• Nutrition Research and Practice
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• v.18 no.5
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• pp.711-720
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• 2024

BACKGROUND/OBJECTIVES: The diet is an important route of exposure to endocrine-disrupting chemicals (EDCs). However, few studies have investigated the association between dietary intake and EDC exposure levels among Koreans. In an earlier study, we showed that the bioactivity of serum aryl hydrocarbon receptor ligands (AhRLs) could be a surrogate biomarker to indicate exposure to EDCs and that they inhibit mitochondrial function. We also found that the mitochondria-inhibiting substances (MIS) in serum ascertained by intracellular adenosine triphosphate (MIS-ATP) and reactive oxygen species (MIS-ROS) levels could be biomarkers of exposure to EDCs, as they showed a strong correlation with AhRL and the levels of EDCs in the blood. Here, we investigated the association between the consumption of specific foods and surrogate serum biomarkers for EDCs, namely AhRL, MIS-ATP, and MIS-ROS, among middle-aged Korean adults. SUBJECTS/METHODS: A total of 1,466 participants aged 45-76 yrs from the Ansung cohort of the Korean Genome and Epidemiology Study were included. Food consumption, including that of meat, fish, vegetables, and fruits, was measured using a semiquantitative food frequency questionnaire. RESULTS: Fish intake was positively associated with AhRL (β = 0.0035, P = 0.0166), whereas cruciferous vegetable intake was negatively associated with AhRL (β = -0.0007, P = 0.0488). Cruciferous vegetable intake was positively associated with the MIS-ATP levels (β = 0.0051, P = 0.0420). A higher intake of fish was significantly associated with an increased risk of high AhRL (tertile: odds ratio [OR], 1.49; 95% confidence intervals (CIs), 1.08-2.06; P for trend = 0.0305). In addition, the second-highest tertile of cruciferous vegetable intake had lower odds of high AhRL than the lowest tertile (OR, 0.73; 95% CIs, 0.54-0.97), although no significant linear trend was observed. CONCLUSION: Consumption of different types of foods may be differentially associated with EDC exposure in middle-aged Korean adults.

• Korean Journal of Materials Research
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• v.17 no.5
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• pp.268-272
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• 2007

Inconel 617 is a candidate tube material for high temperature gas-cooled reactors(HTGR). The microstructure and mechanical properties of Inconel 617 were studied after exposure at high temperature($1050^{\circ}C$). The dominant oxide layer was Cr-oxide. The internal oxide and Cr-depleted region were observed below the Cr-oxide layer. The depth of Cr-depleted zone and internal oxide increased with exposure time. The major phases of carbides are $M_{23}C_6\;and\;M_6C$. The composition of $M_{23}C_6\;and\;M_6C$ were determined to be Cr-rich and Mo-rich, respectively. $M_6C$ carbide is more stable than $M_{23}C_6$ at high temperature. From the results of high temperature compression test, there were no significant changes in hardness and yield strength upon increasing exposure time.

• Nuclear Engineering and Technology
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• v.53 no.1
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• pp.273-281
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• 2021

The radiological safety of the spent resin treatment facility with a¹⁴C treatment capacity of 1 ton/day was evaluated in terms of the external and internal exposure of worker according to operation scenario. In terms of external dose, the annual dose for close work for 1 h/day at a distance of more than 1 m (19.8 mSv) satisfied the annual dose limit. For 8 h of close work per day, the annual dose exceeded the dose limit. For remote work of 2000 h/year, the annual dose was 14.4 mSv. Lead shielding was considered to reduce exposure dose, and the highest annual dose during close work for 1 h/day corresponded to 6.75 mSv. For close work of 2000 h/year and lead thickness exceeding 1.5 cm, the highest value of annual dose was derived as 13.2 mSv. In terms of internal exposure, the initial year dose was estimated to be 1.14E+03 mSv when conservatively 100% of the nuclides were assumed to leak. The allowable outflow rate was derived as 7.77E-02% and 2.00E-01% for the average limit of 20 mSv and the maximum limit of 50 mSv, respectively, where the annual replacement of the worker was required for 50 mSv.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.75-80
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• 2011

Purpose: Europe and U.S use multi-bed therapy rooms. Hereupon, this study aims to examine the safety when current one-bed therapy rooms in Seoul National University Hospital is changed into two-bed ones. Materials and Methods: This study evaluated external exposure by gamma radiation emitted from other patients and internal and external exposure caused by pollutions from other patients in case that Seoul National University Hospital installs a shielding wall between beds in existing therapy rooms. Results: When internal and external exposure was evaluated to evaluate safety of two-bed hospital rooms, 'isolation amount of patients' 5mSv exposure or below is received according to the Atomic Energy Act. Conclusion: With the increasing number of patients with thyoid cancer, patients using therapy rooms are on the rise. Therefore, improving one-person therapy rooms to two-person ones in line with international trend would increase cost reduction and management efficiency, and patients' alienation and isolation can be reduced to increase healing effects.

• Journal of Radiation Protection and Research
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• v.34 no.2
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• pp.87-94
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• 2009

Tritium is the one of the dominant contributors to the internal radiation exposure of workers at pressurized heavy water reactors (PHWRs). This nuclide is likely to release to work places as tritiated water vapor (HTO) from a nuclear reactor and gets relatively easily into the body of workers by inhalation. Inhaled tritium usually reaches the equilibrium of concentration after approximately 2 hours inside the body and then is excreted from the body with a half-life of 10 days. Because tritium inside the body transports with body fluids, a whole body receives radiation exposure. Internal radiation exposure at PHWRs accounts for approximately 20-40% of total radiation exposure; most internal radiation exposure is attributed to tritium. Thus, tritium is an important nuclide to be necessarily monitored for the radiation management safety. In this paper, metabolism for tritium is established using its excretion rate results in urine samples of workers at PHWRs and an effective half-life, a key parameter to estimate the radiation exposure, was derived from these results. As a result, it was found that the effective half-life for workers at Korean nuclear power plants is shorter than that of International Commission on Radiological Protection guides, a half-life of 10 days.

• Journal of Radiation Protection and Research
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• v.26 no.3
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• pp.155-159
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• 2001

Beta radiation is measured for an environmental monitoring purpose or for an internal radiation exposure monitoring of nuclear power plant's worker. In korea, strontium 89 and strontium 90 is measured for an environmental monitoring purpose. Also tritium and carbon 14 contained in urine is measured for an internal radiation exposure monitoring of nuclear power plant's worker. Because above isotopes emits low energy beta radiations having a wide range of energy, very complicated isotope separation preprocess is needed. In this study, two mixed beta emitting isotopes are measured simultaneously using a liquid scintillation counter(LSC) and analyzed by using a developed statistical method. Banded least square method is used to analyze the mixed spectrum, and the goodness-of-fitness test is proposed. Test results show that the developed procedure can be very useful for analyzing a mixed beta emitting isotopes.

• The Journal of Internal Korean Medicine
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• v.41 no.4
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• pp.553-562
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• 2020

Objective: To investigate the vasodilatory effect of Sipjeondaebo-tang by inhibiting RhoA activity in vascular cells during cold exposure. Methods: Human vascular endothelial cells and pericytes were pretreated with Sipjeondaebo-tang for 30 min, followed by incubation at 37 ℃ (control) or 25 ℃ (cold exposure) for 30 min. Activation of endothelin-1-mediated RhoA in pericytes was assessed by pretreating the cells with Sipjeondaebo-tang for 30 min, followed by incubation with endothelin-1 at 37 ℃ for 30 min. Western blotting was performed to measure the expression of active RhoA. Endothelin-1 and nitric oxide release from endothelial cells was examined with enzyme-linked immunosorbent assay kits. The formation of stress fibers and focal adhesion complexes was analyzed by immunocytochemistry. Results: Cold treatment activated RhoA in both pericytes and vascular endothelial cells, whereas Sipjeondaebo-tang treatment inhibited this activation. Sipjeondaebo-tang treatment also reversed the cold-mediated production of endothelin-1 and nitric oxide. Cold exposure promoted the formation of stress fibers and focal adhesion complexes by increasing the expression of phospho-focal adhesion complex kinase, whereas Sipjeondaebo-tang treatment suppressed this response. Conclusions: These findings suggested that Sipjeondaebo-tang inhibits cold-induced RhoA activation and its related pathway components, including endothelin-1 and nitric oxide, in vascular cells. Therefore, Sipjeondaebo-tang could be beneficial for the treatment of Raynaud's phenomenon.

• Tuberculosis and Respiratory Diseases
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• v.40 no.1
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• pp.29-34
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• 1993

Background: The development of the flexible fiberoptic broncoscope by Ikeda was an important technologic advance in the diagnosis and management of patients with pulmonary disease. But, cross contamination related to fiberoptic bronchoscope was reported in cases involving tubercle bacilli, MOTT and other agents. Therefore, cleaning and disinfecting of fiberoptic bronchoscope requires careful attention. Methods: From September 1991 to May 1992, medical records of all patients with positive culture for MOTT in bronchial washing specimens were reviewed. Also to evaluate bactericidal effect of 2% glutaraldehyde, culture was performed after inoculum of MOTT, Serratia marsescens and Pseudomonas aeruginosa to the disinfectant solution. Results: In 2% alkaline glutaraldehyde, MOTT was not survived only after 30 minute exposure, but P. aeruginosa and S. marsescens were rapidly inactivated with no survivors after exposure to 2% glutaraldehyde. Since vigorous mechanical cleansing and more than 30 minute of contact time within washing machine, no more outbreak was observed. Conclusions: It is also very important that bronchoscopes must be meticulously cleaned after each procedure and more than 30 minute exposure would be required for eradication of MOTT with 2% glutaraldehyde. However even the most strictly applied infection control measures cannot exclude contamination completly and clinicians have to stay alert to this possibility. Prompt detection of pseudoepidemics is possible if abrupt increase in isolation rates, especially if they involve unusual or generally nonpathogenic organisms, are readily recognized.

• The Journal of Internal Korean Medicine
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• v.22 no.1
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• pp.79-85
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• 2001

Object : Hepatitis Treatment-tang No.1 has been used for the treatment of Liver disease and Jaundice. Long-term EtOH exposure leads to immunoregulatory and detoxification impairment. This study aimed to determine the relationship between TNF-${\alpha}$ production and expression, and EtOH-induced cytotoxicity on Hep G2 cells. Method : Cells were incubated with EtOH in the presence or absence of HT. The cells were tested after 24 hours and, again, after 48 hours. Cytoviability and TNF-${\alpha}$ release were analyzed by MTT assay and enzyme linked immunosorbent assay (ELISA), respectively. After 24 hours of EtOH exposure, the cytoviability decreased, and the release of TNF-${\alpha}$ was increased. Increased amounts of TNF-${\alpha}$ contribute to EtOH-induced cytotoxicity. The Anti-TNF-${\alpha}$ antibody almost abolished it. Interestingly, EtOH-induced cytotoxicity and TNF-${\alpha}$ production were inhibited by HT. Moreover, when HT was used in combination with the anti-TNF-${\alpha}$ antibody, there was a marked inhibition of EtOH-induced cytotoxicity. Results : These results suggest that HT may prevent the cytotoxicity through partial inhibition of the TNF-${\alpha}$ secretion.

• Nuclear Engineering and Technology
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• v.38 no.5
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• pp.449-454
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• 2006

Neutron imaging technique was used to investigate the water distribution and movement in Polymer Electrolyte Membrane Fuel Cell (PEMFC) at HANARO, KAERI. The Feasibility tests were performed in the first and second exposure rooms at the neutron radiography facility (NRF) at HANARO in order to check the ability of each exposure room, respectively. The feasibility test apparatus was composed of water and pressurized air before making up the actual test apparatus. Due to the low neutron intensity in the second exposure room, the exposure time was too long to investigate the transient phenomena of PEMFC. Although the exposure time was improved to 0.1 sec in the first exposure room, it was difficult to discriminate detail water movement at the channel due to the high noise level. Therefore, the experimental setup must be optimized according to the test conditions. Water discharge characteristics were investigated under different flow field geometries by using feasibility test apparatus and the neutron imaging technique. The water discharge characteristics of a 3-parallel serpentine are superior to those of a 1-parallel serpentine, but water at Membrane Electrode Assembly (MEA) was not removed, regardless of the flow field type.