• Journal of the Korean Society of Radiology
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• v.9 no.2
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• pp.67-72
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• 2015

In diagnostic radiology, the use of automatic exposure control device is internationally recommended for diagnosis and optimization. However, if exposed to prolonged radiation is a complicated manufacturing process, there is a problem that occurs decrease of various performance overall brightness sensor, which is commercially available conventional. Therefore, in this study, absorption of X-ray is high, and I want to evaluate the AEC applicability of the sensor of the photoconductor-based production has an easy advantage. Experimental results confirms the possibility of fabrication of the sensor through an increase in the SNR, with the detection efficiency superior, accurate turn-off. In addition, it is confirmed that the experimental results of the transmittance and the latent image, Ghost effect by the light conductor does not appear, in the case of a photoconductor with the exception of the PbO, 80% - and it was confirmed good transmittance of 90%. Therefore, excellent mechanical stability and poor performance due to a change of the doping concentration than the existing products that have been put to practical use, the sensor easy photoconductor based, fabrication and can be applied as AEC sensor is expected.

• The Korean Journal of Food And Nutrition
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• v.26 no.3
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• pp.565-572
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• 2013

This study was performed to optimize the processing conditions and to select the optimum species for colored sweet potato chips (Shinjami, Juhwangmi and Hayanmi varieties) baked by far-infrared radiation. Sweet potato chips were prepared by different slicing thickness (1~3 mm), concentration of sucrose solution for soaking (15~30%), blanching time (15~60 sec), baking temperature ($110{\sim}140^{\circ}C$) and baking time (23~31 min) through sensory evaluation and failure stress measurement. Optimal processing condition of sweet potato chips using Shinjami was determined to 1 mm, 20%, 45 sec, $120^{\circ}C$ and 31 min, and those using Juhwangmi was determined as 1 mm, 25%, 45 sec, $130^{\circ}C$ and 29 min. Sweet potato chips using Hayanmi was determined as 1 mm, 20%, 45 sec, $120^{\circ}C$ and 31 min, respectively. Free sugar content of sweet potato chips was higher in chips than in raw materials. In the sensory evaluation, appearance, sweet taste, hardness, and overall acceptance were higher in Juhwangmi than in the Shinjami and Hayanmi varieties. Overall acceptance, sugar content, b-value and failure stress were highly correlated among factors affecting the sensory characteristics (p<0.01). From the results of this study, Juhwangmi variety was selected for production of sweet potato chips.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.5
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• pp.1204-1212
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• 2005

Lung cancer is one of the common malignant tumors in the world. It occurs more increasingly due to the serious air pollution, heavy smoking, expoure to ionized radiation, pollution with heavy metal, and owing to well advanced diagnostic skill, etc. Also lung cancer has the limitation of medical care because metastasis is already shown up in more than half cases when it is first detected through medical examination. Although it is treated with chemoradiation, the rate of deaths from lung cancer is high as well, because blood has a lot of toxicity which give side effects. So it has a low rate of cure. So, the ways of various treatment is being researched to raise the rate of care and decrease the side effects recently, and one of the results is inducing apoptosis which makes use of molecularbiologic diagnosis of lung cancer's cell and using oriental medicine drugs. The purpose of this study is whether apoptosis would happen on the human lung carcinoma cell by treated with Junglyeokdaejosape-tang, Junglyeok-tang Junglyeokdaejosape-tang and Junglyeok-tang has been prescribed for cough, chest pain, and many other similar cases. Cough and chest pain is shown in early lung cancer. That is why we used these prescriptions. Apoptosis happend on the human lung carcinoma A549 cells treated with Jeongiyeokdaejosapye-tang, Jeonglyeok-tang. The concentration-dependent inhibition of cell viability was observed and apoptosis was confirmed by DNA fragmentation. Bcl-2 and COX-2 mRNA expression decreased, but Bax mRNA expression increased, so it was identified with the case of indomethacin known to enhance apoptotic DNA fragmentation. Also expression of the p21, p53, cyclin E, cyclin D1, cytochrome c, caspase-3, and caspase-9 protein increased and the activity of caspase-3 increased, as well. Last, fragmentation of the PARP was shown. The previous and present results indicated that apoptosis of A549 cells by above-mentioned drugs is associated with the blockage of G1/S progression.

• Journal of Korean Society on Water Environment
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• v.30 no.5
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• pp.539-548
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• 2014

This study was carried out to investigate algal community structures and their correlations with environmental factors on five weir areas in the Nakdong River, South Korea. Water qualities, hydrodynamics, meteorological conditions and algal species compositions were observed in studied sites from May 2010 to Dec. 2013. Results showed that average total phosphorus concentration of 2013 was decreased by 52.4% in comparing with that from 2010 to 2011. Chlorophyll.a concentrations were positive significant with water temperature, pH, total phosphorus and total nitrogen, but is not significant with turbidity and suspended solids. Seasonal successions of algae were observed that Stephanodiscus sp. was dominant species with 65.3% of dominant frequency in studied site. Large algal biomass of the low temperature-adapted diatoms were observed during temperature range of $4{\sim}9^{\circ}C$, but large cyanobacterial biomass mainly during high temperature period ranged from $22^{\circ}C$ to $32^{\circ}C$. Microcystis sp. dominated during high water temperature in summer. The yearly correlations of algal biomass with accumulated solar radiations were not significant but seasonal correlations of summer from June to August were significant with correlation coefficient 0.33 (p<0.05). There were not significant correlations between turbidities and algal biomass. Turbidity and suspended solids concentrations were not significant correlation with algal biomass. According to the results, algal communities had strong correlation with water temperature and had partially correlation with solar radiation. For an effective management of algal blooms, water managers should survey with more long-term monitoring of various environmental factors and algal communities.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.5
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• pp.661-678
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• 2006

Products developed in this research is a software which can transfer the type of shape(.shp) into the type of ascii using the land cover data and the topography data in the metropolitan area of Seoul. In addition, it can calculate the $CO_2$ flux according to distribution of plants within the land cover data. The $CO_2$ flux is calculated by the experimental equation which is compose of the meteorological parameters such as the solar radiation and the air temperature. The net flux was shown in about $-19ton/km^2$ by removing $CO_2$ through the photosynthesis during daytime, and in 2 ton/km2 by producing it through the respiration during nighttime on 10 August 2004, the maximum day of air temperature during the period of 3yr(2001 to 2004), in the metropolitan area of Seoul. Spatial distribution of the air temperature and the wind field is simulated by substituting the middle classification of the land cover map data, upgraded by the Korean Ministry of Environment(KME), for the land-use data of the United States Geological Survey(USGS) within the Meteorological Mesoscale Model Version 5(MM5) on 10 August 2006 in the metropolitan area of Seoul. Difference of the air temperature between both data was shown in the maximum range of $-2^{\circ}C\;to\;2.9^{\circ}C$, and the air temperature due to the land use data of KME was higher than that of USGS in average $0.4^{\circ}C$. Also, those of wind vectors were meanly lower than that of USGS in daytime and nighttime. Furthermore, the hourly time series of Volatile Organic Components(VOCs) is calculated by using the Biosphere Emission and Interaction System Version 2(BEIS2) including the new land cover data and the meteorological parameters such as the air temperature and so]ar insolation. It is possible to calculate the concentration of ozone due to the biogenic emission of VOCs.

• Journal of Korea Water Resources Association
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• v.50 no.12
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• pp.837-847
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• 2017

Land Surface Model (LSM) was developed for the Soyang river basin located in Korean Peninsula to clarify the spatio-temporal variability of hydrological weather parameters. Variable Infiltration Capacity (VIC) model was used as a LSM. The spatial resolution of the model was 10 km and the time resolution was 1 day. Based on the daily flow data from 2007 to 2010, the 7 parameters of the model were calibrated using the Isolated Particle Swarm Optimization algorithm and the model was verified using the daily flow data from 2011 to 2014. The model showed a Nash-Sutcliffe Coefficient of 0.90 and a correlation coefficient of 0.95 for both calibration and validation periods. The hydrometeorological variables estimated for the Soyang river basin reflected well the seasonal characteristics of summer rainfall concentration, the change of short and shortwave radiation due to temperature change, the change of surface temperature, the evaporation and vegetation increase in the cover layer, and the corresponding change in total evapotranspiration. The model soil moisture data was compared with in-situ soil moisture data. The slope of the trend line relating the two data was 1.087 and correlation coefficient was 0.723 for the Spring, Summer and Fall season. The result of this study suggests that the LSM can be used as a powerful tool in developing precise and efficient water resources plans by providing accurate understanding on the spatio-temporal variation of hydrometeorological variables.

• Journal of the Korean Applied Science and Technology
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• v.27 no.4
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• pp.559-567
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• 2010

In this study, the antioxidative effect, cellular protective effect and inhibitory effect on tyrosinase of Cosmos bipinnatus extracts were investigated. The ethyl acetate fraction of Cosmos bipinnatus flower extract ($11.48\;{\mu}g$/mL) showed more excellent free radical (1,1-diphenyl-2-picrylhydrazyl radical, DPPH) scavenging activity (FSC50) than those of leaf and stem extracts ($17.45\;{\mu}g$/mL). Reactive oxygen species (ROS) scavenging activity (OSC50) of Cosmos bipinnatus extracts on ROS generated in $Fe^{3+}$-EDTA/H2O2 system were investigated using the luminol-dependent chemiluminescence assay. The ethyl acetate fraction of Cosmos bipinnatus flower extract ($0.56\;{\mu}g$/mL) showed 3 times more excellent ROS scavenging activity than L-ascorbic acid ($1.50\;{\mu}g$/mL). The protective effects of the ethyl acetate fractions of extracts from different parts of Cosmos bipinnatus on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The ethyl acetate fractions of leaf and stem extract and flower extracts suppressed photohemolysis in a concentration dependent manner ($10\sim50\;{\mu}g$/mL). The inhibitory effect of ethyl acetate fraction of Cosmos bipinnatus flower extract ($62.75\;{\mu}g$/mL) on tyrosinase was investigated to assess the whitening efficacy. The ethyl acetate fraction of Cosmos bipinnatus flower extract showed 3.5 times higher tyrosinase inhibitory effect than arbutin ($226.88\;{\mu}g$/mL) known as an effective whitening agent. These results indicate that fractions of Cosmos bipinnatus extracts can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging $^1O2$ and other ROS, and protect cellular membranes against ROS. Fractions of Cosmos bipinnatus extracts can be applicable to new functional cosmetics for antioxidant and whitening.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.2
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• pp.61-67
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• 2007

In this study, the antioxidative effects of Equisetum arvense extracts were investigated. The free radical (1,1 diphenyl-2-picrylhydrazyl, DPPH) scavenging activity ($FSC_{50}$) of extract/fractions of Equisetum arvense was in the order: 50 % ethanol extract ($182.04{\mu}g/mL$) < ethylacetate fraction ($54.50{\mu}g/mL$) < deglycosylated flavonoid aglycone fraction ($14.13{\mu}g/mL$). Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of some Equisetum arvense 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 activity was deglycosylated flavonoid aglycone fraction ($OSC_{50}$, $3.54{\mu}g/mL$) < 50 % ethanol extract ($0.80{\mu}g/mL$) < ethylacetate fraction ($0.006{\mu}g/mL$). Ethylacetate fraction showed the most prominent scavenging activity. The protective effects of extract/fractions of Equisetum arvense on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The ethanol extract (50%) suppressed photohemolysis in a concentration dependent manner, particularly deglycosylated aglycone extract exhibited the most prominent celluar protective effect ($\tau_{50}$, 161.10 min at $10{\mu}g/mL$). These results indicate that extract/fractions of Equisetum arvense 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.

• Carbon letters
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• v.23
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• pp.38-47
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• 2017

In this study, magnetite ($Fe_3O_4$) nanoparticles were electrochemically synthesized in an aqueous electrolyte at a given potential of -1.3 V for 180 s. Scanning electron microscopy revealed that dendrite-like $Fe_3O_4$ nanoparticles with a mean size of < 80 nm were electrodeposited on a glassy carbon electrode (GCE). The $Fe_3O_4/GCE$ was utilized for sensing chloramphenicol (CAP) by cyclic voltammetry and square wave voltammetry. A reduction peak of CAP at the $Fe_3O_4/GCE$ was observed at 0.62 V, whereas the uncoated GCE exhibited a very small response compared to that of the $Fe_3O_4/GCE$. The electrocatalytic ability of $Fe_3O_4$ was mainly attributed to the formation of Fe(VI) during the anodic scan, and its reduction to Fe(III) on the cathodic scan facilitated the sensing of CAP. The effects of pH and scan rate were measured to determine the optimum conditions at which the $Fe_3O_4/GCE$ exhibited the highest sensitivity with a lower detection limit. The reduction current for CAP was proportional to its concentration under optimized conditions in a range of $0.09-47{\mu}M$ with a correlation coefficient of 0.9919 and a limit of detection of $0.09{\mu}M$ (S/N=3). Moreover, the fabricated sensor exhibited anti-interference ability towards 4-nitrophenol, thiamphenicol, and 4-nitrobenzamide. The developed electrochemical sensor is a cost effective, reliable, and straightforward approach for the electrochemical determination of CAP in real time applications.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.3 s.47
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• pp.295-305
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• 2004

Colloid and surface chemistry have been focused on surface area and surface energy. Local surface properties such as surface density, interaction, molecular orientation and reactivity have been one of interesting subjects. Systems of such surface energy being important would be listed as association colloid, emulsion, particle dispersion, foam, and 2-D surface and film. Such nanoparticle systems would be applied to drug delivery systems and functional cosmetics with biocompatible and degradable materials, while nanoparticles having its size of several nm to micron, and wide surface area, have been accepted as a possible drug carrier because their preparation, characteristics and drug loading have been inves-tigated. The biocompatible carriers were also used for the solubilization of insoluble drugs, the enhancement of skin absorption, the block out of UV radiation, the chemical stabilization and controlled release. Nano/micro emulstion system is classified into nano/microsphere, nano/microcapsule, nano/microemulsion, polymeric micelle, liposome according to its prep-aration method and size. Specially, the preparation method and industrial applications have been introduced for polymeric micelles self-assembled in aqueous solution, nano/microapsules controlling the concentration and activity of high concen-tration and activity materials, and monolayer or multilayer liposomes carrying bioactive ingredients.