全文获取类型
收费全文 | 2653篇 |
免费 | 166篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 30篇 |
儿科学 | 57篇 |
妇产科学 | 133篇 |
基础医学 | 255篇 |
口腔科学 | 72篇 |
临床医学 | 215篇 |
内科学 | 560篇 |
皮肤病学 | 44篇 |
神经病学 | 185篇 |
特种医学 | 110篇 |
外国民族医学 | 3篇 |
外科学 | 479篇 |
综合类 | 34篇 |
一般理论 | 3篇 |
预防医学 | 121篇 |
眼科学 | 116篇 |
药学 | 172篇 |
中国医学 | 3篇 |
肿瘤学 | 241篇 |
出版年
2024年 | 3篇 |
2023年 | 27篇 |
2022年 | 56篇 |
2021年 | 111篇 |
2020年 | 81篇 |
2019年 | 112篇 |
2018年 | 170篇 |
2017年 | 112篇 |
2016年 | 88篇 |
2015年 | 94篇 |
2014年 | 126篇 |
2013年 | 152篇 |
2012年 | 229篇 |
2011年 | 227篇 |
2010年 | 138篇 |
2009年 | 94篇 |
2008年 | 163篇 |
2007年 | 155篇 |
2006年 | 126篇 |
2005年 | 120篇 |
2004年 | 108篇 |
2003年 | 117篇 |
2002年 | 106篇 |
2001年 | 11篇 |
2000年 | 7篇 |
1999年 | 7篇 |
1998年 | 10篇 |
1997年 | 8篇 |
1996年 | 12篇 |
1995年 | 16篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 5篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1975年 | 4篇 |
1969年 | 1篇 |
排序方式: 共有2833条查询结果,搜索用时 15 毫秒
61.
62.
63.
Ali AY Safwat T Onyemelukwe G Otaibi MA Amir AA Nawas YN Aouina H Afif MH Bolliger CT 《Respiration; international review of thoracic diseases》2012,83(5):423-432
Despite the abundance of scientific evidence confirming the health consequences of smoking and other forms of tobacco use, the tobacco epidemic remains an important public health problem and by 2030 it is predicted that more than 80% of tobacco deaths will be in developing countries. In Africa and the Middle East, many local factors contribute to the initiation and maintenance of tobacco use. Although efforts to reduce the mortality and morbidity associated with smoking and tobacco dependence are underway, there is a need for guidance on how to utilize appropriate tobacco control policies and psychology- and pharmacology-based therapies to counter tobacco dependence as recommended by the Framework Convention on Tobacco Control (FCTC). A group of tobacco cessation experts from public health services and/or academic institutions in Africa and the Middle East participated in a series of four meetings held in Cairo, Cape Town, and Dubai between May 2008 and February 2011 to develop a draft guideline tailored to their region. This article provides the background to the development of this draft smoking cessation guideline and discusses how the recommendations can be implemented and progress monitored to promote both primary prevention and cessation of tobacco use within our countries. The draft guideline for Africa and the Middle East provides an important resource in combating the devastating effects of tobacco use in these regions which can be further localized through engagement with local stakeholders in the countries of the region. 相似文献
64.
Ahmed TA Atary JZ Wolterbeek R Hasan-Ali H Abdel-Kader SS Schalij MJ Jukema JW 《Journal of interventional cardiology》2012,25(1):1-9
Background: The benefits of early abciximab administration and thrombus aspiration in ST elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PPCI) have previously been elaborated. However, whether there is an adjunctive effect of thrombus aspiration among STEMI patients, with angiographic evidence of thrombus, receiving early prehospital abciximab remains unclear. Methods: In the context of a fixed protocol for PPCI, 158 consecutive patients with STEMI were enrolled, in whom abciximab was started early before hospital arrival (in‐ambulance); 79 patients who had PPCI with thrombus aspiration (thrombectomy‐facilitated PCI group), were compared to 79 who had PPCI without thrombus aspiration (conventional PCI group) in a prospective nonrandomized study. The primary end‐point was complete ST‐segment resolution within 90 minutes. Secondary end points included distal embolization, enzymatic infarct size as well as left ventricular ejection fraction (LVEF) assessed by gated single‐photon emission computed tomography. Major adverse cardiac events (MACEs) were evaluated up to 12 months. Results: Both groups were comparable for baseline characteristics. ST‐segment resolution was significantly higher in the thrombectomy‐facilitated group (P = 0.002), and multivariate analysis identified thrombectomy as an independent predictor of ST‐segment resolution (OR = 9.4, 95% CI = 2.6–33.5, P = 0.001). Distal embolization was higher in the conventional PCI group among patients with higher thrombus grades. No difference was observed between both groups in infarct size assessed by peak creatine kinase (p = 0.689) and peak Tn‐T levels (P = 0.435). Also, the LVEF at 3 months was similar (P = 0.957). At 12 month clinical follow‐up, thrombus aspiration was, however, associated with reduced all‐cause mortality (log‐rank p = 0.032). Conclusion: Among STEMI patients treated with PPCI and in‐ambulance abciximab, it appears that a selective strategy of thrombus aspiration still has additive benefit. (J Interven Cardiol 2012;25:1–9) 相似文献
65.
AIM:To investigate a dual labeling technique,which would enable real-time monitoring of transplanted embryonic stem cell(ESC) kinetics,as well as long-term tracking.METHODS:Liver damage was induced in C57/BL6 male mice(n = 40) by acetaminophen(APAP) 300 mg/kg administered intraperitoneally.Green fluorescence protein(GFP) positive C57/BL6 mouse ESCs were stained with the near-infrared fluorescent lipophilic tracer 1,1-dioctadecyl-3,3,3,3-tetramethylindotricarbocyanine iodide(DiR) immediately before transplantationinto the spleen.Each of the animals in the cell therapy group(n = 20) received 5 × 10 6 ESCs 4 h following treatment with APAP.The control group(n = 20) received the vehicle only.The distribution and dynamics of the cells were monitored in real-time with the IVIS Lumina-2 at 30 min post transplantation,then at 3,12,24,48 and 72 h,and after one and 2 wk.Immunohistochemical examination of liver tissue was used to identify expression of GFP and albumin.Plasma alanine aminotransferase(ALT) was measured as an indication of liver damage.RESULTS:DiR-stained ESCs were easily tracked with the IVIS using the indocyanine green filter due to its high background passband with minimal background autofluorescence.The transplanted cells were confined inside the spleen at 30 min post-transplantation,gradually moved into the splenic vein,and were detectable in parts of the liver at the 3 h time-point.Within 24 h of transplantation,homing of almost 90% of cells was confirmed in the liver.On day three,however,the DiR signal started to fade out,and ex vivo IVIS imaging of different organs allowed signal detection at time-points when the signal could not be detected by in vivo imaging,and confirmed that the highest photon emission was in the liver(P 0.0001).At 2 wk,the DiRsignal was no longer detectable in vivo ;however,immunohistochemistry analysis of constitutively-expressed GFP was used to provide an insight into the distribution of the cells.GFP +ve cells were detected in tissue sections resembling hepatocytes and were dispersed throughout the hepatic parenchyma,with the presence of a larger number of GFP +ve cells incorporated within the sinusoidal endothelial lining.Very faint albumin expression was detected in the transplanted GFP +ve cells at 72 h;however at 2 wk,few cells that were positive for GFP were also strongly positive for albumin.There was a significant improvement in serum levels of ALT,albumin and bilirubin in both groups at 2 wk when compared with the 72 h time-point.In the cell therapy group,serum ALT was significantly(P = 0.016) lower and albumin(P = 0.009) was significantly higher when compared with the control group at the 2 wk time-point;however there was no difference in mortality between the two groups.CONCLUSION:Dual labeling is an easy to use and cheap method for longitudinal monitoring of distribution,survival and engraftment of transplanted cells,and could be used for cell therapy models. 相似文献
66.
67.
Dima Youssef Beth Bailey Antwan Atia Adel El‐Abbassi Todd Manning Alan N Peiris 《Geriatrics & Gerontology International》2012,12(3):475-480
Aim: Vitamin D deficiency is a global health issue associated with increased health‐care costs, and could play a role in the pathogenesis and management of inflammatory bowel disease. Prior studies show a high prevalence of vitamin D deficiency in veterans with inflammatory bowel disease. We aimed to examine the outcome differences in patients with inflammatory bowel disease, comparing treatment with ergocalciferol to cholecalciferol. Methods: A retrospective review of electronic medical records of patients with inflammatory bowel disease at a Veterans Affairs Medical Facility in the Southeastern United States was carried out. Those with at least one serum 25(OH) vitamin D level were included. Initial and follow‐up vitamin D values were recorded. The type of vitamin D supplementation, whether cholecalciferol or ergocalciferol, was documented. Costs in the year after measurement of vitamin D were divided into separate inpatient and outpatient categories. Results: Veterans (n = 108) with ulcerative colitis or Crohn's disease and an available 25(OH) vitamin D level were studied. There were differences in follow‐up vitamin D levels; those who received weekly ergocalciferol had higher subsequent levels than those who received cholecalciferol, especially at a second follow up, although differences did not achieve statistical significance. However, those who received vitamin D3 were less likely to use laboratory, pharmacy, radiology and fee‐based services, and had lower laboratory and pharmacy costs. Conclusions: Our data suggest that cholecalciferol replacement might improve outcomes to a greater extent than ergocalciferol, and might be better in limiting health‐care costs and expenses in patients with inflammatory bowel disease. Geriatr Gerontol Int 2012; 12: 475–480. 相似文献
68.
69.
Adil Ouzzane Pierre Colin Tarek P. Ghoneim Marc Zerbib Alexandre De La Taille François Audenet Fabien Saint Nicolas Hoarau Emilie Adam Marie Dominique Azemar Henri Bensadoun Luc Cormier Olivier Cussenot Alain Houlgatte Gilles Karsenty Charlotte Maurin François Xavier Nouhaud Véronique Phe Thomas Polguer Mathieu Roumiguié Alain Ruffion Morgan Rouprêt 《World journal of urology》2013,31(1):189-197
Purpose
Prognostic impact of lymphadenectomy during radical nephroureterectomy (RNU) for urothelial carcinoma of the upper urinary tract (UTUC) is controversial. Our aim was to assess the impact of lymph node status (LNS) on survival in patients treated by RNU.Methods
In our multi-institutional, retrospective database, 714 patients with non-metastatic UTUC had undergone RNU between 1995 and 2010. LNS was tested as prognostic factor for survivals through univariate and multivariable Cox regression analysis.Results
Median age was 70 years [interquartile range (IQR), 60–75] with median follow-up of 27 months (IQR, 10–50). Overall, lymphadenectomy was performed in 254 patients (35.5 %). Among these patients, 204 (80 %) had negative lymph nodes (pN0) and 50 (20 %) had positive lymph nodes (pN1/2). The 5-year cancer-specific survival (CSS) was 81 % [95 % confidence interval (CI), 73–88 %] for pN0 patients, 85 % (95 % CI, 80–90 %) for pNx patients and 47 % (95 % CI, 24–69 %) for pN1/2 patients (p < 0.001). Metastasis-free survival (MFS) and overall survival (OS) rates were significantly lower in pN1/2 patients than in pN0 and pNx patients (p < 0.05). On multivariable analysis, LNS did not appear as an independent prognostic factor for CSS, OS or MFS (p > 0.05). In case of lymph node involvement, extra-nodal extension was marginally associated with worse CSS (log rank p = 0.07). The retrospective design was the main limitation.Conclusion
LNS is helpful for survival stratification in patients treated with RNU for UTUC. However, LNS did not appear as an independent predictor of survival in this retrospective series and needs to be investigated in a large multicentre, prospective evaluation. 相似文献70.
Patrick Sadoghi Birgit Lohberger Birgit Aigner Heike Kaltenegger Jörg Friesenbichler Matthias Wolf Tarek Sununu Andreas Leithner Patrick Vavken 《Journal of orthopaedic research》2013,31(8):1249-1253
To assess the in vitro effect of platelet‐rich plasma (PRP) on biological activity of the human rotator cuff fibroblasts and to describe the optimal dose‐response to maximize cellular stimulation while reducing potential risk. Rotator cuff (RC) fibroblasts of n = 6 patients (mean age of 65.2 years) undergoing arthroscopic cuff tear reconstruction were cultured in vitro for 21 days and stimulated with PRP in three different concentrations (1‐, 5‐, and 10‐fold). Samples were obtained for DNA and GAG measurement at 1, 7, 14, and 21 days. The biological outcomes were regressed on the PRP concentration. The application of PRP significantly influenced the fibroblast proliferation and activity of the human rotator cuff with elevated glycosaminoglycan (GAG) and DNA levels. The dosage of PRP had the significantly highest impact on this proliferation using a onefold or fivefold application. PRP has a significant effect on fibroblast proliferation of the human rotator cuff in vitro with an optimal benefit using a onefold or fivefold PRP concentration. This study justifies further in vivo investigations using PRP at the human rotator cuff. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1249–1253, 2013 相似文献