• Analytical Science and Technology
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• v.12 no.6
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• pp.528-533
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• 1999

The total iodine is determined in serum, fresh milk and feed additive by ICP-MS. The preparation involves only a 25-fold dilution with a diluent by direct nebulization in the plasma. The diluent composition is $NH_4OH$(0.5% v/v)+$CH_3OH$(5% v/v) and the abundance of iodine is measured at m/z=127. The calibration curve was linear over the ranges $0-100{\mu}g/L$ with $R^2=0.99$ for iodine. The detection limit of this method is $0.084{\mu}g/L$ for iodine. The relative error range of milk powder SRM in optimum condition is 2.30%-4.73%. The concentration ranges of iodine in the serum, fresh milk, feed additive were $12.4-40.2{\mu}g/L$, < 0.01-3.11 mg/L, < $10^{-7}-2.60g/kg$ respectively.

• Korean Journal of Pharmacognosy
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• v.33 no.4 s.131
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• pp.399-403
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• 2002

Three melanogenesis inhibitors were isolated from the roots and rhizomes of Veratrum nigrum L. and were identified as (3S,20S,25S)-22,26-iminocholesta-5,22(N)-dien-3-ol (verazine), (3S,2OR,25S)-22,26-iminocholesta-5,22(N)-dien-3-ol (epi-verazine) and (3R,23R)-14,15,16,17- tetradehydroveratraman-3,23-diol (veratramine) on the basis of their spectroscopic data. It was turned out that these compounds did not directly inhibit tyrosinase activity, the key enzyme responsible for the formation of melanin pigment while these compounds showed strong inhibition on the melanogenesis in B16 F1 mouse melanoma $(IC_{50}<1\;{\mu}g/ml)$. Due to the strong inhibitory activity and safety compared to current whitening agents such as arbutin, kojic acid and AHA, the compound can be a good candidate for new skin whitening agents.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.2
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• pp.101-107
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• 2008

In order to investigate the potential of a Angelica keiskei Koidzumi extract and its fractions as an active ingredient for whitening cosmetics, we prepared Angelica keiskei Koidzumi extract(70% ethanol), and the aqueous suspension was successively extracted with hexane, ethyl acetate(EA), and n-butanol fraction. We measured their inhibitory effects on mushroom tyrosinase and melanin synthesis in B16 melanoma cells and normal human kerationocytes in vitro. They did not show inhibitory activity against mushroom tyrosinase and the melanin synthesis except hexane and EA fractions. Hexane and EA fractions markedly inhibited cellular tyrosinase activity at a lower concentration(25 and 5 ${\mu}g/mL$, respectively) than arbutin(250 ${\mu}g/mL$). We also quantified the released amount of endothelin-1(ET-1), a mitogen of melanocyte, and interleukin-$1{\alpha}$(IL-$1{\alpha})$, a mediator of UVB-induced inflammation. Hexane and EA fractions did not affect IL-$1{\alpha}$ production, but they decreased UVB-induced ET-1 production in normal human keratinocytes in a dose dependant manner. As a result, hexane and EA fractions could inhibit the melanogenesis through the inhibition of UVB-induced ET-1 production in normal human keratinocytes. This result suggests that hexane and EA fractions of Angelica keiskei Koidzumi extract could be used as an active ingredient for cosmetics.

• Microbiology and Biotechnology Letters
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• v.32 no.3
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• pp.243-248
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• 2004

Production of (R)-3-hydroxybutyric acid (R3HB) by fed-batch culture and continuous culture of metabolically engineered Escherichia coli harboring Ralstonia eutropha PHB biosynthesis and depolymerase genes was examined in a 30 1 pilot-scale fermentor. A new stable two-plasmid system, pBRRed containing the R. eutropha PHB depolymerase gene and pMCS 105 containing the R. eutropha PHB biosynthesis genes, was developed. Among a variety of E. coli strains harboring plasmids, recombinant E. coli XL-10 Gold (pBRRed, pMCS105) was able to produce R3HB with the highest efficiency in a batch culture. By the fed-batch culture of recombinant E. coli XL-10 Gold(pBRRed, pMCS 105) in a 30 1 fer-mentor, the final R3HB concentration was 22.4 g/l giving a productivity of 0.97 g/l-h. To produce R3HB to a high concentration with high productivity, a new strategy of fed-batch culture followed by a continuous culture was investigated. The maximum productivity and R3HB concentration were 5.06 g/l-h and 25.3 g/l, respectively. These results show that economical production of R3HB is possible by recombinant E. coli in large scale.

• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.154-163
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• 1989

This studies were designed to improve the productivity of L-lysine by protoplast fusion and immobilized system of fusants using strains of Brevibacterium flavum ATCC 21528, Brevibacterium lactofermentum ATCC 21086 and Corynebacterium glutamicum 820. Mutants were isolated with concentration method of $300{\mu}g/ml$ penicillin-G after treatment of $250{\mu}g/ml$ N-methyl-N-nitro-N-nitrosoguanidine. B. flavum $37-2(Hos^-,\;Kan^r,\;AEC^r)$, B. lactofermentum $6-2(Ile^-,\;Val^-,\;Str^r,\;AEC^r)$ and C. glutamicum 57-5$(Met^-,\;Thr^-,\;Rif^r,\;AEC^r)$ were isolated from mutants. Protoplasts were induced by being incubated with $500{\mu}g/ml$ lysozyme of lysis solution for 6 hr and the ratio of protoplast formation and regeneration were ranging from 97-99% and 33-37%, respectively. Fusion frequencies of fusants of BBFL 21, BCFG 37 and BCLG 59 were shown in the range from $1.25{\times}10^{-6}\;to\;5.83{\times}10^{-7}$ under the optimum conditions. The fusant BBFL 21 showed the highest productivity of $411.1\;ng/ml{\cdot}hr$ L-lysine in the lysine productivity broth at $30^{\circ}C$ for 72hr. In the immobilization systems, fusant BBFL 21 was employed in various polymer matrices such as sodium alginate, polyacrylamide, agar and ${\alpha}-carrageena$. The immobilization of sodium alginate showed the highest productivity of $413\;ng/ml{\cdot}hr$ L-lysine in the batch system. Continuous fermentation of immobilization system by using tube fermentor was produced the highest productivity $416.7\;ng/ml{\cdot}hr $ L-lysine under optimum condition.

• Journal of Korean Society of Water and Wastewater
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• v.14 no.3
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• pp.271-280
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• 2000

This study was conducted to determine the applicable loading rate and to evaluate the possibility of using limestones as an alkalinity source for the removal of ${NO_3}^{-}-N$ remaining after denitrification/nitrification process with the down-flow sulfur packed bed reactor(SPBR). The pretreated sewage was fed to SPBR. Three SPBRs were filled with elemental sulfur particles and limestones and the volumetric ratios of sulfur to limestone were 0%, 12.5% and 25% for R-0%, R-12.5% and R-25%, respectively. The applicable loading rate was evaluated increasing flow rate with influent ${NO_3}^{-}-N$ concentration of 20 mg/L. For R-0% with external alkalinity supply, denitrification efficiency was greater than 96% up to loading rate of $354.8g\;{NO_3}^{-}-N/m^3{\cdot}day$, and corresponding EBCT was 1.4hr. For R-12.5% and R-25%, where alkalinity was supplied by the limestone filled in the reactor, denitrification efficiency was greater than 94% up to loading rate of $283.8g\;{NO_3}^{-}-N/m^3{\cdot}day$, and corresponding EBCT was 1.7hr. The slightly better performance of R-12.5 compared to R-25 suggests that the volumetric sulfur to limestone ratio of 12.5% was enough for the supply of alkalinity required for sulfur-utilizing denitrification. DO was appeared not showing inhibitory effect on sulfur-utilizing denitrification. The clogging of SPBR caused by the produced gas can effectively be eliminated by regular introduction of treated water in up-flow mode.

• Journal of Nutrition and Health
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• v.51 no.4
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• pp.287-294
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• 2018

Purpose: This study was conducted to evaluate the association between serum 25-hydroxyvitamin D (25(OH)D) levels and dental caries experience in Korean adolescents based on the 2010 ~ 2014 Korean National Health and Nutrition Examination Surveys. Methods: The study subjects were 2,655 Korean adolescents aged 10 to 18 years. Subjects were classified into four groups according to their serum 25(OH)D levels. We used logistic regression to evaluate the relationship between vitamin D and for dental caries experience after adjusting for age, household income level, recipient of basic livelihood, tooth brushing and visiting dental clinics. Result: Multiple logistic regression analysis showed that serum 25(OH)D insufficiency (20 ng/mL ${\leq}25(OH)D$ < 30 ng/mL) was associated with increased odd ratios (ORs) for dental caries experience in boys (OR = 2.577, 95% CI = 1.013-6.557), compared with serum 25(OH)D sufficiency (25(OH)D ${\geq}30ng/mL$). Conclusion: The serum 25(OH)D levels were found to be related to risk of dental caries experience in Korean adolescent boys.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.4
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• pp.363-369
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• 2007

The objective of this study was to investigate the variation of Chinese milk vetch(Astragalus sinicus L.; CMV) seed quality after flowering. We tagged individual open flowers of CMV at the day of maximum flowering(11 May) in Seoul, Korea. Seed samples were harvested serially at 15, 20, 25 and 30 days after flowering(DAF). To compare with dried seeds, non-dried seeds were tested immediately after harvest and the remaining seeds were placed at room temperature for 4 weeks. Seed length, 1000 seed weight, moisture content, germination rate(GR), mean germination time(MGT), germination speed(GS), germination performance index(GPI) and physical dormancy rate(PDR) were investigated. Seed length increased to 2.6 mm and 1000 seed weight reached up to 2.2 g until 25 DAF. Seed moisture content dramatically decreased from 20 to 25 DAF. Moisture content of non-dried seed(7.5%) was similar to that of dried seed(5.5%) at 25 DAF. The rate of seed viability reached up to 94% at 25 DAF. In case of dried seed, GR increased up to 39% at 25 DAF whereas GR of non-dried seed varied from 5 to 10%. GS and GPI of dried seed were significantly higher than those of non-dried seed since 25 DAF. PDR of dried seed has decreased since 20 DAF, whereas PDR of non-dried seed has increased. GR, GS and GPI increased as PDR decreased. Our results evidenced that PDR might be one of major factor in variation of seed quality, of which development was completed at 25 DAF.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.1
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• pp.117-123
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• 2011

This study aims to suggest a suitable soil thickness and soil mixture ratio of a green roof system by verifying the growth of Chrysanthemum zawadskii var. coreanum as affected by different green roof systems using rainwater. The experimental planting grounds were made with different soil thicknesses(15cm, 25cm) and soil mixing ratios (SL, $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$, $P_4P_4L_2$) and with excellent drought tolerance. Ornamental value Chrysanthemum zawadskii var. coreanum was planted. The change in plant height, green coverage ratio, chlorophyll content, fresh weight, dry weight, and dry T/R ratio of Chrysanthemum zawadskii var. coreanum were investigated from April to October 2009. For 15cm soil thickness, the plant height of Chrysanthemum zawadskii var. coreanum was not significantly different as affected by the soil mixing ratio. However, it was found to be higher in the amended soil mixture, $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$ and $P_4P_4L_2$ than in the sandy loam soil, as it was SL overall. For 25cm soil the plant height differences were in order to SL < $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$ < $P_4P_4L_2$. The green coverage ratio was observed not to be different by soil mixing ratio with soil thickness of 15cm, but, the lowest green coverage ratio in the SL. In the 25cm soil thickness, the green coverage ratio was 86-89% with a good coverage rate overall. The change in chlorophyll contents with 15cm soil thickness was found to be the highest in the SL treatment and the lowest in the $P_5P_3L_2$ treatment. For 25cm thickness, the highest value was in the $P_4P_4L_2$ and SL, and the lowest in the$P_7P_1L_2$. Fresh weight and dry weight were larger in soil with 25cm thickness. Therefore, the growth of Chrysanthemum zawadskii var. coreanum as affected by a different green roof system for using rainwater was higher in soil with 25cm thickness than 15cm, and in PPL amended soil than in sandy loam.

• Korean Journal of Food Science and Technology
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• v.40 no.6
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• pp.649-655
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• 2008

In this study, the characteristics of the lactic fermentation of gamju manufactured using a medicinal herb decoction were assessed. A bacterial strain, LAB19, which is used for the induction of lactic fermentation into gamju, was isolated from dried persimmon and identified as Leuconostoc mesenteroides on the basis of morphological, physiological, and chemotaxonomical features, and 16S rRNA sequencing analysis. After 60 hours of lactic fermentation with Leuconostoc mesenteroides LAB19 at $25^{\circ}C$, the gamju was determined to contain 141.3 g/L of reducing sugar, 5.33 g/L of acids, and 1.19 g/L of soluble phenolics. Approximately 90% of reducing sugar and 58% of acids were maltose and lactic acid, respectively. Free radical scavenging activities were retained at levels between 76.6 to 75.7% during the lactic fermentation of gamju.