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   2127篇
  免费   101篇
  国内免费   13篇
耳鼻咽喉   12篇
儿科学   100篇
妇产科学   109篇
基础医学   181篇
口腔科学   44篇
临床医学   209篇
内科学   429篇
皮肤病学   53篇
神经病学   46篇
特种医学   316篇
外科学   218篇
综合类   140篇
预防医学   128篇
眼科学   11篇
药学   117篇
  1篇
中国医学   74篇
肿瘤学   53篇
  2021年   26篇
  2020年   15篇
  2018年   23篇
  2017年   26篇
  2016年   26篇
  2015年   47篇
  2014年   56篇
  2013年   57篇
  2012年   70篇
  2011年   77篇
  2010年   71篇
  2009年   69篇
  2008年   71篇
  2007年   66篇
  2006年   61篇
  2005年   46篇
  2004年   42篇
  2003年   40篇
  2002年   33篇
  2001年   37篇
  2000年   19篇
  1999年   33篇
  1998年   48篇
  1997年   63篇
  1996年   54篇
  1995年   46篇
  1994年   58篇
  1993年   38篇
  1992年   23篇
  1991年   19篇
  1990年   27篇
  1989年   32篇
  1988年   32篇
  1987年   32篇
  1986年   32篇
  1985年   19篇
  1984年   20篇
  1983年   17篇
  1982年   14篇
  1981年   23篇
  1980年   22篇
  1968年   12篇
  1959年   40篇
  1958年   64篇
  1957年   87篇
  1956年   47篇
  1955年   77篇
  1954年   69篇
  1953年   18篇
  1952年   15篇
排序方式: 共有2241条查询结果,搜索用时 17 毫秒
1.
2.
Abstract: This paper dicusses the use of esophageal dilatation with a Rigiflex TTS balloon. This method was used 45 times on 11 patients affected by anastomotic or a severe grade peptic esophageal stenosis. Fluoroscopic guidance was used in 36 procedures (80%) without effecting the mean duration of the treatment (12 minutes). The results were considered satisfactory when these goals had been achieved: a) dilatation of the stenosis over 15 mm; b) a dysphagia free-time of more than 6 months. A satisfactory result was achieved in 10 patients (90.9%), without deaths and major complications. 5 patients received 1 dilatation and the other 5 needed, 3-3-4-7–11 procedures respectively to obtain a satisfactory result. On these basis we consider that its great efficacy, security and tolerability depend on the following characteristics of the Rigiflex TTS balloon: 1) “radial” dilatation; 2) the possibility of introducing the balloon through the operative channel of the fiberscope; 3) direct visualization of the stenosis during dilatation. The following disadvantages with this method are: the absence of a tactile sensation of dilatation and the elevated cost of the instrument. We conclude that the Rigiflex TTS balloon is an important alternative to guide-wire techniques, especially for the treatment of severe esophageal strictures.  相似文献   
3.
4.
Anulus fibrosus in bulging intervertebral disks   总被引:1,自引:0,他引:1  
Yu  SW; Haughton  VM; Sether  LA; Wagner  M 《Radiology》1988,169(3):761-763
In this investigation the association of radial tears of the anulus fibrosus and bulging of the intervertebral disk was studied. An index of disk bulging was measured in sagittal anatomic sections in 149 lumbar disks from 31 cadavers. The indexes of disk bulging were correlated with stages of disk development and the presence of an annular tear. The largest disk-bulging indexes were always associated with radial tears of the anulus. Eighty-four percent of the disks with radial tears had disk-bulging indexes greater than 2.5 mm. Most normal adult disks had an index of less than 2.5 mm. The results challenge the concept that the anulus fibrosus is intact in bulging disks, although ruptured in herniated disks.  相似文献   
5.
6.
This retrospective analysis of data collected by the Workers’ Compensation Board for Precision Mechanics and Electrical Engineering of Braunschweig on 42 patients (39 male, 3 female, average age 44 years) seen between 2004 and 2006 with unilateral, isolated calcaneal fractures sustained during work-related accidents and followed from the initial incident report until the first assessment of whether a pension might be justified. The median height of the falla involved was under 2 m. In 27 patients with displaced fractures operative treatment was performed, and in 17 patients the treatment was conservative. The median duration of treatment was 7.5 months. At the time of the first assessment for a pension movement in the upper ankle joint was restricted by an average of 40% and that in the talo-calcaneal joint by 50% compared with the contralateral side. The decrease in earning capacity averaged 19%. The average total cost of treatment per case up to this point was 25,540.-- euros, 61% of which was accounted for by orthotics, rehabilitation and social insurance contributions, 24% by in-patient treatment and 14% by out-patient treatment. Thus, treatment outcomes following calcaneal fractures are still unsatisfactory, resulting in extended absence from work, high costs and high rates of unfitness for work. Immediately after this diagnosis a case manager should be assigned to the patient in an attempt to improve outcomes.  相似文献   
7.
8.
Policosanol is a new cholesterol-lowering drug isolated and purified from sugar-cane wax. which prevents the development of lipofundin-induced lesions and foam-cell formation in New Zealand rabbits and Wistar rats. This study was conducted to examine the effects of policosanol on foam-cell formation in carrageenan-induced granulomas in rats. Eighteen Wistar rats were randomly distributed in three experimental groups which received orally for 20 days Tween 20 H2O as vehicle (control group) or policosanol at 2.5 or 25 mg kg?1. At the 11th day. lipofundin was injected intrapcritoneally for 8 days to induce formation of foam cells in the granuloma. At day 13, carrageenan was injected subcutaneously for granuloma induction and seven days later animals were killed. A significant reduction of the foam-cell formation in granulomas of policosanol-treated rats was observed. It is concluded that policosanol prevents the development of foam cells in carrageenan-induced granulomas (extravascular medium) in rats.  相似文献   
9.
Twelve Sardinian patients affected by histologically defined classic Kaposi's sarcoma (KS) were HLA-A, B, C and DR typed. Compared to 220 age and ethnically matched healthy controls, KS patients showed a significant increase in HLA-DR5 (66.6 vs 23.1%, P less than 0.001) and a considerable decrease in HLA-DR3 (8.3 vs 53.6%, P = 0.0055). No definite association was observed for other HLA antigens. These results confirm the existence of an HLA associated genetic control of KS susceptibility and support the hypothesis that HLA-DR5 plays the role of a predisposition marker while HLA-DR3 bears a genetic resistance to the disease.  相似文献   
10.
Psoriasis is a multifactorial skin disease characterised by epidermal abnormalities and infiltration by lymphocytes and polymorphonuclear leukocytes (PMN). Skin-derived antileukoproteinase (SKALP), also known as elafin, is a potent inhibitor of human leukocyte elastase and proteinase 3, two PMN-derived proteinases implicated in tissue destruction and leukocyte migration. We have shown that, at least at the protein level, SKALP is significantly decreased in lesional skin of patients with pustular psoriasis compared with plaque-type psoriasis. This finding raised the possibility that SKALP could be one of the candidate genes for pustular forms of psoriasis. We therefore performed single strand conformation polymorphism (SSCP) analysis on the SKALP gene to screen for mutations/polymorphisms in the exons of 30 patients with plaque-type psoriasis, 15 patients with pustular psoriasis and 48 healthy controls. In exon 1 a polymorphism was detected at position + 43 relative to the translation start site, resulting in a substitution of threonine for alanine in the signal peptide. In the promoter region a dinucleotide repeat polymorphism was identified. Both polymorphisms were not associated with pustular psoriasis, or psoriasis in general. Our data indicate that the decrease in SKALP activity in pustular psoriasis is not caused by mutations in the coding region of the gene, and that there is no allelic association between pustular psoriasis and SKALP gene polymorphisms.  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