Browsing by Subject "cadmium"
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- ItemOpen AccessA study of the biochemical changes which occur in experimental cadmium poisoning(1965) Gain, Adrian ConalCertain of these isotopes appear suitable for activation analysis by neutron or other type of bombardment, which, in the future, could provide a much more sensitive technique for determination of trace quantities of the element than the spectrographic or oolorimetrio methods currently employed. The metal tarnishes in air and burns when heated forming the oxide. It occurs naturally in small quantities associated with sine, and was discovered by Strongmeyer in 1817 as an impurity in zinc carbonate. Cadmium volatilizes before zinc during the course of preparation of the metal, and condenses as a brown oxide, which is then reduced with carbon. It forms a number of salts, the chloride and sulfate being readily available in high degree of purity.
- ItemOpen AccessA study of the nature and origin of the minialbumins to be found in cadmium-poisoned animals(1967) Sutherland, Elizabeth Mary; Kench, J ECadmium, one of the trace metals, has, in the last two to three decades, become increasingly important in both industrial and biological fields. The recognition of cadmium as a serious health hazard has led to a closer examination of its properties and biochemical effects. Cadmium, an element of ata:nic number 48, atomic weight 112.41 and valency 2, is a soft 'White lustrous metal belonging to the second sub-group of the Periodic Table. It has a boiling point of 768°c, melting point of 321°0, is remarkably volatile for a heavy metal, and exists naturaly as a mixture of eight isotopes, constituting 2 x 10-5% of the earth's crust. Extraction of cadmium is by distillation from zinc ores. The electron configuration of cadmium is 4d105s2, and it forms simple bipositive cations only. There are no ligand field stabilization effects in cadmium ions, and the stereochemistry is, therefore, determined solely by size and electrostatic and covalent bonding forces.s Cadmium chloride shows octahedral co-ordination.
- ItemOpen AccessEffect of selenium on cadmium-induced oxidative stress and esterase activity in rat organs(2013) Dzobo, Kevin; Naik, Yogeshkumar VMetal toxicity is a threat mainly in the industrialised world where industry discharges many toxic metals into the environment. We investigated the effects of two metals - cadmium and selenium - on the cytosolic antioxidant enzymes and esterases in the liver, kidneys and testes of rats. Male Sprague-Dawley rats( N =28) were divided equally into four groups: control, cadmium, selenium and cadmium/selenium. Salts of the metals were administered intraperitoneally for 15 days. In the liver, cadmium treatment (1.67 mg/kg per day) resulted in a decrease in catalase activity and an increase superoxide dismutase (SOD) activity. Selenium treatment (0.23 mg/kg per day) resulted in increases in glutathione s-transferase, catalase and DT-diaphorase activities. Treatment with both cadmium and selenium resulted in an increase in glutathione peroxidase (GPx) activity. Esterase activities were significantly lower in the presence of cadmium. In the kidney, cadmium treatment caused a decrease in catalase, DT-diaphorase, and SOD activities and selenium supplementation reversed the cadmium-induced decrease in these enzyme activities. Selenium treatment increased catalase and SOD activities in the kidney. In the testis, cadmium treatment decreased GPx and SOD activities, but at the same time increased catalase and DT-diaphorase activities. Esterase activities increased in the presence of selenium in both the kidney and testis. These results suggest that selenium might be toxic to the liver while at the same time play a protective role against cadmium-induced oxidative stress and toxicity in the kidney and testis.
- ItemRestrictedEffects of the metal pollutants cadmium and nickel on soybean seed development(Cambridge University Press, 1998) Malan, H; Farrant, JThe chloride salts of Cd or Ni were added to the nutrient solution in which soybean (Glycine max) plants were grown and the response of the plants to these pollutants examined. Both metals markedly reduced plant biomass and seed production. Accumulation was mostly in the roots. Nickel was more mobile than Cd, reaching higher levels in all plant parts, especially seeds. Within the tissues of mature seeds, the highest concentrations of Ni were found in the axis and testa. The highest concentrations of Cd were in the testa and cotyledon, and the lowest in the axis. When expressed on a per seed basis, metal contents of these organs increased with developmental age. Nickel amounts were lower in the pods than the seeds for all growth stages, however there was no significant difference for Cd. Cadmium reduced mature seed mass. This effect was mostly due to decreased yields of lipids, protein and carbohydrates. Although the number of seeds per pod declined as a response to Ni, seed mass was unaffected and there was no apparent effect on storage reserves.