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   2612799篇
  免费   191794篇
  国内免费   7641篇
耳鼻咽喉   34726篇
儿科学   86005篇
妇产科学   72161篇
基础医学   367924篇
口腔科学   70099篇
临床医学   237528篇
内科学   521003篇
皮肤病学   62776篇
神经病学   216588篇
特种医学   101088篇
外国民族医学   736篇
外科学   391535篇
综合类   51023篇
现状与发展   6篇
一般理论   999篇
预防医学   198241篇
眼科学   57036篇
药学   190205篇
  8篇
中国医学   5378篇
肿瘤学   147169篇
  2021年   20803篇
  2019年   21380篇
  2018年   30232篇
  2017年   23236篇
  2016年   26965篇
  2015年   30382篇
  2014年   41643篇
  2013年   62052篇
  2012年   82876篇
  2011年   87187篇
  2010年   52555篇
  2009年   50558篇
  2008年   81325篇
  2007年   86205篇
  2006年   87824篇
  2005年   84062篇
  2004年   80786篇
  2003年   78030篇
  2002年   75174篇
  2001年   128719篇
  2000年   131540篇
  1999年   110781篇
  1998年   31627篇
  1997年   28235篇
  1996年   28469篇
  1995年   27628篇
  1994年   25284篇
  1993年   23622篇
  1992年   85332篇
  1991年   81706篇
  1990年   78912篇
  1989年   76179篇
  1988年   69580篇
  1987年   68094篇
  1986年   63630篇
  1985年   60590篇
  1984年   45039篇
  1983年   38035篇
  1982年   22570篇
  1981年   20106篇
  1979年   38984篇
  1978年   27424篇
  1977年   23212篇
  1976年   21466篇
  1975年   22798篇
  1974年   26765篇
  1973年   25367篇
  1972年   23755篇
  1971年   21954篇
  1970年   20179篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
83.
84.
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   
85.
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   
86.
87.
88.
89.
90.
In the current immunosuppressive therapy era, vessel thrombosis is the most common cause of early graft loss after renal transplantation. The prevalence of IgA anti–β2-glycoprotein I antibodies (IgA-aB2GPI-ab) in patients on dialysis is elevated (>30%), and these antibodies correlate with mortality and cardiovascular morbidity. To evaluate the effect of IgA-aB2GPI-ab in patients with transplants, we followed all patients transplanted from 2000 to 2002 in the Hospital 12 de Octubre prospectively for 10 years. Presence of IgA-aB2GPI-ab in pretransplant serum was examined retrospectively. Of 269 patients, 89 patients were positive for IgA-aB2GPI-ab (33%; group 1), and the remaining patients were negative (67%; group 2). Graft loss at 6 months post-transplant was significantly higher in group 1 (10 of 89 versus 3 of 180 patients in group 2; P=0.002). The most frequent cause of graft loss was thrombosis of the vessels, which was observed only in group 1 (8 of 10 versus 0 of 3 patients in group 2; P=0.04). Multivariate analysis showed that the presence of IgA-aB2GPI-ab was an independent risk factor for early graft loss (P=0.04) and delayed graft function (P=0.04). There were no significant differences regarding patient survival between the two groups. Graft survival was similar in both groups after 6 months. In conclusion, patients with pretransplant IgA-aB2GPI-ab have a high risk of early graft loss caused by thrombosis and a high risk of delayed graft function. Therefore, pretransplant IgA-aB2GPI-ab may have a detrimental effect on early clinical outcomes after renal transplantation.  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