Increasing Concentration Of Copper Ions Research Articles

Triticale doubled haploid plant regeneration factors linked by structural equation modeling

Triticale regeneration via anther culture faces many difficulties, e.g., a low percentage of regenerated plants and the presence of albinos. Plant regeneration may be affected by abiotic stresses and by ingredients added to the induction medium. The latter influences biochemical pathways and plant regeneration efficiency. Among such ingredients, copper and silver ions acting as cofactors for enzymatic reactions are of interest. However, their role in plant tissue cultures and relationships with biochemical pathways has not been studied yet.The study evaluated relationships between DNA methylation, changes in DNA sequence variation, and green plant regeneration efficiency influenced by copper and silver ions during triticale plant regeneration. For this purpose, a biological model based on donor plants and their regenerants, a methylation-sensitive amplified fragment length polymorphism, and structural equation modeling were employed.The green plant regeneration efficiency varied from 0.71 to 6.06 green plants per 100 plated anthers. The values for the components of tissue culture-induced variation related to cytosine methylation in a CHH sequence context (where H is A, C, or T) were 8.65% for sequence variation, 0.76% for DNA demethylation, and 0.58% for de novo methylation. The proposed model states that copper ions affect the regeneration efficiency through cytosine methylation and may induce mutations through, e.g., oxidative processes, which may interfere with the green plant regeneration efficiency. The linear regression confirms that the plant regeneration efficiency rises with increasing copper ion concentration in the absence of Ag ions in the induction medium. The least absolute shrinkage and selection operator regression shows that de novo methylation, demethylation, and copper ions may be involved in the green plant regeneration efficiency. According to structural equation modeling, copper ions play a central role in the model determining the regeneration efficiency.

Effect of copper additive on microstructure and anti-corrosion performance of black MAO films grown on AZ91 alloy and coloration mechanism

Black micro-arc oxidation (MAO) films on AZ91 alloy were successfully fabricated using MAO technique in a designed bath of silicate electrolyte with addition of colorant copper additive aiming to extend the application scope of magnesium and its alloys. It was found that the color of MAO films on AZ91 alloy changed gradually from white to black with the increasing copper ion concentration. The black color MAO films formed on AZ91 alloy may mainly be owing to the existence of CuO particulates in the porous outer layer. In addition, incorporation of CuO in the uniform and compact MAO films could significantly improve the anti-corrosion property of AZ91 substrate, thus effectively prevent the inward migration of corrosive medium. Copper additive concentration of electrolyte also affected the surface roughness of MAO films. The increase of copper additive concentration may result in an increase in the thickness and compactness of the black MAO films, and finally an enhancement in their corrosion resistance. Therefore, the MAO technique method coupled with silicate electrolyte containing copper additive was a promising surface modification technique for magnesium alloys.

구리이온을 함유한 PCB 폐에칭액의 Cross-flow 나노여과

In this study the nanofiltration (NF) membrane treatment of a sulfuric acid waste solutions containing copper ion () discharging from the etching processes of the printed circuit board (PCB) manufacturing industry has been studied for the recycling of acid etching solution. SelRO MPS-34 4040 NF membrane from Koch company was tested to obtain the basic NF data for recycling of etching solution and separation efficiency (total rejection) of copper ion. NF experiments were carried out with a cross-flow membrane filtration laboratory system. The permeate flux was decreased with the increasing copper ion concentration in sulfuric acid solution and lowering pH of acid solution, and its value was the range of . Total rejection of copper ion was decreased with the increasing copper ion concentration, lowering pH of acid solution and decreasing cross-flow rate. The total rejection of copper ion was more than 70% at the experimental condition. The SelRO MPS-34 4040 NF membrane was represented the stable flux and rejection for 1 year operation.

Intensification of the rate of heavy metal removal from wastewater by cementation in a jet reactor

Removal of copper by cementation on zinc disc from dilute copper sulfate solution in a recirculating batch reactor which consisted of a horizontal zinc disc impinged by an axial turbulent submerged jet was studied. The effect of different parameters such as, initial copper ion concentration, solution flow rate and the axial distance between the zinc disk and submerged jet on the rate of copper ion removal were investigated. The rate of cementation was found to increase with increasing solution flow rate, decreasing the axial distance between jet and zinc disc, and by increasing copper ion concentration. The rate of diffusion controlled cementation of copper ion was expressed in terms of the mass transfer coefficient, the data were correlated with the following dimensionless correlation: Sh = 0.306 S c 0.33 Re 0.997 ( d n / l ) 0.0337 . The high rate of mass transfer of the jet reactor, qualifies the reactor for diffusion controlled heavy metals removal from wastewater.

Prevention of Phytophthora root rot in Gerbera by increasing copper ion concentration in the nutrient solution

Increased copper concentration in the nutrient solution was used as a means for reducing the severity of root rot caused by Phytophthora cryptogea in Gerbera jamesonii in three experiments. Plants were grown in pots on ebb-and-flow benches with separate systems for recirculating nutrient solutions. Eight nutrient solutions with two concentrations of copper ions (0.07 and 0.28 ppm), two electrical conductivity values (1.5 and 2.2 mScm-1), and two iron sources (FeHEEDTA or FeSO4) were combined in a factorial design. Plants were inoculated with zoospores of P. cryptogea via the recirculating nutrient solution. Disease incidence was significantly reduced in inoculated plants grown on nutrient solution with 0.28 ppm copper compared with 0.07 ppm copper, when FeSO4was introduced as the iron source. No effects of increased copper concentration was observed when iron was added as FeHEEDTA. The change in electrical conductivity from 1.5 to 2.2 mScm-1 without changing the Cu2+ concentration did not influence the disease severity in these experiments. The results suggest that increased copper ion concentration in the nutrient solution could be a component of disease management strategy for ebb-and-flow systems. Possible management of the cupric ion concentration in the nutrient solutions is discussed.

57Fe-Mössbauer studies of the CuxFe3−xO4 spinel system

Mössbauer spectroscopy has been used to examine the effect of increasing copper ion concentration on the iron distribution in CuxFe3−xO4(0⩽x⩽0.9). For x⩽0.37, fast electron exchange among octahedral iron ions occurs as in Fe3O4, suggesting that the itinerant electrons associated with the octahedral Fe2+ ions remain delocalized in the sublattice. At high values of x (x⩾0.59), however, the itinerant electrons become localized in a small fraction of exchange-coupled iron ions. The relative numbers of distinguishable cations making up the complements of the octahedral sites of the copper ferrites are determined.

Copper ion binding and heparin interactions of human fibrinogen.

AbstractThe binding of copper ions to fibrinogen was studied by the equilibrium dialysis technique in neutral Tris buffer. The presence of copper causes precipitation of fibrinogen‐copper complexes, the amount of which varies with the copper ion concentration. Solutions of 96% clottable fibrinogen (whole fibrinogen) displayed a maximum binding capacity about four times greater than that of fibrinogen solutions from which the cold‐insoluble precipitate had been removed (cold‐soluble fibrinogen). Binding in both systems apparently involves two classes of sites in fibrinogen, and the class of lower affinity is associated with cooperative interactions with copper. The copper concentration at which this cooperative uptake occurs is identical to the concentration at which the amount of precipitated material increases sharply and also to the concentration at which a sharp decrease is observed in the sedimentation coefficient of soluble fibrinogen, suggesting some relationship between copper binding, solubility, and solution properties.The presence of heparin markedly affects the sedimentation coefficient of fibrinogen in the presence of copper ions, although showing a lesser effect in the absence of the metal. The sedimentation coefficient of fibrinogen is increased in the presence of heparin and copper ion, compared to the value of fibrinogen‐copper systems without heparin, and this effect is enhanced by changing the fibrinogen:heparin molar ratio to larger values. The precipitation of fibrinogen from solution, apparently without a coincident removal of heparin, also increases with increasing copper ion concentration and fibrinogen:heparin molar ratio. The possible significance of these effects in terms of heparin anti‐coagulant activity is discussed.