The Experts below are selected from a list of 102042 Experts worldwide ranked by ideXlab platform

T. Lakhlifi - One of the best experts on this subject based on the ideXlab platform.

Mohammed Baalousha - One of the best experts on this subject based on the ideXlab platform.

  • physico Chemical Behaviour and algal toxicity of nanoparticulate ceo2 in freshwater
    Environmental Chemistry, 2010
    Co-Authors: Nicola J. Rogers, Natasha M. Franklin, Simon C. Apte, Graeme E. Batley, Brad M. Angel, Jamie R. Lead, Mohammed Baalousha
    Abstract:

    In assessing the risks posed by nanomaterials in the environment, the overriding research challenges are to determine if nanomaterials are more toxic than the bulk forms of the same material, and the extent to which toxicity is governed by particle size and reactivity. In this study, the toxicity of nanoparticulate CeO2 (nominally 10-20 nm) to the freshwater alga Pseudokirchneriella subcapitata was compared to the same material at the micron size (nominally <5 µm). Growth inhibition experiments revealed inhibitory concentration values, giving 50% reduction in algal growth rate after 72 h (IC50), of 10.3 ± 1.7 and 66 ± 22 mg L −1 for the nanoparticles and bulk materials respectively. Cells exposed to CeO2 particles were permeable to the DNA-binding dye SYTOX ® Green in a concentration-dependent manner indicating damage to the cell membrane. Screening assays to assess the oxidative activity of the particles showed that the light illumination conditions used during standard assays are sufficient to stimulate photocatalytic activity of CeO2 particles, causing the generation of hydroxyl radicals and peroxidation of a model plant fatty acid. No oxidative activity or lipid peroxidation was observed in the dark. These findings indicate that inhibitory mode of action of CeO2 to P. subcapitata is mediated by a cell-particle interaction causing membrane damage. The effect is most likely photoChemically induced and is enhanced for the nanoparticulate form of the CeO2.

  • Physico-Chemical Behaviour and algal toxicity of nanoparticulate CeO2 in freshwater
    Environmental Chemistry, 2010
    Co-Authors: Nicola J. Rogers, Natasha M. Franklin, Simon C. Apte, Graeme E. Batley, Brad M. Angel, Jamie R. Lead, Mohammed Baalousha
    Abstract:

    In assessing the risks posed by nanomaterials in the environment, the overriding research challenges are to determine if nanomaterials are more toxic than the bulk forms of the same material, and the extent to which toxicity is governed by particle size and reactivity. In this study, the toxicity of nanoparticulate CeO2 (nominally 10-20 nm) to the freshwater alga Pseudokirchneriella subcapitata was compared to the same material at the micron size (nominally

Britta M Folmer - One of the best experts on this subject based on the ideXlab platform.

Driss Zakarya - One of the best experts on this subject based on the ideXlab platform.

Nicola J. Rogers - One of the best experts on this subject based on the ideXlab platform.

  • physico Chemical Behaviour and algal toxicity of nanoparticulate ceo2 in freshwater
    Environmental Chemistry, 2010
    Co-Authors: Nicola J. Rogers, Natasha M. Franklin, Simon C. Apte, Graeme E. Batley, Brad M. Angel, Jamie R. Lead, Mohammed Baalousha
    Abstract:

    In assessing the risks posed by nanomaterials in the environment, the overriding research challenges are to determine if nanomaterials are more toxic than the bulk forms of the same material, and the extent to which toxicity is governed by particle size and reactivity. In this study, the toxicity of nanoparticulate CeO2 (nominally 10-20 nm) to the freshwater alga Pseudokirchneriella subcapitata was compared to the same material at the micron size (nominally <5 µm). Growth inhibition experiments revealed inhibitory concentration values, giving 50% reduction in algal growth rate after 72 h (IC50), of 10.3 ± 1.7 and 66 ± 22 mg L −1 for the nanoparticles and bulk materials respectively. Cells exposed to CeO2 particles were permeable to the DNA-binding dye SYTOX ® Green in a concentration-dependent manner indicating damage to the cell membrane. Screening assays to assess the oxidative activity of the particles showed that the light illumination conditions used during standard assays are sufficient to stimulate photocatalytic activity of CeO2 particles, causing the generation of hydroxyl radicals and peroxidation of a model plant fatty acid. No oxidative activity or lipid peroxidation was observed in the dark. These findings indicate that inhibitory mode of action of CeO2 to P. subcapitata is mediated by a cell-particle interaction causing membrane damage. The effect is most likely photoChemically induced and is enhanced for the nanoparticulate form of the CeO2.

  • Physico-Chemical Behaviour and algal toxicity of nanoparticulate CeO2 in freshwater
    Environmental Chemistry, 2010
    Co-Authors: Nicola J. Rogers, Natasha M. Franklin, Simon C. Apte, Graeme E. Batley, Brad M. Angel, Jamie R. Lead, Mohammed Baalousha
    Abstract:

    In assessing the risks posed by nanomaterials in the environment, the overriding research challenges are to determine if nanomaterials are more toxic than the bulk forms of the same material, and the extent to which toxicity is governed by particle size and reactivity. In this study, the toxicity of nanoparticulate CeO2 (nominally 10-20 nm) to the freshwater alga Pseudokirchneriella subcapitata was compared to the same material at the micron size (nominally