全文获取类型
收费全文 | 1728篇 |
免费 | 252篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 59篇 |
妇产科学 | 26篇 |
基础医学 | 96篇 |
口腔科学 | 73篇 |
临床医学 | 273篇 |
内科学 | 433篇 |
皮肤病学 | 38篇 |
神经病学 | 126篇 |
特种医学 | 297篇 |
外科学 | 139篇 |
综合类 | 18篇 |
预防医学 | 289篇 |
眼科学 | 11篇 |
药学 | 30篇 |
肿瘤学 | 84篇 |
出版年
2023年 | 48篇 |
2022年 | 13篇 |
2021年 | 11篇 |
2020年 | 41篇 |
2019年 | 20篇 |
2018年 | 55篇 |
2017年 | 33篇 |
2016年 | 46篇 |
2015年 | 54篇 |
2014年 | 97篇 |
2013年 | 128篇 |
2012年 | 51篇 |
2011年 | 66篇 |
2010年 | 69篇 |
2009年 | 86篇 |
2008年 | 60篇 |
2007年 | 82篇 |
2006年 | 57篇 |
2005年 | 41篇 |
2004年 | 43篇 |
2003年 | 20篇 |
2002年 | 15篇 |
2001年 | 25篇 |
2000年 | 24篇 |
1999年 | 28篇 |
1998年 | 65篇 |
1997年 | 89篇 |
1996年 | 79篇 |
1995年 | 57篇 |
1994年 | 62篇 |
1993年 | 52篇 |
1992年 | 16篇 |
1991年 | 12篇 |
1990年 | 31篇 |
1989年 | 42篇 |
1988年 | 31篇 |
1987年 | 34篇 |
1986年 | 33篇 |
1985年 | 32篇 |
1984年 | 14篇 |
1983年 | 13篇 |
1982年 | 24篇 |
1981年 | 31篇 |
1980年 | 17篇 |
1979年 | 7篇 |
1978年 | 5篇 |
1977年 | 14篇 |
1976年 | 14篇 |
1975年 | 10篇 |
1969年 | 2篇 |
排序方式: 共有2001条查询结果,搜索用时 10 毫秒
51.
Sharmistha Dev MD MPH Andrew A. Gonzalez MD JD MPH Jessica Coffing MPH James E. Slaven MS Shantanu Dev BS Stan Taylor MA Carrie Ballard S. Nicole Hastings MD MHSc Dawn M. Bravata MD 《Academic emergency medicine》2023,30(4):349-358
Objectives
Frailty is a clinical syndrome characterized by decreased physiologic reserve that diminishes the ability to respond to stressors such as acute illness. Veterans Health Administration (VA) emergency departments (ED) are the primary venue of care for Veterans with acute illness and represent key sites for frailty recognition. As questionnaire-based frailty instruments can be cumbersome to implement in the ED, we examined two administratively derived frailty scores for use among VA ED patients.Methods
This national retrospective cohort study included all VA ED visits (2017–2020). We evaluated two administratively derived scores: the Care Assessment Needs (CAN) score and the VA Frailty Index (VA-FI). We categorized all ED visits across four frailty groups and examined associations with outcomes of 30-day and 90-day hospitalization and 30-day, 90-day, and 1-year mortality. We used logistic regression to assess the model performance of the CAN score and the VA-FI.Results
The cohort included 9,213,571 ED visits. With the CAN score, 28.7% of the cohort were classified as severely frail; by VA-FI, 13.2% were severely frail. All outcome rates increased with progressive frailty (p-values for all comparisons < 0.001). For example, for 1-year mortality based on the CAN score frailty was determined as: robust, 1.4%; prefrail, 3.4%; moderately frail, 7.0%; and severely frail, 20.2%. Similarly, for 90-day hospitalization based on VA-FI, frailty was determined as prefrail, 8.3%; mildly frail, 15.3%; moderately frail, 29.5%; and severely frail, 55.4%. The c-statistics for CAN score models were higher than for VA-FI models across all outcomes (e.g., 1-year mortality, 0.721 vs. 0.659).Conclusions
Frailty was common among VA ED patients. Increased frailty, whether measured by CAN score or VA-FI, was strongly associated with hospitalization and mortality and both can be used in the ED to identify Veterans at high risk for adverse outcomes. Having an effective automatic score in VA EDs to identify frail Veterans may allow for better targeting of scarce resources. 相似文献52.
53.
A diaper bank and home visiting partnership: Initial exploration of research and policy questions 下载免费PDF全文
54.
55.
Benjamin C. Sun MD MPP Helen R. Burstin MD MPH Troyen A. Brennan MD JD MPH 《Academic emergency medicine》2003,10(4):320-328
OBJECTIVE: To identify predictors and outcomes associated with frequent emergency department (ED) users. METHODS: Cross-sectional intake surveys, medical chart reviews, and telephone follow-up interviews of patients presenting with selected chief complaints were performed at five urban EDs during a one-month study period in 1995. Frequent use was defined by four or more self-reported, prior ED visits. Multivariate logistic regression identified predictors of frequent ED visitors from five domains (demographics, health status, health access, health care preference, and severity of acute illness). Associations between high use and selected outcomes were assessed with logistic regression models. RESULTS: All study components were completed by 2,333 of 3,455 eligible patients (67.5%). Demographics predicting frequent use included being a single parent, single or divorced marital status, high school education or less, and income of less than $10,000 (1995). Health status predictors included hospitalization in the preceding three months, high ratings of psychological distress, and asthma. Health access predictors included identifying an ED or a hospital clinic as the primary care site, having a primary care physician (PCP), and visiting a PCP in the past month. Choosing the ED for free care was the only health preference predictive of heavy use. Illness severity measures were higher in frequent visitors, although these were not independently predictive in the multivariate model. Outcomes correlated with heavy use include increased hospital admissions, higher rates of ED return visits, and lower patient satisfaction, but not willingness to return to the ED or follow-up with a doctor. CONCLUSIONS: Frequent ED visits are associated with socioeconomic distress, chronic illness, and high use of other health resources. Efforts to reduce ED visits require addressing the unique needs of these patients in the emergency and primary care settings. 相似文献
56.
57.
58.
Dr. Jerome M. Creenberg MD Bruce H. Dobun MD MPH David W. Shapiro MD JD Lawrence S. Linn PhD Neil S. Wenger MD MPH 《Journal of general internal medicine》1993,8(12):683-685
Advance directives, such as the durable power of attorney for health care (DPAHC), help patients and physicians make end-of-life health care decisions. Medical education should prepare student physicians to be knowledgeable about and comfortable with discussing advance directives. The authors developed an educational module for the third-year medical school curriculum and conducted a randomized trial to evaluate in students its effect on various outcome measures regarding the DPAHC. Over a six-week period, students who received written material about the DPAHC and a two-hour seminar significantly increased knowledge about and reported increased skill, comfort, and experience with the DPAHC. 相似文献
59.
Intra-articular Chlamydial Antigen and Inflammatory Arthritis 总被引:1,自引:0,他引:1
HUGHES RA; HYDER E; TREHARNE JD; KEAT ACS 《QJM : monthly journal of the Association of Physicians》1991,80(1):575-588
Joint material from 133 patients with well-characterized inflammatoryarthritis, including individuals likely to have suffered reactivearthiritis, was studied. The majority of patients were alsoexamined for the presence of genital tract infection with Chlamydiatrachomatis. Fluorescein-conjugated monoclonal antibodies demonstratedthe presence of C. trachomatis antigen in synovial fluid celldeposits or synovial sections from inflamed knee joints of sevenpatients with reactive arthritis. The significance of thesefindings is discussed, as is the low rate of detection of chlamydialantigen in either the genital tract or the joint from patientsin this study. We emphasize the need for further work aimedat identifying the relevant immunogenic chlamydial antigensresponsible for the initiation of reactive arthritis. 相似文献