全文获取类型
收费全文 | 6640篇 |
免费 | 431篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 58篇 |
儿科学 | 206篇 |
妇产科学 | 323篇 |
基础医学 | 838篇 |
口腔科学 | 108篇 |
临床医学 | 623篇 |
内科学 | 1363篇 |
皮肤病学 | 101篇 |
神经病学 | 568篇 |
特种医学 | 122篇 |
外科学 | 752篇 |
综合类 | 128篇 |
一般理论 | 3篇 |
预防医学 | 674篇 |
眼科学 | 311篇 |
药学 | 430篇 |
中国医学 | 18篇 |
肿瘤学 | 458篇 |
出版年
2024年 | 8篇 |
2023年 | 73篇 |
2022年 | 135篇 |
2021年 | 286篇 |
2020年 | 147篇 |
2019年 | 231篇 |
2018年 | 252篇 |
2017年 | 171篇 |
2016年 | 193篇 |
2015年 | 214篇 |
2014年 | 322篇 |
2013年 | 355篇 |
2012年 | 566篇 |
2011年 | 576篇 |
2010年 | 294篇 |
2009年 | 246篇 |
2008年 | 396篇 |
2007年 | 429篇 |
2006年 | 405篇 |
2005年 | 374篇 |
2004年 | 325篇 |
2003年 | 269篇 |
2002年 | 213篇 |
2001年 | 67篇 |
2000年 | 82篇 |
1999年 | 61篇 |
1998年 | 42篇 |
1997年 | 28篇 |
1996年 | 22篇 |
1995年 | 21篇 |
1994年 | 13篇 |
1993年 | 26篇 |
1992年 | 27篇 |
1991年 | 23篇 |
1990年 | 29篇 |
1989年 | 32篇 |
1988年 | 23篇 |
1987年 | 15篇 |
1986年 | 21篇 |
1985年 | 10篇 |
1984年 | 10篇 |
1983年 | 6篇 |
1981年 | 6篇 |
1979年 | 4篇 |
1977年 | 5篇 |
1973年 | 3篇 |
1970年 | 5篇 |
1969年 | 4篇 |
1968年 | 4篇 |
1967年 | 3篇 |
排序方式: 共有7084条查询结果,搜索用时 15 毫秒
51.
Preliminary Evidence for Subdimensions of Geriatric Frailty: The MacArthur Study of Successful Aging
Catherine A. Sarkisian MD MSPH Tara L. Gruenewald PhD MPH W. John Boscardin PhD Teresa E. Seeman PhD 《Journal of the American Geriatrics Society》2008,56(12):2292-2297
OBJECTIVES: To identify frailty subdimensions. DESIGN: Longitudinal cohort (MacArthur Study). SETTING: Three U.S. urban centers. PARTICIPANTS: One thousand one hundred eighteen high‐functioning subjects aged 70 to 79 in 1988. MEASUREMENTS: Participants with three or more of five Cardiovascular Health Study (CHS) frailty criteria (weight loss, weak grip, exhaustion, slow gait, and low physical activity) in 1991 were classified as having the CHS frailty phenotype. To identify frailty subdimensions, factor analysis was conducted using the CHS variables and an expanded set including the CHS variables, cognitive impairment, interleukin‐6 (IL‐6), C‐reactive protein (CRP), subjective weakness, and anorexia. Participants with four or more of 10 criteria were classified as having an expanded frailty phenotype. Predictive validity of each identified frailty subdimension was assessed using regression models for 4‐year disability and 9‐year mortality. RESULTS: Two subdimensions of the CHS phenotype and four subdimensions of the expanded frailty phenotype were identified. Cognitive function was consistently part of a subdimension including slower gait, weaker grip, and lower physical activity. The CHS subdimension of slower gait, weaker grip, and lower physical activity predicted disability (adjusted odds ratio (AOR)=1.7, 95% confidence interval (CI)=1.3–2.2) and mortality (AOR=1.5, 95% CI=1.3–1.8). Subdimensions of the expanded model with predictive validity were higher IL‐6 and CRP (AOR=1.2 for mortality); slower gait, weaker grip, lower physical activity, and lower cognitive function (AOR=1.8 for disability; AOR=1.5 for mortality), and anorexia and weight loss (AOR=1.2 for disability). CONCLUSION: This study provides preliminary empirical support for subdimensions of geriatric frailty, suggesting that pathways to frailty differ and that subdimension‐adapted care might enhance care of frail seniors. 相似文献
52.
Clinicians' perceptions of the problem of antimicrobial resistance in health care facilities 总被引:4,自引:0,他引:4
Giblin TB Sinkowitz-Cochran RL Harris PL Jacobs S Liberatore K Palfreyman MA Harrison EI Cardo DM;CDC Campaign to Prevent Antimicrobial Resistance Team 《Archives of internal medicine》2004,164(15):1662-1668
BACKGROUND: Many clinicians do not comply with guidelines regarding antimicrobial resistance (AR). In response, the Centers for Disease Control and Prevention developed a national Campaign to Prevent Antimicrobial Resistance in Healthcare Settings that presents 4 strategies and 12 evidence-based steps. METHODS: To assess clinicians' perceptions of AR, barriers and facilitators to preventing AR, and how best to reach clinicians, a questionnaire and 4 focus groups were conducted after presentation of the Campaign at 4 Pittsburgh Regional Healthcare Initiative hospitals. RESULTS: One hundred seventeen clinicians completed the questionnaire; 28 participated in the focus groups. Clinicians were significantly more likely to perceive that AR was a problem nationally than in their own institution (95% vs 77%; P<.001) or practice (95% vs 65%; P =.002), consistent with focus group results (93% nationally vs 46% institution or practice). The 3 Campaign steps with the most barriers to implementation were "Treat infection, not colonization" (35%), "Stop treatment when infection is cured or unlikely" (35%), and "Practice antimicrobial control" (33%). Clinicians in the focus groups cited the additional barriers of the health care culture, lack of knowledge, and the nursing shortage; facilitators included education, information technology, and consults. Computer programs, posters, and local data were suggested for reaching clinicians about AR. CONCLUSIONS: Clinicians perceive AR to be a complex national problem but less relevant to their own institution or practice. Providing clinicians with information and steps for preventing AR, as in the Campaign, may affect their perceptions of the problem and motivate them to take actions to ensure patient safety. 相似文献
53.
Severe hypoglycaemia in 1076 adult patients with type 1 diabetes: influence of risk markers and selection 总被引:1,自引:0,他引:1
Pedersen-Bjergaard U Pramming S Heller SR Wallace TM Rasmussen AK Jørgensen HV Matthews DR Hougaard P Thorsteinsson B 《Diabetes/metabolism research and reviews》2004,20(6):479-486
BACKGROUND: Differences between studies in rates of severe hypoglycaemia in type 1 diabetic cohorts are common and poorly understood. The purpose of this study was to assess the frequency of severe hypoglycaemia in unselected patients treated in different secondary care centres and to evaluate the influence of risk markers, clinical setting and selection. METHODS: Cross-sectional Danish-British multicentre survey of 1076 consecutive adult patients with clinical type 1 diabetes who completed a detailed questionnaire on hypoglycaemia and related issues. Key variable was the self-reported rate of severe hypoglycaemia during the preceding year. RESULTS: The overall rate of severe hypoglycaemia in the preceding year was 1.3 episodes/patient-year and episodes were reported by 36.7% of subjects. The distribution was highly skewed with 5% of subjects accounting for 54% of all episodes. There were no significant differences between countries or centres. Reduced hypoglycaemia awareness, peripheral neuropathy and smoking were the only significant risk markers of severe hypoglycaemia in a stepwise multivariate analysis. In a subgroup selected to be similar to the Diabetes Control and Complications Trial (DCCT) cohort, the rate of severe hypoglycaemia was 0.35 episodes/patient-year and only retinopathy was a significant risk marker together with state of awareness. CONCLUSION: Severe hypoglycaemia remains a significant clinical problem in type 1 diabetes. The rate of severe hypoglycaemia and the influence of risk markers are very sensitive to selection and differences in rates between centres or studies seem to disappear after correction for differences in clinical characteristics. Smoking is a novel overall risk marker of severe hypoglycaemia. 相似文献
54.
Berhe N Medhin G Erko B Smith T Gedamu S Bereded D Moore R Habte E Redda A Gebre-Michael T Gundersen SG 《Acta tropica》2004,92(3):205-212
Examination of stool specimens by Kato-Katz (K-K) thick smears is the standard method recommended by the WHO for field diagnosis of intestinal schistosomiasis. However, there is increasing concern that this technique has low diagnostic sensitivity. In 326 study subjects, we compared the diagnostic yield of examining one, three or five Kato-Katz thick smears prepared from one stool specimen using 41.7 mg templates. In a subset of 169 subjects who had no demonstrable Schistosoma mansoni eggs in their first three Kato-Katz thick smears, we assessed the comparative advantage of examining an additional three Kato-Katz thick smears from another stool specimen, taken four weeks later, to that of cumulative yield obtained by examining all five Kato-Katz thick smears derived from the first stool specimen. For all helminth infections, single Kato-Katz thick smear-based prevalence estimates were significantly lower than those obtained from triplet or quintet Kato-Katz thick smears. Prevalence of S. mansoni infection based on single, triplet and quintet Kato-Katz thick smears from one stool specimen were 31.3%, 45.7% and 52.1%, respectively. Prevalence estimate of S. mansoni based on quintet Kato-Katz thick smears from the first day stool specimens was not different from cumulative estimate obtained with two triplet Kato-Katz thick smears from two stool specimens, 52.1% and 52.8%, respectively. In conclusion, either examination of quintet Kato-Katz thick smears from one stool specimen using 41.7 mg template or initial triplet Kato-Katz thick smears from one stool specimen, and if these are negative, followed by examination of additional triplet Kato-Katz thick smears from subsequent day stool specimen can adequately assess individuals for infection status with S. mansoni. 相似文献
55.
56.
57.
Anil Rana Jimi Marin Alex Monika Chauhan Gaurav Joshi Raj Kumar 《Medicinal chemistry research》2015,24(3):903-920
Past few decades have witnessed the dawn of new diseases in which cancer is a major problem and the race ensued to eradicate cancer by charting out various effective therapeutic regimens. Circumventing resistance issues and combating the toxicity and selectivity problems are matter-of-concern in cancer treatment. Persistent failure to ensure complete remission and eradication of cancer instigated the researchers to exploit the strategies of combining pharmacophores as targeted therapeutic agents. Momentous improvement in the pharmacokinetic as well as pharmacodynamic profile resulting in the enhancement of bioavailability was seen with the introduction of these pharmacophores. The scope of molecular hybridization can be clearly exemplified through the US-FDA approved estramustine and others such as CUDC-101, CBLC-137, PLX3397, E-3810, and CUDC-907 that are currently in different phases of clinical trials. This review seeks to highlight and discuss anti-proliferative activity of some important hybrid, dual, and multi-targeted pharmacophores reported to date along with their designs, structure activity relationships, scope, and limitations. Further, an emphasis has been made to summarize US-FDA approved as well as drugs currently undergoing clinical trials of anticancer drug development. 相似文献
58.
59.
Shira H. Fischer MD PhD Regina A. Shih PhD Tara L. McMullen PhD Maria O. Edelen PhD Sangeeta C. Ahluwalia PhD Emily K. Chen PhD Sarah E. Dalton MA Susan Paddock PhD Anthony Rodriguez PhD Debra Saliba MD MPH AGSF Stella Mandl BSW BSN RN Teresa Mota BSN RN Advisory Group on Medication Reconciliation in PAC 《Journal of the American Geriatrics Society》2022,70(4):1047-1056
60.