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   29315篇
  免费   849篇
  国内免费   266篇
耳鼻咽喉   264篇
儿科学   607篇
妇产科学   437篇
基础医学   4773篇
口腔科学   355篇
临床医学   2165篇
内科学   5278篇
皮肤病学   319篇
神经病学   2560篇
特种医学   1301篇
外科学   3821篇
综合类   1870篇
一般理论   32篇
预防医学   1792篇
眼科学   331篇
药学   2379篇
  28篇
中国医学   109篇
肿瘤学   2009篇
  2023年   203篇
  2022年   602篇
  2021年   1186篇
  2020年   681篇
  2019年   1038篇
  2018年   1652篇
  2017年   1075篇
  2016年   1543篇
  2015年   1720篇
  2014年   1929篇
  2013年   2462篇
  2012年   2325篇
  2011年   1641篇
  2010年   1830篇
  2009年   1464篇
  2008年   1329篇
  2007年   1288篇
  2006年   1133篇
  2005年   983篇
  2004年   804篇
  2003年   488篇
  2002年   381篇
  2001年   143篇
  2000年   201篇
  1999年   206篇
  1998年   221篇
  1997年   185篇
  1996年   131篇
  1995年   81篇
  1994年   68篇
  1993年   90篇
  1992年   65篇
  1991年   65篇
  1990年   63篇
  1989年   65篇
  1988年   65篇
  1987年   50篇
  1986年   41篇
  1985年   30篇
  1984年   38篇
  1982年   41篇
  1980年   30篇
  1971年   20篇
  1970年   19篇
  1968年   33篇
  1957年   20篇
  1948年   22篇
  1947年   24篇
  1946年   20篇
  1930年   22篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
There is a growing body of evidence that the cytokine, tumor necrosis factor-α (TNF-ga), plays an important role in the development of hepatic ischemia/reperfusion injury. We found that the immunosuppressants, cyclosporine-A (CsA), azathioprine, and FK506, have protective effects on such injury. The purpose of the present study was to elucidate mechanisms involved in these beneficial effects of the immunosuppressant, CsA, on liver injury following cold preservation and transplantation, with special reference to the suppression of TNF-α release. Rat livers were stored in Euro-Collins solution (EC) at 4°C for 6h and orthotopically transplanted. The animals allotted to two groups: group A (untreated controls) and group B (CsA pretreatment of recipients). CsA (10 mg/kg, p.o.) was given for 3 consecutive days preoperatively. CsA pretreatment of the recipients significantly improved the 2-week survival rate (0/6 for group A, 3/6 for group B;P<0.05) and this was associated with a significant decrease in serum TNF-α levels 2h posttransplantation (group A, 69.8±15.7 pg/ml; group B, 22.8±6.8; mean±SEM;n=12 each;P<0.05) and amelioration of sinusoidal endothelial injury, assessed by electron microscopy. Plasma endotoxin levels following reperfusion of the grafts were not altered by the CsA therapy. Morphologically, CsA pretreatment of the recipients did not alter activation of Kupffer cells. CsA pretreatment of the recipient aids in preventing cold preservation/reperfusion injury of the liver graft, possibly by modulating effects of TNF-α.  相似文献   
22.
The capacity of blood pressure cuffs to act as vehicles of hospital infection has been recognised. We describe the microbial flora of in-use DINAMAP blood pressure cuffs used in the operating theatres and one recovery room in a teaching hospital. Our results show significant microbial contamination of in-use blood pressure cuffs.  相似文献   
23.
We describe the clinical and pathological findings of the hemolytic uremic syndrome (HUS) in two children with human immunodeficiency virus (HIV) infection. Both patients presented with microangiopathic hemolytic anemia, thrombocytopenia, and subsequently developed renal failure. The diagnosis of HUS was confirmed by renal histopathology in both patients. None of these children presented with bloody diarrhea, evidence of circulating antibody response to Escherichia coli O157 lipopolysaccharide, or other known risk factors for HUS, except for the presence of HIV infection. Each patient was treated with intravenous plasma infusion and renal replacement therapy. Their clinical course was characterized by non-oliguria and lack of significant hypertension throughout the acute phase of the disease. Despite these favorable clinical parameters, both patients developed end-stage renal failure. The etiology of this atypical HUS characterized by poor renal survival remains unknown and the role of HIV infection in its pathogenesis, although possible, is unclear. Received March 5, 1996; received in revised form and accepted October 15, 1996  相似文献   
24.
25.
26.
The reproductive toxicity of the complex plant preparation Rumalaya was studied in experiments on white mongrel rats. Rumalaya at doses of 400 and 2000 mg/kg given via the intragastric route with simultaneous application of cream to the skin was found to have no embryotoxic or teratogenic actions and had no significant effect on the postnatal development of offspring or the generative functions of female or male rats. Thus, these data identified no contraindications to the clinical use of this agent in pregnant women. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 41, No. 8, pp. 3–6, August, 2007.  相似文献   
27.
Healing of a tendon graft to a bone tunnel is slower than the healing of a bone plug. Therefore, the device chosen for hamstring fixation may need to maintain its strength and stiffness longer than the device chosen for bone-tendon-bone fixation. We evaluated, in an extraarticular ovine model, how 4 and 12 weeks of implantation affect the strength of a tendon graft fixed to bone with the Evolgate. The long digital extensor tendon was transplanted and fixed with the Evolgate into a 30-mm long, 8 mm diameter bone tunnel drilled in the tibial metaphysis of both posterior limbs of 15 skeletally mature Suffolk sheep. Immediately after implantation, and 4 and 12 weeks later, biomechanical cyclic load tests in 50 N increments were performed until failure to evaluate the ultimate failure load (UFL). Histological analysis was also performed at 4 and 12 weeks. Biomechanical tests revealed a UFL of 339±120 N at time 0, and increases to 635±19 N (4 weeks) and to 867±80 N (12 weeks). The differences between all 3 groups were significant (p<0.001, paired t test). The histological evaluation showed a layer of cellular, fibrous tissue between the tendon and the bone, along the length of the bone tunnel; this layer progressively matured and reorganized during the healing process. The collagen fibers that attached the tendon to the bone resembled Sharpey’s fibers. The strength of the interface significantly and progressively increased between weeks 4 and 12 after transplantation, and was associated with a degree of bone ingrowth noted histologically. The use of the Evolgate seems not to interfere with the bone ingrowth after implantation, allowing an improvement in strength of the bonetendon- device complex.  相似文献   
28.
A systematic search was performed to identify outbreaks of methicillin-resistant Staphylococcus aureus infection and colonization caused by healthcare workers (HCWs). Of 191 outbreaks identified, 11 had strong epidemiological evidence that HCWs were the source. In 3 of these outbreaks, asymptomatic carriers were the cause. The frequent practice of screening asymptomatic HCWs should be reconsidered.  相似文献   
29.
30.
The optimum extraction conditions for obtaining a new mixed plant preparation (tanton) have been determined and its phytochemical composition has been studied. The antistressor activity of tanton has been established in experiments on white rats. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 41, No. 11, pp. 42–46, November, 2007.  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