• Journal of Navigation and Port Research
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• v.39 no.4
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• pp.285-291
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• 2015

Exposure to cold sea water can be life-threatening to the drowned individual. Although appropriate life jacket can be usually be provided for the buoyance at the drowning accident, heat loss can make the drowned individual experience the hypothermia. Inflatable life jackets filled with inflatable air pocket can increase the thermal protection as well as the buoyancy force. Because it is important to know how the human body behaves unde the different life jacket, present study compares the thermal insulation capacity of solid type life jacket with that of inflatable life jacket. In order to represent the insulation capacity of life jacket, thermal resistance is estimated based on the assumption of steady-state. Also, a transient three-dimensional thermal distribution of the thigh is analyzed by using finite element method implementing the Pennes bioheat equation. The finite element model is a segmental, multi-layered representation of the body section which considers the heat conduction within tissue, bone, fat and local blood flow rate.

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.38-44
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• 2005

Infection with hepatitis B virus (HBV) is a major health problem worldwide. Although a tremendous amount has been known about HBV, there have been obstacles in the study of HBV due to the narrow host range of HBV limited to humans and primates. In the present study, we investigated the susceptibility to HBV infection of mouse hepatoma cell line, Hepa-1c1c7. In addition, based on that human hepatocytes infected by HBV increase the expression of the pro-inflammatory cytokine TNF-a, the inducibility of TNF-a expression by HBV in the cells was determined. HBV surface antigen (HBsAg) secretion was measured by the microparticle enzyme immunoassay and steady state mRNA expression was analyzed by quantitative competitive RT-PCR. Transient transfection of Hepa-1c1c7 cells with HBV expression vector resulted in a dose-dependent induction of TNF-a expression. Infection of Hepa-1c1c7 cells with the serum of HBV carrier also increased TNF-a mRNA expression. Both in the transfected and infected cells, HBV mRNA was expressed and significant HBsAg secretion was detected. There was no significant variation in $\beta-actin$ mRNA expression by HBV. These results demonstrate that HBV is infectious to Hepa-lc1c7 in vitro and the viral infection induces TNF-a expression, which suggests that Hepa-lc1c7, a mouse hepatoma cell line, may be a possible model system for analysis of various molecular aspects of HBV infection.