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   53篇
  免费   1篇
妇产科学   15篇
基础医学   4篇
临床医学   3篇
内科学   7篇
皮肤病学   1篇
特种医学   1篇
外科学   5篇
综合类   1篇
预防医学   14篇
中国医学   1篇
肿瘤学   2篇
  2021年   1篇
  2020年   2篇
  2018年   1篇
  2017年   1篇
  2015年   1篇
  2013年   1篇
  2011年   3篇
  2010年   2篇
  2009年   3篇
  2008年   1篇
  2007年   3篇
  2006年   3篇
  2005年   1篇
  2004年   3篇
  2003年   1篇
  2002年   6篇
  2001年   2篇
  2000年   1篇
  1999年   2篇
  1996年   2篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
  1987年   3篇
  1986年   3篇
  1985年   1篇
  1983年   1篇
  1971年   1篇
  1967年   1篇
  1960年   1篇
排序方式: 共有54条查询结果,搜索用时 15 毫秒
41.
42.
Studies on sexual behavior among adolescents are fundamental in understanding and fighting against outcomes of unprotected sex that include unplanned/unwanted pregnancies and sexually transmitted diseases. This survey conducted among in- and out-of-schools adolescents measured prevalence of sexual behavior variables, including risky sexual behavior and associated factors. Risky sexual behavior was defined as having first sex before 16 years, inconsistent condom use and having multiple sexual partners. About 30% of adolescents reported being sexually active; a higher proportion being among males than females and 24.5% of sexually active adolescents reported having multiple sexual partners. More males (37%) reported having multiple sexual partners than females (26%). Nearly 48% of unmarried sexually active adolescents reported having used a condom during the most recent sexual intercourse. Predictors of risky sexual behavior were being male, young age (10–14 years) and being inschool. Preventive information and education should take into consideration these factors.  相似文献   
43.
BACKGROUND: High maternal age is a well-recognized risk factor for Down's syndrome. There are also several studies of a possible effect of paternal age, but no consistent evidence of an association is found. Less is known about any effects of the age of grandparents. Objective. To assess whether maternal or paternal grandparents' age is associated with the risk of Down's syndrome. METHODS: We used logistic regression analyses with data from the Medical Birth Registry of Norway, adjusting for possible confounding factors. RESULTS: We found no evidence of an association with the risk of Down's syndrome either for a maternal grandmother's age (odds ratio 0.9, 95% confidence interval 0.6-1.5 per 10-year increase in grandmother's age) or for any of the other grandparents' age. CONCLUSIONS: High maternal age remains the only well-established age-related risk factor for Down's syndrome. There is little evidence that the increased risk represented by older mothers is passed on to offspring of her non-affected daughters.  相似文献   
44.
Paternal age and the risk of birth defects in Norway   总被引:5,自引:0,他引:5  
PURPOSE: We studied 1,869,388 births from The Medical Birth Registry of Norway to assess the effect of father's age on risks of birth defects in offspring. METHOD: Thirteen separate categories were studied including pooled categories of neural tube defects and any type of defect. We used logistic regression models to adjust for maternal age, year of birth, maternity institution, parity, and correlation between siblings. RESULTS: There was little evidence of increased risk by high paternal age for any category of defects, except for a category of "other central nervous system" where risk estimates were 2.5-fold (95% CI: 1.2-5.5) for fathers aged between 45 and 49 years compared with the reference age group (25-29 years). The risk for neural tube defects was 1.3-fold (95% CI: 1.1-1.5) when the father was aged between 20 and 24 years relative to the reference. A pattern of moderately higher risks for younger fathers was consistent for anencephaly and spina bifida. Increased risk of heart defects was also estimated among children of young fathers. CONCLUSIONS: This study does not show consistent evidence that paternal ageing is a risk for birth defects among offspring. Low paternal age, or factors associated with younger parents, may however be associated with increased risk of neural tube defects in their offspring.  相似文献   
45.
46.
Scanning electron microscopy (SEM) was used to study an IUD from an asymptomatic patient with Actinomyces-like organisms on Papanicolaou smear and in whom Actinomyces israelii was determined to be present in cervical smears. The objective was to determine if there were any variations in surface morphology that might be correlated with the Actinomyces-like organisms. SEM revealed numerous areas of thick surface encrustation. The surface morphology of the IUD fragments showed basic similarities to the morphologies observed in other cases. Encrustations were attached to the arms and stem of the device. A unique finding was apparently biological material adherent to a fragment of encrusted material. Filamentous structures radiated perpendicularly from a central core. These filaments resembled Actinomyces-like organisms in the patient's Pap smear. Also of interest was a delicate network of hair-like structures at the bottom of a naturally occurring space in the surface encrustation.  相似文献   
47.
Suicide surveillance was launched at the Muhimbili National Hospital mortuary in Dar es Salaam Region, Tanzania from 1st January to 31st December, 2005 to determine its magnitude and characteristics. Following the WHO guidelines with minor modifications, information on sex, dates of birth and death, places of residence and death, occupation, reasons and means of suicide were collected. There were 65 (2.3 per 100,000 population) suicides recorded in 2005. The suicide rate for males was 3.4/100,000 and for females was 1.2/100,000 which maybe some of the lowest rates ever reported in the world. The mean age at suicide was 32.9 (SD=13.1) years. Males were about three times more likely to commit suicide as females. The main motive behind suicide was recorded for 26 (40%) victims as family-related and for 11 (17%) as health related. Although there was a wide range of ages at which people committed suicide, the average age seems to be very low. Since reasons for suicide are coated with family problems, strategies to improve awareness of psychological and mental health services and to provide alternative economic and social support networks are advocated.  相似文献   
48.
49.
50.
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