收费全文 | 35263篇 |
免费 | 2225篇 |
国内免费 | 187篇 |
耳鼻咽喉 | 140篇 |
儿科学 | 878篇 |
妇产科学 | 1083篇 |
基础医学 | 2269篇 |
口腔科学 | 476篇 |
临床医学 | 4959篇 |
内科学 | 5588篇 |
皮肤病学 | 226篇 |
神经病学 | 2056篇 |
特种医学 | 992篇 |
外科学 | 4488篇 |
综合类 | 1232篇 |
现状与发展 | 1篇 |
一般理论 | 7篇 |
预防医学 | 9650篇 |
眼科学 | 296篇 |
药学 | 1564篇 |
17篇 | |
中国医学 | 91篇 |
肿瘤学 | 1662篇 |
2024年 | 60篇 |
2023年 | 2052篇 |
2022年 | 2805篇 |
2021年 | 2704篇 |
2020年 | 3012篇 |
2019年 | 1772篇 |
2018年 | 1772篇 |
2017年 | 1782篇 |
2016年 | 1736篇 |
2015年 | 1624篇 |
2014年 | 2833篇 |
2013年 | 2187篇 |
2012年 | 1579篇 |
2011年 | 1263篇 |
2010年 | 1624篇 |
2009年 | 1490篇 |
2008年 | 845篇 |
2007年 | 840篇 |
2006年 | 728篇 |
2005年 | 540篇 |
2004年 | 428篇 |
2003年 | 465篇 |
2002年 | 468篇 |
2001年 | 374篇 |
2000年 | 334篇 |
1999年 | 348篇 |
1998年 | 253篇 |
1997年 | 208篇 |
1996年 | 226篇 |
1995年 | 190篇 |
1994年 | 136篇 |
1993年 | 90篇 |
1992年 | 110篇 |
1991年 | 96篇 |
1990年 | 96篇 |
1989年 | 94篇 |
1988年 | 113篇 |
1987年 | 83篇 |
1986年 | 91篇 |
1985年 | 21篇 |
1984年 | 39篇 |
1983年 | 23篇 |
1982年 | 33篇 |
1981年 | 30篇 |
1980年 | 26篇 |
1979年 | 5篇 |
1978年 | 10篇 |
1977年 | 17篇 |
1976年 | 14篇 |
1973年 | 4篇 |
Background and objective
Pressure ulcer (PU) is one of the important and frequent complications of hospitalization, associated with high treatment costs. The present study was conducted to determine the incidence of PU and its direct treatment costs for patients in intensive care unit (ICU) in Iran.Material and methods
In this retrospective study, medical records of 643 discharged patients from ICU of two selected hospitals were examined. The demographic and clinical data of all patients and data of resources and services usage for patients with PU were extracted through their records. Data analysis was done using logistic regression tests in SPSS 22 software. The cost of PU treatment was calculated for each grade of ulcer.Results
The findings showed that 8.9% of patients developed PU during their stay in ICU. Muscular paralysis (OR?=?5.1), length of stay in ICU (OR?=?4.0), diabetes (OR?=?3.5) age (OR?=?2.9), smoking (OR?=?2.1) and trauma (OR?=?1.4) were the most important risk factors of PU. The average cost of PU treatment varied from USD 12 for grade I PU to USD 66?834 for grade IV PUs. The total treatment costs for all studied patients with PU was estimated at USD 519?991.Conclusion
The cost of PU treatment is significant. Since the preventive measures are more cost-effective than therapeutic measures, therefore, effective preventive interventions are recommended. 相似文献Ressults show that opportunities for improving O&M include; operation of public toilets is a source of livelihood; operators are knowledgeable on occupational risks, and the community is involvedin sanitation activities. Barriers to effective O&M include; high operation costs, failure to break even and a lack of investments in occupational health Therefore, there is need to recognise the significance of public toilets as a viable alternative to open defecation in areas where ownership of private sanitation facilities is difficult. Failure to observe the health and safety of toilet operators may further compromise O&M. 相似文献
Background and aims
It is not known whether non alcoholic fatty liver disease (NAFLD) is a risk factor for diabetes in non obese, non centrally-obese subjects. Our aim was to investigate relationships between fatty liver, insulin resistance and a biomarker score for liver fibrosis with incident diabetes at follow up, in subjects who were neither obese nor centrally-obese.Methods and results
As many as 70,303 subjects with a body mass index (BMI) < 25 kg/m2 and without diabetes were followed up for a maximum of 7.9 years. At baseline, fatty liver was identified by liver ultrasound, insulin resistance (IR) by homeostatic model assessment of insulin resistance (HOMA-IR) ≥2.0, and central obesity by waist circumference (waist circumference ≥90 cm (men) and ≥85 cm (women). The Fibrosis-4 (FIB-4 score) was used to estimate extent of liver fibrosis. Cox proportional hazards models adjusted for confounders were used to estimate hazard ratios (aHRs) for incident diabetes. As many as 852 incident cases of diabetes occurred during follow up (median [IQR] 3.71 [2.03] years). Mean ± SD BMI was 22.8 ± 1.8 and 21.7 ± 2.0 kg/m2 in subjects with and without diabetes at follow up. In subjects without central obesity and with fatty liver, aHRs (95% CI) for incident diabetes at follow up were 2.17 (1.56, 3.03) for men, and 2.86 (1.50,5.46) for women. Similar aHRs for incident diabetes occurred with fatty liver, IR and the highest quartile of FIB-4 combined, in men; and there was a non significant trend toward increased risk in women.Conclusions
In normal weight, non-centrally obese subjects NAFLD is an independent risk factor for incident diabetes. 相似文献Areas covered: Approximately 10–45% of patients undergoing head-and-neck cancers surgery develop SSIs. SSIs can lead to delayed wound healing, increased morbidity and mortality as well as costs. Consequently, SSIs need to be avoided where possible, as even the surgery itself impacts on patients’ subsequent activities and their quality of life, which is exacerbated by SSIs. Several risk factors for SSIs need to be considered to reduce future rates, and care is also needed in the selection and duration of antibiotic prophylaxis.
Expert commentary: Head and neck surgeons should give personalized care especially to patients at high risk of SSIs. Such patients include those who have had chemoradiotherapy and need reconstructive surgery, and patients from lower and middle-income countries and from poorer communities in high income countries, who often have high levels of co-morbidity because of resource constraints. 相似文献