• Journal of Microbiology and Biotechnology
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• 제28권7호
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• pp.1209-1216
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• 2018

This study aimed to evaluate the antimicrobial activity of 2-phenylethynyl-butyltellurium (PEBT) in Escherichia coli and the relation to its pro-oxidant effect. For this, we carried out the disk diffusion test, minimum inhibitory concentration (MIC) assay, and survival curve analysis. We also measured the level of extracellular reactive oxygen species (ROS), activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), and level of non-protein thiols (NPSH). PEBT at 1.28 and 0.128 mg/disk exhibited antimicrobial capability in the disk diffusion test, with an MIC value of 1.92 mg/ml, whereas PEBT at 0.96, 1.92, and 3.84 mg/ml inhibited bacterial growth after a 9-h exposure. PEBT at 3.84, 1.92, and 0.96 mg/ml increased extracellular ROS production, decreased the intracellular NPSH level, and reduced the SOD and CAT activities. Glutathione or ascorbic acid in the medium protected the bacterial cells from the antimicrobial effect of PEBT. In conclusion, PEBT exhibited antimicrobial activity against E. coli, involving the generation of ROS, oxidation of NPSH, and reduction of the antioxidant defenses in the bacterial cells.

• Bulletin of the Korean Chemical Society
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• 제14권3호
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• pp.317-318
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• 1993

• International Journal of Computer Science & Network Security
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• 제23권1호
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• pp.120-124
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• 2023

Strong surface waves among collinearly arranged patch antenna arrays pose unwanted inter element coupling particularly when high permittivity dielectric materials are used. In order to avert those waves, a novel Defected Ground Structure (DGS) is carved out systematically between two E-plane patch antenna elements. The introduced low profile μ shaped structure consequently improves impedance bandwidth and reflection coefficient by suppressing surface waves considerably. Parametric simulation results are analyzed and discussed.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.552-553
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• 2006

The present study investigates the behavior of the sintering and hardness of stainless steel samples reinforced with NbC and TaC. Matrixes of pure stainless steel were compacted with addition of up to 3% wt NbC or TaC in a cylindrical die of steel $(\phi\;=\;5,0\;mm)$ at 700 MPa and sintered in an electrical resistance furnace under argon atmosphere. The sintered samples were characterized by density and hardness measurement, optical microscopy and scanning electron microscopy (SEM). The preliminary results show that the size and distribution of carbides influence in the sintering and hardness of the sintered samples.

• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2683-2688
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• 2012

The position of the thermodynamic equilibrium for reverse thermochromic spiropyran 6-carboxylates (SP-COOHs) was easily determined in aqueous binary mixtures, such as water-methanol, water-acetonitrile and water-dimethyl sulfoxide. The existence of more than one type of interconvertible species of the ring-opened form of SP-COOH in aqueous binary solvents enables us to evaluate the molar extinction coefficients of the ring-opened species of SP-COOH and to obtain the thermodynamic parameters.

• Asian-Australasian Journal of Animal Sciences
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• 제12권6호
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• pp.944-950
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• 1999

Hexavalent chromium (CrVI) was fed to one day old chicks of Gallus domesticus in the form of different concentrations (250 and 500 mg/kg feed) of potassium dichromate mixed with the feed, ad libitum, for 32 weeks. After 20 weeks of feeding, the total body weight was higher in the low dose (260 mg/kg (feed) group and lower in the high dose (500 mg/kg feed) group, as compared with the control chicks. After 32 weeks of feeding, however, the total body weight was significantly decreased in both the treated groups. Egg laying was enhanced. Fertility remained unaffected, whereas hatchability was considerably decreased after CrVI-treatment. The egg shell thickness increased significantly (13%). Cr was deposited in a dose dependent manner in the liver and lungs. Some structural derangements in liver were also noted in treated chicks. The results of this study i.e., rapid ageing, excessive Cr deposition, decreased hatchability and hepatotoxicity indicate toxic effects of CrVI.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2023년도 춘계학술발표대회
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• pp.413-414
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• 2023

IT 기술의 발달로 E-Commerce 분야는 실시간으로 발생되는 데이터양이 증가하고 있으며, 발생된 데이터는 개인화 맞춤 서비스에 많이 활용되고 있다. 그러나 신생 E-commerce 기업은 신규 상품 및 기존 상품에 대한 정보와 고객 간의 상호 작용 데이터가 존재하지 않아 콜드 스타트 문제가 발생한다. 이에 본 논문에서는 E-commerce 환경에서 실시간 사용자 구매패턴 분석을 통한 사용자 상품 추천 시스템을 제안한다. 제안하는 시스템은 Kafka와 Spark를 사용해 실시간 스트림을 데이터를 처리한다. 주요 기능은 ALS 알고리즘과, FP-Growth 알고리즘을 적용해 콜트 스타트 문제를 해결하며, 사용자 구매 패턴 분석을 통한 분석 결과에 맞는 상품을 사용자에게 추천한다.

• Bulletin of the Korean Chemical Society
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• 제8권4호
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• pp.235-237
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• 1987

(7Z, 11E)-7, 11-Hexadecadien-1-yl acetate(1), the sex pheromone of the female Angoumois grain moth, Sitotroga cerealella, was synthesized via the acetylenic intermediate, (11E)-11-hexadecen-7-yn-ol THP ether(2). The acetylenic compound was prepared from 7-octyn-1-ol THP ether(4) and (3E)-1-bromo-3-octene(3). The (E)-homoallylic bromide 3 was synthesized by the Julia olefin synthesis of 1-cyclopropylpentan-1-ol(6).

• Toxicological Research
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• 제24권4호
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• pp.253-261
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• 2008

Allergic asthma is a worldwide public health problem and a major socioeconomic burden disease. It is a chronic inflammatory disease marked by airway eosinophilia and goblet cell hyperplasia with mucus hypersecretion. Mouse models have proven as a valuable tool for studying human asthma. In the present report we describe a comparison of mouse asthma models. The experiments were designed as follows: Group I was injected with ovalbumin (OVA, i.p.) on day 1 and challenged with 1% OVA (aerosol exposure) on days $14{\sim}21$. Group II was injected on day 1, 14 and aerosol-immunized on days $14{\sim}21$. Group III was injected on day 1, 14 and immunized by 1% OVA aerosol on days $18{\sim}21$. We assessed asthma induction by determining the total number of white blood cells (WBC) and eosinophils as well as by measuring cytokine levels in bronchoalveolar lavage fluid (BALF). In addition, we evaluated the histopathological changes of the lungs and determined the concentration of immunoglobulin E (IgE) in serum. Total WBC, eosinophils, Th2 cytokines (IL-4, IL-13) and IgE were significantly increased in group I relative to the other groups. Moreover, histopathological studies show that group I mice show an increase in the infiltration of inflammatory cell-in peribronchial and perivascular areas as well as an overall increase in the number of mucus-containing goblet cells relative to other groups. These data suggest that group I can be a useful model for the study of human asthma pathobiology and the evaluation of existing and novel therapeutic agents.

• 산업융합연구
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• 제17권3호
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• pp.39-49
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• 2019

ICT의 발전에 따라 대학교육의 새로운 패러다임이 요구되고 있다. 이에 따른 스마트 캠퍼스 구축은 대학 교육의 패러다임을 바꾸는 학습과 지식 중심의 접근을 비롯하여 혁신적인 기술의 적용, 여러 이해관계자의 니즈를 반영하는 접근 등 다양한 관점에서 효율적인 시스템 구축을 시도해야 한다. 본 연구는 스마트 캠퍼스 생태계를 위한 플랫폼 구축에 관한 연구로서 스마트 캠퍼스의 다양한 이해관계자의 니즈를 반영하는 접근을 하였으며, 이 중에 가장 중요한 대학생 사용자들의 학습과 대학생활 및 사회연결을 축으로 하여 이들의 경쟁력 강화와 사회진출을 돕기 위한 기능에 초점을 맞추는 연구를 하였다. 먼저, 선행연구고찰을 통해 스마트 캠퍼스 구축관련 이론들을 살펴보았으며, 다음으로는 국내외 환경분석과 동향분석을 통하여 대학생 핵심역량개발과 취업지원을 중심으로 하는 e-포트폴리오와 산학협력 지원 시스템에 대해 목표모델을 설계하여 제시하였으며, 지속적인 스마트 캠퍼스 발전 모델을 위한 주안점을 제안하였다.