• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.100.1-100
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• 2003

A dctA gene encoding a protein with identity to a C4-dicarboxylate/H+ was cloned from a beneficial biocontrol bacterium, P. chororaphis O6. Expression of the dctA was induced in minimal medium by several organic acids and was repressed by glucose. Highest expression was observed in early-log cells grown on fumarate and succinate with decline as cells approached late-log phase. The dctA transcript accumulated weakly when cells were grown on malate but strong expression was observed with benzoate. Expression of the dctA transcript was repressed in early-log cells upon addition of glucose to fumarate, but was detected as the cell culture aged. A dctA-deficient mutant of O6, constructed by marker exchange mutagenesis, did not grow on minimal medium containing succinate, benzoate, or fumarate, and growth on malate was delayed. The dctA mutant and wild type grew equally on glucose. The dctA mutant on cucumber roots in sterilized potting soil was colonized at levels comparable to those of the wild type, but induction level of disease resistance by the mutant against target leaf spot disease was decreased. These results may indicate that the dctA is essential for utilization of certain organic acids and its expression is controlled by the availability of sugars. In addition, the dctA is not essenitial for cucumber root colonization, but important for induction of disease resistance.

• 반도체디스플레이기술학회지
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• 제14권3호
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• pp.33-36
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• 2015

It has increased several decades in the field of Indium Tin Oxide (ITO) transparent thin film, However, a major problem with this ITO thin film application is high cost compared with other transparent thin film materials[1]. So far, in order to overcome this disadvantage, we show that a transparent ITO/Ag/i-ZnO multilayer thin film electrode would be more cost-effective and it has not only highly transparent but also conductive properties. The aim of this research has therefore been to try and establish how ITO/Ag/i-ZnO multilayer thin film would be more effective than ITO thin film. Herein, we report the properties of ITO/Ag/i-ZnO multilayer thin film by using optical spectroscopic method and measuring sheet resistance. At a certain total thickness of thin film, sheet resistance of ITO/Ag/i-ZnO multilayer was drastically decreased than ITO layer approximately $40{\Omega}/{\Box}$ at same visible light transmittance. (minimal point $5.2{\Omega}/{\Box}$). Tendency, which shows lowly sheet resistive in a certain transmittance, has been observed, hence, it should be suitable for transparent electrode device.

• 한국미생물·생명공학회지
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• 제47권2호
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• pp.250-258
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• 2019

삼림지역의 고목에서 분리한 Peniophora sp. JS17 균주는 사람 머리카락 유래 멜라닌을 탈색하는 세포 외 분비효소를 생산했다. JS17 균주는 laccase 및 manganese peroxidase 활성을 나타냈지만 lignin peroxidase 활성은 나타내지 않았다. 본 균주를 회분배양한 결과 멜라닌 탈색 활성은 laccase 활성으로부터 유래하는 것으로 확인되었다. Peniophora sp. JS17 균사체로부터 멜라닌 탈색 효소를 생산하기 위한 배지 조건을 조사하였다. 다양한 합성 배지 중에서 minimal medium (2% glucose, 0.2% malt extract, 0.1% $KH_2PO_4$, 0.4% $MgSO_4{\cdot}7H_2O$)이 가장 높은 laccase 활성을 나타내었다. Laccase 생산에 대한 배양 조건을 최적화하기 위하여 minimal medium의 조성 중에서 탄소원 및 질소원에 대한 영향을 조사하였다. 다양한 탄소원 및 질소원 중에서 각각 2% xylose 및 0.4% tryptone의 경우에 가장 높은 laccase 활성을 나타내었다. Ammonium sulfate 침전 및 Hitrap Q Sepharose column을 이용하여 정제한 효소는 SDS-PAGE에서 약 70 kDa의 분자량 부근에 2종류의 isozyme 형태로 존재 하였다. 멜라닌 탈색율은 HBT 및 syringaldehyde의 존재하에서 48시간 만에 각각 77% 및 55%를 나타내었고, mediator가 없는 조건에서는 9%의 멜라닌 탈색율을 나타내었다.

• 대한미생물학회지
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• 제20권1호
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• pp.79-89
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• 1985

It is important to discriminate between tuberculosis and tuberculosis-like disease by Mycobacteria other than tuberculosis in the serodiagnosis of tuberculosis. But because common antigens share among Mycobacteria, their antigenicities to human are similar. Therefore degree of cross-reactivity of antibody in the sera of patients with tuberculosis between M. tuberculosis and Mycobacteria other than tuberculosis should be checked to increase the specificity in the serodiagnosis of tuberculosis. The activity levels of IgG antibody in the sera of 106 patients confirmed as active pulmonary tuberculosis and 30 normal healthy control person to the pressate extract antigen (TE, BE, AE, and FE antigen) from M. tuberculosis, M. bovis, M. avium, and M. fortuitum were measured by enzyme-linked immunosorbent assay and the crossreactivity of IgG antibody with mycobacterial species was analysed. The results were as follows; 1. The activity level(O.D. at 492nm) of IgG to TE antigen in sera of patients with pulmonary tuberculosis was $0.228{\pm}0.167$ in minimal tuberculosis; moderately advanced, $0.556{\pm}0.616$; far advanced, $1.116{\pm}0.651$ and $0.315{\pm}0.245$ in miliary tuberculosis. 2. The activity level (O.D. at 492nm) of IgG to BE antigen in sera of patients with pulmonary tuberculosis was $0.190{\pm}0.162$ in minimal tuberculosis; moderately advanced, $0.337{\pm}0.361$; far advanced, $0.713[\pm}0.460$ and $0.204{\pm}0.162$ in miliary tuberculosis. 3. The activity level (O.D. at 492nm) of IgG to AE antigen in sera of patients with pulmonary tuberculosis was $0.165{\pm}0.114$ in minimal tuberculosis; moderately advanced, $0.392{\pm}0.494$; far advenced, $0.751{\pm}0.512$ and $0.233{\pm}0.191$ in miliary tuberculosis. 4. The activity level (O.D. at 492nm) of IgG to FE antigen in sera of patients with pulmonary tuberculosis was $0.280{\pm}0.227$ in minimal tuberculosis; moderately advanced, $0.460{\pm}0.564$ ; far advanced, $0.845{\pm}0.573$ and $0.257{\pm}0.103$ in miliary tuberculosis. 5. The activity level (O.D. at 492nm) of IgG in sera of healthy control person was $0.126{\pm}0.084$ to TE antigen. $0.105{\pm}0.041$ to BE antigen, $0.103{\pm}0.052$ to AE antigen, and $0.095{\pm}0.061$ to FE antigen. 6. Degree of correlation(r) in activity level of IgG between TE antigen and BE antigen was 0.905 ; between TE antigen and AE antigen, 0.760; between TE antigen and FE antigen, 0.790, and between AE antigen and FE antigen, 0.945. 7. As O.D. above 0.200 was determined positive for the serodiagnosis of pulmonary tuberculosis, the sensitivity and specificity in ELISA using TE antigen were 80% and 87% respectively, whereas in the case of using BE antigen, 66% and 100%; in the case of using AE antigen, 62% and 100%, and in the case of using FE antigen, 72% and 93%, respecitively.

• 한국미생물·생명공학회지
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• 제23권1호
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• pp.81-86
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• 1995

A Streptomyces strain YS-943, which produced amino acid antimetabolite, was isolated from soil. During the course of screening for new amino acid antimetabolites from the culture broth of Actinomycetes, we found that the strain produced a substance active against Gram-positive bacteria and its activity was reversed by L-methionine and L-histidine on the synthetic minimal agar medium in the culture broth.The morphological and cultural characteristics serve to identify the producing organism strain YS-943 as the genus Streptomyces. Fermentation was carried out in the synthetic medium at 28$\CIRC$C for 48 hours. The fermentation yield reached about 12 mg per liter of the broth. The YS-943 substance was obtained as white powder, mp 194$\CIRC$C and has the molecular formular of C$_{4}$H$_{8}$N$_{2}$O$_{4}$. Its structure was determined to be o-carbamyl-D-serine by spectroscopic data. It is active against some Gram-positive bacteria and reversed by L-methionine and L-histidine.

• 호남수학학술지
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• 제35권2호
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• pp.303-310
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• 2013

In this paper, we first show that $z_{{\kappa}X}:E_{cc}({\kappa}X){\rightarrow}{\kappa}X$ is $z^{\sharp}$-irreducible and that if $\mathcal{G}(E_{cc}({\beta}X))$ is a base for closed sets in ${\beta}X$, then $E_{cc}({\kappa}X)$ is $C^*$-embedded in $E_{cc}({\beta}X)$, where ${\kappa}X$ is the extension of X such that $vX{\subseteq}{\kappa}X{\subseteq}{\beta}X$ and ${\kappa}X$ is weakly Lindel$\ddot{o}$f. Using these, we will show that if $\mathcal{G}({\beta}X)$ is a base for closed sets in ${\beta}X$ and for any weakly Lindel$\ddot{o}$f space Y with $X{\subseteq}Y{\subseteq}{\kappa}X$, ${\kappa}X=Y$, then $kE_{cc}(X)=E_{cc}({\kappa}X)$ if and only if ${\beta}E_{cc}(X)=E_{cc}({\beta}X)$.

• East Asian mathematical journal
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• 제29권1호
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• pp.83-89
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• 2013

Observing that every Tychonoff space X has a weakly Lindel$\ddot{o}$f extension ${\kappa}X$ and the minimal basically diconneted cover ${\Lambda}{\kappa}X$ of ${\kappa}X$ is weakly Lindel$\ddot{o}$f, we first show that ${\Lambda}_{{\kappa}X}:{\Lambda}{\kappa}X{\rightarrow}{\kappa}X$ is a $z^{\sharp}$-irreducible map and that ${\Lambda}{\beta}X={\beta}{\Lambda}{\kappa}X$. And we show that ${\kappa}{\Lambda}X={\Lambda}{\kappa}X$ if and only if ${\Lambda}^{\kappa}_X:{\kappa}{\Lambda}X{\rightarrow}{\kappa}X$ is an onto map and ${\beta}{\Lambda}X={\Lambda}{\beta}X$.

• 접착 및 계면
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• 제18권1호
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• pp.13-24
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• 2017

본 연구에서는 50 wt%의 매우 높은 담지량과 70%의 높은 고형분을 가지면서도 물속이나 다양한 제품에 나노 입자 형태로 분산이 가능한 새로운 형태의 소수성 항균 물질 담지 나노 입자를 제조하였다. 실란 기능화 양친성 고분자 전구체(Alkoxysilane-functionalized Amphiphilic Polymer Precursor; 이하 AAPP)와 다양한 실란 화합물을 이용하여 전형적인 Hydrolytic Sol-Gel 공정으로 제조된 수분산 유-무기 하이브리드 나노 입자들을 제조하고, 이를 이용하여서 나노 침전법을 사용하여서 소수성 항균물질을 고함량으로 담지할 수 있는 새로운 공정으로 소수성 항균물질인 Eugenol이 담지된 유-무기 하이브리드 형태의 나노입자 제조하였다. 나노 입자 제조시 제조 조건의 변화에 따른 나노 입자들의 크기, 담지량, 항균 활성 및 방출거동 등에 영향을 미치는 인자들을 조사하였다. 나노 입자의 종류에 관계없이 Minimal Inhibitory Concentration (MIC)는 50 mg/ml로 동일하였고, 모든 균주에서 99 %에 해당하는 우수한 항균력과 Pseudomonas aeruginosa (PSE)를 제외하고는 2주 이상의 항균 지속력을 나타내었다. 특히, Tetraethoxysilane (TEOS)를 첨가한 경우에는 견고한 무기물 도메인으로 인해 가장 높은 담지량 (50 wt.%)과 서방출 (Sustained release)을 나타내었고, Hexanediol (HD)을 첨가한 경우에는 HD 자체의 항균력과 용매로서의 역할도 하였기 때문에 가장 높은 항균력과 70%의 고형분을 나타내었다.

• 미생물학회지
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• 제51권4호
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• pp.444-447
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• 2015

본 연구는 $SeO_2$의 메티실린-내성 S. aureus에 대한 항세균활성을 규명하고자 수행하였다. Disc diffusion method를 이용하여 $SeO_2$의 항세균 활성을 측정한 결과, 그람 양성 세균이 그람 음성 세균과 비교시 우수하였다. 사용한 그람 양성 세균 중 Streptococcus, Staphylococcs 속 세균이 Bacillus 속 간균과 비교시 더 우수하였다. 사용한 모든 MRSA에 항균활성이 나타났다. 항생제의 생육저지환을 측정한 결과, 사용한 모든 항생제에 대해 MRSA의 항균활성이 작게 나타났다. $200-500{\mu}g/disc$ 범위의 $SeO_2$ 적용시 S. aureus 및 S. aureus CCARM (MRSA)에 대한 생육저지환의 직경은 각각 20-32.7 mm 및 13.5-17.9 mm이었다. $SeO_2$의 MRSA에 대한 최소생육억제농도는 $40{\mu}g/ml$이었다. 액체배지에 0.5% 및 1%의 $SeO_2$를 첨가한 결과, MRSA의 생육이 억제 되었다. 본 $SeO_2$의 항균활성 실험 결과는 추후, $SeO_2$의 항균활성 기작의 규명, 병원성 세균 및 항생제-내성 미생물에 적용될 수 있다고 판단된다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권2호
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• pp.8-14
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• 2016

We compared the plausible reaction mechanism and quantitative efficiency of highly self-organized TiO₂ nanotube (ntTiO₂) film with TiO₂ powder. Film was fabricated by electrochemical potentiostatic anodization of titanium thin film in an ethylene-glycol electrolyte solution containing 0.3 wt% NH₄F and 2 vol% deionized water. Nanotubes with a pore size of 80-100 nm were formed by anodization at 60 V for 3 h. Humic acid (HA) was degraded through photocatalytic degradation using the ntTiO₂ film. Pseudo first-order rate constants for 0.3 g of ntTiO₂, 0.3 g TiO₂ powder, and 1 g TiO₂ powder were 0.081 min⁻¹, 0.003 min⁻¹, and 0.044 min⁻¹, respectively. HA adsorption on the ntTiO₂ film was minimal while adsorption on the TiO₂ powder was about 20% based on thermogravimetric analysis. Approximately five-fold more normalized OH radicals were generated by the ntTiO₂ film than the TiO₂ powder. These quantitative findings explain why ntTiO₂ film showed superior photocatalytic performance to TiO₂ powder.