107 research outputs found

    Group Work Involved in the Practice of Life Education

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    With the continuous advancement of material civilization, the life values of college students appeared alienation. More and more students did not know how to face pressure and seek help; someone was to end their lives to solve the problem. Obliviously, life education was the urgent and necessary need in China. Therefore, the author explored the feasibility of life education from the angle of social work practice (such as the “group work”). Key words: Life education; Group work; College studentsResumé: Avec l'avancement continu de civilisation matérielle, les valeurs de vie d'étudiants universitaires ont apparu l'aliénation. De plus en plus les étudiants n'ont pas su comment faire face à la pression et chercher l'aide; quelqu'un devait finir leurs vies pour résoudre le problème. Apparemment, l'enseignement de vie était le besoin urgent et nécessaire en Chine. Donc, l'auteur a exploré la faisabilité d'enseignement de vie sous un angle de pratique (comme "le travail de groupe").Mots-clés: Enseignement de vie; Travail de groupe; Etudiants universitaire

    Understanding Track Substructure Behavior: Field Instrumentation Data Analysis and Development of Numerical Models

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    Numerous studies have targeted using numerical modeling, field instrumentation, or combinations of both to gain insight into track substructure behavior under loading. In-depth understanding of track substructure behavior serving both passenger and freight trains is critical to developing suitable design and maintenance/rehabilitation methods to ensure adequate performance under loading. This manuscript presents findings from a recently completed study involving advanced instrumentation and numerical modeling to investigate track substructure-related issues at several problematic railroad bridge approaches in the United States. Multi-Depth Deflectometers (MDDs) were installed to measure transient as well as plastic deformations experienced by track substructure layers under loading. Strain gauges were installed on the rail web to measure the vertical wheel loads applied during train passage. Data from the field instrumentation was used to make inferences regarding the relative contributions of different substructure layers towards the differential movement problem. A 3-D Finite Element (FE) model was developed to further understand the behavior of the instrumented locations, and was calibrated using the field instrumentation data. An elastic layered track analysis program, GEOTRACK, was first used to iteratively backcalculate individual track substructure layer moduli from the field measurements; these backcalculated modulus values were subsequently used in the FE model to predict track response under transient loading conditions. Modulus values estimated for the ballast layer were found to be significantly affected by the presence of gaps at the tie-ballast interface at track transitions. Once validated, the model was further modified to match transient displacement results acquired in the field using a quasi-static moving load approach. Good agreement was found between the model predictions and field instrumentation results. Development of advanced numerical models augmented by field instrumentation data can facilitate the design and maintenance of well-performing track structures

    Sustainable Aggregates Production: Green Applications for Aggregate By-Products

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    Increased emphasis in the construction industry on sustainability and recycling requires production of aggregate gradations with lower dust (cleaner aggregates) and smaller maximum sizes—hence, increased amount of quarry by-products (QBs). QBs are usually less than 1/4 in. (6 mm) in size. This report provides findings of an industry survey conducted among Illinois aggregate producers on the annual production rate, excess QBs generated, and current application areas of QBs. In addition, a detailed laboratory study was conducted to characterize the engineering properties of QB materials produced in the primary, secondary, and tertiary aggregate production stages from four different quarries operating in the State of Illinois. Since unconfined compressive strength for QB materials was low (less than 11 psi), chemical admixture stabilizers such as Portland cement and Class C fly ash were used to improve the strength properties of QB materials. Significant increases in the strength of stabilized QB materials observed may indicate suitability of QBs for sustainable pavement applications. Recommendations are made on potential strategies to utilize excess fines by incorporating QB materials in pavement construction.Illinois Department of Transportation, R27-125Ope

    Designing a multi-epitope vaccine to control porcine epidemic diarrhea virus infection using immunoinformatics approaches

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    Porcine epidemic diarrhea virus (PEDV), a continuously evolving pathogen, causes severe diarrhea in piglets with high mortality rates. However, current vaccines cannot provide complete protection against PEDV, so vaccine development is still necessary and urgent. Here, with the help of immunoinformatics approaches, we attempted to design a multi-epitope vaccine named rPMEV to prevent and control PEDV infection. The epitopes of rPMEV were constructed by 9 cytotoxic T lymphocyte epitopes (CTLs), 11 helper T lymphocyte epitopes (HTLs), 6 linear B cell epitopes (LBEs), and 4 conformational B cell epitopes (CBEs) based on the S proteins from the four representative PEDV G2 strains. To enhance immunogenicity, porcine β-defensin-2 (PBD-2) was adjoined to the N-terminal of the vaccine as an adjuvant. All of the epitopes and PBD-2 were joined by corresponding linkers and recombined into the multivalent vaccine, which is stable, antigenic, and non-allergenic. Furthermore, we adopted molecular docking and molecular dynamics simulation methods to analyze the interaction of rPMEV with the Toll-like receptor 4 (TLR4): a stable interaction between them created by 13 hydrogen bonds. In addition, the results of the immune simulation showed that rPMEV could stimulate both cellular and humoral immune responses. Finally, to raise the expression efficiency, the sequence of the vaccine protein was cloned into the pET28a (+) vector after the codon optimization. These studies indicate that the designed multi-epitope vaccine has a potential protective effect, providing a theoretical basis for further confirmation of its protective effect against PEDV infection in vitro and in vivo studies

    Developing a multi-epitope vaccine candidate to combat porcine epidemic diarrhea virus and porcine deltacoronavirus co-infection by employing an immunoinformatics approach

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    Coinfection of porcine epidemic diarrhea virus (PEDV) and porcine deltacoronavirus (PDCoV) is common in pig farms, but there is currently no effective vaccine to prevent this co-infection. In this study, we used immunoinformatics tools to design a multi-epitope vaccine against PEDV and PDCoV co-infection. The epitopes were screened through a filtering pipeline comprised of antigenic, immunogenic, toxic, and allergenic properties. A new multi-epitope vaccine named rPPMEV, comprising cytotoxic T lymphocyte-, helper T lymphocyte-, and B cell epitopes, was constructed. To enhance immunogenicity, the TLR2 agonist Pam2Cys and the TLR4 agonist RS09 were added to rPPMEV. Molecular docking and dynamics simulation were performed to reveal the stable interactions between rPPMEV and TLR2 as well as TLR4. Additionally, the immune stimulation prediction indicated that rPPMEV could stimulate T and B lymphocytes to induce a robust immune response. Finally, to ensure the expression of the vaccine protein, the sequence of rPPMEV was optimized and further performed in silico cloning. These studies suggest that rPPMEV has the potential to be a vaccine candidate against PEDV and PDCoV co-infection as well as a new strategy for interrupting the spread of both viruses

    Anxiety, depression, psychological stress and coping style in medical postgraduates in southeastern China when restricted to commuting between the campus and hospital during the COVID-19 pandemic

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    BackgroundAs the COVID-19 epidemic was gradually brought under control, a new autumn semester began in 2020. How was the mental health of postgraduates as they experienced quarantine at home, only commuting between the school and hospital?MethodsThe research was conducted in a cross-sectional online survey in October 2020. The data were collected from 1,645 medical postgraduates (master’s and doctoral students) by using the demographic information questionnaire, the Self-rating Depression Scale (SDS), the Self-rating Anxiety Scale (SAS), the Questionnaire on Psychological Stressors of Postgraduates (QPSP), the Simplified Coping Style Questionnaire (SCSQ) and the Social Support Rate Scale (SSRS). One-way ANOVA and Pearson correlation were used to explore the relationships among anxiety, depression, psychological stressors, social support and coping style. Structural equation modeling (SEM) was conducted to assess the mediation model.ResultsAmong the total of 1,645 medical postgraduates, 21.6% (n = 356) had self-rated depression symptoms, and 9.4% (n = 155) had self-rated anxiety symptoms. The main disturbances they experienced were employment, academic and interpersonal pressure. The master of third grade students had the highest employment pressure, and the master of second grade students had the highest academic and interpersonal pressure. Negative coping played a negative mediating role and social support played a positive mediating role in the relationships between perceived stress and anxiety (β = 0.027, P < 0.01; β = 0.124, P < 0.01) and depression (β = 0.016, P < 0.01; β = 0.193, P < 0.01).ConclusionMedical postgraduates in China restricted to studies on campus and in the hospital experienced psychological distress. Our results suggest that providing employment and learning guidance, while strengthening social support and guiding positive coping may be effective at improving the mental health of the medical graduate students, mediating their perceived stress and negative emotions

    Different Effects of Total Bilirubin on 90-Day Mortality in Hospitalized Patients With Cirrhosis and Advanced Fibrosis: A Quantitative Analysis

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    Introduction: Total bilirubin (TB) is a major prognosis predictor representing liver failure in patients with acute on chronic liver failure (ACLF). However, the cutoff value of TB for liver failure and whether the same cutoff could be applied in both cirrhotic and non-cirrhotic patients remain controversial. There is a need to obtain the quantitative correlation between TB and short-term mortality via evidence-based methods, which is critical in establishing solid ACLF diagnostic criteria.Methods: Patients hospitalized with cirrhosis or advanced fibrosis (FIB-4 > 1.45) were studied. TB and other variables were measured at baseline. The primary outcome was 90-day transplantation-free mortality. Multi-variable Cox proportional hazard model was used to present the independent risk of mortality due to TB. Generalized additive model and second derivate (acceleration) were used to plot the “TB-mortality correlation curves.” The mathematical (maximum acceleration) and clinical (adjusted 28-day transplantation-free mortality rate reaching 15%) TB cutoffs for liver failure were both calculated.Results: Among the 3,532 included patients, the number of patients with cirrhosis and advanced fibrosis were 2,592 and 940, respectively, of which cumulative 90-day mortality were 16.6% (430/2592) and 7.4% (70/940), respectively. Any increase of TB was found the independent risk factor of mortality in cirrhotic patients, while only TB >12 mg/dL independently increased the risk of mortality in patients with advanced fibrosis. In cirrhotic patients, the mathematical TB cutoff for liver failure is 14.2 mg/dL, with 23.3% (605/2592) patients exceeding it, corresponding to 13.3 and 25.0% adjusted 28- and 90-day mortality rate, respectively. The clinical TB cutoff for is 18.1 mg/dL, with 18.2% (471/2592) patients exceeding it. In patients with advanced fibrosis, the mathematical TB cutoff is 12.1 mg/dL, 33.1% (311/940) patients exceeding it, corresponding to 2.9 and 8.0% adjusted 28- and 90-day mortality rate, respectively; the clinical TB cutoff was 36.0 mg/dL, 1.3% (12/940) patients above it.Conclusion: This study clearly demonstrated the significantly different impact of TB on 90-day mortality in patients with cirrhosis and advanced fibrosis, proving that liver failure can be determined by TB alone in cirrhosis but not in advanced fibrosis. The proposed TB cutoffs for liver failure provides solid support for the establishment of ACLF diagnostic criteria

    Synthesis of Inorganic Semiconductor Materials for Solar-Based Technologies

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    There is an alarming increase of energy issues due to significant fossil fuel consumption. Some progress has been made to replace fossil fuels with renewable sources, among which, solar energy has always been considered as the ultimate solution to solve these problems. As a relatively new evolved type of solar cell, Dye-sensitized solar cells (DSSC), have been investigated intensively in recent years and they are very promising for their cost-effectiveness properties. Zinc oxide (ZnO) is one of best candidates for DSSC due to its low cost and high electron mobility, amongst others. In this thesis, highly branched ZnO nanostructures are synthesized with biologically inspired methods to control the crystal growth and the mechanism by which these grow are investigated. Further explorations of the structure-function relationships reveal potential pathways towards the improvement of DSSC performance.Besides DSSC, it is necessary to transform the solar energy to storable energy so it can be utilized during the night. Titanium dioxide (TiO2) for hydrogen generation through photoelectrolysis is one of the most promising candidates. We synthesize TiO2 nanowire arrays by homoepitaxial growth on templates, and precisely control the nanostructured properties such as nanowire diameter, length, density, etc.. In addition, photoelectrochemical performance has been conducted on TiO2 thin films with different nanostructures to investigate structure-function relationships.Another significant concern involves environmental pollution due to the discharge or emission of a variety of new chemicals, which are threatening environmental and public health. ZnO, as a photocatalytic material, can effectively degrade organic pollutants without byproducts. In this work, we utilized biologically inspired methods to template the synthesis of Zn-organic compound materials using organic scaffolds. The complex material was heat-treated to produce a ZnO-carbon composite material. The processing conditions have been extensively studied and it has been demonstrated that the composite material can effectively improve the photocatalytic performance versus carbon-free ZnO nanostructured materials
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