• Title/Summary/Keyword: membrane chemistry

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Antimicrobial effect of chitosan oligosaccharides, prepared under ultrafiltration membrane bioreactor, against pathogenic bacteria causing flounder fish diseases in aquacultural farm

  • Heo, Moon-Soo;Jeon, You-Jin;Lee, Ki-Wan;Song, Choon-Bok;Lee, Jehee;Yeo, In-Kyo;Yang, Byung-Gyoo;Kim, Se-Kwon
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2001.10a
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    • pp.145-146
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    • 2001
  • Despite a variety of development in fish farming during the last decades, fish diseases by bacteria, virus, and parasites are still major problems in aquaculture. Aquaculture of Hounder fish is widely performed around Korea as well as Jeju island, due to relatively stable seed production, short farming period, and a higher value in market. However, intensive feeding and environmental pollution in aquacutural farm act as a great limiting factor in economic aspect. (omitted)

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Antimicrobial effect of chitosan oligosaccharides, prepared under ultrafiltration membrane bio-reactor, against hygienic bacteria of Vibrio spp.

  • Jeon, You-Jin;Heo, Moon-Soo;Lee, Ki-Wan;Ha, Jin-Hwan;Kim, Soo-Hyun;Yang, Byung-Gyoo;Kim, Se-Kwon
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2001.10a
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    • pp.147-148
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    • 2001
  • Many people living in Asia countries, particularly Korea, Japan and China, have consumed very widely fresh seafood products, such as shrimps, oysters, mussels and other marine invertebrates and fishes, without any heating or cooking. A variety of Vibrio spp., including V. parahaemolyticus, V. cholera. V. vulnificus, and V. fluvialis, lives in these seafoods and cause great problems associated with human disease. A strong antimicrobial agent to effectively inhibit the growth of these pathogenic bacteria in in vivo or in vitro is urgently need for preventing fish and human diseases. (omitted)

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Antimicrobial effect of chitosan oligosaccharides, prepared under ultrafiltration membrane bioreactor, against Vibrio spp. causing fish diseases

  • Lee, Jehee;Jeon, You-Jin;Heo, Moon-Soo;Lee, Ki-Wan;Song, Choon-Bok;Yeo, In-Kyo;Yang, Byung-Gyoo;Kim, Se-Kwon
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2001.10a
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    • pp.151-152
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    • 2001
  • Chitin, a polymer of N-acetylglucosamine ($\beta$-1,4 linked 2-acetamido-D-glucose), is a cellulose-like biopolymer present richly in the exoskeleton of crustaceans and in cell walls of fungi, insects and yeast. Chitosan is derived from chitin by deacetylation, to different degrees, in the presence of alkali. [l]. Recent studies for chitin and chitosan have been concentrated in bioactivities such as antitumor activity, immuno-enhancing effects, enhancing protective effects against infection with some pathogens in mice, and antimicrobial activeity [2]. (omitted)

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Ovum-Membrane Denudation Activities of the Purified Acrosomal Glycosidases and Sulfatase (정제된 아크로솜의 글라이코시데이스들과 썰파테이스들의 난자막 침투의 활성도)

  • Yang, Chul-Hak
    • Clinical and Experimental Reproductive Medicine
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    • v.8 no.1
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    • pp.19-22
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    • 1981
  • 정자 아크로좀이나 정액중에서 고순도로 정제된 탄수화물 분해효소들 및 썰파테이스를 개별적으로 또는 여러 조합으로 사용하여 난자막의 용해를 조사하였다. 베타 굴룩유로니데이스와 베타-엔-에시틸글루코사미니데이스가 전혀 없이 정제된 황소 정자의 하이얄유로니데이스는 토끼의 난자막중 큐믈러스층을 쉽게 분해시켰다. 토끼의 정자에서 얻은 아릴썰파테이스와 위의 하이얄유로니데이스는 더욱 빨리 토끼난자의 큐믈러스층을 용해시켰다. 한편 아릴썰파테이스는 하이얄유로니데이스나 베타-엔-에시틸 글루코사미니데이스들도 하이얄 유로니데이스들과 아릴썰파테이스들처럼 큐믈러스츨을 용해시켰으나 모든 경우에 난자의 코로나층이나 조나펠루시다층에는 아무런 변화를 주지 않고 있다.

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Electropolymerized Thin Bilayers of Poly-5-amino-1-naphthol and Poly-1,3-phenylendiamine for Continuous Monitoring Glucose Sensors

  • Chung, Taek-Dong
    • Bulletin of the Korean Chemical Society
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    • v.24 no.3
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    • pp.291-294
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    • 2003
  • A highly interferent-resistive membrane, poly-5-amino-1-naphthol (poly-5A1N), underlied beneath enzymeembedded poly-1,3-phenylendiamine (poly-m-PD) network for miniturized continuous monitoring glucose sensors. The enzyme layer was prepared from a mixed solution of glucose oxidase (GOx) and m-PD monomer by simple electrolysis. The mass change of poly-5A1N was monitored by electrochemical quartz crystal microbalance (EQCM) in situ and the corresponding thickness was measured. Successive electropolymerization of poly-5A1N and poly-m-PD create a several tens nm-thick bilayer showing excellent selectivity for $H_2O_2$ and low activity loss of immobilized enzymes.

Fabrication and Evaluation of a New High-Temperature pH Sensor for Use in PWR Nuclear Power Plants

  • Jung, Yong-Ju;Yeon, Jei-Won
    • Bulletin of the Korean Chemical Society
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    • v.31 no.10
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    • pp.2939-2942
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    • 2010
  • A new high-temperature pH sensor has been successfully developed by reforming the internal reference systems of the pH sensors based on oxygen-ion conducting ceramic membrane. The conventional internal reference system, a mixture of Ni and NiO, has been replaced with partially oxidized Ni powders, where Ni and NiO coexist on the surface of particles, in order to avoid the cumbersome mixing step of Ni and NiO particles. The partially oxidized Ni particles were made by oxidizing Ni under air atmosphere at $600^{\circ}C$ and characterized by X-ray diffraction (XRD) and FTIR spectroscopy. The viability of the pH sensor developed was assessed in boric acid (1000 ppm-B)/ lithium hydroxide (1 to 3 ppm-Li) buffer solutions at $280^{\circ}C$. The pH sensor showed excellent accuracy with a small error less than ${\pm}0.2$ pH units.

A Study on the Characteristics of Topological Invariant Expression in the Space of Digital Architecture (디지털건축공간에 나타난 위상기하학적 불변항의 표현특성에 관한 연구)

  • Bae Kang-Won;Park Chan-Il
    • Korean Institute of Interior Design Journal
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    • v.14 no.3 s.50
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    • pp.64-72
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    • 2005
  • The purpose of this study is to propose a topological design principles and to analyze the space of digital architecture applying topological invariant expressive characteristics. As this study is based on topology as a science of true world's pattern, we intented to explain the concepts and provide some methods of low-level and hyperspace topological invariant Properties. Four major aspects are discussed. Those are connection theory, boundary concept, homotopy group, knot Pattern theory as topological invariant properties. Then we intented to make understand topological characteristics of the Algorithms, luring machine, cellular automata, string theory, membrane, DNA and supramolecular chemistry. In fine, the topological invariant properties of the digital architecture as genetic algorithms based on self-organization and heterogeneous networks of interacting actors can be analyzed and used as a critical tool. Therefore topology can be provided endless possibilities for architecture, designers and scientists intended in expressing the more complex and organic patterns of nature as life.

Synthesis of Lipophilic Benz[cd]indole Antifolates and Their Antitumor Activity In Vitro (지용성 Benz[cd]indole 엽산길항제의 합성 및 In Vitro 항암활성)

  • Baek Du-Jong
    • YAKHAK HOEJI
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    • v.49 no.1
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    • pp.60-67
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    • 2005
  • Nonclassical aminobenz[cd]indole antifolates 4, 5 and 6, in which the glutamic acid moiety of the classical antifolates is substituted by 2-phenylglycinamide or 3-aminobenzamide, were synthesized and their in vitro antitumor activity was evaluated. The purpose of this substitution is that the lipophilicity is enhanced due to the aromatic ring of the target compounds for the passive transport through lipid membrane of cells while the hydrogen bonding of the amide is retained in the active site of the enzyme, thymidylate synthase, where the glutamate is originally present. The target compounds were highly cytotoxic against tumor cell lines of murine and human origin with micromolar to nanomolar $IC_{50}$ values. Most effective was compound 4 ($N^6-methyl-N^6$-[4-[(${\alpha}$(S)-aminocarbonylbenzyl) aminocarbonyl]benzyl]-2,6-diaminobenz[cd]indole)with $IC_{50}$ of 2 nM against SW480, human colon adenocarcinoma cell line, which is 650-fold more potent than the reference compound 3.

Natural TACE (TNF-$\alpha$ Convertase) Inhibitor, Gelastatin Hydroxamate: Biological Evaluation and Target Validation

  • Chun, Tae-Gyu;Lee, Jin-Ha;An, Mi-Hyun;Park, Song-Kyu;Lee, Hee-Yeon;Han, Gyoon-Hee
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.173.1-173.1
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    • 2003
  • One of attractive target for Rheumatoid Arthritis (RA) therapy is the cytokine, tumor necrosis factor-alpha (TNF-$\alpha$), which has been shown to be overproduced in the joint of RA patients. The clinical success of anti- TNFR biologics has validated TNF-$\alpha$ as a drug discovery target. Thus, inhibiting of formation of TNF-$\alpha$ has been emerged to an intriguing approach for RA therapy. TNF-$\alpha$ is processed from its membrane bound precursor by the metalloprotease TNF-$\alpha$ converting enzyme (TACE), Here, biological evaluation, mode of action of natural TACE inhibitor, Gelastatin hydroxamate, are addressed. (omitted)

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Postchilling Accumulation of Superoxide in Cells and Chilling Injury in Rice Plant (Superoxide의 세포내 축적과 벼냉해의 발현)

  • Kim, Jong-Pyung;Hyun, Il;Jung, Jin
    • Applied Biological Chemistry
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    • v.30 no.4
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    • pp.364-370
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    • 1987
  • The $O_2^-$ level of the extract from young rice leaves, which was cold treated for 2 days and then placed at room temperature for a period of time significantly higher than that from tissues untreated. $O_2^-$ level in leaves was practically unchanged during cold treatment for 48 hours. But it started to increase to arrive at maximum in 8 hours, once the plants were placed under room temperature. The abnormal production of $O_2^-$ in mitochondria during postchilling process was interpreted as a biochemical consequence of accumulation of glycolysis product(s) in cytosol and/or NADH in mitochondrial matrix due to disruption of catabolic balance at low temperature. Mitochondria isolated from the chilling injured tissue was found to have lost considerably their respiratory activity. This fact may imply the involvement of intramitochondrial accumulation of $O_2^-$ in the inactivation of electron transport chain system. The observation that mitochondria in the presence of the $O_2^--producing$ enzymatic system (Xanthine/Xanthine oxidase) lost their respiratory activity supports this inference. It was also found in this work that Superoxide dismutase (SOD) is a substrate inducible enzyme, and that SOD is a possible protective agent in plant cell against chilling injury.

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