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   4456篇
  免费   23篇
  国内免费   5篇
医药卫生   4484篇
  2023年   3篇
  2022年   9篇
  2021年   50篇
  2020年   15篇
  2019年   799篇
  2018年   703篇
  2017年   300篇
  2016年   37篇
  2015年   16篇
  2014年   32篇
  2013年   109篇
  2012年   153篇
  2011年   125篇
  2010年   144篇
  2009年   139篇
  2008年   121篇
  2007年   112篇
  2006年   24篇
  2005年   13篇
  2004年   9篇
  2003年   13篇
  2002年   13篇
  2001年   31篇
  2000年   9篇
  1999年   50篇
  1998年   5篇
  1997年   3篇
  1996年   8篇
  1995年   2篇
  1994年   7篇
  1993年   4篇
  1992年   10篇
  1991年   3篇
  1989年   1篇
  1988年   2篇
  1986年   1篇
  1985年   115篇
  1984年   212篇
  1983年   129篇
  1982年   165篇
  1981年   165篇
  1980年   96篇
  1979年   83篇
  1978年   98篇
  1977年   73篇
  1976年   82篇
  1975年   68篇
  1974年   58篇
  1973年   65篇
排序方式: 共有4484条查询结果,搜索用时 281 毫秒
1.
《Vaccine》2020,38(45):7118-7128
IntroductionToward the Global Vaccine Action Plan 2020 goal, almost 90% of countries have established a National Immunization Technical Advisory Group (NITAG). However, little is known about NITAG's contributions to governance.MethodsIn 2017–2018, a two-step, qualitative retrospective study was conducted. Jordan (JO), Argentina (AR), and South Africa (SA) were selected owing to government-financed NITAGs from middle-income countries (MICs), geographic diversity, and a vaccine introduction with NITAG support. Country case studies were developed, collecting data through desk review and face-to-face key informant interviews (KIIs) from Ministry of Health (MoH) and NITAG. Case studies were analyzed together, to assess governance applying the European Observatory on Health Systems and Policies framework focusing on transparency, accountability, participation, integrity, and policy capacity (TAPIC).ResultsDocument review and 53 KII (22 AR, 20 SA, 11 JO) showed NITAGs played a pivotal role as advisors promoting a culture of evidence-informed policies. NITAGs strengthened governance, although practices varied among countries. Meetings were conducted behind-closed-doors, participation restricted to members, only in one country agendas, and recommendations were public (AR). To increase participation, policy capacity, and transparency, countries considered adding experts in communications, advocacy, and economics. AR and SA contemplated including community members. NITAGs functioned autonomously from the government, with no established internal or external monitoring or supervision. NITAG meeting minutes allowed the review of integrity, adherence to terms of reference, standard operating procedures, and conflict of interest (CoI). For the most part, NITAGs abided by their mandates. Significant issues were related to the level of MoH support and oversight of CoI declaration and documentation.ConclusionsSystematically implementing governance approaches could improve processes, better tailor policies, and implementation. The long-term survival and resilience of NITAGs in these countries showed they play a significant role in strengthening governance. Lessons learned could be useful to those promoting country-driven evidence-informed decision-making.  相似文献   
2.
3.
BackgroundAlthough there are robust data about the pathophysiology and prognostic implications of left ventricular (LV) systolic dysfunction in patients with acquired heart disease, similar prognostic data about LV systolic dysfunction are sparse in the tetralogy of Fallot (TOF) population. The purpose of this study was to perform a meta-analysis of all studies that assessed the relationship between LV ejection fraction (LVEF) and cardiovascular adverse events (CAEs) defined as death, aborted sudden death, or sustained ventricular tachycardia.MethodsWe used random-effects models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).ResultsOf the 1,809 citations, 7 studies with 2,854 patients (age 28 ± 4 years) were included. During 5.6 ± 3.4 years' follow-up, there were 82 deaths, 17 aborted sudden cardiac deaths, and 56 sustained ventricular tachycardia events. Overall, CAEs occurred in 5.1% (144 patients). As a continuous variable, LVEF was a predictor of CAE (HR 1.29, 95% CI, 1.09-1.53, P = 0.001) per 5% decrease in LVEF. Similarly, LVEF < 40% was also a predictor of CAE (HR 3.22, 95% CI, 2.16-4.80, P < 0.001).ConclusionsLV systolic dysfunction was an independent predictor of CAE, and we observed a 30% increase in the risk of CAE for every 5% decrease in LVEF, and a 3-fold increase in the risk of CAE in patients with LVEF <40% compared with other patients. These findings underscore the importance of incorporating LV systolic function in clinical risk stratification of patients with TOF and the need to explore new treatment options to address this problem.  相似文献   
4.
Understanding why persons with human immunodeficiency virus (HIV) have accelerated atherosclerosis and its sequelae, including coronary artery disease (CAD) and myocardial infarction, is necessary to provide appropriate care to a large and aging population with HIV. In this review, we delineate the diverse pathophysiologies underlying HIV-associated CAD and discuss how these are implicated in the clinical manifestations of CAD among persons with HIV. Several factors contribute to HIV-associated CAD, with chronic inflammation and immune activation likely representing the primary drivers. Increased monocyte activation, inflammation, and hyperlipidemia present in chronic HIV infection also mirror the pathophysiology of plaque rupture. Furthermore, mechanisms central to plaque erosion, such as activation of toll-like receptor 2 and formation of neutrophil extracellular traps, are also abundant in HIV. In addition to inflammation and immune activation in general, persons with HIV have a higher prevalence than uninfected persons of traditional cardiovascular risk factors, including dyslipidemia, hypertension, insulin resistance, and tobacco use. Antiretroviral therapies, although clearly necessary for HIV treatment and survival, have had varied effects on CAD, but newer generation regimens have reduced cardiovascular toxicities. From a clinical standpoint, this mix of risk factors is implicated in earlier CAD among persons with HIV than uninfected persons; whether the distribution and underlying plaque content of CAD for persons with HIV differs considerably from uninfected persons has not been definitively studied. Furthermore, the role of cardiovascular risk estimators in HIV remains unclear, as does the role of traditional and emerging therapies; no trials of CAD therapies powered to detect clinical events have been completed among persons with HIV.  相似文献   
5.
Research has shown that increasing numbers of teenagers are going online to find health information, but it is unclear whether there are disparities in the prevalence of online health seeking among young Internet users associated with social and economic conditions. Existing literature on Internet uses by adults indicates that low income, less educated, and minority individuals are less likely to be online health seekers. Based on the analysis of data from the Pew Internet and American Life Project for the US, this study finds that teens of low education parents are either as likely as or even more likely than teens of high education parents to seek online health information. Multiple regression analysis shows that the higher engagement in health seeking by teens of low education parents is related to a lower prevalence of parental Internet use, suggesting that some of these teens may be seeking online health information on behalf of their low education parents. Implications of these findings are discussed in relation to the issues of the digital divide and digital empowerment.  相似文献   
6.
An inverse relationship between workplace status and morbidity is well established; higher job status has been associated with reduced risks of heart disease, hypertension, and injury. Most research on job status, however, has focused on salaried populations, and it remains unclear whether job status operates similarly among hourly workers. Our objectives were to examine whether hourly status itself influences risk of hypertension after adjustment for socioeconomic confounders, and to explore the role of fine-scale job grade on hypertension incidence within hourly and salaried groups. We examined data for 14,999 aluminum manufacturing employees in 11 plants across the U.S., using logistic regression with adjustment for age, sex, race/ethnicity and other individual characteristics. Propensity score restriction was used to identify comparable groups of hourly and salaried employees, reducing confounding by sociodemographic characteristics. Job grade (coded 1 through 30, within hourly and salaried groups) was examined as a more refined measure of job status. Hourly status was associated with an increased risk of hypertension, after propensity restriction and adjustment for confounders. The observed effect of hourly status was stronger among women, although the propensity-restricted cohort was disproportionately male (96%). Among salaried workers, higher job grade was not consistently associated with decreased risk; among hourly employees, however, there was a significant trend, with higher job grades more protective against hypertension. Increasing the stringency of hypertension case criteria also increased the risk of severe or persistent hypertension for hourly employees.  相似文献   
7.
In this study we consider the process of the clinical encounter, and present exemplars of how assumptions of both clinicians and their patients can shift or transform in the course of a diagnostic interview. We examine the process as it is recalled, and further elaborated, in post-diagnostic interviews as part of a collaborative inquiry during reflections with clinicians and patients in the northeastern United States. Rather than treating assumptions by patients and providers as a fixed attribute of an individual, we treat them as occurring between people within a particular social context, the diagnostic interview. We explore the diagnostic interview as a landscape in which assumptions occur (and can shift), navigate the features of this landscape, and suggest that our examination can best be achieved by the systematic comparison of views of the multiple actors in an experience-near manner. We describe what might be gained by this shift in assumptions and how it can make visible what is at stake for clinician and patient in their local moral worlds—for patients, acknowledgment of social suffering, for clinicians how assumptions are a barrier to engagement with minority patients. It is crucial for clinicians to develop this capacity for reflection when navigating the interactions with patients from different cultures, to recognize and transform assumptions, to notice ‘surprises’, and to elicit what really matters to patients in their care.  相似文献   
8.
Researchers usually employ orthogonal arrays or D-optimal designs with little or no attribute overlap in stated-choice surveys. The challenge is to balance statistical efficiency and respondent burden to minimize the overall error in the survey responses. This study examined whether simplifying the choice task, by using a design with more overlap, provides advantages over standard minimum-overlap methods. We administered two designs for eliciting HIV test preferences to split samples. Surveys were undertaken at four HIV testing locations in San Francisco, California. Personal characteristics had different effects on willingness to pay for the two treatments, and gains in statistical efficiency in the minimal-overlap version more than compensated for possible imprecision from increased measurement error.  相似文献   
9.
Global self-rated health (SRH) is increasingly a key indicator in the assessment of immigrant health. However, evidence of the impact on SRH of generational status, duration of residence in the US, and socioeconomic status (SES) among immigrants and their offspring is limited and inconsistent. We overcome limitations in existing research on this topic by using a uniquely large and diverse data source, the March Annual Social and Economic Supplement of the Current Population Survey (CPS; 2003–2007) (n = 637,209). As a result, we are able to disaggregate results by race/ethnicity, account for country of origin, and consider the role of multiple dimensions of SES. We find that overall first-generation immigrants in the US have lower odds of poor/fair SRH compared to the third-generation. This association is particularly strong for blacks and Hispanics but not significant for Asians. Among first-generation Asians and Hispanics, longer duration of residence is positively associated with poor/fair SRH. Finally, socioeconomic gradients in SRH tend to be less pronounced among the first-generation (versus the third) and, within the first-generation, among recent arrivals (versus those with longer durations). Our results highlight the importance of explicitly accounting for multiple immigration-related variables and their interactions with race/ethnicity and SES. Otherwise, studies may misestimate SRH differences by race/ethnicity and socioeconomic status. The continued growth of the US immigrant population and the second-generation underscore the need to examine patterns in immigrant health systematically.  相似文献   
10.
After 14 years of rising death rates due to unintentional injuries in the U.S., it is time to ask how safety messages can be redesigned to have a greater impact on risky behavior. To this end, many researchers have called for a new, narrative approach to prevention messages—based on persuasive stories about people who have suffered injuries and illnesses in the past. Still, there is scant evidence that story-based communications are more effective than equivalent non-narrative messages at changing actual (rather than self-reported) safety and health behavior. Our research examined the impact of injury stories on actual safety behavior in a controlled experimental setting at a US university. Teams of participants assembled a product (a child's swing) using written instructions. The instructions contained safety messages targeting assembly mistakes that have been linked to serious injuries in children who play on swings. Participant teams were randomly assigned to three conditions: assembly instructions containing story-based safety messages, instructions with concrete (but non-anecdotal) safety messages, and instructions with traditional abstract safety messages. After adjustment for covariates, story-based messages resulted in a 19 percent improvement in safety behavior, compared with non-narrative communications. Importantly, injury stories did not create undue fear of the message object, demonstrating that brief anecdotes about accident victims can convince people to take reasonable precautions without creating unwarranted alarm about risks.  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-23

京公网安备 11010802026262号