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Tenan, South Korea

Lee J.H.,KEPCO E&C | Shim S.-B.,Bugil Academy
Korean Chemical Engineering Research | Year: 2014

Regarding the design of the gas sweetening absorber, the gas distribution analysis for the increase of the sour gas removal and reduction of the tower height is very important research topics. Recently, regarding the CO2 capture technology which is a promising option for the reduction of the greenhouse gas (GHG), the need for the gas distribution improvement is increased as the gas treating capacity increases. In this paper, we have investigated the sour gas distribution in the absorber using CFD (Computational Fluid Dynamics) based on 10 MW post-combustion CO2 capture plant installed in Boryeong power station, Korea Midland Power company. For this purpose, we suggested the three possible technology options (splash plate, spiral gas line and U-tube) for the gas distribution enhancement and compared the effect of the each cases. The result showed that the U-tube installed in the absorber increase the gas distribution about 30% compared to the base case, while the delta P increasement was about 10%. From these results, it was found that the U-tube installation is an effective technology option for the gas distribution enhancement in the gas sweetening absorber. Source


Lee C.-G.,Gwangju Institute of Science and Technology | Kwon H.-K.,Gwangju Institute of Science and Technology | Ryu J.H.,Gwangju Institute of Science and Technology | Kang S.J.,Gwangju Institute of Science and Technology | And 3 more authors.
BMC Complementary and Alternative Medicine | Year: 2010

Background: Abalone has long been used as a valuable food source in East Asian countries. Although the nutritional importance of abalone has been reported through in vitro and in vivo studies, there is little evidence about the potential anti-tumor effects of abalone visceral extract. The aim of the present study is to examine anti-tumor efficacy of abalone visceral extract and to elucidate its working mechanism.Methods: In the present study, we used breast cancer model using BALB/c mouse-derived 4T1 mammary carcinoma and investigated the effect of abalone visceral extract on tumor development. Inhibitory effect against tumor metastasis was assessed by histopathology of lungs. Cox-2 productions by primary and secondary tumor were measured by real-time RT-PCR and immunoblotting (IB). Proliferation assay based on [3H]-thymidine incorporation and measurement of cytokines and effector molecules by RT-PCR were used to confirm tumor suppression efficacy of abalone visceral extract by modulating cytolytic CD8+ T cells. The cytotoxicity of CD8+T cell was compared by JAM test.Results: Oral administration of abalone visceral extract reduced tumor growth (tumor volume and weight) and showed reduced metastasis as confirmed by decreased level of splenomegaly (spleen size and weight) and histological analysis of the lung metastasis (gross analysis and histological staining). Reduced expression of Cox-2 (mRNA and protein) from primary tumor and metastasized lung was also detected. In addition, treatment of abalone visceral extract increased anti-tumor activities of CD8+T cells by increasing the proliferation capacity and their cytolytic activity.Conclusions: Our results suggest that abalone visceral extract has anti-tumor effects by suppressing tumor growth and lung metastasis through decreasing Cox-2 expression level as well as promoting proliferation and cytolytic function of CD8+T cells. © 2010 Lee et al; licensee BioMed Central Ltd. Source


Kwon H.-K.,Gwangju Institute of Science and Technology | Hwang J.-S.,Gwangju Institute of Science and Technology | So J.-S.,Gwangju Institute of Science and Technology | Lee C.-G.,Gwangju Institute of Science and Technology | And 8 more authors.
BMC Cancer | Year: 2010

Background: Cinnamomum cassia bark is the outer skin of an evergreen tall tree belonging to the family Lauraceae containing several active components such as essential oils (cinnamic aldehyde and cinnamyl aldehyde), tannin, mucus and carbohydrate. They have various biological functions including anti-oxidant, anti-microbial, anti-inflammation, anti-diabetic and anti-tumor activity. Previously, we have reported that anti-cancer effect of cinnamon extracts is associated with modulation of angiogenesis and effector function of CD8+T cells. In this study, we further identified that anti-tumor effect of cinnamon extracts is also link with enhanced pro-apoptotic activity by inhibiting the activities NFκB and AP1 in mouse melanoma model.Methods: Water soluble cinnamon extract was obtained and quality of cinnamon extract was evaluated by HPLC (High Performance Liquid Chromatography) analysis. In this study, we tested anti-tumor activity and elucidated action mechanism of cinnamon extract using various types of tumor cell lines including lymphoma, melanoma, cervix cancer and colorectal cancer in vitro and in vivo mouse melanoma model.Results: Cinnamon extract strongly inhibited tumor cell proliferation in vitro and induced active cell death of tumor cells by up-regulating pro-apoptotic molecules while inhibiting NFκB and AP1 activity and their target genes such as Bcl-2, BcL-xL and survivin. Oral administration of cinnamon extract in melanoma transplantation model significantly inhibited tumor growth with the same mechanism of action observed in vitro.Conclusion: Our study suggests that anti-tumor effect of cinnamon extracts is directly linked with enhanced pro-apoptotic activity and inhibition of NFκB and AP1 activities and their target genes in vitro and in vivo mouse melanoma model. Hence, further elucidation of active components of cinnamon extract could lead to development of potent anti-tumor agent or complementary and alternative medicine for the treatment of diverse cancers. © 2010 Kwon et al; licensee BioMed Central Ltd. Source


Cho K.S.,Konkuk University | Joo S.H.,Konkuk University | Choi C.S.,Konkuk University | Kim K.C.,Konkuk University | And 11 more authors.
Life Sciences | Year: 2013

Aims Tissue plasminogen activator (tPA) is an essential neuromodulator whose involvement in multiple functions such as synaptic plasticity, cytokine-like immune function and regulation of cell survival mandates rapid and tight tPA regulation in the brain. We investigated the possibility that a transient metabolic challenge induced by glucose deprivation may affect tPA activity in rat primary astrocytes, the main cell type responsible for metabolic regulation in the CNS. Main methods Rat primary astrocytes were incubated in serum-free DMEM without glucose. Casein zymography was used to determine tPA activity, and tPA mRNA was measured by RT-PCR. The signaling pathways regulating tPA activity were identified by Western blotting. Key findings Glucose deprivation rapidly down-regulated the activity of tPA without affecting its mRNA level in rat primary astrocytes; this effect was mimicked by translational inhibitors. The down-regulation of tPA was accompanied by increased tPA degradation, which may be modulated by a proteasome-dependent degradation pathway. Glucose deprivation induced activation of PI3K-Akt-GSK3β, p38 and AMPK, and inhibition of these pathways using LY294002, SB203580 and compound C significantly inhibited glucose deprivation-induced tPA down-regulation, demonstrating the essential role of these pathways in tPA regulation in glucose-deprived astrocytes. Significance Rapid and reversible regulation of tPA activity in rat primary astrocytes during metabolic crisis may minimize energy-requiring neurologic processes in stressed situations. This effect may thereby increase the opportunity to invest cellular resources in cell survival and may allow rapid re-establishment of normal cellular function after the crisis. © 2013 Elsevier Inc. All rights reserved. Source


Cho S.-Y.,Kongju National University | Lee K.-W.,Kongju National University | Kim J.-W.,Bugil Academy | Kim D.-H.,Bugil Academy
Sensors and Actuators, B: Chemical | Year: 2013

Rugate-structured free-standing porous silicon was used as a membrane for a fiber-optic sensor. This material was suitable as a pressure sensitive membrane because it showed a strong peak in the reflectance spectrum which can be used for sensor signal processing and because its elasticity modulus could be easily controlled. The membranes showed an effective response in a low pressure range between 0.0 and -20.0 kPa. In addition, the membranes showed multiple responses to organic gases as well as different pressures due to their gas-sensing capability imparted by their highly porous structure. © 2013 Elsevier B.V. Source

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