• Title/Summary/Keyword: contamination materials

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Quantitative Microbial Risk Assessment of Non-thermal Processed Japanese Foods Using Monte Carlo Simulation (몬테카를로 시뮬레이션을 이용한 일식메뉴 중 비가열 처리 식품의 정량적 위해평가)

  • Song, Ju-Hyun;Choi, Yu-Jin;Nang, Hyo-Min;Lee, Kwang-Geun
    • Food Engineering Progress
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    • v.13 no.1
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    • pp.56-63
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    • 2009
  • The aim of this study was to control the outbreak of food pathogen through quantitative microbial risk assessment (QMRA). We used Monte Calro Simulation (MCS) to predict contamination levels of Staphylococcus aureus on the raw materials, equipments and cook in Japanese restaurant located in Seoul. The result of sensitivity analysis showed that the most significant factor for the outbreak of food pathogen was consumption temperature and storage time. In shrimp and octopus sushi, 'consumption temperature' was the highest sensitivity value of 0.419 followed by 'storage time' of 0.374. To increase safety of sushi, consumers should have sushi as soon as possible after cooking. In sushi 'storage time after cooking' was determined as Critical Control Point (CCP). To determine Control Limit (CL), Scenario Analysis (SA) was carried out. In sushi, SA was carried out using storage time as a unit condition. Safety level of S. aureus was set lower than 5 log CFU/g. After 2 hr 'storage time' the number of S. aureus increased to 3.908 log CFU/g. Therefore, 'storage time' of sushi was set as CL in case of room temperature storage.

Application of Antimicrobial Peptides against Microcystis aeruginosa to Control Harmful Algal Blooms (항균 펩타이드를 이용한 녹조현상 원인종 Microcystis aeruginosa의 제어)

  • Han, Sang-Il;Park, Yoonkyung;Choi, Yoon-E
    • Korean Journal of Environmental Biology
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    • v.36 no.4
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    • pp.601-609
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    • 2018
  • Microcystis aeruginosa, a freshwater cyanobacteria species known to be one of the most predominant species responsible for cyanobacterial harmful algal blooms (CyanoHABs). It has been frequently associated with the contamination of neurotoxins and peptide hepatotoxins, such as microcystin and lipopolysaccharides-LPSs. CyanoHABs control technologies so far put in place do not provide a fundamental solution and cause secondary pollution linked with the control measures. For this study, algicidal peptides, which have been reported to be non-toxic and to have antimicrobial properties, were employed for the development of novel eco-friendly control against CyanoHABs. The four peptides (CMA1, CMA2, HPA3P, and HPA3NT3) selected in this study showed significant algicidal effects against M. aeruginosa cells inducing cell aggregation and flotation. Moreover, the newly generated peptides (K160242-5) with certain modifications also displayed high algicidal activity. The algicidal activity of the peptides was found to depend on the concentrations and structures of each of amino acid. The results of this study suggested a novel possibility of CyanoHABs control using the non-toxic algicidal peptides.

Analyzing Characteristic of Deterioration Status for Stone Properties in the Tae-Jo Geonwolleung of the Royal Tombs of the Joseon Dynasty (조선왕릉 태조 건원릉 내 석물의 훼손 특성 분석)

  • Lee, Mi Hye;Lee, Myeong Seong;Chun, Yu Gun;Lee, Tae Jong
    • Korean Journal of Heritage: History & Science
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    • v.48 no.4
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    • pp.62-73
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    • 2015
  • The Tae-Jo Geonwolleung is the tomb of the first king Tae-Jo of the Joseon Dynasty in the complex of the Royal Tombs of the Joseon Dynasty which is listed in World Heritage, and it contains various types of stone properties. The material of the stone properties consist of a single type of medium-grained biotite granite, however, each properties have different intensity and types in deterioration phenomena according to their locations and purposes. The major deterioration types of the stones are analyzed as physical decomposition and biodeterioration. The exfoliation, breaking-out and granular decomposition are widespread types of the deterioration throughout the entire burial mound stone properties and surrounding stone properties. On the other hands, the colonization of mosses and plants, and contamination by foreign materials are found more frequent in the burial mound stone properties as these stones are in contact with the soil of the tomb mound and moisture in the soil helped biodeterioration. It is suggested that anti-biology treatment and physical reinforcement are applied to the deteriorated stones to prevent further damage on the stone components of the tomb.

Geochemical Studies of BIF in Wugang, North China Craton: Implication for the Genesis (북중국 우강 지역에 분포하는 호상철광상의 성인에 대한 지구화학적 연구)

  • Moon, Inkyeong;Lee, Insung;Yang, Xiaoyong
    • Economic and Environmental Geology
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    • v.52 no.3
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    • pp.213-221
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    • 2019
  • The Wugang banded iron formation (BIF) is located within the Taihua complex at the southern margin of the North China Craton (NCC). In this study, we analyzed major elements and rare-earth elements in iron ores from the Wugang BIF, to study the type of BIFs and their formation mechanism in combination with previously-published data from the literature. We found that the iron ores from the Wugang BIF display two types of banding textures, which can be described as weak banding or no banding. The samples are composed of coarse-grained magnetite, quartz, pyroxene, and amphibole. Based on our geochemical results, mixing of a hydrothermal fluid with sea water led to the precipitation of the Wugang BIF, and there is evidence of crustal contamination. These results, combined with previous literature data, almost all of the iron ores lack Ce anomalies, though some samples show negative Ce anomalies. Our results indicate that the Wugang BIF was formed in a dominantly reducing environment, although the surfaces were relatively oxidized. Geochemical evidence suggests that the Wugang BIF iron ores were formed in a near-shore continental-shelf environment or in a back-arc basin. The BIF is known as interbedded with migmatite, amphibole gneiss, minor quartz and marble, which indicating lack of volcanic materials input. This study, combined with previous results on geochemical interpretation of related wall rock of Wugang BIF, demonstrated that Wugang BIF belongs to Superior-type BIF.

Research of Monitoring of Conservation Condition and Investigation Method of National Designated Heritage - Focusing on Regular Monitoring of National Designated Movable Cultural Heritage - (국가지정 지류문화재의 보존현황 파악 및 조사방안 연구 - 국가지정 동산문화재 정기조사를 중심으로 -)

  • Jeong, Seon-Hwa;Park, Sang-Kyu
    • Korean Journal of Heritage: History & Science
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    • v.49 no.4
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    • pp.196-217
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    • 2016
  • This study was conducted to identify the state of conservation of the national paper heritages and to seek ways of conservation management, focusing on regular monitoring directly performed by the government on the national movable cultural heritages. Subjects for the investigation were limited to investigations conducted by both the Cultural Heritage Conservation Center and the Artistic Heritage Division in 2014 and 2015. Paper heritages are easily affected by temperature, humidity, lighting, etc. due to the nature of the material and can easily be damaged by physical strength; therefore stable conservation environment is essential and regular investigation on movable cultural heritages conducted according to the Cultural Heritage Protection Act is necessary to protect from contamination, being torn, bending, friction, or loss. Losing a chance for timely proper treatment will bring irrevocable result therefore strict management is necessary; continuous monitoring is also needed after treatment. Analysis on the pigments, materials and structures, detailed investigation, data establishment for conservation of cultural heritages and regular investigation should be done. Detailed data on the national cultural heritages will be a base of more reasonable conservation management system for the national paper heritages and will realize continuous improvement on regular investigation practice.

Tetanus occurred by misuse of syringe in Korean native cattle (한우에서의 주사기 오사용으로 발생한 파상풍 증례)

  • Lee, KyungHyun;Kim, HaYoung;Jung, ByeongYeal;Kim, JongWan;Lee, KiChan;So, ByungJae;Oem, JaeGu;Song, JaeChan;Choi, Eun-Jin
    • Korean Journal of Veterinary Service
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    • v.42 no.1
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    • pp.39-42
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    • 2019
  • Tetanus is an acute, often fatal, and infectious disease of all species of domestic animals caused by the neurotoxin of Clostridium tetani (C. tetani). This disease is usually known to develop after microbial contamination in the deep or penetrating wound sites. In February 2017, a farmer who was raising 76 cows injected foot and mouth disease vaccine to three or more cows with one syringe. Their clinical symptoms were observed 2 to 16 days after the vaccination. The initial symptoms were stiffness, rigidity of the neck and limbs, pricked ears, and prolapse of the third eyelid. Subsequently, there was recumbency with extension of the limbs, convulsions and opistotonus and the affected 20 cows were all died. Two dead cows were submitted to Animal and Plant Quarantine Agency for disease diagnosis. At necropsy, a focal edematous abscess of 15 to 20 cm in diameter was grossly observed in the subcutaneous and intramuscular tissue of scapular region and filled with a large amount of greenish pus. The feed was full in oral cavity and slightly observed in the trachea and lobes of lung. Histopathologically, focal granulomatous nodules with eosinophilic materials in the tissue were observed. In the lung, aspiration pneumonia and gram (+) bacteria were seen. The C. tetani was isolated in samples anaerobically cultured using reinforced clostridial medium and identified by PCR. To our knowledge, no previous outbreak of tetanus in cattle has affected such a high number of animals; neither has it been associated with misuse of the same syringe and needle to administer multiple individuals.

The Roles of Lactic Acid Bacteria for Control of Fungal Growth and Mycotoxins (곰팡이 생육 및 곰팡이 독소 생산의 억제에 있어서의 유산균의 역할)

  • Kim, Jihoo;Lee, Heeseob
    • Journal of Life Science
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    • v.30 no.12
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    • pp.1128-1139
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    • 2020
  • Over recent years, it has become evident that food and agricultural products are easily contaminated by fungi of Aspergillus, Fusarium, and Penicillium due to rapid climate change, which is not only a global food quality concern but also a serious health concern. Owing to consumers' interest in health, resistance to preservatives such as propionic acid and sorbic acid (which have been used in the past) is increasing, so it is necessary to develop a substitute from natural materials. In this review, the role of lactic acid bacteria as a biological method for controlling the growth and toxin production of fungi was examined. According to recent studies, lactic acid bacteria effectively inhibit the growth of fungi through various metabolites such as organic acids with low molecular weight, reuterin, proteinaceous compounds, hydroxy fatty acids, and phenol compounds. Lactic acid bacteria effectively reduced mycotoxin production by fungi via adsorption of mycotoxin with lactic acid bacteria cell surface components, degradation of fungal mycotoxin, and inhibition of mycotoxin production. Lactic acid bacteria could be regarded as a potential anti-fungal and anti-mycotoxigenic material in the prevention of fungal contamination of food and agricultural products because lactic acid bacteria produce various kinds of potent metabolic compounds with anti-fungal activities.

Standardization and HPTLC Fingerprinting of a Polyherbal Unani Formulation

  • Beg, Mirza Belal;Viquar, Uzma;Naikodi, Mohammad Abdul Rasheed;Suhail, Habiba;Kazmi, Munawwar Husain
    • CELLMED
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    • v.11 no.1
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    • pp.4.1-4.8
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    • 2021
  • Background: The Unani system of medicine has been practised since centuries for the treatment of a range of diseases. In spite of their efficacy they have been widely criticised due to the lack of standardization and poor quality control. Standardization of Unani medicine is a valuable issue at the present because they are very prone to contamination, deterioration, adulteration and variation in composition due to biodiversity as well as careless collection. Objective: To Standardize and Development of HPTLC Fingerprinting of a polyherbal Unani formulation Qurs-e-Safa. Materials and methods: The conventional and modern analytical techniques were used to standardise Qurs-e-Safa. The study was carried into three different batches of Qurs-e-Safa prepared with its ingredients. The parameters studied are organoleptic, microscopic, physicochemical parameters, phytochemical screening, TLC, HPTLC profile, aflatoxin, microbial load and heavy metal analysis. Results and conclusion: Qurṣ-e-Sa'fa is dark yellow in colour and aromatic smell. Uniformity of diameter and weight variation were found to be 13 ± 0, and 524.7 ± 1.72 mg. friability, hardness and disintegration time of all 3 batches were found to be (0.0615 ± 0.004, 0.0885 ± 0.0047 and 0.0725 ± 0.0058), (3.5 ± 0.2886, 3.67 ± 0.1674 and 3.67 ± 0.1674) and (16 to 17 minutes). Extractive value were found to be maximum in distilled water (38.488 ± 0.20, 37.3824 ± 0.38 and 39.8177 ± 0.13) followed by alcohol (27.5406 ± 0.54, 27.5656 ± 0.32 and 26.9229 ± 0.25). Loss of weight on drying, pH, total ash, acid insoluble ash, qualitative test was set in. Phytochemical screening revealed the presence of Carbohydrates, Phenols, Resins, Proteins, Steroids, fixed oil and Flavonoids. The microbial load was found absent and heavy metals were within permissible limits. The data evolved from the study may serve as a reference to validate and also help in the quality control of other finished products in future research.

Risk Assessment of Arsenic-Contaminated Groundwater in Multiple Scenarios in a Rural Area of Gyeongnam Province, Korea (경남 농촌 지역 비소 오염 지하수의 시나리오별 위해성 평가)

  • Oh, Serim;Lee, Jin-Yong;Moon, Sang-Ho;Jang, Jiwook;Jeong, Eunju
    • The Journal of Engineering Geology
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    • v.32 no.4
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    • pp.437-448
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    • 2022
  • This work aims to assess the threat to human health of hazardous materials in groundwater that is used domestically and for drinking. Two distinct sub-assessments are considered: cancer and non-cancer risk. The studied groundwater is in an agricultural area of Gyeongnam Province, Korea, and is contaminated by arsenic at a mean level of 16.27 ㎍/L, far greater than the WHO guideline (10 ㎍/L for drinking water). We collected groundwater data from the National Groundwater Information Center (gims.go.kr) and assessed the risk to human health following the methodology of the United States Environmental Protection Agency. We considered three exposure scenarios: domestic use (scenario 1) and drinking use with different doses (scenarios 2 and 3). Scenario 1 had a median hazard quotient (HQ) of 0.77 and a cancer risk (CR) of 0.013. Scenario 2 had a median HQ of 0.08 and a CR of 3.69 × 10-5, and the values for scenario 3 were 0.11 and 4.82 × 10-5, respectively. Scenario 1 is likely the most hazardous to human health. Further study of the origin of arsenic in groundwater in the study area is required, as are remedial measures to mitigate its health effects.

Evaluation of Environmental Stability and Durability of Cementitious Mixed Soil (시멘트계 혼합토의 환경안정성 및 내구성 평가)

  • Oh, Sewook;Bae, Wooseok;Kim, Hongseok
    • Journal of the Korean GEO-environmental Society
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    • v.23 no.9
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    • pp.17-23
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    • 2022
  • Using cement as a road subbase is economical, easily modified and supplemented and has excellent road pavement quality control. In addition, cement adheres well to sandy soils without adhesion, and it plays a role of permanently preserving adhesion in viscous soils with adhesion, so it can be widely applied as stable treatment with the advantages of increased strength, reduced compressibility. and improved durability. However, while cement is excellent in terms of strength for a road subbase, the material properties mean that it is difficult to maintain and reinforce when cracks or fractures occur due to dry shrinkage, and the pH increases in the ground due to hexavalent chromium eluting from cement. which can cause environmental problems such as groundwater contamination. Therefore, this study evaluates the usability of alternatives in the road base layer such as environmentally cementitious stabilizer and on-site soil generated from the site. We intend to reduce the environmental damage and evaluate the durability. To evaluate the applicability of the site, Environmental stability test and freeze-thaw test and wetting-drying test was conducted to evaluate the strength characteristics of alternative materials on the road through the limited performance evaluation of environmentally cementitious stabilizer. The test ranges were set at mixing ratios of 10%, 20%, and 30% and ages of three days, and 28 days old to evaluate the early strength and reference strength according to the mixing ratio of the environmentally cementitious stabilizer.