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   1352877篇
  免费   104771篇
  国内免费   6307篇
医药卫生   1463955篇
  2021年   11573篇
  2019年   12636篇
  2018年   17341篇
  2017年   13325篇
  2016年   14202篇
  2015年   16514篇
  2014年   22528篇
  2013年   33618篇
  2012年   46481篇
  2011年   49271篇
  2010年   28554篇
  2009年   26104篇
  2008年   44283篇
  2007年   46557篇
  2006年   46568篇
  2005年   44988篇
  2004年   42520篇
  2003年   40423篇
  2002年   39092篇
  2001年   61445篇
  2000年   62871篇
  1999年   52476篇
  1998年   14046篇
  1997年   12591篇
  1996年   12413篇
  1995年   12631篇
  1994年   11808篇
  1993年   10997篇
  1992年   41659篇
  1991年   40911篇
  1990年   39547篇
  1989年   37427篇
  1988年   34651篇
  1987年   33738篇
  1986年   32172篇
  1985年   30673篇
  1984年   23013篇
  1983年   19558篇
  1982年   11693篇
  1979年   20772篇
  1978年   14774篇
  1977年   12021篇
  1976年   11839篇
  1975年   12085篇
  1974年   14778篇
  1973年   14457篇
  1972年   13353篇
  1971年   12413篇
  1970年   11476篇
  1969年   10404篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Abstract

Introduction: ASPIRE Excellence Awards in Student Assessment are offered to medical schools with innovative and comprehensive assessment programmes adjudged by international experts, using evidence-based criteria.

The journeys of three ASPIRE-winning medical schools toward “assessment excellence” are presented. These schools include Aga Khan University Medical College (AKU-MC), Pakistan, Southern Illinois University School of Medicine (SIUSOM), USA, and University of Leeds School of Medicine, UK.

Methods: The unfolding journeys highlighting achievements, innovations, and essential components of each assessment programme were compared to identify differences and commonalities.

Results: Cultural contextual differences included developed-versus-developing country, east-west, type of regulatory bodies, and institutional-versus-national certifying/licensing examinations, which influence curricula and assessments.

In all, 12 essential commonalities were found: alignment with institutional vision; sustained assessment leadership; stakeholder engagement; communication between curriculum and assessment; assessment-for-learning and feedback; longitudinal student profiling of outcome achievement; assessment rigor and robustness; 360° feedback from-and-to assessment; continuous enrichment through rigorous quality assurance; societal sensitivity; influencing others; and a “wow factor.”

Conclusions: Although the journeys of the three medical schools were undertaken in different cultural contexts, similar core components highlight strong foundations in student assessment. The journeys continue as assessment programmes remain dynamic and measurement science expands. This article may be helpful to other institutions pursuing excellence in assessment.  相似文献   
102.
Background: In an interprofessional training ward (ITW), students from different health professions collaboratively perform patient care with the goal of improving patient care. In the past two decades, ITWs have been established world-wide and studies have investigated their benefits. We aimed to compare ITWs with respect to their logistics, interprofessional learning outcomes and patient outcomes.

Methods: We explored PubMed, CINAHL, Web of Science and EMBASE (1990–June 2017) and included articles focusing on interprofessional, in-patient training wards with student teams of medical and other health professions students. Two independent reviewers screened studies for eligibility and extracted data.

Results: Thirty-seven articles from twelve different institutions with ITWs were included. ITWs world-wide are organized similarly with groups of 2–12 students (i.e. medical, nursing, physiotherapy, occupational therapy, and pharmacy) being involved in patient care, usually for a period of two weeks. However, the type of clinical ward and the way supervisors are trained differ.

Conclusions: ITWs show promising results in short-term student learning outcomes and patient satisfaction rates. Future ITW studies should measure students’ long-term interprofessional competencies using standardized tools. Furthermore, a research focus on the impact of ITWs on patient satisfaction and relevant patient care outcomes is important.  相似文献   

103.
Background: The use of improvizational theater (“improv”) in health professional education (“medical improv”) is an emerging field. However, optimal curricular design features and learning outcomes have not yet been systematically described.

Objective: To synthesize evidence on learning outcomes and curricular design elements of improvizational theater training in health professions education.

Methods: A literature search with keywords “Improv” and “Improvisational Theatre” was undertaken in January 2016 in Ovid MEDLINE, CINHAL, EMBASE, SCOPUS, Web of Science, and ERIC, with an accompanying gray literature search. Four authors coded and achieved consensus on themes relating to curricular design elements and learning outcomes, which were mapped onto the CanMEDS framework.

Results: Seven articles met inclusion criteria. Key curricular design features included (i) facilitators with dual clinical and theater expertise; (ii) creating a low-stakes environment; and (iii) engaging in debrief to highlight clinical relevance. Improv curricula were found to impact most CanMEDS roles, including: Medical Expert (comfort with uncertainty); Leader (team management); Scholar (feedback, self-reflection); Communicator (empathy, active listening, non-verbal communication); Collaborator (culture of trust); and Professional (resiliency and confidence). Mechanisms by which improv may promote acquisition of these professional competencies, and the utility of improv in areas such as interprofessional team development, leadership, and wellness and resiliency are discussed.  相似文献   

104.
ObjectiveIdentify factors associated with healthcare providers' frequency of depot medroxyprogesterone acetate (DMPA) provision to adolescents.Study designWe analyzed data from surveys mailed to a nationally representative sample of public-sector providers and office-based physicians (n=1984). We estimated adjusted odds ratios (aORs) and 95% confidence intervals (CIs) of factors associated with frequent DMPA provision to adolescents in the past year.ResultsAlthough most providers (>95%) considered DMPA safe for adolescents, fewer reported frequent provision (89% of public-sector providers; 64% of office-based physicians). Among public-sector providers, factors associated with lower odds of frequent provision included working in settings without Title X funding (aOR 0.44, 95% CI 0.30–0.64), reporting primary care as their primary clinical focus versus reproductive or adolescent health (aOR 0.42, 95% CI 0.28–0.61), and providing fewer patients with family planning services. Among office-based physicians, factors associated with lower odds of frequent provision included specializing in obstetrics/gynecology (aOR 0.50, 95% CI 0.27–0.91) and family medicine (aOR 0.21, 95% CI 0.09–0.47) versus adolescent medicine, completing training ≥15 versus <5 years ago (aOR 0.27, 95% CI 0.09–0.83), and reporting that 0–24% of patients pay with Medicaid or other government healthcare assistance versus ≥50% (aOR 0.23, 95% CI 0.09–0.61). The reason most commonly reported by providers for infrequent DMPA provision was patient preference for another method.ConclusionsWhile most providers reported frequently providing DMPA to adolescents, training on evidence-based recommendations for contraception, focused on subgroups of providers with lower odds of frequent DMPA provision, may increase adolescents' access to contraception.ImplicationsAlthough >95% of providers considered depot medroxyprogesterone (DMPA) a safe contraceptive for adolescents, only 89% of public-sector providers and 64% of office-based physicians reported frequently providing DMPA to adolescents. Provider training on evidence-based recommendations for contraception counseling and provision may increase adolescents' access to DMPA and all methods of contraception.  相似文献   
105.
Access to safe and effective contraceptive choices is a reproductive right and contributes tremendously to improvements in maternal and child health. Progestin-only injectables, particularly intramuscularly injected depot medroxyprogesterone acetate (DMPA-IM), have received increased attention given findings suggesting a potential association with increased HIV risk. For women at high risk of HIV, the World Health Organization's Medical eligibility criteria for contraceptive use currently aggregate recommendations for all progestin-only injectables, including DMPA-IM, subcutaneously injected DMPA (DMPA-SC) and intramuscularly injected norethindrone/ norethisterone enanthate (NET-EN), except in the case of some drug interactions. We considered whether published data indicate differences or similarities between these injectables relevant to risk of acquiring HIV. In vitro data confirm different biological activities of these distinct progestins, including that MPA, and not NET, binds and activates the glucocorticoid receptor resulting in different biological effects relevant to immune function. Limited clinical data suggest changes in immunologic activity following DMPA-IM and NET-EN initiation, but interstudy variation and study design differences diminish ability to determine clinical relevance and the degree to which DMPA-IM and NET-EN could act differentially. The highest-quality epidemiologic studies suggest a potential 40% increase in HIV incidence in users of DMPA-IM relative to women not using hormonal contraception but no significant increase in risk in users of NET-EN. In our opinion, most of the available biologic activity and epidemiologic data indicate that DMPA and NET-EN are likely to act differently, and data remain too limited to evaluate differences between DMPA-IM and DMPA-SC.  相似文献   
106.

Objective

The objective was to evaluate the pharmacokinetics (PKs) of levonorgestrel (LNG)-containing combined oral contraceptives (COCs) in obese women.

Study design

We pooled and reanalyzed data from 89 women with different body mass index (BMI) categories from four clinical studies. The LNG and ethinyl estradiol (EE) PKs were analyzed utilizing a zero-order absorption (K0), two-compartment PK model to evaluate key PK parameters in relation to a range of weights, BMI and body surface area (BSA).

Results

Increasing of body habitus metrics is correlated with decreasing Cmax (p<.0001) and AUCτ (p<.05) for both LNG and EE, but no correlation was found for Cmin (p≥.17). Increasing weight and BMI were associated with a modest increase (p≤.056) of clearance (CL) and appreciable increases of central volume (V1, p<.05), distribution clearance (CLd, p≤.001) and peripheral volume (V2, p<.0001) for LNG. For EE, increases in CL (p≤.009) were found with greater weight, BMI and BSA. Values of V1, CLd and V2 also increased (p<.0001) in obese subjects. The half-life and steady-state volume were greater among obese women (p<.0001) for both LNG and EE. LNG and EE PK parameters correlated well (p≤.006 for all), indicating that individual subject physiology affected both drugs similarly.

Conclusions

The primary effects of obesity on LNG and EE were a modest increase in CL and a marked increase in distribution parameters. We observed no obesity-related differences in trough LNG and EE concentrations.

Implications

This population PK analysis demonstrated reduced systemic exposure to LNG/EE oral contraceptives in obese subjects (Cmax and AUCτ); these particular differences are unlikely to lower contraceptive effectiveness among obese women who are correctly using LNG-containing contraceptives.  相似文献   
107.
108.
109.
110.
Introduction: Consumption of nuts, which contain multiple anti-carcinogenic components, has been inversely associated with colorectal cancer (CRC), particularly among women, but has not been investigated in relation to colorectal adenoma, the immediate precursor to most CRCs.

Methods: We pooled data from three case-control studies of incident, sporadic colorectal adenoma (n?=?785 cases, 2107 controls) in which dietary intakes were assessed using food frequency questionnaires, and analyzed the data using multivariable unconditional logistic regression.

Results: Among men and women combined, the multivariable-adjusted odds ratios (OR) and 95% confidence intervals (CI) for the association of total nut product (all nuts and peanut butter combined) intakes, for those who consumed 0.5–1.5, 2.0–5.5, and ≥6 servings/week relative to no nut consumption were 0.81 (0.58, 1.12), 0.86 (0.61, 1.23), and 0.93 (0.65, 1.31), respectively. However, among women, the corresponding ORs and 95% CIs were 0.62 (0.40, 0.97), 0.57 (0.35, 0.94), and 0.78 (0.48, 1.25), respectively.

Conclusions: These results suggest that moderate nut consumption may be associated with lower risk for colorectal adenoma, primarily among women.  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