• Journal of the Korean Wood Science and Technology
• /
• v.42 no.5
• /
• pp.523-532
• /
• 2014

This study was done to evaluate the antioxidant effect of oak hot water extracts on the oxidative stress induced by reactive oxygen species (ROS). The cytotoxicity of $H_2O_2$-induced oxidative stress was performed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay for the cell viability according to the dose-dependent treatment. Oak extracts demonstrated a dose-dependent ability to inhibit $H_2O_2$-induced apoptosis in cultured tenofibroblasts, as assessed by MTT assay and FACS analysis. $H_2O_2$ increased the phosphorylation of extracellular regulated kinase1/2 (ERK1/2) and of c-Jun N-terminal kinase (JNK) and the production of reactive oxygen species (ROS). In contrast, treatment with oak extracts was decreased this activation of ERK1/2 and JNK, as confirmed by western blot analysis, and reduced the production of ROS, as verified by fluorescent microscopic and flow cytometry (FACS) analyses. These findings suggest that oak extracts, by suppressing JNK, ERK1/2, and intracellular ROS production, have a concentration-dependent antiapoptotic effect on achilles tenofibroblasts exposed to an oxidative stressor, and may have therapeutic potential.

• Journal of Hydrogen and New Energy
• /
• v.24 no.5
• /
• pp.451-460
• /
• 2013

In a direct coal fuel cell (DCFC) system, it is essential to identify volume fraction of coal suspended in electrolyte melt in order to control its dispersion and fluidity. This requirement is compelling especially at anode channel where hot slurry is likely to flow at low velocity. In this study, light scattering techniques were employed to measure the volume fraction for a pulverized coal suspension with relatively high absorption coefficient. The particle size, scattering angle, and volume fraction were varied to evaluate their effects on the scattering behavior as well as scattering regime. The larger coal size and smaller forward scattering angle could provide a shift to more favorable scattering regime, i.e., independent scattering, where interferences of light scattering from one particle with others are suppressed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.25 no.6
• /
• pp.409-413
• /
• 2012

In this study, a substrate-bias assisted 2-step pulse programming method is proposed for realizing 4-bit/1-cell operation of the SONOS memory. The programming voltage and time are considerably reduced by this programming method than a gate-bias assisted 2-step pulse programming method and CHEI method. It is confirmed that the difference of 4-states in the threshold voltage is maintained to more than 0.5 V at least for 10-year for the multi-level characteristics.

• Preventive Nutrition and Food Science
• /
• v.15 no.2
• /
• pp.92-97
• /
• 2010

Luteolin and chicoric acid are the most abundant phytochemicals in dandelion (Taraxacum officinale) leaf. In this study, four kinds of extraction methods [hot water, ambient temperature (AT) water, ethanol, and methanol] were applied to analyze the contents of both phytochemicals and verify their anti-inflammatory and antioxidative activities. The methanol extract showed the most potent nitric oxide (NO) inhibitory effect. The luteolin and chicoric acid concentrations were 3.42 and $12.86\;{\mu}g/g$ dandelion leaf in the methanol extract. The NO-suppressive effect of luteolin and chicoric acid was identified in a dose-dependent manner with $IC_{50}$ values of $21.2\;{\mu}M$ and $283.6\;{\mu}M$, respectively, in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells without cytotoxicity. Malondialdehyde (MDA) concentration, as an index for free radical injury on cell membrane, was also dose-dependently inhibited by the two compounds. The suppressive effect was further examined using mRNA and protein expression levels, which were attributable to the inhibition of inducible nitric oxide synthase (iNOS). These results suggest that two phytochemicals in dandelion leaf, luteolin and chicoric acid, may play an important role in the amelioration of LPS-induced oxidative stress and inflammation.

• Korean Journal of Medicinal Crop Science
• /
• v.21 no.1
• /
• pp.54-60
• /
• 2013

According to previous reports, antioxidant activities of Codonopsis lanceolata could be increased by a steaming process. This study was performed to improve its antioxidant activity and skin whitening activities of C. lanceolata by high pressure and stepwise steaming complex process. The complex processed C. lanceolata showed highest free radical scavenging acitivity as 45.21%, and for phenol and flavonoid contents, complex processed C. lanceolata contained higher than those from conventional extraction process or steaming process alone. The Cytotoxicity of all C. lanceolata extracts also showed low cytotoxicity against human fibroblast cell (CCD-986sk) as 4.49 ~ 10.40%. In whitening activity, high inhibition of tyrosinase activity was estimated as 25.08% by adding the extracts from complex process. We found that whitening and antioxidant activity of complex processed C. lancolata extract was higher than those obtained from conventional extraction and a steaming process because various kinds of antioxidant compounds could be easily released by combined process, compared to one of each process.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.25 no.3
• /
• pp.470-477
• /
• 1996

This study was intended to observe the changes of pectic substances and enzyme activities, texture, microstructure of anchovy added kimchi during fermentation for 4 weeks at 4$^{\circ}C$. Content of alcohol insoluble solid(AIS) and HCl soluble pectin(HClSP) were decreased, whereas content of hot water soluble pectin(HWSP) was increased during fermentation. Content of HClSP was higher and HWSP was lower in anchovy added kimchi than control. Activity of pectinesterase(PE) was decreased, whereas activity of polygalacturonase(PG) was increased during fermentation. In anchovy added kimchi, PG activity was lower than control. Changes in microstructure of Chinese cabbage and kimchi during fermentation was lower than control. Changes in microstructure of Chinese cabbage and kimchi during fermentation was observed ; in the raw cabbage, parenchyma cells, intercellular space and middle lamella were clearly shown. But in salted cabbage, middle lamella became separated. In the late stage of fermentation, parenchyma cell walls were wrinkled and collapsed. Puncture forces of kimchi were decreased, whereas cutting forces of kimchi were increased as fermentation proceeded. The firmness was slightly higher in anchovy added kimchi than control at the late stage fermentation, which may be explained by the PG activity.

• Biomolecules & Therapeutics
• /
• v.8 no.2
• /
• pp.199-205
• /
• 2000

On the inter-order protoplast fusants of Lentinus edodes and Ganoderma lucidum was the antitumor activity test performed and the fusant P22 was selected. The hot water extract of the cultured mycelia of P22 were purified by DEAE-cellulose chromatographya and the resulting purified fraction was designated as P22A. It was found to be a proteoglycan whose molecular weight was 47 kDa. When examined for immunopotentiation activity, P22A increased the number of colony forming unit in the bone marrow stem cells to 3-folds. It also potentiated the secretion of nitric oxide in activated macrophages to 2-folds. In humoral immune response, it increased the activities of the alkaline phosphatase in differentiated B cells to 1.6-folds and the number of plaque forming cells to 1.8-folds. In cellular immune response, it restored the depressed response of delayed type hypersensitivity in tumor bearing mice to normal level. These results suggest that P22A have potential to restore the decreased immune activity of the tumor bearing mice to normal level.

• Journal of the Korean Wood Science and Technology
• /
• v.26 no.1
• /
• pp.29-37
• /
• 1998

Alkali-soluble extracts were prepared from medium-sized barks of Radiata pine(Pinus radiata). There are difficulties in the production of extracts with uniform quality and in the preparation of adhesives with suitable viscosity. Ultrafiltration using an Amicon cell was subjected to fractionate extracts according to molecular sizes in order to overcome the above problem. The filtration efficiency was studied by using thin channel filtration systems. Adhesive manufacturing was also examined. Removal of particles greater than 0.45m from the extracts increased both filtration speed (flux) and yields of solids in the filtrates. Ultrafiltration with PM 10 membrane was very effective to fractionate and concentrate the extracts. Stiasny precipitates from the filtrates obtained by PM 10 membrane were very lower than that(83%) of the retentates. This ultrafiltration method was efficient for obtaining high yield purified phenolic compounds(mainly polyflavanoids) and thus important for preparing wood adhesives from barks. The extracts were shown excessive high viscosities at the concentrations required for adhesive formulation, but this high viscosity and short gelation time was reduced by lowering pH of the extracts and addition of urea. The highest bonding strength of plywoods(340g/$m^2$ of adhesive spreads) was achieved with adhesive formulated by 100parts of mixed alkali extracts and urea(70/30,w/w), 10parts of p-formaldehyde and 3.5parts of wheat flour at pH 6, and by hot pressing at the conditions of 12kg/$cm^2$ at $120^{\circ}C$ for 10 minutes.

• 한국신재생에너지학회:학술대회논문집
• /
• 2009.11a
• /
• pp.396-396
• /
• 2009

Chalcopyrite semiconductor $CuInSe_2$ nanoparticles were prepared using a low temperature colloidal route by reacting the starting materials (CuI, $InI_3$ and $Na_2Se$) in solvents. After synthesised $CuInSe_2$ nanoparticles precursors were mixed with organic binder for the viscosity of the precursor slurry to be suitable for the doctor blade method. The mixture of $CuInSe_2$ and binder was deposited onto molybdenum-coated sodalime glass substrates to form thin film. The precursor thin films were preheated on the hot plate to remove remaining solvents and binder material. After subsequent thermal processing of the thin film under a selenium ambient, $CuInSe_2$ absorber layer with grain size significantly lager than that of the nanoparticles was formed.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.2 no.3
• /
• pp.155-164
• /
• 2004

Advanced spent fuel Conditioning Process(ACP) project which is under development for efficient spent fuel management has finished process feasibility study and is preparing $\alpha$-${\gamma}$ type hot cell construction for process experimentation. Radiation dose evaluation for the radioactive nuclides were preliminarily performed for normal operation and accident case with the basic concept design report, the meteorological data and the recent site specific data. According to the production and release rate of nuclides, dose evaluations for residents around facility were performed. The evaluation result shows a safe margin for regulation limits and SAR(Safety Analysis Report) limit of IMEF(Irradiated Material Examination Facility) where this facility will be constructed.