• Journal of Electrochemical Science and Technology
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• 제4권1호
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• pp.41-45
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• 2013

Platinum is a well known element which shows a significant electrocatalytic activity in many important applications. In glucose sensor, because of the poisoning effect of reaction intermediates and the low surface area, the electrocatalytic activity towards the glucose oxidation is low which cause the low sensitivity. So, we fabricate a nanoporous PtZn alloy electrode by deposition-dissolution method. It provides a high active surface and a large enzyme encapsulating space per unit area when it used for an enzymatic glucose sensor. Glucose oxidase was immobilized on the electrode surface by capping with PEDOT composite and PPDA. The composite and PPDA also can exclude the interference ion such as ascorbic acid and uric acid to improve the selectivity. The surface area was determined by cyclic voltametry method and the surface structure and the element were analyzed by Scanning Electron Microscope (SEM) and Energy Dispersive X-ray spectroscopy (EDX), respectively. The sensitivity is $13.5{\mu}A/mM\;cm^2$. It is a remarkable value with such simply prepared senor has high selectivity.

• 센서학회지
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• 제28권3호
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• pp.139-145
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• 2019

Precautionary detection of chemical warfare agents (CWAs) has been an important global issue mainly owing to their toxicity. To achieve proper detection, many studies have been conducted to develop sensitive gas sensors for CWAs. In particular, metal-oxide semi-conductors (MOS) have been investigated as promising sensing materials owing to their abundance in nature and excellent sensitivity. In this review, we mainly focus on various MOS-based gas sensors that have been fabricated for the detection of two specific CWA simulants, 2-chloroethyl ethyl sulfide (2-CEES) and dimethyl methyl phosphonate (DMMP), which are simulants of sulfur mustard and sarin, respectively. In the case of 2-CEES, we mainly discuss $CdSnO_3-$ and ZnO-based sensors and their reaction mechanisms. In addition, a method to improve the selectivity of ZnO-based sensors is mentioned. Various sensors and their sensing mechanisms have been introduced for the detection of DMMP. As the reaction with DMMP may directly affect the sensing properties of MOS, this paper includes previous studies on its poisoning effect. Finally, promising sensing materials for both gases are proposed.

• Mass Spectrometry Letters
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• 제12권3호
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• pp.112-117
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• 2021

α-Amanitin and β-amanitin are highly toxic bicyclic octapeptides responsible for the poisoning of poisonous mushrooms such as Amanita, Galerina, and Lepiota by inhibiting RNA polymerase II, DNA transcription, and protein synthesis. A sensitive, simple, and selective liquid chromatography-high resolution mass spectrometric method using parallel reaction monitoring mode was developed and validated for the simultaneous determination of α- and β-amanitin in mouse plasma to evaluate the toxicokinetics of α- and β-amanitin in mice. Protein precipitation of 5 μL mouse plasma sample with methanol as sample clean-up procedure and use of negative electrospray ionization resulted in better sensitivity and less matrix effect. The calibration curves for α- and β-amanitin in mouse plasma were linear over the range of 0.5-500 ng/mL. The intra- and inter-day coefficient of variations and accuracies for α- and β-amanitin at four quality control concentrations were 3.1-14.6% and 92.5-115.0%, respectively. The present method was successfully applied to the toxicokinetic study of α- and β-amanitin after an oral administration of α- and β-amanitin at 1.5 mg/kg dose to male ICR mice.

• 한국식품영양학회지
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• 제36권5호
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• pp.354-359
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• 2023

A mono-type glycerine fatty acid ester compound was chemically synthesized using medium-chain fatty acids with antibacterial activity, and the physicochemical quality and antibacterial activity of the synthesized glycerine medium-chain fatty acid ester compound were measured. At a reaction molar ratio of MCT(medium chain triglyceride) to glycerine of 1:2.5, 48.15% mono ester was produced. The physicochemical analysis of the synthesized glycerine fatty acid ester compound showed an acid content of 0.38~0.60%, which tended to increase slightly as the glycerine molar ratio increased. The saponification value decreased as the synthesized molar ratio of glycerine increased from 218 to 284. The number of bacteria was measured to confirm the degree of antibacterial activity of glycerine medium-chain fatty acid esters against food poisoning bacteria, Bacillus cereus and Salmonella typhi. The number of bacteria significantly decreased as the MCT:glycerine molar ratio increased. In particular, the antibacterial effect between the treatment groups was the highest when at an MCT:glycerine molar ratio of 1:2.5.

• 한국광물학회지
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• 제12권1호
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• pp.43-53
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• 1999

The medical mineral menas a single mineral or a complex of minerals. It is natural material. using the medical action of he major or the minor elements, and traditional medicine stuff which has been used since long time ago. Jusa, cinnabar as the mineral name, is the product of the hydrothermal process. It is used to relax the body and cure high blood pressure, apoplexy and cardiopathy. Jusais the major component of "An shin hwan" and "Woo hwang chung shim hwan" nowadays because it has such an excellent calm effect. In addition, it is used to cure cancers such as esophageal cancer and gastric cancer. Jusa composed of mercuric sulfide causes mercury poisoning such as Minamata disease. It is dealt with mineralogical property and chemical composition medical stuff in Korea and China, as well asmercury poisoning and medical action of Jusa in this study. In order to predct accumulation of the interior of the body of the major and minor elements in Jusa, leaching experiment of Jusa by artificial gastric juice was done as well as thermodynamic reaction modelling to know concentration of each species of body fluid. The minor elements of 24 species such as As, Pb, Cd, a and Fe by leaching reaction of Jusa and artificial gastric juice were leached. We can know the fact that as is less than 1 ppm, Hg is less than 25 ppm and Cd and m are not detected. In addition, mercury exists as species of Hg2+, HgCl+, HgCl2, HgCl3-, HgCl42-, HgClOH, HgS(H2S)2, Hg(HS)3-, HgS22-, HgOH and Hg(OH)2 by reaction modelling between Jusa and artificial gastric juice. The concentration of sulfide complexes is 24.2 ppm and that of others is less than 10 ppm. According to increasing pH, the concentration of HgS(H2S)2, Hg(HS)3+, HgS22- and Hg(OH)2 increases, whereas the concentration of HgCl+, HgCl2, HgCl3- and HgCl42- decreases. Therefore, Jusa is very useful for the development of new medicine because it is possible to predict formation of the body species and species accumulation on mercury known as a toxic element and concentration changes of toxicity and efficiency.city and efficiency.

• 한국산학기술학회논문지
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• 제21권4호
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• pp.300-310
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• 2020

본 연구는 남녀중학생을 대상으로 하여 부모의 심리적 통제, SNS중독경향성, 스마트폰 게임중독 간 관계를 살펴보고, 남녀중학생의 외로움이 부모의 심리적 통제와 SNS중독경향성 및 스마트폰 게임중독의 관계를 조절하는지 알아보고자 하였다. 이를 검증하기 위해 A지역 중학교의 남녀청소년 259명을 대상으로(남학생 134명, 여학생 125명) 설문조사를 실시하였다. 연구결과 첫째, 외로움과 SNS중독경향성의 관계에서 남학생의 경우 외로움과 SNS중독경향성이 정적상관을 보인 반면, 여학생의 경우 유의미한 상관을 보이지 않았다. 또한 부모의 심리적 통제와 스마트폰 게임중독의 관계에서 여학생의 경우 부모의 심리적 통제와 스마트폰 게임중독이 정적상관을 보인 반면, 남학생의 경우 부모의 심리적 통제와 스마트폰 게임중독과 유의미한 상관을 보이지 않았다. 둘째, 외로움의 수준에 따른 부모의 심리적 통제와 SNS중독경향성과의 관계가 남녀중학생 모두 유의하게 달라지지 않았다. 셋째, 외로움의 수준에 따라 부모의 심리적 통제와 남녀중학생의 스마트폰 게임중독과의 관계를 살펴본 결과 남자 중학생에게만 조절효과가 있는 것으로 나타났다. 마지막으로 본 연구 결과에 대한 한계점 및 후속연구에 대한 제언을 논하였다.

• 한국식품저장유통학회지
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• 제15권4호
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• pp.568-575
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• 2008

본 연구에서는 가열온도를 달리하여 마늘즙을 열처리한 후 생마늘즙과 열처리 마늘즙의 식중독세균에 대한 항균활성을 조사하였다. 생마늘즙과 $65^{\circ}C$에서 30분간 열처리된 마늘즙은 공시된 모든 균주에 대해 강한 항균활성을 나타내었으나, 가열온도가 높을수록 항균활성이 낮아져 $80^{\circ}C$에서 30분간 열처리된 마늘즙은 항균활성이 크게 저하되었고, $95^{\circ}C$에서 30분간 열처리된 마늘즙은 모든 균주에 대해 항균활성을 보이지 않았다. 생마늘즙은 Bacillus subtilis, Bacillus cereus, Staphylococcus aureus 및 Vibrio parahaemolyticus에 대해 고형분 함량 0.1%의 농도에서, Salmonella typhymurium과 Salmonella enteritidis에 대해서는 고형분 함량 0.2%의 농도에서 생육을 완전히 억제시켜 강한 생육저해효과를 나타내었고, Listeria monocytogenes와 Escherichia coli에 대해서는 고형분 함량 0.8%의 농도에서 생육을 완전히 억제시켜 이 균들은 다른 균들에 비해 마늘즙에 대한 감수성이 상대적으로 낮았다. $65^{\circ}C$로 열처리된 마늘즙은 생마늘즙에 비하여 Bacillus subtilis와 Vibrio parahaemolyticus에 대해 최소저해농도가 0.1%에서 각각 0.2% 및 0.4%의 농도로 다소 높게 나타나 마늘즙을 $65^{\circ}C$에서 30분간 열처리할 경우 일부의 균에 대해 생육저해효과가 다소 저하되었으나, $80^{\circ}C$로 열처리된 마늘즙에서는 생육저해효과가 크게 저하되어 공시된 모든 균주에 대한 최소저해농도가 크게 증가되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제27권8호
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• pp.1082-1087
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• 2014

Thirty-two lambs were distributed in eight treatments under $2{\times}2{\times}2$ factorial experiment to compare the effects of two levels of selenium (0.2 to 5 mg/kg dry matter [DM]), sulphur (0.25% and 0.37%) and copper (8 and 25 mg/kg DM) levels on selenium concentration in liver and serum of lambs. A liver biopsy was done on all animals and blood samples were collected from the jugular vein prior to the beginning of the treatments. The blood was sampled every thirty days and the liver was sampled after 90 days, at the slaughter. Increasing differences were noticed during the data collection period for the serum selenium concentration, and it was found to be 0.667 mg/L in animals fed with 5 mg Se/kg DM and normal sulphur and copper concentrations in their diet. However, a three-way interaction and a reduction of selenium concentration to 0.483 mg/L was verified when increasing copper and sulphur concentration levels to 25 ppm and 0.37% respectively. The liver selenium concentration was also high for diets containing higher selenium concentrations, but the antagonist effect with the increased copper and sulphur levels remained, due to interactions between these minerals. Therefore, for regions where selenium is scarce, increasing its concentration in animal diets can be an interesting option. For regions with higher levels of selenium, the antagonistic effect of interaction between these three minerals should be used by increasing copper and sulphur dietary concentrations, thus preventing possible selenium poisoning.

• Toxicological Research
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• 제17권
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• pp.135-138
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• 2001

Female Wistar rats were randomly divided into 5 groups: Control, received distilled water; Low lead, received 0.5 g/ιlead (as acetate) in drinking water; High lead, received 2.0 g/ιlead; Low lead + Minerals, received 0.5 g/ιlead in drinking water and received minerals (Ca$^{2+}$, 25 mg/kg/day; Fe$^{3+}$, 0.47 mg/ kg/day; Zn$^{2+}$, 0.33 mg/kg/day; Se, 0.83 $\mu\textrm{g}$/kg/day) by gavage; High lead + Minerals, received 2.0 g/ιlead and received the same minerals. Animals exposure to lead was from 10 days before mating till postnatal day 21; and the minerals was administered from the first day of pregnancy and during lactation. No statistical difference was found either in body weights or in blood lead levels between the pups received minerals and those only exposed to lead at the same dose. The developmental and behavioral teratological effects of lead on pups, such as time-lag of eye opening, pinna detachment, fur developing, incisor eruption, ear unfolding, and surface righting were observed in this study; and the minerals decreased the toxicity of lead either in low or in high lead exposure pups. The numbers of step-down were significantly increased in lead exposed animals, and the effect of intervention by the minerals was appeared only in the pups exposed to low lead. The ChAT activity and levels of glutamate and aspartate in hippocampus decreased in treated animals compared to control animals, no effect of intervention by the minerals was found. The results of this study indicate that the applied multi-minerals can alter the outcome of develop-mental lead poisoning in rats.s.s.s.

• 한국가스학회지
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• 제13권1호
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• pp.45-51
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• 2009

본 논문은 국내에 건설된 충전소를 분석 검토하여 수소충전소에 대한 안전성 평가를 실시함으로써 수소충전 소의 안전성에 대한 확인과 충전소 설치 시 필요한 기준마련에 기초자료를 제공하는 것이 궁극적인 목표이다. 안전성 평가 방법으로 FMEA (Failure Mode and Effect Analysis)를 사용하였고, 충전소를 크게 4개의 공정(제조, 압축, 저장, 충전)으로 분류하였다. 또한 각각의 발견된 위험요소에 S (severity), O (occurrence), D (detection)의 점수를 부여하여 이 세 요소의 곱의 값인 RPN (Risk Priority Number)의 수치를 이용하여 위험의 우선순위를 정하고, 이를 바탕으로 시나리오를 생성하였다. 생성한 시나리오를 기반으로 사고피해영향평가 결과 주요한 사고 유형으로 jet fire와 폭발이 나타났고, PSA (pressure swing adsorption) 공정 feed line에서의 누출의 경우 원료물질에 따라 CO가스의 농도가 상이할 수도 있으나, CO가스중독 위험성을 함께 예측되었다.