全文获取类型
收费全文 | 1632篇 |
免费 | 251篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 58篇 |
妇产科学 | 26篇 |
基础医学 | 92篇 |
口腔科学 | 73篇 |
临床医学 | 270篇 |
内科学 | 422篇 |
皮肤病学 | 38篇 |
神经病学 | 60篇 |
特种医学 | 295篇 |
外科学 | 123篇 |
综合类 | 18篇 |
预防医学 | 288篇 |
眼科学 | 11篇 |
药学 | 36篇 |
肿瘤学 | 85篇 |
出版年
2023年 | 48篇 |
2022年 | 13篇 |
2021年 | 11篇 |
2020年 | 40篇 |
2019年 | 18篇 |
2018年 | 52篇 |
2017年 | 33篇 |
2016年 | 44篇 |
2015年 | 54篇 |
2014年 | 95篇 |
2013年 | 119篇 |
2012年 | 33篇 |
2011年 | 48篇 |
2010年 | 64篇 |
2009年 | 81篇 |
2008年 | 49篇 |
2007年 | 74篇 |
2006年 | 52篇 |
2005年 | 36篇 |
2004年 | 38篇 |
2003年 | 17篇 |
2002年 | 14篇 |
2001年 | 27篇 |
2000年 | 24篇 |
1999年 | 31篇 |
1998年 | 66篇 |
1997年 | 89篇 |
1996年 | 79篇 |
1995年 | 58篇 |
1994年 | 62篇 |
1993年 | 52篇 |
1992年 | 17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 | 13篇 |
1983年 | 13篇 |
1982年 | 24篇 |
1981年 | 30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1904条查询结果,搜索用时 15 毫秒
51.
52.
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
53.
54.
55.
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
56.
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
57.
58.
JD Carver 《Acta paediatrica (Oslo, Norway : 1992)》1999,88(S430):83-88
Nucleotides (NT) and their related metabolic products play key roles in many biological processes. NT can be synthesized endogenously and thus are not considered essential nutrients. Studies have demonstrated, however, that dietary NT can have beneficial effects; the term "conditionally essential" has been used to describe their role in human nutrition. These nutrients may become essential when the endogenous supply is insufficient for normal function, even though their absence from the diet does not lead to a classic clinical deficiency syndrome. Most dietary NT are rapidly metabolized and excreted. However, some are incorporated into tissues, particularly at younger ages and with fasting. Under conditions of limited NT intake, rapid growth or certain disease states, dietary NT may spare the cost of de novo NT synthesis and optimize the function of rapidly dividing tissues such as those of the gastrointestinal and immune systems. Animals fed NT-supplemented versus non-NT supplemented diets have enhanced gastrointestinal growth and maturation, and improved recovery following small and large bowel injury. Indices of humoral and cellular immunity are enhanced, and survival rates are higher following infection with pathogens. Infants receive NT in human milk, where they are present as nucleic acids, nucleosides, nucleotides and related metabolic products. The NT content of human milk is significantly higher than most cow's milk-based infant formulae. Dietary NT are reported to enhance the gastrointestinal and immune systems of formula-fed infants. Infants fed NT-supplemented versus non-supplemented formula have a lower incidence of diarrhea, higher antibody titers following Haemophilus influenzae type b vaccination and higher natural killer cell activity. These data suggest that human milk NT may contribute to the superior clinical performance of the breastfed infant. 相似文献
59.
JD Roberts JC Herkert J Rutberg SM Nikkel ACP Wiesfeld D Dooijes RM Gow JP van Tintelen MH Gollob 《Clinical genetics》2013,83(5):452-456
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited myocardial disease that predominantly affects the right ventricle and is associated with ventricular arrhythmias that may lead to sudden cardiac death. Mutations within at least seven separate genes have been identified to cause ARVC, however a genetic culprit remains elusive in approximately 50% of cases. Although negative genetic testing may be secondary to pathogenic mutations within undiscovered genes, an alternative explanation may be the presence of large deletions or duplications involving known genes. These large copy number variants may not be detected with standard clinical genetic testing which is presently limited to direct DNA sequencing. We describe two cases of ARVC possessing large deletions involving plakophilin‐2 (PKP2) identified with microarray analysis and/or multiplex ligation‐dependent probe amplification (MLPA) that would have been classified as genotype negative with standard clinical genetic testing. A deletion of the entire coding region of PKP2 excluding exon 1 was identified in patient 1 and his son. In patient 2, MLPA analysis of PKP2 revealed deletion of the entire gene with subsequent microarray analysis demonstrating a de novo 7.9 Mb deletion of chromosome 12p12.1p11.1. These findings support screening for large copy number variants in clinically suspected ARVC cases without clear disease causing mutations following initial sequencing analysis. 相似文献