• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2003.11a
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• pp.51-55
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• 2003

The thermal behavior of NiFe$_2$O$_4$ prepared by a solid-state reaction was investigated for H$_2$ generation by the thermochemical cycle. The reduction of NiFe$_2$O$_4$ started from 800 $^{\circ}C$, and the weight loss was 0.2-0.3 wt％ up to 1000 $^{\circ}C$. At this reaction, NiFe$_2$O$_4$ was reduced by release of oxygen bonded with the Fe$^3$ion in the B site of NiFe$_2$O$_4$. In the $H_2O$ decomposition reaction, H$_2$ was generated by oxidation of reduced NiFe$_2$O$_4$. The crystal structure of NiFe$_2$O$_4$ for redox reaction maintained spinel structure. Then, NiFe$_2$O$_4$ is excellent material in the thermochemical cyclic reaction due to release oxygen at low temperature for the reduction reaction and produce H$_2$ maintaining crystal structure for redox reaction.

• Journal of Life Science
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• v.20 no.7
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• pp.1121-1126
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• 2010

The oxidative stress induced by reactive oxygen species (ROS) may play an important role in the pathogenesis of neurodegenerative diseases. In this study, we investigated the neuroprotective effects of methanolic extracts of Prunella Spica (PSE) against $H_2O_2$-induced oxidative stress in PC12 cells. The cells exposed to $H_2O_2$-induced oxidative stress were treated with various concentrations of PSE; this treatment resulted in the induction of a dose-dependent protective effect, which was evidenced by the results of MTT reduction assay, lactate dehydrogenase (LDH) release assay, morphological assay, and colony-formation assay. Interestingly, we also observed reduction of apoptotic bodies in the Hoechst staining and flow cytometric analysis. These data show that apoptosis was significantly suppressed in the PC12 cells that were exposed to $H_2O_2$-induced oxidative stress and treated with PSE. These results suggest that Prunella Spica could be a new potential protective agent against $H_2O_2$-induced oxidative stress.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.2
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• pp.101-107
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• 1984

The suitable paddy soil for application of rice straw under well to moderately well drained soil, the yield and yield components were pronounced more than poorly drained soil. Based on laboratory experiment, application of rice straw promoted the decrease of oxidation-reduction potential in well to moderately well drained soil. This results seems to be enhanced the release of some mineral nutrients such as calcium, potassium, silicon, and increases of availability of soil phosphorus. This explains reason why soil condition became more favorable for the increases of mineral nutrient in rice plant. On the contrary, poorly drained soils, became readily reduced even without application or rice straw, when soil wat submerged. Application of rice straw did not promoted the decrease of oxidation-reduction potential as much as in well drained soil. It was suggested that in this type of soil series, the release of mineral nutrients and the additional increase of available soil phosphorus did not proceed well. It was also suggested that the retardation of root development owing to accumulation of toxic substances such as organic acid, hydrogen sulfide or some other reducing substances formed by the application of rice straw in poorly drained soil series might be considered. In fact, the effect of rice straw on the yield of brown rice became lower.

• Toxicological Research
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• v.35 no.1
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• pp.45-63
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• 2019

In view of the growing industrial use of Bacterial cellulose (BC), and taking into account that it might become airborne and be inhaled after industrial processing, assessing its potential pulmonary toxic effects assumes high relevance. In this work, the murine model was used to assess the effects of exposure to respirable BC nanofibrils (nBC), obtained by disintegration of BC produced by Komagataeibacter hansenii. Murine bone marrow-derived macrophages ($BMM{\Phi}$) were treated with different doses of nBC (0.02 and 0.2 mg/mL, respectively 1 and $10{\mu}g$ of fibrils) in absence or presence of 0.2% Carboxymethyl Cellulose (nBCMC). Furthermore, mice were instilled intratracheally with nBC or nBCMC at different concentrations and at different time-points and analyzed up to 6 months after treatments. Microcrystaline $Avicel-plus^{(R)}$ CM 2159, a plant-derived cellulose, was used for comparison. Markers of cellular damage (lactate dehydrogenase release and total protein) and oxidative stress (hydrogen peroxidase, reduced glutathione, lipid peroxidation and glutathione peroxidase activity) as well presence of inflammatory cells were evaluated in brochoalveolar lavage (BAL) fluids. Histological analysis of lungs, heart and liver tissues was also performed. BAL analysis showed that exposure to nBCMC or CMC did not induce major alterations in the assessed markers of cell damage, oxidative stress or inflammatory cell numbers in BAL fluid over time, even following cumulative treatments. $Avicel-plus^{(R)}$ CM 2159 significantly increased LDH release, detected 3 months after 4 weekly administrations. However, histological results revealed a chronic inflammatory response and tissue alterations, being hypertrophy of pulmonary arteries (observed 3 months after nBCMC treatment) of particular concern. These histological alterations remained after 6 months in animals treated with nBC, possibly due to foreign body reaction and the organism's inability to remove the fibers. Overall, despite being a safe and biocompatible biomaterial, BC-derived nanofibrils inhalation may lead to lung pathology and pose significant health risks.

• Journal of Nutrition and Health
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• v.56 no.2
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• pp.140-154
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• 2023

Purpose: Deodeok (Codonopsis lanceolata) is generally used in conventional medicines and is considered to have remedial properties to cure several diseases. However, application of the C. lanceolata bud as a novel food ingredient has not been fully explored. Hydrogen peroxide (H₂O₂) is associated with the production of oxidative damage that results in mutagenesis, carcinogenesis, and cell death. This study examines the neuroprotective effect of C. lanceolate bud extracts (CLBE) on H₂O₂-stimulated apoptosis in SH-SY5Y cells. Methods: C. lanceolata bud of length 10 to 15 cm was collected and extracted using 70% ethanol. Cytotoxicity was evaluated by the EZ-cytox reagent, measurement of lactic dehydrogenase (LDH) release and reactive oxygen species (ROS). The morphological changes of the nuclei were determined using the Hoechst 33258 dye. Enzyme activities were analyzed using the caspase activity assay kit. Related protein expressions were quantified by the Western blot immunoassay in H₂O₂-stimulated SH-SY5Y cells. Results: Cell viability, LDH release and ROS generation, demonstrated neuroprotective effects of CLBE in H₂O₂-stimulated SH-SY5Y cells. The occurrence of apoptosis in H₂O₂-stimulated cells was confirmed by caspase activity, which was increased in H₂O₂-stimulated SH-SY5Y cells compared to the unexposed group. Pretreatment of CLBE was observed to inhibit the H₂O₂-stimulated apoptosis. In addition, exposure to CLBE resulted in increased expression of the Bcl-2 (B cell lymphoma 2) protein and decreased expression of the Bax (Bcl2 associated X) protein. Conclusion: This study shows that exposure to CLBE alleviates the H₂O₂-stimulated neuronal damage in SH-SY5Y cells. Our results indicate the potential application of CLBE in neurodegenerative disease therapy or prevention.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.172-172
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• 2011

Anaerobic digestion(AD) has successfully been used for many applications that have conclusively demonstrated its ability to recycle biogenic wastes. AD has been successfully applied in industrial waste water treatment, stabilsation of sewage sludge, landfill management and recycling of biowaste and agricultural wastes as manure, energy crops. During AD, i.e. organic materials are decomposed by anaerobic forming bacteria and fina1ly converted to excellent fertilizer and biogas which is primarily composed of methane(CH4) and carbon dioxide(CO2) with smaller amounts of hydrogen sulfide(H2S) and ammonia(NH3), trace gases such as hydrogen(H2), nitrogen(N2), carbon monoxide(CO), oxygen(O2) and contain dust particles and siloxanes. The production and utilisation of biogas has several environmental advantages such as i)a renewable energy source, ii)reduction the release of methane to the atomsphere, iii)use as a substitute for fossil fuels. In utilisation of biogas, most of biogas produced from small scale plant e.g. farm-scale AD plant are used to provide as energy source for cooking and lighting, in most of the industrialised countries for energy recovery, environmental and safety reasons are used in combined heat and power(CHP) engines or as a supplement to natural. In particular, biogas to use as vehicle fuel or for grid injection there different biogas treatment steps are necessary, it is important to have a high energy content in biogas with biogas purification and upgrading. The energy content of biogas is in direct proportion to the methane content and by removing trace gases and carbon dioxide in the purification and upgrading process the energy content of biogas in increased. The process of purification and upgrading biogas generates new possibilities for its use since it can then replace natural gas, which is used extensively in many countries, However, those technologies add to the costs of biogas production. It is important to have an optimized purification and upgrading process in terms of low energy consumption and high efficiency giving high methane content in the upgraded gas. A number of technologies for purification and upgrading of biogas have been developed to use as a vehicle fuel or grid injection during the passed twenty years, and several technologies exist today and they are continually being improved. The biomethane which is produced from the purification and the upgrading process of biogas has gained increased attention due to rising oil and natural gas prices and increasing targets for renewable fuel quotes in many countries. New plants are continually being built and the number of biomethane plants was around 100 in 2009.

• Journal of Pharmaceutical Investigation
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• v.29 no.1
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• pp.29-36
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• 1999

Aceclofenac is an non-steroidal antiinflammatory drug which has been used in the treatment of rheumatoidal rthritis and osteo-arthritis. In order to decrease the gastric ulcerogenic effects and contol the plasma level of aceclofenac, we have developed the transdermal delivery system of aceclofenac plaster, which were formulated employing matrix polymers of acrylates and penetration-enhancers such as $Lauroglycol^{\circledR}$, $Transcutol^{\circledR}$, oleic acid and linoleic acid. Using Franz diffusion cells mounted with a rat skin, transdermal penetration characteristics of the formulations were evaluated by the HPLC assay of aceclofenac and diclofenac, an active metabolite, in the receptor compartment of pH 7.2 phosphate buffered solution. Skin penetration was increased when the content of aceclofenac increased, showing the flux $(J,\;{\mu}g/cm^2/hr)$ of 0.37 and 2.50 for 2% and 6.75% of the content, respectively. The flux$(J,\;{\mu}g/cm^2/hr)$ from plasters made of $Durotak^{\circledR}$ 87-2074, $Durotak^{\circledR}$ 87-2510 and $Durotak^{\circledR}$ 87-2097 were 2.50, 2.77 and 4.39, respectively. $Durotak^{\circledR}$ 87-2074 showed the lowest penetration due to the carboxylic acid group in the polymer, which might form a strong hydrogen bonding with a secondary amine of aceclofenac. Although both $Durotak^{\circledR}$ 87-2510 and $Durotak^{\circledR}$ 87-2097 are amine-resistant adhesives, $Durotak^{\circledR}$ 872510 showed lower penetration than $Durotak^{\circledR}$ 87-2097 because of the hydroxyl group in $Durotak^{\circledR}$ 87-2510, which might form a weak hydrogen bonding with aceclofenac. These results reveal that the functional group in acrylic polymers would greatly affect the release of aceclofenac from the matrix, which is the rate-limiting step in the penetration of aceclofenac through rat skins. The penetration of aceclofenac from plasters using different penetration-enhancers increased in the following order: Transcutol < linoleic acid < oleic acid. And the flux from the plasters containing oleic acid as a penetrationenhancer was 2.22 times greater than that of creams, which suggest that a newly deveolped aceclofenac plaster could be used in the treatment of rheumatoidal arthritis and osteo-arthritis as an advanced transdermal delivery system.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.574-581
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• 2001

The microbial properties and acid tolerance of the three kinds of Acetobacter sp. isolated from persimmon vinegar were investigated. Acid tolerance was also evaluated. Acetobacter sp. were gram negative, short rod, nonspore forming and motile. They reacted positively catalase, methyl red, oxidation fermentation, Voges-Proskauer and nitrate reduction tests and negative to hydrogen sulfide test and ONPG. Acetobacter sp. showed normal growth curve in Carr broth and there was no significant difference between isolates and (standard on) typical strains such as Acetobacter aceti (KCTC1010), Acetobacter liquefaciens (KCTC2804), Acetobacter diazotrophicus (KCTC 2859). Optimum temperature and initial ethanol concentration in incubation were $30^{\circ}C$ and 6%, respectively. Growth and acid production of Acetobacter sp. were suppressed by the concentration of above 4% acetic acid. The amount of $Mg^{++}$ release from Acetobacter sp. cells in medium was increased by acetic acid, and almost in the concentration of 6% acetic acid. Glycolysis by Acetobacter sp. had optimal pH about 6.0 to 7.0 and more stable in acidic condition than in alkalic. The $H^+-ATPase$ of Acetobacter sp. S-1 and S-3 showed a maximal activity between pH values of approximately 5.5 to 7.5 and 6.0 to 7.5, respectively.

• Nuclear Engineering and Technology
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• v.41 no.5
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• pp.575-602
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• 2009

In the wake of the Three Mile Island accident, vigorous research efforts were initiated to acquire a basic knowledge of the progression and consequences of accidents that involve a substantial degree of core degradation and melting. The primary emphasis of this research was placed on containment integrity, with: i) hydrogen combustion-detonation, ii) steam explosion, iii) direct containment heating (DCH), and iv) melt attack on the BWR Mark-I containment shell identified as energetic processes that could lead to early containment failure (i.e., within the first 24 hours of the accident). Should the core melt fail the reactor vessel, then non-condensable gas production from Molten Core-Concrete Interaction (MCCI) was identified as a mechanism that could fail the containment by pressurization over the long term. One signification question that arose as part of this investigation was the effectiveness of water in terminating an MCCI by flooding the interacting masses from above, thereby quenching the molten core debris and rendering it permanently coolable. Successful quenching of the core melt would prevent basemat melt through, as well as continued containment pressurization by non-condensable gas production, and so the accident progression would be successfully terminated without release of radioactivity to the environment. Based on these potential merits, ex-vessel corium coolability has been the focus of extensive research over the last 20 years as a potential accident management strategy for current plants. In addition, outcomes from this research have impacted the accident management strategies for the Gen III+LWR plant designs that are currently being deployed around the world. This paper provides: i) an historical overview of corium coolability research, ii) summarizes the current status of research in this area, and iii) highlights trends in severe accident management strategies that have evolved based on the findings from this work.

• Biomolecules & Therapeutics
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• v.13 no.4
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• pp.207-213
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• 2005

It has been proposed that reactive oxygen species (ROS), mainly superoxide anion ($O_2^-$) and hydrogen peroxide ($H_2O_2$), may mediate oxidative stress. Production of $H_2O_2$ during oxidative phosphorylation, inflammation, and ischemia can cause oxidative stress leading to cell death. Although glucose oxidase (GOX) in the presence of glucose continuously generates $H_2O_2$, it is not clear whether GOX produces apoptotic cell death in C6 glial cells. Thus, we investigated the mechanism by which GOX induces cell death. Cells were incubated with different concentration of GOX in the presence of glucose where cell viability, TUNEL and DNA ladder were analyzed. Results indicated that GOX exhibited cytotoxicity in a dose dependent manner by MTT assay. TUNEL positive cell and DNA laddering showed that GOX-induced cytotoxicity was due to apoptosis. Western blot analysis also showed that the cleaved caspase-3 level was detected in the GOX-treated cells at 10 mU/ml and increased dramatically at 30 mU/ml. Cleaved PARP also appeared at 10 mU/ml and lasted at 20 or 30 mU/ml of GOX. Cytochrome c level was increased by GOX dose dependently, which was contrast to Bcl-2 expression level. These results suggest that GOX induces apoptosis through caspase-3 activation, which followed by cytochrome c release from mitochondria through regulating of Bcl-2 level.