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   71篇
  免费   4篇
儿科学   3篇
基础医学   17篇
临床医学   1篇
内科学   16篇
神经病学   4篇
特种医学   3篇
外科学   1篇
预防医学   20篇
药学   6篇
肿瘤学   4篇
  2011年   1篇
  2009年   5篇
  2008年   3篇
  2007年   9篇
  2006年   4篇
  2005年   8篇
  2004年   13篇
  2003年   8篇
  2002年   11篇
  2001年   4篇
  2000年   5篇
  1999年   2篇
  1998年   1篇
  1997年   1篇
排序方式: 共有75条查询结果,搜索用时 15 毫秒
41.
Summary Objectives:The conditions under which research utilization leads to policy impact are an important issue in health promotion. This analysis tests the assumption that utilization is positively associated with policy impact only if both political will (i.e., policy opportunities) and social strategies (in intervention and implementation) are present.Methods:A survey of 719 policymakers involved in four poli-cies was conducted in six European countries. Policy impact (output, i.e., program implementation, and outcome, i.e., effects on behavior) and its proposed determinants were analyzed.Results:Regression analyses reveal limited cross-national differences in research utilization, but show comparably high use in policies with a pathogenic focus. Utilization is associated with impact only if political will is lacking; for outcome, this tends to depend on social strategies. Political will is the strongest determinant of impact.Conclusions:Research utilization is not supporting health promotion policy impact if political will is favorable, but if it is poor; political will itself is the crucial determinant of impact. The study contributes to the research utilization-field by showing that research utilization may partially compensate for lack of, rather than depend on, political will.  相似文献   
42.
43.
Estimation of patient dose from radiopharmaceuticals using voxel models   总被引:1,自引:0,他引:1  
The aim of this study was to demonstrate the advantages of patient dosimetry using voxel models and to present sets of dose estimates for patients of different gender and size. These models offer greater realism with respect to organ shape and topology than the well-established Medical Internal Radiation Dose (MIRD)-type mathematical models. At the National Research Centre for Environment and Health (GSF), specific absorbed fractions have been previously calculated for 4 male and 3 female voxel models, representing different age and stature, for a wide range of source organs. For this study, estimates both for established and new radiopharmaceuticals were performed using biokinetic data from International Commission on Radiological Protection (ICRP). The above calculations allowed for comparison to the MIRD technique in relation to the resulting absorbed organ and effective doses. Furthermore, data sets representing a range of voxel phantoms were investigated. It was found that dose differences among the voxel models can amount up to a factor of 3.  相似文献   
44.
Trends in prevalence of atopic diseases and allergic sensitization in children from Eastern Germany during the 1990s were analysed. The study consisted of three regional cross-sectional surveys of a total of 7,632 children (aged 5-14 yrs) in 1992-1993, 1995-1996, and 1998-1999. Information was gathered on atopic diseases and potential predictors by a parental questionnaire. Allergic sensitization for birch, grass, mite, cat, and cladosporium were assessed by radioallergosorbent test (RAST). After adjustment for age, sex and the study area of the participants, prevalence increased between the first and third survey for hay fever, for asthma and for atopic eczema. The adjusted prevalence of allergic sensitization (RAST > 0.35 kU x L(-1)) showed a decrease, whereas the prevalence of strong sensitization (RAST > or = 17.5 kU x L(-1)) increased significantly, specifically in cohorts born after 1989. Further adjustment for possible determinants of these atopic diseases did not change the trend estimates. A clear increase in the prevalence of atopic diseases, with the exception of hay fever, was observed as well as a shift towards a stronger allergic sensitization, which might affect the onset of clinical manifestations of atopic diseases. Differences in the epidemiology of respiratory symptoms, illnesses and allergies between populations living in the former East Germany and those living in the former West Germany have been reported. Among East German children, lower prevalence rates of asthma, and positive skin-prick tests were observed compared to West German children in the early 1990s. Similarly, among East German adults, lower specific immunoglobulin (Ig) E levels and lower prevalence rates of asthma, wheezing, positive methacholine-challenge tests, allergic rhinitis, and positive skin-prick tests have been reported compared to those of West German adults.  相似文献   
45.
46.
We have previously developed two monoclonal antibodies against the Epstein-Barr Virus (EBV) nuclear antigen 1 (EBNA1), designated 1H4 and 2B4. Both detect EBNA1 by in situ staining in established EBV-positive tumours, e.g. Hodgkin's lymphoma and nasopharyngeal carcinoma. An association of EBV with other tumours, notably breast carcinomas, has been reported but remains controversial. Using the antibody 2B4, a nuclear protein has been detected in breast carcinomas that were EBV-negative by other methods, suggesting cross-reactivity with a cellular protein. Furthermore, an association of EBV with various other carcinomas has been reported on the basis of 2B4 immunohistochemistry. Here we show that 2B4 also binds to MAGE-4, a cancer testis antigen expressed in a variety of tumour cells, including breast carcinoma, seminoma and EBV-negative cases of Hodgkin's lymphoma. We conclude that the 2B4 antibody is not suitable for the detection of EBV infection but that additional techniques, particularly in situ hybridization for the detection of the EBV-encoded RNAs (EBERs), should be employed to confirm the presence of EBV. Our results add to the evidence indicating that breast cancer is not an EBV-associated disease.  相似文献   
47.
PM2.5 filter samples were collected in summer 2005 at an urban background site in Augsburg, Germany. They were analyzed for polycyclic aromatic hydrocarbons (PAH) and their oxygenated derivatives (O-PAH) using gas chromatography/mass spectrometry. Oxygen free radical formation (reactive oxygen substances, ROS) was measured by electron spin resonance (ESR) spectroscopy after addition of spin trapping agent directly on the same filters. The concentrations of ambient, high-boiling PAH and O-PAH were highly correlated to ROS formation, even better than to particulate mass or number concentration. Correlations were most pronounced for some polycyclic aromatic monoketones (e.g., benz[de]anthracene-7-one), which are not yet reported in literature to be redox cycling active. The association found between ESR measurements and the presence of specific semivolatile organic compounds suggests an important influence of wood burning in PM2.5-associated ROS formation. These results indicate that further research on the relationship between radical formation and presence of specific O-PAH and semivolatile organic compounds (SVOC) are likely to provide a better understanding of the relationship between the source-dependent chemical composition of PM and the toxicological risks associated with PM exposure.  相似文献   
48.
To investigate trends in the sex odds before and after the Chernobyl accident, gender-specific annual birth statistics were obtained from the Czech Republic, Denmark, Finland, Germany, Hungary, Norway, Poland, and Sweden between 1982 and 1992. For parts of Germany, annual birth statistics and fallout measurements after Chernobyl are available at the district level. Trend models allowing for discontinuities of the male birth proportions are suggested. Superimposed on a downward trend in male proportions there was a jump in 1987 with a sex odds ratio of 1.0047 (95%-confidence interval: 1.0013–1.0081, p = 0.0061). A positive association of the male proportion in Germany between 1986 and 1991 with radioactive exposure at the district level is reflected by a sex odds ratio of 1.0145 per mSv/a (1.0021–1.0271, p = 0.0218). These findings suggest a possible long-term chronic influence of the Chernobyl Nuclear Power Plant accident on the human sex odds at birth in several European countries.  相似文献   
49.
50.
Progressive growth of malignant tumours, metastatic spread and local recurrence after treatment can only be explained by the presence of cells with unlimited proliferative ability. While this is generally accepted, the proportion of such cells and their organization in a hierarchical system of stem cells and non-stem cell progeny is still a matter of controversy. Results of quantitative transplantation and dose requirement of curative radiotherapy have indicated low stem cell fractions in human and early passage rodent tumours, but uncertainty is introduced by uncontrollable experimental or biological factors and the probabilistic nature of stem cell performance itself. Studies using a particular mouse carcinoma (AT17) have given direct insight into the number and clonal expansion of stem cells in situ, strongly supporting the hierarchical concept. The implications are important and concern the relevance of predictive assays, possible mechanisms of accelerated repopulation, or the role of adjuvant treatment strategies.  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