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   250篇
  免费   23篇
  国内免费   8篇
儿科学   32篇
妇产科学   1篇
基础医学   28篇
口腔科学   7篇
临床医学   31篇
内科学   80篇
皮肤病学   1篇
神经病学   4篇
特种医学   41篇
外科学   13篇
综合类   6篇
预防医学   20篇
眼科学   1篇
药学   6篇
肿瘤学   10篇
  2021年   2篇
  2019年   1篇
  2018年   1篇
  2017年   2篇
  2016年   3篇
  2015年   8篇
  2014年   11篇
  2013年   7篇
  2012年   5篇
  2011年   5篇
  2010年   6篇
  2009年   9篇
  2008年   1篇
  2007年   7篇
  2006年   5篇
  2005年   8篇
  2004年   6篇
  2003年   4篇
  2002年   2篇
  2001年   3篇
  2000年   2篇
  1999年   4篇
  1998年   20篇
  1997年   17篇
  1996年   19篇
  1995年   17篇
  1994年   15篇
  1993年   13篇
  1992年   1篇
  1991年   2篇
  1990年   5篇
  1989年   11篇
  1988年   9篇
  1987年   8篇
  1986年   3篇
  1985年   5篇
  1984年   4篇
  1983年   3篇
  1982年   4篇
  1981年   6篇
  1980年   3篇
  1979年   2篇
  1978年   3篇
  1977年   7篇
  1976年   1篇
  1972年   1篇
排序方式: 共有281条查询结果,搜索用时 453 毫秒
81.

Background  

A supervised land cover classification was developed from very high resolution IKONOS satellite data and extensive ground truth sampling of a ca. 10 sq km malaria-endemic lowland in western Kenya. The classification was then applied to an investigation of distribution of larval Anopheles habitats. The hypothesis was that the distribution and abundance of aquatic habitats of larvae of various species of mosquitoes in the genus Anopheles is associated with identifiable landscape features.  相似文献   
82.
83.
The presentation, pattern of acute illness, and incidence of learning difficulties are described in 63 (33 boys, 30 girls) children with salt wasting 21-hydroxylase deficiency, drawn from a cohort study of congenital adrenal hyperplasia in the South West Region of England between 1968 and 1988. Thirty boys presented with a salt losing crisis from birth whereas the other three boys presented between 2 and 14 months of age with failure to thrive and hyponatraemia. Diagnostic uncertainty led to 13 (43%) of 30 girls developing a salt losing crisis. Five girls were misassigned as boys at birth. There were four deaths in the group, two due to salt losing crisis, one to complications of prematurity possibly compounded by 21-hydroxylase deficiency, and one from heart failure probably related to an excess of steroids. Acute admissions were common, especially during the first year of life, with convulsions in 7% of admissions. The 9% incidence of hypoglycaemia was considered to be an underestimate as blood glucose was measured in only 56 (22%) of 254 admissions. No convulsions occurred in the 38 (15%) admissions where the parents had given intramuscular hydrocortisone before bringing the child to hospital. A high incidence of learning difficulties was found among the 59 surviving children (9/30 (30%) boys and 6/29 (21%) girls), and in only two children could any factor other than 21-hydroxylase deficiency be invoked. Analysis of the subgroup with learning difficulties indicated that they were more ill at presentation with a significantly higher incidence of hypoglycaemia, and that growth in the first year was significantly worse. It is concluded that congenital adrenal hyperplasia remains a formidable disorder with an appreciable mortality and morbidity. The high incidence of learning difficulties seen in salt wasting 21-hydroxylase deficiency needs further attention. A prospective study is indicated to examine the effect of neonatal screening on morbidity from congenital adrenal hyperplasia, particularly the intellectual impairment seen in this study.  相似文献   
84.
We investigated the relationship between travel and changes in routine and the sudden infant death syndrome (SIDS) among 485 SIDS cases compared with 1800 randomly selected control infants. There was no increased risk of SIDS with travel. Special events, such as christenings, were not associated with an increased risk of SIDS. However, visits to and by friends or relatives were associated with a significantly reduced risk of SIDS after controlling for potential confounders (odds ratios = 0.70; 95% confidence interval = 0.52, 0.96). These findings may indicate less social support in SIDS cases.  相似文献   
85.
A 13-year-old girl with Turner's syndrome and bleeding from intestinal venous ectasia is reported. The various types of vascular anomaly of the bowel associated with Turner's syndrome are discussed. Awareness of these anomalies may help prevent unnecessary laparotomy in children with this syndrome.  相似文献   
86.
87.
Gender and the sudden infant death syndrome   总被引:1,自引:0,他引:1  
Abstract A nationwide case-control study compared the prevalence and magnitude of risk factors for sudden infant death syndrome (SIDS) in male and female infants. The risk factors of SIDS and their magnitude for males and females are very similar. After adjustment for potential confounders male infants had a 1.42-fold (95% CI = 1.04, 1.94) increased risk of SIDS compared with females. Risk factors identified in most epidemiological studies are not the reason for the increased SIDS mortality seen in male infants.  相似文献   
88.
89.
One component of the Back to Sleep campaign to reduce the risk of sudden infant death syndrome (SIDS) is the recommendation that parents seek medical attention if their infant is unwell. The aim of this study was to investigate of SIDS could in part be explained by sick infants not getting appropriate medical care. Data on symptoms of illness and on acute medical contacts made for infants dying from SIDS (n = 390) within two weeks of their death were compared with those from a randomly selected group of control infants (n = 1592). SIDS cases had more severe illness than controls (odds ratio (OR) = 3.43; 95% confidence interval (CI) = 1.69 to 5.38), and were more likely to have seen a general practitioner (OR = 1.37; 95% CI = 1.09 to 1.73) or attended hospital (OR = 3.43, 95% CI = 1.09 to 1.73). Only 1.3% of all SIDS cases had symptoms suggesting severe illness and had not seen a general practitioner. A lack of medical contacts in the two weeks before death does not contribute to the risk of SIDS.  相似文献   
90.
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