• 제목/요약/키워드: covalent

검색결과 368건 처리시간 0.019초

Preparation of Novel Iron Phthalocyanine Containing Reactive Groups and its Deodorizing Property on Cellulose

  • Kim, Eun-Mi;Choi, Jae-Hong
    • 한국염색가공학회지
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    • 제25권4호
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    • pp.247-253
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    • 2013
  • The enzyme-like catalytic functions of metal complex phthalocyanine derivatives those containing carboxylic acid groups could be applied as odor-removing systems and antibacterial systems. Pyromellitic dianhydride and 4-nitrophthalimide were used as starting material for synthesizing dinitro-tetracarboxylic acid iron phthalocyanine(compound 1). Then diamino-tetracarboxylic phthalocyanine(compound 2) was obtained by reduction of compound 1. For the formation of covalent bond with cellulose fiber, cyanuric chloride was introduced to the amino group of compound 2 by condensation reaction compound 3. The exhaustion method was employed for adsorbing compound 3 on cotton fiber. K/S values of each fabrics were measured by a CCM system and deodorizing rates were tested by a detector tube method for ammonia gas. K/S values of treated cotton fiber with compound 3 were arranged from 2.1 to 4.2 at $90^{\circ}C$ of exhaustion temperature. Deodorizing rates provided result of 81%, 84%, 88%, 91%, by passing time of 30 min, 60 min, 90 min, 120 min, respectively.

혈액중 포도당과 젖산의 분석을 위한 광섬유 생물센서 (Fiber-optic biosensor for analysis of glucose and lactate in blood samples)

  • 손옥재;이종일
    • 센서학회지
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    • 제15권1호
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    • pp.28-33
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    • 2006
  • Optical-fiber sensors have been developed to determine the concentrations of glucose and lactic acid in blood samples. Fluorescence dye [tris(2,2'-biphenyridine)-ruthenium(II)-chloride (RuBPY)] was entrapped by using a silicon to the unclad tip of a glass optic fiber. Enzymes like glucose oxidase (GOD) and lactate oxidase (LOD) have been immobilized by acrylamide resin adhesive, adsorption with zeolite or covalent bonding with aminopropyl-triethoxysilan. The fiber-optic glucose/lactate sensor was then used to analyze the concentrations of glucose and lactate in blood samples. The results were compared with the results of HPLC analysis and their difference was in error by less then 5 %.

MALDI-TOF Analysis of Binding between DNA and Peptides Containing Lysine and Tryptophan

  • Lee, Seonghyun;Choe, Sojeong;Oh, Yeeun;Jo, Kyubong
    • Mass Spectrometry Letters
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    • 제6권3호
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    • pp.80-84
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    • 2015
  • Here, we demonstrate the use of MALDI-TOF as a fast and simple analytical approach to evaluate the DNA-binding capability of various peptides. Specifically, by varying the amino acid sequence of the peptides consisting of lysine (K) and tryptophan (W), we identified peptides with strong DNA-binding capabilities using MALDI-TOF. Mass spectrometric analysis reveals an interesting novel finding that lysine residues show sequence selective preference, which used to be considered as mediator of electrostatic interactions with DNA phosphate backbones. Moreover, tryptophan residues show higher affinity to DNA than lysine residues. Since there are numerous possible combinations to make peptide oligomers, it is valuable to introduce a simple and reliable analytical approach in order to quickly identify DNA-binding peptides.

N-Halamine을 이용한 항균 멤브레인의 특성 (Properties of Antimicrobial Membrane Using an N-Halamine Material)

  • 백지윤;김삼수;이재웅
    • 한국염색가공학회지
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    • 제21권4호
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    • pp.57-62
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    • 2009
  • N-Halamines are compounds which have covalent bonding between nitrogen and halogen. N-Halamine materials possess strong antimicrobial properties against wide spectrum of bacteria. The aim of this study is to prepare N-halamine membranes using m-aramid and poly(vinyl alcohol) (PVA). Surface characteristics using scanning electron microscope (SEM), pore size distribution, liquid permeability and mean pore size were measured to confirm feasibility as membrane. The results indicated that increased PYA portion up to 15% in the m-aramid/PVA blend resulted in improved pore size distribution, liquid permeability as well as mean pore size. Furthermore, antibacterial efficacy of the membranes after chlorination was confirmed and the results showed that bacteria in water were inactivated.

Phonon-Assisted Electron Hopping Conduction in the Uranium Doped One-Dimensional Antiferromagnet Ca2CuO3

  • Thanh, Phung Quoc;Yu, Seong-Cho;Nhat, Hoang-Nam
    • Journal of Magnetics
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    • 제13권4호
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    • pp.132-135
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    • 2008
  • The authors studied the conduction mechanism in an uranium doped low dimensional magnetic system $Ca_2CuO_3$. This system exhibits the S=1/2 quasi 1D antiferromagnetic chains of -Cu-O- with strong magnetic coupling, and demonstrates continuous semiconductor-like behavior with constant covalent insulator character. This paper identifies the conduction is due to thermally activated phonon-assisted electron hopping between dopant uranium sites. The parameter a, the characteristic for hopping probability, was determined to be 0.18 ${\AA}^{-1}$. This value manifests a relatively stronger hopping probability for $Ca_2CuO_3$ as compared with other uranium doped ceramics.

Investigation of the electrode reaction of cytochrome c and pyrroliquinoline quinone at self-assembled monolayers of amino acid

  • Kim Imsook;Kwak Juhyoun
    • 전기화학회지
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    • 제2권1호
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    • pp.27-30
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    • 1999
  • Self-Assembled monolayers of carboxyl-terminated alkanethiols, which is negatively charged in pH 7.0, were usually used to facilitate the electron transfer between the positively charged protein and the electrode. In case of L-cysteine, as it has both positive and negative group, it can be a candidate for a new modifier to facilitate positively charged protein or negatively charged protein. Our investigation of L-cysteine shows that the electron transfer occurs successfully to both cytochrome c (cyt. c) and pyrroloquinoline quinone (PQQ). By using 1-ethyl-3-(3-dime-thlyaminopropyl) carbodiimide (EDC), we made a covalent bond between cyt. c and monolayer. Then PQQ was electrostatically adsorbed to the same monolayer. Cyclic voltammograms show that both molecules do not interfere each other and electron transfer is appreciable.

Functionalization of graphene nanoplatelets using sugar azide for graphene/epoxy nanocomposites

  • Bose, Saswata;Drzal, Lawrence T.
    • Carbon letters
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    • 제16권2호
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    • pp.101-106
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    • 2015
  • We report a covalent functionalization of graphene nanoparticles (GnPs) employing 2,3,4-Tri-O-acetyl-${\beta}$-D-xylopyranosyl azide followed by fabrication of an epoxy/functionalized graphene nanocomposite and an evaluation of its thermo-mechanical performance. Successful functionalization of GnP was confirmed via thermal and spectroscopic study. Raman spectroscopy indicated that the functionalization was on the edge of the graphene sheets; the basal plane was not perturbed as a result of the functionalization. The epoxy/functionalized GnP composite system exhibited an increase in flexural modulus (~18%) and glass transition temperature (${\sim}10^{\circ}C$) compared to an un-functionalized GnP based epoxy composite.

HrSOD-폴리에칠렌 접합체의 아세트아미노펜 간독성에 미치는 영향 (The Effect of Human Recombinant Superoxide Dismutase Conjugated with Polyethylene Glycol on the Hepatic Toxicity of Acetaminophen)

  • 용철순;박경아;오두만
    • Journal of Pharmaceutical Investigation
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    • 제25권4호
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    • pp.313-322
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    • 1995
  • The covalent conjugation of human recombinant superoxide dismutase (hrSOD) with trichloros-triazine activated polyethylene glycol (PEG) 5000 formed soluble conjugates with molecular weight of 92KD, which retained $90{\sim}98%$ of original activity with a markedly prolonged plasma half-life of enzyme activity. The effect of hrSOD-PEG conjugates on acetaminophen (ACP)-induced hepatotoxicity was tested in male rats which were pretreated with 3-methylcholanthrene. HrSOD-PEG conjugates inhibited the hepatotoxicity produced by ACP, on the other hand, native hrSOD had no protective effect. The above results indicated that oxygen radicals might participate in the mechanism of the ACP-induced hepatotoxicity and that polymer conjugated-protein drugs with prolonged half-lives could be employed as an effective therapeutic agent.

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Microfluidic Immunoassay Platform Using Antibody-immobilized Glass Beads and Its Application for Detection of Escherichia coli O157:H7

  • Lee, Nae-Yoon;Yang, Yoon-sun;Kim, Youn-Sang;Park, Sung-su
    • Bulletin of the Korean Chemical Society
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    • 제27권4호
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    • pp.479-483
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    • 2006
  • We developed a microfluidic immunoassay platform for the detection of various analytes such as bacterial pathogen by packing antibody-immobilized glass beads in spatially-isolated microchambers on a microfluidic device. Primary amines of antibody were covalently conjugated to carboxyl-terminated glass beads previously treated with aminosilane followed by glutaraldehyde. Through this covalent binding, up to 905 $\mu$g immunoglobulin G (IgG) per gram of glass beads was immobilized. For application, glass beads attaching antibody specific to Escherichia coli O157:H7, a foodborne pathogen, were packed into a microfluidic device and used for the detection of the serotype. This prototype immunoassay device can be used for the simultaneous detection of multiple analytes by sequentially packing different-sized glass beads attaching different antibody in discrete microchambers on a single microfluidic device.

Synthesis of New Bimetallic Chiral Salen Catalyst Bearing Co(BF4)2 Salt and Its Application in Asymmetric Ring Opening of Epoxide

  • Kim, Yong-Suk;Lee, Choong-Young;Kim, Geon-Joong
    • Bulletin of the Korean Chemical Society
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    • 제31권10호
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    • pp.2973-2979
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    • 2010
  • The newly synthesized homogeneous chiral Co(III) salen complexes were anchored non-covalently on the acidic sites of mesoporous Al-SBA-15. The Bronsted and Lewis acidic sites are attributed to the immobilization of fluorine functionalized chiral salen complexes on the supports. XRD, BET, TEM, FT-IR and ESCA (XPS) analyses were performed to characterize the property of support, and the structure of new homogeneous and heterogeneous chiral Co salen catalyst. The homogeneous and heterogeneous catalysts could be applied in asymmetric ring opening of epichlorohydrine (ECH) by water. They showed very high enantioselectivity and a good yield up to 99% in the catalytic synthesis of optically active products.