• Steel and Composite Structures
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• v.42 no.4
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• pp.501-511
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• 2022

Earthquake Resistant Design Philosophy seeks (a) no damage, (b) no significant structural damage, and (c) significant structural damage but no collapse of normal buildings, under minor, moderate and severe levels of earthquake shaking, respectively. A procedure is proposed for seismic design of low-rise reinforced concrete special moment frame buildings, which is consistent with this philosophy; buildings are designed to be ductile through appropriate sizing and reinforcement detailing, such that they resist severe level of earthquake shaking without collapse. Nonlinear analyses of study buildings are used to determine quantitatively (a) ranges of design parameters required to assure the required deformability in normal buildings to resist the severe level of earthquake shaking, (b) four specific limit states that represent the start of different structural damage states, and (c) levels of minor and moderate earthquake shakings stated in the philosophy along with an extreme level of earthquake shaking associated with the structural damage state of no collapse. The four limits of structural damage states and the three levels of earthquake shaking identified are shown to be consistent with the performance-based design guidelines available in literature. Finally, nonlinear analyses results are used to confirm the efficacy of the proposed procedure.

• Journal of Life Science
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• v.26 no.6
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• pp.633-639
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• 2016

Biomaterials including polymer, metal, ceramic, and composite have been widely applied for medical uses as medical fibers, artificial blood vessels, artificial joints, implants, soft tissue, and plastic surgery materials owing to their physicochemical properties. However, the biocompatibility and toxicity for film- and plate-form biomaterials is difficult to measure in mammalian cells because there is no appropriate incubation system. To solve these problems, we developed a novel mammalian cell culture system consisting of a silicone ring, top panel, and bottom panel and we applied two polymer films (PF) and one metal plate (MP). This system was based on the principal of sandwiching a test sample between the top panel and the bottom panel. Following the assembly of the culture system, SK-MEL-2 cells were seeded onto Styela Clava Tunic (SCT)-PF, NaHCO₃-added SCT (SCTN)-PF, and magnesium MP (MMP) and incubated at 37℃ for 24 hr and 48 hr. An MTT assay revealed that cell viability was maintained at a normal level in the SCT-PF culture group at 24 or 48 hr, although it rapidly decreased in the SCTN-PF culture group at 48 hr. Furthermore, the cell viability in the MMP culture group was very similar to that of the control group after incubation for 24 hr and 48 hr. Together, these results suggest the sandwich-type mammalian culture system developed here has the potential for the evaluation of the biocompatibility and toxicity of cells against PF- and MP-form biomaterials.

• Fire Science and Engineering
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• v.31 no.6
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• pp.33-39
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• 2017

Composite panel refers to the particular plywood produced in a way of stacking the different kinds of material in sandwich form and adhering them using adhesives and is widely used as building material for its constructability and cost efficiency. But as the surface is finished with steel plate, fire extinguishing agent cannot reach to the core material because of such steel plate on surface which causes the difficulties in suppressing the fire as well as in fire-fighting activities due to collapse. This study, to deal with such problem, is intended to set the fire pipe in core material to prevent the fire from spreading and in a bid to achieve this using minimized fire water, water supply test device was fabricated to estimate the required water flow of fire extinguisher and consequently, optimal water flow (0.5 L/min) was determined through a full-scale fire test.

• Restorative Dentistry and Endodontics
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• v.29 no.5
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• pp.479-484
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• 2004

Immunoinhibitory protein extracted from sonicated Treponema denticola have been shown to suppress cell cycle progression of human lymphocytes. To study in detail about the effect of this microorganism on the function of lymphocytes. we investigated the levels of Interleukin-2 (IL-2) and Interleukin-4 (IL-4) production by T lymphocytes before and after the addition of $12.5{\;}\mu\textrm{g}/ml$ T. denticola sonicated extracts. In this study. levels of IL-2 and IL-4 produced from T cells pretreated with sonicated extracts were evaluated by using the quantitative sandwich enzyme immunoassay technique. In response to phytohemagglutinin (PHA) stimulation. T cell produced increased levels of IL-2 and IL-4. However. the expressions of both cytokines were significantly inhibited when PHA activated-T cells were pre-exposed to sonicated T. denticola extracts (p < 0.05). These findings suggest that the T. denticola sonicated extracts induced-immunosuppression in Th1 and Th2 cell functions could be a part of the pathogenic mechanism of the endodontic failure associated with this microorganism.