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   1666篇
  免费   250篇
  国内免费   21篇
耳鼻咽喉   10篇
儿科学   58篇
妇产科学   37篇
基础医学   91篇
口腔科学   73篇
临床医学   270篇
内科学   433篇
皮肤病学   42篇
神经病学   60篇
特种医学   298篇
外科学   133篇
综合类   18篇
预防医学   287篇
眼科学   12篇
药学   31篇
肿瘤学   84篇
  2024年   3篇
  2023年   53篇
  2022年   16篇
  2021年   12篇
  2020年   40篇
  2019年   18篇
  2018年   52篇
  2017年   33篇
  2016年   45篇
  2015年   54篇
  2014年   95篇
  2013年   118篇
  2012年   34篇
  2011年   49篇
  2010年   63篇
  2009年   81篇
  2008年   48篇
  2007年   73篇
  2006年   51篇
  2005年   43篇
  2004年   40篇
  2003年   17篇
  2002年   17篇
  2001年   27篇
  2000年   22篇
  1999年   28篇
  1998年   66篇
  1997年   89篇
  1996年   79篇
  1995年   57篇
  1994年   63篇
  1993年   52篇
  1992年   16篇
  1991年   15篇
  1990年   33篇
  1989年   43篇
  1988年   33篇
  1987年   36篇
  1986年   34篇
  1985年   32篇
  1984年   16篇
  1983年   13篇
  1982年   24篇
  1981年   30篇
  1980年   17篇
  1979年   8篇
  1978年   5篇
  1977年   15篇
  1976年   14篇
  1975年   10篇
排序方式: 共有1937条查询结果,搜索用时 0 毫秒
41.
Coronavirus disease 2019 (COVID-19) continues to impact older adults disproportionately with respect to serious consequences ranging from severe illness and hospitalization to increased mortality risk. Concurrently, concerns about potential shortages of healthcare professionals and health supplies to address these issues have focused attention on how these resources are ultimately allocated and used. Some strategies, for example, misguidedly use age as an arbitrary criterion that disfavors older adults in resource allocation decisions. This is a companion article to the American Geriatrics Society (AGS) position statement, “Resource Allocation Strategies and Age-Related Considerations in the COVID-19 Era and Beyond.” It is intended to inform stakeholders including hospitals, health systems, and policymakers about ethical considerations that should be considered when developing strategies for allocation of scarce resources during an emergency involving older adults. This review presents the legal and ethical background for the position statement and discusses these issues that informed the development of the AGS positions: (1) age as a determining factor, (2) age as a tiebreaker, (3) criteria with a differential impact on older adults, (4) individual choices and advance directives, (5) racial/ethnic disparities and resource allocation, and (6) scoring systems and their impact on older adults. It also considers the role of advance directives as expressions of individual preferences in pandemics. J Am Geriatr Soc 68:1143–1149, 2020.  相似文献   
42.
43.
Association between elevated neutrophil defensin levels and endometritis   总被引:4,自引:0,他引:4  
The role of host defenses in the pathogenesis of pelvic inflammatory disease (PID) remains largely uncharacterized. The antimicrobial peptides defensins are important components of innate host defense. To explore the relationship between neutrophil defensins and upper genital tract infection, 377 women who were at risk for PID were enrolled in a study. Women infected with Neisseria gonorrhoeae, Trichomonas vaginalis, or Chlamydia trachomatis had higher median levels of neutrophil defensins (human neutrophil peptides 1-3) in the vagina than did uninfected women. Neutrophil defensins were strongly associated with the presence of endometritis after the analysis was controlled for the presence of sexually transmitted diseases. Vaginal neutrophils were associated with endometritis only in the presence of elevated defensin levels, which highlights the importance of neutrophil activation, rather than the presence of neutrophils alone, in this inflammatory process. Neutrophil defensins appear to participate in the host defense in ascending pelvic infection and the pathogenesis of PID.  相似文献   
44.
45.
46.
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   
47.
48.
49.
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   
50.
Intra-articular Chlamydial Antigen and Inflammatory Arthritis   总被引:1,自引:0,他引:1  
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   
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