• 한국추진공학회:학술대회논문집
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• 한국추진공학회 1995년도 제5회 학술강연회논문집
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• pp.11-30
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• 1995

The ignition characteristics of a reactive solid with rough surface by constant heat flux were studied. The geometry of surface was represented by a set of identical protrusions having a shape of wedge based on the block of reactive solid. Several regimes of ignition were found, depending on the ratio of the protrusion length and the depth of the heated layer, formed in course of ignition process: 1) when the substance is ignited as the massive block, and the effect of roughness is not pronounced; 2) when ignited are the individual protrusions; and 3) in the intermediate region between the first two. Critical ignition conditions: ignition time and ignition criterion, are determined for the three regimes. The results are compared with the results for the one-dimensional ignition of the semi-infinite body. It is shown, that the effect of geometry on ignition results in the considerable reduction of ignition delay, and the amount of energy required for the successful ignition is less compared to the one- dimensional case.

• Nuclear Engineering and Technology
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• 제56권9호
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• pp.3942-3949
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• 2024

This study focuses on investigating the chemical degradation characteristics of cementitious barriers used in low-and intermediate-level radioactive waste repository by reactive transport modeling. The impact of the blending with supplementary cementitious materials (SCMs) in the barriers on the chemical degradation was evaluated to find the optimum barrier design. A number of different barrier designs were examined by replacing ordinary Portland cement (OPC) by SCMs (i.e., fly ash, silica fume, and blast-furnace slag). The simulation results showed that silica fume blended barrier has better durability against chemical degradation by rainwater compared to fly ash or blast-furnace slag blended barriers. In addition, the chemical durability of silica fume-based barrier increased with increasing replacement level up to about 20 %. It seems that the amount of formed calcium silicate hydrate (CSH) in the initial cement-based barrier highly affects the overall chemical durability. The newly developed reactive transport model demonstrated its capability for understanding the barrier performance and investigating the optimal design of the barrier system.

• Bulletin of the Korean Chemical Society
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• 제29권2호
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• pp.313-318
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• 2008

An enantioselective ring opening of racemic terminal epoxides has been achieved by using heterobimetallic cobalt salen complexes with variety of nucleophiles. They were proven to be highly enantioselective and reactive for the synthesis of valuable chiral building blocks in enantio-riched forms up to 98% ee.

• Bulletin of the Korean Chemical Society
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• 제10권6호
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• pp.543-546
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• 1989

The photocycloaddition reaction of khellin with several olefins has been investigated. The photocycloadducts are formed regioselectively on furanyl 4',5'-double bond of khellin probably due to the localization of excitation energy on the furanyl 4',5'-double bond in the reactive excited state. The photocycloaddition reaction proceeds through the excited triplet state and the same product was formed when khellin is irradiated with dimethylfumarate or dimethylmaleate indicating the formation of common intermediate. The quantum yields of photocycloadduct formation, fluorescence, and intersystem crossing are very sensitive to proton-donating ability of solvents.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.210.1-210.1
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• 2003

In this study, we investigated the effect of inhibition of proliferation and antioxidant effect on B16F10 murine melanoma cell. Also, we examined by MTT(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and intracellular reactive oxygen intermediate levels and the levels of catalase(CAT), superoxide dismutase (SOD), and glutathione peroxidase(GPX) an adaptive response of oxidative stress on B16F10 murine melanoma cell of pretreated with hydrogen peroxide. (omitted)

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.159.3-160
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• 2003

It has been known that quercetin is one of bioflavonid compounds and has anti-tumor effect by suppressing tumor growth in vitro and in vivo, including multiple biological effects by antioxidant and effective anti-inflammatory agent. The present study investigated whether quercetin can enhance antioxidant enzyme activity (glutathione proxidase: GPX, superoxide dismutase: SOD, catalase: CAT) and regulate the intracellular reactive oxygen intermediate levels on the B16F10 murine melanoma cells in the presensece of vitamin E, L-ascorbic acid (vitamin C) and reduced glutathione (GSH). (omitted)

• The Korean Journal of Physiology and Pharmacology
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• 제1권3호
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• pp.285-296
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• 1997

Injury to brain transforms resting astrocytes to their reactive form, the hallmark of which is an increase in glial fibrillary acidic protein (GFAP), the major intermediate filament protein of their cell type. The overall glial response after brain injury is referred to as reactive gliosis. Glial-neuronal interaction is important for neuronal migration, neurite outgrowth and axonal guidance during ontogenic development. Although much attention has been given to glial regulation of neuronal development and regeneration, evidences also suggest a neuronal influence on glial cell differentiation, maturation and function. The aim of the present study was to analyze the effects of glial-hippocampal neuronal co-culture on GFAP expression in the co-cultured astrocytes. The following antibodies were used for double immunostaining chemistry; mouse monoclonal antibodies for confirm neuronal cells, rabbit anti GFAP antibodies for confirm astrocytes. Primary cultured astrocytes showed the typical flat polygonal morphology in culture and expressed strong GFAP and vimentin. Co-cultured hippocampal neurons on astrocytes had phase bright cell body and well branched neurites. About half of co-cultured astrocytes expressed negative or weak GFAP and vimentin. After 2 hour glutamate (0.5 mM) exposure of glial-neuronal co-culture, neuronal cells lost their neurites and most of astrocytes expressed strong CFAE and vimentin. In Western blot analysis, total GFAP and vimentin contents in co-cultured astrocytes were lower than those of primary cultured astrocytes. After glutamate exposure of glial-neuronal co-culture, GFAP and vimentin contents in astrocytes were increased to the level of primary cultured astrocytes. These results suggest that neuronal cell decrease GFAP expression in co-cultured astrocytes and hippocampal neuronal-glial co-culture can be used as a reactive gliosis model in vitro for studying GFAP expression of astrocytes.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 춘계학술대회 논문집
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• pp.3-6
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• 2009

Aluminum nitride (AIN) thin films were deposited on a polycrystalline 3C-SiC intermediate layer by a pulsed reactive magnetron sputtering system. Characteristics of the AIN/SiC heterostructures were investigated by field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The columnar structure of AIN thin films was observed by FE-SEM. The surface roughness of AlN films on the 3C-SiC buffer layer was measured using AFM. The XRD pattern of AlN films on SiC buffer layers was highly oriented at (002). Full width at half maximum (FWHM) of the rocking curve near (002) reflections was $1.3^{\circ}$. The infrared absorbance spectrum indicated that the residual stress of AIN thin films grown on SiC buffer layers was nearly negligible. The 3C-SiC intermediate layers are promising for the realization of nitride based electronic and mechanical devices.

• 대한지역사회영양학회지
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• 제15권6호
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• pp.796-805
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• 2010

This study investigated the correlations and risk distribution differences between high sensitivity C-reactive protein (hs-CRP) and the diagnosis factors of metabolic syndrome among the residents of a rural community. Two thousand adults aged from 40 to 70 were recruited and 1,968 subjects were included in the study after excluding those with infectious disease or with hs-CRP higher than 10 mg/L in blood. The subjects were then divided into three groups of hs-CRP to examine the correlations and risk ratio with the risk factors of metabolic syndrome. There was a tendency of hs-CRP increasing according to the number of risk factors of metabolic syndrome. The risk ratio with hs-CRP according to metabolic syndrome significantly increased by 2.0 and 2.2 times in the intermediate and high risk group, respectively, compared with the low risk group. The risk ratio with the risk factors of metabolic syndrome according to hs-CRP rose in abdominal obesity, triglyceride, and W/Ht in the intermediate risk group of hs-CRP. The risk ratio also surged in high pressure, W/Ht, ex-drinking (1.7 times), exsmoking (2.0 times) and current smoking (2.0 times) in the high risk group. The results indicate that hs-CRP is related to the risk factors of metabolic syndrome and that it's very important to manage obesity including abdominal obesity and W/Ht and everyday habits including drinking and smoking.

• 지역사회간호학회지
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• 제20권2호
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• pp.143-151
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• 2009

Purpose: This study was to investigate the relations and odds ratio between hs-CRP and the risk factors of metabolic syndrome according to glucose intolerance and diabetes among the residents of a rural community. Methods: The subjects include 1,968 adults aged from 40 to 70 who were divided into four groups and a diabetes group according to glucose intolerance to compare the relations and risk ratio between hs-CRP and the risk factors of metabolic syndrome. Results: The results reveal that the greater the subjects' glucose intolerance was, the higher their hs-CRP became and the more risk factors of metabolic syndrome they had. The impaired glucose tolerance group showed 1.7 times higher blood pressure than the control group. The diabetes group showed a high odds ratio with 2.3 times higher blood pressure, 2.2 times higher abdominal obesity, and 2.4 times higherW/Ht than the control group. And the odds ratio increased significantly by 1.7 times in the hs-CRP intermediate risk group and 2.5 times in the high risk group compared with the control group. Conclusion: Considering the study results, it is very important to monitor abdominal obesity, blood pressure and the intermediate and high risk group of hs-CRP in order to reduce the contraction of cardiovascular diseases.