1,680 research outputs found

    Effectiveness of Electrical Heating for Improved Thermal Insulation of a Multi-layered Winter Clothing System

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    This paper investigated the impact of the distance of the heating unit from the body in a multi-layered winter clothing system on effective thermal insulation and heating efficiency. To identify changes in the thermal insulation and heating efficiency of electrical heating in different layers inside a winter clothing ensemble, a series of thermal manikin tests was conducted. A multi-layered winter ensemble with and without activation of a heating unit was tested on the thermal manikin under two different ambient temperature conditions (10°C and 5°C). Results show that the effective thermal insulation of test ensembles increased by 5-7 percent with the activation of the heating unit compared to that without the activation. The closer the heating unit to the body, the higher the effective thermal insulation was in both ambient temperature conditions. This trend was more significant at lower ambient temperature

    The diameter of the world wide web

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    Despite its increasing role in communication, the world wide web remains the least controlled medium: any individual or institution can create websites with unrestricted number of documents and links. While great efforts are made to map and characterize the Internet's infrastructure, little is known about the topology of the web. Here we take a first step to fill this gap: we use local connectivity measurements to construct a topological model of the world wide web, allowing us to explore and characterize its large scale properties.Comment: 5 pages, 1 figure, updated with most recent results on the size of the ww

    Synthetic chloride transporters with the binding mode observed in a ClC chloride channel

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    A series of synthetic molecules bearing the same hydrogen bonding mode observed in StClC were prepared and their transport ability of chloride ion across a lipid membrane was systematically optimized.close4

    The diagnosis of pulmonary tuberculosis: a Korean perspective

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    Despite global efforts to eliminate tuberculosis, the disease remains of huge global public health problem. Prompt and accurate diagnosis of pulmonary tuberculosis is essential to ensure appropriate therapy. Chest radiography, sputum smear microscopy, mycobacterial culture, and nucleic acid amplification test are essential diagnostic elements, and appropriate use of recently introduced molecular tests and chest computed tomography could improve the accuracy of early diagnosis

    A plausible mode of action of pseudin-2, an antimicrobial peptide from Pseudis paradoxa

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    AbstractThe search for new antibiotic agents is continuous, reflecting the continuous emergence of antibiotic-resistant pathogens. Among the new agents are the antimicrobial peptides (AMPs), which have the potential to become a leading alternative to conventional antibiotics. Studies for the mechanisms of action of the naturally occurring parent peptides can provide the structural and functional information needed for the development of effective new antibiotic agents. We therefore characterized pseudin-2, an AMP isolated from the skin of the South American paradoxical frog Pseudis paradoxa. We found that pseudin-2 organized to an aggregated state in aqueous solution, but that it dissociated into monomers upon binding to lipopolysaccharide (LPS), even though it did not neutralize LPS in Gram-negative bacteria. In addition, pseudin-2 assumed an α-helical structure in the presence of biological membranes and formed pores in both bacterial and fungal membranes, through which it entered the cytoplasm and tightly bound to RNA. Thus, the potent antimicrobial activity of pseudin-2 likely results from both the formation of pores capable of collapsing the membrane potential and releasing intracellular materials and its inhibition of macromolecule synthesis through its binding to RNA

    Evaluation of the pathogenicity of GJB3 and GJB6 variants associated with nonsyndromic hearing loss

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    AbstractA number of genes responsible for hearing loss are related to ion recycling and homeostasis in the inner ear. Connexins (Cx26 encoded by GJB2, Cx31 encoded by GJB3 and Cx30 encoded by GJB6) are core components of gap junctions in the inner ear. Gap junctions are intercellular communication channels and important factors that are associated with hearing loss. To date, a molecular genetics study of GJB3 and GJB6 as a causative gene for hearing loss has not been performed in Korea. This study was therefore performed to elucidate the genetic characteristics of Korean patients with nonsyndromic sensorineural hearing loss and to determine the pathological mechanism of hearing loss by analyzing the intercellular communication function of Cx30 and Cx31 variants. Sequencing analysis of the GJB3 and GJB6 genes in our population revealed a total of nine variants, including four novel variants in the two genes. Three of the novel variants (Cx31-p.V27M, Cx31-p.V43M and Cx-30-p.I248V) and two previously reported variants (Cx31-p.V84I and Cx30-p.A40V) were selected for functional studies using a pathogenicity prediction program and assessed for whether the mutations were located in a conserved region of the protein. The results of biochemical and ionic coupling tests showed that both the Cx31-p.V27M and Cx31-p.V84I variants did not function normally when each was expressed as a heterozygote with the wild-type Cx31. This study demonstrated that two variants of Cx31 were pathogenic mutations with deleterious effect. This information will be valuable in understanding the pathogenic role of GJB3 and GJB6 mutations associated with hearing loss
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