• Title/Summary/Keyword: Covalently

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Correlation between signal pathway of chitosan and nitric oxide

  • Yoon, Hyun-Joong;Kim, Young-Ho;Park, Haeng-Soon
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.222.2-223
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    • 2003
  • Renal dipeptidase (RDPase, EC 3.4.13.19), an ectoenzyme of renal proximal tubules, is covalently bound to outer leaflet of lipid bilayer via glycosylphosphatidylinositol (GPI)-anchor. Chitin is a major component of the shells of crustacea such as crab, shrimp and crawfish. This study was conducted to examine the effect of chitosan on RDPase release from renal proximal tubules. Nitric oxide (NO), highly reactive free radical, inhibits the release of RDPase from porcine proximal tubules. (omitted)

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A New Approach to Synthesis and Photoluminescence of Silicon Nanoparticles

  • Kim, Beomsuk
    • Journal of Integrative Natural Science
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    • v.2 no.1
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    • pp.28-31
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    • 2009
  • We describe the synthesis and characterization of silicon nanoparticles prepared by the soluton reduction of SiCl4. These reactions produce Si nanoparticles with surfaces that are covalently terminated. The resultant organic derivatized Si nanoparticles as well as a probable distribution of Water-soluble Si nanoparticles are observed and characterized by photoluminescence(PL) spectroscopy. This work focuses originally on the organic- and water-soluble silicon nanoparticles in terms of the photoluminescence. Further this work displays probably the first layout of hydrogen terminated Si nanoparticles synthesized in solution at room temperature.

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Covalent Binding of DNA onto Glass Support for the Construction of Genosensor

  • Jeong, U-Seong;Baek, Se-Hwan
    • 한국생물공학회:학술대회논문집
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    • 2000.11a
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    • pp.709-710
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    • 2000
  • Genosensor technology utilizes a patterned array of DNA molecules immobilized on solid supports for biomedical analysis. The detection capability of the sensor depended mainly on the way the capture probes are attached to the support as well as the sequence. We compared two different. coupling methods currently used to covalently graft DNA molecules onto a glass surface.

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Salmonella species 검출용 DNA Probe 분석시스템 고안

  • Lee, Ung-Hui;Baek, Se-Hwan
    • 한국생물공학회:학술대회논문집
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    • 2000.11a
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    • pp.711-712
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    • 2000
  • DNA probe assay comprising a microwell as' solid matrix for the immobilization of streptavidin (SA) and an oligonucleotide with covalently bound fluorecein as detection probe was developed. The insolubilized SA captured the biotinylated DNA product of polymerase chain reaction (PCR), and the product was denatured under a basic condition. The remaining single-stranded DNA on the solid surface was hybridized with the probe for signal generation that was performed based on enzyme-linked immuno -reactions.

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Natural Halogenated Organic Compounds (천연(天然) Halogen 유기화합물(有機化合物)에 대(對)하여)

  • Han, Koo-Dong
    • Korean Journal of Pharmacognosy
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    • v.7 no.3
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    • pp.159-169
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    • 1976
  • The present review records the known structures of more than 80 organic compounds containing halogens, which may be considered naturally occurring. The format of the review is based on the viewpoint of biochemists. Compounds containing one type of halogen atom have been placed in one of four major division, i.e., structures possessing fluorine, chlorine, bromine or iodine covalently bonded to carbon. Within each major division molecular structures are given along with the species from which the compounds have been isolated, The biological significance, if any, is also mentioned.

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White-Light-Emitting Molecule

  • Park, Soo-Young;Park, Sang-Hyuk
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.481-481
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    • 2009
  • For a new generation of white light sources, we present the first example of a concentration-independent ultimate white-light-emitting molecule based on excited-state intramolecular proton transfer materials. Our molecule is composed of covalently linked blue- and orange-light-emitting moieties between which energy transfer is entirely frustrated, leading to the production of reproducible, stable white photo- and electroluminescence.

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Analysis of Lambda Site-specific Recombination Inermediates Generated by Synthetic Substrates (합성 기질에 의해 형성된 Lambda Site-specific Recombination 중간 대사물의 분석)

  • 이나영;유승구
    • Microbiology and Biotechnology Letters
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    • v.23 no.3
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    • pp.282-287
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    • 1995
  • Integrase (Int) carries out the cutting and resealing of attachment (att) site DNA via a covalent Int-DNA intermediate. A family of synthetic substrate DNAs was designed to accumulate Int-DNA intermediate. Int-DNA intermediates accumulated by half substrate was analyzed by SDS- KCI precipitation and restriction digestion. The results showed that Int-half DNA intermediate was circular and contained covalently bound Int molecule. Int-DNA intermediates were also trapped with three other kinds of synthetic substrates.

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Flexible docking of novel antitumor agents into human topoisomerase I-DNA complex with FlexiDock

  • Woo , Su-Na;Kim, Choon-Mi
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.314.2-314.2
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    • 2002
  • DNA topoisomerases catalyze changes in DNA topology through cycles of transient DNA strand breakage and religation. During this process. the active site tyrosine in human DNA topoisomerase Ⅰ(Top Ⅰ) becomes covalently linked to the 3'-ends of a single-stranded nick in the DNA duplex, Stabilization of the Top Ⅰ-DNA cleavable complex is the common initial event leading to the cytotoxicity of top 1 inhibitors. (omitted)

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Effects of chitosan on the decreased renal dipeptidase release by nitric oxide from renal proximal tubules

  • Yoon, Hyun-Joong;Park, Eun-Mi;Park, Haeng-Soon
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.319.2-319.2
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    • 2002
  • Chitin is a major component of the shells of crustacea such as crab. shrimp and crawfish. Renal dipeptidase (RDPase. EC 3.4.13.19), an ectoenzyme of renal proximal tubules. is covalently bound to outer leaflet of lipid bilayer via glycosylphosphatidylinositol (GPI)-anchor. The biological role of RDPase was suggested as the hydrolysis of dipeptide into free-amino acids before renal reabsorption. The underlying biochemical mechanism of decreased RDPase release was suggested as nitric oxide (NO) production. (omitted)

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The Electrochemical Characteristics of MEA with Pt/Cross-Linked SPEEK-HPA Composite Membranes/Pt-Ru for Water Electrolysis (수전해용 Pt/공유가교 SPEEK-HPA 복합막/Pt-Ru MEA의 전기화학적 특성)

  • Hwang, Yong-Koo;Woo, Je-Young;Lee, Kwang-Mun;Chung, Jang-Hoon;Moon, Sang-Bong;Kang, An-Soo
    • Transactions of the Korean hydrogen and new energy society
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    • v.20 no.3
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    • pp.194-201
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    • 2009
  • The e1ectrocatalytic properties of heteropolyacids(HPAs) entrapped in covalently cross-linked sulfonated polyetheretherketone(CL-SPEEK/HPA) membranes have been studied for water electrolysis. The HPAs, including tungstophosphoric acid(TPA), molybdophosphoric acid(MoPA), and tungstosilicic acid(TSiA) were used as additives in the composite membranes. The MEA was prepared by a non-equilibrium impregnation-reduction(I-R) method, using reducing agent, sodium borohydride(NaBH4) and tetraamineplatinum(II) chloride(pt(NH$_3$)$_4$Cl$_2$). The electrocatalytic properties of composite membranes such as the cell voltage were in the order of magnitude CL-SPEEKlMoPA40 (wt%) > /TPA30 > /TSiA40. In the optimum cell applications for water electrolysis, the cell voltage of PtlPEM/Pt-Ru MEA with CL-SPEEKlTPA30 membrane was 1.75 V at 80$^{\circ}$C and I A/cm$^2$ and this voltage carried lower than that of 1.81 V of Nafion 117. Consequently, in regards of electrochemical and mechanical characteristics and oxidation durability, the newly developed CL-SPEEKITPA30 composite membrane exhibited a better performance than the others, but CLSPEEKlMoPA40 showed the best electrocatalytic activity (1.71 Vat 80$^{\circ}$C and 1 A/cm$^2$) among the composite membranes.