The Experts below are selected from a list of 246 Experts worldwide ranked by ideXlab platform
Philippe Boudeville - One of the best experts on this subject based on the ideXlab platform.
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wet or dry mechanochemical synthesis of calcium phosphates influence of the water content on dcpd cao reaction kinetics
Acta Biomaterialia, 2008Co-Authors: El H Briakbenabdeslam, Michel Vert, Maria-pau Ginebra, Philippe BoudevilleAbstract:Abstract Mechanosynthesis of calcium phosphates can be performed under wet or dry conditions. In most papers and patents, grinding under wet conditions was selected. So far, only a few papers were devoted to dry mechanosynthesis of calcium phosphates. To understand why wet mechanosynthesis was preferred, the influence of water addition on the kinetics of the mechanochemical reaction of dicalcium phosphate dihydrate with calcium oxide was investigated. The DCPD disappearance rate constant k and the final reaction time t f were determined in each case and correlated with the water content present in the slurry. Results showed that the addition water (i) slowed down the reaction rate and (ii) increased the powder contamination by mill material (hard porcelain) due to ball and vial erosion; and that (iii) wet milling did not generate the expected products, in contrast to dry grinding, because porcelain induced hydroxyapatite decomposition with the formation of β-tricalcium phosphate and silicon-stabilized tricalcium phosphate. Consequently, dry mechanosynthesis appears preferable to wet milling in the preparation of calcium phosphates of biological interest.
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Wet or dry mechanochemical synthesis of calcium phosphates? Influence of the water content on DCPD-CaO reaction kinetics.
2008Co-Authors: Hassane E. El Briak-BenAbdeslam, Michel Vert, Maria-pau Ginebra, Philippe BoudevilleAbstract:Mechanosynthesis of calcium phosphates can be performed under wet or dry conditions. In most papers and patents, grinding under wet conditions was selected. So far, only a few papers were devoted to dry mechanosynthesis of calcium phosphates. To understand why wet mechanosynthesis was preferred, the influence of water addition on the kinetics of the mechanochemical reaction of dicalcium phosphate dihydrate with calcium oxide was investigated. The DCPD disappearance rate constant k and the final reaction time t(f) were determined in each case and correlated with the water content present in the slurry. Results showed that the addition water (i) slowed down the reaction rate and (ii) increased the powder contamination by mill material (hard porcelain) due to ball and vial erosion; and that (iii) wet milling did not generate the expected products, in contrast to dry grinding, because porcelain induced hydroxyapatite decomposition with the formation of beta-tricalcium phosphate and silicon-stabilized tricalcium phosphate. Consequently, dry mechanosynthesis appears preferable to wet milling in the preparation of calcium phosphates of biological interest.
Charles A. Brearley - One of the best experts on this subject based on the ideXlab platform.
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simple synthesis of 32p labelled inositol hexakisphosphates for study of phosphate transformations
Plant and Soil, 2018Co-Authors: Hayley Whitfield, Andrew M Riley, Soulla Diogenous, Himali Y Godage, Barry V L Potter, Charles A. BrearleyAbstract:In many soils inositol hexakisphosphate in its various forms is as abundant as inorganic phosphate. The organismal and geochemical processes that exchange phosphate between inositol hexakisphosphate and other pools of soil phosphate are poorly defined, as are the organisms and enzymes involved. We rationalized that simple enzymic synthesis of inositol hexakisphosphate labeled with 32P would greatly enable study of transformation of soil inositol phosphates when combined with robust HPLC separations of different inositol phosphates.
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Synthesis of inositol phosphate ligands of plant hormone-receptor complexes: pathways of inositol hexakisphosphate turnover.
Biochemical Journal, 2012Co-Authors: David E. Hanke, Samuel E. K. Caddick, Paroo N. Parmar, Porntip Green, Charles A. BrearleyAbstract:Reduction of phytate is a major goal of plant breeding programs to improve the nutritional quality of crops. Remarkably, except for the storage organs of crops such as barley, maize and soybean, we know little of the stereoisomeric composition of inositol phosphates in plant tissues. To investigate the metabolic origins of higher inositol phosphates in photosynthetic tissues, we have radiolabelled leaf tissue of Solanum tuberosum with myo -[2- 3 H]inositol, undertaken a detailed analysis of inositol phosphate stereoisomerism and permeabilized mesophyll protoplasts in media containing inositol phosphates. We describe the inositol phosphate composition of leaf tissue and identify pathways of inositol phosphate metabolism that we reveal to be common to other kingdoms. Our results identify the metabolic origins of a number of higher inositol phosphates including ones that are precursors of cofactors, or cofactors of plant hormone–receptor complexes. The present study affords alternative explanations of the effects of disruption of inositol phosphate metabolism reported in other species, and identifies different inositol phosphates from that described in photosynthetic tissue of the monocot Spirodela polyrhiza . We define the pathways of inositol hexakisphosphate turnover and shed light on the occurrence of a number of inositol phosphates identified in animals, for which metabolic origins have not been defined.
G. Bryce Mcgarvey - One of the best experts on this subject based on the ideXlab platform.
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Study of alkyl phosphates in industrial petroleum mixtures by comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry
Analytical and Bioanalytical Chemistry, 2011Co-Authors: James J. Harynuk, Aleisha D. Rossé, G. Bryce McgarveyAbstract:Dialkyl phosphate esters used as gellants in some oil well fracturing processes for conventional oil production can result in contamination of the collected crude. Though the exact mechanism is unclear, such compounds form volatile phosphorus that compromises refinery processes. Our initial research involved producing a comprehensive two-dimensional gas chromatographic method (GC × GC) for the detection and quantification of alkyl phosphate esters in petroleum samples, which surpassed the current method employed in sensitivity and speciation capabilities. However, selective detection is required for such analytes in petroleum matrices. This article describes the application of GC × GC with time-of-flight mass spectrometry for selective detection to the analysis of di- and tri-alkyl phosphates in petroleum samples. Features in the electron impact mass spectra of alkyl phosphates are discussed along with the GC × GC retention characteristics of the compounds. Based on these discussions, a preliminary classification and quantification of alkyl phosphate contamination in a suite of industrial samples is then presented.
El H Briakbenabdeslam - One of the best experts on this subject based on the ideXlab platform.
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wet or dry mechanochemical synthesis of calcium phosphates influence of the water content on dcpd cao reaction kinetics
Acta Biomaterialia, 2008Co-Authors: El H Briakbenabdeslam, Michel Vert, Maria-pau Ginebra, Philippe BoudevilleAbstract:Abstract Mechanosynthesis of calcium phosphates can be performed under wet or dry conditions. In most papers and patents, grinding under wet conditions was selected. So far, only a few papers were devoted to dry mechanosynthesis of calcium phosphates. To understand why wet mechanosynthesis was preferred, the influence of water addition on the kinetics of the mechanochemical reaction of dicalcium phosphate dihydrate with calcium oxide was investigated. The DCPD disappearance rate constant k and the final reaction time t f were determined in each case and correlated with the water content present in the slurry. Results showed that the addition water (i) slowed down the reaction rate and (ii) increased the powder contamination by mill material (hard porcelain) due to ball and vial erosion; and that (iii) wet milling did not generate the expected products, in contrast to dry grinding, because porcelain induced hydroxyapatite decomposition with the formation of β-tricalcium phosphate and silicon-stabilized tricalcium phosphate. Consequently, dry mechanosynthesis appears preferable to wet milling in the preparation of calcium phosphates of biological interest.
Maria-pau Ginebra - One of the best experts on this subject based on the ideXlab platform.
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wet or dry mechanochemical synthesis of calcium phosphates influence of the water content on dcpd cao reaction kinetics
Acta Biomaterialia, 2008Co-Authors: El H Briakbenabdeslam, Michel Vert, Maria-pau Ginebra, Philippe BoudevilleAbstract:Abstract Mechanosynthesis of calcium phosphates can be performed under wet or dry conditions. In most papers and patents, grinding under wet conditions was selected. So far, only a few papers were devoted to dry mechanosynthesis of calcium phosphates. To understand why wet mechanosynthesis was preferred, the influence of water addition on the kinetics of the mechanochemical reaction of dicalcium phosphate dihydrate with calcium oxide was investigated. The DCPD disappearance rate constant k and the final reaction time t f were determined in each case and correlated with the water content present in the slurry. Results showed that the addition water (i) slowed down the reaction rate and (ii) increased the powder contamination by mill material (hard porcelain) due to ball and vial erosion; and that (iii) wet milling did not generate the expected products, in contrast to dry grinding, because porcelain induced hydroxyapatite decomposition with the formation of β-tricalcium phosphate and silicon-stabilized tricalcium phosphate. Consequently, dry mechanosynthesis appears preferable to wet milling in the preparation of calcium phosphates of biological interest.
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Wet or dry mechanochemical synthesis of calcium phosphates? Influence of the water content on DCPD-CaO reaction kinetics.
2008Co-Authors: Hassane E. El Briak-BenAbdeslam, Michel Vert, Maria-pau Ginebra, Philippe BoudevilleAbstract:Mechanosynthesis of calcium phosphates can be performed under wet or dry conditions. In most papers and patents, grinding under wet conditions was selected. So far, only a few papers were devoted to dry mechanosynthesis of calcium phosphates. To understand why wet mechanosynthesis was preferred, the influence of water addition on the kinetics of the mechanochemical reaction of dicalcium phosphate dihydrate with calcium oxide was investigated. The DCPD disappearance rate constant k and the final reaction time t(f) were determined in each case and correlated with the water content present in the slurry. Results showed that the addition water (i) slowed down the reaction rate and (ii) increased the powder contamination by mill material (hard porcelain) due to ball and vial erosion; and that (iii) wet milling did not generate the expected products, in contrast to dry grinding, because porcelain induced hydroxyapatite decomposition with the formation of beta-tricalcium phosphate and silicon-stabilized tricalcium phosphate. Consequently, dry mechanosynthesis appears preferable to wet milling in the preparation of calcium phosphates of biological interest.