• Journal of the Korean GEO-environmental Society
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• v.13 no.10
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• pp.15-23
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• 2012

A numerical model and field monitoring data are used to estimate a change in groundwater level at a borrow site, which will be constructed at the mountainous area with a large ground excavation in the study area, Hwaseong city. Lithologic data and hydraulic coefficients are collected at 9 boreholes and also groundwater levels are measured at these boreholes and existing wells in the study area. Additionally, groundwater recharge rate for the type of land cover is estimated using water budget analysis; 133.34mm/year for a mountainous area, 157.68mm/year for a farming area, 71.08mm/year for an urbanized area, and 26.06mm/year for a bedrock exposure area. The change in groundwater level in and around a borrow site is simulated with Modflow using these data. The result of a transient model indicates that a removal of high ground (over 40El.m) by an excavation will produce a decrease in groundwater levels, up to 1 m, around a borrow site in 10 years. It also explains that this ground excavation will bring about the decreases of 9.4% and 7.0% for groundwater recharge and surface runoff, respectively, which are the factors causing groundwater level's change. This study shows that it is required to construct the groundwater monitoring wells to observe the change of groundwater near a borrow site.

• International Journal of Oral Biology
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• v.31 no.1
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• pp.15-20
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• 2006

Concerns remain regarding the biocompatibility and adverse effects of dental casting alloys. The aim of this study was to understand the cytopathogenic effect of metal ions, which might be released from dental alloys, on oral squamous carcinoma(OSC) cells. The cellular morphology, viability, the type of cell death and molecular change in response to metal ion salt solutions including aluminum(Al), cobalt(Co), copper(Cu) and nickel(Ni) were examined. The $TC_{50}$ values for the metal ions with the exception of AI were estimated to be between 400 and $600{\mu}M$. The cells treated with the metal ions showed apoptotic change with the exception of Al ions. Metal ion-induced apoptosis was further confirmed using flow cytometric analysis. This study showed that the cytotoxicity and the mode of cell death by metal ions clearly depend on the cell type, the type of metal ion and the duration of exposure. The protein level of Rb, a tumor suppressor that affects apoptosis para-doxically, was higher in the cells treated with Co, Cu and Ni. It is believed that apoptosis and cell damage in the OSC cells treated with Co, Cu or Ni can be evoked by the regulation of Rb.

• Environmental Analysis Health and Toxicology
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• v.25 no.1
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• pp.57-68
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• 2010

This study assessed the lifetime cancer and non-cancer risk of aldehydes and volatile organic compounds exposure of young children at child-care facilities and indoor playgrounds in Korea. The samples were collected at various children's facilities (40 day-care houses, 42 child-care centers, 44 kindergartens, and 42 indoor playgrounds) in summer (Jul~Sep, 2007), winter (Jan~Feb, 2008) and Spring (Mar~Apr, 2008) periods, and analyzed by GC-MS. We estimated the lifetime excess cancer risks (ECRs) of formaldehyde, acetaldehyde, benzene, chloroform, CCI4 and tetrachloroethylene, and the hazard quotients (HQs) of Non-carcinogens (toluene, xylene, benzaldehyde and formaldehyde). Formaldehyde evaluated both cancer and non-cancer risk. The average ECRs of formaldehyde for young children were $1\times10^{-4}{\sim}1\times10^{-5}$ level in all facilities. HQs of four non-carcinogens did not exceed 1.0 for all subjects in all facilities.

• Environmental Analysis Health and Toxicology
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• v.19 no.2
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• pp.191-200
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• 2004

Zinc (Zn) is an essential element in biological process, however inadequate Zn status in general population have been recognized. To update the knowledge for Zn-cadmium (Cd) interaction, we studied the intestinal uptake and transport, and the expression of metal transporter proteins (divalent metal transporter 1, DMT1 ; metal transporter protein 1, MTP1 ; zinc transporter 1, ZnTl ; metallothionein 1 , MT1) in duodenum after Cd exposure using Zn deficient animal model. Rats were led Zn deficient (ZnD, 0.5-1.0 mgZn/kg) or Zn supplemented (ZnS, 50mg Zn/kg) diet for 4 weeks, and followed single administration of $^{109}$ CdCl$_2$orally. The body Zn flatus and tissue Cd concentration were determined at 24 hrs after Cd administration. Total body burden of Cd and Cd absorption index (AI, %) were estimated based on the tissue Cd analyzed. DMT1, MTP1, ZnTl and MT1 mRNA were analyzed by using RT-PCR method. Feeding of Zn deficient diet for 4 weeks produced a reduced body weight gain and a depletion of body Zn. Tissue Cd concentration, body burden of Cd and Cd absorption index were higher in the ZnD diet fed rats than the ZnS diet red rats. Especially, Cd concentration in the small intestine (duodenum, jejunum and ileum) and the colon of FeD diet fed rats were higher markedly than in the FeS diet group. The expression levels of DMT1, MTP1 and ZnT1 mRNA in FeD diet fed rats were similar to the FeS diet. The level of MT1 mRNA expression was significantly lower in the FeD than the FeS diet fed rats. Taken together, theses results indicate that Zn deficiency in diet induce an increased intestinal absorption and tissue retention of Cd, and down -regulate the MT1 expression in the intestine which might be play a part of role in Cd absorption and transport in mammalian. These findings suggest that deficiency of essential metal could be enhanced the toxicity of toxic, non-esstial metals through the metal-metal interaction.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.2
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• pp.65-73
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• 2011

In this paper, we present a novel digital multifocusing approach using adaptive region-based histogram equalization for the multiple color-filter aperture (MCA) system with insufficient amount of incoming light. From the image acquired by the MCA system, we can estimate the depth information of objects at different distances by measuring the amount of misalignment among the RGB color planes. The estimated depth information is used to obtain multifocused images together with the process of the region-of-interests (ROIs) classification, registration, and fusion. However, the MCA system results in the low-exposure problem because of the limited size of the apertures. For overcoming this problem, we propose adaptive region-based histogram equalization. Based on the experimental results, the proposed algorithm is proved to be able to obtain in-focused images under the low light level environment.

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.317-322
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• 2003

Cytogenetic and hematological analysis was performed in peripheral blood from the Korean native goat bred in the nuclear power plant (Wolsong and Uljin) and control area. The frequency of micronuclei (MN) in peripheral blood lymphocytes from goat was used as a biomarker of radiobiological effects resulting from exposure to environmental radiation. An estimated dose of radiation was calculated by best fitting linear-quadratic model based on the radiation-induced MN data over the range from 0 to 4 Gy from the goat lymphocytes with in vitro irradiation. MN rates in goats from the Wolsong and Uljin nuclear power plant, and control area were 9.60/1000, 6.83/1000 and 9.88/1000, respectively. There were no significant differences in MN frequencies and hematological values in goats between nuclear power plant and control area. High level of platelet in the goat from Uljin nuclear power plant was observed, which seemed to be related to the goat management.

• Food Science of Animal Resources
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• v.35 no.5
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• pp.674-682
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• 2015

The objective of this study was to evaluate the risk of illness from Campylobacter spp. on ham. To identify the hazards of Campylobacter spp. on ham, the general characteristics and microbial criteria for Campylobacter spp., and campylobacteriosis outbreaks were investigated. In the exposure assessment, the prevalence of Campylobacter spp. on ham was evaluated, and the probabilistic distributions for the temperature of ham surfaces in retail markets and home refrigerators were prepared. In addition, the raw data from the Korea National Health and Nutrition Examination Survey (KNHNES) 2012 were used to estimate the consumption amount and frequency of ham. In the hazard characterization, the Beta-Poisson model for Campylobacter spp. infection was used. For risk characterization, a simulation model was developed using the collected data, and the risk of Campylobacter spp. on ham was estimated with @RISK. The Campylobacter spp. cell counts on ham samples were below the detection limit (<0.70 Log CFU/g). The daily consumption of ham was 23.93 g per person, and the consumption frequency was 11.57%. The simulated mean value of the initial contamination level of Campylobacter spp. on ham was −3.95 Log CFU/g, and the mean value of ham for probable risk per person per day was 2.20×10⁻¹². It is considered that the risk of foodborne illness for Campylobacter spp. was low. Furthermore, these results indicate that the microbial risk assessment of Campylobacter spp. in this study should be useful in providing scientific evidence to set up the criteria of Campylobacter spp..

• Tuberculosis and Respiratory Diseases
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• v.50 no.5
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• pp.615-623
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• 2001

Background : Pneumoconiosis is a parenchymal lung disease that results from the accumulation of coal dust in the lungs and the consequent tissue reaction. To evaluate the role of various personal factors in pneumoconiosis and the significance of some serologic markers for assessing the disease activity related to pneumoconiosis, the Rheumatoid Factor(RF), ${\alpha}_1$-AT, C-Reactive Protein(CRP), ceruloplasmin and fibrinogen levels were measured. Method : All the patients were males, 45-76 years old, and the mean duration of coal dust exposure was 23.2 years. 51 patients were classified as having Simple Pneumoconiosis (SP), 59 had Progressive Massive Fibrosis (PMF). Fifty eight men with ages ranging from 26-70 years were used as normal controls. The serum RF and CRP were titrated using an Autochemistry analyzer (HITACHI 7150 : Japan) and the ${\alpha}_1$-AT and ceruloplasmin levels were measured using a Nephelometer (Behring Nephelometer : Germany) and the fibrinogen levels were estimated by using an Autoanalyzer for hematologic coagulation. Result : There was a higher RF level in the SP, and PMF groups than in the control groups but there was no statistical difference. The CRP, ${\alpha}_1$-AT, and ceruloplasmin levels were also higher in the SP, and PMF groups. However, the fibrinogen concentration was within the normal ranges in both the SP and PMF groups. Conclusion : The CWP (Ed note : Define CWP) patients had significantly higher CRP, ${\alpha}_1$-AT, and ceruloplasmin levels compared to the control group. It is believed that these serologic changes could be used as a marker of the disease activity.

• Journal of the Korea Safety Management & Science
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• v.17 no.2
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• pp.55-66
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• 2015

In the perspective of industrial health management, it is important for the employee to decrease their job stress, to improve their productivity and quality of labor. In this study, the job stress, and it's influence on PWI(Psychosocial Wellbeing Index) were investigated by the questionnaire survey of 138 industrial workers who had studied assistive technology in college. The contents of questionnaire consist of the demographic characteristics, job-related characteristics, job stress and psycho-social stress. We evaluated job stress by KOSS-SF(Korean Occupational Stress Scale-Sort Form) and psychosocial stress by PWI-SF(Psychosocial Well-being Index-Short Form). To analyze the results, we evaluated the exposure level of KOSS and PWI by demographic characteristics and job-related characteristics using significance tests. Also, we estimated the relationship among demographic characteristics, job-related characteristics, job stress and psychosocial stress, using correlation analysis. As a results, all workers were found to be in a group under the high risky stress. It showed that the scale index of female's job non-autonomy and pwi were much larger than those of male's. Therefore, to guarantee job autonomy of female workers should be more emphasized, to improve their working environment. Job type had significant relationships with many job stress category; physical environment, job demand, job instability and organization culture. Regarding pwi, the scale index of the workers who is in charge of the civil service such as contacting the disabled and the aged in person, were much larger than that of the other workers. Accordingly, the job stress management program including physical environment, job demand, job instability and organization culture, should be suggested, to decrease the stress of the workers in charge of the disabled and the elders service. The strongest predictors of pwi was organization system through maximum positive relations between organization system and pwi. Therefore, it indicates that improvement of organization system such as a fair merit rating, a manpower supply, demand plan and department cooperation is urgently needed to reduce pwi.

• Environmental Analysis Health and Toxicology
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• v.25 no.3
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• pp.181-186
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• 2010

Perfluorinated Compounds (PFCs) are anthropogenic compounds found in trace amounts in many environmental compartments far from areas of production. Along with the highly persistent nature of PFCs, there are increasing concerns over the potential adverse effects of them on the ecosystems. Most of highly fluorinated compounds degrade into PFOS and PFOA that are very stable compounds hard to break down. So, in this study, we tried to determine the toxicity of PFOS and PFOA in the terrestrial invertebrate. Acute toxicity test using earthworm, Eisenia fetida, was performed according to the OECD test guideline 207 (Earthworm, Acute Toxicity Tests). In the 14 day acute toxicity tests, the highest concentration causing no mortality and the lowest concentration causing 100% mortality of PFOS were 160 and 655 mg/kg (dry weight), respectively. And the highest concentration causing no mortality and the lowest concentration causing 100% mortality were 500 and 1,690 mg/kg (dry weight), respectively in the PFOA-exposure group. 14 day-LC50 values were estimated at the level of 365 and 1,000 mg/kg (dry weight) in the PFOS and PFOA-exposed group. These results indicate that under laboratory conditions PFOS is about 3 times more toxic to earthworms than PFOA. Based on known environmental concentrations of PFOS in the soil of Korea, which occur in the 0.42~0.73 ng/L range, there is no apparent risk to terrestrial invertebrate, earthworms. However, further work is required to investigate long-term effects on these and other terrestrial organisms.