• Journal of Food Hygiene and Safety
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• v.23 no.4
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• pp.285-290
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• 2008

This study was carried out to examine microbiological contamination of ready-to-eat foods (kimbab, sushi, salad, sandwich, sashimi) and to prove hazard of ready-to-eat foods by microbiological analysis. Collection of 440 samples of ready- to-eat foods were obtained from department stores, discount stores, super-markets in Seoul, Gyeonggi, Chungcheong, Gyeongsang, Honam areas. Sushi showed the highest detection rate of micro organism with value of20.4%, and then detection rates of kimbab, sashimi and salad were 13.0%, 12.5% and 6.9%, respectively. S. aureus was the most detected microorganism with value of 6.6%, and then Coliform and L. monocytogenes were detected 2.7% and 2.3%.

• YAKHAK HOEJI
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• v.55 no.2
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• pp.81-90
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• 2011

Most antineoplastic agents are nonselective in their mechanism of action, affecting noncancerous as well as cancerous cells, and resulting in acute effects such as irritation of mucous membranes and chronic effects such as genotoxicity, teratogenicity, and carcinogenicity. Healthcare workers occupationally exposed to antineoplastic agents are at risk. The present study aimed to develop and apply methods to monitor occupational exposure to antineoplastic agents, using cyclophosphamide (CP) as the model compound. To monitor environmental and biological exposure, potentially contaminated surfaces were wiped and 24 hour urine samples were collected from workers. Liquid chromatography combined with tandem mass spectrometry was performed, with a limit of detection of 0.05 ng/ml. Measurable amounts of CP were detected on 92% of the sampled surfaces, with a geometric mean of 175.22 $ng/m^2$. Despite the environmental contamination of the model compound, CP was below the detection limit in all urine samples. If workplace contamination cannot be completely avoided, it is importance to reduce exposure to the lowest possible levels. To this aim, efforts to minimize occupational exposure along with biological and environmental monitoring are required. The standardized sampling techniques, and specific and sensitive analytical methods reported in this study may be helpful in assessing occupational exposure and devising strategies to reduce exposure.

• Korean Journal of Ecology and Environment
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• v.36 no.2 s.103
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• pp.97-107
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• 2003

Fish vitellogenin produces in female liver during oogensesis through estradiol cycle, and produces even in male liver by endocrine-disrupting chemicals (EDCs) such as alkylphenols. The resulting effects of EDCs lead to the low fecundity of female and the feminization (eg. shrinkage of testis) in male. Especially, the production of vitellogenin in male indicates the environmental contamination of EDCs, resulting in the modulation of gene expression profiles and the monitoring of environmental contamination at specific area. In this paper, we suggest that fish vitellogenin is useful for biomonitoring for environmental contamination and would be substantially useful as a biomarker for a detection of EDCs in aquatic environment.

• The Journal of the Convergence on Culture Technology
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• v.9 no.2
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• pp.561-568
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• 2023

Various defects occur in concrete structures due to internal and external environments. If there is a defect, it is important to efficiently identify and maintain it because there is a problem with the structural safety of concrete. However, recent deep learning research has focused on cracks in concrete, and studies on exfoliation and contamination are lacking. In this study, focusing on exfoliation and contamination, which are difficult to label, four models were developed and their performance evaluated through unlabelling method, filtering method, the convergence of transfer learning based k-means clustering. As a result of the analysis, the convergence model classified the defects in the most detail and could increase the efficiency compared to direct labeling. It is hoped that the results of this study will contribute to the development of deep learning models for various types of defects that are difficult to label in the future.

• Journal of dental hygiene science
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• v.23 no.4
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• pp.343-350
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• 2023

Background: Digital panoramic dental X-ray equipment (PDX) is frequently used by patients and dental workers for diagnosis and examination in dental institutions; however, infection control has not been properly implemented. Therefore, in this study, we aimed to systematically review the potential risk of cross-infection in the dental environment by investigating the contamination level of general aerobic bacteria and Staphylococcus aureus, which are important in hospital infections, in PDX areas that people mainly contact. Methods: This survey was conducted from March to May 2023 and covered one general hospital, three dental hospitals, and nine dental clinics equipped with PDX. Bacteria samples were collected from the left-handle, right-handle, forehead support, and head side support as the patient's contact areas, as well as the X-ray exposure switch and left-click mouse button as the dental hygienist's contact areas of the PDX. The collected bacteria were spread on Petrifilm, and colonies formed after 48 hours of culture were counted. Results: General aerobic bacteria and S. aureus were detected in all areas investigated. Significant differences in bacterial counts between different regions of the PDX were observed in both groups (p<0.001). The detection rates of general aerobic bacteria (p<0.001) and S. aureus (p<0.001) were significantly higher in the contact areas of patients than those of dental hygienists. A positive correlation was observed between the forehead and the temple region in terms of general aerobic bacteria and S. aureus detection (r=1) (p<0.01). Conclusion: Taken together, the presence of many bacteria, including S. aureus, detected in PDX indicates that PDX has a potential cross-infection risk. Our results therefore highlight the need for the development of appropriate disinfection protocols for reusable medical devices such as PDX and periodic infection prevention training for hospital-related workers, including dental hygienists.

• Journal of Soil and Groundwater Environment
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• v.23 no.1
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• pp.30-40
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• 2018

To evaluate potential impacts of shallow groundwater by the leachate from buried carcass, we investigated hydrochemical characteristics of both leachate and shallow groundwater from monitoring wells and surrounding shallow groundwater wells in an area potentially affected by pig carcass burial. The hydrochemical survey was conducted before and after the relocation of a burial pit. The leachate samples and the groundwater affected by leachate showed the hydrochemistry of $Ca-HCO_3$ type with high $NH_4{^+}$ concentrations, while unaffected groundwater was mostly the $Ca(Na)-Cl+NO_3$ type due to pervasive impacts from agrochemicals. The results of factor analysis on hydrochemical data showed the followings: 1) contamination of groundwater from agro-livestock farming and livestock burial are coexisting in the study area, 2) among ionic species, $HCO_3{^-}$, $NH_4{^+}$, $NO_3{^-}$ and Mn are very useful to differentiate the groundwater contamination from leachate, and 3) groundwater contamination by leachate has been recognized around the monitoring wells even after the relocation of a burial pit, likely due to residual contaminants in surrounding soils. Therefore, it is suggested that continued monitoring of groundwater contamination should be conducted after the relocation of carcass burial pits.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.3
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• pp.189-192
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• 2009

Purpose: Autopipetting system is an efficient automated equipment pipetting patient samples and reagents for rapid and accurate test. However, it can cause carryover between high concentration sample and low concentration sample. We evaluated carryover contamination of TECAN freedom Evo 100 autopipetting system. Materials and Method: We studied carryover contamination of $\alpha$-fetoprotein (AFP) and carcinoembryonic antigen (CEA) test on TECAN freedom Evo 100 autopipetting system. Very low concentration control samples were pipetted for comparison to the contaminated very low concentration samples. Then, The contaminated very low concentration samples were pipetted following the high concentration samples were pipetted alternately. The difference of low concentration samples represents carryover. The target value to decide carryover was 1ppm (parts per million). Results: For AFP, the mean values of the uncontaminated control samples and the contaminated samples were less than 0.6 IU/mL (the l imit of detection (LoD)). Carryover did not occur even though the high concentration sample which value was 650000 IU/mL. For CEA, the values of the low concentration control samples and the contaminated samples were less than 0.2 ng/mL (LoD). Carryover did not occur even though the high concentration sample which value was 65,000 ng/mL. Conclusions: Sample carryover was not found on TECAN freedom Evo 100 autopipetting system for AFP, CEA. However, carryover is a potential problem with automated instruments and robotic pipetting systems. Therefore, Clinical laboratories must periodically verify carryover contamination for the accurate and confidential test results.

• Research in Plant Disease
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• v.13 no.3
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• pp.145-151
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• 2007

Xanthomonas axonopodis pv. glycines is the causal agent of bacterial pustule of soybean(Glycine max. (L.) Merr), which is one of the most prevalent bacterial diseases in Korea. In this study, Polymerase Chain Reaction (PCR) assay was applied to detect Xanthomonas axonopodis pv. glycines and to survey on seed contamination in 36 soybean cultivars of Korea. And we have to compare PCR assay with dilution-plating assay of detection and identification. We confirmed detection of pathogen from artificial infected seeds and natural Infected seeds using PCR assay. This assay gave results similar to a seed-wash dilution plating assay and proved more effective than classical methods. Results of survey on seed contamination by X. axonopodis pv. glycines from 36 cultivar seeds showed that the pathogen was detected from Pungsan-namulkong, Mallikong, Taekwangkong, Daemangkong, Ajukkarikong using PCR assay. Therefore, The PCR assay provides a sensitive, rapid tool for the specific detection of X. axonopodis pv. glycines in soybean seeds.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.11
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• pp.1770-1776
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• 2007

Beef carcasses were examined to explore the effects of spinal cord removal and washing on central nervous system tissue (CNST) decontamination of the surface during the slaughtering process. A total of 15 carcasses were split by sawing centrally down the vertebral column and left sides of split carcasses were used for analysis. Samples were collected by swabbing the surface from 4 defined parts on the interior and 4 on the exterior of carcasses from the abattoir and analyzed using an ELISA-based test. The results showed that automatic and manual spray washing decreased CNST contamination, especially on the interior ventral parts of carcass surfaces (p<0.01), but did not decrease CNST on the interior dorsal parts. Increasing washing time to 60 s did not affect the reduction of CNST contamination. Samples following spinal cord removal prior to splitting showed lower calculated levels of "risk material" than the stated limit of detection (0.1%) of the ELISA kit on interior and exterior carcass parts (p<0.01). Therefore, spinal cord removal prior to splitting could be a very effective way to minimize CNST contamination of beef carcasses.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.842-848
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• 2009

The purpose of this study was to determine the extent of domoic acid (DA) a potent neurotoxin, responsible for the syndrome amnesic shellfish poisoning (ASP) contamination of various species of bivalve shellfish purchased from fish market in Korea and the implications for food safety. Liquid chromatography (LC) methods were applied to quantify DA in shellfish after sample clean-up using solid-phase extraction (SPE) with strong anion exchange (SAX) cartridges. Toxin detection was achieved using photodiode array ultraviolet (LC-UV) and electrospray ionization-mass (LC-ESI-MS). DA was identified in 4 bivalve shellfishes of 872 shellfishes collected from March, 2006 to October, 2007 in Korea. DA amount of 3 surf clams (Mactra veneriformis) collected at Seoul, Daejeon, and Daegu were 4.13, 1.99, and 1.94 mg/kg, respectively. DA amount of 1 pink butterfly shell (Peronidia venulosa) collected at Seoul was 3.02 mg DA/kg. The amounts of DA that were present in 4 bivalve shellfishes were within EU guideline limits for sale of shellfish (20 mg DA/kg).