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   1643篇
  免费   142篇
  国内免费   22篇
耳鼻咽喉   38篇
儿科学   75篇
妇产科学   31篇
基础医学   179篇
口腔科学   71篇
临床医学   223篇
内科学   297篇
皮肤病学   16篇
神经病学   84篇
特种医学   148篇
外科学   182篇
综合类   46篇
一般理论   3篇
预防医学   183篇
眼科学   30篇
药学   99篇
中国医学   1篇
肿瘤学   101篇
  2023年   14篇
  2021年   33篇
  2020年   30篇
  2019年   27篇
  2018年   24篇
  2017年   29篇
  2016年   33篇
  2015年   34篇
  2014年   44篇
  2013年   51篇
  2012年   64篇
  2011年   68篇
  2010年   58篇
  2009年   43篇
  2008年   66篇
  2007年   88篇
  2006年   66篇
  2005年   47篇
  2004年   44篇
  2003年   57篇
  2002年   42篇
  2001年   69篇
  2000年   49篇
  1999年   39篇
  1998年   47篇
  1997年   30篇
  1996年   42篇
  1995年   33篇
  1994年   34篇
  1993年   34篇
  1992年   42篇
  1991年   22篇
  1990年   39篇
  1989年   26篇
  1988年   37篇
  1987年   34篇
  1986年   29篇
  1985年   19篇
  1984年   18篇
  1983年   11篇
  1982年   16篇
  1981年   11篇
  1980年   17篇
  1978年   13篇
  1977年   13篇
  1976年   10篇
  1974年   10篇
  1973年   14篇
  1972年   9篇
  1970年   9篇
排序方式: 共有1807条查询结果,搜索用时 26 毫秒
1.
2.
3.
This article summarises research undertaken since 1993 in the Willcox laboratory at the University of New South Wales, Sydney on the tear film, its interactions with contact lenses, and the use of tears as a source of biomarkers for ocular and non‐ocular diseases. The proteome, lipidome and glycome of tears all contribute to important aspects of the tear film, including its structure, its ability to defend the ocular surface against microbes and to help heal ocular surface injuries. The tear film interacts with contact lenses in vivo and interactions between tears and lenses can affect the biocompatibility of lenses, and may be important in mediating discomfort responses during lens wear. Suggestions are made for follow‐up research.  相似文献   
4.
Objective: To identify behavioural barriers of service provision within general practice that may be impacting the vaccination coverage rates of Aboriginal children in Perth, Western Australia (WA). Methods: A purposive developed survey was distributed to 316 general practices across Perth and three key informant interviews were conducted using a mixed‐methods approach. Results: Of the surveyed participants (n=101), 67.4% were unaware of the low vaccination coverage in Aboriginal children; 64.8% had not received cultural sensitivity training in their workplace and 46.8% reported having inadequate time to follow up overdue child vaccinations. Opportunistic vaccination was not routinely performed by 30.8% of participants. Key themes identified in the interviews were awareness, inclusion and cultural safety. Conclusion: Inadequate awareness of the current rates, in association with a lack of cultural safety training, follow‐up and opportunistic practice, may be preventing greater vaccination uptake in Aboriginal children in Perth. Cultural safety is a critical component of the acceptability and accessibility of services; lack of awareness may restrict the development of strategies designed to equitably address low coverage. Implications: The findings of this study provide an opportunity to raise awareness among clinicians in general practice and inform future strategies to equitably deliver targeted vaccination services to Aboriginal children.  相似文献   
5.
6.
7.
Objectives. We assessed the effects of a worksite multiple-component intervention addressing diet and physical activity on employees’ mean body mass index (BMI) and the percentage of employees who were overweight or obese.Methods. This group-randomized trial (n = 3799) was conducted at 10 worksites in the northeastern United States. Worksites were paired and allocated into intervention and control conditions. Within- and between-groups changes in mean BMIs and in the percentage of overweight or obese employees were examined in a volunteer sample.Results. Within-group mean BMIs decreased by 0.54 kilograms per meter squared (P = .02) and 0.12 kilograms per meter squared (P = .73) at the intervention and control worksites, respectively, resulting in a difference in differences (DID) decrease of 0.42 kilograms per meter squared (P = .33). The within-group percentage of overweight or obese employees decreased by 3.7% (P = .07) at the intervention worksites and increased by 4.9% (P = .1) at the control worksites, resulting in a DID decline of 8.6% (P = .02).Conclusions. Our findings support a worksite population strategy that might eventually reduce the prevalence of overweight and obesity by minimizing environmental exposures to calorically dense foods and increasing exposures to opportunities for energy expenditure within worksite settings.Sixty-eight percent of adults residing in the United States are overweight or obese,1 and these conditions affect more than 1.4 billion adults worldwide.2 Traditional obesity control strategies, which have focused on changing diet and physical activity (PA) behaviors, provide significant individual benefits3 but are considered insufficient to reduce population disease burdens,4,5 for which broad, population-based approaches are needed.6 In addition to individual biology and behaviors, the physical, social, and cultural environment appears to contribute to the upward trend in population estimates of overweight and obesity7,8 by facilitating high-energy, low-nutrient diets and reducing the need to be physically active to perform activities of daily life.9Worksites are feasible self-contained environments with established communication systems in which interventions manipulating the food and PA environment and the social marketing of lifestyle changes can be implemented. Given that 58.4% of the US population aged 16 years or older is employed,10 worksite interventions have the potential to reach large number of adults11 and can foster the participation of employees in project development and sustainability.12–14 Moreover, participatory worksite interventions address workers’ needs, priorities, and interests and allow strategies to be adapted to the realities of individual sites.13 There is also a business case for weight control programs. In comparison with their nonobese counterparts, overweight and obese employees have higher absenteeism rates, have more work limitations, and are less productive.15–18With these issues in mind, the National Heart, Lung, and Blood Institute developed the Obesity Prevention in the Worksite initiative, a population-based approach to promoting behavioral change through environmental interventions that address prevention and control of weight gain.19 Prior to this initiative, worksite trials were either limited scope interventions, targeting a few aspects of the food or PA environment,9,20–23 or broader scope efforts simultaneously targeting risk factors for cardiovascular disease and cancer (e.g., smoking, diet).24–28 In addition, few studies addressed environmental influences related to excessive weight gain.Here we report the results of Images of a Healthy Worksite, one of the studies that is part of the Obesity Prevention in the Worksite initiative; this comprehensive nutrition and PA intervention was designed to promote healthy lifestyles and to stop the shift to the right of the population body mass index (BMI) curve. In this study, worksites were designated to receive an environmental intervention, and employees participated in intervention design. We hypothesized that mean BMIs among employees at the intervention worksites and the percentages of employees who were overweight or obese would not increase over a 2-year period or would increase less than at control worksites.  相似文献   
8.
9.
10.
Pancreatic neuroendocrine neoplasms (panNEN) are a heterogeneous group of tumors with differing pathological, genetic, and clinical features. Based on clinical findings, they may be categorized into functioning and nonfunctioning tumors. Adoption of the 2017 World Health Organization classification system, particularly its differentiation between grade 3, well-differentiated pancreatic neuroendocrine tumors (panNET) and grade 3, poorly-differentiated pancreatic neuroendocrine carcinomas (panNEC) has emphasized the role imaging plays in characterizing these lesions. Endoscopic ultrasound can help obtain biopsy specimen and assess tumor margins and local spread. Enhancement patterns on computed tomography (CT) and magnetic resonance imaging (MRI) may be used to classify panNEN. Contrast enhanced MRI and diffusion-weighted imaging have been reported to be useful for characterization of panNEN and quantifying metastatic burden. Current and emerging radiotracers have broadened the utility of functional imaging in evaluating panNEN. Fluorine-18 fluorodeoxyglucose positron emission tomography (PET)/CT and somatostatin receptor imaging such as Gallium-68 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid–octreotate PET/CT may be useful for improved identification of panNEN in comparison to anatomic modalities. These new techniques can also play a direct role in optimizing the selection of treatment for individuals and predicting tumor response based on somatostatin receptor expression. In addition, emerging methods of radiomics such as texture analysis may be a potential tool for staging and outcome prediction in panNEN, however further investigation is required before clinical implementation.  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