• Journal of the Korean Association of Geographic Information Studies
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• v.5 no.2
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• pp.1-15
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• 2002

Atmospheric aerosols interact with sunlight and affect the global radiation balance that can cause climate change through direct and indirect radiative forcing. Because of the spatial and temporal uncertainty of aerosols in atmosphere, aerosol characteristics are not considered through GCMs (General Circulation Model). Therefor it is important physical and optical characteristics should be evaluated to assess climate change and radiative effect by atmospheric aerosols. In this study GMS-5 satellite data and surface measurement data were analyzed using a radiative transfer model for the Yellow Sand event of April 7~8, 2000 in order to investigate the atmospheric radiative effects of Yellow Sand aerosols, MODTRAN3 simulation results enable to inform the relation between satellite channel albedo and aerosol optical thickness(AOT). From this relation AOT was retreived from GMS-5 visible channel. The variance observations of satellite images enable remote sensing of the Yellow Sand particles. Back trajectory analysis was performed to track the air mass from the Gobi desert passing through Korean peninsular with high AOT value measured by ground based measurement. The comparison GMS-5 AOT to ground measured RSR aerosol optical depth(AOD) show that for Yellow Sand aerosols, the albedo measured over ocean surfaces can be used to obtain the aerosol optical thickness using appropriate aerosol model within an error of about 10%. In addition, LIDAR network measurements and backward trajectory model showed characteristics and appearance of Yellow Sand during Yellow Sand events. These data will be good supporting for monitoring of Yellow Sand aerosols.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.3
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• pp.235-241
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• 2009

In this study, the antioxidative effects, inhibitory effects on tyrosinase, elastase of Persicaria perfoliata extracts were investigated. The deglycosylated fraction of extract ($12.38{\mu}g$/mL) showed the most prominent free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity ($FSC_{50}$). Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of P. perfoliata extracts on ROS generated in $Fe^{3+}$-EDTA/$H_2O_2$ system were investigated using the luminol-dependent chemiluminescence assay. The ethyl acetate fraction of extract ($0.35{\mu}g$/mL) showed the most prominent ROS scavenging activity. The protective effects of P. perfoliata extract/fractions on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The P. perfoliata extracts suppressed photohemolysis in a concentration dependent manner ($1{\sim}50{\mu}g$/mL) except the deglycosylated fraction of extract. The inhibitory effect of P. perfoliata extracts on tyrosinase was investigated to assess their whitening efficacy. Inhibitory effects ($IC_{50}$) on tyrosinase were determined with ethyl acetate fraction of P. perfoliata extract ($136.00{\mu}g$/mL) and deglycosylated fraction of extract ($68.10{\mu}g$/mL). Finally, their anti-elastase activities were measured to predict the anti-wrinkle efficacy in the human skin. Inhibitory effects ($IC_{50}$) on elastase were determined with ethyl acetate fraction of P. perfoliata extract ($67.20{\mu}g$/mL) and deglycosylated fraction of extract ($43.50{\mu}g$/mL). These results indicate that extract/fractions of P. perfoliata 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. Extract/fractions of P. perfoliata can be applicable to new functional cosmetics for antioxidant, antiaging.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.3
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• pp.209-217
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• 2009

In this study, the antibacterial activity, antioxidative effects, inhibitory effects on tyrosinase of Inula britannica flower extracts were investigated. MIC values of ethyl acetate fraction from Inula britannica flower on P. acnes 0.25 %, respectively. The results showed that the antibacterial activity of the ethyl acetate fraction was the highest in the P. acnes. The free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activities ($FSC_{50}$) of ethyl acetate fraction of Inula britannica flower was $8.55{\mu}g$/mL. Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of some fInula britannica flower extracts on ROS generated in $Fe^{3+}$- EDTA/$H_2O_2$ system were investigated using the luminol-dependent chemiluminescence assay. The order of ROS scavenging activities were ethyl acetate fraction $0.24{\mu}g$/mL. Ethyl acetate fraction showed the most prominent ROS scavenging activity. The protective effects of extract/fractions of Inula britannica flower on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The Inula britannica flower extracts suppressed photohemolysis in a concentration dependent manner ($5{\sim}100{\mu}g$/mL), particularly deglycosylated flavonoid aglycone fraction exhibited the most prominent celluar protective effect ($\tau_{50}$, 164.15 min at $25{\mu}g$/mL). The inhibitory effect of Inula britannica flower extracts on tyrosinase was investigated to assess their whitening efficacy. Inhibitory effects ($IC_{50}$) on tyrosinase of some Inula britannica flower extracts were high. Ethyl acetate fraction has $IC_{50}$ of $87.03{\mu}g$/mL. These results indicate that extract/fractions of Inula britannica flower 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 ethyl acetate fraction and high potential as bactericide against the skin pathogenic bacteria could be applicable to new functional cosmetics for antioxidant, antiaging, antibacterial activity.

• Journal of the Korean Society of Radiology
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• v.5 no.2
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• pp.73-80
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• 2011

Questionnaires were distributed to Radiology departments at hospitals with 300 sickbeds throughout the Pohang region of North Gyeongsang Province concerning awareness and performance levels of infection control. The investigation included measurements of the pollution levels of imaging equipment and assistive apparatuses in order to prepare a plan for the activation of prevention and management of hospital infections. The survey was designed to question respondents in regards to personal data, infection management prevention education, and infection management guidelines. The ATP Public Heath Monitering System was used to measure seven items for pollution levels of imaging equipment and assistive apparatuses in the Radiology Department. Data was analysed using SPSS version 12.0 for paired t-test and Pearson coefficient with a statistically significant level of 0.05. The results of the survey showed a total awareness level of infection management prevention education averaged at $3.73{\pm}0.64$ and performance levels resulted at $3.39{\pm}0.83$ which were statistically significant (p = 0.01). Also the measurements of pollution levels for equipment with high patient contact showed a Pearson Coefficient of over 0.5 implying a focus on pathogenic bacterium. There was no statistical significance with the frequency of imaging (p < 0.05). Therefore for general hospitals with high patient contact, there is a need to supply analyzing equipment for real time monitoring and the implementation of disinfection management that uses a Ministry of Health and Welfare approved antiseptic solution twice every minute.

• Journal of radiological science and technology
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• v.34 no.1
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• pp.27-33
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• 2011

Along with the developments of science technology, up-to-date medical radiation equipments are introduced. Those equipments has brought many progresses in diagnosing patients not only in the quantitative aspects but in the qualitative ones. Especially, in the case of dental radiography, patients can be exposed more than CT, cone beam computed tomography (CBCT). In this study, we used human phantom and TLD-100H to measure the organ dose in each dental radiography and computed the effective dose according to ICRP (International Committee for Radioactivity Prevention) 60, 103. We measured the effective dose to be 5.1 and $29.5{\mu}Sv$ in the panoramic radiography and 11.2 and $14.4{\mu}Sv$ in the cephalometric radiography respectively. We also executed the CBCT and CT test on the maxillaries and the mandibles and found the amounts of effective dose were 53.7, 209.6, 129, and $391.5{\mu}Sv$ respectively in the CBCT and $93.3{\mu}$, 139.5, 282.7 and $489.7{\mu}Sv$ in the CT test. Consequently, it was shown that the effective dose in the CBCT test was lower than one in the CT test, but was higher in both panoramic and cephalometric radiography.

• Journal of radiological science and technology
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• v.33 no.1
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• pp.61-66
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• 2010

In this paper we evaluated small field dose characteristics of exclusive cone fields versus square fields for stereotactic radiosugery (SRS) which is based on linear accelerators (LINAC). For this test, we used a small beam detector (stereotactic fields detector : SFD) with a 6 MV photon beam and a water phantom system (IBA, Germany). Percentage depth dose (PDD) was measured for different field sets (cones : ${\Phi}1\;cm$, ${\Phi}2\;cm$, ${\Phi}3\;cm$ ; square fields : $1{\times}1\;cm^2$, $2{\times}2\;cm^2$, $3{\times}3\;cm^2$) at a source skin distance (SSD) of 100 cm. We measured the point depths at 1.5 cm, 5 cm, 10 cm, 20 cm, and 30 cm. The output factors were measured under the same geometrical conditions of the PDD and normalized at the maximum dose depth. To analyze the penumbra, we measured the dose profile with 95 cm of SSD, 5 cm of depth for each field sizes (${\Phi}1\;cm$, ${\Phi}3\;cm$, $1{\times}1\;cm^2$, and $3{\times}3\;cm^2$) using SFD. We obtained the values for every 1 mm interval in the physical field (90%) and 0.5 mm interval in the penumbra region (20 to 80%). The PDD variation of exclusive cones and square fields were 4.3 to 7.9% lesser than the standard field size ($10{\times}10\;cm^2$. The variation of PDD was reduced while the field size was increased. To compare the beam quality, we analyzed the $PDD_{20,10}$ and the results showed under the 1% of variations for all experiments except for ${\Phi}1\;cm$ cone and $1{\times}1\;cm^2$ fields. Output factors of exclusive cone were increased 3.1~4.6% than the square fields, and the penumbra region of exclusive cone was reduced 20% as compared to the square fields. As the previous researches report, it is very important for SRS and SFD that precise dosimetry in small beam fields. In this paper, we showed the effectiveness of exclusive cone, compared to square field. And we will study on the various detector characteristics for small beam fields.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.510-518
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• 2003

Protective effects of natural components including genistein (4',5,7-trihydroxyisoflavone) from Glycine max MERRILL on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. Genistein $(10{\sim}100\;{\mu}m)$ suppressed photohemolysis in a concentration-dependent manner, and was more effective than the lipid peroxidation chain blocker, ${\alpha}$-tocopherol (Vit. E). Glycoside of genistein, genistin, the water-soluble antioxidant, L-ascorbate, and the iron chelator, myo-inositol hexaphosphoric acid dodecasodium salt (sodium phytate) did not exhibit protective effect against photohemolysis. L-Ascorbate and sodium phytate stimulated photohemolysis at high concentration $(500\;{\mu}m)$. ${\alpha}$-Carotene 3,3'-diol (lutein), a singlet oxygen $(^1O_2)$ quencher, exhibited pronounced protective effect, an indication that $^1O_2$ is important in photohemolysis sensitized by rose-bengal. Reactive oxygen scavenging activities $(OSC_{50})$ of natural antioxidants including genistein on reactive oxygen species (ROS) generated in $Fe^{3+}-EDTA/H_2O_2$ system using the luminol-dependent chemiluminescence assay were in the order of sodium phytate > L-ascorbate > ${\alpha}$-tocopherol > genistein > genistin. $OSC_{50}$ value of genistein, genistin, ${\alpha}$-tocopherol, L-ascorbate, and sodium phytate were 41.0, 109.0, 9.0, 5.2, and $0.56{\mu}m$ respectively. The order of free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity $(FSC_{50})$ was L-ascorbate > ${\alpha}$-tocopherol > genistein > genistin. These results indicate that genistein can function as an antioxidant in biological systems, particularly skin exposed to solar UV radiation by scavenging $^1O_2$ and other ROS, and to protect cellular membranes against ROS.

• Food Science and Preservation
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• v.15 no.4
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• pp.582-586
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• 2008

Total phenolic compounds and antioxidative activities of rooibos tea(Aspalathus linearis) fractions were studied. Three extracts, using hexane, ethyl acetate, and ethanol, were prepared. Total phenolic compounds were 3069.3 mg/100 g extract in the hexane fraction, 18604.4 mg/100 g extract in the ethyl acetate fraction, and 13458.8 mg/100 g extract in the ethanol fraction. Levels of vanillic acid, caffeic acid, syringic acid, 4-coumaric acid, and ferulic acid were analyzed by RP-HPLC, and totals of 3452.6 and 3156.1 mg/100 g of extract were found in the ethanol and ethyl acetate fraction, respectively. In the DPPH assay, the ethanol fraction(82.2% of contol) and the ethyl acetate fraction(78.9%) showed the highest free radical scavenging capacities. The induction period of each tea fraction in the fish oil rancimat assay was measured. When 500 ppm of the ethanol fraction was applied, a 1.19 h induction period was observed. This was 2-fold greater than the induction period of the control.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.3
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• pp.257-264
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• 2006

This study investigated the effects of hybrid process(chemical coagulation, Fenton oxidation and ceramic UF(ultrafiltration)) on COD and color removals of commercial reactive dyestuffs. In the case of chemical coagulation, the optimal concentrations of $Fe^{3+}$ coagulant for COD and color removals of RB49(reactive blue 49) and RY84(reactive yellow 84) were determined according to the different coagulant dose at the optimal pH. They were 2.78 mM(pH 7) in RB49 and 1.85 mM(pH 6) in RY84, respectively. In the case of Fenton oxidation, the optimal concentrations of $Fe^{3+}\;and\;H_2O_2$ were obtained. Optimal $[Fe^{2+}]:[H_2O_2]$ molar ratio of COD and color removals of RB49 and RY84 were 4.41:5.73 mM and 1.15:0.81 mM, respectively. In the case of ceramic UF, the flux and rejection of supernatant after Fenton oxidation were investigated. After ceramic UF for 9 hr, the average flux of RB49 and RY84 solutions were $53.4L/m^2hr\;and\;67.4L/m^2hr$ at 1 bar, respectively. In addition, the permeate flux increased and the average flux recovery were 98.5-99.9%(RB49) and 91.0-97.3%(RY84) according to adopting off-line cleaning(5% $H_2SO_4$). Finally, COD and color removals were 91.6-95.7% and 99.8% by hybrid process, respectively.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.2
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• pp.117-127
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• 2008

In this study, the antioxidative effects, inhibitory effects on elastase, and components of Cayratia japonica extracts were investigated. The free radical(1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activities($FSC_{50}$) of extract/fractions of Cayratia japonica were in the order: 50% ethanol extract(114.3 ${\mu}g/mL$)${\mu}g/mL$)${\mu}g/mL$). Reactive oxygen species(ROS) scavenging activities($OSC_{50}$) of some Cayratia japonica extracts in $Fe^{3+}-EDTA/H_2O_2$ system were investigated using the luminol-dependent chemiluminescence assay. The order of ROS scavenging activities were deglycosylated flavonoid aglycone fraction($OSC_{50},\;3.30{\mu}g/mL$)<50% ethanol extract(1.21 ${\mu}g/mL$)${\mu}g/mL$). Ethyl acetate fraction showed the most prominent scavenging activity. The protective effects of extract/fractions of Cayratia japonica on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The Cayratia japonica extracts suppressed photohemolysis in a concentration dependent manner($1{\sim}25{\mu}g/mL$), particularly deglycosylated flavonoid aglycone fraction exhibited the most prominent celluar protective effect(${\tau}_{50}$, 175.05min at 25 ${\mu}g/mL$). Aglycone fractions obtained from the deglycosylation reaction of ethyl acetate fraction among the Cayratia japonica extracts, showed 2 bands in TLC and 2 peaks in HPLC experiments(360 nm). Two components were identified as luteolin(composition ratio, 47.50%), apigenin(52.50). TLC chromatogram of ethyl acetate fraction of Cayratia japonica extract revealed 3 bands and HPLC chromatogram showed 4 peaks, which were identified as luteolin-7-O-${\beta}$-D-glucopyranoside(composition ratio, 11.14%), apigenin-7-O-${\beta}$-D-glucuronopyranoside(15.38%), luteolin(23.55%) and apigenin(49.92%) in the order of elution time. The inhibitory effect of aglycone fraction on elastase($IC_{50},\;70.5{\mu}g/mL$) was very high. These results indicate that extract/fractions of Cayratia japonica 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 component analysis of Cayratia japonica extract and antioxidative effects could be applicable to new cosmetics.