6篇
  1975年   2篇
  1968年   3篇
  1959年   2篇
排序方式: 共有893条查询结果,搜索用时 15 毫秒
31.
目的探讨敏感性编码技术(SENSE)前瞻性门控螺旋相位对比MR检查序列在儿童与成人先天性心脏病检查的可行性。材料与方法当地伦理委员会批准该项研究,所有  相似文献   
32.
目的采用心脏MR(CMR)前瞻性研究冠状动脉斑块对心肌缺血的预测价值。方法 52例行冠状动脉造影(CA)后评定为可疑冠心病(CAD)的病人进行了CMR和  相似文献   
33.
Sickle cell disease: imaging of cerebrovascular complications   总被引:3,自引:0,他引:3  
Moran  CJ; Siegel  MJ; DeBaun  MR 《Radiology》1998,206(2):311
  相似文献   
34.
小儿淋巴管瘤的MRI诊断   总被引:7,自引:0,他引:7  
目的分析小儿淋巴管瘤的磁共振表现及其病理基础。方法对6例经手术病理证实的、年龄7天至7岁的小儿淋巴管瘤患者的磁共振表现进行回顾性分析。结果淋巴管瘤磁共振表现为T1WI上呈与肌肉相似或稍高的信号,T2WI上高于脂肪信号。5例瘤内可见低信号分隔,1例瘤内见血管流空影,3例见明显包膜,3例边界不清。2例病理诊断为海绵状淋巴管瘤,4例诊断为囊状淋巴管瘤。结论磁共振成像可较好地显示肿瘤的大小、形态及范围,从而指导手术治疗。  相似文献   
35.
Although it is clear that hypertension accelerates the rate of progression of most forms of chronic renal disease, many unanswered questions remain concerning how to optimally preserve kidney function in patients with hypertension and renal insufficiency. The mechanisms by which hypertension accelerates progression of renal disease have been extensively studied in experimental models. Glomerular capillary hypertension, consequent to an increase in systemic blood pressure combined with a reduction in preglomerular resistance and/or an increase in postglomerular resistance, results in increased hydraulic stress to the glomerular capillary wall. This and other mechanisms result in the release of growth-promoting cytokines and soluble mediators of fibrosis that stimulate cellular proliferation and matrix accumulation, ultimately leading to glomerular sclerosis and interstitial fibrosis. Almost without exception, studies in animals demonstrate that blood pressure reduction reduces the rate of progression of experimental renal disease. Angiotensin-converting enzyme inhibitors and, possibly, calcium antagonists may have a therapeutic advantage compared with other antihypertensive drugs in preventing kidney damage. This has been linked to both blood pressure-dependent and -independent actions. However, most experimental studies have failed to reduce blood pressure to a level sufficient to establish the clinical relevance of potential blood pressure-independent effects. Experimental studies comparing various types of antihypertensive drugs in which a mean arterial pressure (MAP) of approximately 92 mm Hg is achieved are necessary to determine whether clinically important differences in the effects of these drugs on the rate of progression of renal disease exist. Clinical experience with high blood pressure and kidney disease in humans suggests that the risk of developing hypertension-associated renal disease is a continuous variable across the entire range of systolic and diastolic blood pressures. Logically, optimal protection of kidney function may therefore be a continuous function of declining systemic blood pressure. Consistent with this view, recent clinical trials suggest that reducing MAP to 92 mm Hg, corresponding to a blood pressure reading of 125/75 mm Hg, provides more optimal stabilization of renal function in patients with nondiabetic proteinuric kidney disease (>1 g/d) compared with more conventional therapy with a blood pressure goal of 140/90 mm Hg (MAP 107 mm Hg). Clinical trials in patients with diabetes mellitus and renal insufficiency also demonstrate the benefits of reducing blood pressure to approximately 95 mm Hg MAP. Dietary salt consumption may be another important variable affecting the rate of progression of renal disease due to both direct, salt-dependent effects on renal growth and the action of decreased salt intake to augment the antihypertensive and antiproteinuric properties of many drugs. The precise role of alterations in dietary salt consumption on progression of renal disease directly as well as on the effectiveness of various antihypertensive drugs has yet to be examined in clinical trials.  相似文献   
36.
37.
38.
39.
Background  Pemphigus foliaceus is an autoimmune blistering skin disease characterized by the production of pathogenic IgG autoantibodies directed against desmoglein 1.
Aim  To determine the prevalence of anti-desmoglein 1 antibodies in healthy subjects and their distribution in the different regions of Tunisia and to better identify endemic areas of pemphigus foliaceus.
Methods  We tested, by enzyme-linked immunoserbent assay, sera of 270 normal subjects recruited from different Tunisian areas and 203 related healthy relatives to 90 Tunisian pemphigus foliaceus patients.
Results  Seventy-six patients (84.4%), 20 healthy controls (7.4%), and 32 relatives (15.76%) had anti-desmoglein 1 antibodies. In southern regions where pemphigus foliaceus is associated with a significant sex ratio imbalance (9 female : 1 male in the south vs. 2.3 : 1 in the north) and a lower mean age of disease onset (33.5 in the south vs. 45 years in the north), a higher prevalence of anti-desmoglein 1 antibodies in healthy controls was observed (9.23% vs. 5.71% in the north). Interestingly, the highest prevalence of anti-desmoglein 1 antibodies in healthy relatives (up to 22%) was observed in the most rural southern localities. More than half anti-desmoglein 1–positive healthy controls were living in rural conditions with farming as occupation, which suggests that this activity may expose the subjects to particular environmental conditions.
Conclusion  These results show that the endemic features of Tunisian pemphigus foliaceus are focused in these southern areas more than in other areas and that both environmental and genetic factors contribute to the disease.

Conflicts of interest


None declared.  相似文献   
40.
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