• Korean Journal of Environment and Ecology
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• v.34 no.5
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• pp.491-499
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• 2020

Increasing impervious surfaces can cause various physical and mental illnesses as well as further problems like deterioration of the thermal environment and disconnection of the water circulation system in the downtown area. This study is intended to suggest baseline data for the future creation or remodelation of large-scaled urban parks in consideration of human health on the aspect of climate by analyzing air ions condition and correlation analysis between air ions and meteorological elements depending on distances from the center in the urban park. The study site was divided into four types by distances from the center of Olympic Park in Songpa-gu, Seoul, then classified as A and B. After selecting 80 points to record, land coverage and vegetation status were investigated, and then meteorological elements and air ions were measured. First, the green space rate by section is A section Center (90%)> Inner (70%)> Outer-inner (10%) = Outer (10%), B section Center (100%)> Inner (60%)> Outer- In order of inner (30%)> Outer (0%). Second, for weather factors, the temperature was analyzed by Outer (24.18℃) > Outer-inner (22.90℃) > Inner (22.43℃) > Center (21.719℃). For relative humidity, center (46.49%) > Inner (43.36%) > Outer-inner (42.41%) > Outer (38.53%) was analyzed. Third, In the case of cations in the air ions, Outer(435.71ea/㎤) > Outer-inner(415.16ea/㎤) > Inner (389.46ea/㎤) > Center (352.64ea/㎤). In the case of negative ions, Center (569.72ea/㎤) > Inner (499.83ea/㎤) > Outer-inner(410.58ea/㎤) > Outer (292.02ea/㎤). It was analyzed to increase toward Center, and analyzed to decrease with increasing distance from road. For the Air ion index, it was analyzed as Center (1.67) > Inner (1.31) > Outer-inner (1.08) > Outer (0.71). Negative irons was analyzed to increase when its measuring points close to the center and decrease with shortening distance to the road. Fourth, as a result of correlation analysis, positive(+) correlation is negative ions and ion index. These were measured to increase as the recording points closing to the center of the park from the road. The negative(-) correlation is temperature, solar radiation, and positive ions. These increased as getting closer to the road.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.1
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• pp.44-49
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• 2012

Purpose: In the whole body PET/CT scan, it is natural to lift the patient's arm for its quality improvement. However, when the lesion is located in head and neck, the arms should be located lower. This study was designed to compare the CT effective dose for each arm position applying Automatic Exposure Control (AEC). Materials and Methods: 45 patients who had $^{18}F$-FDG whole body PET/CT scan were studied with Biograph Truepoint 40 (SIEMENS, GERMANY), Biograph Sensation 16 (SIEMENS, GERMANY), Discovery STe 8 (GE healthcare, USA). The CT effective dose of 15 patients for each equipment was measured and comparatively analyzed in both arm-lifted position and lower-arm position. ImPACT v1.0 program was used as the method of measurement for CT effective dose. For the statistics analysis, Paired t-test which paired with SPSS 18.0 statistic program was applied. Results: In the case of arm-lifted, it was measured as $6.33{\pm}0.93mSv$ for Biograph Sensation 16, $8.01{\pm}1.34mSv$ for Biograph Truepoint 40, and $9.69{\pm}2.32mSv$ for Discovery STe 8. When arms are located lower position, it was measure as $6.97{\pm}0.76mSv$, $8.95{\pm}1.85mSv$, $13.07{\pm}2.87mSv$ for each. CT effective dose according to the arm position was 9.2% for Biograph Truepoint 40, 10.5% for Biograph Sensation 16, and 25.9% for Discovery Ste 8. The statistics analysis showed the meaningful difference ($p$<0.05). Conclusion: For the whole body PET/CT case, CT effective dose applying AEC was decreased the radiation exposure of the patients when the arm was lifted for 15.2% of average value. The patient who has no lesion in head and neck would decrease the artifact occurrence in objective part and lower the CT effective dose. Also, for the patient who had lesion in head and neck, the artifact in objective part can be lower by putting the arms down, the fact that CT effective dose increases should be concerned in its whole body PET/CT scan.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.2
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• pp.3-7
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• 2014

Purpose SPECT/CT scan to be performed attenuation correction on the basis of CT induce an overestimation of the site due to the beam hardening artifact by metal cover and reduce the images quality. Therefore, this study using a phantom that has been inserted artificial hip joint investigated that effect on the SPECT/CT image causing by metal artifact for varying the parameters of the Attenuation Map. Materials and Methods Siemens Symbia T16 SPECT/CT equipment was used. Artificial hip joint was inserted to SPECT/PET phantom, 17 mm sphere of Bright Streak area in CT image was filled with Tc-99m so that the radiation activity was 8 times compared to background. And then Hot and Background was measured in varying Wide Beam Coefficient on Attenuation Map and RBR (Region to Background Ratio) of Metal and Non-Metal was calculated and analyzed depending on the presence or absence of the hip joint. Results It tended to hot count of Non-Metal and Metal to increase as the value of the manual mode is increased, hot count ratio with the group of both manual mode 0.5 and 0.4 is the best match. Also, in automatic mode, the ratio of RBRNon-Metal and RBRMetal was 1.135, statistically significant difference was not observed in the manual mode 0.5 and 0.4. Conclusion In the automatic mode of Wide Beam Coefficient in attenuation correction map, it was found that it is over-correction by 13.52%, it was possible to minimize the over-correction by the artifact in 0.5 and 0.4 of manual mode. Further studies should be performed in order to apply to a patient with the help of this and it is considered possible to reduce the over-correction by the metal artifact of an artificial hip joint for Hip-Resurfacing Arthroplasty patients, and to improve the diagnostic performance.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.177-180
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• 2010

Purpose: As PET test came to be covered by the pay system of medical insurance (July 1, 2006) and the needs for it becoming increased for laboratory purpose, it became necessary to purchase expensive medical equipments to solve those problems. However, as most of equipments that are operated by cyclotron are very expensive as to amount from tens of millions up to hundreds of millions of won, it is difficult to purchase those equipments from the point of medical organizations. It may be possible to self manufacture those equipments with least costs if their parts functions that meets the operators demands. The Nuclear Medicine department of National Cancer Center (NCC) is trying to manufacture and use equipments that can be made with least costs, including introducing 2 medical equipments that can improves the operator's works. Materials and Methods: Example 1: Self production of radioisotope($^{18}F$) divider was fabricated. The NCC's Nuclear Medicine department acquired one acrylic panel, seven 3-way valve, tubing etc. that can be found in the market to make the main body of divider in cooperation with biomedical engineering, and placed them inside hot cell, and installed switching box outside of hot cell to make it possible to control them from outside. This main body of divider were placed in radioisotope transfer line that are manufactured in the cyclotron. Example 2: Self production of $^{18}F$-FDG automated divider was fabricated. The NCC's Nuclear Medicine department used cavro pump syringe that consists the main body of divider in cooperation with biomedical engineering, biomedical engineering developed programs that divides a certain amount. $^{18}F$-FDG automated divider is placed inside hot cell, and cable chords were used in the equipment, and then it was connected to PC outside hot cell to make it possible to control the $^{18}F$-FDG automated divider. Results: From the NCC's Nuclear Medicine department tests that were carried out from March, 2007 until now, we found out that radioisotope can be sent to radiopharmaceuticals composite module we want, and from the tests that are carried out at NCC's Nuclear Medicine department using $^{18}F$-FDG automated divider since August, 2009 it was possible to distribute radiopharmaceuticals into vial intended. Conclusion: Through the two examples above, we found out that costs can be reduced by self manufacturing expensive equipments from NCC's cyclotron room with least costs. Also, it decreased radiation exposure dose on workers, and set up problem solving processes in cooperation with lots of parties related.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.3
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• pp.157-163
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• 2005

The increasing of greenhouse gases may change agricultural environment. The agronomic productivity will depend upon change of temperature, precipitation, solar radiation and fertilization. Particularly, nitrogen fertilization considerably influences rice productivity and agricultural environments. This experiment was conducted to study transformation of nitrogen and to determine the primary yield components responsible for yield differences in paddy soil. $NH_4-N$ concentration of NPK plot in surface water of paddy soil was $2.07mg\;L^{-1}$ at 5 days after transplanting, and then was decreased sharply due to rice absorption and loss to environment. $NO_3-N$ concentration of NPK plot in surface water was $3.97mg\;L^{-1}$ at 10 days after transplanting. $NO_3-N$ concentration range of CRF plot in surface water was $3-5mg\;L^{-1}$ at 30th after transplanting. The accumulation of $NH_3$ volatilization in NPK plot was $22.39kg\;ha^{-1}$, which accounted for 20% of N fertilizer applied but using of CRF fertilizer can reduce $NH_3$ volatilization by 67% in paddy soil. Use efficiency of N fertilizer was not different between CRF70% and CRF100% plot. Rate of N use efficiency were 27.4%, 51.2%, 49.0% in paddy field NPK, CRF70% and CRF100% plots respectively. The yield of CRF70% showed the best effect with 9.3% increase production ratio, compare with NPK plot.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.3
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• pp.150-156
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• 2005

The increasing emission of greenhouse gases may change agricultural environment. The agronomic productivity will depend upon change of temperature, precipitation, solar radiation and fertilization. This study was conducted to investigate greenhouse gas emission with irrigation water depth in paddy field. Area of each experiment plot is $70m^2$, Three treatments with three replications were carried out in this experiment, which was laid out as randomized complete block design. The treatments of irrigation water were maximum field water capacity and 4 and 8 cm depth. The application rate of fresh rice straw was $8,000kg\;ha^{-1}$ in combination with chemical fertilizers ($110kg\;N\;ha^{-1}$, $45kg\;P_2O_5\;ha^{-1}$ and $57kg\;K_2O\;ha^{-1}$). The $CH_4$ emission was highest at 32 days after rice transplanting with rice straw treatment. The $CH_4$ emission in the plot of maximum field water capacity was lower compared with 4 and 8 cm of irrigation depth. $CH_4$ and $N_2O$ emission under different water depth in the paddy field were 30 and $1.52kg\;ha^{-1}$ at 8 cm depth, 281 and $1.71kg\;ha^{-1}$ at 4 cm depth, and 219 and $2.01kg\;ha^{-1}$ at water saturated condition. The total emission of greenhouse gases equivalent to $CO_2$ emission with rice straw application were $6,939kg\;CO_2\;ha^{-1}$ at 8 cm depth plot, $6,431kg\;CO_2\;ha^{-1}$ at 4 cm depth plot and $5,222kg\;CO_2\;ha^{-1}$ at water saturated condition. The GWPs without rice straw application were $4,449kg\;CO_2\;ha^{-1}$ at 8 cm depth plot, $3,702kg\;CO_2\;ha^{-1}$ at 4 cm depth plot and $4,579kg\;CO_2\;ha^{-1}$ at water saturated condition.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.3
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• pp.31-42
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• 2009

Purpose: As the number of domestic medical institutions installing PET/CT is increasing rapidly, the transfer of PET/CT images among medical institutions is also increasing. Thus, it is necessary to collect the comparative SUV data from several medical institutions' PET/CT systems through a phantom study which semi-quantitatively compares the SUV on one bed, the change scale of the SUV on the slices, and the time of measuring. The phantom study to find differences among the SUVs from various PET/CT offers the opportunity to obtain the reliability of the SUV in PET/CT images. Materials and Methods: Ten PET/CT systems from medical institutions in Korea were used. To obtain the accurate data, the study has been using the radiation detector of Korea Research Institute of Standards and Science to verify. The internal structures of NEMA $phantom^{TM}$ were removed and Six thousand milliliters of distilled water which has 1mCi of $^{18}F$-FDG put into the phantom. The water was properly integrated with $^{18}F$-FDG using magnetic stirrer. The images were acquired at 60, 70, 80, 90, 100, 110 and 120-minutes for 3 minute each. Two hundred square centimeters of region of interests were placed and analyzed. To confirm the usefulness, the correction-table came out from patients' data. Results: The coefficient of variability of the SUV from -11.0 to 9.90 % fell into the range of international standards(${\pm}10%$) along with the SUV on a bed, the change scale of the SUV on the slices, and the time of measuring, except one PET/CT system. Using the data of the differences among the SUVs, we came to withdraw the correction-table ranging from 0.803 to 1.246. The correction-table was confirmed its usefulness through Linear Regression Analysis which was applied to normal cases. Conclusions: Although studies have been made on the variation of the SUV, there is little attention on the standardization of the SUV. Based on this study of the quantitatively comparable data about the SUV accommodating the correction-table, it would help to have more corrective diagnosis.

• Journal of radiological science and technology
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• v.36 no.4
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• pp.291-297
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• 2013

This study is aimed to evaluate the effect of $T_{1/2}$ upon count rates in the analysis of dynamic scan using NaI (Tl) scintillation camera, and suggest a new quality control method with this effects. We producted a point source with $^{99m}TcO_4^-$ of 18.5 to 185 MBq in the 2 mL syringes, and acquired 30 frames of dynamic images with 10 to 60 seconds each using Infinia gamma camera (GE, USA). In the second experiment, 90 frames of dynamic images were acquired from 74 MBq point source by 5 gamma cameras (Infinia 2, Forte 2, Argus 1). There were not significant differences in average count rates of the sources with 18.5 to 92.5 MBq in the analysis of 10 to 60 seconds/frame with 10 seconds interval in the first experiment (p>0.05). But there were significantly low average count rates with the sources over 111 MBq activity at 60 seconds/frame (p<0.01). According to the second analysis results of linear regression by count rates of 5 gamma cameras those were acquired during 90 minutes, counting efficiency of fourth gamma camera was most low as 0.0064%, and gradient and coefficient of variation was high as 0.0042 and 0.229 each. We could not find abnormal fluctuation in $x^2$ test with count rates (p>0.02), and we could find the homogeneity of variance in Levene's F-test among the gamma cameras (p>0.05). At the correlation analysis, there was only correlation between counting efficiency and gradient as significant negative correlation (r=-0.90, p<0.05). Lastly, according to the results of calculation of $T_{1/2}$ error from change of gradient with -0.25% to +0.25%, if $T_{1/2}$ is relatively long, or gradient is high, the error increase relationally. When estimate the value of 4th camera which has highest gradient from the above mentioned result, we could not see $T_{1/2}$ error within 60 minutes at that value. In conclusion, it is necessary for the scintillation gamma camera in medical field to manage hard for the quality of radiation measurement. Especially, we found a tendency that count rate changes over time at this study, and we proved that it can effect $T_{1/2}$. And also, there is need of appropriate phantoms and the method of quality management like this study, because there are not any advice or limitation degrees for domestic medical purpose scintillation camera.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.1
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• pp.57-65
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• 2012

In the present study, the antioxidative properties, inhibitory activity on tyrosinase, and active components of Eriobotrya japonica (E. japonica) leaf extract were investigated. The free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity ($FSC_{50}$) of extract/fraction of E. japonica leaf was in the order 50 % ethanol extract ($22.625{\mu}g/mL$) < ethyl acetate fraction (6.75) < deglycosylated aglycone fraction (5.06). Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of fraction/extracton ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system using the luminol-dependent chemiluminescenceassay were investigated. $OSC_{50}$ of the ethyl acetate fraction, deglycosylated aglycone fraction, and ethanol extract were 0.75, 0.79, and $1.61{\mu}g/mL$, respectively. The cellular protective effects of E. japonica leaf extract on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The protective effects of extract/fraction of E. japonica leaf were increased in a in a concentration dependent manner ($5{\sim}50{\mu}g/mL$). Especially, ${\tau}50$ of ethyl acetate fraction at concentrations of $10{\mu}g/mL$ and $50{\mu}g/mL$ showed the most protective effects at 390.8 min and 1471.5 min. The inhibitory effect ($IC_50$) on tyrosinase of E. japonica leaf extracts was higher than arbutin, known as a skin-whitening agent. The order of inhibitory effects was acetate fraction ($75.25{\mu}g/mL$) < 50 % extract (74.1) < deglycosylated aglycone fraction (43.35). TLC of the ethyl acetate fraction showed 7 bands (EJL 1 - EJL 7). HPLC of the aglycone fraction exhibited 2 peaks, kaempferol and quercetin. The amounts of kaempferol and quercetin were 53.7 and 46.3 %. respectively. Therefore, The amounts of kaempferol and its glucoside were a little bit higher than quercetin and its glucoside in E. japonica leaf extract. Accordingly, these findings suggest that extracts/fractions of E. japonica leaf can function as antioxidants in biological systems, especially skin exposed to UV radiation, and protect cellular membranes against ROS. Thus, the extract/fraction of E. japonica leaf may be used in novel functional cosmetics as antioxidants against skin photoaging.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.4
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• pp.259-268
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• 2008

In this study, the antioxidative effects, inhibitory effects on tyrosinase and elastase and components of Castanea crenata leaf were investigated. The free radical (1,1-diphenyl-2-picrylhydrazyl radical, DPPH) scavenging activity ($FSC_{50}$) of extract / fractions of Castanea crenata left was in the order: 50% ethanol extract ($13.6{\mu}g/mL$) < ethyl acetate fraction (6.2) < aglycone fraction (2.1). Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$ of extract / fractions from Castanea crenata leaf extract / fractions 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 in the order: aglycone fraction (0.8) < 50% ethanol extract (0.5) < ethyl acetate fraction (0.3). The scavenging activity ($IC_{50}$ for ${O_2}^{{\cdot}\;-}$ (superoxide anion radical) generated by NBT method was in the order: ethyl acetate fraction (145.5) < aglycone fraction (65.5). The protective effects on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The ethyl acetate fraction exhibited the most prominent cellular protective effect (${\tau}_{50}$, $191.9{\pm}12.2\;min$ at $10{\mu}g/mL$). The inhibitory effect of aglycone fraction ($9.1{\mu}g/mL$) on elastase was higher than oleanolic and ($13.7{\mu}g/mL$). And the inhibitory effect of aglycone fraction ($21.6{\mu}g/mL$) on tyrosinase was higher than arbutin ($226.2{\mu}g/mL$). But 50% ethanol extract rarely exhibited the inhibitory activity on tryosinase and elastase. Flavonoids were contained in Castanea crenata left (96.3 mg / 100 g dried Castanea crenata leaf). And flavonoids contained in ethyl acetate fraction were kaempferol, quercetin, quercitrin, and so on. Quercitrin is the most abundant component. These results indicate that extract / fractions of Castanea crenata can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging free radical and ROS, Castanea crenata leaf extract/ fractions could be used as new cosmeceutical for whitening and anti-wrinkle products.