• Journal of Chest Surgery
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• v.25 no.4
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• pp.347-355
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• 1992

The precise mechanism of the Excitation-Contraction Coupling is still uncertain. But the concept that Ca2+ induced Ca2+ release [CICR] from the Ryanodine receptor in the sarcoplasmic reticulum [foot structure] may play a major role in E-C coupling has been widely accepted since 1970`s. It is believed that increased cytosolic Ca2+ followed by CICR is main contributor for E-C coupling of striated muscle. Resulting phenomena of ischemic /post-reperfusion myocyte is increased cytosolic Ca2+, even to the absence of Ca2+ in reperfusate. So intracellular inhibitor to CICR might prevent the ischemic and reperfusion damage of myocardial cells. The relatively purified foot protein, especially heavy sarcoplasmic reticulum rich, of the skeletal muscle was incorporated into the black lipid bilayer [Phosphatidyl ethanolamine: Phosphatidyl serine=l: 1]. Under the steady state of membrane potential [+20 mV], ionic current through Ryanodine receptor was measured with Cs+ as charge carrier. In the cis chamber [Cytoplasmic side], Mg2+ strongly inhibited CICR of Ryanodine receptor[Kd=6.2 nM]. In conclusion, naturally existing intracellular free Mg2+ can inhibit CICR from intracellular Ca2+ reservior [heavy SR]. So post-ischemic or post-reperfusing myocardium could be preserved using additional free Mg2+ in cardioplegic solution or reperfusate, otherwise the optimal concentration is undetermined.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1081-1086
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• 2010

The general soil nailing support system may result in excessive deformations particularly in an excavation zone of the existing weak subsoils. Pretensioning the soil nails then, could play important roles to reduce deformations mainly in part of the nailed-soil excavation system as well as to improve local stability. Morever, soil nails are installed underneath roads, underground structures, and subway structures, thereby resulting in difficulties in nail remval after completion of temporary soil nailed walls. Hence, to date, in order to solve the technical difficulties and avoid legal issues related to the construction of soil nails underneath the surrounding areas and structures, the removable soil nailing system has been developed and used. But, Therefore, a new soil nailing technique called Removable Post-tensioned Soil Nailing(RPTN) system has been developed in the current study. In this study, an investigation of the RPTN system has been conducted by carrying out field measurement. Hence, the RPTN system can reduce ground displacement and enhance stability of the soil nailed walls.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.184-184
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• 1996

Nitric Oxide Synthase(NO synthase: EC.1.14.13.39)는 생체내에서 L-arginine을 기질로 하여 nitric oxide(NO)와 L-citrulline의 생성을 매개하는 효소로서 뇌, 간장, 신장, 체장등 대부분의 주요장기와 근육세포, 신경세포 등 거의 모든 조직에 분포하고 있다. NO synthase에 의해 생성되는 NO는 혈관이완작용, 신경전달 물질로서의 작용, 면역 담당세포에서의 세포 독작용 등 많은 생리현상에 중요한 역할을 하는 것으로 알려져 있다. 특히 체장에서는 췌외분비 기능의 항진에 있어 세포내 cGMP level의 변동이 NO와 연관된다는 사실에 주목하고 있으며 본연구실에서도 이에 관한 연구가 진행중이다. 따라서 본 연구에서는 소 췌조직의 100,000$\times$g cytosol을 효소원으로 하여 다음과 같이 NO synthase의 분리, 정제를 시행하였다. Ammonium sulfate로 30%(176g solid ammonium sulfate/$\ell$) 포화, 침전 후 2',5'-ADP agarose 및 calmodulin-agarose affinity chromatography를 연속적으로 시행하여 NO synthase를 분리하였으며 electrophoresis상에서 약 160kd의 분자량을 나타내었다.

• Natural Product Sciences
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• v.26 no.3
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• pp.244-251
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• 2020

This study investigated therapeutic candidates with anti-inflammatory potential among traditional dietary ingredients targeting inflammatory bowel disease (IBD). Both Avena sativa and traditional fermented products, such as Korean soy paste, are popular health foods. We investigated the anti-inflammatory effects of soy paste combined with A. sativa (KDA), compared with soy paste without A. sativa (KD) by evaluating the expression of pro-inflammatory cytokines in lipopolysaccharide-stimulated RAW264.7 mouse macrophages and HT-29 human colon epithelial cells. KDA significantly inhibited the production of nitric oxide (NO) and downregulated the pro-inflammatory cytokines, such as interleukin (IL)-1β, IL-6, and tumor necrosis factor-α in lipopolysaccharide (LPS)-induced RAW264.7 cells. In another in vitro experiment involving LPS-stimulated HT-29 cells, KDA suppressed the levels of IL-8, which is the chemokine elevated in IBD. In addition, KDA exhibited anti-oxidative properties, such as 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and 2,2'-azino-bis(3-ethylbenz-thiazoline-6-sulfonic acid) (ABTS) radical scavenging activity. Our findings revealed that A. sativa combined with soy paste exhibits a synergistic anti-inflammatory and anti-oxidant effect following fermentation. These results suggest that KDA may be used as a potential anti-inflammatory therapy against IBD.

• The Korean Journal of Physiology
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• v.29 no.2
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• pp.191-202
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• 1995

The purpose of this study was to compare effects of insulin and IGFs on growth, apical membrane enzyme activities and membrane transport systems of primary cultured rabbit kidney proximal tubule cells. Results were as follows: 1. Insulin and IGF-I produced significant growth stimulatory effects at $5{\times}10^{-10}M.\;IGF-II(5×10^{-10}\;M)$ did not stimulate significant cell growth. 2. Insulin stimulated the phosphorylation of a 97 KD protein. It was difficult to determine whether this band represents insulin and/or the IGF-I receptor. 3. The activities of apical membrane enzymes (alkaline phosphatase, leucine aminopeptidase, and ${\gamma}-glutamyl \;transpeptidase)$ were observed to be diminished after the cells were placed in the culture environment. 4. The uptake of ${\alpha}-MG,$ Pi and Na was significantly increased in cells incubated with insulin or IGF-I, IGF-II had no effect on the uptake of these substrates. 5. Na-pump activity, as assayed by Rb uptake, was significantly increased in cells treated with insulin or IGFs. In conclusion, insulin and IGF-I exert stimulatory effects on growth and membrane transporter(glucose, Na, Pi, and Na-pump) activities in primary cultured rabbit kidney proximal tubule cells. IGF-II had no effect on cell growth and membrane transporter(glucose, Na and Pi) activities.

• Applied Biological Chemistry
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• v.36 no.1
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• pp.1-6
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• 1993

Chitinase was induced in rice cell suspension culture with treatment of chitooligosaccharides mixture. Among eleven isozymes found in 10% polysacrylamide gel electropherogram, four isozymes were identified as induced enzymes. Acidic chitinase fraction separated in DEAE-cellulose column chromatography, includes three induced chitinase, while basic fraction contains only one induced isozyme. Treatment of chitooligosaccharides mixture enhanced the contents in both protein and chitinase activity in cell suspension culture media, but increase in chitinase activity was much higher than in protein.

• Journal of the korean Society of Automotive Engineers
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• v.6 no.3
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• pp.1-8
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• 1984

한국에 이륜차가 소개된 것은 일차 경제개발 5개년계획이 시작된 1962년부터이며 초기 기아산 업에서 차체일부를 제외한 KD부품을 일본 본전기연으로부터 수입하여 조립 생산하였으며, 1975년 6월까지 약 14년간 총 93,000대를 생산한 후 1975년 7월부터 기아기연이 별도 법인으로 설립되면서부터 본격적으로 생산이 증가하게 되었고 1979년까지 독점 공급하게 되어 당시 년산 10만대를 돌파하게 되었다. 이때부터 국내 여러 업체가 출현하여 경합시대에 들어갔다. 즉, 1979년 한국 제네랄모페드(GMK)에서 이태리 Minarelli로부터 엔진 23,700대를 도입 유럽풍의 모페드(Moped)를 조립 생산하기 시작하였으나 1983년부터는 생산이 중단되었다. 1980년대는 대 림공업과 효선기계에서 각각 이륜차를 생산하기 시작하였다. 대림공업은 일본 "호다까"로부터 설비 및 기술을 도입하였으며, 효성기계 역시 일본 "스즈끼"로부터 기술을 도입하였다. 같은 해 진주 소재 동야정기에서는 서독으로부터 Sachs 엔진 6,600대를 도입하여 모페드(Crown)를 생산 판매하였으나 1982년부터 생산을 중단하였다. 다음 해인 1981년 마신산업은 이태리 피아지 오(Piaggio)로부터 엔진을 도입하여 125cc 급스쿠터를 생산하기 시작하였다. 1980년도에는 5개 업체가 이륜차 생산에 참가하였으나 자연소멸되고 또 81년 2월 28일 자동차산업 합리화조치로 대림공업과 기아기연이 합병되어 대림자동차공업(주)가 1982년 4월 설립됨으로써 현재는 효성 기계, 마신산업과 함께 3개업체가 존재하고 있다. 1975년에는 불과 3개 모델뿐이던 것이 79년 에는 5개 모델, 지금은 30개의 모델을 3개 업체에서 생산하고 있으며 그 동안 없어진 모델이 18개기종이 된다.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.1
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• pp.165-173
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• 2014

The method of emission inspection for Heavy-duty diesel vehicles has been engine speed type Lug-down 3mode. This method could bring damage to decrepit vehicles under high speed and high load condition and it could not apply the driving pattern on the road. For these reasons, this study has started to create new emission inspection which is appropriate for Korea's road infrastructure. KD 147 would be applied to light-duty diesel vehicles from july 2010 after model operations. Therefore, this study has investigated new emission inspection system for heavy-duty diesel vehicles, except for light-duty diesel vehicles. In consideration of domestic conditions to meet the new load test method in this study, the Lug-down3 mode vehicle speed method was developed for the first time in korea.

• Microbiology and Biotechnology Letters
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• v.29 no.4
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• pp.201-205
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• 2001

A bacteria strain producing extracellular $\beta$-mannanase was isolated from soil and was identified as Aeromonas sp. A genomic DNA library constructed from Aeromonas, sp that secrets a $\beta$-mannanase was screened for mannan hydrolytic acticity. Recombinant $\beta$-mannanase activity was detercted on the basis of the clear zones around Escherichia coli colonies grown on a LB medium supplemented locust bean gum, EcoRI restriction analysis of plasmid prepared from recombinant E. coli which showed a $\beta$-mannanase activity revealed 10 kb DNA insert, The optimum pH and temperature for the activity of reconmbinant $\beta$-mannanase were 6.0 and $50^{\circ}C$ respectively and were identical to those of the native enzyme.

• Structural Engineering and Mechanics
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• v.52 no.6
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• pp.1193-1208
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• 2014

A simulation of failures on responsible elements is only one form of the extreme structural behavior analysis. By understanding the dynamic behavior in incidental situations, it is possible to make a special structural design from the point of the largest axial force, stress and redundancy. The numerical realization of one such simulation analysis was performed using FEM in this paper. The boundary parameters of transient analysis, such as overall structural damping coefficient, load accelerations, time of load fall and internal forces in the responsible structural elements, were determined on the basis of the dynamic experimental parameters. The structure eigenfrequencies were determined in modal analysis. In the study, the basic incidental models were set. The models were identified by many years of monitoring incidental situations and the most frequent human errors in work with heavy structures. The combined load models of structure are defined in the paper since the incidents simply arise as consequences of cumulative errors and failures. A feature of a combined model is that the single incident causes the next incident (consecutive timing) as well as that other simple dynamic actions are simultaneous. The structure was observed in three typical load positions taken from the crane passport (range-load). The obtained dynamic responses indicate the degree of structural sensitivity depending on the character of incident. The dynamic coefficient KD was adopted as a parameter for the evaluation of structural sensitivity.