233 research outputs found

    An hp hp -version spectral collocation method for fractional Volterra integro-differential equations with weakly singular kernels

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    We present a multi-step spectral collocation method to solve Caputo-type fractional integro-differential equations (FIDEs) involving weakly singular kernels. We reformulate the problem as the second type Volterra integral equation (VIE) with two different weakly singular kernels. Based on these integral equations, we construct a multi-step Legendre-Gauss spectral collocation scheme for the problem. The hp hp -version convergence is established rigorously. To demonstrate the effectiveness of the suggested method and the validity of the theoretical results, the results of some numerical experiments are presented

    An assessment for health education and health promotion in chronic disease demonstration districts: a comparative study from Hunan Province, China

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    Background Cost-effective strategies of chronic disease control, integrated health education and health promotion play important roles in the programs of chronic disease demonstration districts in China. The performance of these districts can be directly assessed by their health education and promotion work. However, there have been only a few performance assessments done on these programs, most of which made without the inclusion of proper quality indicators. This study was designed to establish a framework of indicators for outcome evaluation of health education and promotion efforts in Chinese districts, and explore the factors involved in promoting these efforts. Methods A modified two-round Delphi survey was first used to construct quality indicators on a nine-point Likert scale. With those indicators, the rank sum ratio (RSR) method was then conducted through rank conversion and parametric statistics, to assess and classify the performance of ten districts or counties randomly chosen both from demonstration and non-demonstration districts in the Hunan province. Results The Delphi process produced seven themes and 25 sub-themes as quality indicators. The seven themes included organizational management, financial support, professional personnel, health education and promotion, residents’ health awareness and behaviors, residents’ satisfaction, and residents’ health literacy. The districts were classified into four levels by RSR as follows: One demonstration district at the first-ranked level, five other demonstration districts at the second-ranked level, all non-demonstration districts at the third-ranked level. None were at the fourth-qualified level. Discussion Chronic disease demonstration districts performed better on the work of health education and health promotion than the non-demonstration districts. The work should be focused on the following measures of chronic diseases: organizational management, financial support, media-related broadcasting, technical support, community-based promotion and supportive environment, and people’s enhanced awareness and health literacy

    Riverside Landslide Susceptibility Overview: Leveraging Artificial Neural Networks and Machine Learning in Accordance with the United Nations (UN) Sustainable Development Goals

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    Riverside landslides present a significant geohazard globally, posing threats to infrastructure and human lives. In line with the United Nations’ Sustainable Development Goals (SDGs), which aim to address global challenges, professionals in the field have developed diverse methodologies to analyze, assess, and predict the occurrence of landslides, including quantitative, qualitative, and semi-quantitative approaches. With the advent of computer programs, quantitative techniques have gained prominence, with computational intelligence and knowledge-based methods like artificial neural networks (ANNs) achieving remarkable success in landslide susceptibility assessments. This article offers a comprehensive review of the literature concerning the utilization of ANNs for landslide susceptibility assessment, focusing specifically on riverside areas, in alignment with the SDGs. Through a systematic search and analysis of various references, it has become evident that ANNs have emerged as the preferred method for these assessments, surpassing traditional approaches. The application of ANNs aligns with the SDGs, particularly Goal 11: Sustainable Cities and Communities, which emphasizes the importance of inclusive, safe, resilient, and sustainable urban environments. By effectively assessing riverside landslide susceptibility using ANNs, communities can better manage risks and enhance the resilience of cities and communities to geohazards. While the number of ANN-based studies in landslide susceptibility modeling has grown in recent years, the overarching objective remains consistent: researchers strive to develop more accurate and detailed procedures. By leveraging the power of ANNs and incorporating relevant SDGs, this survey focuses on the most commonly employed neural network methods for riverside landslide susceptibility mapping, contributing to the overall SDG agenda of promoting sustainable development, resilience, and disaster risk reduction. Through the integration of ANNs in riverside landslide susceptibility assessments, in line with the SDGs, this review aims to advance our knowledge and understanding of this field. By providing insights into the effectiveness of ANNs and their alignment with the SDGs, this research contributes to the development of improved risk management strategies, sustainable urban planning, and resilient communities in the face of riverside landslides

    COVID-19 vaccination coverage among adolescents aged 12–17 years in three provinces of eastern China: A cross-sectional survey, 2021

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    High vaccination coverage is essential to prevent and control the spread of the COVID-19 epidemic. Currently, the real-world acceptance of COVID-19 vaccines among adolescents aged 12–17 years in China has not been reported. We aimed to assess the acceptance rate of COVID-19 vaccination among adolescents in eastern China and to identify factors associated with the intention to get vaccinated against COVID-19. We conduct a cross-sectional questionnaire survey among adolescents from three provinces in the eastern part of China from 16 August to 28 October 2021. The questionnaires were distributed to 2,100 students, and 2,048 students completed the questionnaires. The results showed that 98.4% (2,016/2,048) of adolescents had received at least one dose of the COVID-19 vaccine and 1.6% (32/2,048) declined the vaccination. The participants from rural districts, or whose parents were vaccinated, were more likely to accept the vaccine. The main reason for declining vaccination was worry about vaccine safety (25%). The main adverse event after the vaccination was pain at the injection site. In conclusion, the vaccine coverage rate reached 98.4% among the adolescents in this study, which met the criteria for herd immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The high vaccination rate is beneficial to the prevention and control of the COVID-19 pandemic

    Reliability of wind turbine power modules using high-resolution wind data reconstruction : a digital twin concept

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    This study introduces a Digital Twin (DT) framework for the reliability assessment of wind turbine power modules. Its importance is demonstrated by examining the effect of wind turbulence on the electrothermal behaviour and lifetime of machine side power electronic converters and semiconductor devices of direct-drive wind turbines. To this end, an electrothermal model embedded in a turbine model is established, which tracks the changes in wind speed. Using real-world, 1-sec wind speed data, the real device junction temperature profiles and the fatigue experienced by the semiconductor devices are examined for two 10-min periods. Then, these metrics are compared with the corresponding metrics of the same 10-min periods when the wind speed is assumed constant and equal to the 10-min average value, which is often used in traditional device reliability assessment methods using SCADA data. Based on simulation results, the fatigue experienced by the semiconductor devices due to sudden fluctuations of the wind is found to be significantly higher than the fatigue estimated by traditional reliability assessment methods using the SCADA data. Two methods that attempt to reconstruct the wind spectrum (Random Walk Metropolis-Hastings algorithm) and compress the wind speed data (Discrete Wavelet Transform) are proposed. These and/or other similar methods may be integrated into the DT interface to address the issue of the large volume of data required to be stored in DTs

    Comparative Molecular Field Analysis (CoMFA) and Comparative Molecular Similarity Indices Analysis (CoMSIA) Studies on α1A-Adrenergic Receptor Antagonists Based on Pharmacophore Molecular Alignment

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    The α1A-adrenergic receptor (α1A-AR) antagonist is useful in treating benign prostatic hyperplasia, lower urinary tract symptoms, and cardiac arrhythmia. Three-dimensional quantitative structure-activity relationship (3D-QSAR) studies were performed on a set of α1A-AR antagonists of N-aryl and N-nitrogen class. Statistically significant models constructed from comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were established based on a training set of 32 ligands using pharmacophore-based molecular alignment. The leave-oneout cross-validation correlation coefficients were q2 CoMFA = 0.840 and q2 CoMSIA = 0.840. The high correlation between the cross-validated/predicted and experimental activities of a test set of 12 ligands revealed that the CoMFA and CoMSIA models were robust (r2 pred/CoMFA = 0.694; r2 pred/CoMSIA = 0.671). The generated models suggested that electrostatic, hydrophobic, and hydrogen bonding interactions play important roles between ligands and receptors in the active site. Our study serves as a guide for further experimental investigations on the synthesis of new compounds. Structural modifications based on the present 3D-QSAR results may lead to the discovery of other α1A-AR antagonists

    A fatal case of oral intoxication by mustard gas

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    Opisan je slučaj peroralne intosikacije iperitom u namjeri samoubojstva i iznesen obdukcioni nalaz. Ukratko su izneseni neki toksikološki pogledi na otrovanje iperifom, te klinički simptomi i patomorfološke promjene kod intoksikacije ovim otrovom.A case is presented of a man aged 27 who swallowed 50 g of mustard gas (dichlor-diethylsulphide) in order to commit suicide. Although immediately treated at the Internal Clinic of the Medical Faculty, he died 8 hours and 20 minutes after taking the poison. A postmortem examination carried out 19 hours after death, as well as histological findings showed congestion and oedema of the brain, fragmentation of cardiac muscle, oedema of mucous membranes of the upper part of gastrointestinal tract, oedema of larynx and epiglotis, oedema of the liver, and congestion of the spleen, adrenal glands, and kidneys. A microscopic examination of the lung tissue revealed hemorrhages probably due to the irritative effect of the poison

    The Epidemiological Characteristics of Stroke in Hunan Province, China

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    Previous studies have shown that Hunan Province has a high incidence of stroke and a high proportion of intracerebral hemorrhage (ICH). Considering the changes over the past three decades, little is known about the current epidemiological characteristics of stroke in Hunan Province. In 2013, a cross-sectional study was conducted at seven national disease surveillance points (DSPs) in Hunan Province. A multistage cluster sampling method was used to select a representative sample. A total of 21,156 participants aged 20 years and older were examined. Among the 21,156 participants, the number of prevalent strokes, incident strokes and deaths was 307, 87, and 36, respectively. The 2010 China census-standardized prevalence, incidence and mortality were 1191.0 per 100,000 people [95% confidence interval (CI) 1044.8–1337.2], 333.6 per 100,000 person-years (95% CI 255.7–411.5) and 129.7 per 100,000 person-years (95% CI 81.1–178.3), respectively. Ischemic stroke (IS), ICH, subarachnoid hemorrhage (SAH), and stroke of undetermined type (UND) constituted 50.6, 41.4, 5.7, and 2.3% of all incident stroke cases, respectively. Tianxin, Liuyang, Wuling, and Hongjiang have high proportions of ICH (61.5, 58.3, 60, and 50%, respectively). Hypertension is the most common risk factor for prevalent stroke (71.34%), followed by smoking (30.62%) and alcohol use (25.73%). In conclusion, Hunan Province has an extremely heavy stroke burden. The high proportion of ICH is not limited to the Changsha community; it represents an important issue for all of Hunan Province

    Вихретоковый анизотропный термоэлектрический первичный преобразователь лучистого потока

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    Представлена оригинальная конструкция первичного преобразователя лучистого потока, который может служить основой для создания приемника неселективного излучения с повышенной чувствительностью
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