Epilepsy identification based on EEG signal using RQA method

PurposeEpilepsy is one of the most common neurological diseases and its cause is not unequivocal. Thus, additional methods and searches that may help to diagnose the disease are used in the clinical practice. In this study, we tested the possibility of using the Recurrence Quantification Analysis (RQA) method to identify epilepsy and present the analysis of EEG signals of healthy patients and epileptic patients by the RQA method.Materials/methodsThe recordings of signals belong to 13 patients, which were divided into 2 groups: Group A (5 epileptic patients) and Group B (8 healthy patients). In this study Fp1, Fp2, T3 and T4 electrodes were considered in the analysis using the RQA method.ResultsIt is difficult to explore the dynamics of signals by linear methods. In this study, another way of analyzing the dynamics of signals by the RQA method is presented. The RQA method revealed differences in the dynamics between the epileptic and normal signals, which seemed important in an organoleptic way. It was found that the dynamics of epileptic signals is more periodic than normal signals. To confirm the correctness of the statements issued for the RQA data the Principal Component Analysis mapping was applied. This method showed more clearly the differences in the dynamics of both signals.ConclusionsThe RQA method can be used to identify nonlinear biomedical signals such as EEG signals.     

基于倾向性评分匹配和亚群治疗效果模式图队列研究暴露与结局关联的异质性分析

介绍亚群治疗效果模式图（STEPP）的基本原理、应用场景与主要步骤,梳理将其与倾向性评分匹配（PSM）联合应用在队列研究数据中的理论基础,旨在将STEPP应用到暴露与结局风险关联的异质性分析中。通过模拟案例“不同输液导管类型的肿瘤患者发生静脉血栓栓塞（VTE）风险的队列研究”展示如何将PSM与STEPP在队列研究数据中联合应用,得出亚群中经外周置入中心静脉导管组和中心静脉导管组发生VTE的绝对风险值和相对风险值,以及亚群间的异质性分析结果,并对PSM与STEPP联合应用的局限性和研究前景进行讨论,为实际应用提供参考。     

Optimising nearest neighbour information—a simple,efficient sampling strategy for forestry plot imputation using remotely sensed data

The rapid adoption of LiDAR-assisted forest inventory, together with nearest neighbour imputation, has created new challenges for those involved in sample selection. It is not obvious a priori what type of sample will be the most efficient when used with imputation. In this paper we explore a number of sampling approaches, including conventional methods such as stratification, spatial methods based on tessellations, and balanced sampling. We introduce a new approach called nearest centroid (NC) that optimises the survey design by using the distance properties of the sample in the space defined by the auxiliary variables, and examine this and other methods across a range of survey situations and objectives. The NC method is shown to be highly efficient when compared with other methods and is very flexible in the way it can be implemented.     

An analysis of underlying factors for seasonal variation in gonorrhoea in India: A 6-year statistical assessment

Purpose: A statistical assessment of a disease is often necessary before resources can be allocated to any control programme. No literature on seasonal trends of gonorrhoea is available from India. Objectives: The objectives were (1) to determine, if any, seasonal trends were present in India (2) to describe factors contributing to seasonality of gonorrhoea (3) to formulate approaches for gonorrhoea control at the national level. Materials and Methods: Seasonal indices for gonorrhoea were calculated quarterly in terms of a seasonal index between 2005 and 2010. Ratio-to-moving average method was used to determine the seasonal variation. The original data values in the time-series were expressed as percentages of moving averages. Results were also analyzed by second statistical method i.e. seasonal subseries plot. Results: The seasonally adjusted average for culture-positive gonorrhoea cases was highest in the second quarter (128.61%) followed by third quarter (108.48%) while a trough was observed in the first (96.05%) and last quarter (64.85%). The second quarter peak was representative of summer vacations in schools and colleges. Moreover, April is the harvesting month followed by celebrations and social gatherings. Both these factors are associated with increased sexual activity and partner change. A trough in first and last quarter was indicative of festival season and winter leading to less patients reporting to the hospital. Conclusion: The findings highlight the immediate need to strengthen sexual health education among young people in schools and colleges and education on risk-reduction practices especially at crucial points in the calendar year for effective gonorrhoea control.     

Quantitative chemical exchange saturation transfer (qCEST) MRI – omega plot analysis of RF‐spillover‐corrected inverse CEST ratio asymmetry for simultaneous determination of labile proton ratio and exchange rate

Chemical exchange saturation transfer (CEST) MRI is sensitive to labile proton concentration and exchange rate, thus allowing measurement of dilute CEST agent and microenvironmental properties. However, CEST measurement depends not only on the CEST agent properties but also on the experimental conditions. Quantitative CEST (qCEST) analysis has been proposed to address the limitation of the commonly used simplistic CEST‐weighted calculation. Recent research has shown that the concomitant direct RF saturation (spillover) effect can be corrected using an inverse CEST ratio calculation. We postulated that a simplified qCEST analysis is feasible with omega plot analysis of the inverse CEST asymmetry calculation. Specifically, simulations showed that the numerically derived labile proton ratio and exchange rate were in good agreement with input values. In addition, the qCEST analysis was confirmed experimentally in a phantom with concurrent variation in CEST agent concentration and pH. Also, we demonstrated that the derived labile proton ratio increased linearly with creatine concentration (P < 0.01) while the pH‐dependent exchange rate followed a dominantly base‐catalyzed exchange relationship (P < 0.01). In summary, our study verified that a simplified qCEST analysis can simultaneously determine labile proton ratio and exchange rate in a relatively complex in vitro CEST system. Copyright © 2015 John Wiley & Sons, Ltd.     

Lorenz散点图在慢性心力衰竭患者心率变异性分析中的应用研究

目的 探讨洛伦兹(Lorenz)散点图在慢性心力衰竭患者图心率变异性(HRV)分析中的应用.方法 回顾性分析2017年9月至2020年9月安庆市立医院收治的34例心力衰竭患者的动态心电图检查资料,作为心衰组;选取同期行动态心电图检查的30例非心力衰竭患者作为对照组.比较2组HRV指标,包括时域频域指标:24 h内相邻窦...     

探讨血清HE4、CA125与TSGF检测对卵巢癌诊断的价值

目的探讨血清人附睾上皮分泌蛋白(HE4)、糖类抗原125(CA125)和肿瘤特异性生长因子(TSGF)检测在卵巢癌诊断中的价值。方法采用ELISA法检测HE4、化学发光法检测血清CA125,全自动生化法检测TSGF水平。采集85例卵巢癌患者、60例卵巢良性肿瘤患者及55例健康体检者血清,分析各标志物单项和联合检测对卵巢癌的诊断价值。结果卵巢癌患者血清HE4、CA125和TSGF水平均明显高于卵巢良性疾病患者组和健康对照组(P0.05),HE4、CA125和TSGF在卵巢癌组的阳性检出率分别为64.7%、72.9%和77.6%,与良性卵巢肿瘤组和健康对照组相比,差异有统计学意义(P0.05)。在卵巢癌单项标志物检测中,血清TSGF的灵敏度(77.8%)优于CA125、HE4;而血清HE4的特异度最高。HE4和TSGF联合检测的约登指数最高(64.8%)。血清HE4、TSGF联合检测对卵巢癌诊断的敏感度和阴性预测值均高于单项检测,分别为88.2%、82.1%,且高于HE4、CA125联合检测。结论在卵巢癌的早期诊断中血清HE4、TSGF联合检测比血清HE4、CA125联合检测更有意义。     

A modified test for small-study effects in meta-analyses of controlled trials with binary endpoints

Publication bias and related bias in meta-analysis is often examined by visually checking for asymmetry in funnel plots of treatment effect against its standard error. Formal statistical tests of funnel plot asymmetry have been proposed, but when applied to binary outcome data these can give false-positive rates that are higher than the nominal level in some situations (large treatment effects, or few events per trial, or all trials of similar sizes). We develop a modified linear regression test for funnel plot asymmetry based on the efficient score and its variance, Fisher's information. The performance of this test is compared to the other proposed tests in simulation analyses based on the characteristics of published controlled trials. When there is little or no between-trial heterogeneity, this modified test has a false-positive rate close to the nominal level while maintaining similar power to the original linear regression test ('Egger' test). When the degree of between-trial heterogeneity is large, none of the tests that have been proposed has uniformly good properties.