首页 | 官方网站   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   196篇
  免费   21篇
医药卫生   217篇
  2023年   1篇
  2022年   4篇
  2021年   4篇
  2018年   1篇
  2017年   1篇
  2016年   4篇
  2015年   1篇
  2014年   2篇
  2013年   7篇
  2012年   3篇
  2011年   5篇
  2010年   4篇
  2009年   5篇
  2008年   8篇
  2007年   11篇
  2006年   6篇
  2005年   6篇
  2004年   8篇
  2003年   5篇
  2002年   15篇
  2001年   3篇
  2000年   4篇
  1999年   6篇
  1998年   6篇
  1997年   1篇
  1996年   7篇
  1995年   3篇
  1994年   2篇
  1993年   2篇
  1992年   6篇
  1991年   12篇
  1990年   5篇
  1989年   11篇
  1988年   5篇
  1987年   3篇
  1986年   3篇
  1985年   6篇
  1984年   8篇
  1983年   4篇
  1982年   1篇
  1981年   5篇
  1980年   1篇
  1979年   5篇
  1978年   2篇
  1977年   1篇
  1975年   1篇
  1974年   1篇
  1973年   2篇
排序方式: 共有217条查询结果,搜索用时 15 毫秒
1.
Bone mass and body composition in normal women.   总被引:18,自引:0,他引:18  
The interrelationships between measurements of bone mass and total-body bone mineral were examined in a cross-sectional study of normal healthy women aged 17-82 years. In addition we evaluated the relationship between measures of body composition, estimated by four independent techniques, and bone mass in the same population. Considering the group as a whole, bone mass at all sites correlated with each other and with total-body bone mineral (TBBM). Cancellous and cortical sites could predict TBBM equally well. As expected, all measurements of bone mass were significantly lower in postmenopausal women in comparison to premenopausal women. Declines in bone mass were only seen in premenopausal women in the femoral neck and Ward's triangle, not in lumbar spine, radius, or skeleton as a whole. In postmenopausal women bone mass correlated negatively with age and years from menopause equally at all sites. TBBM was significantly related to height and weight in both premenopausal and postmenopausal women. In premenopausal and postmenopausal women TBBM also correlated with fat mass, but TBBM was much better correlated with percentage body fat in premenopausal than postmenopausal women. TBBM was a constant proportion of lean body mass in premenopausal women, but the fraction of lean mass occupied by the skeleton declined with age in postmenopausal women. Correction of TBBM for lean mass did not change the relationship between TBBM and percentage fat in premenopausal women but eliminated the relationship in postmenopausal women. Regional measurements, which are at least partially corrected for body size by dividing mass by area, correlated less well with height and weight and with any index of obesity, especially in postmenopausal women.  相似文献   
2.
Purpose. The objective of this study is to correlate drug release mechanism with measured drug concentration profiles in gel layers of Carbopol® matrices containing mesalamine or benzoic acid. Methods. Release rate experiments with Carbopol® matrices were performed using a rotating disk apparatus. Matrices were frozen and the gel layer in the matrices was sliced using a microtome in a cryostat. Drug concentration profiles were determined by direct measurement of the concentration of the drug in the gel slices. The pH of the slices was measured using microelectrodes, and water content was measured by Karl Fisher titration. Results. The concentration gradient in mesalamine matrices decreased over time and correlated with square root of time release rate kinetics. The concentration profiles of benzoic acid were unchanged over time and correlated with zero order release rate kinetics. Carbopol gel layers were highly hydrated (93–95% water). Gel layers in matrices with mesalamine had a more alkaline microenvironmental pH. This higher pH resulted in increased growth of the thickness of the gel layer and a reduction drug diffusivity in comparison to benzoic acid matrices. Conclusions. The release rate kinetics of mesalamine and benzoic acid correlated to the measured concentration profiles. The shape of the concentration profiles is determined by the rate of growth of the Carbopol® gel layer and drug diffusivity.  相似文献   
3.
The medical component of workers'' compensation programs-now costing over $24 billion annually-and the rest of the nation''s medical care system are linked. They share the same patients and providers. They provide similar benefits and services. And they struggle over who should pay for what. Clearly, health care reform and restructuring will have a major impact on the operation and expenditures of the workers'' compensation system. For a brief period, during the 1994 national health care reform debate, these two systems were part of the same federal policy development and legislative process. With comprehensive health care reform no longer on the horizon, states now are tackling both workers'' compensation and medical system reforms on their own. This paper reviews the major issues federal and state policy makers face as they consider reforms affecting the relationship between workers'' compensation and traditional health insurance. What is the relationship of the workers'' compensation cost crisis to that in general health care? What strategies are being considered by states involved in reforming the medical component of workers compensation? What are the major policy implications of these strategies?  相似文献   
4.
Reverse targeting of preventive care due to lack of health insurance   总被引:13,自引:1,他引:12  
S Woolhandler  D U Himmelstein 《JAMA》1988,259(19):2872-2874
We analyzed patterns of receipt of preventive services among middle-aged women, with particular attention to health insurance coverage, based on data from the National Health Interview Survey. Lack of insurance was most prevalent among socioeconomically disadvantaged women at high risk for disease and was the strongest predictor of failure to receive screening tests. The relative risk of inadequate screening for uninsured compared with insured women was 1.60 (95% confidence interval [Cl], 1.40 to 1.83) for blood pressure checkups, 1.55 (95% Cl, 1.43 to 1.68) for cervical smears, 1.52 (95% Cl, 1.41 to 1.63) for glaucoma testing, and 1.42 (95% Cl, 1.33 to 1.51) for clinical breast examination. Controlling for demographic and health status variables did not diminish the effect of insurance coverage. We conclude that inadequate insurance coverage leads to "reverse targeting" of preventive care--that is, populations at highest risk are least likely to be screened. This compromises both the effectiveness and the cost-effectiveness of screening.  相似文献   
5.
OBJECTIVES. To describe a theoretic approach and rationale for the integration of health protection and health promotion in worksite cancer prevention programs and to describe an intervention study designed to implement this integration. METHODS. Twenty-four worksites were recruited to participate in this randomized, controlled study. The theoretically based intervention model integrates health promotion and health protection through (1) joint worker-management participation in program planning and implementation, (2) consultation on worksite changes, and (3) educational programs targeting health behavior change. RESULTS. Although the primary purpose of this paper is to describe a theoretic approach to the integration of health promotion and health protection, preliminary results are also noted. In these predominantly manufacturing worksites, many workers faced the double jeopardy of exposures to occupational carcinogens and personal risks such as smoking or poor dietary habits. Production workers' job responsibilities frequently limited their full participation. Barriers to participation were identified early in the project, and strategies were developed to facilitate maximal worker involvement and worksite changes. CONCLUSIONS. Lifestyle changes such as smoking cessation or dietary changes may be more effectively promoted among blue collar audiences when programs also encourage management actions to reduce occupational exposures. Public health professionals trained in health promotion and health protection must work together to effectively address the health concerns of this population.  相似文献   
6.
Going bare: trends in health insurance coverage, 1989 through 1996.   总被引:7,自引:5,他引:2       下载免费PDF全文
OBJECTIVES: This study analyzed trends in health insurance coverage in the United States from 1989 through 1996. METHODS: Data from annual cross-sectional surveys by the US Census Bureau were analyzed. RESULTS: Between 1989 and 1996, the number of uninsured persons increased by 8.3 million (90% confidence interval [CI] = 7.7, 8.9 million). In 1996, 41.7 million (90% CI = 40.9, 42.5 million) lacked insurance. From 1989 to 1993, the proportion with Medicaid increased by 3.6 percentage points (90% CI = 3.1, 4.0), while the proportion with private insurance declined by 4.2 percentage points (90% CI = 3.7, 4.7). From 1993 to 1996 private coverage rates stabilized but did not reverse earlier declines. Consequently, the number uninsured continued to increase. The greatest increase in the population of uninsured [corrected] was among young adults aged 18 to 39 years; rates among children also rose steeply after 1992. While Blacks had the largest percentage increase, Hispanics accounted for 36.4% (90% CI = 32.3%, 40.5%) of the increase in the number uninsured. From 1989 to 1993, the majority of the increase was among poor families. Since then, middle-income families have incurred the largest increase. Northcentral and northeastern states had the largest increases in percent uninsured. CONCLUSIONS: Despite economic prosperity, the numbers and rates of the uninsured continued to rise. Principally affected were children and young adults, poor and middle income families, blacks, and Hispanics.  相似文献   
7.
8.
9.
When Seiss-Inquart, Reich Commissar for the Occupied Netherlands Territories, wanted to draw the Dutch physicians into the orbit of activities of the German medical profession, he did not tell them ‘you must send your chronic patients to death factories’ or ‘you must give lethal injections at government request in your offices,’ but he couched his order in most careful and superficially acceptable terms… ‘It is the duty of the doctor, through advice and effort, conscientiously and to his best ability, to assist as helper the person entrusted to his care in the maintenance, improvement and re-establishment of his vitality, physical efficiency and health. The accomplishment of this duty is a public task.’  相似文献   
10.
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-23

京公网安备 11010802026262号