全文获取类型
收费全文 | 7917篇 |
免费 | 865篇 |
国内免费 | 66篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 135篇 |
妇产科学 | 180篇 |
基础医学 | 203篇 |
口腔科学 | 158篇 |
临床医学 | 991篇 |
内科学 | 1107篇 |
皮肤病学 | 23篇 |
神经病学 | 224篇 |
特种医学 | 86篇 |
外科学 | 552篇 |
综合类 | 426篇 |
现状与发展 | 1篇 |
一般理论 | 10篇 |
预防医学 | 3696篇 |
眼科学 | 25篇 |
药学 | 827篇 |
2篇 | |
中国医学 | 49篇 |
肿瘤学 | 134篇 |
出版年
2024年 | 26篇 |
2023年 | 241篇 |
2022年 | 275篇 |
2021年 | 537篇 |
2020年 | 471篇 |
2019年 | 522篇 |
2018年 | 460篇 |
2017年 | 447篇 |
2016年 | 359篇 |
2015年 | 338篇 |
2014年 | 476篇 |
2013年 | 747篇 |
2012年 | 387篇 |
2011年 | 421篇 |
2010年 | 347篇 |
2009年 | 359篇 |
2008年 | 333篇 |
2007年 | 355篇 |
2006年 | 266篇 |
2005年 | 220篇 |
2004年 | 194篇 |
2003年 | 168篇 |
2002年 | 155篇 |
2001年 | 117篇 |
2000年 | 123篇 |
1999年 | 87篇 |
1998年 | 60篇 |
1997年 | 73篇 |
1996年 | 40篇 |
1995年 | 36篇 |
1994年 | 33篇 |
1993年 | 23篇 |
1992年 | 29篇 |
1991年 | 25篇 |
1990年 | 28篇 |
1989年 | 12篇 |
1988年 | 11篇 |
1987年 | 6篇 |
1986年 | 7篇 |
1985年 | 12篇 |
1984年 | 2篇 |
1983年 | 8篇 |
1982年 | 1篇 |
1981年 | 5篇 |
1980年 | 1篇 |
1977年 | 3篇 |
1974年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有8848条查询结果,搜索用时 320 毫秒
61.
To protect plasma supplies, donors are screened for infectiousdiseases. As an added measure of protection, donations are identifiedand stored for a period of time to allow future discard in theevent that an identified donor subsequently tests positive forsome screened disease. Previous models for evaluating such plasmaholds have only addressed the case of a single infectious disease.This paper extends the analysis to the case of multiple infections.Given knowledge of the marginal incidence rates for those infectionschecked, upper and lower bounds for important quantities suchas the probability of interdicting an infectious but undetecteddonation, the expected number of infections interdicted perdonation, and the net economic benefits of the holding policyare developed. Several examples are developed, illustratinghow the models can be used to evaluate the consequences of aplasma hold. 相似文献
62.
【目的】 搭建一个适合我国科技期刊关联数据出版的框架,为科技期刊制订关联数据开放共享及出版政策提供参考。【方法】 通过文献分析和网络调研方法,对国内外出版机构及科技期刊在关联数据出版方面的政策进行跟踪调研,并基于数据FAIR原则,分别从数据的可发现、可获取、可互操作和可重用4个维度进行具体分析,明确科技期刊关联数据出版的要素。【结果】 结合我国科技期刊发展现状及规划,通过共享分级并将数据出版要素纳入其中,提出符合国际数据共享政策、面向我国科技期刊的关联数据出版通用数据政策框架。【结论】 所提出的期刊关联数据共享分级策略,可为不同期刊数据政策的制订提供参考。 相似文献
63.
新中国成立以来,党和国家不断强化医疗卫生建设,70余年来医疗卫生政策演进呈钟摆式变迁的特征,即从公益导向的福利性医疗卫生政策摆向效率导向的市场化政策,再摆向公益为主兼顾效率的民生导向政策,在公益与效率间发生三次摆动。本文借助政策反馈理论分析医疗卫生政策钟摆式变迁的内在逻辑,发现政策变迁过程中原有政策通过资源效应、解释效应、演化效应和学习效应影响新政策的制定,使得新政策留有原政策的烙印,呈现出摆动式变迁而非剧烈或范式变迁。政策反馈理论为医疗卫生政策制定提供新视角,制定医疗卫生政策需注重原政策的历史影响力,以公共价值引领医疗医保医药政策,从多重政策反馈效应视角出发优化卫生政策的制定。 相似文献
64.
《Disability and health journal》2021,14(4):101122
BackgroundDisability faced by a young person can impact the school-to-work transition and shape health and well-being over the life course. Unique barriers to entry and advancement within the labor market that are relevant to young people with disabilities underscore the need for tailored policy-level supports.ObjectivesTo examine and describe policies that support the school-to-work transition of young people with disabilities in Canada.MethodsA scan of policies which focused on the school-to-work transition of young people with disabilities across Canada was conducted between June 2019 and January 2020. Searches were completed within federal, provincial and territorial policy portals. Each policy relating to employment participation of people with disabilities was summarized. Policies that focused on the school-to-work-specific were synthesized using Bemelmans-Vidic, Rist and Vedung's policy tool framework.ResultsA total of 36 policies were identified by our scan that focused on the employment of people with disabilities. Only five policies explicitly addressed the school-to-work transition. All existing policies were implemented at the provincial level and aimed to promote entry into employment. The synthesis of policies revealed that financial policy tools were primarily used to incentivize employment, provision of workplace accommodations, or the development and implementation of job readiness programs.ConclusionOur analysis of federal, provincial and territorial policies in Canada uncovered a limited number of policies that specifically support the school-to-work transition. Addressing these policy gaps can increase the inclusion of young people with disabilities in the labor market. 相似文献
65.
Yumi Oh 《Yebang Ŭihakhoe chi》2021,54(3):173
The National Health Plan 2030 (HP2030) started to be prepared in 2017 and was completed and announced in December 2020. This study presents an overview of how it was established, the major changes in policies, its purpose, and future directions. This study analyzed the steps taken in the past 4 years to establish HP2030 and reviewed major issues at the international and governmental levels based on an evaluation of HP2020 and its content. HP2030 establishes 6 divisions and 28 topic areas, and it will continue to expand investments in health with a total budget of 2.5 trillion Korean won. It also established goals to enhance health equity for the first time, with the goal of calculating healthy life expectancy in a way that reflects the circumstances of Korea and reducing the gap in income and healthy life expectancy between regions. The establishment of HP2030 is significant in that it constitutes a sustainable long-term plan with sufficient preparation, contains policy measures that everyone participates in and makes together, and works towards improvements in universal health standards and health equity. With the announcement of HP2030, which includes goals and directions of the national health policy for the next 10 years, it will be necessary to further strengthen collaboration with relevant ministries, local governments, and agencies in various fields to concretize support for prevention-centered health management as a national task and to develop a health-friendly environment that considers health in all policy areas. 相似文献
66.
Melissa L. Desroches Sarah Ailey Kathleen Fisher Judith Stych 《Disability and health journal》2021,14(1):101015
BackgroundPeople with developmental disabilities (DD) are a population at high-risk for poor outcomes related to COVID-19. COVID-19-specific risks, including greater comorbidities and congregate living situations in persons with DD compound existing health disparities. With their expertise in care of persons with DD and understanding of basic principles of infection control, DD nurses are well-prepared to advocate for the needs of people with DD during the COVID-19 pandemic.ObjectiveTo assess the challenges faced by nurses caring for persons with DD during the COVID-19 pandemic and how the challenges impact people with DD.MethodsWe surveyed 556 DD nurses, from April 6–20, 2020. The 35-item mixed-method survey asked nurses to rate the degree of challenges faced in meeting the care needs of people with DD. We analyzed responses based on presence of COVID-19 in the care setting and geographically. One open-ended question elicited challenges not included in the survey, which we analyzed using manifest content analysis.ResultsStartlingly, nurses reported being excluded from COVID-19 planning, and an absence of public health guidelines specific to persons with DD, despite their high-risk status. Obtaining PPE and sanitizers and meeting social-behavioral care needs were the most highly ranked challenges. COVID-19 impacted nurses’ ability to maintain adequate staffing and perform essential aspects of care. No significant geographic differences were noted.ConclusionsDD nurses must be involved in public health planning and policy development to ensure that basic care needs of persons with DD are met, and the disproportionate burden of COVID-19 in this vulnerable population is reduced. 相似文献
67.
Jessica Packer Simon J. Russell Deborah Ridout Steven Hope Anne Conolly Curtis Jessop Oliver J. Robinson Sandro T. Stoffel Russell M. Viner Helen Croker 《Nutrients》2021,13(3)
Front of pack food labels (FOPLs) provide accessible nutritional information to guide consumer choice. Using an online experiment with a large representative British sample, we aimed to examine whether FOPLs improve participants’ ability to identify the healthiness of foods and drinks. The primary aim was to compare ability to rank between FOPL groups and a no label control. Adults (≥18 years), recruited from the NatCen panel, were randomised to one of five experimental groups (Multiple Traffic Light, MTL; Nutri-Score, N-S; Warning Label, WL; Positive Choice tick, PC; no label control). Stratification variables were year of recruitment to panel, sex, age, government office region, and household income. Packaging images were created for three versions, varying in healthiness, of six food and drink products (pizza, drinks, cakes, crisps, yoghurts, breakfast cereals). Participants were asked to rank the three product images in order of healthiness. Ranking was completed on a single occasion and comprised a baseline measure (with no FOPL), and a follow-up measure including the FOPL as per each participant’s experimental group. The primary outcome was the ability to accurately rank product healthiness (all products ranked correctly vs. any incorrect). In 2020, 4504 participants had complete data and were included in the analysis. The probability of correct ranking at follow-up, and improving between baseline and follow-up, was significantly greater across all products for the N-S, MTL and WL groups, compared to control. This was seen for only some of the products for the PC group. The largest effects were seen for N-S, followed by MTL. These analyses were adjusted for stratification variables, ethnicity, education, household composition, food shopping responsibility, and current FOPL use. Exploratory analyses showed a tendency for participants with higher compared to lower education to rank products more accurately. Conclusions: All FOPLs were effective at improving participants’ ability to correctly rank products according to healthiness in this large representative British sample, with the largest effects seen for N-S, followed by MTL. 相似文献
68.
69.
《Journal of the Academy of Nutrition and Dietetics》2021,121(4):678-687.e1
BackgroundNationally, approximately one-third of early childhood education centers participating in the Child and Adult Care Food Program (CACFP) are independently owned and operated (ie, not owned by a corporation, not affiliated with Head Start, and with no food program sponsor). Independent providers are less likely to meet CACFP standards and best practices and would benefit from additional support and technical assistance.ObjectiveTo explore independent early childhood education center key informants’ (KIs) (ie, directors or relevant staff) perspectives on implementing the revised CACFP standards.DesignFollowing qualitative exploratory design, semistructured, in-depth, telephone interviews were conducted with KIs individually.Participants/settingIn summer 2018, 30 randomly sampled KIs from independent CACFP-participating early childhood education centers serving children ages 2 to 5 years nationwide were interviewed. Participants were sampled from respondents to a previously completed nationwide survey of providers.Main outcomesKIs’ perspectives on the CACFP program and revised meal pattern standard implementation.Analysis performedAfter audio recordings were professionally transcribed and reviewed, constant comparative analysis was conducted using Atlas.ti v8 qualitative software (Atlas.ti. version 8 for Windows, 2018, Scientific Software Development GmbH).ResultsKIs indicated that program benefits (eg, health and nutrition benefits, reimbursement, guidelines, and training) outweighed challenges experienced. Challenges associated with revised CACFP standards implementation (eg, availability or acceptability of new, creditable foods) were impacted by enhanced CACFP standards status, reported revised standards, and availability or utilization of outside support. KIs desired more contact with their state representative. KIs found the training and technical assistance on the revised standards useful and suggestions to enhance future training and technical assistance (eg, increasing accessibility, training resources, and audience-specific training).ConclusionsOverall, KIs desired additional resources, training, and increased communication from CACFP state representatives specific to CACFP-approved and reimbursable products, menu ideas, recipes, and cooking demonstrations. The present study suggests that a more tailored training and technical assistance approach is necessary as reported benefits, challenges, and program needs varied based on state-enhanced CACFP standards, reported familiarity with the revised meal pattern, and reported outside support. 相似文献
70.
Modelling and simulation methods can play an important role in guiding public health responses to infectious diseases and emerging health threats by projecting the plausible outcomes of decisions and interventions. The 2003 SARS epidemic marked a new chapter in disease modelling in Canada as it triggered a national discussion on the utility and uptake of modelling research in local and pandemic outbreaks. However, integration and application of model-based outcomes in public health requires knowledge translation and contextualization. We reviewed the history and performance of Pan-InfORM (Pandemic Influenza Outbreak Research Modelling), which created a national infrastructure in Canada with a mandate to develop innovative knowledge translation methodologies to inform policy makers through modelling frameworks that bridge the gaps between theory, policy, and practice. This review demonstrates the importance of a collaborative infrastructure as a “Community of Practice” to guide public health responses, especially in the context of emerging diseases with substantial uncertainty, such as the COVID-19 pandemic. Dedicated resources to modelling and knowledge translation activities can help create synergistic strategies at the global scale and optimize public health responses to protect at-risk populations and quell socioeconomic and health burden. 相似文献