• International Journal of Oral Biology
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• v.36 no.3
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• pp.129-134
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• 2011

Eugenol is an essential oil found in cloves and cinnamon that is used widely in perfumes. However, the significant anesthetic and sedative effects of this compound have led to its use also in dental procedures. Recently, it was reported that eugenol induces apoptosis in several cancer cell types but the mechanism underlying this effect has remained unknown. In our current study, we examined whether the cytotoxic effects of eugenol upon human melanoma G361 cells are associated with cell cycle arrest and apoptosis using a range of methods including an XTT assay, Hoechst staining, immunocyto-chemistry, western blotting and flow cytometry. Eugenol treatment was found to decrease the viability of the G361 cells in both a time- and dose-dependent manner. The induction of apoptosis in eugenol-treated G361 cells was confirmed by the appearance of nuclear condensation, the release of both cytochrome c and AIF into the cytosol, the cleavage of PARP and DFF45, and the downregulation of procaspase-3 and -9. With regard to cell cycle arrest, a time-dependent decrease in cyclin A, cyclin D3, cyclin E, cdk2, cdk4, and cdc2 expression was observed in the cells after eugenol treatment. Flow cytometry using a FACScan further demonstrated that eugenol induces a cell cycle arrest at S phase. Our results thus suggest that the inhibition of G361 cell proliferation by eugenol is the result of an apoptotic response and an S phase arrest that is linked to the decreased expression of key cell cycle-related molecules.

• Nuclear Engineering and Technology
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• v.36 no.1
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• pp.24-35
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• 2004

In order to analyze the hydrogen distribution during a severe accident in the APR1400 containment, GASFLOW II was used. For the APR1400 NPP, a hydrogen mitigation system is considered from the design stage, but a fully time-dependent, three-dimensional analysis has not been performed yet. In this study GASFLOW code II is used for the three-dimensional analysis. The first step to analysis involving hydrogen behavior in a full containment with the GASLOW code is to generate a realistic geometry model, which includes nodalization and modeling of the internal structures such as walls, ceilings and equipment. Geometry modeling of the APR1400 is conducted using GUI program by overlapping the containment cut drawings in a graphical file format on the mesh view. The total number of mesh cells generated is 49,476. And the calculated free volume of the APR1400 containment by GASFLOW is almost the same as the value from the GOTHIC modeling. A hypothetical SB-LOCA scenario beyond design base accident was selected to analyze the hydrogen behavior with the hydrogen mitigation system. The source of hydrogen and steam for the GASFLOW II analysis is obtained from a MAAP calculation. Combustion pressure and temperature load possibilities within the compartments used in the GOTHIC analysis are studied based on the Sigma-Lambda criteria. Finally the effectiveness of HMS installed in the APR1400 containment is evaluated from the point of severe accident management

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.5
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• pp.421-428
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• 2004

This study concerns the characteristics of boiling heat transfer in two-phase closed thermosyphons with various micro grooves. A study was carried out with the performance of the heat transfer of the thermosyphon having 60 internal micro grooves in which boiling and condensation occur. A plain thermosyphon having the same inner and outer diameter as the grooved thermosyphon is also tested for comparison. Distilled water, methanol, ethanol have been used as the working fluid. The heat flux and the boiling heat transfer coefficient at the evaporator zone are estimated from the experimental results. The experimental results have been assessed and compared with existing correlations. Imura's and Kusuda's correlation for boiling showed in good agreement with experimental results within ${\pm}20{\%}$ in plain thermosyphon.

• Journal of Communication Design
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• v.66
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• pp.284-296
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• 2019

Thinking mode, as the condensation of the internal spirit of a nation, has been inherited till now through abundant historical precipitation, and is also a thinking tool for people to think and solve problems. Different from traditional styles and materials, the way of thinking not only has a more essential impact on design, but also makes traditional culture more vital in design. Taking the influence of Chinese mode of thinking on design thinking as the main research object, in the first place, this paper sorts out the concepts and development of thinking mode and design thinking, and summarizes three characteristics of Chinese mode of thinking: relational, collective and perceptive. Furthermore, it puts forward the influence of thinking mode on design thinking, mainly focusing on the definition of design problems, sub-problem sequencing and solution construction. Last but not least, through a series of Chinese design cases, this paper concretely analyzes how Chinese thinking mode provides national design language for Chinese design.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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• v.6 no.1
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• pp.81-97
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• 2000

Objectives: This experimental study was carried out to evaluate the effects of aqueous and methanol extracts of Hedyotis diffusa which has long been used for cancer treatment in oriental medicines on the induction of apoptotic cell death in human lymphoid leukemia cell line, HL-60. Methods: Cells were treated with various concentrations (200 to $0.4{\mu}g$) and periods (6 to 30 hr) of $H_2O$ and methanol extracts of Hedyotis diffusa. Then, cells were tested for viability by MTT assay. Cells wrere treated with $200{\mu}g/ml$ of methanol extract fork various periods. Genomic DNA was isolated, separated, on 1.5% agarose gels, stained with ethidium bromide and visualized under UV light. Cells were treated with $200{\mu}g/ml$ of each extract for 16 hr. Then, cells were treated with Hoechst dye 33342 and observed by fluorescence microscopy. Cells were treated with various doses of each for 12 hr and $100{\mu}g/ml$ of methanol extract for various periods. Lysate from the cells used to measure the activity of Caspase-1 and-3 proteases by using fluorogenic peptide substrates including acetyl-YVAD-AMC and acetyl-DEVD-AMC, respectively. Cells were treated with $200{\mu}g/ml$ of each extract for various periods. Cell lysates were immunoprecipated with anti-JNKl antibodies. The immune complex was reacted with $32^p-ATP$ and c-Jun as a substrate. The phosphotransferase activity of JNKI was measured by using PhosphoImage analyzer (Fuji Co., Japan). Nuclear extracts were isolated and incubated with oligonucleotide probe of $NF-{\kappa}B$. Transcriptional activation of ${\kappa}B$ was measured by using EMSA and visualized by PhosphoImage analyzer (Fuji Co, Japan). Cell lysates were prepared and analyzed by Western blotting with anti-Bc12 antibodies and anti-Bax antibodies. Cells were pretreated with various doses of methanol extract for 2 hr. Then, the extract was removed by centrifugation. Cells were resuspended with RPMI-1640 media containing 0.3% agarose, 10% FBS, overlayred onto bottom layer agarose and incubated at $CO_2$ incubator for 6 days. The number of colony was counted under light microscopy ($\time100$). Results: The death of HL-60 cells was markedly induced by the addition of methanol extract of Hedyotis diffusa in a dose and time-dependent manners. The apoptotic characteristic ladder pattern of DNA strand break was observed in death of HL-60 cells. In addition, it was shown nucleus chromatin condensation and fragmentation under Hoechst staining. Therefore, Hedyotis diffusa extract-induced death of HL-60 cells is mediated by apoptotic signaling processes. The activity of Caspase 3-like proteases remained in a basal level in HL-60 cells treated with aqueous extract of Hedyotis diffusa. However, it was markedly increased in HL-60 cells treated with methanol extract of Hedyotis diffusa. In addition, the phosphotransferase activity of JNKl was increased in HL-60 cells treated with methanol extract of Hedyotis diffusa. Furthermore, the activation of transcriptional activator, $NF-{\kappa}B$ was markedly induced by methanol extract of Hedyotis diffusa. Anti-apoptotic Bc12 was cleaved into 23Kda fragment by treatment of methanol extract of Hedyotis diffusa. However, expression of proapoptotic Bax protein was increased by treatment of methanol extract of Hedyotis diffusa in a time-dependent manner. Furthermore, methanol extract markedly inhibited the colony forming efficiency of HL-60 cells in semisolid agar culture. Conclusions: Above results suggest that methanol extract of Hedyotis diffusa induces the apoptotic death of human leukemic HL-60 cells via activations of Caspase-3 proteases, JNKI, transcriptional activator $NF-{\kappa}B$, In addition, our results also suggest that methanol extract of Hedyotis diffusa reduces the malignant potential of HL-60 cells via down regulation of colony forming effciency through cleavage of Bc12 as well as induction of Bax.

• Journal of Life Science
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• v.18 no.1
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• pp.120-128
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• 2008

The death ligand tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)/ Apo1L is a cytokine that activates apoptosis through cell surface death receptors. TRAIL has sparked growing interest in oncology due to its reported ability to selectively trigger cancer cell death. Euphorbiae humifusae Wind has been used in traditional Oriental medicine as a folk remedy used for the treatment of cancer. However, the mechanism responsible for the anticancer effects of E. humifusae not clearly understood. Here, we show that treatment with subtoxic doses of water extract of E. humifusae (WEEH) in combination with TRAIL induces apoptosis in TRAIL-resistant human gastric carcinoma AGS cells. Combined treatment with WEEH and TRAIL induced chromatin condensation and sub-G1 phase DNA content. These indicators of apoptosis were correlated with the induction of caspase activity that resulted in the cleavage of poly (ADP-ribose) polymerase. Combined treatment also triggered the loss of mitochondrial membrane potential. Furthermore, co-treatment with WEEH and TRAIL down-regulated the protein levels of the anti-apoptotic proteins such as Bcl-2, Bcl-xL, XIAP and cIAP-1. Although more study will be needed to examine the detailed mechanisms, this combined treatment may offer an attractive strategy for safely treating gastric adenocarcinomas and the results provide important new insights into the possible molecular mechanisms of the anticancer activity of E. humifusae.

• Journal of Life Science
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• v.23 no.3
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• pp.389-398
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• 2013

Platycodin D is a major constituent of triterpene saponins, which is found in the root of Platycodon grandiflorum, Platycodi Radix, which is widely used in traditional Oriental medicine for the treatment of many chronic inflammatory diseases. Several pharmacological effects of this compound have been reported recently, such as anti-inflammation, immunogenicity, anti-adipogenesis, lowered cholesterol, and anti-cancer activity. However, the mechanism by which this action occurs is poorly understood. In this study, we found that platycodin D greatly increased the potential of the anti-proliferative effect in various cancer cell lines. Our data revealed that platycodin D treatment resulted in a time- and concentration-response growth inhibition of U937 cells by inducing apoptosis, as evidenced by the formation of apoptotic bodies, chromatin condensation, and the accumulation of cells in the sub-G1 phase. Apoptosis induction of U937 cells by platycodin D correlated with an increase in the Bax/Bcl-2 ratio and caused the down-regulation of IAP family members. In addition, platycodin D treatment resulted in proteolytic activation of caspase-3, the concomitant degradation of poly(ADP-ribose) polymerases, and the collapse of the mitochondria membrane potential (${\Delta}{\Psi}_m$). However, the cytotoxic effects induced by platycodin D treatment were significantly inhibited by z-DEVD-fmk, a caspase-3 inhibitor, which demonstrated the important role that caspase-3 played in the observed cytotoxic effect. These findings suggest that platycodin D may be a potential chemotherapeutic agent for use in the control of human leukemia U937 cells. These findings also provided important new insights into possible molecular mechanisms of the anti-cancer activity of platycodin D.

• Journal of the Korean Ceramic Society
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• v.41 no.10 s.269
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• pp.777-782
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• 2004

In this research, $5\times5cm^2$ unit cells were fabricated via liquid condensation process and uniaxial pressing followed by the screen printing of electrolyte and cathode layer. The SOFC stack was assembled with unit cells, gasket-type sealant and metal interconnect. The stack was designed to have a single column with internal-manifold and cross-flow type gas-channels. The SOFC stack produced 15 W, which is $50\%$ of the maximum power being expected from the maximum power density of the unit cell. Controlling factors for the proper operation of the SOFC stack and other designing factors of stack manifold and gas channels were discussed.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.1
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• pp.10-26
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• 2013

To understand the traffic emissions with high temporal and spatial resolutions on road, a mobile laboratory was developed. The objective of this study is to characterize on-road air pollution on Naebu express way surrounding the northern area of Seoul, Korea. We measured the number concentration of ultrafine particles larger than 5 nm and particle size distribution using a condensation particle counter and a fast mobility particle sizer, respectively on 3, 7, and 8 December 2009. The average ultrafine particle number concentration on the Naebu express way excluding tunnels was 126,000 particles/$cm^3$ and 4.2 times higher than that on internal road at Korea Institute of Science and Technology in Seoul, and more than twice higher than that measured on and at the arterial roads of Seoul in previous studies. The maximum ultrafine particle number concentration was observed at the tunnel sections. It was 232,000 particles/$cm^3$ and 1.8 times higher than average ultrafine particle number concentration for the other sections on Naebu express way. The ultrafine particle number concentration on the wider roads with higher traffic volume along the Han River was similar to that in the residential section, probably because of enhanced dilution effect in widely open environment. The size distribution of particles on the Naebu express way was highly fluctuated for a short duration. Ultrafine particles measured at the tunnel showed a bimodal size distribution with mode diameters of ~10 nm and ~50 nm. At the Han riverside section, ~10 nm particles appeared significantly compared with size distribution at the tunnel. This on-road measurement approach can be utilized to manage vehicle-related air pollution in urban area.

• Korean Journal of Environmental Biology
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• v.31 no.3
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• pp.204-212
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• 2013

This study analyzed the occurrence of tunic softness, survival rate, metabolic rate and histopathologic changes arising from the effect of hypoxic environment in order to find the causes of occurrences of tunic softness, which manifests as the key phenomenon of mass mortality of Halocynthia roretzi. Regarding the survival of H. roretzi with reduction in dissolved oxygen, all the entities died on the 4th day of exposure to the dissolved oxygen concentration of $2mg\;L^{-1}$ while 50% mortality was observed on the 5th day of exposure to the dissolved oxygen concentration of $3mg\;L^{-1}$. Therefore the 5 days-$LC_{50}$ was found to be $3.55mg\;L^{-1}$ (1.86~$4.96mg\;L^{-1}$). However, occurrence of tunic softness was not observed during the period of exposure to low oxygen concentration. The oxygen consumption rate significantly decreases at the dissolved oxygen concentration of less than $5mg\;L^{-1}$ in comparison to the control group. Therefore, it is presumed that H. roretzi controls the respiration rate for prescribed period of time when exposed to hypoxic environment. Regarding the histopathologic changes in the gill, digestive gland and cyst of H. roretzi due to hypoxic environment, necrosis of epithelial layer, in filtration of blood cells, and condensation of nucleus that compose each of the organs were observed. Regarding morphological changes, the decrease in volume with shrinking of the tunic, discoloration of the internal organs and necrosis of gill and hepatopancreas were observed.