626 research outputs found

    Linear programming method to construct equated item sets for the implementation of periodical computer-based testing for the Korean Medical Licensing Examination

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    Purpose This study aimed to identify the best way of developing equivalent item sets and to propose a stable and effective management plan for periodical licensing examinations. Methods Five pre-equated item sets were developed based on the predicted correct answer rate of each item using linear programming. These pre-equated item sets were compared to the ones that were developed with a random item selection method based on the actual correct answer rate (ACAR) and difficulty from item response theory (IRT). The results with and without common items were also compared in the same way. ACAR and the IRT difficulty were used to determine whether there was a significant difference between the pre-equating conditions. Results There was a statistically significant difference in IRT difficulty among the results from different pre-equated conditions. The predicted correct answer rate was divided using 2 or 3 difficulty categories, and the ACAR and IRT difficulty parameters of the 5 item sets were equally constructed. Comparing the item set conditions with and without common items, including common items did not make a significant contribution to the equating of the 5 item sets. Conclusion This study suggested that the linear programming method is applicable to construct equated-item sets that reflect each content area. The suggested best method to construct equated item sets is to divide the predicted correct answer rate using 2 or 3 difficulty categories, regardless of common items. If pre-equated item sets are required to construct a test based on the actual data, several methods should be considered by simulation studies to determine which is optimal before administering a real test

    In-rich InGaN/GaN quantum wells grown by metal-organic chemical vapor deposition

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    Growth mechanism of In-rich InGaN/GaN quantum wells (QWs) was investigated. First, we examined the initial stage of InN growth on GaN template considering strain-relieving mechanisms such as defect generation, islanding, and alloy formation at 730 degrees C. It was found that, instead of formation of InN layer, defective In-rich InGaN layer with thickness fluctuations was formed to relieve large lattice mismatch over 10% between InN and GaN. By introducing growth interruption (GI) before GaN capping at the same temperature, however, atomically flat InGaN/GaN interfaces were observed, and the quality of In-rich InGaN layer was greatly improved. We found that decomposition and mass transport processes during GI in InGaN layer are responsible for this phenomenon. There exists severe decomposition in InGaN layer during GI, and a 1-nm-thick InGaN layer remained after GI due to stronger bond strength near the InGaN/GaN interface. It was observed that the mass transport processes actively occurred during GI in InGaN layer above 730 degrees C so that defect annihilation in InGaN layer was greatly enhanced. Finally, based on these experimental results, we propose the growth mechanism of In-rich InGaN/GaN QWs using GI.open9

    Dietary pattern and health-related quality of life among breast cancer survivors

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    Background There is limited evidence for the association between dietary pattern and quality of life among breast cancer survivors. We examined the association between dietary patterns and health-related quality of life (HRQoL) among Korean breast cancer survivors. Methods Our study included a total of 232 women, aged 21 to 79 years, who had been diagnosed with stage I to III breast cancer and who underwent breast cancer surgery at least 6 months prior to our baseline evaluation. We assessed HRQoL using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) and the Quality of Life Questionnaire Breast Cancer Module 23 (QLQ-BR23). We conducted a factor analysis to identify the major dietary patterns and used a generalized linear model to obtain the least squares mean (LS mean) and 95% confidence interval (CI) for HRQoL according to the dietary pattern scores. Results We identified 2 major dietary patterns: the Healthy dietary pattern and the Western dietary pattern. We found that breast cancer survivors who had higher Healthy dietary pattern scores tended to have lower dyspnea scores but higher insomnia scores, compared to breast cancer survivors with lower Healthy dietary pattern scores. For dyspnea, the LS mean (95% CI) was 8.86 (5.05-15.52) in the bottom quartile and 2.87 (1.62-5.08) in the top quartile (p for trend = 0.005). This association was limited to survivors with stage I for dyspnea or survivors with stage II or III for insomnia. Conclusions Healthy dietary patterns were associated with better scores for dyspnea but worse scores for insomnia among breast cancer survivors. Other components of EORTC QLQ did not vary by dietary patterns overall, but they warrant further investigation for subgroups of breast cancer survivors.This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (NRF-2014R1A2A2A01007794). The funding body had no role in the design of the study, collection, analysis and interpretation of data, and manuscript writing

    Gender Differences and Effect of Air Pollution on Asthma in Children with and without Allergic Predisposition: Northeast Chinese Children Health Study

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    BACKGROUND: Males and females exhibit different health responses to air pollution, but little is known about how exposure to air pollution affects juvenile respiratory health after analysis stratified by allergic predisposition. The aim of the present study was to assess the relationship between air pollutants and asthmatic symptoms in Chinese children selected from multiple sites in a heavily industrialized province of China, and investigate whether allergic predisposition modifies this relationship. METHODOLOGY/PRINCIPAL FINDINGS: 30139 Chinese children aged 3-to-12 years were selected from 25 districts of seven cities in northeast China in 2009. Information on respiratory health was obtained using a standard questionnaire from the American Thoracic Society. Routine air-pollution monitoring data was used for particles with an aerodynamic diameter ≤10 µm (PM(10)), sulfur dioxide (SO(2)), nitrogen dioxides (NO(2)), ozone (O(3)) and carbon monoxide (CO). A two-stage regression approach was applied in data analyses. The effect estimates were presented as odds ratios (ORs) per interquartile changes for PM(10), SO(2), NO(2), O(3), and CO. The results showed that children with allergic predisposition were more susceptible to air pollutants than children without allergic predisposition. Amongst children without an allergic predisposition, air pollution effects on asthma were stronger in males compared to females; Current asthma prevalence was related to PM(10) (ORs = 1.36 per 31 µg/m(3); 95% CI, 1.08-1.72), SO(2) (ORs = 1.38 per 21 µg/m(3); 95%CI, 1.12-1.69) only among males. However, among children with allergic predisposition, more positively associations between air pollutants and respiratory symptoms and diseases were detected in females; An increased prevalence of doctor-diagnosed asthma was significantly associated with SO(2) (ORs = 1.48 per 21 µg/m(3); 95%CI, 1.21-1.80), NO(2) (ORs = 1.26 per 10 µg/m(3); 95%CI, 1.01-1.56), and current asthma with O(3) (ORs = 1.55 per 23 µg/m(3); 95%CI, 1.18-2.04) only among females. CONCLUSION/SIGNIFICANCE: Ambient air pollutions were more evident in males without an allergic predisposition and more associations were detected in females with allergic predisposition

    Diverse impacts of the rs58542926 E167K variant in TM6SF2 on viral and metabolic liver disease phenotypes

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    A genome-wide exome association study has identified the transmembrane 6 superfamily member 2 (TM6SF2) rs58542926 variant encoding an E167K substitution as a genetic determinant of hepatic steatosis in nonalcoholic fatty liver disease (NAFLD). The roles of this variant across a spectrum of liver diseases and pathologies and on serum lipids comparing viral hepatitis to NAFLD and viral load in chronic viral hepatitis, as well as its intrahepatic molecular signature, have not been well characterized. We undertook detailed analyses in 3260 subjects with viral and nonviral liver diseases and in healthy controls. Serum inflammatory markers and hepatic expression of TM6SF2 and genes regulating lipid metabolism were assessed in a subset with chronic hepatitis C (CHC). The rs58542926 T allele was more prevalent in 502 NAFLD patients than controls (P = 0.02) but not different in cohorts with CHC (n = 2023) and chronic hepatitis B (n = 507). The T allele was associated with alterations in serum lipids and hepatic steatosis in all diseases and with reduced hepatic TM6SF2 and microsomal triglyceride transfer protein expression. Interestingly, the substitution was associated with reduced CHC viral load but increased hepatitis B virus DNA. The rs58542926 T allele had no effect on inflammation, impacted >= F2 fibrosis in CHC and NAFLD assessed cross-sectionally (odds ratio = 1.39, 95% confidence interval 1.04-1.87, and odds ratio = 1.62, 95% confidence interval 1.03-2.52, respectively; P < 0.03 for both), but had no effect on fibrosis progression in 1174 patients with CHC and a known duration of infection. Conclusion: The TM6SF2 E167K substitution promotes steatosis and lipid abnormalities in part by altering TM6SF2 and microsomal triglyceride transfer protein expression and differentially impacts CHC and chronic hepatitis B viral load, while effects on fibrosis are marginal

    The Multifunctional Building of Passive Standard

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    Import 26/02/2015Tato diplomová práce je zaměřena na vyprojektování multifunkčního domu, ve kterém bude zajištěno strojní větrání a zajištěno vytápění pomocí alternativního zdroje tepla. Multifunkční dům podsklepený a má čtyři nadzemní podlaží s pochozí terasou. Objekt je navržen ze sortimentu firmy Porotherm. Funkčně je navržen tak, že v prvním podzemním podlaží se nachází technické zázemí a kóje bytů, první nadzemní podlaží tvoří dvě nezávislé prodejní plochy. Ve druhém patře jsou umístěny kancelářské prostory. Druhou horní polovinu objektu , třetí a čtvrté nadzemní podlaží, tvoří bytové jednotky. Základním kamenem pro nutnou výměnu vzduchu v objektu jsou tři vzduchotechnické systémy, které se starají o dodávku a výměnu vzduchu ve třech celcích. První celkem je jednotka pro prodejní plochy v prvním nadzemním podlaží a kancelářské prostory ve druhém nadzemním podlaží. Druhá jednotka má na starosti byty ve třetím a čtvrtém podlaží a poslední, třetí, jednotka zajišťuje přívod čerstvého vzduchu do společných prostor a odvod odpadního vzduchu do exteriéru. Všechny jednotky jsou vybaveny rekuperátorem. V objektu je také řešeno vytápění pomocí alternativních zdrojů. Jako alternativní zdroje energie jsou použity tepelné čerpadlo vzduch – voda a solární kolektory. Tepelné čerpadlo se stará o pokrytí tepelných ztrát prostupem, větráním a přípravou teplé vody. Solární kolektory umístěné na terase pomáhají s ohřevem teplé vody v objektu.This Master thesis is focused on the projection Multifunctional building, which will ensure mechanical ventilation and heating ensured by using alternative heat sources. Multifunctional building basement and has four floors with walkable terrace. The building is designed from company Porotherm. Functionally, it is designed so that on the first floor there is a technical background and cubicle apartments, first floor consists of two independent sales area. On the second floor there are office spaces. The second half of the upper house, the third and fourth floors, consists of residential units. The cornerstone for the necessary air exchange in the building are three air handling systems that are responsible for the delivery and exchange of air in three units. The first is the total unit sales area on the first floor and office space on the second floor. The second unit is in charge of flats in the third and fourth floors and the last third unit provides fresh air to the common area and the exhaust to the exterior. All units are equipped with a recuperator. There is also heating solutions using alternative sources. As alternative energy sources are used heat pump air - water and solar collectors. The heat pump takes care of the cover heat losses through transmission, ventilation and hot water. Solar collectors located on the terrace help with hot water in the building.Prezenční229 - Katedra prostředí staveb a TZBvýborn

    Production of specific antibodies against SARS-coronavirus nucleocapsid protein without cross reactivity with human coronaviruses 229E and OC43

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    Severe acute respiratory syndrome (SARS) is a life-threatening disease for which accurate diagnosis is essential. Although many tools have been developed for the diagnosis of SARS, false-positive reactions in negative sera may occur because of cross-reactivity with other coronaviruses. We have raised polyclonal and monoclonal antibodies (Abs) using a recombinant form of the SARS virus nucleocapsid protein. Cross-reactivity of these anti-SARS Abs against human coronavirus (HCoV) 229E and HCoV OC43 were determined by Western blotting. The Abs produced reacted with recombinant SARS virus nucleocapsid protein, but not with HCoV 229E or HCoV OC43

    Flow characteristics and intrinsic workability of IN718 superalloy

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    This study focuses on deformation characteristics of superalloy IN718 by formulation of a new flowstress model and detailed evaluation of intrinsic workability through the generation of three-dimensional (3D) processing maps with the support of optical microstructural observations. Based on thermomechanical simulation tests using a Gleeble-1500 machine, the flow stress model for superalloy IN718 was built and the flow stress throughout the entire deformation process was described by a peak stress only depending on Zener–Hollomon parameter and strain. The developed model exhibited the strain softening due to dynamic recrystallization (DRX). The intrinsic workability was further investigated by constructing 3D processing maps. The 3D processing maps described the variations of the efficiency of power dissipation and flow instability domains as a function of strain rate, temperature and strain, from which the favourite deformation conditions for thermomechanical processing of IN718 can be established

    In vivo alternative testing with zebrafish in ecotoxicology

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    Although rodents have previously been used in ecotoxicological studies, they are expensive, time-consuming, and are limited by strict legal restrictions. The present study used a zebrafish (Danio rerio) model and generated data that was useful for extrapolating toxicant effects in this system to that of humans. Here we treated embryos of the naive-type as well as a transiently transfected zebrafish liver cell line carrying a plasmid (phAhRE-EGFP), for comparing toxicity levels with the well-known aryl hydrocarbon receptor (AhR)-binding toxicants: 3,3',4,4',5-pentachlorobiphenyl (PCB126), 2,3,7,8-tetrachlorodibenzo-p-dioxin, and 3-methylcholanthrene. These toxicants induced a concentration-dependent increase in morphological disruption, indicating toxicity at early life-stages. The transient transgenic zebrafish liver cell line was sensitive enough to these toxicants to express the CYP1A1 regulated enhanced green fluorescent protein. The findings of this study demonstrated that the zebrafish in vivo model might allow for extremely rapid and reproducible toxicological profiling of early life-stage embryo development. We have also shown that the transient transgenic zebrafish liver cell line can be used for research on AhR mechanism studies
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