• Journal of Preventive Medicine and Public Health
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• v.47 no.1
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• pp.18-26
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• 2014

The purpose of this study was to establish food ingestion factors needed to assess exposure to contaminants through food ingestion. The study reclassified the raw data of the Korean National Health and Nutrition Examination Survey in 2001 into 12 subcategories including grain products, meat products, fish and shellfish, and vegetables for international comparability of exposure evaluation. The criteria for food intake calculation were unified according to the characteristics of food groups, and recommended values for food ingestion factors were calculated through moisture correction and recategorization of cooked, processed, and mixed foods for each group. The average intake rate for grain and grain products was 6.25 g/kg-d per capita and the men's intake rate was approximately 8% higher than that of the women. The average intake rate of meat and meat products was 1.62 g/kg-d per capita and the men's intake rate was 30% higher than that of the women, on average. The average intake rate of fish and shellfish was 1.53 g/kg-d per capita, and the age groups of 1 to 2 and 3 to 6 recorded higher capita intake rates than other age groups, 2.62 g/kg-d and 2.25 g/kg-d, respectively. The average intake rate of vegetables was 6.47 g/kg-d per capita, with the age group of 1 to 2 recording the highest per capita intake rate of 9.79 g/kg-d and that of 13 to 19 recording the lowest mean. The study also offers recommended values for food ingestion factors of other food groups by gender, age, and region. The food ingestion exposure factors will need future updates in consideration of ongoing changes in food consumption behavior.

• Molecular & Cellular Toxicology
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• v.1 no.3
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• pp.203-208
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• 2005

Thioacetamide (TA) is potent haptotoxincant that requires metabolic activation by mixed-function oxidases. Micrcarray technology, which is massive parallel gene expression profiling in a single hybridization experiment, has provided as a powerful molecular genetic tool for biological system related toxicant. In this study we focus on the use of toxicogenomics for the determination of gene expression analysis associated with hepatotoxicity in rat liver epithelial cell line WB-F344 (WB). The WB cells was used to assess the toxic effects of TA. WB cells were exposed to two concentrations of TA-doses which caused 20% and 50% cell death were chosen and the cells exposed for periods of 2 and 24 h. Our data revealed that following the 2-h exposure at the both of doses and 24-h exposure at the low doses, few changes in gene expression were detected. However, after 24-h exposure of the cells to the high concentration, multiple changes in gene expression were observed. TA treatment gave rise predominantly to up-regulation of genes involved in cell cycle and cell death, but down-regulation of genes involves in cell adhesion and calcium ion binding. Exposure of WB cells to higher doses of the TA gave rise to more changes in gene expression at lower exposure times. These results show that TA regulates expression of numerous genes via direct molecular signaling mechanisms in liver cells.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2459-2465
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• 2012

Background: Numbers of epidemiological studies assessing residential radon exposure and risk of lung cancer have yielded inconsistent results. Methods: We therefore performed a meta-analysis of relevant published case-control studies searched in the PubMed database through July 2011 to examine the association. The combined odds ratio (OR) were calculated using fixed- or random-effects models. Subgroup and dose-response analyses were also performed. Results: We identified 22 case-control studies of residential radon and lung cancer risk involving 13,380 cases and 21,102 controls. The combined OR of lung cancer for the highest with the lowest exposure was 1.29 (95% CI 1.10-1.51). Dose-response analysis showed that every 100 Bq/$m^3$ increment in residential radon exposure was associated with a significant 7% increase in lung cancer risk. Subgroup analysis displayed a more pronounced association in the studies conducted in Europe. Studies restricted to female or non-smokers demonstrated weakened associations between exposure and lung cancer. Conclusions: This meta-analysis provides new evidence supporting the conclusion that residential exposure to radon can significantly increase the risk of lung cancer in a dose-response manner.

• Environmental Analysis Health and Toxicology
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• v.21 no.2 s.53
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• pp.115-126
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• 2006

This study was conducted to find out survival rate, activity, growth and change of the organ structure of bivalves exposed to heavy metal. The results of the study confirmed that zinc (Zn) induces reduction of survival rate and activity, abnormality of organ structure of the equilateral venus, Gomphina veneriformis. Experimental groups were composed of one control condition and three Zn exposure conditions ($0.64mg\;Zn{\iota}^{1},\;1.07mg\;Zn{\iota}^{-1},\;1.79mg\;Zn{\iota}^{-1}$). As the concentration of zinc increased the accumulation of lipofucin increased in the digestive gland. Survival rate was the lowest in the lowest Zn exposure group at $0.64mg;Zn{\iota}^{-1}$. Growth was not significantly different between the control and exposure group. Activity. with the exception of the lowest Zn exposure group at $0.64mg\;Zn{\iota}^{-1}$, was similar between the control and exposure group. Histological analysis of organ system illustrated expansion of hemolymph sinus, loss of striated border of inner epidermis, increase in the number of mucous cell in the mantle. Also, histological degenerations as epithelial necrosis and hyperplasia of mucous cells are recognized in the gill and foot.

• Journal of Aquaculture
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• v.18 no.3
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• pp.173-179
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• 2005

Superoxide dismutase (SOD), an antioxidant enzyme catalyzing the first step for scavenging the reactive oxygen species is important as an early warning indicator to address various biological stresses. For this reason, the monitoring the expressed pattern of SOD gene in fish organs is one of important biomarkers to assess the aquatic pollution caused by many toxic chemicals. Based on the Northern blot hybridization, semi-quantitative and/or realtime RT-PCRs, the alteration of SOD gene transcripts in shark liver was examined during the experimental acute exposures to cadmium. The expression of SOD at mRNA level was up-regulated both by injection (0, 0.5, 1 or 2 mg $CdCl_2/kg$ body weight for 48 hours) and by immersion (0 or $5{\mu}M$ Cd for 0, 1, 4 and 7 days) treatments of cadmium. The transcriptional stimulation of shark SOD gene by cadmium exposure was dependent upon doses and durations: there was a trend toward more increase in higher dose and longer durations of exposure. The hepatic SOD mRNA levels showed also a general agreement with the tissue cadmium concentrations accumulated in immersion exposure. This result may provide useful strategy to develop a fine molecular biomarker at mRNA level for detecting aquatic pollution caused by toxic metals.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.6
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• pp.750-755
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• 2017

Flatfish Paralichthys olivaceus raised in biofloc system (mean length $27.6{\pm}3.1cm$, mean weight $280.4{\pm}26.5g$) were exposed for to different concentrations of ammonia (0, 8, 16, 32, and $64mg\;{NH_4}^+/L$) for 7 days. Following ammonia exposure, hematological parameters such as hemoglobin and hematocrit were significantly reduced. Plasma components such as magnesium, glucose, aspartate aminotransferase (AST), and alanine aminotransaminase (ALT) were significantly altered by ammonia exposure, whereas there were no significant changes in calcium, cholesterol, or total protein. Antioxidant responses, such as superoxide dismutase (SOD) and catalase (CAT) levels were significantly elevated following ammonia exposure. The results of this study indicate that ammonia exposure induces significant changes in hematological parameters and antioxidant responses in biofloc-reared Paralichthys olivaceus as a toxic response.

• Journal of Nutrition and Health
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• v.39 no.6
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• pp.539-548
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• 2006

In recent years a concern of excessive intakes of vitamins and minerals from various sources is increasing, since there has been a marked increase in production and consumption of vitamin and mineral supplements and fortified foods. The purpose of this study was to assess the maximum exposure of vitamins and minerals from various sources including diet, fortified foods, and health functional foods among Koreans. As a result, the highest exposure group of most vitamins and minerals from diet was adults (30 - 49 years of age) according to 2001 Korean National Nutrition and Health Survey Report. Maximum dietary intakes of vitamin A, $B_1,\;B_2$, C, nicotinamide, calcium, phosphorus and iron were 0.5 - 7 times of the RDA for Koreans, 7th ed. Maximum intakes of vitamins and minerals from fortified foods by adults (20 - 59 years of age) were 8 - 760% of the Korean RDA. In addition, maximum exposure of vitamins and minerals from vitamin mineral health functional foods by middle aged people was 35 - 140% of the upper limits (UL: DRI for Koreans). As a consequence, maximum combined intakes of vitamin $B_6$, vitamin C, calcium, iron and zinc from the above sources including diet, fortified foods and vitamin mineral health functional foods were greater than the UL. These results would be applied for determining the safe upper limits of vitamin and mineral of health functional foods.

• Journal of radiological science and technology
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• v.18 no.2
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• pp.49-59
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• 1995

Recently, general radiography became to variety because of the continuous development of Inverter type generator and ortho chromatic system. Therefore, we must re-evaluate about patient exposure dose and image quality. I studied about chest radiography which has frequency among general radiography being used during FEB. to AUG., 1994 over 151 medical facilities from medical facilities that are located in Seoul area. The result obtained were as follows ; 1) The rectification method of the generator were employing mainly single phase full wave in 82.8 %, three phase full wave in 11.26 % and Inverter type in 4.64 % and condenser type is 1.32 %. 2) Exposure kV was used below 80 kV in most medical facilities and 21.8 % of the medical facilities was using high tube voltage higher than 120 kV. 3) The exposure time was used below the 0.05 sec in 28.4 %, in 29.8 % of the medical facilities used above 0.1 sec. 4) The usage frequency of the added filter is 15.3 %, and among them compound filter was used only 4 %. 5) Rare earth screen was used in 37.7 %. 6) The average skin entrance dose was 0.25 mSv, the range of dose is $0.05{\sim}0.79\;mSv$ in each medical facilities. 7) The average density of the lung field is 1.76, 0.49 in lung side, 0.30 in mediastinum and 0.37 in heart shadow. Therefore it is required to improve all of these for increasing image quality and reducing patient exposure dose as soon as possible.

• Journal of Digital Convergence
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• v.18 no.1
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• pp.241-247
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• 2020

The effect of radiofrequency radiation (RF) exposure on mouse associated with the exercise was investigated in the brain at the molecular level. The expression of tyrosine hydroxylase(TH), FoxO3a, AMPKα and mRNA was investigated by real-time RT-PCR in striatum and the hypothalamus. In the striatum, TH mRNA expression was decreased in the exercise and RF exposure group. FoxO3a mRNA expression was significantly increased in the spontaneous exercise group and a significant decrease was observed in the RF exposure and spontaneous exercise group. In the hypothalamus, TH mRNA expression was significantly decreased in the RF exposure and spontaneous exercise group. But, FoxO3a mRNA expression was significantly increased in the RF exposure and spontaneous exercise group. We will further investigate the expression of protein molecules in the hippocampus of the brain to reveal the effects of RF radiation on memory.

• Journal of the Korea Convergence Society
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• v.8 no.9
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• pp.211-216
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• 2017

The purpose of this study is to evaluate the usefulness of a newly fusion model designed cloak shield to reduce the radiation exposure of the assistant during CT(computed tomography) of severely injured patient. Radiation dose was measured in the heart, both axillary and thyroid areas using newly designed cloak shield and existing shield with head phantom and human phantom under the same conditions as brain vascular CT scan. The newly designed cloak shield was measured higher for radiation shielding rate than the existing shields, 61.9 % for heart, 46.2 % for left axillary, 69.8 % for right axillary and 71.1 % for thyroid gland, respectively. a newly developed fusion model of cloak shields are useful for reducing radiation exposure. It is expected to make a significant contribution to reduction of radiation exposure.