• Applied Biological Chemistry
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• 제38권5호
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• pp.371-375
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• 1995

식물 병원성 사상균 F. oxysporum과 R. solani에 대하여 우수한 길항력을 갖는 Pseudomonas (P.) fluorescens를 작물 근권으로 부터 분리하여 생리, 생화학적 특성을 조사하였다. 이들 분리 근권길항 미생물중 한 균주인 Ps70과 plasmid pSV2-neo를 이용하여 electroporation에 의한 길항 미생물 P. fluorescens의 transformation 가능성과 최적 조건을 조사하였다. 그 결과 10% glycerol을 P. fluorescens buffer로 사용하여 2.5kV의 voltage, $200{\Omega}$의 resistance에서 최적의 electrotransformation 효과를 보였다. 또한, 이균주에 크기가 서로 다른 plasmid를 electroporation하여 transformation 효과를 비교한 결과 voltage, electroporation buffer의 조성, 그리고 resistance (time constant)가 transformation의 효과를 증진하는데 주요한 역할을 하는것으로 나타났으며, 또 다른 P. fluorescens 균주에 같은 실험을 반복한 결과 유사한 electrotransformation 효과를 보였다.

• 폴리머
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• 제35권6호
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• pp.586-592
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• 2011

본 연구에서는 전바나듐 레독스-흐름 전지용 음이온교환막의 제조를 위하여 vinylbenzyl chloride-co-styreneco-hydroxyethyl acrylate(VBC-co-St-co-HEA) 공중합체를 합성하였으며, 아민화 및 가교 반응을 통하여 음이온교환막을 제조하였다. 구조확인을 위하여 FTIR, $^1H$ NMR, TGA, GPC 분석을 하였으며, 음이온교환막의 함수율, 이온교환용량, 전기저항, 이온전도도 및 전바나듐 레독스-흐름 전지의 효율을 측정하였다. 음이온교환막의 이온교환용량, 전기저항, 이온전도도는 각각 1.17 meq/g, $1.9{\Omega}{\cdot}cm^2$, 0.009 S/cm이었으며, 전바나듐 레독스-흐름 전지 효율 실험 결과 충 방전효율, 전압효율 및 에너지효율은 각각 99.5, 72.6, 72.1%이었다.

• 한국지반공학회논문집
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• 제19권5호
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• pp.263-272
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• 2003

여러 가지 형식의 지오신세틱스가 개발되고 있는데, 설계 수명에 대한 신뢰성, 화학적 생물학적 내구성, 그리고 천공(꿰뚫림)에 대한 저항성 등에 대한 문제가 있는데도 불구하고 이들의 적용 분야는 증가 추세에 있다. 토공구조물이나 차수구조물에서 천공(꿰뚫림) 저항에 대한 문제는 해결되어야 할 중요한 문제로 드러나고 있다. 본 연구에서는 차수구조에 사용되는 여러 가지의 지오신세틱스의 천공(꿰뚫림) 저항성에 대하여 모형실험을 통하여 비교 분석하였다. 지오신세틱스에 천공(꿰뚫림)을 발생시키는 기구로서 두 가지 형식의 기구와 강자갈 그리고 쇄석을 사용하였다. 연구결과에 따르면, 천공기구의 형태는 재료의 천공(꿰뚫림)저항성에 큰 영향을 끼치고, 천공(꿰뚫림)강도의 크기는 천공(필뚫림) 발생기구의 형태와 재료에 따라 불규칙적인 것으로 나타났다.

• Bulletin of the Korean Chemical Society
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• 제34권11호
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• pp.3345-3349
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• 2013

Hsp90 shows great promise as a therapeutic target due to its potential to disable multiple signaling pathways simultaneously. In this study, we discovered that a natural product, butein moderately inhibited the growth of drug-resistant cancer cells (A2780cis and H1975), and brought about the degradation of oncogenic Hsp90 client proteins. The study demonstrated that butein would be a therapeutic lead to circumvent drug-resistance in cancer chemotherapy. The structure-based screening, synthesis, and biological evaluation of butein are described herein.

• 대한의용생체공학회:의공학회지
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• 제14권4호
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• pp.333-340
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• 1993

The high biocompatibility of titanium is connected with the high corrosion resistance of the surface oxide, its high dielectric constant, and some other specific biochemical properties of the oxide. The corrosion resistance of titanium can be improved with the formation of passive film by anodic oxidation. In other to characterize the titantium oxlde film formed by anodic oxidation, titanium plates were anodized in 0.5M $H_3SO_4$ electrolyte at voltages between 5V and 100v. The oxide film was examined by an X-Ray Diffractometer(XRD) and a Scanning Electron Microscope(SEM). In addition, the corrosion resistance of oxide film was tested by dipping in physiological NaCl,5% HCI,5% $H_3PO_4$ and its biocompatability was evaluated by the fibroblast-like cell culture. The results obtained are as follows : 1. The thickness of surface oxide and micropore are increased with the increase of electrode potential and formed deeply along the grain boundary. 2. The solubilities of titanium in electrolyte solution shows that the anodized titanium has more corrosion resistance than the untreated pure titanium. 3. The biocomatibility of anodized titanium is superior to untreated pure titanium.

• 농약과학회지
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• 제10권1호
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• pp.50-55
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• 2006

본 연구는 강원도 고랭지 배추경작지에서 채집한 chlorpyrifos 포장저항성 계통의 배추좀나방에서 추출한 무독화 효소 esterases와 glutathione-S-tranferase(GST)의 활성과 단백질의 sequestration 비율 및 acetylcholinesterase(AChE) insensitivity를 측정하여 저항성 발달기작을 구명하고자 수행되었다. Esterases의 경우 저항성과 감수성 배추좀나방간의 활성 차이는 없었으나, 전기영동상에서는 특정 isozyme의 차이가 확인되었으며, GST 활성은 포장저항성 계통이 감수성 계통보다 약 1.5배 높았다. 두 계통 간 단백질의 sequestration 차이는 없었으며, chlorpyrifos에 대한 AChE의 sensitivity는 포장저항성 계통의 AChE가 감수성계통보다 약 460배 낮은 것으로 확인되었다. 이러한 결과는 실내에서 저항성을 유도하여 파악한 배추좀나방의 저항성 특성결과와 동일한 것으로 강원도 고랭지 chlorpyrifos 포장저항성 배추좀나방의 저항성 발달은 AChE의 insensitivity가 주요 요인이며, 부가적으로 GST의 활성 변화도 작용하는 것으로 판단되었다.

• Molecules and Cells
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• 제26권2호
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• pp.107-112
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• 2008

Invasion mechanisms of pathogens and counteracting defense mechanisms of plants are highly diverse and perpetually evolving. While most classical studies of plant defense have focused only on defense-specific factor-mediated responses, recent work is beginning to shed light on the involvement of non-stress signal components, especially growth and developmental processes. This shift in focus links plant resistance more closely with growth and development. In this review, we summarize our current understanding of how pathogens manipulate host developmental processes and, conversely, of how plants deploy their developmental processes for self-protection. We conclude by introducing our recent work on UNI, a novel R protein in Arabidopsis which mediates cross-talk between developmental processes and defense responses.

• Bulletin of the Korean Chemical Society
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• 제6권4호
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• pp.210-214
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• 1985

Urokinase, a plasminogen activator, was conjugated with dextran by the cyanogen bromide activation-coupling method. The resulting water-soluble conjugate was purified by gel permeation chromatography on Sephadex G-200. The maximal activity was obtained when the ratio of urokinase/dextran was 1/20 for the coupling. The final preparation showed 5 CTA units/mg conjugate, 300 CTA units/mg protein, 8.4 % activity retention, and 47 % protein retention. The urokinase-dextran conjugate had good thermal, pH and storage stabilities. In addition, it showed greater resistance to the inhibitory effect of human plasma than native urokinase. Also in vitro biological half-life of urokinase increased 40 times by this conjugation. In view of activity, excellent stability and increased half-life, the conjugate can be a potential fibrinolytic agent in an injectable form.

• The Plant Pathology Journal
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• 제38권2호
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• pp.167-174
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• 2022

Pseudomonas amygdali is a hemibiotrophic phytopathogen that causes disease in woody and herbaceous plants. Complete genomes of four P. amygdali pathovars were comparatively analyzed to decipher the impact of genomic diversity on host colonization. The pan-genome indicated that 3,928 core genes are conserved among pathovars, while 504-1,009 are unique to specific pathovars. The unique genome contained many mobile elements and exhibited a functional distribution different from the core genome. Genes involved in O-antigen biosynthesis and antimicrobial peptide resistance were significantly enriched for adaptation to hostile environments. While the type III secretion system was distributed in the core genome, unique genomes revealed a different organization of secretion systems as follows: type I in pv. tabaci, type II in pv. japonicus, type IV in pv. morsprunorum, and type VI in pv. lachrymans. These findings provide genetic insight into the dynamic interactions of the bacteria with plant hosts.

• Mycobiology
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• 제51권5호
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• pp.333-342
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• 2023

Phytophthora species, classified under Oomycota, cause significant damage to various crops and trees. The present study introduced Phytophthora species, P. nagaii and P. tentaculata, new to Korea, which pose notable risks to their respective host plants. Our research provided a comprehensive description of these species taking into account their cultural features, morphological characteristics, and molecular phylogenetic analysis using the internal transcribed spacer rDNA region and cytochrome c oxidase subunit mtDNA genes (cox1 and cox2) sequences. In addition, this study first evaluated the sensitivity of P. nagaii and P. tentaculata to five anti-oomycete fungicides, finding both species most responsive to picarbutrazox and P. tentaculata resistant to fluazinam. The data can guide targeted treatment strategies and offer insights into effective control methods. The findings expand our understanding of the diversity, distribution, and management of Phytophthora species in Korea.