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   3251156篇
  免费   231076篇
  国内免费   8422篇
耳鼻咽喉   44796篇
儿科学   107881篇
妇产科学   90271篇
基础医学   458215篇
口腔科学   89578篇
临床医学   295946篇
内科学   632726篇
皮肤病学   78035篇
神经病学   263497篇
特种医学   125658篇
外国民族医学   918篇
外科学   485925篇
综合类   65412篇
现状与发展   6篇
一般理论   1176篇
预防医学   245674篇
眼科学   73672篇
药学   243316篇
  13篇
中国医学   7089篇
肿瘤学   180850篇
  2019年   25493篇
  2018年   36026篇
  2017年   27889篇
  2016年   32222篇
  2015年   36164篇
  2014年   49640篇
  2013年   74252篇
  2012年   99055篇
  2011年   104726篇
  2010年   63012篇
  2009年   60179篇
  2008年   97605篇
  2007年   103852篇
  2006年   105708篇
  2005年   101333篇
  2004年   97361篇
  2003年   93919篇
  2002年   90687篇
  2001年   159354篇
  2000年   163407篇
  1999年   137517篇
  1998年   38866篇
  1997年   34497篇
  1996年   34689篇
  1995年   33515篇
  1994年   30535篇
  1993年   28642篇
  1992年   106380篇
  1991年   102421篇
  1990年   99595篇
  1989年   96348篇
  1988年   88011篇
  1987年   86001篇
  1986年   80896篇
  1985年   76976篇
  1984年   57117篇
  1983年   48135篇
  1982年   28292篇
  1981年   25075篇
  1979年   50567篇
  1978年   35266篇
  1977年   30598篇
  1976年   27780篇
  1975年   30127篇
  1974年   35368篇
  1973年   33750篇
  1972年   31868篇
  1971年   29628篇
  1970年   27245篇
  1969年   26232篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
94.
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   
95.
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   
96.
97.
98.
99.
100.
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