42 research outputs found

    The hidden inequality: the disparities in the quality of daily use masks associated with family economic status

    Get PDF
    Wearing high-quality masks plays a critical role in reducing COVID-19 transmission. However, no study has investigated socioeconomic inequality in the quality of masks. Addressing this gap, this paper explored the relationships between mask’s quality and family economic status. The cross-sectional survey was conducted in two Chinese universities by distributing structured questionnaires to assess participants’ characteristics including family economic status, and meanwhile collecting their masks to evaluate the quality by measuring particle filtration efficiency. The valid responses were obtained from 912 students with mean age of 19.556 ± 1.453  years and were analyzed by using fractional or binary logistic regression. Three main findings were presented. First, inequality existed in the quality of masks. 36.07% of students were using unqualified masks with average filtration efficiency of 0.795 ± 0.119, which was much lower than China’s national standard (0.9). Of those masks with identified production date, 11.43% were manufactured during COVID-19 outbreak when market was flooded with counterfeit production, and thus were of poor quality with average filtration efficiency of 0.819 ± 0.152. Second, better family economic status was associated with better masks’ filtration efficiency and greater probability of using qualified masks. Third, students with better family economic status tend to use masks with individual packaging, and unique patterns and special designs, which may lead to inequality on a psychological level. Our analysis reveals the hidden socioeconomic inequality that exist behind cheap masks. In facing the challenges of future emerging infectious diseases, it is important to address the inequity to ensure equal access to affordable qualified personal protection equipment

    Multi-site, Multi-domain Airway Tree Modeling (ATM'22): A Public Benchmark for Pulmonary Airway Segmentation

    Full text link
    Open international challenges are becoming the de facto standard for assessing computer vision and image analysis algorithms. In recent years, new methods have extended the reach of pulmonary airway segmentation that is closer to the limit of image resolution. Since EXACT'09 pulmonary airway segmentation, limited effort has been directed to quantitative comparison of newly emerged algorithms driven by the maturity of deep learning based approaches and clinical drive for resolving finer details of distal airways for early intervention of pulmonary diseases. Thus far, public annotated datasets are extremely limited, hindering the development of data-driven methods and detailed performance evaluation of new algorithms. To provide a benchmark for the medical imaging community, we organized the Multi-site, Multi-domain Airway Tree Modeling (ATM'22), which was held as an official challenge event during the MICCAI 2022 conference. ATM'22 provides large-scale CT scans with detailed pulmonary airway annotation, including 500 CT scans (300 for training, 50 for validation, and 150 for testing). The dataset was collected from different sites and it further included a portion of noisy COVID-19 CTs with ground-glass opacity and consolidation. Twenty-three teams participated in the entire phase of the challenge and the algorithms for the top ten teams are reviewed in this paper. Quantitative and qualitative results revealed that deep learning models embedded with the topological continuity enhancement achieved superior performance in general. ATM'22 challenge holds as an open-call design, the training data and the gold standard evaluation are available upon successful registration via its homepage.Comment: 32 pages, 16 figures. Homepage: https://atm22.grand-challenge.org/. Submitte

    Early warning of stator winding overheating fault of water-cooled turbogenerator based on SAE-LSTM and sliding window method

    No full text
    Aiming at the early warning of overheating defects in the stator winding of water-cooled turbogenerators, this paper proposes a novel method based on SAE-LSTM and sliding window method by combining the Sparse Auto-Encoder (SAE) and the Long–Short Term Memory network (LSTM) with highly time dependent time series data characteristics. Firstly, the sparse auto-encoder is used to reconstruct the operation data collected by the Distributed Control System (DCS) installed on the turbogenerator to extract the data characteristics; Secondly, the LSTM prediction model optimized by attention mechanism is used to predict the outlet temperature of each slot of the stator winding of the turbogenerator under normal working condition; Then, the sliding window method is adopted to detect the stator winding overheating defect, and the alarm threshold is defined based on both the maximum mean value and maximum standard deviation of the predicted residual within the window. Finally, the proposed method is validated by using the historical DCS data of a turbo generator with stator winding overheating defect before failure,and the results show that compared with the traditional threshold warning method, the proposed method can warn the defects 85 h in advance, which provides strong support for the stable operation of the turbogenerator

    Maxwell-Equations Based on Mining Transient Electromagnetic Method for Coal Mine-Disaster Water Detection

    No full text
    Water-bearing geological structure is a serious threat to coalmine safety. This research focuses on detecting water-bearing geological structure by transient electromagnetic method. First, we introduce the principle of mining transient electromagnetic method, and then explain the technique of Finite Different Time Domain using in the transient electromagnetic method. Based on Maxwell equations, we derive the difference equations of electromagnetic field and study the responses of water-bearing geological structure using FDTD. Moreover, we establish the relationship between receiving electromagnetic field and geological information. The typical coal geological model of goaf-water is chosen to do the numerical simulation. Besides, we verify the availability of the method by numerical simulation using coal geological model. Finally, we use the method in the coalmine which is located in Linfen city in Shanxi province in China, and the detecting result is verified by drilling

    A novel decoupled parallel mechanism with two translational and one rotational degree of freedom and its performance indices analysis

    No full text
    Less degrees of freedom parallel mechanism is widely used in many fields with its unique advantages. A decoupled parallel mechanism with 2 degree-of-freedom translation and 1 degree-of-freedom rotation is presented, and its performance evaluation indices analysis is performed. By the constraint screw method, the motion feature of the mechanism and its number of degree of freedom are analyzed. The constrained equations of the mechanism are established according to the constrained conditions of the pole length. The analytical expression of the forward and inverse position for the mechanism is deduced, and the expression of the Jacobian matrix is derived, which validated the decoupling feature of the mechanism. The singularity of the mechanism is also carried out. The performance evaluation indices for the decoupled parallel mechanism are discussed and the corresponding performance indices analysis of the proposed decoupled parallel mechanism is executed. The novel decoupled parallel mechanism presented herein enriches the parallel mechanism structure, and the definition and analysis of the performance evaluation indices should be meaningful for the further design and optimization of the decoupled parallel mechanism

    The characteristic analysis of phase-controlled array thermo-acoustic emission with multiple emitting surfaces

    No full text
    Abstract Thermo-acoustic (TA) ultrasound, particularly when combined with phased-controlled array technology, has garnered significant interest in the past decade due to its numerous advantages. This paper establishes a theoretical expression for thermo-acoustic phased array (TAPA) emission to investigate different acoustic fields based on input heat flow frequencies, quantities and distances of TA emission surfaces, area of emission surfaces, and phase changes between emission surfaces. The study finds that a TAPA with two emitting surfaces in a line pattern produces a consistent acoustic field compared to a single emitting surface arranged in a semicircle. Additionally, applying different phases on the surfaces narrows the scanning range with an increase in frequency, area of the TA emission surface, and the amount of emission surfaces, while enhancing the directivity of the TA wave. Moreover, increasing the distance between emitting surfaces in a square-shaped TAPA does not affect the ultrasound pressure of the main TA ultrasound but increases the quantity and size of side lobes. Furthermore, enlarging the area of emitting surfaces enhances the directivity of the TA ultrasound, necessitating a reduction in the distance between emitting surfaces or an increase in the area of the emitting surfaces in a square-shaped TAPA to enhance directivity. This paper provides a comprehensive study of TAPA to aid further research in this field

    Physiology and Molecular Breeding in Sustaining Wheat Grain Setting and Quality under Spring Cold Stress

    No full text
    Spring cold stress (SCS) compromises the reproductive growth of wheat, being a major constraint in achieving high grain yield and quality in winter wheat. To sustain wheat productivity in SCS conditions, breeding cultivars conferring cold tolerance is key. In this review, we examine how grain setting and quality traits are affected by SCS, which may occur at the pre-anthesis stage. We have investigated the physiological and molecular mechanisms involved in floret and spikelet SCS tolerance. It includes the protective enzymes scavenging reactive oxygen species (ROS), hormonal adjustment, and carbohydrate metabolism. Lastly, we explored quantitative trait loci (QTLs) that regulate SCS for identifying candidate genes for breeding. The existing cultivars for SCS tolerance were primarily bred on agronomic and morphophysiological traits and lacked in molecular investigations. Therefore, breeding novel wheat cultivars based on QTLs and associated genes underlying the fundamental resistance mechanism is urgently needed to sustain grain setting and quality under SCS

    Truncated FRMD7 proteins in congenital Nystagmus: novel frameshift mutations and proteasomal pathway implications

    No full text
    Abstract Idiopathic congenital nystagmus (ICN) manifests as involuntary and periodic eye movements. To identify the genetic defect associated with X-linked ICN, Whole Exome Sequencing (WES) was conducted in two affected families. We identified two frameshift mutations in FRMD7, c.1492dupT/p.(Y498Lfs*15) and c.1616delG/p.(R539Kfs*2). Plasmids harboring the mutated genes and qPCR analysis revealed mRNA stability, evading degradation via the NMD pathway, and corroborated truncated protein production via Western-blot analysis. Notably, both truncated proteins were degraded through the proteasomal (ubiquitination) pathway, suggesting potential therapeutic avenues targeting this pathway for similar mutations. Moreover, we conducted a comprehensive analysis, summarizing 140 mutations within the FRMD7 gene. Our findings highlight the FERM and FA structural domains as mutation-prone regions. Interestingly, exons 9 and 12 are the most mutated regions, but 90% (28/31) mutations in exon 9 are missense while 84% (21/25) mutations in exon 12 are frameshift. A predominant occurrence of shift code mutations was observed in exons 11 and 12, possibly associated with the localization of premature termination codons (PTCs), leading to the generation of deleterious truncated proteins. Additionally, our conjecture suggests that the loss of FRMD7 protein function might not solely drive pathology; rather, the emergence of aberrant protein function could be pivotal in nystagmus etiology. We propose a dependence of FRMD7 protein normal function primarily on its anterior domain. Future investigations are warranted to validate this hypothesis
    corecore