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   1134篇
  免费   45篇
  国内免费   6篇
耳鼻咽喉   5篇
儿科学   27篇
妇产科学   21篇
基础医学   156篇
口腔科学   21篇
临床医学   90篇
内科学   257篇
皮肤病学   24篇
神经病学   75篇
特种医学   85篇
外科学   232篇
综合类   5篇
预防医学   27篇
眼科学   14篇
药学   96篇
肿瘤学   50篇
  2021年   9篇
  2020年   7篇
  2019年   9篇
  2018年   13篇
  2017年   9篇
  2016年   19篇
  2015年   20篇
  2014年   27篇
  2013年   30篇
  2012年   66篇
  2011年   56篇
  2010年   34篇
  2009年   34篇
  2008年   46篇
  2007年   54篇
  2006年   51篇
  2005年   45篇
  2004年   50篇
  2003年   56篇
  2002年   36篇
  2001年   45篇
  2000年   49篇
  1999年   53篇
  1998年   19篇
  1997年   22篇
  1996年   19篇
  1995年   15篇
  1994年   26篇
  1993年   11篇
  1992年   17篇
  1991年   17篇
  1990年   19篇
  1989年   27篇
  1988年   13篇
  1987年   8篇
  1986年   14篇
  1985年   5篇
  1984年   5篇
  1983年   6篇
  1982年   6篇
  1981年   8篇
  1980年   11篇
  1979年   7篇
  1978年   7篇
  1977年   6篇
  1973年   5篇
  1970年   4篇
  1963年   4篇
  1962年   7篇
  1940年   6篇
排序方式: 共有1185条查询结果,搜索用时 15 毫秒
51.
52.
The influence of aortic valve replacement on the incidence of ventricular arrhythmias was studied by 24-hour Holter electrocardiographic monitoring in 45 patients immediately before and 14 ± 7 months after operation. Ventricular arrhythmias were graded according to the Lown criteria. Preoperative left ventricular (LV) ejection fraction (EF) was determined by angiography and postoperative LVEF by gated blood pool scintigraphy. Repetitive ventricular arrhythmias (Lown grade 4A/B) were associated with a reduced LVEF (< 55%) before and after operation. In 24 patients with preoperative normal LVEF (>- 55%) (group A), mean LVEF remained unchanged after operation (72% vs 71 %). Pre- and postoperative ventricular premature complex (VPC) frequency (45 ± 99 vs 39 ± 94 VPC/24 hours and grade (1.3 vs 1.4) were not significantly different. However, in 17 patients with preoperative impaired LVEF (< 55%) (group B, LVEF preoperatively 40 ± 8%) and marked postoperative improvement (> 10%) (LVEF postoperatively 64 ± 7%), mean VPC frequency decreased from 536 to 69 VPCs/24 hours and mean VPC grade was reduced from 3.8 to 1.5. Complex VPCs were found preoperatively in all 17 patients of group B, but in only 5 patients after operation. Four patients had a reduced LVEF preoperatively and it did not improve postoperatively (group C). Postoperative Holter monitoring detected ventricular tachycardia in all 4 patients.This study indicates that repetitive VPCs are infrequent in patients with normal LVEF before and late after aortic valve replacement. In patients with impaired LVEF and complex VPCs preoperatively, the postoperative improvement of LV function is usually accompanied by a reduction of frequent and complex VPCs.  相似文献   
53.
54.
55.
Journal of Neurology - Volume loss in the deep gray matter (DGM) has been reported in patients with multiple sclerosis (MS) already at early stages of the disease and is thought to progress...  相似文献   
56.
57.

Background

Symptoms at suspicion of necrotizing enterocolitis (NEC) are often nonspecific and several biomarkers have been evaluated for their discriminative power to both diagnose and predict the course from NEC suspicion to complicated disease requiring surgical intervention. Thus, we aimed to assess the utility of interleukin-6 (IL-6) to predict surgical intervention in infants suffering from NEC and, furthermore, to discriminate infants with starting NEC or late-onset sepsis (LOS).

Methods

IL-6 serum levels at disease onset were retrospectively analyzed in 24 infants suffering from NEC as well as 16 neonates with LOS.

Results

IL-6 serum levels at disease onset were significantly higher in infants suffering from NEC necessitating surgical intervention in the disease course compared to infants with medical NEC (5000 [785–5000] vs. 370 [78–4716] pg/ml, p?=?0.0008) as well as gram-positive LOS (5000 [785–5000] vs. 84 [12–269] pg/ml, p?=?0.0001). Infants suffering from gram-negative LOS exhibited elevated IL-6 serum levels at disease onset comparable to infants with surgical NEC (5000 [1919–5000] vs. 5000 [785–5000] pg/ml, p?=?1.00).

Conclusion

The proinflammatory cytokine IL-6 appears to be a promising marker to distinguish surgical NEC from medical NEC at the onset of disease but cannot discriminate between surgical NEC and gram-negative LOS.

Level of evidence

II  相似文献   
58.
A noninvasive means to predict the onset and recurrence of lupus nephritis (LN) before overt renal injury is needed to optimize and individualize treatment. Colony-stimulating factor-1 (CSF-1) is expressed by kidney tubules at the onset of LN, increases with disease progression, and spills into the circulation in lupus-prone mice. We tested the hypothesis that amplified expression of CSF-1 detected in the serum or urine correlates with intrarenal CSF-1 expression and histopathology (increased macrophage accumulation, activity indices) and clinical kidney disease activity and predicts the onset and recurrence of nephritis in patients with systemic lupus erythematosus (SLE). We found increased serum or urine CSF-1 levels in patients with cutaneous, serositis, and musculoskeletal disease; however, the increase in CSF-1 levels was far greater in LN. Moreover, an elevation in serum or urine CSF-1 levels correlated with increasing intrarenal CSF-1 expression and histopathology. By longitudinally tracking patients, we found that elevated serum CSF-1 heralded the initial onset of disease, and a rise in serum or urine CSF-1 predicted recurrences of LN before clinical evidence of glomerular dysfunction and conventional serologic measures, even in patients with other manifestations of SLE. These findings indicate that serial monitoring for a rise in serum or urine CSF-1 levels in patients with SLE reflects kidney histopathology and may predict renal disease activity and the onset and recurrence of LN more accurately than conventional laboratory measures.  相似文献   
59.
60.
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