收费全文 | 2759篇 |
免费 | 254篇 |
国内免费 | 10篇 |
耳鼻咽喉 | 17篇 |
儿科学 | 60篇 |
妇产科学 | 35篇 |
基础医学 | 380篇 |
口腔科学 | 91篇 |
临床医学 | 323篇 |
内科学 | 597篇 |
皮肤病学 | 18篇 |
神经病学 | 285篇 |
特种医学 | 206篇 |
外科学 | 305篇 |
综合类 | 73篇 |
预防医学 | 250篇 |
眼科学 | 17篇 |
药学 | 166篇 |
肿瘤学 | 200篇 |
2022年 | 24篇 |
2021年 | 39篇 |
2020年 | 35篇 |
2019年 | 32篇 |
2018年 | 42篇 |
2017年 | 32篇 |
2016年 | 41篇 |
2015年 | 42篇 |
2014年 | 44篇 |
2013年 | 95篇 |
2012年 | 115篇 |
2011年 | 124篇 |
2010年 | 73篇 |
2009年 | 76篇 |
2008年 | 111篇 |
2007年 | 101篇 |
2006年 | 105篇 |
2005年 | 97篇 |
2004年 | 105篇 |
2003年 | 103篇 |
2002年 | 94篇 |
2001年 | 77篇 |
2000年 | 80篇 |
1999年 | 92篇 |
1998年 | 61篇 |
1997年 | 59篇 |
1996年 | 54篇 |
1995年 | 48篇 |
1994年 | 46篇 |
1993年 | 38篇 |
1992年 | 68篇 |
1991年 | 65篇 |
1990年 | 59篇 |
1989年 | 60篇 |
1988年 | 49篇 |
1987年 | 53篇 |
1986年 | 57篇 |
1985年 | 65篇 |
1984年 | 28篇 |
1983年 | 26篇 |
1981年 | 21篇 |
1979年 | 26篇 |
1976年 | 20篇 |
1975年 | 20篇 |
1974年 | 26篇 |
1973年 | 21篇 |
1972年 | 24篇 |
1971年 | 21篇 |
1968年 | 20篇 |
1966年 | 20篇 |
Purpose
Pulmonary edema (PE) is associated with fluid accumulation in the lungs. Device-based impedance measurements have been used to detect fluid overload prior to hospitalization. However, studies have reported a high false positive rate (FPR). The objective of this study was to develop and test a new multivector impedance-based algorithm that reliably tracks PE clinical events.Methods
We enrolled patients with implanted CRT-Ds in 23 US centers within 2 weeks of device implant. Six-vector impedance data was collected automatically by the CRT-Ds every 30 min during emergency department visits/hospitalizations and every 2 h at all other times. Detection algorithms for cardiac resynchronization therapy defibrillator (CRT-D) and implantable cardiac defibrillator (ICD) devices were developed using those impedance vectors that would be available in corresponding devices and retrospectively evaluated.Results
There were 75 patients (69 % male), mean age 66?±?12 years, with a LVEF of 23?±?6 % and QRS of 149?±?25 ms. Twenty-one major clinical events occurred over 8.2?±?2.6 months of follow-up time. CRT-D vector combinations resulted in a sensitivity of 71.4 % (95 % confidence interval 47.8–88.7) and a FPR of 0.56 (0.30–0.94) false positives per patient-year (FPs/pt-yr); ICD vector combinations resulted in a sensitivity of 61.9 % (38.4–81.9) and a FPR of 0.63 (0.36–0.90) FPs/pt-yr. In comparison, the single-vector RVCoil-Can implementation of this algorithm resulted in a sensitivity of 57.1 % (34.0–78.2) and a FPR of 0.74 (0.44–1.12) FPs/pt-yr.Conclusions
This multivector impedance algorithm was effective in tracking PE clinical events in this patient population. Additional studies are needed to prospectively evaluate the performance of this algorithm in a larger population. 相似文献Methods: Results from individual interviews and focus group discussions with 246 service users who had experienced alcohol and drug treatment in Bulgaria, Greece, Italy, Poland, Slovakia, Slovenia, Spain and Scotland are described. Thematic analysis was used to interpret the data.
Results: The study identified a number of consistent facilitating factors and barriers across all eight European countries, despite different health care systems. The results suggest that five main factors were implicated in the help-seeking behaviour of the service users interviewed. These were: information, service organisation, staff attitudes, significant others and personal disposition. All these factors could be viewed as both facilitators and barriers.
Conclusions: To enhance access to alcohol and drug treatment, local, non-stigmatising and available services are required alongside support from significant others which should increase motivation and skills of potential service users. 相似文献