• Biomolecules & Therapeutics
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• v.12 no.2
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• pp.92-100
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• 2004

Effect of the depletion or oxidation of GSH on mitomycin c (MMC)-induced mitochondrial damage and cell death was assessed in small cell lung cancer (SCLC) cells. MMC induced cell death and the decrease in the GSH contents in SCLC cells, which were inhibited by z-LEHD.fmk (a cell permeable inhibitor of caspase-9), z-DQMD.fmk (a cell permeable inhibitor of caspase-3) and thiol compound, N-acetylcysteine. MMC caused nuclear damage, release of cytochrome c and activation of caspase-3, which were reduced by N-acetylcysteine. The depletion of GSH due to L-butionine-sulfoximine enhanced the MMC-induced cell death and formation of reactive oxygen species in SCLC cells, whereas the oxidation of GSH due to diamide or $NH_2Cl$ did not affect cytotoxicity of MMC. The results show that MMC may cause cell death in SCLC cells by inducing mitochondrial dysfunction, leading to activation of caspase-9 and -3. The MMC-induced change in the mitochondrial membrane permeability, followed by cell death, in SCLC cells may be significantly enhanced by the depletion of GSH. In contrast, the oxidation of GSH may not affect cytotoxicity of MMC.

• Microbiology and Biotechnology Letters
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• v.1 no.1
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• pp.19-23
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• 1973

This experiment was done to investigate the growth and the fine structural changes of Bacillus subtilis which were influenced by the penicillin with electromicroscope. The results were as follows; 1) The higher the concentration of penicillin the more prominent inhibition of the growth was observed. 2) The septa was not formed, derangements of synthesis of cell wall and cell membrane. 3) Cytoplasm was increased with swelling of cell body because of weakness of cell membrane induced by deranged synthesis of cell membrane. Some of the cells showed disruption of their membrane with loss of cytoplasm, remaining empty space, which suggest loss of cell function. 4) It can be suggested that penicillin had affected on the cell wall of Bacillus subtilis, and inhibited growth of the cell by deranging the formation of the cell wall.

• Food Science and Biotechnology
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• v.15 no.4
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• pp.534-542
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• 2006

The effects of ethanol fractions of three different rice grain extracts, Jakwangchalbyeo, Hwasunchalbyeo, and Ilpumbyeo, on apoptotic cell death in the rat hepatoma H4IIE cell line were investigated using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] cell viability assay. One hundred mg/mL Jakwangchalbyeo extract significantly reduced cell viability to 69.5, 57.2, and 46.1% within 24, 48, and 72 hr, respectively. Fluorescence-activated cell sorting (FACS) analyses were also performed to characterize the cell death pattern caused by treatment with the rice grain extracts. Apoptotic cell death was clearly observed with time after treatment with the Jakwangchalbyeo extract. In Western blotting analysis, degradation of the 116 kDa poly-ADP-ribose polymerase (PARP) molecule was observed with concomitant formation of an 89 kDa product 24, 48, and 72 hr after treating cells with the Jakwangchalbyeo extract. This indicates that an apoptotic process caused cell death in these cells. In conclusion, red-pericarp Jakwangchalbyeo extract induced apoptotic cell death in H4IIE cells to a larger extent than the other rice extracts.

• Journal of Korean Institute of Industrial Engineers
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• v.12 no.2
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• pp.45-55
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• 1986

A method for forming production cells in cellular manufacturing systems is presented. The basic approach is based on part-machine group formation by using relationship matrix calculated from the original part-machine matrix. The cases of exceptional elements and bottleneck machines are discussed. The proposed method can work with any starting form of part-machine matrix and provides the same solution regardless of the changes of starting form of part-machine matrix for any given problem.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.127-128
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• 2006

Nafion/basic polymer composite membranes were prepared to reduce the methanol crossover for the application of direct methanol fuel cell. The thermal and mechanical properties increased with increasing basic polymer contents due to the formation of complex via acid/basic interaction. The water uptake, proton conductivity, methanol permeability decreased with increasing basic polymer concentration by reduction of acidity associated with the formation of acid/base complex. The molecular effect on those properties was not considerable.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.16 no.28
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• pp.203-209
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• 1993

In Factory Automation environments such as FMS, the formation of machine-part based on GT should be considered. The purpose of this study is to develop a economic heuristic algorithm which considers various elements such as unit processing time, subcontract cost, and functional operation cost, machine processing capacity etc. When this proposed approach is applied to the real situation expected benefits are as follows: the reduction of production lead time work in process, labor force, tooling, rework and scrap, setup time, order time delivery, and paper work, etc.

• YAKHAK HOEJI
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• v.39 no.5
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• pp.560-564
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• 1995

Thirty ellagitannins originated from some Euphorbiaceous plants were tested for the inhibitory activities against AMV reverse transcriptase and replication of HIV-1 using syncytia forming assay. Most of ellagitannins showed strong inhibitory activities against AMV reverse transcriptase. Some ellagitannins including geraniin, mallotusinin, elaeocarpusin, euphorscopin and jolkianin, showed significant inhibitory activities of syncytia formation of supT1 cell line.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.1
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• pp.41-48
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• 1998

The present study was undertaken to characterize homocysteic acid (HCA)-and cysteic acid (CA)-mediated formation of inositol phosphates (InsP) in primary culture of rat cerebellar granule cells. HCA and CA stimulated InsP formation in a dose-dependent manner, which was prevented by the N-methyl-D-aspartate (NMDA) receptor antagonist D,L-2-amino-5-phosphopentanoic acid (APV). CA-, but not HCA-, mediated InsP formation was in part prevented by the metabotropic glutamate receptor antagonist ?${\alpha}$-methyl-4-carboxyphenylglycine ($({\pm})$-MCPG). Both HCA- and CA-mediated increases in intracellular calcium concentration were completely blocked by APV, but were not altered by $({\pm})$-MCPG. CA-mediated InsP formation was in part prevented by removal of endogenous glutamate. In contrast, the glutamate transport blocker L-aspartic acid-${\beta}$-hydroxamate synergistically increased CA responses. These data indicate that in cerebellar granule cells HCA mediates InsP formation wholly by activating NMDA receptor. In contrast, CA stimulates InsP formation by activating both NMDA receptor and metabotropic glutamate receptor, and in part by releasing endogenous glutamate into extracellular milieu.

• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.975-982
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• 2008

We investigated whether transplantation of osteogenically differentiated bone marrow-derived mesenchymal stem cells (BMMSCs) and the use of an hydroxyapatite (HAp) scaffold can enhance the in vivo bone formation efficacy of human BMMSCs. Three months after implantation to the subcutaneous dorsum of athymic mice, transplantation of osteogenically differentiated human BMMSCs increased the bone formation area and calcium deposition to 7.1- and 6.2-folds, respectively, of those of transplantation of undifferentiated BMMSCs. The use of the HAp scaffold increased the bone formation area and calcium deposition to 3.7- and 3.5-folds, respectively, of those of a polymer scaffold. Moreover, a combination of transplantation of osteogenically differentiated BMMSCs and HAp scaffold further increased the bone formation area and calcium deposition to 10.6- and 9.3-folds, respectively, of those of transplantation of undifferentiated BMMSCs seeded onto polymer scaffolds. The factorial experimental analysis showed that osteogenic differentiation of BMMSCs prior to transplantation has a stronger positive effect than the HAp scaffold on in vivo bone formation.

• The Journal of the Acoustical Society of Korea
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• v.36 no.3
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• pp.172-178
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• 2017

Ultrasound has been widely used for biological and medical applications including induction of cell death, but a precise mechanism of induced cell death by ultrasound is controversial. In this study, an irradiation system with 40 kHz ultrasound was developed for a suitable cell death test of a representative unicellular organism, yeast, and used to study the biological effect of ultrasound on inducing cell death. Potassium Iodide (KI) dosimetry was used to devise an optimal system that successfully delivers 40 kHz ultrasound and produces reactive oxygen species in a 1.5 ml Eppendorf tube. Cell death was observed in an ultrasound transmission time-dependent fashion in this system. Thermal effect during irradiation was not observable in ultrasound induced cell death. Co-treatment of 40 kHz ultrasound and hydrogen peroxide showed a synergistic effect in inducing cell death. This finding suggests that 40 kHz ultrasound is related to reactive oxygen species formation. However, NAC (N-acetyl-L-cysteine) oxygen scavenger slightly inhibited the cell death by 40 kHz ultrasound. It was also found that 40 kHz ultrasound induced cell death was slightly inhibited by inhibitors of necrosis or apoptosis (glycyrrhizin or zVAD-fmk). This study suggests that cell death induced by 40 kHz ultrasound may not be exclusively related to reactive oxygen species formation and thermal effects in irradiated yeast cells.