A review of air filtration technologies for sustainable and healthy building ventilation

Urbanization increased population density in cities and consequently leads to severe indoor air pollution. As a result of these trends, the issue of sustainable and healthy indoor environment has received increasing attention. Various air filtration techniques have been adopted to optimize indoor air quality. Air filtration technique can remove air pollutants and effectively alleviate the deterioration of indoor air quality. This paper presents a comprehensive review on the synergistic effect of different air purification technologies, air filtration theory, materials and standards. It evaluated different air filtration technologies by considering factors such as air quality improvement, filtering performance, energy and economic behaviour, thermal comfort and acoustic impact. Current research development of air filtration technologies along with their advantages, limitations and challenges are discussed. This paper aims to drive the future of air filtration technology research and development in achieving sustainable and healthy building ventilation

Ultrasound radiomics models based on multimodal imaging feature fusion of papillary thyroid carcinoma for predicting central lymph node metastasis

ObjectiveThis retrospective study aimed to establish ultrasound radiomics models to predict central lymph node metastasis (CLNM) based on preoperative multimodal ultrasound imaging features fusion of primary papillary thyroid carcinoma (PTC).MethodsIn total, 498 cases of unifocal PTC were randomly divided into two sets which comprised 348 cases (training set) and 150 cases (validition set). In addition, the testing set contained 120 cases of PTC at different times. Post-operative histopathology was the gold standard for CLNM. The following steps were used to build models: the regions of interest were segmented in PTC ultrasound images, multimodal ultrasound image features were then extracted by the deep learning residual neural network with 50-layer network, followed by feature selection and fusion; subsequently, classification was performed using three classical classifiers—adaptive boosting (AB), linear discriminant analysis (LDA), and support vector machine (SVM). The performances of the unimodal models (Unimodal-AB, Unimodal-LDA, and Unimodal-SVM) and the multimodal models (Multimodal-AB, Multimodal-LDA, and Multimodal-SVM) were evaluated and compared.ResultsThe Multimodal-SVM model achieved the best predictive performance than the other models (P < 0.05). For the Multimodal-SVM model validation and testing sets, the areas under the receiver operating characteristic curves (AUCs) were 0.910 (95% CI, 0.894-0.926) and 0.851 (95% CI, 0.833-0.869), respectively. The AUCs of the Multimodal-SVM model were 0.920 (95% CI, 0.881-0.959) in the cN0 subgroup-1 cases and 0.828 (95% CI, 0.769-0.887) in the cN0 subgroup-2 cases.ConclusionThe ultrasound radiomics model only based on the PTC multimodal ultrasound image have high clinical value in predicting CLNM and can provide a reference for treatment decisions

“Caracterización de los sistemas de producción de ovinos de pelo en el suroeste del departamento de Matagalpa 2010”

Con el objetivo de caracterizar los sistemas de producción de ovinos de pelo en el territorio suroeste del departamento de Matagalpa 2010. (Sébaco, Ciudad Darío, San Isidro y Matagalpa). Se aplicó una encuesta a 103 productores que poseen ovinos de pelo, la muestra se definió aleatoriamente utilizando la ecuación planteada por Scheaffer (1987), se utilizó la técnica de muestreo de bola de nieve, planteada por Frey et al (2000). Esta investigación permitió conocer las debilidades y oportunidades en los sistemas de explotación de esta especie promisoria para la zona seca del país. Con los resultados obtenidos de las encuestas se procedió ha elaborar una base de datos en el programa SPSS versión 11.5 en español. Encontrando un predominio del sexo femenino como titulares de las explotaciones ovinas, 58.3% cursó educación primaria, el 98% de las explotaciones cuentan con raza pelibuey, el 100% de las explotaciones realizan destete y monta de forma natural, una media de mortalidad de corderos de 1, alimentan a las ovejas con potrero sin división (81.6%), se suministra pasto de corte, pastoreo, leguminosas y se suplementa sal común 49.5%, aplican vacunas contra ántrax y pierna negra (63.1%), desparasitaciones internas y externas (66%), ambos con una frecuencia de 2 veces al año, en el manejo productivo no se lleva control en la actividad ovina (100%), los equipo e instalaciones son rústicas, los corrales ovinos el son elaborados con alambre y/o madera, techado con plástico y/o zinc (49.51%), en cuanto a asistencia técnica el 58.3% ha recibid

Helicobacter pylori infection increases the risk of carotid plaque formation: Clinical samples combined with bioinformatics analysis

Objective: Infection with Helicobacter pylori (H. pylori) may increase atherosclerosis, which can lead to carotid plaque formation. Our study examined the relationship between H. pylori infection and carotid plaque formation, and its underlying mechanisms. Methods: A total of 36,470 people who underwent physical examination in Taizhou Hospital Health Examination Center from June 2017 to June 2022 were included in this study. All people participated in the urease test, neck ultrasound, blood pressure detection, anthropometric measurement and biochemical laboratory examination. In addition, the GSE27411 and GSE28829 datasets in the Gene Expression Omnibus (GEO) database were used to analyze the mechanism of H. pylori infection and atherosclerosis progression. Results: H. pylori infection, sex, age, blood lipids, blood pressure, fasting blood glucose, glycated hemoglobin and body mass index were risk factors for carotid plaque formation. An independent risk factor was still evident in the multivariate logistic regression analysis, indicating H. pylori infection. Furthermore, after weighted gene coexpression network analysis (WGCNA), we discovered 555 genes linked to both H. pylori infection and the advancement of atherosclerosis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed a strong correlation between these genes and immunity, infection, and immune disorders. SsGSEA analysis showed that H. pylori infection and atherosclerosis included changes in the immune microenvironment. Finally, three genes MS4A6A, ADAMDEC1 and AQP9 were identified to be involved in the formation of atherosclerosis after H. pylori infection. Conclusion: Our research affirms that H. pylori is a unique contributor to the formation of carotid plaque, examines the immune microenvironment associated with H. pylori infection and advanced carotid atherosclerosis, and offers fresh perspectives on how H. pylori infection leads to atherosclerosis

Development and Application of Liquid Metal Cooled Fast Reactor Sub-channel Analysis Code SACOS-LMR

Against the backdrop of China's ambitious three-step nuclear energy development strategy, encompassing pressurized water reactors (PWR), fast reactors (FR), and fusion reactors (FNR), the purpose of this study is to meet the pivotal need for a specialized sub-channel analysis code tailored to the unique thermal-hydraulic characteristics of liquid metal fast reactors (LMFRs). Building upon the foundational SACOS sub-channel code, the approach involves the seamless integration of LMFR-specific models. These include the wire-wrapped model, turbulent crossflow model, and liquid metal convective heat exchange model. The utilization of advanced computational techniques, such as the SIMPLE algorithm and staggered grid methodology, ensures the completion of accurate sub-channel calculations, establishing SACOS-LMR as a robust code for thermal-hydraulic safety analysis in LMFRs. Validation of the SACOS-LMR code was conducted through a sodium transient experiment involving 37-pin bundles at the Karlsruhe Institute of Technology. The results not only demonstrate a commendable alignment between computed parameters (e.g. temperature distribution, pressure drop) and experimental values but also confirm the code's precision in transient analysis for LMFRs. Applying the validated SACOS-LMR code, an in-depth thermal-hydraulic safety analysis of the European Lead-cooled Fast Reactor (ALFRED) core was conducted. The calculated results are not only reasonable but also exhibit consistency with comparable codes, affirming SACOS-LMR's applicability for LMFR core design and thermal-hydraulic analysis. In conclusion, this research represents a significant step forward in the development of LMFR technology. SACOS-LMR, with its validated capability in both steady-state and transient analysis, stands as a sophisticated and reliable sub-channel analysis tool. It not only supports LMFR core design but also contributes to the broader global pursuit of sustainable and clean energy solutions in the nuclear energy landscape

Correction: Association of GST Genetic Polymorphisms with the Susceptibility to Hepatocellular Carcinoma (HCC) in Chinese Population Evaluated by an Updated Systematic Meta-Analysis

BACKGROUND: Due to the possible involvement of Glutathione S-transferase Mu-1 (GSTM1) and Glutathione S-transferase theta-1 (GSTT1) in the detoxification of environmental carcinogens, environmental toxins, and oxidative stress products, genetic polymorphisms of these two genes may play important roles in the susceptibility of human being to hepatocellular carcinoma. However, the existing research results are not conclusive. METHODS: A systematic literature search using databases (PubMed, Scopus, Embase, Chinese Biomedical Database, Chinese National Knowledge Infrastructure, Wanfang Data, etc.) for the eligible studies meeting the inclusion criteria including case-control studies or cohort studies is evaluated using an updated systematic meta-analysis. RESULTS: Significant increase in the risk of HCC in the Chinese population is found in GSTM1 null genotype (OR = 1.47, 95% CI: 1.21 to 1.79, P<0.001) and GSTT1 null genotype (OR = 1.38, 95% CI: 1.14 to 1.65, P<0.001). Analysis using the random-effects model found an increased risk of HCC in GSTM1-GSTT1 dual null population (OR = 1.79, 95% CI: 1.26 to 2.53, P<0.001). In addition, subgroup analyses showed a significant increase in the association of GST genetic polymorphisms (GSTM1, GSTT1, and GSTM1-GSTT1) with HCC in southeast and central China mainland. However, available data collected by this study fail to show an association between GST genetic polymorphisms and HCC in people from the Taiwan region (for GSTM1: OR = 0.78, 95% CI: 0.60 to 1.01, P = 0.06; for GSTT1: OR = 0.94, 95% CI: 0.78 to 1.14, P = 0.546; for GSTM1-GSTT1: OR = 1.04, 95% CI: 0.81 to 1.32, P = 0.77). Sensitivity analysis and publication bias diagnostics confirmed the reliability and stability of this meta-analysis. CONCLUSIONS: Our results indicate that both GSTM1 and GSTT1 null genotypes are associated with an increased HCC risk in Chinese population. Peoples with dual null genotypes of GSTM1-GSTT1 are more susceptible to developing HCC. In conclusion, GST genetic polymorphisms play vital roles in the development of HCC in the Chinese population

A digital direct controller for buck converter

International audienceA novel integrated digital controller for buck converter based on the direct system-variable calculation is presented. Compared with linear compensators, the discrete-time direct controller is conceived to generate an additional control variable during each switching period that increases the convergence rate when system states change. An all-digital current estimator is adopted to eliminate the use of current sensor. Experimental results verify closed-loop operation at switching frequency up to 4MHz. The dynamic response time for a load current step-up from 0.3A to 0.45A is 23.8μs, and 21.4μs for a step-down from 0.45A to 0.3A. An efficiency of over 75% is maintained over a power range from 29.3mW to 1.12W in which the maximum efficiency of 93.2% is achieved at 1.88V output