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   582篇
  免费   40篇
儿科学   23篇
妇产科学   23篇
基础医学   33篇
口腔科学   25篇
临床医学   21篇
内科学   208篇
皮肤病学   2篇
神经病学   19篇
特种医学   1篇
外科学   23篇
综合类   4篇
一般理论   1篇
预防医学   199篇
眼科学   16篇
药学   7篇
中国医学   13篇
肿瘤学   4篇
  2023年   8篇
  2022年   13篇
  2021年   27篇
  2020年   22篇
  2019年   28篇
  2018年   22篇
  2017年   16篇
  2016年   26篇
  2015年   31篇
  2014年   31篇
  2013年   70篇
  2012年   23篇
  2011年   34篇
  2010年   25篇
  2009年   30篇
  2008年   24篇
  2007年   23篇
  2006年   23篇
  2005年   16篇
  2004年   22篇
  2003年   11篇
  2002年   18篇
  2001年   15篇
  2000年   9篇
  1999年   7篇
  1998年   8篇
  1997年   8篇
  1996年   7篇
  1995年   5篇
  1994年   1篇
  1993年   1篇
  1992年   4篇
  1991年   3篇
  1990年   1篇
  1989年   1篇
  1988年   2篇
  1986年   2篇
  1985年   1篇
  1984年   2篇
  1980年   1篇
  1978年   1篇
排序方式: 共有622条查询结果,搜索用时 31 毫秒
81.
The POLA study (June 1995 through July 1997) is a population-based study on cataract and age-related macular degeneration (AMD) and their risk factors in 2584 residents of Séte (South of France), aged 60–95 years. Classification of AMD was performed on 50° fundus photographs, according to an international classification. The presence of cardiovascular disease and its risk factors was determined by interviewer-based questionnaire, clinical examination (anthropometry, blood pressure) and fasting plasma measurements. Using a logistic model adjusted for age and gender, late AMD was not significantly associated with a history of cardiovascular disease, diabetes, use of hypocholesterolemic drugs, hypertension, blood pressure or plasma lipids. Obese subjects (body mass index greater than 30 kg/m 2 ) had a 2.29-fold (95% confidence interval (CI): 1.00–5.23) and 1.54-fold (CI: 1.05–2.26) increased risk of late AMD and pigmentary abnormalities in comparison with lean subjects. Finally, the risk of soft drusen was decreased in those subjects with a history of cardiovascular disease (odds-ratio (OR) = 0.72, CI: 0.54–0.97), and increased with increasing levels of HDL-cholesterol (OR = 1.52, CI: 1.14–2.02). None of these results were modified by further adjustments for smoking, educational level and plasma alpha-tocopherol. These results need to be confirmed by other studies, which ideally should be longitudinal and prospective.  相似文献   
82.
Understanding psychosocial, sexual behavior and knowledge differences between never, inconsistent and consistent condom users can improve interventions to increase condom use in resource-poor countries, but they have not been adequately studied. We examined these differences in a cohort of 961 female hotel and bar workers in Moshi, Tanzania. Forty-nine percent of women reported no condom use; 39% reported inconsistent use, and 12% reported consistent use. Women with multiple sexual partners in the past five years were less likely to be consistent rather than inconsistent users as were women who had ever exchanged sex for gifts or money. Inconsistent users had higher condom knowledge and higher perceived acceptability of condom use than did never users, but they did not differ from consistent users by these factors. There are important differences between women by level of condom use. These findings can help inform interventions to increase condom use.  相似文献   
83.
Objective  To describe unsafe abortion methods and associated health consequences in Tanzania, where induced abortion is restricted by law but common and known to account for a disproportionate share of hospital admissions.
Method  Cross-sectional study of women admitted with alleged miscarriage: 278 in rural Tanzania and 473 in urban Tanzania. Women who had undergone a clandestinely induced abortion were identified by an empathetic approach and interviewed in detail about the procedure. Information about complications was obtained from the patient file.
Results  Sixty-two per cent in rural Tanzania and 63% in urban Tanzania stated that they had had an unsafe induced abortion. The abortion had been induced by an unskilled provider in 46% of rural women and 60% of urban women. Herbs and roots had commonly been used for induction, in 42% of rural and 54% of urban women. The method most often associated with abortion complications was catheter/roots, whereas the method least often associated with complications was herbs.
Conclusion  The large number of women identified as having had unsafe abortion together with the prevalent use of herbs calls for attention.  相似文献   
84.
Detecting potential changes in genetic diversity in schistosome populations following chemotherapy with praziquantel (PZQ) is crucial if we are to fully understand the impact of such chemotherapy with respect to the potential emergence of resistance and/or other evolutionary outcomes of interventions. Doing so by implementing effective, and cost-efficient sampling protocols will help to optimise time and financial resources, particularly relevant to a disease such as schistosomiasis currently reliant on a single available drug. Here we explore the effect on measures of parasite genetic diversity of applying various field sampling approaches, both in terms of the number of (human) hosts sampled and the number of transmission stages (miracidia) sampled per host for a Schistosoma mansoni population in Tanzania pre- and post-treatment with PZQ. In addition, we explore population structuring within and between hosts by comparing the estimates of genetic diversity obtained assuming a ‘component population’ approach with those using an ‘infrapopulation’ approach. We found that increasing the number of hosts sampled, rather than the number of miracidia per host, gives more robust estimates of genetic diversity. We also found statistically significant population structuring (using Wright's F-statistics) and significant differences in the measures of genetic diversity depending on the parasite population definition. The relative advantages, disadvantages and, hence, subsequent reliability of these metrics for parasites with complex life-cycles are discussed, both for the specific epidemiological and ecological scenario under study here and for their future application to other areas and schistosome species.  相似文献   
85.

Background

The public health and socio-economic burden of Human African Trypanosomiasis (HAT) in East Africa is not well documented. Understanding the epidemiology and impact of HAT in such settings is difficult due to a lack of robust surveillance and reporting systems, restricting evidence-based policy development and contributing to the continued neglect of this disease.

Objective

To investigate the burden of HAT in Urambo District, Tanzania in order to inform future public health policy.

Methods

A rapid participatory appraisal (RPA) using a combination of qualitative and quantitative methods was conducted, that included key informant interviews, hospital record analysis, and tools adapted from participatory learning and action.

Results

Three villages adjacent to Ugala Game Reserve appeared to be the most affected. High levels of under-reporting were noted due to a lack of diagnostic tools at peripheral health care facilities and limited access to specialist services. Community stakeholders perceived the health and socio-economic burden of HAT to be similar to that of malaria.

Conclusion

The burden of HAT in remote rural communities is difficult to capture through routine surveillance systems alone. The RPA represents an efficient mechanism for engaging communities in public health action for trypanosomiasis control in northwest Tanzania.  相似文献   
86.
87.
In sub-Saharan Africa, female bar workers (FBWs) often serve as informal sex workers. Little is known about the prevalence of HIV and HIV-related risk factors among FBWs in Dar es Salaam (DSM), Tanzania. Using an adapted Structural HIV Determinants Framework, we identified structural, interpersonal, psychosocial, and behavioral risk factors for HIV acquisition. We compared the prevalence of HIV and HIV-related risk factors among a random sample of 66 FBWs from DSM to an age-standardized, representative sample of female DSM-residents from the 2016 Demographic and Health and 2011–2012 AIDS Indicator Surveys. Compared to other women in DSM, FBWs had elevated prevalence of all four groups of risk factors. Key risk factors included gender and economic inequalities (structural); sexual violence and challenges negotiating condom use (interpersonal); depression, post-traumatic stress disorder, and low social support (psychosocial); and history of unprotected sex, multiple sex partners, and high alcohol consumption (behavioral). HIV prevalence did not differ between FBWs (7.1%, 95% CI 3.7-13.3%) and survey respondents (7.7%, 95% CI: 5.3-11.1%), perhaps due to FBWs’ higher – though sub-optimal – engagement with HIV prevention strategies. Elevated exposure to HIV-related risk factors but low HIV prevalence suggests economic, psychosocial, and biomedical interventions may prevent HIV among FBWs in DSM.  相似文献   
88.
The consumption of bottled and plastic-bagged drinking water in Tanzania has increased largely because of the deteriorating quality of tap water. It is uncertain whether these water products are safe for drinking. In this study, the microbiological quality of bottled and plastic-bagged drinking water sold in Dar es Salaam, Tanzania, was investigated. One hundred and thirty samples representing 13 brands of bottled water collected from shops, supermarkets and street vendors were analysed for total coliform and faecal coliform organisms as well as heterotrophic bacteria. These were compared with 61 samples of tap water. Heterotrophic bacteria were detected in 92% of the bottled water samples analysed. Total and faecal coliform bacteria were present in 4.6% and 3.6%, respectively, of samples analysed with a tendency for higher contamination rates in plastic-bagged drinking water. Microbiological quality of tap water was found to be worse compared with bottled water, with 49.2% and 26.2% of sampling points showing the presence of total coliform and faecal coliform organisms, respectively. The results suggest caution and vigilance to avert outbreaks of waterborne diseases from these types of drinking water.  相似文献   
89.
Cholera outbreaks have occurred in Burundi, Rwanda, Democratic Republic of Congo, Tanzania, Uganda, and Kenya almost every year since 1977-1978, when the disease emerged in these countries. We used a multiscale, geographic information system-based approach to assess the link between cholera outbreaks, climate, and environmental variables. We performed time-series analyses and field investigations in the main affected areas. Results showed that cholera greatly increased during El Nino warm events (abnormally warm El Ninos) but decreased or remained stable between these events. Most epidemics occurred in a few hotspots in lakeside areas, where the weekly incidence of cholera varied by season, rainfall, fluctuations of plankton, and fishing activities. During lull periods, persistence of cholera was explained by outbreak dynamics, which suggested a metapopulation pattern, and by endemic foci around the lakes. These links between cholera outbreaks, climate, and lake environments need additional, multidisciplinary study.  相似文献   
90.
Most malaria risk reduction strategies are firmly embedded in biomedical practices and public health perspectives. National and international programmes to 'control' malaria are particularly characterised by the promotion of public health interventions which converge on the disease vector, the malaria mosquito, notably through the use of indoor household spraying with insecticides, and the deployment of insecticide-treated bednets (ITNs). With convincing evidence for the effectiveness of ITNs in reducing the incidence of malaria, control programmes have emphasised the notion of 'scaling-up' bednet coverage. Much previous research on people's 'compliance' with bednet programmes has tended to focus on the quantification of bednet usage and on deriving explanations for 'non-compliance' based on household or individual indicators such as wealth, age, gender or educational level, or on climatic factors such as season and temperature. However, malaria risk behaviours are also rooted in wider aspects of local livelihoods, and socio-cultural beliefs and practices which interplay with the use and, crucially, non-use, of bednets. This paper draws on empirical data derived from in-depth, one-to-one semi-structured interviews, focus groups and participatory methods (mapping and diagramming) with participants in two villages in rural Tanzania to explore the nature of these practices and vulnerabilities, and their potential impact on malaria exposure risk. Participants included farmers and pastoralists, both men and women, as well as village 'officials'. By eliciting local understandings of malaria-related behaviours we explore how malaria risks are played out in people's everyday lives, and the circumstances and decision-making which underpin non-usage of bednets. Our findings reveal the importance of shifting sleeping patterns in response to livelihood needs and socio-cultural practices and events. These arrangements militate against the consistent and sustained use of the bednet which are called for by public health policies. In particular we demonstrate the importance of the spatial and temporal dimensions of farming practices and the role of conflict over access to shared land; the impact of livelihood activities on malaria risks for school-aged children; risk behaviours during 'special' socio-cultural events such as funeral ceremonies; and routine, outdoor activities around dawn and dusk and the gendered nature of these practices.  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