High accuracy in automatic detection of atrial fibrillation for Holter monitoring

Atrial fibrillation (AF) has been considered as a growing epidemiological problem in the world, with a substantial impact on morbidity and mortality. Ambulatory electrocardiography (e.g., Holter) monitoring is commonly used for AF diagnosis and therapy and the automated detection of AF is of great significance due to the vast amount of information provided. This study presents a combined method to achieve high accuracy in AF detection. Firstly, we detected the suspected transitions between AF and sinus rhythm using the delta RR interval distribution difference curve, which were then classified by a combination analysis of P wave and RR interval. The MIT-BIH AF database was used for algorithm validation and a high sensitivity and a high specificity (98.2% and 97.5%, respectively) were achieved. Further, we developed a dataset of 24-h paroxysmal AF Holter recordings (n=45) to evaluate the performance in clinical practice, which yielded satisfactory accuracy (sensitivity=96.3%, specificity=96.8%).     

蛭类吸血特性和分子进化初探

将云南牛蛭（P.yunnanensis）水蛭素基因的克隆测序结果与前人所报导的20个抗凝血因子和相对应的种属线粒体细胞色素氧化酶片段I（COI）比对,构建NJ进化树,以对吸血蛭类的分子进化机制及舌蛭科和医蛭亚目吸血特性的起源进行探究．结果表明：蛭类凝血抑制因子按相似性可分为以Hirudin家族蛋白和Antistasin蛋白家族为基础的两大类群;吻蛭目和无吻蛭目的吸血特性虽然起源不同,但可能共有一套相同位点的遗传基因．     

二氧化钛薄膜光催化降解酸性品红

采用溶胶－凝胶法在玻璃表面制得TiO2(锐钛型）薄膜，研究了以254nm的紫外线为光源，酸性品红（AF）在TiO2薄膜上的光催化降解初始速率与溶液初始浓度、初始pH值及外加氧化剂H2O2的关系。结果表明，AF的光催化降解行为采用Langmuir-Hinshelwood(L-H)模型来解释，利用TiO2薄膜作为光催化剂光降有机物AF具有较好的应用前景。     

Non-pulmonary vein foci induced before and after pulmonary vein isolation in patients undergoing ablation therapy for paroxysmal atrial fibrillation: incidence and clinical outcome

Objective

To evaluate the incidence and clinical outcome of adenosine triphosphate (ATP) plus isoproterenol (ISP)-induced non-pulmonary vein (PV) foci before and after circumferential PV isolation (CPVI) during index ablation in patients with paroxysmal atrial fibrillation (PAF).

Methods

In 80 consecutive patients undergoing catheter ablation for drug-refractory, symptomatic PAF at our hospital from April 2010 to January 2011, atrial fibrillation (AF) was provoked with ATP (20 mg) and ISP (20 μg/min) administration before and after CPVI. The spontaneous initiation of AF was mapped and recorded.

Results

Before ablation, AF mostly originating from PVs (PV vs. non-PV, 36/70 vs. 3/70; P<0.01) was induced in 39 patients with sinus rhythm. CPVI significantly suppressed AF inducibility; however, more non-PV foci were provoked (post-CPVI vs. pre-CPVI, 13/76 vs. 3/70; P=0.016). Patients with pre- and post-CPVI induced AF (n=49) were divided according to non-PV foci being induced (group N, n=17) or not (group P, n=32). After mean (19.2±8.2) months follow-up, 88.2% (15/17) and 65.6% (21/32) of patients in groups N and P, respectively, were free from AF recurrence (P=0.088).

Conclusions

ATP+ISP administration effectively provokes non-PV foci, especially after CPVI in PAF patients. Although in this study difference did not achieve statistical significance, supplementary ablation targeting non-PV foci might benefit clinical outcome.     

Segmental radiofrequency ablation of pulmonary vein ostia for patients with refractory paroxysmal atrial fibrillation using multi-slice spiral computed tomography guidance

INTRODUCTION Pulmonary veins(PV)may play an importantrole in both the initiation and maintenance of parox-ysmal atrial fibrillation(AF)(Fynn and Kalman,2004).Curative treatment of patients with paroxys-mal AF is possible by radiofrequency ablation,mak-ing segmental or linear lesions around the ostia ofPVs using a3-dimentional mapping system(Carto)(Pappone et al.,2000;2001;Oral et al.,2003).Multi-slice spiral computed tomography(MSCT)could generate a3-dimentional image of left atrium…     

Research on the improved cooperative cellular system capacity

Recently, the multi-hop cellular networks have been widely studied in order to enhance the cell performances such as the cell capacity. While most of these works merely use the multi-hop methods instead of direct transmission without considering the co-channel inter-cell interference, signal transmission mode and the effects of the number of antennas. With the consideration of above important elements, this paper proposed an improved cellular system with multi-relay amplifies-and-forward (AF) cooperative transmission scheme and the corresponding capacity expression is derived under the corresponding environment. By using the potential space diversity and selecting relays based on maximizing the capacity, the cellular system capacity can be improved effectively. The simulation results show that with the assistance of optimal selected relays, the improved cooperative cellular system capacity with multi-relay AF transmission scheme performs better than single-hop cellular system.     

Risk analysis of new oral anticoagulants for gastrointestinal bleeding and intracranial hemorrhage in atrial fibrillation patients: a systematic review and network meta-analysis

Background

Antithrombotic therapy using new oral anticoagulants (NOACs) in patients with atrial fibrillation (AF) has been generally shown to have a favorable risk-benefit profile. Since there has been dispute about the risks of gastrointestinal bleeding (GIB) and intracranial hemorrhage (ICH), we sought to conduct a systematic review and network meta-analysis using Bayesian inference to analyze the risks of GIB and ICH in AF patients taking NOACs.

Methods

We analyzed data from 20 randomized controlled trials of 91 671 AF patients receiving anticoagulants, antiplatelet drugs, or placebo. Bayesian network meta-analysis of two different evidence networks was performed using a binomial likelihood model, based on a network in which different agents (and doses) were treated as separate nodes. Odds ratios (ORs) and 95% confidence intervals (CIs) were modeled using Markov chain Monte Carlo methods.

Results

Indirect comparisons with the Bayesian model confirmed that aspirin+clopidogrel significantly increased the risk of GIB in AF patients compared to the placebo (OR 0.33, 95% CI 0.01–0.92). Warfarin was identified as greatly increasing the risk of ICH compared to edoxaban 30 mg (OR 3.42, 95% CI 1.22–7.24) and dabigatran 110 mg (OR 3.56, 95% CI 1.10–8.45). We further ranked the NOACs for the lowest risk of GIB (apixaban 5 mg) and ICH (apixaban 5 mg, dabigatran 110 mg, and edoxaban 30 mg).

Conclusion

Bayesian network meta-analysis of treatment of nonvalvular AF patients with anticoagulants suggested that NOACs do not increase risks of GIB and/or ICH, compared to each other.

     

Effect of corticosteroids on atrial fibrillation after catheter ablation: a meta-analysis

Objective

The purpose of this meta-analysis was to explore the effect of corticosteroids on atrial fibrillation (AF) following catheter ablation.

Methods

We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials for published articles describing the effect of corticosteroids in preventing AF recurrence after catheter ablation. Data on study and patient were extracted. Risk ratios (RRs) and 95% confidence intervals (CIs) were calculated by use of a random-effect model, and P values of <0.05 were considered significant.

Results

Two randomized controlled trials (RCTs) and three cohort studies involving 846 patients were included in this meta-analysis. Within one month of catheter ablation, corticosteroid use was associated with a declined risk of recurrence of AF in RCT (RR 0.57, 95% CI 0.39 to 0.85, P=0.005), but without significant effect in cohort studies (RR 1.01, 95% CI 0.79 to 1.30, P=0.94). After three months of catheter ablation, corticosteroids did not have a significant effect in the prevention of late recurrence of AF in either RCT (RR 0.78, 95% CI 0.38 to 1.59, P=0.49) or cohort studies (RR 0.96, 95% CI 0.70 to 1.31, P=0.78).

Conclusions

Our meta-analysis suggested that periprocedural administration of corticosteroids of catheter ablation was associated with reduction of early but not late recurrence of AF.

     

基于OTA负反馈放大器的闭环特性研究

基于网络的A参数，利用网络分析法分析了由OTA组成的4种组态负反馈放大器的闭环特性，结果表明：对OTA施加负反馈，闭环放大倍数，闭环输入、输出电阻的改变量，形式上仍为1 AF，这与由传统电压型运放构成的负反馈放大器结论一致。     

Human Anatomy: Let the students tell us how to teach

Anatomy teaching methods have evolved as the medical undergraduate curriculum has modernized. Traditional teaching methods of dissection, prosection, tutorials and lectures are now supplemented by anatomical models and e‐learning. Despite these changes, the preferences of medical students and anatomy faculty towards both traditional and contemporary teaching methods and tools are largely unknown. This study quantified medical student and anatomy faculty opinion on various aspects of anatomical teaching at the Department of Anatomy, University of Bristol, UK. A questionnaire was used to explore the perceived effectiveness of different anatomical teaching methods and tools among anatomy faculty (AF) and medical students in year one (Y1) and year two (Y2). A total of 370 preclinical medical students entered the study (76% response rate). Responses were quantified and intergroup comparisons were made. All students and AF were strongly in favor of access to cadaveric specimens and supported traditional methods of small‐group teaching with medically qualified demonstrators. Other teaching methods, including e‐learning, anatomical models and surgical videos, were considered useful educational tools. In several areas there was disharmony between the opinions of AF and medical students. This study emphasizes the importance of collecting student preferences to optimize teaching methods used in the undergraduate anatomy curriculum. Anat Sci Educ 7: 262–272. © 2013 American Association of Anatomists.     

Concurrent pulmonary thrombosis with systemic embolism: a case report

Based on different mechanisms of blood coagulation, coexistence of venous thromboembolism and arterial thrombosis in a single individual is extremely rare in clinical practice. Both antiplatelet and anticoagulation therapy should be adopted for patients with arteriovenous embolism. Balancing the risk of ischemia and hemorrhage is especially challenging in these patients in order to achieve an optimal clinical benefit. We report on a 55-year-old female with acute pulmonary embolism (PE), subsequently diagnosed as having acute myocardial infarction (AMI) and a cerebral infarction. Examinations had been carried out, excluding potential arteriovenous shunts, cancer, antiphospholipid syndrome and other common hypercoagulable states. A combination of an anticoagulant drug (rivaroxaban, an Xa inhibitor) and an antiplatelet agent (clopidogrel, an ADP receptor inhibitor) was prescribed with a β-blocker and atorvastatin. The embolus was gradually shrunk during the next 10 months, and then it turned back into expanding. During the 16 months’ follow-up, an aneurysm of left ventricular apex was found through an echocardiogram and an angiotensin-converting enzyme inhibitor was administered. We conclude that combined anticoagulation and antiplatelet therapy significantly relieved the symptoms and improved the prognosis in patients suffering from arteriovenous embolism without any major clinical bleeding events.     

三七皂甙、肝素钠和蝮蛇毒纤溶酶组份对凝血系统的作用研究

就三七皂甙（PNS）及与肝素钠、蝮蛇毒纤溶酶组分的复方对纤维蛋白原的凝血酶时间、体内外复钙时间和纤溶激活作用进行了研究,结果表明,三七皂甙能增强肝素的抗凝活性,增加蝮蛇毒纤溶组分的溶纤作用,但无抗凝血酶作用。     

Current progress of computational modeling for guiding clinical atrial fibrillation ablation

Journal of Zhejiang University-SCIENCE B - Atrial fibrillation (AF) is one of the most common arrhythmias, associated with high morbidity, mortality, and healthcare costs, and it places a...     

图书馆文献流通服务场所设置和布局合理性的分析

以西北农林科技大学南校区图书馆为例,详述了其文献流通服务场所、部门的设置和布局特点,说明了合理性、人性化的设置和布局是一个现代图书馆应该具备的的基本形态,亦是形成良好管理的基础。     

Elevated skin autofluorescence is strongly associated with foot ulcers in patients with diabetes: a cross-sectional, observational study of Chinese subjects

Objective  

This study was designed to evaluate the association between skin autofluorescence (AF), an indicator of advanced glycation end-products (AGEs), and foot ulcers in subjects with diabetes.     

Comparison of low-molecular-weight-heparin and unfractionated heparin for acute PTE

INTRODUCTION Acute pulmonary thromboembolism(PTE)is serious pulmonary vascular disease with high mortality.The challenge is to make a correct diagnosiand give appropriate treatment(Nicolaides et al.2001).Effective treatment will decrease morbidityand mortality.This study compares the efficacy,adverse effects and costs of low-molecular-weightheparin(LMWH)and unfractionated heparin(UH).MATERIALS AND METHODS Materialss a or-sis al.,ity ad-ht-).All patients diagnosed as non-massiv…     

谈高校教学实验室“环境管理体系认证”工作的意义与经验体会

本文通过对环境管理体系标准（ISO14001）要求、使用指南和我校教学实验室环境管理体系认证过程的阐述,强调了教学实验室推行环境管理体系的重要性,总结了西北农林科技大学教学实验室环境管理体系认证的经验体会,为长期坚持这项工作打下了良好的基础。     

Anticoagulation therapy in intra-aortic balloon counterpulsation: Does IABP really need anti-coagulation?

INTRODUCTIONTheintra aorticballoonpump(IABP)isthemostwidelyusedofallcirculatoryassistdevicestodayandisroutinelyusedinawiderangeofse riouscardiovascularconditions,rangingfromhe modynamicinstabilityinpatientssufferingfromcomplicationsofacutemyocardialinfarc…     

稀土Sm掺杂PLA/TiO2杂化材料的制备及抗凝血性能测定

以乳酸为原料、辛酸亚锡为催化剂制备聚乳酸(PLA);以PLA、Sm、钛酸四正丁酯(TBT)为原料,采用溶胶凝胶法制备稀土Sm掺杂PLA/TiO2有机无机杂化材料。XPS分析结果显示了Sm的加入。动态凝血时间测定法测定结果表明,Sm的掺杂提高了PLA/TiO2的抗凝血能力,并且在加入量为wt0.6%时效果最佳。