252 research outputs found

    Development of Highly Reliable Power and Communication System for Essential Instruments Under Severe Accidents in NPP

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    AbstractThis article proposes a highly reliable power and communication system that guarantees the protection of essential instruments in a nuclear power plant under a severe accident. Both power and communication lines are established with not only conventional wired channels, but also the proposed wireless channels for emergency reserve. An inductive power transfer system is selected due to its robust power transfer characteristics under high temperature, high pressure, and highly humid environments with a large amount of scattered debris after a severe accident. A thermal insulation box and a glass-fiber reinforced plastic box are proposed to protect the essential instruments, including vulnerable electronic circuits, from extremely high temperatures of up to 627°C and pressure of up to 5 bar. The proposed wireless power and communication system is experimentally verified by an inductive power transfer system prototype having a dipole coil structure and prototype Zigbee modules over a 7-m distance, where both the thermal insulation box and the glass-fiber reinforced plastic box are fabricated and tested using a high-temperature chamber. Moreover, an experiment on the effects of a high radiation environment on various electronic devices is conducted based on the radiation test having a maximum accumulated dose of 27 Mrad

    Current Status of Trace Metal Pollution in Soils Affected by Industrial Activities

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    There is a growing public concern over the potential accumulation of heavy metals in soil, owing to rapid industrial development. In an effort to describe the status of the pollutions of soil by industrial activities, relevant data sets reported by many studies were surveyed and reviewed. The results of our analysis indicate that soils were polluted most significantly by metals such as lead, zinc, copper, and cadmium. If the dominant species are evaluated by the highest mean concentration observed for different industry types, the results were grouped into Pb, Zn, Ni, Cu, Fe, and As in smelting and metal production industries, Mn and Cd in the textile industry, and Cr in the leather industry. In most cases, metal levels in the studied areas were found to exceed the common regulation guideline levels enforced by many countries. The geoaccumulation index (Igeo), calculated to estimate the enrichment of metal concentrations in soil, showed that the level of metal pollution in most surveyed areas is significant, especially for Pb and Cd. It is thus important to keep systematic and continuous monitoring of heavy metals and their derivatives to manage and suppress such pollution

    Enhanced cardiac expression of two isoforms of matrix metalloproteinase-2 in experimental diabetes mellitus.

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    BackgroundDiabetic cardiomyopathy (DM CMP) is defined as cardiomyocyte damage and ventricular dysfunction directly associated with diabetes independent of concomitant coronary artery disease or hypertension. Matrix metalloproteinases (MMPs), especially MMP-2, have been reported to underlie the pathogenesis of DM CMP by increasing extracellular collagen content.PurposeWe hypothesized that two discrete MMP-2 isoforms (full length MMP-2, FL-MMP-2; N-terminal truncated MMP-2, NTT-MMP-2) are induced by high glucose stimulation in vitro and in an experimental diabetic heart model.MethodsRat cardiomyoblasts (H9C2 cells) were examined to determine whether high glucose can induce the expression of the two isoforms of MMP-2. For the in vivo study, we used the streptozotocin-induced DM mouse heart model and age-matched controls. The changes of each MMP-2 isoform expression in the diabetic mice hearts were determined using quantitative real-time polymerase chain reaction (qRT-PCR). Immunohistochemical stains were conducted to identify the location and patterns of MMP-2 isoform expression. Echocardiography was performed to compare and analyze the changes in cardiac function induced by diabetes.ResultsQuantitative RT-PCR and immunofluorescence staining showed that the two MMP-2 isoforms were strongly induced by high glucose stimulation in H9C2 cells. Although no definite histologic features of diabetic cardiomyopathy were observed in diabetic mice hearts, left ventricular systolic dysfunction was determined by echocardiography. Quantitative RT-PCR and IHC staining showed this abnormal cardiac function was accompanied with the increases in the mRNA levels of the two isoforms of MMP-2 and related to intracellular localization.ConclusionTwo isoforms of MMP-2 were induced by high glucose stimulation in vitro and in a Type 1 DM mouse heart model. Further study is required to examine the role of these isoforms in DM CMP

    The potent protective effect of wild ginseng (Panax ginseng C.A. Meyer) against benzo[alpha]pyrene-induced toxicity through metabolic regulation of CYP1A1 and GSTs

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    Wild Panax ginseng C.A. Meyer (WG) is a well-known medicinal herb. In this study, the protective effects of a water extract from the root of WG on benzo[alpha]pyrene (BP)-induced hepatotoxicity and the mechanism of these effects were investigated for the first time. The effects of WG on liver toxicities induced by BP were assessed by blood biochemical and histopathological analyses. BP caused severe liver injury in rats, as indicated by elevated plasma ALT, AST and LPO levels. Pretreatment with WG for 4 weeks completely abrogated increases in the ALT, AST and LPO levels when challenged with BP. Reductions in GSH content and GST activity by BP were reversed by WG. These protective effects of WG against BP-induced toxicity were consistent with the results of histopathological examinations. We next examined the effects of WG on the gene expression of the enzymes that metabolize BP in H4IIE cells. CYP1A1 mRNA and protein expression were increased by BP. WG moderately inhibited BP-induced CYP1A1 gene expression. Moreover, GSTA2, GSTA3 and GSTM2 gene expressions were significantly increased by WG through the Nrf2/antioxidant responsive element pathway for enzyme induction. In summary, WG is efficacious in protecting against BP-induced hepatotoxicity as results of metabolic regulations through both the inhibition of metabolic enzyme activation and the enhancement of electrophilic detoxification, implying that WG should be considered a potential chemopreventive agent

    Detection of sarcocystic infection in a wild rodent (Apodemus agrarius chejuensis) captured on Jeju island

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    Sarcocystis spp is a causative agent of sarcocystosis. They have a characteristic life cycle infecting both prey and predator. Sarcocystis can cause myositis, atrophy of the adjacent cells and abortion in cattle. In mice, sarcocystosis causes mild cellular reactions without clinical disease. Severe haemorrhage and abortion were also reported. For monitoring the disease in wild rodents of the Korean peninsula, we captured Apodemus agrarius chejuensis on Jeju island and examined the specimen histopathologically. Intramuscular cysts were found and diagnosed as Sarcocystis. Sarcocystic infection has been reported in worldwide. There have been many reported infections in cattle and pigs in Korea. To our knowledge, this is the first report of Sarcocystis in Apodemus agrarius chejuensis captured in Korea

    The Relationship Between Coronary Artery Calcification and Bone Mineral Density in Patients According to Their Metabolic Syndrome Status

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    Background and Objectives: The extent of coronary artery calcification (CAC) is closely related to total atherosclerotic plaque burden. However, the pathogenesis of CAC is still unclear. Conditions such as diabetes mellitus, renal failure, smoking, and chronic inflammation have been suggested to link vascular calcification and bone loss. In the present study, we hypothesized that bone loss can contribute to the pathogenesis of CAC in patients with the chronic inflammatory condition that accompanies metabolic syndrome (MetS). The objective of this study was to investigate the relationship between CAC and bone mineral density (BMD) in patients with MetS and in patients without MetS, by using coronary multidetector-row computed tomography (MDCT). Subjects and Methods: Data from 395 consecutive patients was analyzed retrospectively. From the MDCT database, only those patients who underwent both coronary MDCT and dual-energy X-ray absorptiometry within an interval of one month, were selected. The presence of MetS was determined by the updated criteria as defined by the Third Adult Treatment Panel Report of the National Cholesterol Education Program. Results: In patients with MetS, a significant correlation was found between CAC and age {odds ratio (OR)=1.139, 95% confidence interval (CI) 1.080 to 1.201, p<0.001}, CAC and male sex (OR=3.762, 95% CI 1.339 to 10.569, p=0.012), and CAC and T-score of L-spine (OR=0.740, 95% CI 0.550 to 0.996, p=0.047) using a forward multiple logistic regression analysis model including clinical variables of gender, age, lipid profile, body mass index, diabetes mellitus, hypertension, smoking, and BMD. But in patients without MetS, BMD by itself was not found to contribute to CAC. Conclusion: BMD was inversely correlated with CAC only in patients with MetS. This finding suggests that low BMD accompanied by MetS, may have significant clinical implications
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