17 research outputs found

    Experimental and numerical investigation on the structural performance of the tensioning air beam system

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    An experimental and numerical study on the structural performance of the tensioning air beam system (TABS) is presented. TABS is a hybrid structural system consisting of a membrane air beam, steel frames and cable struts. This system has the advantage of reduced self-weight and is easy to construct while it can improve the load bearing capacity of membrane structures. It maximizes the structural capacities of individual elements, thus can be considered as a very effective system in terms of both structural and economical aspects. In this paper, a test was carried out to examine the structural performance of TABS under different membrane pressure conditions. The material properties of the air beam were obtained from the results of two membrane tensile strength tests, which were performed prior to the main test. A simple numerical model was proposed to predict the structural behavior of TABS and its validity was evaluated by comparing its results with the test values

    Analysis of Yield of Eleutherosides B and E in Acanthopanax divaricatus

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    An analysis of the yield of eleutherosides B and E in Acanthopanax divaricatus and A. koreanum was performed using high performance liquid chromatography to evaluate production by different cultivation methods. In A. divaricatus and A. koreanum, the total content of eleutherosides B and E was 2.466–7.360 mg/g varying by plant section, 3.886–11.506 mg/g by pinching site, 3.655–10.083 mg/g by planting time, and 3.652–10.108 mg/g by fertilizer ratio. Thus the total content of eleutherosides B and E in A. divaricatus and A. koreanum differed depending on cultivation methods. These results present useful information for high eleutheroside content applications in A. divaricatus and A. koreanum. This information can affect selection of plant section and cultivation methods for nutraceutical, pharmaceutical, and cosmeceutical material development

    Enhanced Metal Coating Adhesion by Surface Modification of 3D Printed PEKKs

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    PEKK (polyether-ketone-ketone) polymer has been actively studied in applying electronic devices in satellites owing to its excellent light weight and thermal resistance. However, the limitation of metal coating to form on the PEKK surface is due to the high-volume resistivity and surface resistance. Here, we have investigated the correlations between the chemical treatment of the surface and adhesion strength between polymer–metal coating. Three-dimensional printed PEKK objects were manufactured and nickel was deposited on the surface by electroless plating. As the concentration of H2SO4 increased from 12.5 to 14.3 mol/L, the pore diameter showed a tendency to increase. However, as growing pore induced connecting each other, the pore size re-decreased from 15.1 to 18.0 mol/L. To control pore size and uniformity, we investigated the pore diameter of 3D printed PEKK as a function of treatment time and temperature. Uniform pores were observed at a temperature of 50 °C which were formed after 10 min and the average pore size was 0.28 μm. After H2SO4 swelling, samples were re-treated in the KMnO4-H3PO4 etching system for the hydrophilic group. KMnO4 broken C=C bonding and generated hydrophilic groups such as -COOH and -OH, the contact angle decreased from 64.7 to 51.1° compared with H2SO4 swelling. XPS survey spectra confirmed that not only breaking C=C bonding but also increasing hydrophilicity due to -OH, -C-, -SO3 and the catalyst absorption of Pd was improved. As a result of adhesive strength by ASTM D3359, compared with the H2SO4 swelling, the KMnO4-H3PO4 etching system showed 5B which is the best result in standard test methods by adhesive tape test and peeling amount on the tape was less than 0.01%

    The costs of hepatitis A infections in South Korea

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    OBJECTIVES: The incidence of hepatitis A infections among young adults has recently increased in South Korea. Although universal vaccination has often been suggested to mitigate the problem, its rationale has not been well-understood. Estimating the societal costs of hepatitis A infections might support the development of intervention strategies. METHODS: We classified hepatitis A infections into eight clinical pathways and estimated the number of occurrences and cost per case for each clinical pathway using claim data from National Health Insurance and several national surveys as well as assumptions based on previous studies. To determine the total costs of a hepatitis A infection, both direct and indirect costs were estimated. Indirect costs were estimated using the human-capital approach. All costs are adjusted to the year 2008. RESULTS: There were 30,240 identified cases of hepatitis A infections in 2008 for a total cost of 80,873 million won (2.7 million won per case). Direct and indirect costs constituted 56.2% and 43.8% of the total costs, respectively. People aged 20-39 accounted for 71.3% of total cases and 74.6% of total costs. Medical costs per capita were the lowest in the 0-4 age group and highest in the 20-29 age group. CONCLUSIONS: This study could provide evidence for development of cost-effective interventions to control hepatitis A infections. But the true costs including uncaptured and intangible costs of hepatitis A infections might be higher than our results indicate

    Development and Validation of SNP and InDel Markers for Pod-Shattering Tolerance in Soybean

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    Pod-shattering causes a significant yield loss in many soybean cultivars. Shattering-tolerant cultivars provide the most effective approach to minimizing this loss. We developed molecular markers for pod-shattering and validated them in soybeans with diverse genetic backgrounds. The genes Glyma.16g141200, Glyma.16g141500, and Glyma.16g076600, identified in our previous study by quantitative trait locus (QTL) mapping and whole-genome resequencing, were selected for marker development. The whole-genome resequencing of three parental lines (one shattering-tolerant and two shattering-susceptible) identified single nucleotide polymorphism (SNP) and/or insertion/deletion (InDel) regions within or near the selected genes. Two SNPs and one InDel were converted to Kompetitive Allele-Specific PCR (KASP) and InDel markers, respectively. The accuracy of the markers was examined in the two recombinant inbred line populations used for the QTL mapping, as well as the 120 varieties and elite lines, through allelic discrimination and phenotyping by the oven-drying method. Both types of markers successfully discriminated the pod shattering-tolerant and shattering-susceptible genotypes. The prediction accuracy, which was as high as 90.9% for the RILs and was 100% for the varieties and elite lines, also supported the accuracy and usefulness of these markers. Thus, the markers can be used effectively for genetic and genomic studies and the marker-assisted selection for pod-shattering tolerance in soybean

    Genome-Wide Transcriptome and Metabolome Analyses Provide Novel Insights and Suggest a Sex-Specific Response to Heat Stress in Pigs

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    Heat stress (HS) negatively impacts pig production and swine health. Therefore, to understand the genetic and metabolic responses of pigs to HS, we used RNA-Seq and high resolution magic angle spinning (HR-MAS) NMR analyses to compare the transcriptomes and metabolomes of Duroc pigs (n = 6, 3 barrows and 3 gilts) exposed to heat stress (33 °C and 60% RH) with a control group (25 °C and 60% RH). HS resulted in the differential expression of 552 (236 up, 316 down) and 879 (540 up, 339 down) genes and significant enrichment of 30 and 31 plasma metabolites in female and male pigs, respectively. Apoptosis, response to heat, Toll-like receptor signaling and oxidative stress were enriched among the up-regulated genes, while negative regulation of the immune response, ATP synthesis and the ribosomal pathway were enriched among down-regulated genes. Twelve and ten metabolic pathways were found to be enriched (among them, four metabolic pathways, including arginine and proline metabolism, and three metabolic pathways, including pantothenate and CoA biosynthesis), overlapping between the transcriptome and metabolome analyses in the female and male group respectively. The limited overlap between pathways enriched with differentially expressed genes and enriched plasma metabolites between the sexes suggests a sex-specific response to HS in pigs

    QTL Mapping and Candidate Gene Analysis for Pod Shattering Tolerance in Soybean (Glycine max)

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    Pod shattering is an important reproductive process in many wild species. However, pod shattering at the maturing stage can result in severe yield loss. The objectives of this study were to discover quantitative trait loci (QTLs) for pod shattering using two recombinant inbred line (RIL) populations derived from an elite cultivar having pod shattering tolerance, namely “Daewonkong”, and to predict novel candidate QTL/genes involved in pod shattering based on their allele patterns. We found several QTLs with more than 10% phenotypic variance explained (PVE) on seven different chromosomes and found a novel candidate QTL on chromosome 16 (qPS-DS16-1) from the allele patterns in the QTL region. Out of the 41 annotated genes in the QTL region, six were found to contain SNP (single-nucleotide polymorphism)/indel variations in the coding sequence of the parents compared to the soybean reference genome. Among the six potential candidate genes, Glyma.16g076600, one of the genes with known function, showed a highly differential expression levels between the tolerant and susceptible parents in the growth stages R3 to R6. Further, Glyma.16g076600 is a homolog of AT4G19230 in Arabidopsis, whose function is related to abscisic acid catabolism. The results provide useful information to understand the genetic mechanism of pod shattering and could be used for improving the efficiency of marker-assisted selection for developing varieties of soybeans tolerant to pod shattering
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