• 한국포장학회지
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• 제13권2호
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• pp.75-78
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• 2007

Regulation of food packaging in Korea, Eurpoe and USA are surveyed. Food packaging manufacturer or converter has a responsibility to evaluate the safety of migration of harmful materials from typical finished packaging items. The 'overall migration limit' of all components from the packaging and 'specific migration limits(SML)' of monomers or additives are evaluated with food simulants, water, acetic acid, ethanol and n-heptane, based on the regulations of the countries. A substance not regulated has to be authorized with the technical data required, information on chemical identity, physical chemical and other properties, the intended use, migration studies and toxicological studies.

• 한국식품위생안전성학회지
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• 제27권4호
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• pp.325-331
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• 2012

Food allergy refers to an immunologically mediated adverse reaction to food, mainly to proteinaceous constituents. Health implications vary between those individuals who experience mild physical discomforts to those with fast-acting, life-threatening anaphylactic reactions. The prevalence of food allergy is higher in children than in adults, estimated around 4-8% and 1-2% respectively in developed countries. Food allergy has no effective cure at the present time and total avoidance of causative foods is the most reliable prophylactic method currently recommended by the medical community. To help food allergic patients to make informed choices of their foods, mandatory labeling of selected food allergens has been introduced in several countries. All food allergen labelling provisions specify a set of allergens common to the regulated countries. Policy divergence, however, exists between countries by inclusion of additional allergens unique to specific countries and enforcement of specific labelling requirements. Such variations in food allergen labelling regulations make it difficult to manage allergen labeling in imported pre-packaged food products. This paper addresses two current issues in food allergen regulation: 1) an urgent need to determine true prevalence of food allergy in the Asia-Pacific region. This will enable refinement to the food allergen regulation to be more country-specific rather than simply adopting CODEX recommendations. 2) There is an urgent need for harmonization of food allergen regulation in order to prevent food allergen regulation becoming a trade barrier.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1995년도 제3회 추계심포지움
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• pp.29-35
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• 1995

• BMB Reports
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• 제43권6호
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• pp.419-426
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• 2010

Aeromonas hydrophila is a bacterial pathogen that infects a large number of eukaryotes, including humans. The UDP-galactose 4'-epimerase (GalE) catalyzes interconversion of UDP-galactose to UDP-glucose and plays a key role in lipopolysaccharide biosynthesis. This makes it an important virulence determinant, and therefore a potential drug target. Our earlier studies revealed that unlike other GalEs, GalE of A. hydrophila exists as a monomer. This uniqueness necessitated elucidation of its structure and active site. Chemical modification of the 6xHis-rGalE demonstrated the role of histidine residue in catalysis and that it did not constitute the substrate binding pocket. Loss of the 6xHis-rGalE activity and coenzyme fluorescence with thiol modifying reagents established the role of two distinct vicinal thiols in catalysis. Chemical modification studies revealed arginine to be essential for catalysis. Site-directed mutagenesis indicated Tyr149 and Lys153 to be involved in catalysis. Use of glycerol as a cosolvent enhanced the GalE thermostability significantly.

• Asian Pacific Journal of Cancer Prevention
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• 제16권17호
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• pp.7393-7400
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• 2015

Matrix metalloproteinase (MMP) 9, a key member of multifunctional family of zinc dependent endopeptidases has been found to be upregulated during inflammation and in some cancers. MMPs cleave extracellular matrix (ECM) proteins and play critical roles in cellular apoptosis, angiogenesis, tumor growth and metastasis. Several genetic polymorphisms have been identified that show allele specific effects on MMP9 regulation and are associated with gastric cancer, the fourth most common malignancy in the world. Besides Helicobacter pylori infection, genetic predisposition is another documented risk factor for gastric carcinoma. The single nucleotide polymorphism (SNP) at position -1562C/T of MMP9 results in the modulation for binding of transcription factors to the MMP9 gene promoter and thereby causes differences in protein expression and enzymatic activity. MMP9 transcriptional regulation during gastric cancer development remains poorly known although several studies have demonstrated associations between MMP9 -1562 C/T polymorphism with different diseases. Knowledge on mechanisms of MMP9 upregulation during gastric cancer may provide new paradigm in diagnostics and therapeutics.

• Current Applied Physics
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• 제18권11호
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• pp.1300-1305
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• 2018

The tunable electronic performance of the solution-processed semiconductor metal oxide is of great significance for the printing electronics. In current work, transparent thin-film transistors (TFTs) with indium-zinc oxide (IZO) were fabricated as active layer by a simple eco-friendly aqueous route. The aqueous precursor solution is composed of water without any other organic additives and the IZO films are amorphous revealed by the X-ray diffraction (XRD). With systematic studies of atomic force microscopy (AFM), X-ray photoemission spectroscopy (XPS) and the semiconductor property characterizations, it was revealed that the electrical performance of the IZO TFTs is dependent on the concentration of precursor solution. As well, the optimum preparation process was obtained. The concentrations induced the regulation of the electronic performance was clearly demonstrated with a proposed mechanism. The results are expected to be beneficial for development of solution-processed metal oxide TFTs.

• Safety and Health at Work
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• 제11권2호
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• pp.193-198
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• 2020

Background: Medical laboratory workers are frequently exposed to a wide range of chemicals. This exposure can have adverse effects on their health. Furthermore, a knowledge lack of the chemical risk increases the likelihood of exposure. The chemical risk assessment reduces the risk of exposure to hazardous chemicals and therefore, guarantees health and safety of the workers. Method: The chemical risk assessment was conducted using a modified INRS method, according to the new CLP Regulation, of 11 unit laboratories in a Moroccan medical laboratory. Observation of each workstation and analysis of safety data sheets are key tools in this study. Results: A total of 144 substances and reagents that could affect the health of the analytical technicians were identified. Among these products, 17% are concerned by the low priority risk score, with 55% concerned by the average priority risk score and 28% concerned by the high priority risk score. This study also enabled to better identify the chemical agents that have restrictive occupational exposure limit value and controls were conducted to this effect. On the basis of the results obtained, several corrective and preventive measures have been proposed and implemented. Conclusion: Risk assessment is essential to ensure the health and safety of workers and to meet regulatory requirements. It enables to identify all the risky manipulations and to adopt appropriate preventive measures. However, it is not a one-time activity but it must be continuous in order to master the changes and thus ensure the best safety of all.

• 대한화학회지
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• 제64권6호
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• pp.360-370
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• 2020

이 연구에서는 증강현실을 활용한 소집단 학습에서 개념 이해 및 몰입, 상황 흥미를 촉진할 수 있는 학습 환경을 학생들의 자기조절 수준에 따라 탐색하였다. 서울시에 소재한 남녀공학 고등학교 1학년 95명이 연구에 참여하였다. 한 모둠에 마커와 스마트 기기를 각각 1개(1-1), 2개(2-2) 또는 4개(4-4)를 제공하는 세 가지 학습 환경을 구성하고, 학생들을 4인 1모둠으로 편성하여 각 학습 환경에 무선 배치하였다. 통합과학 교과의 화학 결합 개념에 대하여 증강현실을 활용한 소집단 학습을 2차시 동안 실시하였다. 이원 변량 분석 결과, 개념 이해도 검사에서는 4-4 학습 환경의 점수가 1-1 또는 2-2 학습 환경보다 유의미하게 높았으며, 자기조절 수준이 낮은 학생들이 학습 환경 변화의 영향을 받았다. 몰입감 검사에서는 4-4 학습 환경의 점수가 1-1 학습 환경보다 유의미하게 높았고, 자기조절 수준이 높은 학생들이 학습 환경 변화의 영향을 받았다. 상황 흥미 검사에서 4-4 및 2-2 학습 환경의 점수는 1-1 학습 환경보다 통계적으로 유의미하게 높았고, 학습 환경 변화는 자기조절 수준 높은 학생과 낮은 학생 모두에게 영향을 주었다. 연구 결과를 바탕으로 증강현실을 활용한 소집단 학습에서 학생들의 개념 이해 및 몰입, 상황 흥미를 촉진할 수 있는 학습 환경에 대한 교육적 함의를 논의하였다.

• 미생물과산업
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• 제12권2호
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• pp.30-35
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• 1986

Almost all of the aerobic organisms contain citric acid cycle (or, tricarboxylic acid cycle). This cycle is involved both in energy metabolism and biosynthetic reactions; generation of NADH which derives the synthesis of chemical energy, ATP, and provision of intermediates needed for the biosynthesis. Because of its importance in the cellular metabolism, the regulation of the TCA cycle and its component enzymes has been extensively studied by many biologists (7,28). Citrate synthase is resposible for the initial step of the cycle and has been recognized as the rate limiting step (14,121,26). Understanding of the mechanism of the expression of citrate synthase should be a key step for the elucidation of the regulation of the TCA cycle in the cell metabolism.

• 한국포장학회지
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• 제14권2호
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• pp.53-56
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• 2008

Polyvinylchloride(PVC) is variously used to produce food packaging, wrap film, sealing compound of drinking bottle cap. Safety of these PVC food package is controlled by Food Code, PVC regulation. This study was carried out researches on manufacture process, physical, chemical properties and monomer(CAS No., common name, molecular structure) of PVC to help the understanding of PVC material. Also, this study helps us the understanding of regulation through researches on the foundation of PVC regulation, the purpose of test and the comment of test method. It is considered that these informations of material properties and explanations of test method are very useful to PVC producers, users and analyzers of them.