• Toxicological Research
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• v.31 no.3
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• pp.255-264
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• 2015

Heterocyclic amines (HCAs) and acrylamide are unintended hazardous substances generated by heating or processing of foods and are known as carcinogenic and mutagenic agents by the animal experiments. A simple method was established for a rapid and accurate determination of 12 types of HCAs (IQ, MeIQ, Glu-P-1, Glu-P-2, MeIQx, Trp-P-1, Trp-P-2, PhIP, $A{\alpha}C$, $MeA{\alpha}C$, Harman and Norharman) and acrylamide in three food matrices (non-fat liquid, non-fat solid and fat solid) by isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS). In every sample, a mixture of internal standards including $IQ-d_3$, $MeIQx-d_3$, $PhIP-d_3$, $Trp-P-2-^{13}C_2-^{15}N$ and $MeA{\alpha}C-d_3$ was spiked for quantification of HCAs and $^{13}C_3$-acrylamide was also spiked for the analysis of acrylamide. HCAs and acrylamide in sample were extracted with acetonitrile and water, respectively, and then two solid-phase extraction cartridges, ChemElut: HLB for HCAs and Accucat: HLB for acrylamide, were used for efficiently removing interferences such as pigment, lipid, polar, nonpolar and ionic compounds. Established method was validated in terms of recovery, accuracy, precision, limit of detection, limit of quantitation, and linearity. This method showed good precision (RSD < 20%), accuracy (71.8~119.1%) and recovery (66.0~118.9%). The detection limits were < 3.1 ng/g for all analytes. The correlation coefficients for all the HCAs and acrylamide were > 0.995, showing excellent linearity. These methods for the detection of HCAs and acrylamide by LC-MS/MS were applied to real samples and were successfully used for quantitative monitoring in the total diet study and this can be applied to risk assessment in various food matrices.

• Food Science and Preservation
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• v.22 no.4
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• pp.559-566
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• 2015

The aim of this study was to develop an analytical method for determination of T-2 toxin and HT-2 toxin level in cereals and to survey their levels using LC-MS/MS. The T-2 and HT-2 toxins were simultaneously analyzed by electrospray ionization with a positive ion mode and multiple reaction monitoring (MRM) after filteration and immuno-affinity column clean-up. A matrix-matched standard calibration used for quantification and recoveries of T-2 and HT-3 toxins were in the range of $100.6{\pm}7.2%$ and $96.8{\pm}9.4%$, respectively. Limits of detection and quantification of T-2 and HT-2 toxins were estimated to be 0.5 and $1.5{\mu}g/kg$, respectively. Each repeatability (RSRr) of T-2 and HT-2 toxins was determined to be 0.9~6.0%, and 4.9~6.1%, respectively. Total 115 samples cereals were collected from 9 types of cereals for analysis. The positive percentages of T-2 and HT-2 toxins obtained from collected samples were found to be 72% and 80%, respectively. The contamination level of T-2 toxin and HT-2 toxin in cereals were $37.1{\mu}g/kg$, and $5.4{\mu}g/kg$, respectively. Therefore, this study suggests that the developed method could be an useful analytical method to determine the T-2 and HT-2 toxin level in cereals and the present data could be used as a reference to estimate the risk assessment.

• Korean Journal of Ecology and Environment
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• v.47 no.2
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• pp.82-90
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• 2014

To assess the adverse effects of suspended solids on fishes, the hatching rate of embryo, and survival and growth of larvae were measured with common fish species of river such as crusian carp (Carassius auratus), common carp (Cyprinus carpio) and medaka (Oryzias latipes). Bioassay on hatching rate of embryo was conducted with a range of turbidity as 10 levels from 0.2 to 8,080 NTU. Another bioassay on 4-day larval survival and 21-day larval growth were also conducted with a range of turbidity as 8 levels from 0.1 to 8,260 NTU, and 6 levels from 0.7 to 2,030 NTU, respectively. The hatching rate of C. auratus was not significantly different from that of control at turbidity below 4,040 NTU, whereas it decreased when turbidity was 8,080 NTU (p<0.05). The hatching rate of C. carpio was not affected by concentration of suspended solids. For O. latipes, the hatching rate significantly decreased from 254 NTU (p<0.001) and it was zero when turbidity was 8,080 NTU. The 4-day survival of larvae of all 3 species was not affected by turbidity, while the larval growth of all 3 species was significantly affected. The turbidity effect on the growth of C. auratus and C. carpio was observed from 7 days after the exposure at turbidity level of 145, 143 NTU, respectively. The turbidity effect on the growth of O. latipes was observed from 14 days after the exposure at turbidity level of 254 NTU. The results of this study will provide the basic information for the derivation of water quality criteria on suspended solids for the protection of aquatic ecosystem and the quantitative ecological risk assessment of freshwater environment.

• Journal of the Korean Chemical Society
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• v.61 no.2
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• pp.51-56
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• 2017

N-nitrosamines are the nitroso compounds which are produced by nitrosation reactions of the secondary amine and nitrite under acidic conditions. Approximately 300 species of N-nitrosamine have been tested for carcinogenicity in laboratory experiments, with 90% of them demonstrated carcinogenic effects different animal species, including higher primates. In 1978, IARC classified NDMA and NDEA as Group 2A, and NDPA, NDBA, NPIP, NPYR and NMOR as Group 2B. In this study, we established pretreatment and analytical method for N-nitrosamines (NDMA, NDEA, NMEA, NDPA, NDBA, NPIP, NPYR and NMOR) in human urine for biological monitoring of N-nitrosamines. The analytes were extracted using solid phase extraction (SPE), then quantitative analysis was performed by LC-(APCI)-MS/MS. The accuracies of the established method were between 85.8~108.7% and precisions were lower than 20%. The limit of detection (LOD) were between 0.0002 (NDBA) and 0.0793 (NDMA) ng/ml. The linearity obtained was satisfying for the 8 N-nitrosamines, with a coefficient of determination ($r^2$) higher than 0.999. The mean concentrations of N-nitrosamines in the urine were 2.645 mg/g creatinine for NDMA, 0.067 mg/g creatinine for NDEA, 0.009 mg/g creatinine for NMEA, 0.011 mg/g creatinine for NDBA, 0.271 mg/g creatinine for NPIP and 0.413 mg/g creatinine for NPYR. NDPA and NMOR were not detected. It can be used as a instrumental methodology for evaluation and risk assessment of human exposure to N-nitrosamines for the further research.

• Journal of Korean Society for Geospatial Information Science
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• v.23 no.1
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• pp.23-29
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• 2015

In this study, the spatial relevance between the regional housing price data and the spatial distribution of the location-based social media data is explored. The spatial analysis with rasterization was applied to this study, because the both data have a different form to analyze. The geo-tagged Twitter data had been collected for a month and the regional housing price index about sales and lease were used. The spatial range of both data includes Seoul and the some parts of the metropolitan area. 2,000m grid was constructed to consider the different spatial measure between two data, and they were combined into the constructed grids. The Hotspot Analysis was operated using the combined dataset to see the comparison of spatial distribution, and the bivariate spatial correlation coefficients between two data were measured for the quantitative analysis. The result of this study shows that Seocho-gu area is detected as a common hotspot of tweet and housing sales price index data. though the spatial relevance is not detected between tweet and housing lease price index data.

• Korean Journal of Construction Engineering and Management
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• v.15 no.3
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• pp.23-30
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• 2014

Overseas construction orders of domestic companies had been increased significantly in a short period from $10.9 billion in 2005 to $64.9 billion in 2012. However experts are concerned that quality of growth will not support quantitative growth. This study suggest concentrate competencies for not only winning in bid but also successful execution of domestic companies. 4 Steps which are Pre-Marketing, Bid-Preparation, Bidding, Contract Phase are defined for competency assessment. After drawing specific tasks by phase, survey asking importance and capability of the tasks to the person in charge of bidding and site was conducted by utilizing Likert 7 point scale. According to the result of IPA analysis, domestic construction companies need to ensure internal competencies; Project risk review, Bid team organization, and external competencies; Client needs grasp, Localization strategy, Cooperation establishment. Hearafter domestic construction companies will be able to utilize the result of the study for setting bidding strategy for winning in bid and improving earning rate.

• Journal of Food Hygiene and Safety
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• v.19 no.1
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• pp.49-54
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• 2004

The prevention of infectious disease from contaminated foods is very important in public health. Quantitative microbial risk assessment has been used in advance countries to achieve the safety of public health against hazardous microbial causing contaminated foods. This study was conducted to estimate maximum edible time without producing enterotoxin from Staphylococcus aureus in Kimbap selling at different domestic store using Food MicroModel and monitoring data and to compute maximum edible time by temperature with 99th percentile safety probability based on only restaurant data. For estimating maximum edible time, model operation conditions like reaching time at 2 ${\times}$ 10$^{7}$ , which enterotoxin was known as producing point from S. aureus, temperature of 28∼3$0^{\circ}C$, pH 5.2, NaCl 0.22%, aw(water activity) 0.99, and intaking one serving size of 171g in Kimbap were considered. Estimated maximum edible times by regarding outdoor temperature in summer were 3.9∼4.6 hrs in restaurant, 6.7∼7.9 hrs in department store and 7.4∼8.7 hrs in convenient store. Based on restaurant data, estimated maximum edible times with 99th percentile safety probability by temperature were 1.9 hrs in 3$0^{\circ}C$ and 17.7 hrs in 15$^{\circ}C$.

• Food Science and Industry
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• v.50 no.2
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• pp.37-51
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• 2017

Food packaging strategies have steadily improved with increasing demand for improved food safety, convenience, and shelf life. The development of edible film has been hailed as a technology substituting packaging using synthetic plastics. There has been a surge for research to develop antimicrobial edible films and coatings that can increase microbiological safety while preserving foods. This review addresses recent results that are useful in advancing and extending research into antimicrobial edible films. In this review, we suggest the trend of the development of antimicrobial edible film/coatings by outlining edible film materials, antimicrobial substances, antimicrobial and physical properties of the films, commercial antimicrobial edible films, and methods to statistically predict the efficacy of antimicrobial edible film/coatings, reported in recent studies.

• Journal of the Society of Disaster Information
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• v.18 no.4
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• pp.861-872
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• 2022

The purpose of this study was to establish a complex disaster scenario that can comprehensively consider various disaster situations that may occur in the utility tunnel. Method: In order to comprehensively consider the correlation between disasters, a composite disaster scenario was derived from a combination of damage factors, respectively. A risk assessment was performed in order to derive the priorities of the scenarios. And based on the results, the priorities of complex disaster scenarios were set. Result: Based on the disaster cases in the utility tunnel, a plan was prepared for complex disaster scenarios centered on damage. A complex disaster scenario was specified using a semi-quantitative evaluation method for single and multiple disaster factors such as fire, flooding, and earthquake. Conclusion: The composite disaster scenario derived from this study can be used for the prevention and preparation of damage when the precursor symptoms of a disaster are detected. In addition, the results of this study are expected to be used as basic data for preparing strategic plans and preparing complex disaster response technologies to induce rapid response and recovery in case of emergency disasters.

• Journal of Industrial Convergence
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• v.21 no.6
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• pp.37-42
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• 2023

This study aimed to examine the safety of HemoHIM, a dietary supplement containing methoxsalen. HemoHIM is a dietary supplement marketed globally, and a competitor to ginseng. It has been reported to contain methoxsalen, a plant extract for treating psoriasis and vitiligo. Methoxsalen is known to cause hepatotoxicity, but most of the cases has been reported from ingestion as a drug, not a food. There are no reports of hepatotoxicity from the consumption derived from natural products such as Angelica gigas, Cnidium officinale, and Paeonia lactiflora, which are the main ingredients in the HemoHIM. However, a recent case of acute hepatitis was reported in Hong-Kong after ingestion of HemoHIM. It is difficult to conclude that hepatitis was caused by HemoHIM, because there was no check of co-occurring medications with a higher risk of hepatotoxicity, no description of the progress, no quantitative comparison of methoxsalen in HemoHIM to it in common foods such as carrots and celery, and no description of the patient's underlying diseases. On the other hand, there was a study that suggest hemoHIM is safe, and that study had adequate number of subjects even though more studies are needed to ensure safety.