Order-disorder-order phase transitions in the clathrate-I Ba8Cu16P30 were induced and controlled by aliovalent substitutions of Zn into the framework. Unaltered Ba8Cu16P30 crystallizes in an ordered orthorhombic (Pbcn) clathrate-I superstructure that maintains complete segregation of metal and phosphorus atoms over 23 different crystallographic positions in the clathrate framework. The driving ...

New highly mixed phases have been identified in Cu/ZnO systems by EXAFS and XANES at both the Cu and Zn K-edge. The phases were generated by ball-milling Cu(2)O/ZnO mixtures under three different atmospheres of synthetic air (SA), SA + CO(2) and CO(2). The system milled in CO(2) shows disproportionation of Cu(2)O into Cu(0), Cu(1+) (cuprite Cu(2)O-type phase) and Cu(2+) (tenorite CuO-type phase...

To assess the impacts of Cu and Zn on fungi, we tested the growth of 18 taxonomically different saprotrophic (basidiomycete, ascomycete and zygomycete) fungi and their production of extracellular oxidative enzymes on Cu(0, 100, 200, 400 mg kg–1) or Zn(0, 100, 200, 400 mg kg–1) containing ABTS (2,2 ́-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) agar plates. Coniothyrium sp. was the most toler...

We identified a Cu-accumulating structure with a dynamic role in intracellular Cu homeostasis. During Zn limitation, Chlamydomonas reinhardtii hyperaccumulates Cu, a process dependent on the nutritional Cu sensor CRR1, but it is functionally Cu deficient. Visualization of intracellular Cu revealed major Cu accumulation sites coincident with electron-dense structures that stained positive for lo...

AIM To assess serum Cu/Zn SOD (Superoxide Dismutase) concentration in individuals with clinical depression. SUBJECTS AND METHODS Serum from 36 individuals diagnosed with clinical depression and 18 healthy controls were tested for Cu/Zn SOD serum concentration using ELISAs. RESULTS Serum Cu/Zn SOD levels of depressed individuals (both with and without secondary anxiety) were significantly hi...

The role of Cu and Zn ions in Alzheimer's disease is linked to the consequences of their coordination to the amyloid-β (Aβ) peptide, i.e. to the modulation of Aβ aggregation and to the production of Reactive Oxygen Species (ROS), two central events of the so-called amyloid cascade. The role of both ions in Aβ aggregation is still controversial. Conversely the higher toxicity of the redox compet...

measurement of availability and mobility of heavy metals in river sediments is required in order to understand the behavior of these metals and to prevent potential toxic hazards. leaching column experiments were conducted for four sediment samples to determine the degree of mobility and the distribution of zn, cd, ni, cu, and pb because of an application of spiked heavy metals in sediments. se...

The effect in vivo of high nutrient levels of copper (240 micromolar) on the activity of different metalloenzymes containing Cu, Mn, Fe, and Zn, distributed in chloroplasts, peroxisomes, and mitochondria, was studied in leaves of two varieties of Pisum sativum L. plants with different sensitivity to copper. The metalloenzymes studied were: cytochrome c oxidase, Mn-superoxide dismutase (Mn-SOD) ...

The role of Cu and Zn ions in Alzheimer’s disease is linked to the consequences of their coordination to the amyloid-β (Aβ) peptide, i.e. to the modulation of Aβ aggregation and to the production of Reactive Oxygen Species (ROS), two central events of the so-called amyloid cascade. The role of both ions in Aβ aggregation is still controversial. Conversely the higher toxicity of the redox compet...