Mineral Based Activities
Mostrando 13-18 de 18 artigos, teses e dissertações.
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13. Effects of phosphorylation of chrysotile on pleuropulmonary fibrogenicity and carcinogenicity.
As well as fibre size, fibre chemistry is a determinant of toxicity of mineral fibres. On these grounds, a few years ago, the asbestos industry in Québec developed a process to modify the surface chemistry of chrysotile asbestos by fixing phosphorous atoms. The pleuropulmonary fibrogenicity and carcinogenicity of the native and surface treated chrysotile, c
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14. Physical activity, calcium intake, and bone mineral content in children in The Netherlands.
STUDY OBJECTIVE--To examine the relation between physical activity, calcium intake, and bone mineral content in children. DESIGN--Population based, cross sectional study. SETTING--Primary schools in Zoetermeer, The Netherlands. PARTICIPANTS--Altogether 1359 Dutch boys and girls, aged 7 to 11 years (response rate 88%). MEASUREMENTS--Bone mineral content was m
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15. Characterization of Azo Reduction Activity in a Novel Ascomycete Yeast Strain
Several model azo dyes are reductively cleaved by growing cultures of an ascomycete yeast species, Issatchenkia occidentalis. In liquid media containing 0.2 mM dye and 2% glucose in a mineral salts base, more than 80% of the dyes are removed in 15 h, essentially under microaerophilic conditions. Under anoxic conditions, decolorization does not occur, even in
American Society for Microbiology.
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16. Transition of Chemolithotroph Ferrobacillus ferrooxidans to Obligate Organotrophy and Metabolic Capabilities of Glucose-Grown Cells
Transition of chemolithotrophic Ferrobacillus ferrooxidans to organotrophy occurred after 60 hr of incubation in an organic medium. Three distinct phases, based on metabolic activities of cells, were observed during the course of transition. Conversion of cellular nutrition to organotrophy resulted in a gradual loss of Fe2+ oxidation and cessation of CO2 fix
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17. Catabolite-mediated mutations in alternate toluene degradative pathways in Pseudomonas putida.
Pseudomonas putida 54g grew on mineral salts with toluene and exhibited catechol-2,3-dioxygenase (C23O) activity, indicating a meta pathway. After 10 to 15 days on toluene, nondegrading (Tol-) variants approached nearly 10% of total CFU. Auxotrophs were not detected among variants, suggesting selective loss of catabolic function(s). Variant formation was sub
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18. In vitro synthesis of 1 alpha,25-dihydroxycholecalciferol and 24,25-dihydroxycholecalciferol by isolated calvarial cells.
The question of whether the skeleton metabolizes 25-hydroxycholecalciferol [25(OH)D3] to more-polar products was studied. Calvarial cells were dispersed from 16-day old chicken embryos by using collagenase and then grown in culture in serum-free medium. Confluent cell cultures were incubated with 7 nM 25(OH)[3H]D3 for 2 hr, and the vitamin D metabolites were