• Microbiology and Biotechnology Letters
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• v.35 no.4
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• pp.292-297
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• 2007

The unicellular green alga, Haematococcus pluvialis used as a biological production system for astaxanthin. It accumulates large amounts of the red ketocarotenoid astaxanthin when exposed to various environmental stress such as active oxygen species and high light intensities. To induce astaxanthin biosynthesis of H. pluvialis, cells were incubated in either nitrate free at $25^{\circ}C$ under continuous high light intensity ($1,000\;{\mu}mol$ photons $m^{-2}s^{-1}$) for 2 days or high light stress only. Expressions of astaxanthin biosynthetic genes such as carotenoid hydroxylase, IPP isomerase and ${\beta}$-carotene ketolase were monitored under different culture conditions by using real time RT-PCR. All the subjected genes increased their expression under highlight and N-deprivation condition where a large amount of astaxanthin was accumulated.

• Journal of Ginseng Research
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• v.42 no.2
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• pp.175-182
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• 2018

Background: The impact of fungicide azoxystrobin, applied as foliar spray, on the physiological and biochemical indices and ginsenoside contents of ginseng was studied in ginseng (Panax ginseng Mey. cv. "Ermaya") under natural environmental conditions. Different concentrations of 25% azoxystrobin SC (150 g a.i./ha and 225 g a.i./ha) on ginseng plants were sprayed three times, and the changes in physiological and biochemical indices and ginsenoside contents of ginseng leaves were tested. Methods: Physiological and biochemical indices were measured using a spectrophotometer (Shimadzu UV-2450). Every index was determined three times per replication. Extracts of ginsenosides were analyzed by HPLC (Shimadzu LC20-AB) utilizing a GL-Wondasil $C_{18}$ column. Results: Chlorophyll and soluble protein contents were significantly (p = 0.05) increased compared with the control by the application of azoxystrobin. Additionally, activities of superoxide dismutase, catalase, ascorbate peroxidase, peroxidase, and ginsenoside contents in azoxystrobin-treated plants were improved, and malondialdehyde content and $O_2^-$ contents were reduced effectively. Azoxystrobin treatments to ginseng plants at all growth stages suggested that the azoxystrobin-induced delay of senescence was due to an enhanced antioxidant enzyme activity protecting the plants from harmful active oxygen species. When the dose of azoxystrobin was 225 g a.i./ha, the effect was more significant. Conclusion: This work suggested that azoxystrobin played a role in delaying senescence by changing physiological and biochemical indices and improving ginsenoside contents in ginseng leaves.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05c
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• pp.231-237
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• 1996

Defect equilibrium equations were modelled, and the relations of P $o_2$, venus x were derived using the mass action law. The dominant defect species active in a specified region were determined by fitting the curve of experimental data to the calculated curve of log P $o_2$, versus log x for each theoretical model. The calculated curve for (2:1:2) and (Er')$^{x}$ in the hyperstoichiometric $U_{1-y}$E $r_{y}$ $O_{2＋x}$ and that for (2Er'quot;)$^{x}$ $_{dec}$ in the hypostoichiometric $U_{1-y}$E $r_{y}$ $O_{2－x}$ are in good agreement with the present experimental results. The sintering behavior of Er-doped U $O_2$ is observed with erbium content in oxidizing and reducing atmospheres. For sintering in oxidizing atmosphere, sintered density decreases as increasing y in $U_{1-y}$E $r_{y}$ $O_{2＋x}$. However, in hydrogen atmosphere, sintered density decreases as increasing y at lower erbium content but the density increases again above y=0.10. In oxidizing sintering conditions, the formation of (Er'U')$^{x}$ clusters hinders the diffusion of cations, and hence the sinterability of Er-doped U $O_2$ decreases. In reducing atmosphere of Er-doped U $O_2$ for higher Er concent, the oxygen vacancies make (Er')$^{x}$ cluster decompose by charge compensation and the concentration of mobile cations increases, thereby improving the sinterability.ntration of mobile cations increases, thereby improving the sinterability.ability.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.2
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• pp.195-201
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• 2009

The antioxidative activities of two varieties of egg plant (Chunyang No 2: Dangaji, Jinju Janggaji: Janggaji) extracts were investigated. The total polyphenol contents of Dangaji peel hot water extract and the Janggaji flesh and fruit hot water extracts were higher than those of the other samples. However, the DPPH radical scavenging activities(electron donating activity) of Dangaji flesh-ethanol, peel-cold water, and fruit- ethanol extracts, as well as the Janggaji peel cold water extract, were higher than those of the other samples. Furthermore, the in vitro inhibitory effects of the Dangaji peel cold water and hot water extracts on rat hepatic xanthine oxidase were highest among the samples, and were exhibited in a dose dependant manners. Although there were marked changes in the xanthine oxidase Km values for xanthine as a substrate, the Vmax value changes by the addition of the Dangaji water extracts were minor compared with the control. This result suggests that Dangaji water extracts may regulate the activity of xanthine oxidase-via the inhibition of binding affinity between the enzyme and substrate. The present study provides experimental evidence that constituents of egg plant extracts may ameliorate reactive oxygen species(ROS)-induced oxidative stress via hepatic hepatic xanthine oxidase activity, but further studies to identify the active antioxidants and compounds and inhibitors of xanthine oxidase are required.

• Journal of the Korean Chemical Society
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• v.35 no.6
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• pp.636-644
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• 1991

The cationic polymerization of substituted oxethanes which have pendant energetic groups such as methoxy, azido, and nitrato are investigated theoretically using the semiempirical MINDO/3, MNDO, and AM1 methods. The nucleophilicity and basicity of substituted oxethanes can be explained by the negative charge on oxygen atom of oxetanes. The reactivity of propagation in the polymerization of oxetanes can be represented by the positive charge on carbon atom and the low LUMO energy of active species of oxetanes. The reaction of the energetic cyclic oxonium ion forms to the open chain carbenium ion forms is expected by computational stability energy of the oxonium and carbenium ion (about 10~20 kcal/mole) favoring the carbenium ion. The relative equilibrium concentration of cyclic oxonium and open carbenium ions is found to be a major determinant of mechanism, owing to the rapid equilibrium of these cation forms and the expectation based on clauclation that the prepolymer propagation step SN1 mechanism will be at least as fast as that for SN2 mechanism.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.37 no.1
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• pp.91-96
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• 2011

Deficiency of collagen regeneration, denaturalization of fibers, increased melanin synthesis and reactive oxygen species are important factors inducing deterioration of healthy skin function. They induce freckles and decrease in skin elasticity. Vitamin C, vitamin A and their derivatives have been used as cosmetic ingredients for improvement of these problems but they have various problems. We have been developing the various derivatives of these ingredients. In this study, we investigated whitening effect of 3-o-cetyl-L-ascorbic acid (VCCE), a new vitamin C derivative. The VCCE inhibited melanogenesis in a dose dependent manner(44 % at $20\;{\mu}g/mL $) and tyrosinase expression. For 8 weeks, we also investigated skin brightening effect of VCCE on pigmented spots in UV-irradiated human skin. In results, VCCE showed a statistically significant skin whitening effect by mechanical and visual evaluation. Taken together, our findings suggest that the VCCE has potential benefits as an active ingredient for whitening cosmetics.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.1
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• pp.12-18
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• 2004

Activity of senescence-induced antioxidant enzymes in the detached rice seedlings (Oryza sativa L. cv. Dongjin) was examined. The levels of $\textrm{H}_2\textrm{O}_2$ content and peroxidase (POD) activity were gradually increased during leaf senescence, whereas catalase activity was decreased. The activity of superoxide dismutase (SOD) was increased, and ascorbate peroxidase (APX) and glutathione reductase (GR) were slightly increased until 3d and 4d of dark induced-senescence, and thereafter were decreased. The activation of all SOD isoforms showed a significant decrease after 6d and 7d. After 4d to 7d of dark senescence, there was a significant effect in enhancing the activity of APX-12 and -13 isoforms as compared with light, despite similar levels in total APX activity. GR-8 and -10 isoforms were more effective in leaf senescence at 4d to 7d, particularly with respect to dark-induced senescence. These results suggest that the metabolism of active oxygen species such as $\textrm{H}_2\textrm{O}_2$ is dependent on various functionally interrelated antioxidant enzymes such as catalase, peroxidase, SOD, APX and GR.

• Applied Chemistry for Engineering
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• v.28 no.2
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• pp.221-229
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• 2017

In this study, a wet impregnation method was applied to catalysts based on the active metal Pt in order to confirm the oxidation characteristics of various commercial alumina supports at room temperature. The catalysts were characterized using XPS, CO-chemisorption, and BET. Various $Pt/Al_2O_3$ catalysts controlled the oxygen species of Pt by the electronegativity of electrons and charges when the catalyst was prepared according to the heat treatment conditions. The reason that the dispersion degree decreases with increasing Pt loading seems to be attributed to HT (Huttig Temperature) of Pt. In addition, the minimum hydrogen concentration that can be controlled at room temperature can control hydrogen from metallic Pt up to 1.0 vol% at over 70.09% in the catalyst.

• KSBB Journal
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• v.8 no.2
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• pp.150-155
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• 1993

This study describes biodegradation of dyes which are used in textile industries. Dyes released into the environment from industrial waste water are considered to be a serious pollution problem because of the wide spread into environment with a variety of colors. The microorganisms used in this experiment were Pseudomonas species, which had been screened from aeration tank of waste water treatment. It was found that optimum concentrations for culture media were 14g of glucose, 6g of peptone, 160 mg of Na2HPO4, 200mg of KCl, 140mg of MgSO4,.7H2O,1.0g of KH2PO4, 400mg of NaCl, 200mg of CaCl2 and dye 10ppm per litre of distilled water. The high efficiency of dye degradation was obtained at pH 7-8 and $30-35^{\circ}C$. Strains screened are excellent for removal of azo and reactive dyes, which are relatively stable and difficult to degrade. Dyes of 10ppm such as mono-azo (Lot No. 180), di-azo (Lot No. 138) and reactive red(Lot No. 2) were mostly decolorlzed within 2 days and di-azo (Lot No. 151) and reactive red(Lot No. 34, No. 00166) were decolorized within 5 days in the controlled fermenter. In the case of reactive dyes, oxygen supplies showed lower biodegradability compared to anaerobic culture.

• Journal of the Korean Society of Safety
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• v.33 no.1
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• pp.41-46
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• 2018

Experiments were carried out the phenomenal observation on effect of corona treated hotmelt laminating film in process of manufacture by 2 kinds of rolling speed and electric power variatons. Surface treatment by corona which is exposure of film surface to electron of ion bombardment, rather than mere exposure to active species, like atomic oxygen or ozone, can enhance adhesion by removing contaminant, electret, roughening surface, and introducing reactive chemical group. Reactive neutrals, ions, electron and photons generated during the corona treatment interact simultaneously with polymers to alter surface chemical composition, wettability, and thus film adhesion. However, it is highly recommended that extensive chains scission is avoided because it can lead to side-effect by forming sticky matter, resulting in dropouts. This paper reviews principles of surface preparation of polypropylene substrate by corona discharging. In addition, the experimental section provides a description of parameter optimization on corona discharging treatment and its side-effect. Experimental results are discussed in terms of surface wetting as determined by contact angle and SEM measurements. When the rolling speed of the film decreased from 1.666 [m / sec] to 0.083 [m / sec], contact angle decreased from $80[^{\circ}]$ to $64[^{\circ}]$, and the wettability was greatly improved. As the supply power increased from 0.4 [kVA] to 2 [kVA] at the corona discharge surface treatment, the contact angle decreased from $77[^{\circ}]$ to $65[^{\circ}]$, and the wettability was greatly improved.