• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.5
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• pp.691-699
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• 1997

The effects of concave hemispherical surface curvature on the local heat transfer from a turbulent round impinging jet were experimentally investigated. The liquid crystal transient method was used for these measurements. This method, which is a variation on the transient method, suddenly exposes a preheated wall to an impinging jet while video recording the response of liquid crystals for the measurement of the surface temperature. The Reynolds number ranges from Re=11,000 to 50,000, the nozzle-to- surface distance from L/d=2 to 10, and the surface curvature from D/d=6 to 12.The present results are also compared to those for the flat plate case. In the experiment, the local Nusselt numbers tend to increase in all regions with an increasing surface curvature. The maximum Nusselt number for all Reynolds numbers occurred at L/d .ident. 6 and a second maximum in the Nusselt number occurred at R/d .ident. 2 for both Re=23,000 and Re=50,000 in the case of L/d=2 and for Re=50,000 only in the case of L/d=4. Meanwhile, as the surface curvature increases, the value of the secondary maximum Nusselt number decreases. All the other cases exhibit monotonically decreasing values of the Nusselt number along the curved surface. The stagnation point Nusselt numbers are well correlated with Re, L/d, and D/d.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.2
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• pp.157-165
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• 2010

In this study, the antioxidative effects, inhibitory effects on tyrosinase and elastase of Rhododendron brachycarpum D. Don extracts were investigated. And the moisturizing effect of cream containing R. brachycarpum D. Don extract were investigated by clinical trial. The ethyl acetate fraction of R. brachycarpum D. Don extract (1.83 ${\mu}g/mL$) showed the most prominent the free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity ($FSC_{50}$). Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of R. brachycarpum D. Don extracts on ROS generated in $Fe^{3+}$-EDTA/$H_2O_2$ system were investigated using the luminol-dependent chemiluminescence assay. The 50 % extract fraction (0.064 ${\mu}g/mL$) showed the most prominent ROS scavenging activity. The protective effects of extract/fractions of R. brachycarpum D. Don on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The R. brachycarpum D. Don extracts suppressed photohemolysis in a concentration dependent manner (1 ~ 10 ${\mu}g/mL$). The inhibitory effects ($IC_{50}$) of R. brachycarpum D. Don extracts on tyrosinase were determined with ethyl acetate fraction of R. brachycarpum D. Don extract (70.5 ${\mu}g/mL$) and aglycone fraction of extract (122.40 ${\mu}g/mL$). The inhibitory effects ($IC_{50}$) on elastase were determined with ethyl acetate of R. brachycarpum D. Don extract (43.50 ${\mu}g/mL$) and aglycone fraction of extract (20.73 ${\mu}g/mL$). The cream containing the ethyl acetate fraction of R. brachycarpum D. Don extracts was formulated for skin hydration effect and transepidermal water loss (TEWL). The cream containing R. brachycarpum D. Don extract was applied to the right lower arm. After 180 min, the water contents in skin were increased by 1 ~ 4 % than the placebo cream. And TEWL of parts was decreased as 7.7 $g/m^2h$ (experimental cream) and 8.9 $g/m^2h$ (placebo cream) respectively. These results indicate that extract/fractions of R. brachycarpum D. Don can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against ROS. And inhibitory activity on tyrosinase of the aglycone fraction could be applicable to new functional cosmetics for whitening and anti-wrinkle products. Also the increase of skin hydration of the cream containing extract could be applicable to new functional cosmetics for antiaging.

• Korean Journal of Breeding Science
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• v.43 no.1
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• pp.50-55
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• 2011

The introduction of doubled haploid (DH) approach into breeding programs has reduced the times and population sizes required for the production of pure lines. We carried out the experiment for development on effective method of producing haploid in wheat. Emasculated spikelets of wheat were pollinated with maize pollen and cultured in the solution containing 40 g/L sucrose and 2,4-D, NAA, 2,4,5-T and dicamba 24 h after pollination, and then incubated until embryo rescue. Fourteen to sixteen days after pollination, the embryos are excised and cultured in half-strength MS basal medium supplemented with 20 g/L sucrose and 1 mg/L NAA. The type of plant growth regulators was found to be most significant in production of haploid plants. The application of synthetic auxins to pollinated florets, stimulates haploid embryo development to a stage where the embryos can be rescued onto nutrient media. The percentage of seeded florets was significantly affected by 100 mg/L 2,4-D, 150 mg/L 2,4,5-T and 50 mg/L dicamba. The percentage of embryos formed was significantly increased by treatment with 2,4-D and 2,4,5-T at 100 mg/L, and dicamba at 50 mg/L, but the treatments with 150 mg/L 2,4-D inhibited embryo development and plant regeneration. The optimum application time of plant growth regulators was 24 hrs after pollination.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.1
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• pp.1-8
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• 2013

In this work, comparative study on antioxidative activities of extracts from Glycyrrhiza uralensis (G. uralensis) produced in Korea and in China and Glycyrrhiza glabra (G. glabra) produced in Uzbekistan was conducted. Among three origins, 50% ethanol extracts (21.15 ${\mu}g/mL$), ethyl acetate fraction (29.15 ${\mu}g/mL$) and aglycone fraction (3.26 ${\mu}g/mL$) of G. uralensis from Korea showed the higher free radical (1,1-phenyl-2-picrylhydrazyl, DPPH) scavenging activity ($FSC_{50}$) than extracts from other origins. Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of extracts from three origins on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system were investigated using luminol-dependent chemiluminescence assay 50% ethanol extract (1.00 ${\mu}g/mL$) and ethyl acetate fraction (0.34 ${\mu}g/mL$) of G. uralensis from China showed the most prominent ROS scavenging activity. The protective effects of extract/fractions of G. uralensis and G. glabra extracts on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. 50% ethanol extract and aglycone fraction of G. uralensis and G. glabra extracts from three origins showed cellular protective effects in a concentration dependent manner (5 ~ 50 ${\mu}g/mL$). Aglycone fraction of G. uralensis from Korea (${\tau}_{50}$ = 847.4 min)especially showed cellular protective effects four times higher than that from China (${\tau}_{50}$ = 194.3 min). These results indicate that G. uralensis and G. glabra extracts, which have been used as whitening agent, could be applicable to functional cosmetic ingredient as a natural antioxidant. Judging from the prominent cellular protecitve effects, it is concluded that G. uralensis and G. glabra extracts can protect the skin from $^1O_2$ and various ROS induced by UV.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.3882-3888
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• 2015

The present study was conducted to assess the relationship between obesity and abdominal obesity and Parathyroid hormone (PTH) in adults aged 50 or older (n=3,305) using 2011 Korean National Health and Nutrition Examination Survey (KNHANES) data, which represents national data in Korea. Key study results were as follows: First, the PTH levels increased significantly with an increase in Body mass index (BMI) (p=0.003), shown by sIAD levels after adjusted the variables that affect sIAD levels (age, gender, SBP, DBP, and 25(OH)D). These were $66.25{\pm}0.89ng/dL$ for Normal weight (BMI, < $23.0kg/m^2$), $67.83{\pm}1.07 ng/dL$ for Overweight (BMI, $23.0-24.9kg/m^2$), $70.71{\pm}0.94ng/dL$ for Obesity (BMI,${\geq}25.0kg/m^2$). Second, the PTH level of abdominal obesity group ($69.30{\pm}0.80ng/dL$) was significantly higher (p=0.017) than non-abdominal obesity group ($66.63{\pm}0.74ng/dL$). In conclusion, BMI and waist measurement are positively associated with the PTH levels in Korean adults.

• Korean Journal of Plant Resources
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• v.25 no.2
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• pp.176-183
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• 2012

This study was carried out to develop ferns as the natural antioxidant materials by graduating and extracting fronds of $Dryopteris$ $crassirhizoma$, $Dryopteris$ $nipponensis$, and $Polystichum$ $lepidocaulon$, which belong to Dryopteridaceae, using solvent, and analyzing the antioxidant effect of each fraction. The n-butanol fraction of $D.$ $crassirhizoma$ (550.0 $mg{\cdot}g^{-1}$), the ethyl acetate fraction of $D.$ $nipponensis$ (374.8 $mg{\cdot}g^{-1}$), and the n-butanol fraction of $P.$ $lepidocaulon$ (781.8 $mg{\cdot}g^{-1}$) showed relatively higher total contents of polyphenol. The chloroform fraction of $D.$ $crassirhizoma$ (72.9 $mg{\cdot}g^{-1}$), and the n-hexane fraction of $D.$ $nipponensis$ (72.9 $mg{\cdot}g^{-1}$) and $P.$ $lepidocaulon$ (154.5 $mg{\cdot}g^{-1}$) contained relatively higher total contents of flavonoids. DPPH radical scavenging activity was most excellent in the n-butanol fraction of $D.$ $crassirhizoma$ ($RC_{50}=0.02mg{\cdot}mL^{-1}$) and $P.$ $lepidocaulon$ ($RC_{50}=0.04mg{\cdot}mL^{-1}$), and the water fractions of $D.$ $nipponensis$ ($RC_{50}=0.01mg{\cdot}mL^{-1}$). ABTS radical scavenging activity was potent in the n-hexane and n-butanol fractions of $D.$ $crassirhizoma$ (each $RC_{50}=0.02mg{\cdot}mL^{-1}$), the ethyl acetate fraction of $D.$ $nipponensis$ ($RC_{50}=0.03mg{\cdot}mL^{-1}$), and the n-butanol fraction of $P.$ $lepidocaulon$ ($RC_{50}=0.06mg{\cdot}mL^{-1}$). There was the large amount of total polyphenol content in the n-butanol fraction of $D.$ $crassirhizoma$ and $P.$ $lepidocaulon$, and their radical scavenging activities were potent. Therefore, it was thought that biologically active substances of each fraction layer are required to be analyzed and used.

• Journal of the Korean Applied Science and Technology
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• v.37 no.6
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• pp.1545-1555
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• 2020

In the present study, we investigated the antioxidant activity of Aucklandia lappa Decne (AL). Cell viability was measured in an MTT assay. Antioxidant effects were evaluated based on total polyphenol/flavonoid contents, ABTS radical scavenging activity, DPPH radical scavenging activity, SOD activity, and ROS content. AL was found not to be toxic at concentrations of 1 ㎍/mL, 10 ㎍/mL, and 100 ㎍/mL, respectively. The phenolic content was higher in AL-D than in AL-E, while the flavonoid content was higher in AL-E than in AL-D. AL-E exhibited higher ABTS radical scavenging activity than AL-D, and the EC50 values for BHA were 217.1 ㎍/mL in AL-D and 180.5 ㎍/mL in AL-E. AL-E also showed the highest DPPH radical scavenging activity. EC50 values for BHA were 114.2 ㎍/mL in AL-D and 95.8 ㎍/mL in AL-E. The SOD-like activity of AL-E was higher than that of AL-D. The EC50 values for ascorbic acid were 48.5 ㎍/mL in AL-D and 72.9 ㎍/mL in AL-E, indicating that both AL extracts have a SOD activity higher than that of ascorbic acid. AL-E reduced relatively more ROS than AL-D. With 100 ㎍/mL AL-E, the reduction level was almost similar to that of dexamethasone. Our results demonstrate that AL have antioxidant effects, and we believe that they could be very valuable as raw materials for anti-aging products, based on their antioxidant activity.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.36 no.5 s.108
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• pp.53-61
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• 2004

[ $Poly(_{D}-ldactide)\;(_{D}-PLA)$ ] was synthesized to have low molecular weight for miscible blends with a high molecular $poly(_{L}-lactide)\;(_{L} -PLA)$. The blends were prepared by dissolving the two components of $_{L}-PLA\;and\;_{D}-PLA\;(w/w)$ in chloroform (l00/0, 90/10, 70/30, 50/50, 30/70, 0/100). The miscibility of these miscible blends was characterized by gel-permeation chromatography (GPC), differential scanning calorimetry (DSC), and the selective degradability by enzymes (proteinase K, subtilisin and $\alpha$-chymotrypsin). The coating efficiency of PLA blends onto paper was determined and the degrading activity cellulases by on these blends. The miscibility, coating efficiency and enzymatic degradability of these blends were decreased according to increasing of $_{D}-PLA$ blending part. Such results were attributed to the extent of coating application of PLA, with better miscibility (compatibility), coating efficiency and degradability due to a higher $_{L}-PLA$ content.

• Journal of Applied Biological Chemistry
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• v.58 no.3
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• pp.197-199
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• 2015

The composition of the essential oil of Ligustrum japonicum leaves was determined by GC-MS analysis. The major constituents of L. japonicum leaf oil were germacrene D (40.50%), ${\alpha}$-pinene (13.63%), (-)-${\beta}$-elemene (6.42%), ${\beta}$-caryophyllene (5.73%), and $\delta$-cadinene (5.47%). The acaricidal activities of L. japonicum oil were evaluated against acaridae and pyroglyphid mites. In the fumigant bioassay, the $LD_{50}$ values of L. japonicum oil were 16.48, 12.38, and $15.63{\mu}g/cm^3$ against Tyrophagus putrescentiae, Dermatophagoides farinae, and D. pteronyssinus, respectively. In the contact bioassay, the $LD_{50}$ values of L. japonicum oil were 8.02, 5.02, and $7.67{\mu}g/cm^2$ against T. putrescentiae, D. farinae, and D. pteronyssinus, respectively.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.133-137
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• 2010

Purpose: The main function of vitamin D is the mineralization of the brain by increase of calcium and phosphorus, in case it is insufficient in children, lime deposition on cartilage cannot occur so it leads to rachitis, and in adults, it leads to osteomalacia or osteoporosis. It is also strongly believed in the academic world that vitamin D can restrict the growth of cancer cells and prevent heart diseases, which is also somewhat proven in epidemiological researches. While the right density of vitamin D is still being studied, 20-32 ng/mL is believed to be the most ideal density. Therefore, I wanted analyze how much density of 25-Hydroxyvitamin D3 that Koreans possess. Materials and Methods: From February 20th, 2008 to April 21st, 2009, the collection of 2800 serums, from medical examination treated subjects by Neodin Medical Institute, have been tested. The targets were tested by 25-Hydroxyvitamin D (125I Kit: Diasorin, USA), and were analyzed by dividing into many different categories (gender, age, season, region). Results: The average density of male were 20 ng/mL, female 17.08 ng/mL. Per age groups, the density of males were as follows: 10~20-18 ng/mL, 21~30-17 ng/mL, 31~40-19 ng/mL, 41~50-21 ng/mL, 51~60-22 ng/mL, 61~70-22 ng/mL, 71~80-22 ng/mL and 81~90-19.9 ng/mL. Average density of females per age groups, were as follows: 10~20-16 ng/mL, 20~30-15.26 ng/mL, 30~40-16 ng/mL, 40~50-17 ng/mL, 50~60-19 ng/mL, 60~70-19 ng/mL, 70~80-19 ng/mL, and 80~90-17 ng/mL. Per seasons, From December to May, the subjects showed the density of 15.97 ng/mL, while from June to November, it showed 21.60 ng/mL. On density of males from January to April regionally, Seoul+Gyeonggi-Do-15.52 ng/mL, Gangwon-Do-15.33 ng/mL, Choongchung-Do-18.03 ng/mL, Jeonla-Do-18.68 ng/mL, Gyungsang-Do-18.76 ng/mL and Cheju Do-21.23 ng/mL. Conclusions: The vitamin D of Koreans is has been insufficient compared to the suggested amount. Ultraviolet rays, which is the main source of vitamin D is critical, therefore it is suggested that more outdoor activities can definitely help.