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   1985篇
  免费   81篇
  国内免费   17篇
耳鼻咽喉   10篇
儿科学   25篇
妇产科学   90篇
基础医学   205篇
口腔科学   18篇
临床医学   167篇
内科学   587篇
皮肤病学   8篇
神经病学   219篇
特种医学   45篇
外科学   353篇
综合类   9篇
预防医学   39篇
眼科学   9篇
药学   154篇
中国医学   1篇
肿瘤学   144篇
  2023年   8篇
  2022年   29篇
  2021年   59篇
  2020年   39篇
  2019年   44篇
  2018年   60篇
  2017年   30篇
  2016年   46篇
  2015年   64篇
  2014年   77篇
  2013年   118篇
  2012年   143篇
  2011年   169篇
  2010年   88篇
  2009年   71篇
  2008年   147篇
  2007年   123篇
  2006年   142篇
  2005年   123篇
  2004年   97篇
  2003年   116篇
  2002年   100篇
  2001年   11篇
  2000年   12篇
  1999年   4篇
  1998年   11篇
  1997年   14篇
  1996年   5篇
  1995年   11篇
  1994年   11篇
  1993年   6篇
  1992年   7篇
  1991年   5篇
  1988年   10篇
  1987年   2篇
  1986年   2篇
  1985年   8篇
  1984年   5篇
  1983年   5篇
  1982年   15篇
  1981年   7篇
  1980年   5篇
  1979年   4篇
  1977年   3篇
  1976年   2篇
  1975年   2篇
  1973年   5篇
  1972年   4篇
  1971年   3篇
  1942年   2篇
排序方式: 共有2083条查询结果,搜索用时 19 毫秒
51.
52.
Purpose

The recent proliferation of minimally invasive lateral lumbar interbody fusion (LLIF) techniques has drawn attention to potential for these techniques to control or correct sagittal misalignment in adult spinal deformity. We systemically reviewed published studies related to LLIF use in adult spinal deformity treatment with emphasis on radiographic assessment of sagittal balance.

Methods

A literature review was conducted to examine studies focusing on sagittal balance restoration in adult degenerative scoliosis with the LLIF approach.

Results

Fourteen publications, 12 retrospective and 2 prospective, reported data regarding lumbar lordosis correction (1,266 levels in 476 patients) but only two measured global sagittal alignment.

Conclusion

LLIF appears to be especially effective when the lumbar lordosis and sagittal balance correction goals are less than 10° and 5 cm, respectively. However, the review demonstrated a lack of consistent reporting on sagittal balance restoration with the MIS LLIF techniques.

  相似文献   
53.
54.
55.
56.
OBJECTIVES: Vascular endothelial growth factor induces nitric oxide-dependent angiogenic effects and participates in the inflammatory response. This cytokine is over-expressed in the myocardium in experimental models of pressure overload and renal mass ablation, and vascular endothelial growth factor is increased in end-stage renal disease. We investigated the relationship between vascular endothelial growth factor, left ventricular function (by midwall fractional shortening) and mortality in a prospective cohort study in 228 hemodialysis patients. RESULTS: Serum vascular endothelial growth factor concentration was associated directly with interleukin-6 and tumor necrosis factor-alpha (P < 0.01) and inversely with albumin (P = 0.007) but was independent of the endogenous inhibitor of nitric oxide synthesis, asymmetric dimethylarginine. Vascular endothelial growth factor was inversely related with midwall fractional shortening (P = 0.002) and predicted mortality (P = 0.02). In multivariate analyses testing the involvement of this angiogenic cytokine in left ventricular dysfunction and death, these links remained substantially unmodified after adjustment for Framingham risk factors, risk factors peculiar to end-stage renal disease (Hb, Ca, P) and previous cardiovascular complications. However, these links became weaker and not significant when biomarkers of inflammation and asymmetric dimethylarginine were sequentially introduced into the multivariate models. In crude and adjusted analyses, left ventricular function was lowest in patients who displayed both high vascular endothelial growth factor and high asymmetric dimethylarginine, intermediate in patients with either high vascular endothelial growth factor or high asymmetric dimethylarginine and highest in those with low asymmetric dimethylarginine and low vascular endothelial growth factor (P = 0.001). CONCLUSION: Vascular endothelial growth factor is associated with left ventricular systolic dysfunction and mortality in hemodialysis patients. Vascular endothelial growth factor appears to be in the pathway whereby inflammation and nitric oxide inhibition lead to cardiomyopathy and death in hemodialysis patients.  相似文献   
57.
We investigated whether changes in iron metabolism and the transferrin receptor (TRF-R) expression were involved in the antileukaemic effects of arabinoside cytosine (ara-C). Treatment with 100 n M ara-C for 48 h reduced thymidine uptake and increased the surface expression of the TRF-R on leukaemic blasts derived from 13/16 (81%) patients and on the HL-60 and U-937 cell lines. Whereas intracellular non-haem iron was strongly depleted 24 h after ara-C addition, TRF-R up-regulation and recovery of intracellular non-haem iron concentration occurred together after a longer exposure of the cultured cells to the drug. Since iron is an essential regulator of cell proliferation we have evaluated the effects of the combination between ara-C and the iron chelator desferioxamine (DSF) on the growth of HL-60 and U-937 cells. We found that desferioxamine strongly potentiated the effects of ara-C on leukaemic cell growth inhibition and apoptosis. This is the first report of a positive interaction between ara-C and an iron chelator in terms of antileukaemic effects.  相似文献   
58.
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