• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기물성,응용부문
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• pp.147-149
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• 2002

Recently, the study on development of electrical and electronic device is done to set miniature, high degrees of integration and efficiency by using inorganic materials the study of Langmuir-Boldgett(LB) method that uses organic materials because of the limitation for the ultrasmall size. The structure of MIM(Metal-Insulator-Metal) device is Cr-Au/PBLG/ Al. the number of accumulated layers are 1, 3, 5, 7, 9. The I-V characteristic of the device is measured from 0[V] to 2[V] and the characteristic of current-time of the devices. We have investigated the capacitance because PBLG system have a accumulated layers the maximum value of measured current is increased as the number of accumulated layers are decreased. The capacitor properties of a thin film is better as the distance between electrodes is smaller. The results have shown the insulating materials and could control the conductivity by accumulated layers.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 센서 박막재료
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• pp.38-42
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• 2001

To observe the Langmuir films, displacement current measuring system(Nippon Laser & Electronics), $\pi-A$ isotherms measuring device, and Brewster Angle Microscope(BAM) were used. As results, for 8A5H, big tilt angle changes of many molecules were detected before liquid expanded phase when the monolayer was compressed and expanded by barrier. Also many small and bright points were detected by BAM when the displacement current radically changed. In $\pi$-A isotherms, surface pressure of 8A5H was radically decreased between 35 and 40[mN/m] and monolayer was assumed to be collapsed in solid condensed phase, since large bright domain was observed without change of displacement current and this bright boundary was not classified part of domain in BAM image. If we observe behaviors of molecules on the water surface in these three measurement at the same time, we can get more precise informations on L films and it could be good data for fabricating LB films.

• Macromolecular Research
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• 제16권4호
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• pp.373-378
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• 2008

A simple chemical fixation method for the fabrication of layer-by-layer (LbL) polyelectrolyte multilayer (PEM) has been developed to create a large area, highly uniform film for various applications. PEM of weak poly-electrolytes, i.e., polyallylamine hydrogen chloride (PAH) and poly(acrylic acid)(PAA), was assembled on polymer substrates such as poly(methyl methacrylate)(PMMA) and polycarbonate (PC). In the case of a weak polyelectrolyte, the fabricated thin film thickness of the polyelectrolyte multilayers was strongly dependent on the pH of the processing solution, which enabled the film thickness or optical properties to be controlled. On the other hand, the environmental stability for device application was poor. In this study, we utilized the chemical fixation method using glutaraldehyde (GA)-amine reaction in order to stabilize the polyelectrolyte multilayers. By simple treatment of GA on the PEM film, the inherent morphology was fixed and the adhesion and mechanical strength were improved. Both surface tension and FT-IR measurements supported the chemical cross-linking reaction. The surface property of the polyelectrolyte films was altered and converted from hydrophilic to hydrophobic by chemical modification. The possible application to antireflection coating on PMMA and PC was demonstrated.

• Journal of Microbiology and Biotechnology
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• 제17권1호
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• pp.29-36
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• 2007

The xynA gene encoding the xylanase A of Paenibacillus sp. DG-22 was isolated with a DNA probe obtained by PCR amplification, using degenerated primers deduced from the amino acid residues of the known N-terminal region of the purified enzyme and the conserved region in the family 11 xylanases. The positive clones were screened on the LB agar plates supplemented with xylan, by the Congo-red staining method. The xynA gene consists of a 630-bp open reading frame encoding a protein of 210 amino acids, and the XynA preprotein contains a 28-residues signal peptide whose cleavage yields a l82-residues mature protein of a calculated molecular weight of 20,000Da and pI value of 8.77. The cloned DNA fragment also has another ORF of 873 nucleotides that showed 76% identity to the putative transcriptional activator of Bacillus halodurans C-125. Most of the xylanase activity was found in the periplasmic space of E. coli. The xynA gene was subcloned into pQE60 expression vector to fuse with six histidine-tag. The recombinant xylanase A was purified by heating and immobilized metal affinity chromatography. The optimum pH and temperature of the purified enzyme were 6.0 and $60^{\circ}C$, respectively. This histidine-tagged xylanase A was less thermostable than the native enzyme.

• Korean Chemical Engineering Research
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• 제55권4호
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• pp.556-560
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• 2017

A hemoglobin/silver nanoparticle heterolayer was fabricated for bioelectronic device with electrochemical signal-enhancement effect. As a device element, a hemoglobin, the metalloprotein, contained the heme group that showed the redox property was introduced for charge storage element. For electron transfer facilitation, a silver nanoparticle was introduced for electrochemical signal facilitation, the hemoglobin was immobilized onto Au substrate using chemical linker 6-mercaptohexanoic acid (6-MHA). Then, the silver nanoparticle was immobilized onto fabricated hemoglobin/6-MHA heterolayers by layer-by-layer (LbL) method. The surface morphology and surface roughness of fabricated heterolayer were investigated by atomic force microscopy (AFM). The redox property of hemoglobin/silver nanoparticle heterolayer was investigated by a cyclic voltammetry (CV) experiment for obtaining an oxidation potential and reduction potential. Moreover, for the assessing charge storage function, a chronoamperometry (CA) experiment was conducted to hemoglobin/silver nanoparticle-modified heterolayer electrode using oxidation and reduction potentials, respectively. Based on the results, the fabricated hemoglobin/silver nanoparticle heterolayer showed that an increased charge storage effect compared to hemoglobin monolayer-modified electrode.

• KSBB Journal
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• 제25권2호
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• pp.123-129
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• 2010

An endospore-forming, rod-shaped bacterium was isolated from forest soil samples collected at the Taebaek mountain of Gangwon province, Korea, and taxonomically characterized by physiological, biochemical and phylogenetic methods. Its 16S rRNA sequences showed the maximum similarity of 97% with B. amyloliquefaciens. In addition, the isolate BCNU 2002 was determined to have the ability to produce enzymes such as amylase, protease, gelatinase and catalase. The in vitro antifungal activity of Bacillus sp. BCNU 2002 was also examined against human pathogenic fungi such as Aspergillus niger, Candida albicans, Epidermophyton floccosum, Saccharomyces cerevisiae, Trichophyton mentagrophytes and Trichophyton rubrum. A maximum production level of antifungal substances of Bacillus sp. BCNU 2002 was achieved under aerobic incubation at $28^{\circ}C$ for 7 days in LB broth. BCNU 2002 showed strong antifungal activities against T. mentagrophytes and T. rubrum with the range of percentage inhibition from 56.25 to 63.23%. It was also confirmed that ethylacetate extract of cultured broth showed a strong antifungal activity against A. niger, C. albicans, S. cerevisiae and T. rubrum by agar diffusion method. The peptide fraction also exhibited broad antifungal spectrum against various pathogenic fungi. The minimum inhibitory concentration values for active extracts ranged between 125 ${\mu}g$/mL and 1000 ${\mu}g$/mL.

• 생명과학회지
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• 제31권8호
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• pp.761-770
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• 2021

본 연구에서는 반응표면분석법을 이용하여 전통발효식품인 막걸리로부터 분리한 Bacillus amyloliquefaciens SRCM115785 균주에 대하여 protease 생산량을 증가시키기 위한 배지의 최적 농도를 확립하고자 하였다. 선정한 11개의 배지 성분 중 각 성분이 protease 생산에 미치는 영향에 대한 분석을 위해 Plackett-Burman design (PBD)를 설계하여 통계분석한 결과 glucose, yeast extract, beef extract를 protease 생산 향상을 위한 요인으로 최종 선별하였다. 선별된 3개의 성분에 대해 protease 생산을 위한 각 성분별 최적 농도를 결정하기 위해 central composite design (CCD)분석을 설계하여 protease 최대 생산을 위한 각 배지조성별 농도는 glucose 6.75 g/l, yeast extract 12.42 g/l, beef extract 17.48 g/l로 예측되었다. ANOVA 분석을 통해 실험모델의 적합성을 증명하였고, 설계한 최적배지에서 반복실험을 진행하여 protease 생산량을 측정한 결과 예측값과 매우 유사한 값을 나타냄을 확인하였다. 최종적으로 일반 배지에 비해 137% 환이 증가하였으며, 추가로 정량 분석 결과 기존 25.72 U/ml 대비 59.28 U/ml로 230.47% 증가함을 확인하였다. 본 연구를 통해 protease 생산량 증가를 위한 배지 성분의 최적화를 확립하였고, 이를 바탕으로 산업용 효소로서 protease의 효율적인 활용방안에 대한 기초자료로서 활용될 수 있을 것으로 기대된다.

• 한국응용곤충학회지
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• 제57권4호
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• pp.393-399
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• 2018

고리매개등온증폭법(LAMP)으로 흰등멸구를 특이적으로 구별해낼 수 있는 프라이머 세트(WBPH-65)가 핵내 ITS2영역의 전체염기서열(KC417469.1)을 바탕으로 설계 제작되었다. WBPH-65는 총 6개의 프라이머, F3 (18 bp), B3 (18 bp), FIP (43 bp), BIP (40 bp), LF (21 bp), LB (25 bp)로 구성되는데, 전체 합한 길이가 165 bp이다. WBPH-65를 흰등멸구, 벼멸구 및 애멸구의 게놈 DNA와 $65^{\circ}C$에서 60분간 고리매개등온증폭 반응시켰을 때, 흰등멸구 시료에서만 증폭 산물들이 관찰되었다. $65^{\circ}C$에서 WBPH-65와 흰등멸구 게놈 DNA의 양과 반응시간을 달리하여 형광반응을 관찰하였을 때 40분 반응에서는 10과 100 ng DNA에서, 60분 반응에서는 0.01, 0.1, 1, 10, 100 ng DNA에서 발광여부가 명확히 구별되었다. 그러나 20분과 30분 반응에서는 준비된 모든 DNA 양에서 발광여부 구별이 어려웠다. 한편, WBPH-65에서 LF와 BF 프라이머를 뺀 경우 60분 반응에서는 벼멸구, 애멸구 뿐만 아니라 흰등멸구의 게놈 DNA에서도 발광되지 않았다. 본 연구 결과로부터 WBPH-65가 60분 이내 반응에서 흰등멸구를 특이적으로 구별하기 위해서는 6개의 프라이머가 모두 필요하며 최소한 벼멸구와 애멸구를 구별해낼 수 있음을 확인하였다.

• Elastomers and Composites
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• 제43권4호
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• pp.264-270
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• 2008

3-아미노프로필메톡시 실란을 처리한 반응성 있는 유리표면 위에 "LbL" 방법을 사용하여 $\alpha$-D-만노실 풀러렌[$C_{60}$]-금 나노입자를 자기조립 하였다. 표면 처리한 유리막을 $\alpha$-D-만노실 풀러렌[$C_{60}$]과 헥산 티올레이트/아미노 티오페녹사이드-금나노입자를 포함하고 있는 용액속에 교대로 담그었다. $\alpha$-D-만노실 풀러렌[$C_{60}$] -금 나노입자 필름을 시간에 따라 다중성(5층)막으로 제조하였다. 자외선-가시광선 분광기를 사용한 자기조립 나노입자 필름의 분석은 530 nm 일 때 금 나노입자의 표면 플라스몬 밴드로 인해 다중성(5층)막이 형성되는 것을 보여주었다.

• Journal of Applied Biological Chemistry
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• 제52권1호
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• pp.1-7
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• 2009

후대교배종 CM 벼의 정성 PCR 검정방법을 개발하기 위하여, 벼의 내재유전자로써 OsCs-J(rice cytochrome c gene)을 선발하여 OsCytC-5'/3'의 primer쌍을 제작하고, 벼를 포함한 서로 다른 8개 작물에 대하여 PCR을 수행한 결과 벼에 특이적으로 증폭되는 111 bp의 반응 산물을 확인하였다. 국내 개발된 LS28$\times$CryIAc1 GM 벼의 검정 분석으로 정성 PCR 반응을 수행하였다. 정성 PCR을 위하여 GM 벼에 도입된 T-DNA 및 게놈상의 도입유전자 삽입부위의 인접서열을 바탕으로 구조 및 계통 특이적인 검정 primer 쌍을 제작하였다. ActCk-5'/3' primer 쌍을 이용하여 LS28의 T-DNA 내의 actin 프로모터와 OsCK1 유전자 사이를 증폭시켜 306 bp의 PCR 반응 산물을 얻을 수 있었으며, 또한 계통특이 primer 쌍인 CryIAc1 GM 벼유래의 CrLB-5'/3' 및 LS28 GM 벼 유래의 CKRB-5'/3'를 이용한 PCR 반응으로 각각 142 bp와 91 bp의 도입유전자의 인접서열 부위의 특이적인 증폭 산물을 확인할 수 있었다. 계통 특이적 검정을 위한 이들 개발 primer 쌍들은 event 계통과 대조적으로 non-GM 벼와 다양한 작물에 대하여 어떠한 특이적인 PCR 증폭 산물을 형성하지 않았다. 따라서 본 연구에서 계통특이 primer를 이용하여 후대교배종 GM 벼 계통, L528$\times$CryIAc1을 특이적으로 검출할 수 있음을 확인하였고, 제시된 방법이 GM 벼의 실용화를 위한 위해성평가의 검정방법 자료로 제공될 수 있음을 확인하였다.