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   2893篇
  免费   249篇
  国内免费   128篇
耳鼻咽喉   12篇
儿科学   103篇
妇产科学   11篇
基础医学   251篇
口腔科学   126篇
临床医学   338篇
内科学   879篇
皮肤病学   45篇
神经病学   135篇
特种医学   229篇
外科学   546篇
综合类   321篇
预防医学   71篇
眼科学   29篇
药学   108篇
中国医学   20篇
肿瘤学   46篇
  2024年   6篇
  2023年   70篇
  2022年   122篇
  2021年   201篇
  2020年   145篇
  2019年   161篇
  2018年   150篇
  2017年   114篇
  2016年   126篇
  2015年   118篇
  2014年   190篇
  2013年   196篇
  2012年   119篇
  2011年   121篇
  2010年   93篇
  2009年   108篇
  2008年   140篇
  2007年   96篇
  2006年   132篇
  2005年   85篇
  2004年   80篇
  2003年   72篇
  2002年   68篇
  2001年   44篇
  2000年   53篇
  1999年   25篇
  1998年   37篇
  1997年   31篇
  1996年   30篇
  1995年   19篇
  1994年   25篇
  1993年   32篇
  1992年   30篇
  1991年   25篇
  1990年   18篇
  1989年   16篇
  1988年   19篇
  1987年   14篇
  1986年   15篇
  1985年   11篇
  1984年   15篇
  1983年   5篇
  1982年   13篇
  1981年   12篇
  1980年   18篇
  1979年   11篇
  1978年   13篇
  1977年   9篇
  1976年   7篇
  1973年   5篇
排序方式: 共有3270条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
BackgroundThe collagen type IV alpha 1 chain (COL4A1) is an essential component of the basement membrane in small vessels. Pathogenic variants in COL4A1 cause perinatal cerebral hemorrhages in an autosomal-dominant fashion. However, little is known about the long-term outcomes of patients with mildly affecting COL4A1 mutations.Case reportWe report a 17-year-old boy, who presented with recurrent intracranial hemorrhages in the periventricular white matter. He had been followed-up as a child with cerebral palsy bearing intracranial calcifications, developmental delay and epilepsy. Screening tests in infancy provided negative results for intrauterine infections. Severe motor and cognitive deficits persisted after admission. Carbazochrome was introduced on day 19 of admission, which appeared to prevent extension and reactivation of cerebral hemorrhages for over 6 months after discharge.ResultsTargeted sequencing of NOTCH3 and TREX1 excluded causal mutations in these genes. The whole-exome sequencing revealed that he carried a de novo mutation in COL4A1 (p.Gly696Ser). An overview of the literature for 345 cases with COL4A1 mutations supported evidence that p.Gly696Ser is associated with the unique phenotype of late-onset hemorrhage among patients with COL4A1-associated cerebral angiopathy.ConclusionsThis case first demonstrates that infants with COL4A1-associated leukoencephalopathy and calcifications have a risk for developing the rupture of small vessels in the cerebral white matter after 10 years of age.  相似文献   
5.
6.
Congenital rubella syndrome (CRS) results from maternal rubella virus infection in early pregnancy. Abnormal neuroimaging findings have been analyzed in a small number of CRS patients in the past; however, their clinical significance has been poorly addressed. Therefore, we have investigated the neuroimaging findings of 31 patients with CRS from previous studies. The most common finding was parenchymal calcification, which was observed in 18 of 31 patients (58.1%). A multivariable logistic regression model showed that it was associated with psychomotor or mental retardation (p = 0.018), suggesting that parenchymal calcification in CRS could be a prognostic factor.  相似文献   
7.
8.
9.
Abstract: The risk of cardiovascular death is high in hemodialysis (HD) patients, and thickening, stiffening and calcification of the arterial wall have been shown as its predictive factors. Activated vitamin D preparations are used for the treatment of secondary hyperparathyroidism in HD patients, but as they increase serum phosphate and calcium concentrations, there is a concern that they promote vascular calcification and, consequently, exacerbate the outcomes. In this article, the effects of vitamin D therapy on survival, cardiac function, arteriosclerosis, immunity, and inflammation are evaluated by reviewing the literature. In HD patients, the risk of death (particularly cardiovascular death) is significantly lower in those treated than in those not treated with vitamin D. Moreover, activated vitamin D improves cardiac function and alleviates cardiac hypertrophy in HD patients. Experimental data in cultured macrophages, vascular smooth muscle cells, and vascular endothelial cells suggest that it has antiatherosclerotic effects. In vivo, the administration of vitamin D improves immune functions and normalizes inflammatory reactions. In HD patients, vascular calcification is related to the dose of calcium carbonate, but its relationship with the administration of vitamin D is not significant. These observations suggest that, contrary to the general concerns, activated vitamin D exerts favorable effects on the cardiovascular system in HD patients as long as it is used in appropriate clinical doses.  相似文献   
10.
Cardiovascular calcification in end-stage renal disease.   总被引:13,自引:1,他引:12  
Cardiovascular diseases are common in patients with end-stage renal disease (ESRD) and cardiovascular morbidity and mortality among dialysis patients are substantially higher than in the general population. The reasons for this high incidence are multiple. They include traditional factors such as hypertension, diabetes, dyslipidaemia, sodium overload, and elevated homocysteine levels as well as disturbances of mineral metabolism, specifically abnormalities in phosphorus and calcium homeostasis. This review will describe the specific cardiovascular complications related to calcifications in ESRD, the implications of the abnormalities of mineral metabolism in its pathogenesis and the current imaging techniques available for the detection of cardiovascular calcifications. Excess of calcium load contributes to the development of cardiac calcifications; therefore, alternative strategies to diminish exogenous calcium load should be considered in patients with ESRD.  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