211 research outputs found

    X-ray Irradiation Induced Discharge of Spherical Void in Epoxy Resin

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    It is crucial for proper insulation design of cast resin transformer to consider voids and delamination which might exist in cast molding process and/or under long-term operation because of several surface boundaries between resin and conductor. Should such defects in the insulation system exist, it would lead to reduction of the life of the apparatus. In this report, we investigate the relation between the void size and apparent charge of partial discharge (PD) occurring in a model simulating the insulation system of cast resin transformer. It is also important to determine necessary PD detection sensitivity of PD test in a factory as well as in a field. In addition, we investigate X-ray irradiation induced discharge of spherical void in epoxy resin. Physical consideration of the effect of X-ray irradiation on void discharges in epoxy resin was also made. Time lag of void discharges in epoxy resin was also made with attenuation of X-ray irradiation dose considered.2011 Electrical Insulation Conference (EIC), 5-8 June 2011, Annapolis, M

    Interplay of a non-conjugative integrative element and a conjugative plasmid in the spread of antibiotic resistance via suicidal plasmid transfer from an aquaculture Vibrio isolate

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    The capture of antimicrobial resistance genes (ARGs) by mobile genetic elements (MGEs) plays a critical role in resistance acquisition for human-associated bacteria. Although aquaculture environments are recognized as important reservoirs of ARGs, intra- and intercellular mobility of MGEs discovered in marine organisms is poorly characterized. Here, we show a new pattern of interspecies ARGs transfer involving a ‘non-conjugative’ integrative element. To identify active MGEs in a Vibrio ponticus isolate, we conducted whole-genome sequencing of a transconjugant obtained by mating between Escherichia coli and Vibrio ponticus. This revealed integration of a plasmid (designated pSEA1) into the chromosome, consisting of a self-transmissible plasmid backbone of the MOBH group, ARGs, and a 13.8-kb integrative element Tn6283. Molecular genetics analysis suggested a two-step gene transfer model. First, Tn6283 integrates into the recipient chromosome during suicidal plasmid transfer, followed by homologous recombination between the Tn6283 copy in the chromosome and that in the newly transferred pSEA1. Tn6283 is unusual among integrative elements in that it apparently does not encode transfer function and its excision barely generates unoccupied donor sites. Thus, its movement is analogous to the transposition of insertion sequences rather than to that of canonical integrative and conjugative elements. Overall, this study reveals the presence of a previously unrecognized type of MGE in a marine organism, highlighting diversity in the mode of interspecies gene transfer

    Interplay of a non-conjugative integrative element and a conjugative plasmid in the spread of antibiotic resistance via suicidal plasmid transfer from an aquaculture Vibrio isolate

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    <div><p>The capture of antimicrobial resistance genes (ARGs) by mobile genetic elements (MGEs) plays a critical role in resistance acquisition for human-associated bacteria. Although aquaculture environments are recognized as important reservoirs of ARGs, intra- and intercellular mobility of MGEs discovered in marine organisms is poorly characterized. Here, we show a new pattern of interspecies ARGs transfer involving a ‘non-conjugative’ integrative element. To identify active MGEs in a <i>Vibrio ponticus</i> isolate, we conducted whole-genome sequencing of a transconjugant obtained by mating between <i>Escherichia coli</i> and <i>Vibrio ponticus</i>. This revealed integration of a plasmid (designated pSEA1) into the chromosome, consisting of a self-transmissible plasmid backbone of the MOB<sub>H</sub> group, ARGs, and a 13.8-kb integrative element Tn<i>6283</i>. Molecular genetics analysis suggested a two-step gene transfer model. First, Tn<i>6283</i> integrates into the recipient chromosome during suicidal plasmid transfer, followed by homologous recombination between the Tn<i>6283</i> copy in the chromosome and that in the newly transferred pSEA1. Tn<i>6283</i> is unusual among integrative elements in that it apparently does not encode transfer function and its excision barely generates unoccupied donor sites. Thus, its movement is analogous to the transposition of insertion sequences rather than to that of canonical integrative and conjugative elements. Overall, this study reveals the presence of a previously unrecognized type of MGE in a marine organism, highlighting diversity in the mode of interspecies gene transfer.</p></div

    Mechanistic insights into intramembrane proteolysis by E. coli site-2 protease homolog RseP

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    細胞膜の中ではたらく特殊なタンパク質分解酵素の構造を解明 --細菌感染症の新たな治療法の開発へ期待--. 京都大学プレスリリース. 2022-08-25.Site-2 proteases are a conserved family of intramembrane proteases that cleave transmembrane substrates to regulate signal transduction and maintain proteostasis. Here, we elucidated crystal structures of inhibitor-bound forms of bacterial site-2 proteases including Escherichia coli RseP. Structure-based chemical modification and cross-linking experiments indicated that the RseP domains surrounding the active center undergo conformational changes to expose the substrate-binding site, suggesting that RseP has a gating mechanism to regulate substrate entry. Furthermore, mutational analysis suggests that a conserved electrostatic linkage between the transmembrane and peripheral membrane-associated domains mediates the conformational changes. In vivo cleavage assays also support that the substrate transmembrane helix is unwound by strand addition to the intramembrane β sheet of RseP and is clamped by a conserved asparagine residue at the active center for efficient cleavage. This mechanism underlying the substrate binding, i.e., unwinding and clamping, appears common across distinct families of intramembrane proteases that cleave transmembrane segments

    Neutron capture cross section measurements of 120

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    Preliminary neutron capture cross section of 120Sn, 122Sn and 124Sn were obtained in the energy range from 20 meV to 4 keV with the array of germanium detectors in ANNRI at MLF,J-PARC. The results of 120Sn, 122Sn and 124Sn were obtained by normalizing the relative cross sections to the data in JENDL-4.0 at the largest 426.7-, 107.0- and 62.05-eV resonances, respectively. The 67.32- and 150-eV resonances for 120Sn and the 579- and 950-eV resonances for 124Sn which are listed in JENDL-4.0 and/or ENDF/B VII.1 were not observed

    Clarifying the Destructive Influence of Gravitation Set in Infusion Pump

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    Import 22/07/2015Infuzní léčba je v současnosti jedním z nejběžnějších úkonů, prováděných ve zdravotnických zařízeních, a nachází uplatnění v širokém spektru případů. Samotný proces léčby může být uskutečněn dvěma způsoby – gravitační infuzí a použitím volumetrické infuzní pumpy. Princip infuze řízené volumetrickou pumpou klade specifické nároky na vlastnosti užívaných infuzních setů, přičemž pro zajištění důležité přesnosti průtoku je nezbytné dbát na určení daného setu pro použití s tlakovou metodou. V běžném zdravotnickém prostředí však existuje řada rizikových faktorů, jejichž vlivem může dojít k porušení této podmínky kompatibility a následnému použití volumetrické pumpy s nevhodnou administrativní soupravou, určenou pouze pro gravitační infuzi. Záměrem první části této práce je, na základě známých poznatků o negativních vlivech činnosti pumpy na přesnost léčby a o mechanických vlastnostech infuzních setů, teoreticky stanovit možné destrukční vlivy čerpadla infuzní pumpy na materiál gravitačního setu. Cílem druhé části je pokusit se prokázat negativní dopad mechanického namáhání gravitačního setu v infuzní pumpě na přesnost dávkování a vlastnosti materiálu použitého setu pomocí experimentálně získaných dat.Intravenous therapy is currently one of the most common operations performed in health care facilities, finding its use in a wide range of cases. The particular process of treatment can be implemented in two ways - using gravity-fed infusion and by use of volumetric infusion pump. The principle of infusion controlled by a volumetric pump lays specific demands on the quality of the infusion sets in use. When warranting the flow rate accuracy it is necessary to ensure suitability of the set for use with the pressure method. However, there are a number of risk factors in common medical situations, whose influence may lead to violating the terms of compatibility and the subsequent use of a volumetric pump with an improper administrative set made only for gravity-fed infusion. The aim of the first part of this work is the theoretical determination of the possible destructive effects of the infusion pump to the material of a gravity-fed administration set based on the evidence about the negative impacts of the pump on the flow rate accuracy and mechanical characteristics of the infusion sets. The goal of the second part is an effort to proof the negative impact of the mechanical stress of a gravity set in an infusion pump to dosage accuracy and the material properties of the used set through experimental data.450 - Katedra kybernetiky a biomedicínského inženýrstvívýborn

    The first success of glass eel production in the world: basic biology on fish reproduction advances new applied technology in aquaculture

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    The eel has long been esteemed as an important food fish in the world, especially in Japan, and has been used as an experimental fish for many fields of fish physiology. However, the decreases in eel resources have been a serious concern in recent years. The catches of glass eels as seedlings for aquaculture have shown a long-term decrease in both Europe and East Asia. To increase eel resources, the development of techniques for artificial induction of maturation and spawning and rearing their larvae have been eagerly desired. Recent progress of reproductive physiology of fish, especially mechanisms of oocyte maturation and ovulation in female and of spermatozoa maturation in male, facilitate to establish techniques for hormonal induction of maturation and spawning in sexually immature eels. With persistent effort to development of rearing techniques of larvae, we have first succeeded to produce glass eel. These applied techniques are may contribute to understand the basic reproductive physiology of the eel

    Research and development for accuracy improvement of neutron nuclear data on minor actinides

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    To improve accuracy of neutron nuclear data on minor actinides, a Japanese nuclear data project entitled “Research and development for Accuracy Improvement of neutron nuclear data on Minor ACtinides (AIMAC)” has been implemented. Several independent measurement techniques were developed for improving measurement precision at J-PARC/MLF/ANNRI and KURRI/LINAC facilities. Effectiveness of combining the independent techniques has been demonstrated for identifying bias effects and improving accuracy, especially in characterization of samples used for nuclear data measurements. Capture cross sections and/or total cross sections have been measured for Am-241, Am-243, Np-237, Tc-99, Gd-155, and Gd-157. Systematic nuclear data evaluation has also been performed by taking into account the identified bias effect. Highlights of the AIMAC project are outlined
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