The Experts below are selected from a list of 4743 Experts worldwide ranked by ideXlab platform

Robert G Arnold - One of the best experts on this subject based on the ideXlab platform.

  • applications of a colorimetric plate assay for soluble methane monooxygenase activity
    Applied and Environmental Microbiology, 1992
    Co-Authors: David W Graham, D G Korich, R P Leblanc, Norval A Sinclair, Robert G Arnold
    Abstract:

    A straightforward method is described for screening methanotrophic colonies for soluble methane monooxygenase (sMMO) activity on solid media. Such activity results in the development of a colored complex between 1-naphthol, which is formed when sMMO reacts with naphthalene, and o-Dianisidine (tetrazotized). Methanotrophic colonies expressing sMMO turned deep purple when exposed successively to naphthalene and o-Dianisidine. The method was evaluated within the contexts of two potential applications. The first was for the enumeration of Methylosinus trichosporium OB3b in a methane-amended, unsaturated soil column dedicated to vinyl chloride treatment. The second application was for the isolation and enumeration of sMMO-bearing methanotrophs from sanitary landfill soils. The technique was effective in both applications. Images

  • Applications of a colorimetric plate assay for soluble methane monooxygenase activity.
    Applied and environmental microbiology, 1992
    Co-Authors: David W Graham, D G Korich, R P Leblanc, Norval A Sinclair, Robert G Arnold
    Abstract:

    A straightforward method is described for screening methanotrophic colonies for soluble methane monooxygenase (sMMO) activity on solid media. Such activity results in the development of a colored complex between 1-naphthol, which is formed when sMMO reacts with naphthalene, and o-Dianisidine (tetrazotized). Methanotrophic colonies expressing sMMO turned deep purple when exposed successively to naphthalene and o-Dianisidine. The method was evaluated within the contexts of two potential applications. The first was for the enumeration of Methylosinus trichosporium OB3b in a methane-amended, unsaturated soil column dedicated to vinyl chloride treatment. The second application was for the isolation and enumeration of sMMO-bearing methanotrophs from sanitary landfill soils. The technique was effective in both applications.

Roberto H. Nussenzveig - One of the best experts on this subject based on the ideXlab platform.

  • the salivary catechol oxidase peroxidase activities of the mosquito anopheles albimanus
    The Journal of Experimental Biology, 1993
    Co-Authors: José M. C. Ribeiro, Roberto H. Nussenzveig
    Abstract:

    Salivary gland homogenates from adult female Anopheles albimanus mosquitoes relaxed aortic rings preconstricted with noradrenaline (NA). This relaxation is slow and is due to destruction of NA. Incubation of NA with the homogenate yielded a product with a spectrum consistent with the corresponding adrenochrome. Oxidation of NA was enhanced by a superoxide generation system and inhibited by the combined action of superoxide dismutase and catalase. Additionally, peroxidase activity on both synthetic (o-Dianisidine) and biologically active (serotonin) substrates was also present in the salivary gland homogenates, this latter activity requiring hydrogen peroxide. Noradrenaline oxidation, serotonin and o-Dianisidine peroxidation and vasodilation all co-elute with a heme protein of relative molecular mass 50,000, as determined by molecular sieving chromatography. Peroxidase activity was localized in the posterior (female-specific) lobes of salivary glands and was also detected in nitrocellulose membranes probed by hungry mosquitoes. Protein and peroxidase activities were significantly lower in salivary glands of mosquitoes after probing and feeding on blood. It is suggested that adult female Anopheles albimanus mosquitoes contain a salivary heme peroxidase that functions during blood finding and blood feeding by destroying hemostatically active biogenic amines released by the vertebrate host during tissue destruction.

  • The salivary catechol oxidase/peroxidase activities of the mosquito Anopheles albimanus
    The Journal of experimental biology, 1993
    Co-Authors: José M. C. Ribeiro, Roberto H. Nussenzveig
    Abstract:

    Salivary gland homogenates from adult female Anopheles albimanus mosquitoes relaxed aortic rings preconstricted with noradrenaline (NA). This relaxation is slow and is due to destruction of NA. Incubation of NA with the homogenate yielded a product with a spectrum consistent with the corresponding adrenochrome. Oxidation of NA was enhanced by a superoxide generation system and inhibited by the combined action of superoxide dismutase and catalase. Additionally, peroxidase activity on both synthetic (o-Dianisidine) and biologically active (serotonin) substrates was also present in the salivary gland homogenates, this latter activity requiring hydrogen peroxide. Noradrenaline oxidation, serotonin and o-Dianisidine peroxidation and vasodilation all co-elute with a heme protein of relative molecular mass 50,000, as determined by molecular sieving chromatography. Peroxidase activity was localized in the posterior (female-specific) lobes of salivary glands and was also detected in nitrocellulose membranes probed by hungry mosquitoes. Protein and peroxidase activities were significantly lower in salivary glands of mosquitoes after probing and feeding on blood. It is suggested that adult female Anopheles albimanus mosquitoes contain a salivary heme peroxidase that functions during blood finding and blood feeding by destroying hemostatically active biogenic amines released by the vertebrate host during tissue destruction.

David W Graham - One of the best experts on this subject based on the ideXlab platform.

  • applications of a colorimetric plate assay for soluble methane monooxygenase activity
    Applied and Environmental Microbiology, 1992
    Co-Authors: David W Graham, D G Korich, R P Leblanc, Norval A Sinclair, Robert G Arnold
    Abstract:

    A straightforward method is described for screening methanotrophic colonies for soluble methane monooxygenase (sMMO) activity on solid media. Such activity results in the development of a colored complex between 1-naphthol, which is formed when sMMO reacts with naphthalene, and o-Dianisidine (tetrazotized). Methanotrophic colonies expressing sMMO turned deep purple when exposed successively to naphthalene and o-Dianisidine. The method was evaluated within the contexts of two potential applications. The first was for the enumeration of Methylosinus trichosporium OB3b in a methane-amended, unsaturated soil column dedicated to vinyl chloride treatment. The second application was for the isolation and enumeration of sMMO-bearing methanotrophs from sanitary landfill soils. The technique was effective in both applications. Images

  • Applications of a colorimetric plate assay for soluble methane monooxygenase activity.
    Applied and environmental microbiology, 1992
    Co-Authors: David W Graham, D G Korich, R P Leblanc, Norval A Sinclair, Robert G Arnold
    Abstract:

    A straightforward method is described for screening methanotrophic colonies for soluble methane monooxygenase (sMMO) activity on solid media. Such activity results in the development of a colored complex between 1-naphthol, which is formed when sMMO reacts with naphthalene, and o-Dianisidine (tetrazotized). Methanotrophic colonies expressing sMMO turned deep purple when exposed successively to naphthalene and o-Dianisidine. The method was evaluated within the contexts of two potential applications. The first was for the enumeration of Methylosinus trichosporium OB3b in a methane-amended, unsaturated soil column dedicated to vinyl chloride treatment. The second application was for the isolation and enumeration of sMMO-bearing methanotrophs from sanitary landfill soils. The technique was effective in both applications.

José M. C. Ribeiro - One of the best experts on this subject based on the ideXlab platform.

  • the salivary catechol oxidase peroxidase activities of the mosquito anopheles albimanus
    The Journal of Experimental Biology, 1993
    Co-Authors: José M. C. Ribeiro, Roberto H. Nussenzveig
    Abstract:

    Salivary gland homogenates from adult female Anopheles albimanus mosquitoes relaxed aortic rings preconstricted with noradrenaline (NA). This relaxation is slow and is due to destruction of NA. Incubation of NA with the homogenate yielded a product with a spectrum consistent with the corresponding adrenochrome. Oxidation of NA was enhanced by a superoxide generation system and inhibited by the combined action of superoxide dismutase and catalase. Additionally, peroxidase activity on both synthetic (o-Dianisidine) and biologically active (serotonin) substrates was also present in the salivary gland homogenates, this latter activity requiring hydrogen peroxide. Noradrenaline oxidation, serotonin and o-Dianisidine peroxidation and vasodilation all co-elute with a heme protein of relative molecular mass 50,000, as determined by molecular sieving chromatography. Peroxidase activity was localized in the posterior (female-specific) lobes of salivary glands and was also detected in nitrocellulose membranes probed by hungry mosquitoes. Protein and peroxidase activities were significantly lower in salivary glands of mosquitoes after probing and feeding on blood. It is suggested that adult female Anopheles albimanus mosquitoes contain a salivary heme peroxidase that functions during blood finding and blood feeding by destroying hemostatically active biogenic amines released by the vertebrate host during tissue destruction.

  • The salivary catechol oxidase/peroxidase activities of the mosquito Anopheles albimanus
    The Journal of experimental biology, 1993
    Co-Authors: José M. C. Ribeiro, Roberto H. Nussenzveig
    Abstract:

    Salivary gland homogenates from adult female Anopheles albimanus mosquitoes relaxed aortic rings preconstricted with noradrenaline (NA). This relaxation is slow and is due to destruction of NA. Incubation of NA with the homogenate yielded a product with a spectrum consistent with the corresponding adrenochrome. Oxidation of NA was enhanced by a superoxide generation system and inhibited by the combined action of superoxide dismutase and catalase. Additionally, peroxidase activity on both synthetic (o-Dianisidine) and biologically active (serotonin) substrates was also present in the salivary gland homogenates, this latter activity requiring hydrogen peroxide. Noradrenaline oxidation, serotonin and o-Dianisidine peroxidation and vasodilation all co-elute with a heme protein of relative molecular mass 50,000, as determined by molecular sieving chromatography. Peroxidase activity was localized in the posterior (female-specific) lobes of salivary glands and was also detected in nitrocellulose membranes probed by hungry mosquitoes. Protein and peroxidase activities were significantly lower in salivary glands of mosquitoes after probing and feeding on blood. It is suggested that adult female Anopheles albimanus mosquitoes contain a salivary heme peroxidase that functions during blood finding and blood feeding by destroying hemostatically active biogenic amines released by the vertebrate host during tissue destruction.

Regina C.c.p. Moran - One of the best experts on this subject based on the ideXlab platform.

  • Application of the split-plot experimental design for the optimization of a catalytic procedure for the determination of Cr(VI)
    Analytica Chimica Acta, 1998
    Co-Authors: Cesar Reis, João Carlos De Andrade, Roy E. Bruns, Regina C.c.p. Moran
    Abstract:

    Abstract A kinetic catalytic procedure for the determination of Cr(VI), based on the o-Dianisidine oxidation reaction with hydrogen peroxide in a weakly acid medium was optimized with respect to both reactants [HCl, o-Dianisidine and H2O2] and solvent composition [mixtures of water, acetone and N, N-dimethylformamide], in order to achieve higher sensitivities. This was accomplished by making use of a split-plot experimental design which permitted simultaneous variations in both mixture and process variables, using a response surface approach. Ten mixture experiments were randomized at each one of the 23 factorial levels and error analysis was performed using a split-plot approach. The optimal mixture [water–acetone 70–30% m/m] and process variables [HCl: 6.0×10−4 mol/l, o-Dianisidine: 1.9×10−2 mol/l and H2O2: 0.79 mol/l] values resulted in a significant sensitivity increase compared with a similar procedure described in the literature.