• Journal of radiological science and technology
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• v.35 no.4
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• pp.299-308
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• 2012

To perform patient dose surveys in major interventional radiography procedures as a mean of inter-institutional comparison and of establishing reference dose levels with the ultimate goal of optimizing patient doses in the field of interventional radiography. We reviewed international patient dose survey data in the literature and measured patient dose in major interventional radiography procedures (TACE, AVF, PTBD, TFCA, GDC embolization). ESD(Entrance Skin Dose) was measured using TLD chips attached to the patient skin and ED(Effective Dose) was calculated using angiography unit-derived DAP. A survey of patient dose in interventional radiography procedures were also performed with a questionnaire for interventional radiologists and we proposed a guideline for optimizing patient doses in the field of interventional radiology. The patient dose survey data in interventional radiography procedures were very rare in literature compared with those in diagnostic radiography procedures. In TACE, the mean ED was 25.43 mSv and the mean ESD was 511.75 mGy. The mean ED of TACE was not high, but the cumulative dose should be checked, due to longer procedure TACE. In TFCA, the mean ED was 22.6 mSv and it was relatively high compared with data of other countries. In GDC embolization, the mean ED was not available, because GDC embolization was performed with old Image-Intensifier-type unit and there has no unit-installed ionization chamber. Also, the mean ESD of GDC embolization was up to 2,264 mGy and further studies are needed to calculate the net ED of GDC embolization. Patient dose occurred during interventional radiography procedures are high related with the difficulty of the procedure, fluoroscopy time, the number of angiographies and the treatment protocol. Therefore, continuous education and efforts should be made to optimize the patient dose in the field of interventional radiology.

• Journal of radiological science and technology
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• v.30 no.3
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• pp.213-219
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• 2007

The purpose of this study is to evaluate shielding effect of radiation protector for interventional radiologists in procedures by measuring inside and outside of radiation protector. In this study, we measured the radiation dose of 4 interventional radiologists during TACE and PTBD procedure for 4 month(2005.05-2005.09). Absorbed dose were measured by TLD placed underneath and over radiation protector such as Goggle, Thyroid protector, Apron and placed on the 4th finger of Hand. In addition, we measured background radiation dose in the control room using TLD. During TACE procedure, using 0.07 mmPb Goggle decreased average 53.8% of radiation dose rate in continuous fluoroscopic mode and decreased average 77.6% of radiation dose rate in pulse fluoroscopic mode. Using 0.5 mmPb Thyroid protector decreased average 88.9% of radiation dose rate in continuous fluoroscopic mode and decreased average 92.8% in pulse fluoroscopic mode. During PTBD procedure, using 0.07 mmPb Goggle decreased radiation dose rate average 62.7%, 87.9% by 0.5 mmPb Thyroid protector, 90.5% by 0.5 mmPb Apron. The average fluoroscopic time of PTBD was 6.14 min. shorter than TACE procedure, but radiation exposure dose rate of PTBD was 3 times higher in total body dose, and 40 times higher in hand dose rate than TACE. Interventional radiologists must wear thicker protector recommended over 0.5 mmPb. Also, they must use lead Goggle during interventional procedure. Abdomen dose decreased average 38.4% by drawing a lead curtain under the patient's table, therefore, they must draw a lead curtain to shield scattering ray. Radiation exposure dose decreased average 59.0% by using pulse fluoroscopic mode. So radiologists would better use pulse fluoroscopic mode than continuous fluoroscopic mode to decrease exposure dose.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.739-744
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• 2020

This study evaluates the erosive potential and effects of mixed alcohols by analyzing the pH, titratable acidity, and fluorescence loss degree (△F). Following alcohol groups were investigated: Soju, Calamansi+soju, Yakult+soju, Cola+soju, and Energy drink+soju. The ratio of soju:beverage in the alcohol mixtures was 7:3. Ed. Notes: The sentence lacks clarity. Please review if the edit correctly portrays the meaning. If not, please revise appropriately. Measurement of the pH and titratable acidity (the amount of 1M NaoH solution required to raise to pH 5.5 (TA5.5) and 7.0 (TA7.0)) of alcohols was achieved by stirring with pH meter. The erosive effect of the alcohol mixtures on bovine tooth (△F) after 1, 2, 4, and 6 hours exposure were analyzed by quantitative light-induced fluorescence (QLF-D). All the mixed alcohols in this study showed an acidic pH, lower than 4.5. The average pH of mixed alcohols was 3.17 ± 0.50 whereas the pH of Soju was 8.6 ± 0.01. The TA5.5 and TA7.0 values of the mixed alcohols were 0.5~18 and 0.5~23.5, respectively. △F of the three tested mixed alcohol groups (except yakult+soju group) were observed to increase in a time-dependent manner. The calamansi mixed alcohol had the highest acidity potential and erosive effect among the tested groups. Taken together, the results indicate that the mixed alcohols have a strong erosive effect and potential on dental enamel.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.477-484
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• 2019

Several types of scavenger receptors, including the Collectin-Placenta 1 (CL-P1) receptorthat is present in mammals, are molecules that are expressed on the surfaces of endothelial cells, macrophages and smooth muscle cells. These molecules are cell surface glycoproteins that can be conjugated to oxidized low density lipoprotein (oxLDL). Among these molecules, the effect of quercetin on CL-P1 activation has been confirmed. Quercetin is known as an antioxidant that stops oxidation because it acts to remove free radicals that are responsible for the oxidation reaction. In this study, fragments from the transcription start site of the mouse CL-P1 gene promoter to the -500th base were cloned using DNA polymerase. These fragments were then introduced into macrophage like RAW264.7 cells and fibroblast-like NIH3T3 cells to study the effect of quercetin on the CL-P1 gene expression. As a result, we found that bases ranging from -250 to -350 in the anterior part where gene expression starts are important for producing CL-P1 protein. Among them, the DNA mutation experiments we performed confirmed that the E2F binding sites are critical for producing the CL-P1 protein? In addition, when quercetin was added to the RAW264.7 culture medium, which was a culture of adherent cells, observedthe phenomenon of the cells falling off from the surface of the culture container.

• Journal of the Korean Applied Science and Technology
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• v.39 no.5
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• pp.644-651
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• 2022

The skin is the largest organ of the human body and protects the inside of the body. Ultraviolet rays cause various inflammatory reactions in the skin, including photoaging and oxidative damage. The purpose of this study is to investigate the protective effect of Saponaria extract by irradiating UVB on fibroblasts. In this study, the effectiveness of Saponaria showing protective activity against UVB-induced cytotoxicity, oxidative cell death, and NO and PGE₂ production was evaluated. HS68 cells were irradiated with UVB(120 mJ/cm²) and treated with Saponaria extract at various concentrations of 100, 200, and 400 ㎍/mL for 24 hours. Intracellular reactive oxygen species (ROS) generated by ultraviolet B were detected using a spectrofluorometer after DCF-DA staining. Lipid peroxidation was also analyzed by measuring the level of 8-isoprostane secreted into the culture medium. As a result, treatment with Saponaria extract effectively inhibited UVB-induced cytotoxicity. Oxidative cell damage was mediated by PGE₂ in UVB-induced HS68 fibroblasts, which was significantly inhibited by Saponaria extract treatment. In addition, it was evaluated that the protective effect of these extracts was mediated by the inhibition of intracellular ROS production and lipid peroxidation in a concentration-dependent manner. These results suggest that Saponaria extract can be used as an anti-aging functional material because it inhibits skin damage mediated by oxidative stress caused by UVB and exhibits a cellular protective effect.

• Journal of the Korean Applied Science and Technology
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• v.40 no.4
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• pp.856-867
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• 2023

Due to the increase in fine dust caused by environmental pollution, oxidative damage and aging of the skin are accelerated. In this study, the antioxidant, hyaluronic acid, filaggrin, MMP-1, and ROS level of selected herbal extracts were evaluated to confirm the protective efficacy of keratinocytes treated PM10. As a result, the antioxidant capacity of 1,1-diphenyl-2-picrylhydrazyl(DPPH), 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid(ABTS), and FRAP assay increased in a concentration-dependent manner. Keratinocytes the group treated with 300 ㎍/ml of PM10, hyaluronic acid and filaggrin decreased by more than 50%, and increased in the group treated with extracts of Alpinia officinarum, Ulmus macrocarpa, and Ulmus macrocarpa but decreased when the extract was treated, which is evaluated as inhibiting the degradation of collagen and elastin. In addition, in the case of ROS measurement using zebrafish embryos, it was confirmed that the extract was reduced when the extract was treated 25 ㎍/ml, the intensity of fluorescence similar to the negative control was shown, confirming that the production of ROS was significantly reduced. Through this study, the selected oriental medicinal materials, Alpinia officinarum, Ulmus macrocarpa, and Ulmus macrocarpa, protect the skin from fine dust. It is thought that it can be used as an anti-aging product for skin improvement as a material that can be improved or improved.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.1
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• pp.1-17
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• 2019

In this study, the surveys were carried out from October (2016) to October (2017) along the tidal flat of Geunso Bay, Taean Peninsula of the western edge of Korea. The sampling trips were carried out for a total of 16 times, once or twice a month. In order to investigate the monthly variation of the microphytobenthos (MPB) biomass, community composition and photo-physiology were analyzed by HPLC (High performance liquid chromatography). The total chlorophyll a (TChl a) concentrations used as an indicator of biomass of MPB in the upper 1 cm sediment layer ranged from 40.4 to $218.9mg\;m^{-2}$ throughout the sampling period. TChl a concentrations showed the maximum level on $24^{th}$ of February and remained high throughout March after which it started to declined. The biomass of MPB showed high values in winter and low values in summer. The monthly variations of Phaeophorbide a concentrations suggested that the low grazing intensity of the predator in the winter may have partly attributed to the MPB winter blooming. As a result of monthly variations of the MPB community composition using the major marker pigments, the concentrations of fucoxanthin, the marker pigment of benthic diatoms, were the highest throughout the year. The concentrations of most of the marker pigments except for chlorophyll b (chlorophytes) and peridinin (dinoflagellates) increased in winter. However, the concentrations of fucoxanthin increased the highest, and the relative ratios of the major marker pigments to TChl a except fucoxanthin decreased during the same period. The vertical distribution of Chl a and oxygen concentrations in the sediments using a fluorometer and an oxygen micro-optode Chl a concentrations decreased with oxygen concentrations with increasing depth of the sediment layers. Moreover, this tendency became more apparent in winter. The Chl a was uniformly vertical down to 12 mm from May to July, but the oxygen concentration distribution in May decreased sharply below 1 mm. The increase in phaeophorbide a concentration observed at this time is likely to be caused by increased oxygen consumption of zoobenthic grazing activities. This could be presumed that MPB cells are transported downward by bioturbation of zoobenthos. The relative ratios (DT/(DD+DT)) obtained with diadinoxanthin (DD) and diatoxanthin (DT), which are often used as indicators of photo-adaptation of MPB, decreased from October to March and increased in May. This indicated that there were monthly differences in activity of Xanthophyll cycle as well.

• Progress in Medical Physics
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• v.26 no.3
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• pp.160-167
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• 2015

Radiation exposure from medical diagnostic imaging procedures to patients is one of the most significant interests in diagnostic x-ray system. A miniature x-ray intraoral tube was developed for the first time in the world which can be inserted into the mouth for imaging. Dose evaluation should be carried out in order to utilize such an imaging device for clinical use. In this study, dose evaluation of the new x-ray unit was performed by 1) using a custom made in vivo Pig phantom, 2) determining exposure condition for the clinical use, and 3) measuring patient dose of the new system. On the basis of DRLs (Diagnostic Reference Level) recommended by KDFA (Korea Food & Drug Administration), the ESD (Entrance Skin Dose) and DAP (Dose Area Product) measurements for the new x-ray imaging device were designed and measured. The maximum voltage and current of the x-ray tubes used in this study were 55 kVp, and 300 mA. The active area of the detector was $72{\times}72mm$ with pixel size of $48{\mu}m$. To obtain the operating condition of the new system, pig jaw phantom images showing major tooth-associated tissues, such as clown, pulp cavity were acquired at 1 frame/sec. Changing the beam currents 20 to $80{\mu}A$, x-ray images of 50 frames were obtained for one beam current with optimum x-ray exposure setting. Pig jaw phantom images were acquired from two commercial x-ray imaging units and compared to the new x-ray device: CS 2100, Carestream Dental LLC and EXARO, HIOSSEN, Inc. Their exposure conditions were 60 kV, 7 mA, and 60 kV, 2 mA, respectively. Comparing the new x-ray device and conventional x-ray imaging units, images of the new x-ray device around teeth and their neighboring tissues turn out to be better in spite of its small x-ray field size. ESD of the new x-ray device was measured 1.369 mGy on the beam condition for the best image quality, 0.051 mAs, which is much less than DRLs recommended by IAEA (International Atomic Energy Agency) and KDFA, both. Its dose distribution in the x-ray field size was observed to be uniform with standard deviation of 5~10 %. DAP of the new x-ray device was $82.4mGy*cm^2$ less than DRL established by KDFA even though its x-ray field size was small. This study shows that the new x-ray imaging device offers better in image quality and lower radiation dose compared to the conventional intraoral units. In additions, methods and know-how for studies in x-ray features could be accumulated from this work.

• Journal of Bio-Environment Control
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• v.31 no.1
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• pp.67-76
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• 2022

This study aimed to determine the photosynthesis and growth characteristics of Peucedanum japonicum T. grown under aquaponics in a plant factory (AP) by comparing those grown under hydroponic cultivation system (HP). The AP system raised 30 fishes at a density of 10.6 kg·m^-3 in a 367.5 L tank, and at HP, nutrient solution was controlled with EC 1.3 dS·m^-1 and pH 6.5. The pH level ranged from 4.0 to 7.1 for the AP system and 4.0 to 7.4 for the HP system. The pH level in the AP began to decrease with an increase in nitrate nitrogen (NO₃-N) and lasted bellower than pH 5.5 for 15-67 DAT. It was found that ammonium nitrogen (NH₄-N) continued to increase even under low pH conditions. EC was maintained at 1.3 to 1.5 dS·m^-1 in both systems. The concentration of major mineral elements in the fish tank was higher than that of the hydroponics, except for K and Mg. There was no significant difference in the photosynthesis characteristics, but the PIABS parameters were 30.4% lower in the AP compared to the HP at the 34DAT and 12.0% lower at the 74DAT. There was no significant difference in the growth characteristics, but the petiole length was 56% longer in the leaf grown under the AP system. While there was no significant difference in the fresh and dry weights of leaf and root, the leaf area ratio was 36.43% higher in the AP system. All the integrated results suggest that aquaponics is a highly-sustainable farming to safely produce food by recycling agricultural by-products, and to produce Peucedanum japonicum as much as hydroponics under a proper fish density and pH level.

• Journal of Conservation Science
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• v.30 no.3
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• pp.249-261
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• 2014

This study aims to examine production technique of white wares from the Guyre-2ri 1st and 2nd kiln sites, Wonju, Gangwon Province and characteristics of the used materials, and to find a correlation among materials of the excavated white wares. X-ray fluorescence sequential spectroscopy(XRF), X-ray diffraction(XRD), Dilatometer and Inductively coupled plasma mass spectrometry(ICP-MS), Inductively coupled plasma automic emission spectrometer(ICP-AES) were applied to determine the chemical composition, crystalline phase of samples, firing temperatures, trace elements and rare earth elements. White wares from the Guyre-2ri kiln sites contained high contents of coloring oxides and fluxes. Though firing temperature of each sample was different, they were mostly fired at a temperature below $1200^{\circ}C$ and some of them experienced a low temperature of $1000^{\circ}C{\pm}20^{\circ}C$ and a high temperature above $1200^{\circ}C$. When analyzing body crystalline phases of the white wares using the XRD method, quartz and mullite were extracted from all the samples, and the proportions were similar to each other. When analyzing the excavated white wares using the Seger formula, also, all the samples showed similar clay sources and production techniques. Moreover, the white wares were made of host rocks of the same geological origin, according to the result of rare earth elements analysis.