Synthesis of Bilayer Graphene on 90/10 Copper (Cu)/Nickel (Ni) Alloy and Transfer by Electrochemical Delamination

DTIC Science & Technology

2017-09-01

C) and slow decomposition rate in methane (CH4).11 Cu alone has sometimes been shown to form incomplete bilayers with a significant fraction of...argon BLG bilayer graphene C carbon CH4 methane Cu2O cuprous oxide Cu copper CVD chemical vapor deposition DI deionized FeCl3 iron

Effect of calcination temperature on phase transformation and crystallite size of copper oxide (CuO) powders

NASA Astrophysics Data System (ADS)

Ratnawulan, Fauzi, Ahmad; AE, Sukma Hayati

2017-08-01

Copper oxide powder was prepared from Copper iron from South Solok, Indonesia. The samples was dried and calcined for an hour at temperatures of 145°C, 300°C,850°C, 1000°C. Phase transformation and crystallite size of the calcined powders have been investigated as a function of calcination temperature by room-temperature X-ray diffraction (XRD). It was seen that the tenorite, CuO was successfully obtained. With increasing calcining temperature, CuO transformed from malachite Cu2(CO3)(OH)2 to tenorite phase (CuO) and crystallite size of prepared samples increased from 36 nm to 76 nm.

A chemical potentiator of copper-accumulation used to investigate the iron-regulons of Saccharomyces cerevisiae.

PubMed

Foster, Andrew W; Dainty, Samantha J; Patterson, Carl J; Pohl, Ehmke; Blackburn, Hannah; Wilson, Clare; Hess, Corinna R; Rutherford, Julian C; Quaranta, Laura; Corran, Andy; Robinson, Nigel J

2014-07-01

The extreme resistance of Saccharomyces cerevisiae to copper is overcome by 2-(6-benzyl-2-pyridyl)quinazoline (BPQ), providing a chemical-biology tool which has been exploited in two lines of discovery. First, BPQ is shown to form a red (BPQ)2 Cu(I) complex and promote Ctr1-independent copper-accumulation in whole cells and in mitochondria isolated from treated cells. Multiple phenotypes, including loss of aconitase activity, are consistent with copper-BPQ mediated damage to mitochondrial iron-sulphur clusters. Thus, a biochemical basis of copper-toxicity in S. cerevisiae is analogous to other organisms. Second, iron regulons controlled by Aft1/2, Cth2 and Yap5 that respond to mitochondrial iron-sulphur cluster status are modulated by copper-BPQ causing iron hyper-accumulation via upregulated iron-import. Comparison of copper-BPQ treated, untreated and copper-only treated wild-type and fra2Δ by RNA-seq has uncovered a new candidate Aft1 target-gene (LSO1) and paralogous non-target (LSO2), plus nine putative Cth2 target-transcripts. Two lines of evidence confirm that Fra2 dominates basal repression of the Aft1/2 regulons in iron-replete cultures. Fra2-independent control of these regulons is also observed but CTH2 itself appears to be atypically Fra2-dependent. However, control of Cth2-target transcripts which is independent of CTH2 transcript abundance or of Fra2, is also quantified. Use of copper-BPQ supports a substantial contribution of metabolite repression to iron-regulation. © 2014 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd.

Highly efficient Cu-decorated iron oxide nanocatalyst for low pressure CO 2 conversion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halder, Avik; Kilianová, Martina; Yang, Bing

We report a nanoparticulate iron oxide based catalyst for CO2 conversion with high efficiency at low pressures and on the effect of the presence of copper on the catalyst's restructuring and its catalytic performance. In situ X-ray scattering reveals the restructuring of the catalyst at the nanometer scale. In situ X-ray absorption near edge structure (XANES) shows the evolution of the composition and oxidation state of the iron and copper components under reaction conditions along with the promotional effect of copper on the chemical transformation of the iron component. X-ray diffraction (XRD), XANES and Raman spectroscopy proved that the startingmore » nano catalyst is composed of iron oxides differing in chemical nature (alpha-Fe2O3, Fe3O4, FeO(OH)) and dimensionality, while the catalyst after CO2 conversion was identified as a mixture of alpha-Fe, Fe3C, and traces of Fe5C2. The significant increase of the rate CO2 is turned over in the presence of copper nanoparticles indicates that Cu nanoparticles activate hydrogen, which after spilling over to the neighbouring iron sites, facilitate a more efficient conversion of carbon dioxide.« less

Separation of copper ions from iron ions using PVA-g-(acrylic acid/N-vinyl imidazole) membranes prepared by radiation-induced grafting.

PubMed

Ajji, Zaki; Ali, Ali M

2010-01-15

Acrylic acid (AAc), N-vinyl imidazole (Azol) and their binary mixtures were graft copolymerized onto poly(vinyl alcohol) membranes using gamma irradiation. The ability of the grafted membranes to separate Cu ions from Fe ions was investigated with respect to the grafting yield and the pH of the feed solution. The data showed that the diffusion of copper ions from the feed compartment to the receiver compartment depends on the grafting yield of the membranes and the pH of the feed solution. To the contrary, iron ions did not diffuse through the membranes of all grafting yields. However, a limited amount of iron ions diffused in strong acidic medium. This study shows that the prepared membranes could be considered for the separation of copper ions from iron ions. The temperature of thermal decomposition of pure PVA-g-AAc/Azol membrane, PVA-g-AAc/Azol membrane containing copper ions, and PVA-g-AAc/Azol membrane containing iron ions were determined using TGA analyzer. It was shown that the presence of Cu and Fe ions increases the decomposition temperature, and the membranes bonded with iron ions are more stable than those containing copper ions.

[Interaction among the trace elements zinc, copper and iron after depletion and repletion of dairy cows with zinc].

PubMed

Kirchgessner, M; Schwarz, F J; Roth, H P; Schwarz, W A

1978-12-01

Imbalances in the supply with trace elements may be caused by the excessive administration of one or several elements or the insufficient administration in relation to other trace elements. This article deals with the interactions between the trace elements zinc and copper resp. zinc and iron under the conditions of the insufficient supply with Zn (6 mg per kg dry matter of the fodder) and the supply according to the demand with other trace elements (14 mg copper resp. 83 mg iron per dry matter of the fodder). For this purpose we investigated the copper, iron and zinc content of the milk and the serum of cows that were first depleted of zinc through a semi-synthetic zinc deficiency diet and then repleted with extra allowances of zinc. The closest connections exist between the copper and zinc content of the milk. Thus extreme Zn-deficiency feeding conditions the decreased Zn-content on the one hand and increased Cu-content on the other. In contrast to this, the cows' Zn-excretion in the milk increases after Zn-repletion whereas the Cu-content decreases. This shows a distinctly negative correlation. A loose connection could only be detected for the Cu- and Zn-content of the serum. Though the Zn-content changed considerably in dependence on the Zn-supply, the Cu-content remained largely uninfluenced. The Fe-content of both milk and serum shows no interaction with the nutritive Zn-supply. Only after 19 test weeks of extreme Zn-deficiency could a slight increase of the Fe-concentration be indicated.

A chemical potentiator of copper-accumulation used to investigate the iron-regulons of Saccharomyces cerevisiae

PubMed Central

Foster, Andrew W; Dainty, Samantha J; Patterson, Carl J; Pohl, Ehmke; Blackburn, Hannah; Wilson, Clare; Hess, Corinna R; Rutherford, Julian C; Quaranta, Laura; Corran, Andy; Robinson, Nigel J

2014-01-01

The extreme resistance of Saccharomyces cerevisiae to copper is overcome by 2-(6-benzyl-2-pyridyl)quinazoline (BPQ), providing a chemical-biology tool which has been exploited in two lines of discovery. First, BPQ is shown to form a red (BPQ)2Cu(I) complex and promote Ctr1-independent copper-accumulation in whole cells and in mitochondria isolated from treated cells. Multiple phenotypes, including loss of aconitase activity, are consistent with copper-BPQ mediated damage to mitochondrial iron–sulphur clusters. Thus, a biochemical basis of copper-toxicity in S. cerevisiae is analogous to other organisms. Second, iron regulons controlled by Aft1/2, Cth2 and Yap5 that respond to mitochondrial iron–sulphur cluster status are modulated by copper-BPQ causing iron hyper-accumulation via upregulated iron-import. Comparison of copper-BPQ treated, untreated and copper-only treated wild-type and fra2Δ by RNA-seq has uncovered a new candidate Aft1 target-gene (LSO1) and paralogous non-target (LSO2), plus nine putative Cth2 target-transcripts. Two lines of evidence confirm that Fra2 dominates basal repression of the Aft1/2 regulons in iron-replete cultures. Fra2-independent control of these regulons is also observed but CTH2 itself appears to be atypically Fra2-dependent. However, control of Cth2-target transcripts which is independent of CTH2 transcript abundance or of Fra2, is also quantified. Use of copper-BPQ supports a substantial contribution of metabolite repression to iron-regulation. PMID:24895027

Iron, Manganese and Copper Release from Synthetic Hydroxyapatite

NASA Technical Reports Server (NTRS)

Sutter, B.; Hossner, L. R.; Ming, Douglas W.

1999-01-01

Kinetic stir-flow dissolution experiments were performed on iron- (Fe-SHA), manganese- (Mn-SHA), and copper- (Cu-SHA) containing synthetic hydroxyapatites. Solution treatments consisted of de-ionized water, citric acid and DTPA. Initially, Mn concentrations were higher than Cu concentrations and Fe concentrations were the lowest in all treatments. At later times Mn and Cu concentrations dropped in the DTPA treatment while Fe rose to the concentration similar to Mn and Cu. At all times, metal release concentrations in the water and citric acid treatments followed the trend of Mn>Cu>Fe. Rietveld analysis of x-ray diffraction data and ^31P NMR indicated that the metals substituted for Ca in the SHA structure. However, EPR data suggested that a metal (hydr)oxide phase existed either on the SHA surface or between the SHA crystallites. The metal concentration trend of Mn>Cu>Fe suggested that the initial solution metal concentrations are dependent on the dissolution of (hydr)oxides from SHA surfaces or between SHA crystallites. Similar metal concentrations at later times in the DTPA experiments suggests that metal concentrations were controlled by the release of Mn, Cu, or Fe from the SHA structure.

Rapid Size- Controlled Synthesis of Dextran-Coated, Copper-Doped Iron Oxide Nanoparticles

NASA Astrophysics Data System (ADS)

Wong, Ray M.

2011-12-01

Development of dual modality probes enabled for magnetic resonance imaging (MRI) and positron emission tomography (PET) has been on the rise in recent years due to the potential for these probes to facilitate combining the complementary high resolution of MRI and the high sensitivity of PET. The efficient synthesis of multimodal probes that include the radiolabels for PET can be hindered due to prolonged reaction times during radioisotope incorporation, and the resulting decay of the radiolabel. Along with a time-efficient synthesis, one also needs an optimal synthesis that yields products in a desirable size range (between 20-100 nm) to increase blood retention time. In this work, we describe a novel, rapid, microwave-based synthesis of dextran-coated iron oxide nanoparticles doped with copper (DIO/Cu). Traditional methods for synthesizing dextran-coated iron oxide particles require refluxing for 2 hours and result in approximately 50 nm particles. We demonstrate that microwave synthesis can produce 50 nm nanoparticles in 5 minutes of heating. We discuss the various parameters used in the microwave synthesis protocol to vary the size distribution of DIO/Cu, and demonstrate the successful incorporation of copper into these particles with the aim of future use for rapid 64Cu incorporation.

Contact Killing of Bacteria on Copper Is Suppressed if Bacterial-Metal Contact Is Prevented and Is Induced on Iron by Copper Ions

PubMed Central

Mathews, Salima; Hans, Michael

2013-01-01

Bacteria are rapidly killed on copper surfaces, and copper ions released from the surface have been proposed to play a major role in the killing process. However, it has remained unclear whether contact of the bacteria with the copper surface is also an important factor. Using laser interference lithography, we engineered copper surfaces which were covered with a grid of an inert polymer which prevented contact of the bacteria with the surface. Using Enterococcus hirae as a model organism, we showed that the release of ionic copper from these modified surfaces was not significantly reduced. In contrast, killing of bacteria was strongly attenuated. When E. hirae cells were exposed to a solid iron surface, the loss of cell viability was the same as on glass. However, exposing cells to iron in the presence of 4 mM CuSO4 led to complete killing in 100 min. These experiments suggest that contact killing proceeds by a mechanism whereby the metal-bacterial contact damages the cell envelope, which, in turn, makes the cells susceptible to further damage by copper ions. PMID:23396344

The effect of administration of copper nanoparticles to chickens in drinking water on estimated intestinal absorption of iron, zinc, and calcium.

PubMed

Ognik, Katarzyna; Stępniowska, Anna; Cholewińska, Ewelina; Kozłowski, Krzysztof

2016-09-01

Copper nanoparticles used as a dietary supplement for poultry could affect the absorption of mineral elements. Hence the aim of the study was to determine the effect of administration of copper nanoparticles to chickens in drinking water on intestinal absorption of iron, zinc, and calcium. The experiment was carried out on 126 chicks assigned to seven experimental groups of 18 birds each (3 replications of 6 individuals each). The control group (G-C) did not receive copper nanoparticles. Groups: Cu-5(7), Cu-10(7), and Cu-15(7) received gold nanoparticles in their drinking water in the amounts of 5 mg/L for group Cu-5(7), 10 mg/L for group Cu-10(7), and 15 mg/L for group Cu-15(7) during 8 to 14, 22 to 28, and 36 of 42 days of the life of the chicks. The birds in groups Cu-5(3), Cu-10(3), and Cu-15(3) received copper nanoparticles in the same amounts, but only during 8 to 10, 22 to 24, and 36 to 38 days of life. Blood for analysis was collected from the wing vein of all chicks at the age of 42 days. After the rearing period (day 42), six birds from each experimental group with body weight similar to the group average were slaughtered. The carcasses were dissected and samples of the jejunum were collected for analysis of absorption of selected minerals. Mineral absorption was tested using the in vitro gastrointestinal sac technique. Oral administration of copper nanoparticles to chickens in the amount of 5, 10, and 15 mg/L led to accumulation of this element in the intestinal walls. The highest level of copper nanoparticles applied increased Cu content in the blood plasma of the birds. The in vitro study suggests that copper accumulated in the intestines reduces absorption of calcium and zinc, but does not affect iron absorption. © 2016 Poultry Science Association Inc.

Distribution of iron, copper and manganese in the Arabian Sea

NASA Astrophysics Data System (ADS)

Moffett, James

2014-05-01

The distribution of iron, copper and manganese was studied on a zonal transect of the Arabian Sea during the SW monsoon in 2007. The distribution of metals in the eastern and western ends of the transect are completely different, with concentrations of Fe and Mn higher in the east, but copper much higher in the west. Redox cycling in the east, and enhanced ventilation in the west contributes to these processes. It seems likely that blooms of Phaeocystis sp. contribute to the pronounced surface depletion and oxicline regeneration we observe, particularly for copper. The results are very different than similar surveys in the Peru upwelling, indicating controls by very different processes. These results have important implications for carbon and nitrogen cycling, particularly for processes mediated by key Cu and Fe metalloenzymes.

Multi-Copper Oxidases and Human Iron Metabolism

PubMed Central

Vashchenko, Ganna; MacGillivray, Ross T. A.

2013-01-01

Multi-copper oxidases (MCOs) are a small group of enzymes that oxidize their substrate with the concomitant reduction of dioxygen to two water molecules. Generally, multi-copper oxidases are promiscuous with regards to their reducing substrates and are capable of performing various functions in different species. To date, three multi-copper oxidases have been detected in humans—ceruloplasmin, hephaestin and zyklopen. Each of these enzymes has a high specificity towards iron with the resulting ferroxidase activity being associated with ferroportin, the only known iron exporter protein in humans. Ferroportin exports iron as Fe2+, but transferrin, the major iron transporter protein of blood, can bind only Fe3+ effectively. Iron oxidation in enterocytes is mediated mainly by hephaestin thus allowing dietary iron to enter the bloodstream. Zyklopen is involved in iron efflux from placental trophoblasts during iron transfer from mother to fetus. Release of iron from the liver relies on ferroportin and the ferroxidase activity of ceruloplasmin which is found in blood in a soluble form. Ceruloplasmin, hephaestin and zyklopen show distinctive expression patterns and have unique mechanisms for regulating their expression. These features of human multi-copper ferroxidases can serve as a basis for the precise control of iron efflux in different tissues. In this manuscript, we review the biochemical and biological properties of the three human MCOs and discuss their potential roles in human iron homeostasis. PMID:23807651

Analysis of ambient pH stress response mediated by iron and copper intake in Schizosaccharomyces pombe.

PubMed

Higuchi, Yujiro; Mori, Hikari; Kubota, Takeo; Takegawa, Kaoru

2018-01-01

The molecular mechanism of tolerance to alkaline pH is well studied in model fungi Aspergillus nidulans and Saccharomyces cerevisiae. However, how fission yeast Schizosaccharomyces pombe survives under alkaline stress remains largely unknown, as the genes involved in the alkaline stress response pathways of A. nidulans and S. cerevisiae were not found in the genome of this organism. Since uptake of iron and copper into cells is important for alkaline tolerance in S. cerevisiae, here we examined whether iron and copper uptake processes were involved in conferring tolerance to alkaline stress in S. pombe. We first revealed that S. pombe wild-type strain could not grow at a pH higher than 6.7. We further found that the growths of mutants harboring disruption in the iron uptake-related gene frp1 + , fio1 + or fip1 + were severely inhibited under ambient pH stress condition. In contrast, derepression of these genes, by deletion of their repressor gene fep1 + , caused cells to acquire resistance to pH stress. Together, these results suggested that uptake of iron is essential for ambient pH tolerance in S. pombe. We also found that copper is required for the pH stress response because disruptants of ctr4 + , ctr5 + , ccc2 + and cuf1 + genes, all of which are needed for regulating intracellular Cu + , displayed ambient pH sensitivity. Furthermore, supplementing Fe 2+ and Cu 2+ ions to the culture media improved growth under ambient pH stress. Taken together, our results suggested that uptake of iron and copper is the crucial factor needed for the adaptation of S. pombe to ambient pH stress. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Anaerobic Copper Toxicity and Iron-Sulfur Cluster Biogenesis in Escherichia coli.

PubMed

Tan, Guoqiang; Yang, Jing; Li, Tang; Zhao, Jin; Sun, Shujuan; Li, Xiaokang; Lin, Chuxian; Li, Jianghui; Zhou, Huaibin; Lyu, Jianxin; Ding, Huangen

2017-08-15

While copper is an essential trace element in biology, pollution of groundwater from copper has become a threat to all living organisms. Cellular mechanisms underlying copper toxicity, however, are still not fully understood. Previous studies have shown that iron-sulfur proteins are among the primary targets of copper toxicity in Escherichia coli under aerobic conditions. Here, we report that, under anaerobic conditions, iron-sulfur proteins in E. coli cells are even more susceptible to copper in medium. Whereas addition of 0.2 mM copper(II) chloride to LB (Luria-Bertani) medium has very little or no effect on iron-sulfur proteins in wild-type E. coli cells under aerobic conditions, the same copper treatment largely inactivates iron-sulfur proteins by blocking iron-sulfur cluster biogenesis in the cells under anaerobic conditions. Importantly, proteins that do not have iron-sulfur clusters (e.g., fumarase C and cysteine desulfurase) in E. coli cells are not significantly affected by copper treatment under aerobic or anaerobic conditions, indicating that copper may specifically target iron-sulfur proteins in cells. Additional studies revealed that E. coli cells accumulate more intracellular copper under anaerobic conditions than under aerobic conditions and that the elevated copper content binds to the iron-sulfur cluster assembly proteins IscU and IscA, which effectively inhibits iron-sulfur cluster biogenesis. The results suggest that the copper-mediated inhibition of iron-sulfur proteins does not require oxygen and that iron-sulfur cluster biogenesis is the primary target of anaerobic copper toxicity in cells. IMPORTANCE Copper contamination in groundwater has become a threat to all living organisms. However, cellular mechanisms underlying copper toxicity have not been fully understood up to now. The work described here reveals that iron-sulfur proteins in Escherichia coli cells are much more susceptible to copper in medium under anaerobic conditions than they

Anaerobic Copper Toxicity and Iron-Sulfur Cluster Biogenesis in Escherichia coli

PubMed Central

Tan, Guoqiang; Yang, Jing; Li, Tang; Zhao, Jin; Sun, Shujuan; Li, Xiaokang; Lin, Chuxian; Li, Jianghui; Zhou, Huaibin

2017-01-01

ABSTRACT While copper is an essential trace element in biology, pollution of groundwater from copper has become a threat to all living organisms. Cellular mechanisms underlying copper toxicity, however, are still not fully understood. Previous studies have shown that iron-sulfur proteins are among the primary targets of copper toxicity in Escherichia coli under aerobic conditions. Here, we report that, under anaerobic conditions, iron-sulfur proteins in E. coli cells are even more susceptible to copper in medium. Whereas addition of 0.2 mM copper(II) chloride to LB (Luria-Bertani) medium has very little or no effect on iron-sulfur proteins in wild-type E. coli cells under aerobic conditions, the same copper treatment largely inactivates iron-sulfur proteins by blocking iron-sulfur cluster biogenesis in the cells under anaerobic conditions. Importantly, proteins that do not have iron-sulfur clusters (e.g., fumarase C and cysteine desulfurase) in E. coli cells are not significantly affected by copper treatment under aerobic or anaerobic conditions, indicating that copper may specifically target iron-sulfur proteins in cells. Additional studies revealed that E. coli cells accumulate more intracellular copper under anaerobic conditions than under aerobic conditions and that the elevated copper content binds to the iron-sulfur cluster assembly proteins IscU and IscA, which effectively inhibits iron-sulfur cluster biogenesis. The results suggest that the copper-mediated inhibition of iron-sulfur proteins does not require oxygen and that iron-sulfur cluster biogenesis is the primary target of anaerobic copper toxicity in cells. IMPORTANCE Copper contamination in groundwater has become a threat to all living organisms. However, cellular mechanisms underlying copper toxicity have not been fully understood up to now. The work described here reveals that iron-sulfur proteins in Escherichia coli cells are much more susceptible to copper in medium under anaerobic conditions

Interactions of flavonoids with iron and copper ions: a mechanism for their antioxidant activity.

PubMed

Mira, Lurdes; Fernandez, M Tereza; Santos, Marta; Rocha, Rui; Florêncio, M Helena; Jennings, Keith R

2002-11-01

The metal chelating properties of flavonoids suggest that they may play a role in metal-overload diseases and in all oxidative stress conditions involving a transition metal ion. A detailed study has been made of the ability of flavonoids to chelate iron (including Fe3+) and copper ions and its dependence of structure and pH. The acid medium may be important in some pathological conditions. In addition, the ability of flavonoids to reduce iron and copper ions and their activity-structure relationships were also investigated. To fulfill these objectives, flavones (apigenin, luteolin, kaempferol, quercetin, myricetin and rutin), isoflavones (daidzein and genistein), flavanones (taxifolin, naringenin and naringin) and a flavanol (catechin) were investigated. All flavonoids studied show higher reducing capacity for copper ions than for iron ions. The flavonoids with better Fe3+ reducing activity are those with a 2,3-double bond and possessing both the catechol group in the B-ring and the 3-hydroxyl group. The copper reducing activity seems to depend largely on the number of hydroxyl groups. The chelation studies were carried out by means of ultraviolet spectroscopy and electrospray ionisation mass spectrometry. Only flavones and the flavanol catechin interact with metal ions. At pH 7.4 and pH 5.5 all flavones studied appear to chelate Cu2+ at the same site, probably between the 5-hydroxyl and the 4-oxo groups. Myricetin and quercetin, however, at pH 7.4, appear to chelate Cu2+ additionally at the ortho-catechol group, the chelating site for catechin with Cu2+ at pH 7.4. Chelation studies of Fe3+ to flavonoids were investigated only at pH 5.5. Only myricetin and quercetin interact strongly with Fe3+, complexation probably occurring again between the 5-hydroxyl and the 4-oxo groups. Their behaviour can be explained by their ability to reduce Fe3+ at pH 5.5, suggesting that flavonoids reduce Fe3+ to Fe2+ before association.

Effects of rutin supplementation on antioxidant status and iron, copper, and zinc contents in mouse liver and brain.

PubMed

Gao, Zhonghong; Xu, Huibi; Huang, Kaixun

2002-09-01

The effect of rutin on total antioxidant status as well as on trace elements such as iron, copper, and zinc in mouse liver and brain were studied. Mice were administrated with 0.75 g/kg or 2.25 g/kg P. O. of rutin for 30 d consecutively. Following the treatment, the activity of total antioxidant status, catalase, Cu,Zn-superoxide dismutase, Mn-superoxide dismutase, zinc, copper, and iron were measured in mouse liver and brain. The results showed that rutin significantly increased the antioxidant status and Mn-superoxide dismutase activities in mouse liver, but it had no effect on these variables in the brain. Treatment with a higher concentration of rutin significantly decreased catalase activity and iron, zinc, and copper contents in mouse liver; it also resulted in a slower weight gain for the first 20 d. These results indicate that rutin taken in proper amount can effectively improve antioxidant status, whereas at an increased dosage, it may cause trace element (such as iron, zinc, and copper) deficiencies and a decrease in the activities of related metal-containing enzymes.

Cu(II) removal by Anoxybacillus flavithermus-iron oxide composites during the addition of Fe(II)aq

NASA Astrophysics Data System (ADS)

Franzblau, Rachel E.; Daughney, Christopher J.; Swedlund, Peter J.; Weisener, Christopher G.; Moreau, Magali; Johannessen, Bernt; Harmer, Sarah L.

2016-01-01

There is currently poor understanding of metal removal by composites of bacteria and iron oxide minerals, even though they commonly co-occur and are among the most important sorbents in near-surface fluid-rock environments. This study evaluated Cu removal by composites of Anoxybacillus flavithermus and iron oxide over time during the addition, oxidation, and hydrolysis of Fe(II)aq and precipitation of the mineral, in comparison to Cu removal in the two single-sorbent end-member systems. In the absence of iron oxide, Cu removal by A. flavithermus was well described by a previously published surface complexation model, after inclusion of additional reactions describing aqueous complexation by exudate ligands released by the bacteria. In the absence of bacterial cells, Cu removal by iron oxide synthesized in the presence of the bacterial exudate ligands demonstrated the formation of ternary surface complexes. Removal of Cu by the A. flavithermus-iron oxide composites was ca. 20% greater than the prediction based on assumption of additivity in the two end-member systems. This non-additive behavior was attributed to (1) progressive physical blockage of bacterial surface sites by the iron oxide particles, (2) physical blockage of adsorption sites as a result of self-aggregation of the iron oxide particles, and (3) the reduction of Cu(II) to Cu(I) at the bacterial cell surface, as demonstrated by X-ray absorption spectroscopy. The extent of reduction of Cu(II) to Cu(I) was proportional to the concentration of solid phase Fe(II), suggesting that iron oxidation and copper reduction are linked. This study has shown that Cu removal by bacteria-iron oxide composites is greatly affected by redox processes such as Cu(II) reduction on the cell surface both by other bacterial surface ligands and the oxidation of sorbed Fe(II), as well as Fe(II) redox interactions, and aging effects of the mineral (i.e. surface site masking).

Nanoscale zero-valent iron (nZVI) for the treatment of concentrated Cu(II) wastewater: a field demonstration.

PubMed

Li, Shaolin; Wang, Wei; Yan, Weile; Zhang, Wei-xian

2014-03-01

A field demonstration was conducted to assess the feasibility of nanoscale zero-valent iron (nZVI) for the treatment of wastewater containing high levels of Cu(II). Pilot tests were performed at a printed-circuit-board manufacturing plant, treating 250,000 L of wastewater containing 70 mg L(-1) Cu(II) with a total of 55 kg of nZVI. A completely mixed reactor of 1,600 L was operated continuously with flow rates ranging from 1000 to 2500 L h(-1). The average Cu(II) removal efficiency was greater than 96% with 0.20 g L(-1) nZVI and a hydraulic retention time of 100 min. The nZVI reactor achieved a remarkably high volumetric loading rate of 1876 g Cu per m(3) per day for Cu(II) removal, surpassing the loading rates of conventional technologies by more than one order of magnitude. The average removal capacity of nZVI for Cu(II) was 0.343 g Cu per gram of Fe. The Cu(II) removal efficiency can be reliably regulated by the solution Eh, which in turn is a function of nZVI input and hydraulic retention time. The ease of separation and recycling of nZVI contribute to process up-scalability and cost effectiveness. Cu(II) was reduced to metallic copper and cuprite (Cu2O). The end product is a valuable composite of iron and copper (∼20-25%), which can partially offset the treatment costs.

Iodometric determination of peroxydiphosphate in the presence of copper(II) or iron(II) as catalyst.

PubMed

Kapoor, S; Sharma, P D; Gupta, Y K

1975-09-01

Peroxydiphosphate can be determined iodometrically in the presence of a large excess of potassium iodide with copper(II) or iron(II) as catalyst through the operation of the Cu(II)/Cu(I) or Fe(II)/Fe(III) cycle. The method is applicable in HClO(4), H(2)SO(4), HCl and CH(3)COOH acid media in the range 0.1-1.0M studied. Nickel, manganese(II), cobalt(II), silver, chloride and phosphate are without effect.

Determination of copper and iron in biological samples of viral hepatitis (A-E) female patients.

PubMed

Afridi, Hassan Imran; Kazi, Tasneem Gul; Kazi, Naveed Gul; Jamali, Mohammad Khan; Sarfaraz, Raja Adil; Arain, Mohammad Balal; Kandhro, Ghulam Abbas; Shah, Abdul Qadir; Baig, Jamil Ahmed; Jalbani, Nusrat; Ansari, Rehana

2009-01-01

There is accumulative evidence that the metabolism of iron and copper is altered in viral hepatic diseases, and these nutrients might have specific roles in their pathogenesis and progress. The aim of present study was to compare the level of copper (Cu) and iron (Fe) in biological samples (serum, urine, and scalp hair) of female patients suffering from different viral hepatitis (A, B, C, D, and E; n = 253) of age range 31-45 years. For comparative study, 95 healthy females of the same age group residing in the same city were selected. The elements in the biological samples were analyzed by flame atomic absorption spectrophotometry, prior to microwave-assisted acid digestion. The validity and accuracy of the methodology was checked by using certified reference materials (CRMs) and with those values obtained by conventional wet acid digestion method on same CRMs. The results of this study showed that the mean values of Cu and Fe were higher in sera and scalp hair samples of hepatitis patients than age-matched control subjects, while the difference was significant (p < 0.001), in the cases of viral hepatitis B and viral hepatitis C as compared to viral hepatitis A, D, and E. The urinary levels of these elements were found higher in the hepatitis patients than in the age-matched healthy controls (p < 0.05). These results are consistent with literature-reported data, confirming that hepatic iron and copper overload can directly cause lipid peroxidation and eventually hepatic damage.

Synergy of iron and copper oxides in the catalytic formation of PCDD/Fs from 2-monochlorophenol.

PubMed

Potter, Phillip M; Guan, Xia; Lomnicki, Slawomir M

2018-07-01

Transition metal oxides present in waste incineration systems have the ability to catalyze the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) through surface reactions involving organic dioxin precursors. However, studies have concentrated on the catalytic effects of individual transition metal oxides, while the complex elemental composition of fly ash introduces the possibility of synergistic or inhibiting effects between multiple, catalytically active components. In this study, we have tested fly ash surrogates containing different ratios (by weight) of iron (III) oxide and copper (II) oxide. Such Fe 2 O 3 /CuO mixed-oxide surrogates (in the Fe:Cu ratio of 3.5, 0.9 and 0.2 ) were used to study the cooperative effects between two transition metals that are present in high concentrations in most combustion systems and are known to individually catalyze the formation of PCDD/Fs. The presence of both iron and copper oxides increased the oxidative power of the fly ash surrogates in oxygen rich conditions and led to extremely high PCDD/F yields under pyrolytic conditions (up to >5% yield) from 2-monochlorophenol precursor. PCDD/F congener profiles from the mixed oxide samples are similar to results obtained from only CuO, however the total PCDD/F yield increases with increasing Fe 2 O 3 content. Careful analysis of the reaction products and changes to the oxidation states of active metals indicate the CuO surface sites are centers for reaction while the Fe 2 O 3 is affecting the bonds in CuO and increasing the ability of copper centers to form surface-bound radicals that are precursors to PCDD/Fs. Copyright © 2018 Elsevier Ltd. All rights reserved.

Selective nucleation of iron phthalocyanine crystals on micro-structured copper iodide.

PubMed

Rochford, Luke A; Ramadan, Alexandra J; Heutz, Sandrine; Jones, Tim S

2014-12-14

Morphological and structural control of organic semiconductors through structural templating is an efficient route by which to tune their physical properties. The preparation and characterisation of iron phthalocyanine (FePc)-copper iodide (CuI) bilayers at elevated substrate temperatures is presented. Thin CuI(111) layers are prepared which are composed of isolated islands rather than continuous films previously employed in device structures. Nucleation in the early stages of FePc growth is observed at the edges of islands rather than on the top (111) faces with the use of field emission scanning electron microscopy (FE-SEM). Structural measurements show two distinct polymorphs of FePc, with CuI islands edges nucleating high aspect ratio FePc crystallites with modified intermolecular spacing. By combining high substrate temperature growth and micro-structuring of the templating CuI(111) layer structural and morphological control of the organic film is demonstrated.

Impact of substituents and nonplanarity on nickel and copper porphyrin electrochemistry: first observation of a Cu(II)/Cu(III) reaction in nonaqueous media.

PubMed

Fang, Yuanyuan; Senge, Mathias O; Van Caemelbecke, Eric; Smith, Kevin M; Medforth, Craig J; Zhang, Min; Kadish, Karl M

2014-10-06

Electrochemical studies of the oxidation of dodecasubstituted and highly nonplanar nickel porphyrins in a noncoordinating solvent have previously revealed the first nickel(III) porphyrin dication. Herein, we investigate if these nonplanar porphyrins can also be used to detect the so far unobserved copper(III) porphyrin dication. Electrochemical studies of the oxidation of (DPP)Cu and (OETPP)Cu show three processes, the first two of which are macrocycle-centered to give the porphyrin dication followed by a Cu(II)/Cu(III) process at more positive potential. Support for the assignment of the Cu(II)/Cu(III) process comes from the linear relationships observed between E1/2 and the third ionization potential of the central metal ions for iron, cobalt, nickel, and copper complexes of (DPP)M and (OETPP)M. In addition, the oxidation behavior of additional nonplanar nickel porphyrins is investigated in a noncoordinating solvent, with nickel meso-tetraalkylporphyrins also being found to form nickel(III) porphyrin dications. Finally, examination of the nickel meso-tetraalkylporphyrins in a coordinating solvent (pyridine) reveals that the first oxidation becomes metal-centered under these conditions, as was previously noted for a range of nominally planar porphyrins.

Impact of Substituents and Nonplanarity on Nickel and Copper Porphyrin Electrochemistry: First Observation of a CuII/CuIII Reaction in Nonaqueous Media

PubMed Central

2015-01-01

Electrochemical studies of the oxidation of dodecasubstituted and highly nonplanar nickel porphyrins in a noncoordinating solvent have previously revealed the first nickel(III) porphyrin dication. Herein, we investigate if these nonplanar porphyrins can also be used to detect the so far unobserved copper(III) porphyrin dication. Electrochemical studies of the oxidation of (DPP)Cu and (OETPP)Cu show three processes, the first two of which are macrocycle-centered to give the porphyrin dication followed by a CuII/CuIII process at more positive potential. Support for the assignment of the CuII/CuIII process comes from the linear relationships observed between E1/2 and the third ionization potential of the central metal ions for iron, cobalt, nickel, and copper complexes of (DPP)M and (OETPP)M. In addition, the oxidation behavior of additional nonplanar nickel porphyrins is investigated in a noncoordinating solvent, with nickel meso-tetraalkylporphyrins also being found to form nickel(III) porphyrin dications. Finally, examination of the nickel meso-tetraalkylporphyrins in a coordinating solvent (pyridine) reveals that the first oxidation becomes metal-centered under these conditions, as was previously noted for a range of nominally planar porphyrins. PMID:25253031

Iron and copper release in drinking-water distribution systems.

PubMed

Shi, Baoyou; Taylor, James S

2007-09-01

A large-scale pilot study was carried out to evaluate the impacts of changes in water source and treatment process on iron and copper release in water distribution systems. Finished surface waters, groundwaters, and desalinated waters were produced with seven different treatment systems and supplied to 18 pipe distribution systems (PDSs). The major water treatment processes included lime softening, ferric sulfate coagulation, reverse osmosis, nanofiltration, and integrated membrane systems. PDSs were constructed from PVC, lined cast iron, unlined cast iron, and galvanized pipes. Copper pipe loops were set up for corrosion monitoring. Results showed that surface water after ferric sulfate coagulation had low alkalinity and high sulfates, and consequently caused the highest iron release. Finished groundwater treated by conventional method produced the lowest iron release but the highest copper release. The iron release of desalinated water was relatively high because of the water's high chloride level and low alkalinity. Both iron and copper release behaviors were influenced by temperature.

Metallicity of Ca 2Cu 6P 5 with single and double copper-pnictide layers

DOE PAGES

Li, Li; Parker, David; Chi, Miaofang; ...

2016-02-16

We report thermodynamic and transport properties, and also theoretical calculations, for Cu-based compound Ca 2Cu 6P 5 and compare with CaCu 2-δP 2. Both materials have layers of edge-sharing copper pnictide tetrahedral CuP 4, similar to Fe–As and Fe–Se layers (with FeAs 4, FeSe 4) in the iron-based superconductors. Despite the presence of this similar transition-metal pnictide layer, we find that both Ca 2Cu 6P 5 and CaCu 2-δP 2 have temperature-independent magnetic susceptibility and show metallic behavior with no evidence of either magnetic ordering or superconductivity down to 1.8 K CaCu 2-δP 2 is slightly off-stoichiometric, with δ =more » 0.14. Theoretical calculations suggest that unlike Fe 3d-based magnetic materials with a large density of states (DOS) at the Fermi surface, Cu have comparatively low DOS, with the majority of the 3d spectral weight located well below Fermi level. The room-temperature resistivity value of Ca 2Cu 6P 5 is only 9 μΩ-cm, due to a substantial plasma frequency and an inferred electron-phonon coupling λ of 0.073 (significantly smaller than that of metallic Cu). Also, microscopy result shows that Cu–Cu distance along the c-axis within the double layers can be very short (2.5 Å), even shorter than metallic elemental copper bond (2.56 Å). The value of dρ/dT for CaCu 2-δP 2 at 300 K is approximately three times larger than in Ca 2Cu 6P 5, which suggests the likelihood of stronger electron-phonon coupling. Lastly, this study shows that the details of Cu–P layers and bonding are important for their transport characteristics. In addition, it emphasizes the remarkable character of the DOS of ‘122’ iron-based materials, despite much structural similarities.« less

Copper, iron and zinc absorption, retention and status of young women fed vitamin B-6 deficient diets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turnlund, J.R.; Keyes, W.R.; Hudson, C.A.

1991-03-11

A study was conducted in young women to determine the effect of vitamin B-6 deficient diets on copper, iron and zinc metabolism. Young women were confined to a metabolic research unit for 84 and 98 days. They were fed a vitamin B-6 deficient formula diet initially, followed by food diet containing four increasing levels of vitamin B-6. Copper, iron and zinc absorption, retention and status were determined at intervals throughout the study. Absorption was determined using the stable isotopes {sup 65}Cu, {sup 54}Fe, and {sup 67}Zn. Status was based on serum copper and zinc, hemoglobin, hematocrit and mean corpuscular volume.more » Copper absorption averaged 18 {plus minus} 1% during vitamin B-6 depletion, significantly lower than 24 {plus minus} 1% during repletion, but serum copper was not affected and balance was positive. Iron absorption was not impaired significantly by vitamin B-6 deficient diets, but status declined during the depletion period. Zinc absorption averaged 40 {plus minus} 2% during depletion and 27 {plus minus} 2% during repletion. Zinc absorption and retention were significantly greater during vitamin B-6 depletion, but serum zinc declined suggesting the absorbed zinc was not available for utilization. The results suggest that vitamin B-6 depletion of young women may inhibit copper absorption, affect iron status and alter zinc metabolism. The effects of vitamin B-6 depletion differ markedly among these elements.« less

Negative permittivity and permeability spectra of Cu/yttrium iron garnet hybrid granular composite materials in the microwave frequency range

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsutaoka, Takanori, E-mail: tsutaok@hiroshima-u.ac.jp; Fukuyama, Koki; Kinoshita, Hideaki

2013-12-23

The relative complex permittivity and permeability spectra of the coagulated copper and yttrium iron garnet (Cu/YIG) hybrid granular composite materials have been studied in the microwave range. The insulator to metal transition was observed at the percolation threshold of Cu particle content (φ{sub Cu} = 16.0 vol. %) in the electrical conductivity. In the percolation threshold, the low frequency plasmonic state caused by the metallic Cu particle networks was observed. The percolated Cu/YIG granular composites show simultaneous negative permittivity and permeability spectra under external magnetic fields.

Cosmogenic effects on Cu isotopes in IVB iron meteorites

NASA Astrophysics Data System (ADS)

Chen, Heng; Moynier, Frédéric; Humayun, Munir; Bishop, M. Cole; Williams, Jeffrey T.

2016-06-01

We measured Cu isotope compositions of 12 out of the 14 known IVB iron meteorites. Our results show that IVB iron meteorites display a very large range of δ65Cu values (-5.84‰ < δ65Cu < -0.24‰; defined as per mil deviation of the 65Cu/63Cu ratio from the NIST-976 standard). These Cu isotopic data display clear correlations with W, Pt, and Os isotope ratios, which are very sensitive to secondary neutron capture due to galactic cosmic ray (GCR) irradiation. This demonstrates that δ65Cu in IVB irons is majorly modified by neutron capture by the reaction 62Ni(n,γ)63Ni followed by beta decay to 63Cu. Using correlations with Pt and Os neutron dosimeters, we calculated a pre-exposure δ65Cu of -0.3 ± 0.8‰ (95% conf.) of IVB irons that agrees well with the Cu isotopic compositions of other iron meteorite groups and falls within the range of chondrites. This shows that the volatile depletion of the IVB parent body is not due to evaporation that should have enriched IVB irons in the heavy Cu isotopes.

Copper interstitial recombination centers in Cu 3 N

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yee, Ye Sheng; Inoue, Hisashi; Hultqvist, Adam

We present a comprehensive study of the earth-abundant semiconductor Cu 3N as a potential solar energy conversion material, using density functional theory and experimental methods. Density functional theory indicates that among the dominant intrinsic point defects, copper vacancies V Cu have shallow defect levels while copper interstitials Cu i behave as deep potential wells in the conduction band which mediate Shockley-Read-Hall recombination. The existence of Cu i defects has been experimentally verified using photothermal deflection spectroscopy. A Cu 3N/ZnS heterojunction diode with good current-voltage rectification behavior has been demonstrated experimentally, but no photocurrent is generated under illumination. Finally, the absencemore » of photocurrent can be explained by a large concentration of Cu i recombination centers capturing electrons in p-type Cu 3N.« less

Copper interstitial recombination centers in Cu 3 N

DOE PAGES

Yee, Ye Sheng; Inoue, Hisashi; Hultqvist, Adam; ...

2018-06-04

We present a comprehensive study of the earth-abundant semiconductor Cu 3N as a potential solar energy conversion material, using density functional theory and experimental methods. Density functional theory indicates that among the dominant intrinsic point defects, copper vacancies V Cu have shallow defect levels while copper interstitials Cu i behave as deep potential wells in the conduction band which mediate Shockley-Read-Hall recombination. The existence of Cu i defects has been experimentally verified using photothermal deflection spectroscopy. A Cu 3N/ZnS heterojunction diode with good current-voltage rectification behavior has been demonstrated experimentally, but no photocurrent is generated under illumination. Finally, the absencemore » of photocurrent can be explained by a large concentration of Cu i recombination centers capturing electrons in p-type Cu 3N.« less

Copper and Copper Proteins in Parkinson's Disease

PubMed Central

Rivera-Mancia, Susana; Diaz-Ruiz, Araceli; Tristan-Lopez, Luis; Rios, Camilo

2014-01-01

Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson's disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson's disease patients. Copper influences iron content in the brain through ferroxidase ceruloplasmin activity; therefore decreased protein-bound copper in brain may enhance iron accumulation and the associated oxidative stress. The function of other copper-binding proteins such as Cu/Zn-SOD and metallothioneins is also beneficial to prevent neurodegeneration. Copper may regulate neurotransmission since it is released after neuronal stimulus and the metal is able to modulate the function of NMDA and GABA A receptors. Some of the proteins involved in copper transport are the transporters CTR1, ATP7A, and ATP7B and the chaperone ATOX1. There is limited information about the role of those biomolecules in the pathophysiology of Parkinson's disease; for instance, it is known that CTR1 is decreased in substantia nigra pars compacta in Parkinson's disease and that a mutation in ATP7B could be associated with Parkinson's disease. Regarding copper-related therapies, copper supplementation can represent a plausible alternative, while copper chelation may even aggravate the pathology. PMID:24672633

Iron, copper, and zinc status: response to supplementation with zinc or zinc and iron in adult females.

PubMed

Yadrick, M K; Kenney, M A; Winterfeldt, E A

1989-01-01

Response of iron, copper, and zinc status to supplementation with Zn or a combination of Zn and Fe was assessed in adult females in a 10-wk study. Group Z received 50 mg Zn/d as Zn gluconate; group F-Z received 50 mg Fe as ferrous sulfate monohydrate in addition to the Zn. For Group Z, serum ferritin, hematocrit, and erythrocyte Cu,Zn-superoxide dismutase (ESOD) were significantly lower (p less than 0.05) after 10 wk supplementation compared with pretreatment levels. Serum Zn increased (p less than 0.01) but no change occurred in serum ceruloplasmin, hemoglobin, or salivary sediment Zn with treatment. For Group F-Z ESOD decreased with treatment as did salivary sediment Zn (p less than 0.05). Serum ferritin and serum Zn increased significantly, but hemoglobin, hematocrit, and ceruloplasmin were not affected by this treatment. Supplementation with Zn poses a risk to Fe and Cu status. Inclusion of Fe with Zn ameliorates the effect on Fe but not on Cu status.

Redox chemistry of a binary transition metal oxide (AB2O4): a study of the Cu(2+)/Cu(0) and Fe(3+)/Fe(0) interconversions observed upon lithiation in a CuFe2O4 battery using X-ray absorption spectroscopy.

PubMed

Cama, Christina A; Pelliccione, Christopher J; Brady, Alexander B; Li, Jing; Stach, Eric A; Wang, Jiajun; Wang, Jun; Takeuchi, Esther S; Takeuchi, Kenneth J; Marschilok, Amy C

2016-06-22

Copper ferrite, CuFe2O4, is a promising candidate for application as a high energy electrode material in lithium based batteries. Mechanistic insight on the electrochemical reduction and oxidation processes was gained through the first X-ray absorption spectroscopic study of lithiation and delithiation of CuFe2O4. A phase pure tetragonal CuFe2O4 material was prepared and characterized using laboratory and synchrotron X-ray diffraction, Raman spectroscopy, and transmission electron microscopy. Ex situ X-ray absorption spectroscopy (XAS) measurements were used to study the battery redox processes at the Fe and Cu K-edges, using X-ray absorption near-edge structure (XANES), extended X-ray absorption fine structure (EXAFS), and transmission X-ray microscopy (TXM) spectroscopies. EXAFS analysis showed upon discharge, an initial conversion of 50% of the copper(ii) to copper metal positioned outside of the spinel structure, followed by a migration of tetrahedral iron(iii) cations to octahedral positions previously occupied by copper(ii). Upon charging to 3.5 V, the copper metal remained in the metallic state, while iron metal oxidation to iron(iii) was achieved. The results provide new mechanistic insight regarding the evolution of the local coordination environments at the iron and copper centers upon discharging and charging.

A porous Cu/LDPE composite for copper-containing intrauterine contraceptive devices.

PubMed

Zhang, Weiwei; Xia, Xianping; Qi, Cheng; Xie, Changsheng; Cai, Shuizhou

2012-02-01

To improve the rates of both cupric ion release and the utilization of copper in non-porous copper/low-density polyethylene (Cu/LDPE) composite, a porous Cu/LDPE composite is proposed and developed in the present work. Here 2,5-di-tert-butylhydroquinone was chosen as the porogen, ethyl acetate was chosen as the solvent for extraction, and the porous Cu/LDPE composite was obtained by using injection molding and the particulate leaching method. After any residual ethyl acetate remaining inside the porous Cu/LDPE composite had been removed by vacuum drying, the composite was characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, gas chromatography-mass spectrometry and absorption measurement. For comparison, a non-porous Cu/LDPE composite was also characterized in the same way. The results show that the porous structure was successfully introduced into the polymeric base of the non-porous Cu/LDPE composite, and the porous Cu/LDPE composite is a simple hybrid of copper particles and porous LDPE. The results also show that the introduction of a porous structure can improve the cupric ion release rate of the non-porous Cu/LDPE composite with a certain content of copper particles, indicating that the utilization rate of copper can be improved either the introduction of a porous structure, and that the porous Cu/LDPE composite is another promising material for copper-containing intrauterine devices. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Microstructure and properties of pure iron/copper composite cladding layers on carbon steel

NASA Astrophysics Data System (ADS)

Wan, Long; Huang, Yong-xian; Lü, Shi-xiong; Huang, Ti-fang; Lü, Zong-liang

2016-08-01

In the present study, pure iron/copper composite metal cladding was deposited onto carbon steel by tungsten inert gas welding. The study focused on interfacial morphological, microstructural, and mechanical analyses of the composite cladding layers. Iron liquid-solid-phase zones were formed at copper/steel and iron interfaces because of the melting of the steel substrate and iron. Iron concentrated in the copper cladding layer was observed to exhibit belt, globule, and dendrite morphologies. The appearance of iron-rich globules indicated the occurrence of liquid phase separation (LPS) prior to solidification, and iron-rich dendrites crystallized without the occurrence of LPS. The maximum microhardness of the iron/steel interface was lower than that of the copper/steel interface because of the diffusion of elemental carbon. All samples fractured in the cladding layers. Because of a relatively lower strength of the copper layer, a short plateau region appeared when shear movement was from copper to iron.

Effect of oxygen, methyl mercaptan, and methyl chloride on friction behavior of copper-iron contacts

NASA Technical Reports Server (NTRS)

Buckley, D. H.

1978-01-01

Sliding friction experiments were conducted with an iron rider on a copper disk and a copper rider on an iron disk. The sputter cleaned iron and copper disk surfaces were saturated with oxygen, methyl mercaptan, and methyl chloride at atmospheric pressure. Auger emission spectroscopy was used to monitor the surfaces. Lower friction was obtained in all experiments with the copper rider sliding on the iron disk than when the couple was reversed. For both iron and copper disks, methyl mercaptan gave the best surface coverage and was most effective in reducing friction. For both iron and copper disks, methyl chloride was the least effective in reducing friction. With sliding, copper transferred to iron and iron to copper.

Impaired copper and iron metabolism in blood cells and muscles of patients affected by copper deficiency myeloneuropathy.

PubMed

Spinazzi, Marco; Sghirlanzoni, Angelo; Salviati, Leonardo; Angelini, Corrado

2014-12-01

Severe copper deficiency leads in humans to a treatable multisystem disease characterized by anaemia and degeneration of spinal cord and nerves, but its mechanisms have not been investigated. We tested whether copper deficit leads to alterations in fundamental copper-dependent proteins and in iron metabolism in blood and muscles of patients affected by copper deficiency myeloneuropathy, and if these metabolic abnormalities are associated with compensatory mechanisms for copper maintenance. We evaluated the expression of critical copper enzymes, of iron-related proteins, and copper chaperones and transporters in blood and muscles from five copper-deficient patients presenting with subacute sensory ataxia, muscle paralysis, liver steatosis and variable anaemia. Severe copper deficiency was caused by chronic zinc intoxication in all of the patients, with an additional history of gastrectomy in two cases. The antioxidant enzyme SOD1 and subunit 2 of cytochrome c oxidase were significantly decreased in blood cells and in muscles of copper-deficient patients compared with controls. In muscle, the iron storage protein ferritin was dramatically reduced despite normal serum ferritin, and the expression of the haem-proteins cytochrome c and myoglobin was impaired. Muscle expression of the copper transporter CTR1 and of the copper chaperone CCS, was strikingly increased, while antioxidant protein 1 was diminished. copper-dependent enzymes with critical functions in antioxidant defences, in mitochondrial energy production, and in iron metabolism are affected in blood and muscles of patients with profound copper deficiency leading to myeloneuropathy. Homeostatic mechanisms are strongly activated to increase intracellular copper retention. © 2013 British Neuropathological Society.

Iron and copper as virulence modulators in human fungal pathogens.

PubMed

Ding, Chen; Festa, Richard A; Sun, Tian-Shu; Wang, Zhan-You

2014-07-01

Fungal pathogens have evolved sophisticated machinery to precisely balance the fine line between acquiring essential metals and defending against metal toxicity. Iron and copper are essential metals for many processes in both fungal pathogens and their mammalian hosts, but reduce viability when present in excess. However, during infection, the host uses these two metals differently. Fe has a long-standing history of influencing virulence in pathogenic fungi, mostly in regards to Fe acquisition. Numerous studies demonstrate the requirement of the Fe acquisition pathway of Candida, Cryptococcus and Aspergillus for successful systemic infection. Fe is not free in the host, but is associated with Fe-binding proteins, leading fungi to develop mechanisms to interact with and to acquire Fe from these Fe-bound proteins. Cu is also essential for cell growth and development. Essential Cu-binding proteins include Fe transporters, superoxide dismutase (SOD) and cytochrome c oxidase. Although Cu acquisition plays critical roles in fungal survival in the host, recent work has revealed that Cu detoxification is extremely important. Here, we review fungal responses to altered metal conditions presented by the host, contrast the roles of Fe and Cu during infection, and outline the critical roles of fungal metal homeostasis machinery at the host-pathogen axis. © 2014 John Wiley & Sons Ltd.

Evaluation of Fe-containing Li2CuO2 on CO2 capture performed at different physicochemical conditions.

PubMed

Yañez-Aulestia, Ana; Ovalle-Encinia, Oscar; Pfeiffer, Heriberto

2018-06-05

Li 2 CuO 2 and different iron-containing Li 2 CuO 2 samples were synthesized by solid state reaction. On iron-containing samples, atomic sites of copper are substituted by iron ions in the lattice (XRD and Rietveld analyses). Iron addition induces copper release from Li 2 CuO 2 , which produce cationic vacancies and CuO, due to copper (Cu 2+ ) and iron (Fe 3+ ) valence differences. Two different physicochemical conditions were used for analyzing CO 2 capture on these samples; (i) high temperature and (ii) low temperature in presence of water vapor. At high temperatures, iron addition increased CO 2 chemisorption, due to structural and chemical variations on Li 2 CuO 2 . Kinetic analysis performed by first order reaction and Eyring models evidenced that iron addition on Li 2 CuO 2 induced a faster CO 2 chemisorption but a higher thermal dependence. Conversely, CO 2 chemisorption at low temperature in water vapor presence practically did not vary by iron addition, although hydration and hydroxylation processes were enhanced. Moreover, under these physicochemical conditions the whole sorption process became slower on iron-containing samples, due to metal oxides presence.

Formation of Copper Sulfide Precipitate in Solid Iron

NASA Astrophysics Data System (ADS)

Urata, Kentaro; Kobayashi, Yoshinao

The growth rate of copper sulfide precipitates has been measured in low carbon steel samples such as Fe-0.3mass%Cu-0.03mass%S-0.1mass%C and Fe-0.1mass%Cu-0.01mass%S- 0.1mass%C. Heat-treatment of the samples was conducted at 1273, 1423 and 1573 K for 100 s - 14.4 ks for precipitation of copper sulfides and then the samples were observed by a scanning electron microscope and a transmission electron microscope to measure the diameter of copper sulfides precipitated in the samples. The growth rate of copper sulfide has been found to be well described by the Ostwald growth model, as follows: R\

High-Iron Consumption Impairs Growth and Causes Copper-Deficiency Anemia in Weanling Sprague-Dawley Rats

PubMed Central

Ha, Jung-Heun; Doguer, Caglar; Wang, Xiaoyu; Flores, Shireen R.; Collins, James F.

2016-01-01

Iron-copper interactions were described decades ago; however, molecular mechanisms linking the two essential minerals remain largely undefined. Investigations in humans and other mammals noted that copper levels increase in the intestinal mucosa, liver and blood during iron deficiency, tissues all important for iron homeostasis. The current study was undertaken to test the hypothesis that dietary copper influences iron homeostasis during iron deficiency and iron overload. We thus fed weanling, male Sprague-Dawley rats (n = 6-11/group) AIN-93G-based diets containing high (~8800 ppm), adequate (~80) or low (~11) iron in combination with high (~183), adequate (~8) or low (~0.9) copper for 5 weeks. Subsequently, the iron- and copper-related phenotype of the rats was assessed. Rats fed the low-iron diets grew slower than controls, with changes in dietary copper not further influencing growth. Unexpectedly, however, high-iron (HFe) feeding also impaired growth. Furthermore, consumption of the HFe diet caused cardiac hypertrophy, anemia, low serum and tissue copper levels and decreased circulating ceruloplasmin activity. Intriguingly, these physiologic perturbations were prevented by adding extra copper to the HFe diet. Furthermore, higher copper levels in the HFe diet increased serum nonheme iron concentration and transferrin saturation, exacerbated hepatic nonheme iron loading and attenuated splenic nonheme iron accumulation. Moreover, serum erythropoietin levels, and splenic erythroferrone and hepatic hepcidin mRNA levels were altered by the dietary treatments in unanticipated ways, providing insight into how iron and copper influence expression of these hormones. We conclude that high-iron feeding of weanling rats causes systemic copper deficiency, and further, that copper influences the iron-overload phenotype. PMID:27537180

Copper(I)- and copper(0)-promoted homocoupling and homocoupling-hydrodehalogenation reactions of dihalogenoclathrochelate precursors for C-C conjugated iron(II) bis-cage complexes.

PubMed

Varzatskii, Oleg A; Shul'ga, Sergey V; Belov, Alexander S; Novikov, Valentin V; Dolganov, Alexander V; Vologzhanina, Anna V; Voloshin, Yan Z

2014-12-28

Iron(II) dibromo- and diiodoclathrochelates undergo copper(I)-promoted reductive homocoupling in HMPA at 70-80 °C leading to C-C conjugated dibromo- and diiodo-bis-clathrochelates in high yields. Under the same conditions, their dichloroclathrochelate analog does not undergo the same homocoupling reaction, so the target dichloro-bis-cage product was obtained in high yield via dimerization of its heterodihalogenide iodochloromonomacrobicyclic precursor. The use of NMP as a solvent at 120-140 °C gave the mixture of bis-clathrochelates resulting from a tandem homocoupling-hydrodehalogenation reaction: the initial acetonitrile copper(I) solvato-complex at a high temperature underwent re-solvatation and disproportionation leading to Cu(II) ions and nano-copper, which promoted the hydrodehalogenation process even at room temperature. The most probable pathway of this reaction in situ includes hydrodehalogenation of the already formed dihalogeno-bis-clathrochelate via the formation of reduced anion radical intermediates. As a result, chemical transformations of the iron(II) dihalogenoclathrochelates in the presence of an acetonitrile copper(I) solvato-complex were found to depend both on the nature of halogen atoms in their ribbed chelate fragments and on reaction conditions (i.e. solvent and temperature). The C-C conjugated iron(II) dihalogeno-bis-clathrochelates easily undergo nucleophilic substitution with various N,S-nucleophiles giving ribbed-functionalized bis-cage species. These iron(II) complexes were characterized by elemental analysis, MALDI-TOF mass spectrometry, IR, UV-Vis, (1)H and (13)C NMR spectroscopy, and by X-ray diffraction; their electrochemical properties were studied by cyclic voltammetry. The isomeric shift values in (57)Fe Mössbauer spectra of such cage compounds allowed identifying them as low-spin iron(II) complexes, while those of the quadrupole splitting are the evidence for a significant TP distortion of their FeN6-coordination polyhedra

Redox chemistry of a binary transition metal oxide (AB 2 O 4 ): a study of the Cu 2+ /Cu 0 and Fe 3+ /Fe 0 interconversions observed upon lithiation in a CuFe 2 O 4 battery using X-ray absorption spectroscopy

DOE PAGES

Cama, Christina A.; Pelliccione, Christopher J.; Brady, Alexander B.; ...

2016-06-06

Copper ferrite, CuFe 2 O 4, is a promising candidate for application as a high energy electrode material in lithium based batteries. Mechanistic insight on the electrochemical reduction and oxidation processes was gained through the first X-ray absorption spectroscopic study of lithiation and delithiation of CuFe 2 O 4. A phase pure tetragonal CuFe 2 O 4 material was prepared and characterized using laboratory and synchrotron X-ray diffraction, Raman spectroscopy, and transmission electron microscopy. We used ex situ X-ray absorption spectroscopy (XAS) measurements to study the battery redox processes at the Fe and Cu K-edges, using X-ray absorption near-edge structuremore » (XANES), extended X-ray absorption fine structure (EXAFS), and transmission X-ray microscopy (TXM) spectroscopies. EXAFS analysis showed upon discharge, an initial conversion of 50% of the copper(II) to copper metal positioned outside of the spinel structure, followed by a migration of tetrahedral iron(III) cations to octahedral positions previously occupied by copper(II). Then, upon charging to 3.5 V, the copper metal remained in the metallic state, while iron metal oxidation to iron(III) was achieved. Our results provide new mechanistic insight regarding the evolution of the local coordination environments at the iron and copper centers upon discharging and charging.« less

Pathogenic adaptations to host-derived antibacterial copper

PubMed Central

Chaturvedi, Kaveri S.; Henderson, Jeffrey P.

2014-01-01

Recent findings suggest that both host and pathogen manipulate copper content in infected host niches during infections. In this review, we summarize recent developments that implicate copper resistance as an important determinant of bacterial fitness at the host-pathogen interface. An essential mammalian nutrient, copper cycles between copper (I) (Cu+) in its reduced form and copper (II) (Cu2+) in its oxidized form under physiologic conditions. Cu+ is significantly more bactericidal than Cu2+ due to its ability to freely penetrate bacterial membranes and inactivate intracellular iron-sulfur clusters. Copper ions can also catalyze reactive oxygen species (ROS) generation, which may further contribute to their toxicity. Transporters, chaperones, redox proteins, receptors and transcription factors and even siderophores affect copper accumulation and distribution in both pathogenic microbes and their human hosts. This review will briefly cover evidence for copper as a mammalian antibacterial effector, the possible reasons for this toxicity, and pathogenic resistance mechanisms directed against it. PMID:24551598

Smelting reduction and kinetics analysis of magnetic iron in copper slag using waste cooking oil.

PubMed

Li, Bo; Wang, Xubin; Wang, Hua; Wei, Yonggang; Hu, Jianhang

2017-05-25

To improve the recovery of copper, the viscosity of copper molten slag is decreased by the reduction of magnetic iron, which, in turn, accelerates the settling and separation of copper droplets from the slag. A new technology is proposed in which waste cooking oil is used as a reductant to reduce magnetic iron in the copper smelting slag and consequently reduce carbon emissions in the copper smelting process. A kinetic model of the reduction of magnetic iron in copper slag by waste cooking oil was built using experimental data, and the accuracy of the model was verified. The results indicated that the magnetic iron content in the copper slag decreased with increasing reduction time and an increase in temperature more efficiently reduced magnetic iron in the copper slag. The magnetic iron in the copper slag gradually transformed to fayalite, and the viscosity of the copper molten slag decreased as the magnetic iron content decreased during the reduction process. The reduction of magnetic iron in the copper molten slag using waste cooking oil was a first-order reaction, and the rate-limiting step was the mass transfer of Fe 3 O 4 through the liquid boundary layer.

Ionic configuration of copper ferrimanganites Cu 0.5Mn xFe 2.5- xO 4

NASA Astrophysics Data System (ADS)

Lenglet, M.; Kasperek, J.; Hannoyer, B.; Lopitaux, J.; d'Huysser, A.; Tellier, J. C.

1992-06-01

Mössbauer spectrometry, neutron diffraction, XANES, and XPS have led to the determination of the cation distributions of the system Cu 0.5Mn xFe 2.5- xO 4 (0≤ x≤1.5). The three cations are present in both tetrahedral and octahedral sites, and the relative number of Fe ions on A- and B-sites remains nearly constant in the whole range of x. It appears that for x≤0.5 manganese is divalent and copper is in its two oxidation states. For x>0.5 copper and iron are respectively divalent and trivalent; the manganese is in +2 and +3 oxydation states.

Levels of plasma ceruloplasmin protein are markedly lower following dietary copper deficiency in rodents

PubMed Central

Broderius, Margaret; Mostad, Elise; Wendroth, Krista; Prohaska, Joseph R.

2010-01-01

Ceruloplasmin (Cp) is a multicopper oxidase and the most abundant copper binding protein in vertebrate plasma. Loss of function mutations in humans or experimental deletion in mice result in iron overload consistent with a putative ferroxidase function. Prior work suggested plasma may contain multiple ferroxidases. Studies were conducted in Holtzman rats (Rattus novegicus), albino mice (Mus musculus), Cp -/- mice, and adult humans (Homo sapiens) to investigate the copper-iron interaction. Dietary copper-deficient (CuD) rats and mice were produced using a modified AIN-76A diet. Results confirmed that o-dianisidine is a better substrate than paraphenylene diamine (PPD) for assessing diamine oxidase activity of Cp. Plasma from CuD rat dams and pups, and CuD and Cp -/- mice contained no detectable Cp diamine oxidase activity. Importantly, no ferroxidase activity was detectable for CuD rats, mice, or Cp -/- mice compared to robust activity for copper-adequate (CuA) rodent controls using western membrane assay. Immunoblot protocols detected major reductions (60-90%) in Cp protein in plasma of CuD rodents but no alteration in liver mRNA levels by qRT-PCR. Data are consistent with apo-Cp being less stable than holo-Cp. Further research is needed to explain normal plasma iron in CuD mice. Reduction in Cp is a sensitive biomarker for copper deficiency. PMID:20170749

Iron versus Copper II. Principles and Applications in Bioinorganic Chemistry.

ERIC Educational Resources Information Center

Ochiai, Ei-Ichiro

1986-01-01

Discusses the differences between iron and copper. Describes various aspects of the behaviors of these two elements, including those of biological and environmental significance. Addresses the evolution of the atmosphere and sedimentary ore formation, the phylogeny of iron and copper, and some anthropological notes regarding the use of the metals.…

Copper interstitial recombination centers in Cu3N

NASA Astrophysics Data System (ADS)

Yee, Ye Sheng; Inoue, Hisashi; Hultqvist, Adam; Hanifi, David; Salleo, Alberto; Magyari-Köpe, Blanka; Nishi, Yoshio; Bent, Stacey F.; Clemens, Bruce M.

2018-06-01

We present a comprehensive study of the earth-abundant semiconductor Cu3N as a potential solar energy conversion material, using density functional theory and experimental methods. Density functional theory indicates that among the dominant intrinsic point defects, copper vacancies VCu have shallow defect levels while copper interstitials Cui behave as deep potential wells in the conduction band, which mediate Shockley-Read-Hall recombination. The existence of Cui defects has been experimentally verified using photothermal deflection spectroscopy. A Cu3N /ZnS heterojunction diode with good current-voltage rectification behavior has been demonstrated experimentally, but no photocurrent is generated under illumination. The absence of photocurrent can be explained by a large concentration of Cui recombination centers capturing electrons in p -type Cu3N .

Overlap of copper and iron uptake systems in mitochondria in Saccharomyces cerevisiae

PubMed Central

Wang, Jing; Gammon, Micah G.; Maynard, Margaret K.; White, Olivia L.; Cobine, Jai A.; Mahone, Wilkerson K.

2016-01-01

In Saccharomyces cerevisiae, the mitochondrial carrier family protein Pic2 imports copper into the matrix. Deletion of PIC2 causes defects in mitochondrial copper uptake and copper-dependent growth phenotypes owing to decreased cytochrome c oxidase activity. However, copper import is not completely eliminated in this mutant, so alternative transport systems must exist. Deletion of MRS3, a component of the iron import machinery, also causes a copper-dependent growth defect on non-fermentable carbon. Deletion of both PIC2 and MRS3 led to a more severe respiratory growth defect than either individual mutant. In addition, MRS3 expressed from a high copy number vector was able to suppress the oxygen consumption and copper uptake defects of a strain lacking PIC2. When expressed in Lactococcus lactis, Mrs3 mediated copper and iron import. Finally, a PIC2 and MRS3 double mutant prevented the copper-dependent activation of a heterologously expressed copper sensor in the mitochondrial intermembrane space. Taken together, these data support a role for the iron transporter Mrs3 in copper import into the mitochondrial matrix. PMID:26763345

Copper increases reductive dehalogenation of haloacetamides by zero-valent iron in drinking water: Reduction efficiency and integrated toxicity risk.

PubMed

Chu, Wenhai; Li, Xin; Bond, Tom; Gao, Naiyun; Bin, Xu; Wang, Qiongfang; Ding, Shunke

2016-12-15

The haloacetamides (HAcAms), an emerging class of nitrogen-containing disinfection byproducts (N-DBPs), are highly cytotoxic and genotoxic, and typically occur in treated drinking waters at low μg/L concentrations. Since many drinking distribution and storage systems contain unlined cast iron and copper pipes, reactions of HAcAms with zero-valent iron (ZVI) and metallic copper (Cu) may play a role in determining their fate. Moreover, ZVI and/or Cu are potentially effective HAcAm treatment technologies in drinking water supply and storage systems. This study reports that ZVI alone reduces trichloroacetamide (TCAcAm) to sequentially form dichloroacetamide (DCAcAm) and then monochloroacetamide (MCAcAm), whereas Cu alone does not impact HAcAm concentrations. The addition of Cu to ZVI significantly improved the removal of HAcAms, relative to ZVI alone. TCAcAm and their reduction products (DCAcAm and MCAcAm) were all decreased to below detection limits at a molar ratio of ZVI/Cu of 1:1 after 24 h reaction (ZVI/TCAcAm = 0.18 M/5.30 μM). TCAcAm reduction increased with the decreasing pH from 8.0 to 5.0, but values from an integrated toxic risk assessment were minimised at pH 7.0, due to limited removal MCAcAm under weak acid conditions (pH = 5.0 and 6.0). Higher temperatures (40 °C) promoted the reductive dehalogenation of HAcAms. Bromine was preferentially removed over chlorine, thus brominated HAcAms were more easily reduced than chlorinated HAcAms by ZVI/Cu. Although tribromoacetamide was more easily reduced than TCAcAm during ZVI/Cu reduction, treatment of tribromoacetamide resulted in a higher integrated toxicity risk than TCAcAm, due to the formation of monobromoacetamide (MBAcAm). Copyright © 2016 Elsevier Ltd. All rights reserved.

Variation of calcium, copper and iron levels in serum, bile and stone samples of patients having different types of gallstone: A comparative study.

PubMed

Khan, Mustafa; Kazi, Tasneem Gul; Afridi, Hassan Imran; Sirajuddin; Bilal, Muhammad; Akhtar, Asma; Khan, Sabir; Kadar, Salma

2017-08-01

Epidemiological data among the human population has shown a significantly increased incidence of gallstone (GS) disease worldwide. It was studied that some essential (calcium) and transition elements (iron and copper) in bile play an important role in the development of GS. The estimation of calcium, copper and iron were carried out in the serum, gall bladder bile and different types of GS (cholesterol, mixed and pigmented) of 172 patients, age ranged 20-55years. For comparative purpose age matched referents not suffering from GS diseases were also selected. Biliary concentrations of calcium (Ca), iron (Fe) and copper (Cu) were correlated with their concentrations in serum and different types of GS samples. The ratio of Ca, Fe and Cu in bile with serum was also calculated. Understudy metals were determined by flame atomic absorption spectroscopy after acid decomposition of matrices of selected samples. The Ca concentrations in serum samples were significantly higher in patients with pigmented GS as compared to controls (p<0.005), whereas for patients having cholesterol and mixed GS the concentrations were on the lower side. Biliary Ca concentrations of patients were found to be higher than controls, but difference was significant for pigmented GS patients (p>0.001). The contents of Cu and Fe in serum and bile of all patients (except female cholesterol GS patient have low serum iron concentration) were found to be higher than control, but difference was significant in those patients who have pigmented GS. The concentration of Ca, Fe and Cu in different types GS were found in the order, Pigmented>mixed>cholesterol. The bile/serum ratio for Ca, Cu and Fe was found to be significantly higher in pigmented GS patients. Gall bladder bile was slightly alkaline in patients as compared to referents. The density of bile was found to be higher in patients as compared to the referents. Various functional groups present in different types of GS samples were confirmed by Fourier

Indirect Redox Transformations of Iron, Copper, and Chromium Catalyzed by Extremely Acidophilic Bacteria

PubMed Central

Johnson, D. Barrie; Hedrich, Sabrina; Pakostova, Eva

2017-01-01

Experiments were carried out to examine redox transformations of copper and chromium by acidophilic bacteria (Acidithiobacillus, Leptospirillum, and Acidiphilium), and also of iron (III) reduction by Acidithiobacillus spp. under aerobic conditions. Reduction of iron (III) was found with all five species of Acidithiobacillus tested, grown aerobically on elemental sulfur. Cultures maintained at pH 1.0 for protracted periods displayed increasing propensity for aerobic iron (III) reduction, which was observed with cell-free culture liquors as well as those containing bacteria. At. caldus grown on hydrogen also reduced iron (III) under aerobic conditions, confirming that the unknown metabolite(s) responsible for iron (III) reduction were not (exclusively) sulfur intermediates. Reduction of copper (II) by aerobic cultures of sulfur-grown Acidithiobacillus spp. showed similar trends to iron (III) reduction in being more pronounced as culture pH declined, and occurring in both the presence and absence of cells. Cultures of Acidithiobacillus grown anaerobically on hydrogen only reduced copper (II) when iron (III) (which was also reduced) was also included; identical results were found with Acidiphilium cryptum grown micro-aerobically on glucose. Harvested biomass of hydrogen-grown At. ferridurans oxidized iron (II) but not copper (I), and copper (I) was only oxidized by growing cultures of Acidithiobacillus spp. when iron (II) was also included. The data confirmed that oxidation and reduction of copper were both mediated by acidophilic bacteria indirectly, via iron (II) and iron (III). No oxidation of chromium (III) by acidophilic bacteria was observed even when, in the case of Leptospirillum spp., the redox potential of oxidized cultures exceeded +900 mV. Cultures of At. ferridurans and A. cryptum reduced chromium (VI), though only when iron (III) was also present, confirming an indirect mechanism and contradicting an earlier report of direct chromium reduction by A

Determination of adsorptive and catalytic properties of copper, silver and iron contain titanium-pillared bentonite for the removal bisphenol A from aqueous solution

NASA Astrophysics Data System (ADS)

Tomul, Fatma; Turgut Basoglu, Funda; Canbay, Hale

2016-01-01

Ti-pillared bentonite, Cu, Ag and Fe modified Ti-pillared bentonite and Cu/Ti- and Fe/Ti-mixed pillared bentonite were synthesized using different titanium sources by direct synthesis or by modification after synthesis. The effects of synthesis conditions on the surface characteristics, pore structure and acidity of the pillared bentonites were investigated by SEM⿿EDS, XPS, XRD, N2-adsorption/desorption and FTIR analyses before and after ammonia adsorption. The results of EDS, XPS and XRD analysis confirmed that titanium, copper, silver and iron were incorporated into the bentonite structure. In the XRD patterns, the formation of delaminated structure reflecting the non-parallel distribution of the bentonite layers by pillaring with Ti, Cu/Ti and Fe/Ti-pillars was observed. XPS spectra indicated the presence of TiO2, CuO, Ag and Ag2O and Fe2O3 species depending on the source of active metals in the synthesized samples. In the FTIR spectra, an increase in the Bronsted/Lewis peak intensity was observed with the loading of copper and iron, whereas a decrease in Lewis and Bronsted acidities was observed with incorporation of silver. Adsorption studies indicated that the adsorption capacity of the sample synthesized using titanium (IV) propoxide and incorporating iron to the structure by ion exchange (Fe-PTi-PILC) were higher than those in other samples. The adsorption of BPA (bisphenol A) by all tested samples was found to fit the Langmuir isotherm. In the catalytic wet peroxide oxidation (CWPO) over PTi-PILC (prepared by titanium (IV) propoxide), Fe-PTi-PILC and Cu-PTi-PILC (prepared by copper impregnated Ti-pillared bentonite) samples, BPA values close to complete conversion were achieved within 30 min at 25 °C, pH 4 and 5 g/L mcat. CWPO results showed that increasement of pH causes a decrease the rate of oxidation. On the other hand, by the time catalyst and BPA concentration is increased, the rate of oxidation is increased as well.

Impairment of Interrelated Iron- and Copper Homeostatic Mechanisms in Brain Contributes to the Pathogenesis of Neurodegenerative Disorders

PubMed Central

Skjørringe, Tina; Møller, Lisbeth Birk; Moos, Torben

2012-01-01

Iron and copper are important co-factors for a number of enzymes in the brain, including enzymes involved in neurotransmitter synthesis and myelin formation. Both shortage and an excess of iron or copper will affect the brain. The transport of iron and copper into the brain from the circulation is strictly regulated, and concordantly protective barriers, i.e., the blood-brain barrier (BBB) and the blood-cerebrospinal fluid (CSF) barrier (BCB) have evolved to separate the brain environment from the circulation. The uptake mechanisms of the two metals interact. Both iron deficiency and overload lead to altered copper homeostasis in the brain. Similarly, changes in dietary copper affect the brain iron homeostasis. Moreover, the uptake routes of iron and copper overlap each other which affect the interplay between the concentrations of the two metals in the brain. The divalent metal transporter-1 (DMT1) is involved in the uptake of both iron and copper. Furthermore, copper is an essential co-factor in numerous proteins that are vital for iron homeostasis and affects the binding of iron-response proteins to iron-response elements in the mRNA of the transferrin receptor, DMT1, and ferroportin, all highly involved in iron transport. Iron and copper are mainly taken up at the BBB, but the BCB also plays a vital role in the homeostasis of the two metals, in terms of sequestering, uptake, and efflux of iron and copper from the brain. Inside the brain, iron and copper are taken up by neurons and glia cells that express various transporters. PMID:23055972

Electrodeposition of CuZn Alloys from the Non-Cyanide Alkaline Baths

NASA Astrophysics Data System (ADS)

Li, Minggang; Wei, Guoying; Hu, Shuangshuang; Xu, Shuhan; Yang, Yejiong; Miao, Qinfang

2015-10-01

Effect of copper sulfate on CuZn alloys electroplating from non-cyanide baths are investigated by different electrochemical methods. Cyclic voltammetry and current transient measurements are used to characterize the CuZn alloys electroplating system in order to analyze the nucleation and growth mechanism. The reduction of Cu and CuZn alloy on sheet iron substrates shows an instantaneous nucleation process. However, the reduction of Zn on sheet iron substrates shows a progressive nucleation process. The structure and surface morphology of CuZn alloys are analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The morphology of CuZn alloys obtained with 50 g L-1 copper sulfate presents a smooth and compact deposit and the size of crystal particle is uniform.

Reactivity of food phenols with iron and copper ions: binding, dioxygen activation and oxidation mechanisms.

PubMed

Nkhili, Ezzohra; Loonis, Michèle; Mihai, Simona; El Hajji, Hakima; Dangles, Olivier

2014-06-01

In this work, the affinity of common dietary phenols (gallic acid, caffeic acid, catechin, and rutin) for iron and copper ions was quantitatively investigated in neutral phosphate buffer as well as the reactivity of the complexes toward dioxygen. Contrasting behaviors were observed: because of the competing phosphate ions, Fe(III) binding is much slower than Fe(II) binding, which is rapidly followed by autoxidation of Fe(II) into Fe(III). With both ions, O2 consumption and H2O2 production are modest and the phenolic ligands are only slowly oxidized. By contrast, metal-phenol binding is fast with both Cu(I) and Cu(II). With Cu(I), O2 consumption and H2O2 production are very significant and the phenolic ligands are rapidly oxidized into a complex mixture of oligomers. The corresponding mechanism with Cu(II) is hampered by the preliminary rate-determining step of Cu(II) reduction by the phenols. The consequences of these findings for the stability and antioxidant activity of plant phenols are discussed.

Transcuprein is a Macroglobulin Regulated by Copper and Iron Availability

PubMed Central

Liu, Nanmei; Lo, Louis Shi-li; Askary, S. Hassan; Jones, LaTrice; Kidane, Theodros Z.; Nguyen, Trisha Trang Minh; Goforth, Jeremy; Chu, Yu-Hsiang; Vivas, Esther; Tsai, Monta; Westbrook, Terence; Linder, Maria C.

2009-01-01

SUMMARY Transcuprein is a high affinity copper carrier in the plasma involved in the initial distribution of copper entering the blood from the digestive tract. To identify and obtain cDNA for this protein, it was purified from rat plasma by size exclusion and copper chelate affinity chromatography, and amino acid sequences were obtained. These revealed a 190 kDa glycosylated protein identified as the macroglobulin, α1inhibitorIII, the main macroglobulin of rodent blood plasma. Albumin (65 kDa) co-purified in variable amounts and was concluded to be a contaminant (although it transiently can bind the macroglobulin). The main macroglobulin in human blood plasma (α2-macroglobulin), homologous to α1inhibitorIII, also bound copper tightly. Expression of α1I3 (transcuprein) mRNA by the liver was examined in rats with and without copper deficiency, using quantitative PCR and Northern analysis. Protein expression was examined by Western blotting. Deficient rats with 40% less ceruloplasmin oxidase activity and liver copper concentrations expressed about twice as much α1I3 mRNA, but circulating levels of transcuprein did not differ. Iron deficiency, which increased liver copper concentrations 3-fold, reduced transcuprein mRNA expression and 7circulating levels of transcuprein relative to what occurred in rats with normal or excess iron. We conclude that transcupreins are specific macroglobulins that not only carry zinc but also transport copper in the blood; and that their expression can be modulated by copper and iron availability. PMID:17363239

Differential affinity of BsSCO for Cu(II) and Cu(I) suggests a redox role in copper transfer to the Cu(A) center of cytochrome c oxidase.

PubMed

Hill, Bruce C; Andrews, Diann

2012-06-01

SCO (synthesis of cytochrome c oxidase) proteins are involved in the assembly of the respiratory chain enzyme cytochrome c oxidase acting to assist in the assembly of the Cu(A) center contained within subunit II of the oxidase complex. The Cu(A) center receives electrons from the reductive substrate ferrocytochrome c, and passes them on to the cytochrome a center. Cytochrome a feeds electrons to the oxygen reaction site composed of cytochrome a(3) and Cu(B). Cu(A) consists of two copper ions positioned within bonding distance and ligated by two histidine side chains, one methionine, a backbone carbonyl and two bridging cysteine residues. The complex structure and redox capacity of Cu(A) present a potential assembly challenge. SCO proteins are members of the thioredoxin family which led to the early suggestion of a disulfide exchange function for SCO in Cu(A) assembly, whereas the copper binding capacity of the Bacillus subtilis version of SCO (i.e., BsSCO) suggests a direct role for SCO proteins in copper transfer. We have characterized redox and copper exchange properties of apo- and metalated-BsSCO. The release of copper (II) from its complex with BsSCO is best achieved by reducing it to Cu(I). We propose a mechanism involving both disulfide and copper exchange between BsSCO and the apo-Cu(A) site. This article is part of a Special Issue entitled: Biogenesis/Assembly of Respiratory Enzyme Complexes. Copyright © 2011 Elsevier B.V. All rights reserved.

Photoelectron and computational studies of the copper-nucleoside anionic complexes, Cu(-)(cytidine) and Cu(-)(uridine).

PubMed

Li, Xiang; Ko, Yeon-Jae; Wang, Haopeng; Bowen, Kit H; Guevara-García, Alfredo; Martínez, Ana

2011-02-07

The copper-nucleoside anions, Cu(-)(cytidine) and Cu(-)(uridine), have been generated in the gas phase and studied by both experimental (anion photoelectron spectroscopy) and theoretical (density functional calculations) methods. The photoelectron spectra of both systems are dominated by single, intense, and relatively narrow peaks. These peaks are centered at 2.63 and 2.71 eV for Cu(-)(cytidine) and Cu(-)(uridine), respectively. According to our calculations, Cu(-)(cytidine) and Cu(-)(uridine) species with these peak center [vertical detachment energy (VDE)] values correspond to structures in which copper atomic anions are bound to the sugar portions of their corresponding nucleosides largely through electrostatic interactions; the observed species are anion-molecule complexes. The combination of experiment and theory also reveal the presence of a slightly higher energy, anion-molecule complex isomer in the case of the Cu(-)(cytidine). Furthermore, our calculations found that chemically bond isomers of these species are much more stable than their anion-molecule complex counterparts, but since their calculated VDE values are larger than the photon energy used in these experiments, they were not observed.

Photoelectron and computational studies of the copper-nucleoside anionic complexes, Cu-(cytidine) and Cu-(uridine)

NASA Astrophysics Data System (ADS)

Li, Xiang; Ko, Yeon-Jae; Wang, Haopeng; Bowen, Kit H.; Guevara-García, Alfredo; Martínez, Ana

2011-02-01

The copper-nucleoside anions, Cu-(cytidine) and Cu-(uridine), have been generated in the gas phase and studied by both experimental (anion photoelectron spectroscopy) and theoretical (density functional calculations) methods. The photoelectron spectra of both systems are dominated by single, intense, and relatively narrow peaks. These peaks are centered at 2.63 and 2.71 eV for Cu-(cytidine) and Cu-(uridine), respectively. According to our calculations, Cu-(cytidine) and Cu-(uridine) species with these peak center [vertical detachment energy (VDE)] values correspond to structures in which copper atomic anions are bound to the sugar portions of their corresponding nucleosides largely through electrostatic interactions; the observed species are anion-molecule complexes. The combination of experiment and theory also reveal the presence of a slightly higher energy, anion-molecule complex isomer in the case of the Cu-(cytidine). Furthermore, our calculations found that chemically bond isomers of these species are much more stable than their anion-molecule complex counterparts, but since their calculated VDE values are larger than the photon energy used in these experiments, they were not observed.

Adsorption of low concentration ceftazidime from aqueous solutions using impregnated activated carbon promoted by Iron, Copper and Aluminum

NASA Astrophysics Data System (ADS)

Hu, Xiang; Zhang, Hua; Sun, Zhirong

2017-01-01

In this paper, three impregnated activated carbon IAC (AC-Cu, AC-Fe, and AC-Al) promoted by Iron, Copper and Aluminum were used for adsorption of ceftazidime. Iron(III), Copper(II) and Aluminum(III) nitrate were used as an impregnant. The IACs were characterized by scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET) surface area analyzer, Fourier transform infrared spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS).The influence of factors, such as ion strength, pH, temperature, initial concentration, and concentration of natural organic matter organic matter on the adsorption process were studied. The adsorption kinetics and isotherms of ceftazidime were studied for the three IACs. The results showed that the adsorption was accurately represented by pseudo-second order model. Under different temperature, the maximum adsorption quantity of ceftazidime on AC-Cu calculated by pseudo-second order kinetic model were 200.0 mg g-1 (298 K), 196.1 mg g-1 (303 K) and 185.2 mg g-1 (308 K). It was much higher than that of AC-Fe and AC-Al. And the process was controlled by both film diffusion and intra particle mass transport. The results also showed that, the Freundlich and Temkin isotherm fit the adsorption well.

Organic Complexation of Dissolved Copper and Iron from Shipboard Incubations in the Central California Current System: Investigating the Impacts of Light Conditions and Phytoplankton Growth on Iron- and Copper-Binding Ligand Characteristics

NASA Astrophysics Data System (ADS)

Mellett, T.; Parker, C.; Brown, M.; Coale, T.; Duckham, C.; Chappell, D.; Maldonado, M. T.; Bruland, K. W.; Buck, K. N.

2016-02-01

Two shipboard incubation experiments were carried out in July of 2014 to investigate potential sources and sinks of iron- and copper-binding organic ligands in the surface ocean. Seawater for the experiments was collected from the central California Current System (cCCS) and incubated under varying light conditions and in the presence and absence of natural phytoplankton communities. Incubation treatments were sampled over a period of up to 3 days for measurements of total dissolved copper and iron, and for the concentration and conditional stability constants of copper- and iron-binding organic ligands. Dissolved copper and iron were determined by inductively coupled plasma-mass spectrometry (ICP-MS) following preconcentration on a Nobias PA1 resin. Organic ligand characteristics for iron and copper were determined using a method of competitive ligand exchange-absorptive cathodic stripping voltammetry (CLE-ACSV) with the added competing ligand salicylaldoxime. Trends in ligand concentrations and conditional stability constants across the different treatments and over the course of the incubation experiments will be presented.

CELLULAR MULTITASKING: THE DUAL ROLE OF HUMAN CU-ATPASES IN COFACTOR DELIVERY AND INTRACELLULAR COPPER BALANCE

PubMed Central

Lutsenko, Svetlana; Gupta, Arnab; Burkhead, Jason L.; Zuzel, Vesna

2008-01-01

Summary The human copper-transporting ATPases (Cu-ATPases) are essential for dietary copper uptake, normal development and function of the CNS, and regulation of copper homeostasis in the body. In a cell, Cu-ATPases maintain the intracellular concentration of copper by transporting copper into intracellular exocytic vesicles. In addition, these P-type ATPases mediate delivery of copper to copper-dependent enzymes in the secretory pathway and in specialized cell compartments such as secretory granules or melanosomes. The multiple functions of human Cu-ATPase necessitate complex regulation of these transporters that is mediated through the presence of regulatory domains in their structure, posttranslational modification and intracellular trafficking, as well as interactions with the copper chaperone Atox1 and other regulatory molecules. In this review, we summarize the current information on the function and regulatory mechanisms acting on human Cu-ATPases ATP7A and ATP7B. Brief comparison with the Cu-ATPase orthologues from other species is included. PMID:18534184

Assessing the combination of iron sulfate and organic materials as amendment for an arsenic and copper contaminated soil. A chemical and ecotoxicological approach.

PubMed

Fresno, Teresa; Moreno-Jiménez, Eduardo; Peñalosa, Jesús M

2016-12-01

The efficiency of combining iron sulfate and organic amendments (paper mill sludge, olive mill waste compost and olive tree pruning biochar) for the remediation of an As- and Cu-contaminated soil was evaluated. Changes in As and Cu fractionation and solubility due to the application of the amendments was explored by leachate analysis, single and sequential extractions. Also, the effects on Arrhenatherum elatius growth, germination of Lactuca sativa and toxicity to the bacteria Vibrio fischeri were assessed. The combination of iron sulfate and the organic amendments efficiently reduced As solubility and availability through the formation of amorphous iron oxides, while organic matter did not seem to mobilize As. At the same time, copper fractionation was strongly affected by soil pH and organic matter addition. The soil pH significantly influenced both As and Cu mobility. Within all the amendments tested, FeSO 4 in combination with compost showed to be the most suitable treatment for the overall remediation process, as it reduced As and Cu availability andenhanced soil nutrient concentrations and plant growth. In sipte of contradictory trends between chemical analyses and ecotoxicity tests, we can still conclude that the application of organic amendments in combination with reactive iron salts is a suitable approach for the remediation of soils contaminated by Cu and As. Copyright © 2016 Elsevier Ltd. All rights reserved.

Removal of copper ions from aqueous solutions by a steel-making by-product.

PubMed

López, F A; Martín, M I; Pérez, C; López-Delgado, A; Alguacil, F J

2003-09-01

A study is made of the use of a steel-making by-product (rolling mill scale) as a material for removing Cu(2+) ions from aqueous solutions. The influence of contact time, initial copper ion concentration and temperature on removal capability is considered. The removal of Cu(2+) ions from an aqueous solution involves two processes: on the one hand, the adsorption of Cu(2+) ions on the surface of mill scale due to the iron oxides present in the latter; and on the other hand, the cementation of Cu(2+) onto metallic iron contained in the mill scale. Rolling mill scale is seen to be an effective material for the removal of copper ions from aqueous solutions.

Fabrication and applications of copper sulfide (CuS) nanostructures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shamraiz, Umair, E-mail: umairshamraiz@gmail.com; Hussain, Raja Azadar, E-mail: hussainazadar@gamil.com; Badshah, Amin, E-mail: aminbadshah@yahoo.com

2016-06-15

This review article presents different fabrication procedures (under the headlines of solvothermal routes, aerosol methods, solution methods and thermolysis), and applications (photocatalytic degradation, ablation of cancer cells, electrode material in lithium ion batteries and in gas sensing, organic solar cells, field emission properties, super capacitor applications, photoelectrochemical performance of QDSCs, photocatalytic reduction of organic pollutants, electrochemical bio sensing, enhanced PEC characteristics of pre-annealed CuS film electrodes) of copper sulfide (Covellite). - Highlights: • This review article presents the synthesis and applications of copper sulfide. • CuS has been used over the years for different applications in nanoscience. • Different syntheticmore » protocols are followed for their preparation which help in the possible modifications in the morphology of CuS.« less

Transcriptome Sequencing Identifies SPL7-Regulated Copper Acquisition Genes FRO4/FRO5 and the Copper Dependence of Iron Homeostasis in Arabidopsis[C][W

PubMed Central

Bernal, María; Casero, David; Singh, Vasantika; Wilson, Grandon T.; Grande, Arne; Yang, Huijun; Dodani, Sheel C.; Pellegrini, Matteo; Huijser, Peter; Connolly, Erin L.; Merchant, Sabeeha S.; Krämer, Ute

2012-01-01

The transition metal copper (Cu) is essential for all living organisms but is toxic when present in excess. To identify Cu deficiency responses comprehensively, we conducted genome-wide sequencing-based transcript profiling of Arabidopsis thaliana wild-type plants and of a mutant defective in the gene encoding SQUAMOSA PROMOTER BINDING PROTEIN-LIKE7 (SPL7), which acts as a transcriptional regulator of Cu deficiency responses. In response to Cu deficiency, FERRIC REDUCTASE OXIDASE5 (FRO5) and FRO4 transcript levels increased strongly, in an SPL7-dependent manner. Biochemical assays and confocal imaging of a Cu-specific fluorophore showed that high-affinity root Cu uptake requires prior FRO5/FRO4-dependent Cu(II)-specific reduction to Cu(I) and SPL7 function. Plant iron (Fe) deficiency markers were activated in Cu-deficient media, in which reduced growth of the spl7 mutant was partially rescued by Fe supplementation. Cultivation in Cu-deficient media caused a defect in root-to-shoot Fe translocation, which was exacerbated in spl7 and associated with a lack of ferroxidase activity. This is consistent with a possible role for a multicopper oxidase in Arabidopsis Fe homeostasis, as previously described in yeast, humans, and green algae. These insights into root Cu uptake and the interaction between Cu and Fe homeostasis will advance plant nutrition, crop breeding, and biogeochemical research. PMID:22374396

Eu3 + amidst ionic copper in glass: Enhancement through energy transfer from Cu+, or quenching by Cu2 +?

NASA Astrophysics Data System (ADS)

Jiménez, José A.

2017-02-01

A barium-phosphate glass system doped with europium(III) and containing a high concentration of copper(I) together with a copper(II) remnant has been studied spectroscopically. The main object is to elucidate whether the orange-red emission of Eu3 + ions succeeds through sensitization via luminescent Cu+ ions or else is preferentially quenched by non-radiative transfer to Cu2 +. A characterization of the melt-quenched glass was first performed by UV/Vis optical absorption, 31P nuclear magnetic resonance and infrared absorption spectroscopy. A photoluminescence (PL) spectroscopy and emission decay dynamics assessment was subsequently performed. Despite the concentration of Cu+ being estimated to be much higher than that of Cu2 +, the data shows that quenching of Eu3 + PL by Cu2 + dominates. The lifetime analysis of emitting centers Cu+ and Eu3 + points to the origin of the manifestation being that the Eu3 + → Cu2 + non-radiative transfer rate responsible for the quenching is almost two times higher than that for the Cu+ → Eu3 + transfer accountable for the enhancement. Finally, an effort was made for the determination of Cu2 + in the glass containing Cu+, Cu2 + and Eu3 + ions based on the Eu3 + (5D0) emission decay rates. It was found to be in excellent agreement with the UV/Vis spectrophotometric approach, thus supporting the utility of Eu3 + ions for optical sensing of copper(II) in the solid state.

Rapid synthesis of Fe-doped CuO-Ce0.8Zr0.2O2 catalysts for CO preferential oxidation in H2-rich streams: Effect of iron source and the ratio of Fe/Cu

NASA Astrophysics Data System (ADS)

Wang, Jing; Han, Caiyun; Gao, Xiaoya; Lu, Jichang; Wan, Gengpin; He, Dedong; Chen, Ran; Chen, Kezhen; He, Sufang; Luo, Yongming

2017-03-01

A facile route (urea grind combustion method) is described for the rapid synthesis of Fe-doped Cu-Ce-Zr catalysts within 30 min through simple grinding and combustion. The effects of iron source and Fe/Cu mass ratio on the performances of the catalysts for CO preferential oxidation (CO-PROX) are evaluated. The influences of H2O, CO2, and their mixture on the activity as well as stability of the catalysts are also investigated. The samples are characterized by XRD, N2 adsorption-desorption, H2-TPR, TEM, Raman and XPS. Fe(NO3)3 is found to be superior to FeCl3 and Fe2(SO4)3 as the iron source for Fe-CuCZ catalyst. Among the different synthesized catalysts, 1/10Fe(N)-CuCZ is found to be the most active catalyst, indicating that the optimal Fe/Cu mass ratio is 1/10. The influences of H2O, CO2, and H2O + CO2 on the catalytic performance of 1/10Fe(N)-CuCZ are in the order of CO2 < CO2 + H2O < H2O. 1/10Fe(N)-CuCZ exhibits excellent stability during a 228 h time-on-stream test. 1/10Fe(N)-CuCZ shows the highest catalytic activity and excellent stability even in the presence of H2O and CO2. The excellent catalytic performance can be attributed to the synergy between the highly dispersed copper species and ceria, as well as the formation of more oxygen vacancies and reduced copper species.

The Stoichiometry of Isoquercitrin Complex with Iron or Copper Is Highly Dependent on Experimental Conditions

PubMed Central

Tvrdý, Václav; Karlíčková, Jana; Migkos, Thomas; Mladěnka, Přemysl

2017-01-01

Interaction of flavonoids with transition metals can be partially responsible for their impact on humans. Stoichiometry of the iron/copper complex with a flavonoid glycoside isoquercitrin, a frequent component of food supplements, was assessed using competitive and non-competitive methods in four (patho)physiologically-relevant pH values (4.5. 5.5, 6.8, and 7.5). Isoquercitrin chelated all tested ions (Fe2+, Fe3+, Cu2+, and Cu+) but its affinity for Cu+ ions proved to be very low. In general, the chelation potency dropped with pH lowering. Metal complexes of 1:1 stoichiometry were mostly formed, however, they were not stable and the stoichiometry changed depending on conditions. Isoquercitrin was able to reduce both Cu2+ and Fe3+ ions at low ratios, but its reducing potential was diminished at higher ratios (isoquercitrin to metal) due to the metal chelation. In conclusion, this study emphasizes the need of using multiple different methods for the assessment of chelation potential in moderately-active metal chelators, like flavonoids. PMID:29084179

Cu-rGO subsurface layer creation on copper substrate and its resistance to oxidation

NASA Astrophysics Data System (ADS)

Pietrzak, Katarzyna; Strojny-Nędza, Agata; Olesińska, Wiesława; Bańkowska, Anna; Gładki, Andrzej

2017-11-01

On the basis of a specially designed experiment, this paper presents a model, which is an attempt to explain the mechanism of formatting and creating oxidation resistance of Cu-rGO subsurface layers. Practically zero chemical affinity of copper to carbon is a fundamental difficulty in creating composite structures of Cu-C, properties which are theoretically possible to estimate. In order to bind the thermally reduced graphene oxide with copper surface, the effect of structural rebuilding of the copper oxide, in the process of annealing in a nitrogen atmosphere, have been used. On intentionally oxidized and anoxic copper substrates the dispersed graphene oxide (GO) and thermally reduced graphene oxide (rGO) were loaded. Annealing processes after the binding effects of both graphene oxide forms to Cu substrates were tested. The methods for high-resolution electron microscopy were found subsurface rGO-Cu layer having a substantially greater resistance to oxidation than pure copper. The mechanism for the effective resistance to oxidation of the Cu-rGO has been presented in a hypothetical form.

Cu(I)-mediated Allosteric Switching in a Copper-sensing Operon Repressor (CsoR)*

PubMed Central

Chang, Feng-Ming James; Coyne, H. Jerome; Cubillas, Ciro; Vinuesa, Pablo; Fang, Xianyang; Ma, Zhen; Ma, Dejian; Helmann, John D.; García-de los Santos, Alejandro; Wang, Yun-Xing; Dann, Charles E.; Giedroc, David P.

2014-01-01

The copper-sensing operon repressor (CsoR) is representative of a major Cu(I)-sensing family of bacterial metalloregulatory proteins that has evolved to prevent cytoplasmic copper toxicity. It is unknown how Cu(I) binding to tetrameric CsoRs mediates transcriptional derepression of copper resistance genes. A phylogenetic analysis of 227 DUF156 protein members, including biochemically or structurally characterized CsoR/RcnR repressors, reveals that Geobacillus thermodenitrificans (Gt) CsoR characterized here is representative of CsoRs from pathogenic bacilli Listeria monocytogenes and Bacillus anthracis. The 2.56 Å structure of Cu(I)-bound Gt CsoR reveals that Cu(I) binding induces a kink in the α2-helix between two conserved copper-ligating residues and folds an N-terminal tail (residues 12–19) over the Cu(I) binding site. NMR studies of Gt CsoR reveal that this tail is flexible in the apo-state with these dynamics quenched upon Cu(I) binding. Small angle x-ray scattering experiments on an N-terminally truncated Gt CsoR (Δ2–10) reveal that the Cu(I)-bound tetramer is hydrodynamically more compact than is the apo-state. The implications of these findings for the allosteric mechanisms of other CsoR/RcnR repressors are discussed. PMID:24831014

Distribution and mobility of exogenous copper as influenced by aging and components interactions in three Chinese soils.

PubMed

Shi, Hanzhi; Li, Qi; Chen, Wenli; Cai, Peng; Huang, Qiaoyun

2018-04-01

Copper contamination of soils is a global environmental problem. Soil components (organic matter, clay minerals, and microorganisms) and retention time can govern the adsorption, fixation, and distribution of copper. This study evaluated the interaction effects of soil components and aging on the distribution of exogenous copper. Three typical Chinese soils (Ultisol, Alfisol, and Histosol) were collected from Hunan, Henan, and Heilongjiang Provinces. Soils were incubated with rice straw (RS) and engineered bacteria (Pseudomonas putida X4/pIME) in the presence of exogenous copper for 12 months. Sequential extraction was employed to obtain the distribution of Cu species in soils, and the mobility factors of Cu were calculated. The relationships between soil properties and Cu fractions were analyzed with stepwise multiple linear regression. The results show that organic carbon plays a more important role in shaping the distribution of relatively mobile Cu, and iron oxides can be more critical in stabilizing Cu species in soils. Our results suggest that organic matter is the most important factor influencing copper partitioning in Ultisols, while iron oxides are more significant in Alfisols. The mobility of exogenous Cu in soils depends largely on organic carbon, amorphous Fe, and aging. The introduction of both rice straw and rice straw + engineered bacteria enhanced the stabilization of Cu in all the three soils during aging process. The introduction of bacteria could reduce copper mobility, which was indicated by the lowest mobility factors of Cu for the treatment with bacteria in Black, Red, and Cinnamon soils at the first 4, 8, and 8 months, respectively. Different measures should be taken into account regarding the content of organic matter and iron oxides depending on soil types for the risk assessment and remediation of Cu-contaminated soils.

Nanoscale Zero-Valent Iron Decorated on Bentonite/Graphene Oxide for Removal of Copper Ions from Aqueous Solution.

PubMed

Shao, Jicheng; Yu, Xiaoniu; Zhou, Min; Cai, Xiaoqing; Yu, Chuang

2018-06-04

The removal efficiency of Cu(II) in aqueous solution by bentonite, graphene oxide (GO), and nanoscale iron decorated on bentonite (B-nZVI) and nanoscale iron decorated on bentonite/graphene oxide (GO-B-nZVI) was investigated. The results indicated that GO-B-nZVI had the best removal efficiency in different experimental environments (with time, pH, concentration of copper ions, and temperature). For 16 hours, the removal efficiency of copper ions was 82% in GO-B-nZVI, however, it was 71% in B-nZVI, 26% in bentonite, and 18% in GO. Bentonite, GO, B-nZVI, and GO-B-nZVI showed an increased removal efficiency of copper ions with the increase of pH under a certain pH range. The removal efficiency of copper ions by GO-B-nZVI first increased and then fluctuated slightly with the increase of temperature, while B-nZVI and bentonite increased and GO decreased slightly with the increase of temperature. Lorentz-Transmission Electron Microscope (TEM) images showed the nZVI particles of GO-B-nZVI dispersed evenly with diameters ranging from 10 to 86.93 nm. Scanning electron microscope (SEM) images indicated that the nanoscale iron particles were dispersed evenly on bentonite and GO with no obvious agglomeration. The q e,cal (73.37 mg·g -1 and 83.89 mg·g -1 ) was closer to the experimental value q e,exp according to the pseudo-second-order kinetic model. The q m of B-nZVI and GO-B-nZVI were 130.7 mg·g -1 and 184.5 mg·g -1 according to the Langmuir model.

Development of copper recovery process from flotation tailings by a combined method of high‒pressure leaching‒solvent extraction.

PubMed

Han, Baisui; Altansukh, Batnasan; Haga, Kazutoshi; Stevanović, Zoran; Jonović, Radojka; Avramović, Ljiljana; Urosević, Daniela; Takasaki, Yasushi; Masuda, Nobuyuki; Ishiyama, Daizo; Shibayama, Atsushi

2018-06-15

Sulfide copper mineral, typically Chalcopyrite (CuFeS 2 ), is one of the most common minerals for producing metallic copper via the pyrometallurgical process. Generally, flotation tailings are produced as a byproduct of flotation and still consist of un‒recovered copper. In addition, it is expected that more tailings will be produced in the coming years due to the increased exploration of low‒grade copper ores. Therefore, this research aims to develop a copper recovery process from flotation tailings using high‒pressure leaching (HPL) followed by solvent extraction. Over 94.4% copper was dissolved from the sample (CuFeS 2 as main copper mineral) by HPL in a H 2 O media in the presence of pyrite, whereas the iron was co‒dissolved with copper according to an equation given as C Cu  = 38.40 × C Fe . To avoid co‒dissolved iron giving a negative effect on the subsequent process of electrowinning, solvent extraction was conducted on the pregnant leach solution for improving copper concentration. The result showed that 91.3% copper was recovered in a stripped solution and 98.6% iron was removed under the optimal extraction conditions. As a result, 86.2% of copper was recovered from the concentrate of flotation tailings by a proposed HPL‒solvent extraction process. Copyright © 2018 Elsevier B.V. All rights reserved.

Accumulation, distribution, and toxicity of copper in sediments of catfish ponds receiving periodic copper sulfate applications.

PubMed

Han, F X; Hargreaves, J A; Kingery, W L; Huggett, D B; Schlenk, D K

2001-01-01

Copper sulfate (CuSO4) is applied periodically to commercial channel catfish (Ictalurus panctatus) ponds as an algicide or parasiticide. Current understanding of the chemistry of copper in soil-water systems suggests that copper may accumulate in pond sediments, although the forms and potential bioavailability of copper in catfish pond sediments are not known. This study investigated the accumulation and distribution of copper in the sediment of catfish ponds receiving periodic additions of CuSO4.5H2O. All ponds were constructed in Sharkey (very-fine, smectitic, thermic Chromic Epiaquert) soil. Nine 0.40-ha ponds received 59 applications of 2.27 kg CuSO4.5H2O per application per pond over 3 yr; no CuSO4.5H2O applications were made to nine additional ponds. Total Cu concentration in the sediments of CuSO4.5H2O-amended catfish ponds (172.5 mg kg(-1)) was four to five times higher than that in the sediments of nonamended ponds (36.1 mg kg(-1)). Copper accumulated in catfish pond sediments at a rate of 41 microg kg(-1) dry sediment for each 1 kg ha(-1) of CuSO4. 5H2O applied to ponds. Copper in the sediments of amended ponds was mainly in the organic matter-bound (30.7%), carbonate-bound (31.8%), and amorphous iron oxide-bound (22.1%) fractions with a considerable fraction (3.4%; 3 to 8 mg kg(-1)) in soluble and exchangeable fractions. This indicates that Cu accumulates differentially in various fractions, with proportionally greater initial accumulation in potentially bioavailable forms. However, toxicity bioassays with amphipods (Hyallela azteca) and common cattail (Typha latifolia L.) indicated that the effect of exposure to amended or nonamended pond sediments was not different.

Copper Ion from Cu2O Crystal Induces AMPK-Mediated Autophagy via Superoxide in Endothelial Cells

PubMed Central

Seo, Youngsik; Cho, Young-Sik; Huh, Young-Duk; Park, Heonyong

2016-01-01

Copper is an essential element required for a variety of functions exerted by cuproproteins. An alteration of the copper level is associated with multiple pathological conditions including chronic ischemia, atherosclerosis and cancers. Therefore, copper homeostasis, maintained by a combination of two copper ions (Cu+ and Cu2+), is critical for health. However, less is known about which of the two copper ions is more toxic or functional in endothelial cells. Cubic-shaped Cu2O and CuO crystals were prepared to test the role of the two different ions, Cu+ and Cu2+, respectively. The Cu2O crystal was found to have an effect on cell death in endothelial cells whereas CuO had no effect. The Cu2O crystals appeared to induce p62 degradation, LC3 processing and an elevation of LC3 puncta, important processes for autophagy, but had no effect on apoptosis and necrosis. Cu2O crystals promote endothelial cell death via autophagy, elevate the level of reactive oxygen species such as superoxide and nitric oxide, and subsequently activate AMP-activated protein kinase (AMPK) through superoxide rather than nitric oxide. Consistently, the AMPK inhibitor Compound C was found to inhibit Cu2O-induced AMPK activation, p62 degradation, and LC3 processing. This study provides insight on the pathophysiologic function of Cu+ ions in the vascular system, where Cu+ induces autophagy while Cu2+ has no detected effect. PMID:26743904

Copper and ectopic expression of the Arabidopsis transport protein COPT1 alter iron homeostasis in rice (Oryza sativa L.).

PubMed

Andrés-Bordería, Amparo; Andrés, Fernando; Garcia-Molina, Antoni; Perea-García, Ana; Domingo, Concha; Puig, Sergi; Peñarrubia, Lola

2017-09-01

Copper deficiency and excess differentially affect iron homeostasis in rice and overexpression of the Arabidopsis high-affinity copper transporter COPT1 slightly increases endogenous iron concentration in rice grains. Higher plants have developed sophisticated mechanisms to efficiently acquire and use micronutrients such as copper and iron. However, the molecular mechanisms underlying the interaction between both metals remain poorly understood. In the present work, we study the effects produced on iron homeostasis by a wide range of copper concentrations in the growth media and by altered copper transport in Oryza sativa plants. Gene expression profiles in rice seedlings grown under copper excess show an altered expression of genes involved in iron homeostasis compared to standard control conditions. Thus, ferritin OsFER2 and ferredoxin OsFd1 mRNAs are down-regulated whereas the transcriptional iron regulator OsIRO2 and the nicotianamine synthase OsNAS2 mRNAs rise under copper excess. As expected, the expression of OsCOPT1, which encodes a high-affinity copper transport protein, as well as other copper-deficiency markers are down-regulated by copper. Furthermore, we show that Arabidopsis COPT1 overexpression (C1 OE ) in rice causes root shortening in high copper conditions and under iron deficiency. C1 OE rice plants modify the expression of the putative iron-sensing factors OsHRZ1 and OsHRZ2 and enhance the expression of OsIRO2 under copper excess, which suggests a role of copper transport in iron signaling. Importantly, the C1 OE rice plants grown on soil contain higher endogenous iron concentration than wild-type plants in both brown and white grains. Collectively, these results highlight the effects of rice copper status on iron homeostasis, which should be considered to obtain crops with optimized nutrient concentrations in edible parts.

Three-dimensional atlas of iron, copper, and zinc in the mouse cerebrum and brainstem.

PubMed

Hare, Dominic J; Lee, Jason K; Beavis, Alison D; van Gramberg, Amanda; George, Jessica; Adlard, Paul A; Finkelstein, David I; Doble, Philip A

2012-05-01

Atlases depicting molecular and functional features of the brain are becoming an integral part of modern neuroscience. In this study we used laser ablation-inductively coupled plasma-mass spectrometry (LA-ICPMS) to quantitatively measure iron (Fe), copper (Cu), and zinc (Zn) levels in a serially sectioned C57BL/6 mouse brain (cerebrum and brainstem). Forty-six sections were analyzed in a single experiment of approximately 158 h in duration. We constructed a 46-plate reference atlas by aligning quantified images of metal distribution with corresponding coronal sections from the Allen Mouse Brain Reference Atlas. The 46 plates were also used to construct three-dimensional models of Fe, Cu, and Zn distribution. This atlas represents the first reconstruction of quantitative trace metal distribution through the brain by LA-ICPMS and will facilitate the study of trace metals in the brain and help to elucidate their role in neurobiology.

Formation of nickel and copper ferrites in ceramics: a potential reaction in the reuse of iron-rich sludge incineration ash.

PubMed

Shih, Kaimin

2012-12-01

This study investigates potential solid-state reactions for the stabilization of hazardous metals when reusing the incineration ash from chemically enhanced primary treatment (CEPT) sludge to fabricate ceramic products. Nickel and copper were used as examples of hazardous metals, and the iron content in the reaction system was found to play a major role in incorporating these hazardous metals into their ferrite phases (NiFe2O4 and CuFe2O4). The results from three-hour sintering experiments on NiO + Fe2O3 and CuO + Fe2O3 systems clearly demonstrate the potential for initiating metal incorporation mechanisms using an iron-containing precursor at attainable ceramic sintering temperatures (above 750 degrees C). Both ferrite phases were examined using a prolonged leaching experiment modified from the widely used toxicity characteristic leaching procedure (TCLP) to evaluate their long-term metal leachability. The leaching results indicate that both the NiFe2O4 and the CuFe2O4 products were significantly superior to their oxide forms in immobilizing hazardous metals.

Removal of copper and iron by polyurethane foam column in FIA system for the determination of nickel in pierced ring.

PubMed

Vongboot, Monnapat; Suesoonthon, Monrudee

2015-01-01

Polyurethane foam (PUF) mini-column was used to eliminate copper and iron for the determination of nickel in pierced rings. The PUF mini-column was connected to FIA system for on-line sorption of copper and iron in complexes form of CuSCN(+) and FeSCN(2+). For this season, the acid solution containing a mixture of Ni(II), Fe(III), Cu(II) and SCN(-) ions was firstly flew into the PUF column. Then, the percolated solution which Fe(III) and Cu(II) ions is separated from analysis was injected into FIA system to react with 4-(2-pyridylazo) resorcinol (PAR) reagent in basic condition which this method is called pH gradient technique. The Ni-PAR complexes obtained were measured theirs absorbance at 500 nm by UV visible spectrophotometer. In this study, it was found that Cu(II) and Fe(III) were completely to form complexes with 400 mmol/L KSCN and entirely to eliminate in acidic condition at pH 3.0. In the optimum condition of these experiments, the method provided the linear relationship between absorbance and the concentration of Ni(II) in the range from 5.00 to 30.00 mg/L. Linear equation is y=0.0134x+0.0033 (R(2)=0.9948). Precision, assessed in the term of the relative standard deviation, RSD, and accuracy for multiple determinations obtained in values of 0.77-1.73% and 97.4%, respectively. The level of an average amount of Ni(II) in six piercing rings was evaluated to be 14.78 mg/g. Copyright © 2014 Elsevier B.V. All rights reserved.

Studies of concentration and temperature dependences of precipitation kinetics in iron-copper alloys using kinetic Monte Carlo and stochastic statistical simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khromov, K. Yu.; Vaks, V. G., E-mail: vaks@mbslab.kiae.ru; Zhuravlev, I. A.

2013-02-15

The previously developed ab initio model and the kinetic Monte Carlo method (KMCM) are used to simulate precipitation in a number of iron-copper alloys with different copper concentrations x and temperatures T. The same simulations are also made using an improved version of the previously suggested stochastic statistical method (SSM). The results obtained enable us to make a number of general conclusions about the dependences of the decomposition kinetics in Fe-Cu alloys on x and T. We also show that the SSM usually describes the precipitation kinetics in good agreement with the KMCM, and using the SSM in conjunction withmore » the KMCM allows extending the KMC simulations to the longer evolution times. The results of simulations seem to agree with available experimental data for Fe-Cu alloys within statistical errors of simulations and the scatter of experimental results. Comparison of simulation results with experiments for some multicomponent Fe-Cu-based alloys allows making certain conclusions about the influence of alloying elements in these alloys on the precipitation kinetics at different stages of evolution.« less

Oxidation Potentials in Matte Smelting of Copper and Nickel

NASA Astrophysics Data System (ADS)

Matousek, Jan W.

2014-09-01

The oxidation potential, given as the base-ten logarithm of the oxygen partial pressure in bars and the temperature [log pO2/ T, °C], defines the state of oxidation of pyrometallurgical extraction and refining processes. This property varies from copper making, [-6/1150]; to lead/zinc smelting, [-10/1200]; to iron smelting, [-13/1600]. The current article extends the analysis to the smelting of copper and nickel/copper sulfide concentrates to produce mattes of the type Cu(Ni)FeS(O) and iron silicate slags, FeOxSiO2—with oxidation potentials of [-7.5/1250].

Serum ceruloplasmin protein expression and activity increases in iron-deficient rats and is further enhanced by higher dietary copper intake

PubMed Central

Ranganathan, Perungavur N.; Lu, Yan; Jiang, Lingli; Kim, Changae

2011-01-01

Increases in serum and liver copper content are noted during iron deficiency in mammals, suggesting that copper-dependent processes participate during iron deprivation. One point of intersection between the 2 metals is the liver-derived, multicopper ferroxidase ceruloplasmin (Cp) that is important for iron release from certain tissues. The current study sought to explore Cp expression and activity during physiologic states in which hepatic copper loading occurs (eg, iron deficiency). Weanling rats were fed control or low iron diets containing low, normal, or high copper for ∼ 5 weeks, and parameters of iron homeostasis were measured. Liver copper increased in control and iron-deficient rats fed extra copper. Hepatic Cp mRNA levels did not change; however, serum Cp protein was higher during iron deprivation and with higher copper consumption. In-gel and spectrophotometric ferroxidase and amine oxidase assays demonstrated that Cp activity was enhanced when hepatic copper loading occurred. Interestingly, liver copper levels strongly correlated with Cp protein expression and activity. These observations support the possibility that liver copper loading increases metallation of the Cp protein, leading to increased production of the holo enzyme. Moreover, this phenomenon may play an important role in the compensatory response to maintain iron homeostasis during iron deficiency. PMID:21768302

Copper Deficiency Leads to Anemia, Duodenal Hypoxia, Upregulation of HIF-2α and Altered Expression of Iron Absorption Genes in Mice

PubMed Central

Matak, Pavle; Zumerle, Sara; Mastrogiannaki, Maria; El Balkhi, Souleiman; Delga, Stephanie; Mathieu, Jacques R. R.; Canonne-Hergaux, François; Poupon, Joel; Sharp, Paul A.; Vaulont, Sophie; Peyssonnaux, Carole

2013-01-01

Iron and copper are essential trace metals, actively absorbed from the proximal gut in a regulated fashion. Depletion of either metal can lead to anemia. In the gut, copper deficiency can affect iron absorption through modulating the activity of hephaestin - a multi-copper oxidase required for optimal iron export from enterocytes. How systemic copper status regulates iron absorption is unknown. Mice were subjected to a nutritional copper deficiency-induced anemia regime from birth and injected with copper sulphate intraperitoneally to correct the anemia. Copper deficiency resulted in anemia, increased duodenal hypoxia and Hypoxia inducible factor 2α (HIF-2α) levels, a regulator of iron absorption. HIF-2α upregulation in copper deficiency appeared to be independent of duodenal iron or copper levels and correlated with the expression of iron transporters (Ferroportin - Fpn, Divalent Metal transporter – Dmt1) and ferric reductase – Dcytb. Alleviation of copper-dependent anemia with intraperitoneal copper injection resulted in down regulation of HIF-2α-regulated iron absorption genes in the gut. Our work identifies HIF-2α as an important regulator of iron transport machinery in copper deficiency. PMID:23555700

Fate and forms of Cu in a reservoir ecosystem following copper sulfate treatment (Saint Germain les Belles, France)

NASA Astrophysics Data System (ADS)

van Hullebusch, E.; Chatenet, P.; Deluchat, V.; Chazal, P. M.; Froissard, D.; Lens, P. N. L.; Baudu, M.

2003-05-01

Copper sulfate (CuSO4) addition to freshwater for phytoplankton control has been practiced for decades, and remains the most effective algicidal treatment for numerous managed water bodies. A reservoir in the centre of France was the site for an investigation of copper distribution in aquatic systems after a copper sulfate treatment Results of copper monitoring showed a rapid conversion of dissolved Cu to particulate forms, with significant accumulation in the sediments/83% of total copper added). Total sediment Cu content increasedfrom approximately 37.7 to 45.4 μg.g^{-1} dry weight after the first treatment. Sequential extraction suggested that a significanl portion of the sediment-borne Cu was associated with the organic fraction which may release Cu to the water column, although significant release would occur only under extreme changes in water chemistry. Based upon measured Cu concentrations, flows at the down-stream water, and known mass applied during treatment, mass balance calculations indicated that approximately 17% of the Cu was exported from the reservoir over a 70 day period following a 196 μg.L^{-l} Cu^{2+} (as CuSO4, 5 H2O) treatment. The largest amount of copper was probably adsorbed on downstream sediment or lost in running water, Copper bioaccumulation by a moss, Fontinalis antipyretica, in the down-stream water showed that it was possible to distinguish between a treated and an untreated area. The impact of copper treatment in the down-stream reservoir could be followed using mosses. The bioaccumulation data further showed that there is a distance effect which could be exploited to determine potential copper impact on receiving water bodies. Thirty days after copper sulfate addition, Fontinalis still indicated copper exposure.

Chemical speciation and bioavailability of Cu(II). Study of the ionic copper(II) and bis(glycinate)-copper(II) accumulation by Lemna species

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benda, F.; Kouba, J.

1991-03-01

In this paper, the authors examined the accumulation of copper(II) in, and its toxic effect on, duckweed, a plant which exhibits extremely high concentration factors. The effect of copper(II) was investigated by adding it to the minimal medium in two forms: CuSO{sub 4} and (Cu(Gly){sub 2}). The neutral (2:1) tetracoordinated bis(glycinate)-copper(II) complex is constituted by two five-membered rings bonded to the central copper atom with the cis configuration. This complex was chosen to model the function of a neutral species (eliminating the charge effect) involving a nontoxic ligand, for which - in contrast to the hydrated Cu{sup 2+} species -more » direct permeation through the cell wall is conceivable.« less

Syntheses and structural characterization of iron(II) and copper(II) coordination compounds with the neutral flexible bidentate N-donor ligands

NASA Astrophysics Data System (ADS)

Beheshti, Azizolla; Lalegani, Arash; Bruno, Giuseppe; Rudbari, Hadi Amiri

2014-08-01

Two new coordination compounds [Fe(bib)2(N3)2]n(1) and [Cu2(bpp)2(N3)4] (2) with azide and flexible ligands 1,4-bis(imidazolyl)butane (bib) and 1,3-bis(3,5-dimethylpyrazolyl)propane (bpp) were prepared and structurally characterized. In the 2D network structure of 1, the iron(II) ion lies on an inversion center and exhibits an FeN6 octahedral arrangement while in the dinuclear structure of 2, the copper(II) ion adopts an FeN5 distorted square pyramid geometry. In the complex 1, each μ2-bib acts as bridging ligand connecting two adjacent iron(II) ions while in the complex 2, the bpp ligand is coordinated to copper(II) ion in a cyclic-bidentate fashion forming an eight-membered metallocyclic ring. Coordination compounds 1 and 2 have been characterized by infrared spectroscopy, elemental analyses and single-crystal X-ray diffraction. Thermal analysis of polymer 1 was also studied.

Cellular and molecular responses of adult zebrafish after exposure to CuO nanoparticles or ionic copper.

PubMed

Vicario-Parés, Unai; Lacave, Jose M; Reip, Paul; Cajaraville, Miren P; Orbea, Amaia

2018-01-01

Due to their antimicrobial, electrical and magnetic properties, copper nanoparticles (NPs) are suitable for a vast array of applications. Copper can be toxic to biota, making it necessary to assess the potential hazard of copper nanomaterials. Zebrafish (Danio rerio) were exposed to 10 µg Cu/L of CuO NPs of ≈100 nm (CuO-poly) or ionic copper to compare the effects provoked after 3 and 21 days of exposure and at 6 months post-exposure (mpe). At 21 days, significant copper accumulation was only detected in fish exposed to ionic copper. Exposure to both copper forms caused histopathological alterations that could reduce gill functionality, more markedly in the case of ionic copper. Nevertheless, at 6 mpe higher prevalences of gill lesions were detected in fish previously exposed to CuO-poly NPs. No relevant histological alterations were detected in liver, but the lysosomal membrane stability test showed significantly impaired general health status after exposure to both metal forms that lasted up to 6 mpe. 69 transcripts appeared regulated after 3 days of exposure to CuO-poly NPs, suggesting that NPs could produce oxidative stress and reduce metabolism and transport processes. Thirty transcripts were regulated after 21 days of exposure to ionic copper, indicating possible DNA damage. Genes of the circadian clock were identified as the key genes involved in time-dependent differences between the two copper forms. In conclusion, each copper form showed a distinct pattern of liver transcriptome regulation, but both caused gill histopathological alterations and long lasting impaired health status in adult zebrafish.

Arabidopsis copper transport protein COPT2 participates in the cross talk between iron deficiency responses and low-phosphate signaling.

PubMed

Perea-García, Ana; Garcia-Molina, Antoni; Andrés-Colás, Nuria; Vera-Sirera, Francisco; Pérez-Amador, Miguel A; Puig, Sergi; Peñarrubia, Lola

2013-05-01

Copper and iron are essential micronutrients for most living organisms because they participate as cofactors in biological processes, including respiration, photosynthesis, and oxidative stress protection. In many eukaryotic organisms, including yeast (Saccharomyces cerevisiae) and mammals, copper and iron homeostases are highly interconnected; yet, such interdependence is not well established in higher plants. Here, we propose that COPT2, a high-affinity copper transport protein, functions under copper and iron deficiencies in Arabidopsis (Arabidopsis thaliana). COPT2 is a plasma membrane protein that functions in copper acquisition and distribution. Characterization of the COPT2 expression pattern indicates a synergic response to copper and iron limitation in roots. We characterized a knockout of COPT2, copt2-1, that leads to increased resistance to simultaneous copper and iron deficiencies, measured as reduced leaf chlorosis and improved maintenance of the photosynthetic apparatus. We propose that COPT2 could play a dual role under iron deficiency. First, COPT2 participates in the attenuation of copper deficiency responses driven by iron limitation, possibly to minimize further iron consumption. Second, global expression analyses of copt2-1 versus wild-type Arabidopsis plants indicate that low-phosphate responses increase in the mutant. These results open up new biotechnological approaches to fight iron deficiency in crops.

Copper-catalyzed azide–alkyne cycloaddition (CuAAC) and beyond: new reactivity of copper(i) acetylides†

PubMed Central

Hein, Jason E.

2011-01-01

Copper-catalyzed azide–alkyne cycloaddition (CuAAC) is a widely utilized, reliable, and straightforward way for making covalent connections between building blocks containing various functional groups. It has been used in organic synthesis, medicinal chemistry, surface and polymer chemistry, and bioconjugation applications. Despite the apparent simplicity of the reaction, its mechanism involves multiple reversible steps involving coordination complexes of copper(i) acetylides of varying nuclearity. Understanding and controlling these equilibria is of paramount importance for channeling the reaction into the productive catalytic cycle. This tutorial review examines the history of the development of the CuAAC reaction, its key mechanistic aspects, and highlights the features that make it useful to practitioners in different fields of chemical science. PMID:20309487

Characterization and recovery of copper values from discarded slag.

PubMed

Das, Bisweswar; Mishra, Barada Kanta; Angadi, Shivakumar; Pradhan, Siddharth Kumar; Prakash, Sandur; Mohanty, Jayakrushna

2010-06-01

In any copper smelter large quantities of copper slag are discarded as waste material causing space and environmental problems. This discarded slag contains important amounts of metallic values such as copper and iron. The recovery of copper values from an Indian smelter slag that contains 1.53% Cu, 39.8% Fe and 34.65% SiO(2) was the focus of the present study. A complete investigation of the different phases present in the slag has been carried out by means of optical microscopy, Raman spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) techniques. It is observed that iron and silica are mostly associated with the fayalite phase whereas copper is present in both oxide and sulfide phases. These oxide and sulfide phases of copper are mostly present within the slag phase and to some extent the slag is also embedded inside the oxide and sulfide phases. The recovery of copper values from the discarded slag has been explored by applying a flotation technique using conventional sodium isopropyl xanthate (SIX) as the collector. The effects of flotation parameters such as pH and collector concentration are investigated. Under optimum flotation conditions, it is possible to achieve 21% Cu with more than 80% recovery.

Photoelectron and computational studies of the copper-nucleoside anionic complexes, Cu{sup -}(cytidine) and Cu{sup -}(uridine)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li Xiang; Ko, Yeon-Jae; Wang Haopeng

2011-02-07

The copper-nucleoside anions, Cu{sup -}(cytidine) and Cu{sup -}(uridine), have been generated in the gas phase and studied by both experimental (anion photoelectron spectroscopy) and theoretical (density functional calculations) methods. The photoelectron spectra of both systems are dominated by single, intense, and relatively narrow peaks. These peaks are centered at 2.63 and 2.71 eV for Cu{sup -}(cytidine) and Cu{sup -}(uridine), respectively. According to our calculations, Cu{sup -}(cytidine) and Cu{sup -}(uridine) species with these peak center [vertical detachment energy (VDE)] values correspond to structures in which copper atomic anions are bound to the sugar portions of their corresponding nucleosides largely through electrostaticmore » interactions; the observed species are anion-molecule complexes. The combination of experiment and theory also reveal the presence of a slightly higher energy, anion-molecule complex isomer in the case of the Cu{sup -}(cytidine). Furthermore, our calculations found that chemically bond isomers of these species are much more stable than their anion-molecule complex counterparts, but since their calculated VDE values are larger than the photon energy used in these experiments, they were not observed.« less

Age-dependent changes of cerebral copper metabolism in Atp7b -/- knockout mouse model of Wilson's disease by [64Cu]CuCl2-PET/CT.

PubMed

Xie, Fang; Xi, Yin; Pascual, Juan M; Muzik, Otto; Peng, Fangyu

2017-06-01

Copper is a nutritional metal required for brain development and function. Wilson's disease (WD), or hepatolenticular degeneration, is an inherited human copper metabolism disorder caused by a mutation of the ATP7B gene. Many WD patients present with variable neurological and psychiatric symptoms, which may be related to neurodegeneration secondary to copper metabolism imbalance. The objective of this study was to explore the feasibility and use of copper-64 chloride ([ 64 C]CuCl 2 ) as a tracer for noninvasive assessment of age-dependent changes of cerebral copper metabolism in WD using an Atp7b -/- knockout mouse model of WD and positron emission tomography/computed tomography (PET/CT) imaging. Continuing from our recent study of biodistribution and radiation dosimetry of [ 64 C]CuCl 2 in Atp7b -/- knockout mice, PET quantitative analysis revealed low 64 Cu radioactivity in the brains of Atp7b -/- knockout mice at 7th weeks of age, compared with 64 Cu radioactivity in the brains of age- and gender-matched wild type C57BL/6 mice, at 24 h (h) post intravenous injection of [ 64 C]CuCl 2 as a tracer. Furthermore, age-dependent increase of 64 Cu radioactivity was detected in the brains of Atp7b -/- knockout mice from the 13th to 21th weeks of age, based on the data derived from a longitudinal [ 64 C]CuCl 2 -PET/CT study of Atp7b -/- knockout mice with orally administered [ 64 Cu]CuCl 2 as a tracer. The findings of this study support clinical use of [ 64 Cu]CuCl 2 -PET/CT imaging as a tool for noninvasive assessment of age-dependent changes of cerebral copper metabolism in WD patients presenting with variable neurological and psychiatric symptoms.

Influence of CuSO4 and chelated copper algaecide exposures on biodegradation of microcystin-LR.

PubMed

Iwinski, Kyla J; Rodgers, John H; Kinley, Ciera M; Hendrikse, Maas; Calomeni, Alyssa J; McQueen, Andrew D; Geer, Tyler D; Liang, Jenny; Friesen, Vanessa; Haakensen, Monique

2017-05-01

Copper exposures from algaecide applications in aquatic systems are hypothesized to impede bacterial degradation of microcystin (MC), a cyanobacterial produced hepatotoxin. Despite regulatory implications of this hypothesis, limited data exist on influences of copper-exposures on MC-degrading bacteria and consequent MC-degradation. In this study, influences of copper-algaecide concentrations and formulations on bacterial composition and microcystin-LR (MCLR) degradation were investigated. Microcystis aeruginosa was exposed to four concentrations (0-5.0 mg Cu L -1 ) of three copper-algaecide formulations, and rates and extents of MCLR degradation were measured. In untreated controls and following exposures of 0.1, 0.5, and 1.0 mg Cu L -1 , MCLR concentrations decreased at a rate of ∼41-53 μg MCLR/L d -1 . Following exposure to 5.0 mg Cu L -1 MCLR degradation rates decreased an order of magnitude to ∼3-7 μg MCLR/L d -1 . Bacterial diversity decreased following copper-exposures greater than 0.1 mg Cu L -1 for all formulations. Relative abundance of certain groups of MC-degrading bacteria identified in treatments increased with increasing copper concentration, suggesting they may be less sensitive to copper exposures than other, MCLR and non MC-degrading heterotrophic bacteria present in the assemblage. Results from this study revealed that copper concentration can influence degradation rates of MCLR, however this influence was not significant within copper concentrations currently registered for use (≤1.0 mg Cu L -1 ) of the tested algaecides. Copper formulation did not significantly alter degradation rates or bacterial composition. These data augment our understanding of the influences of copper algaecide-exposures on MCLR degradation, and can be used to inform more accurate risk evaluations and use of copper-algaecides for management of MCLR-producing cyanobacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

Lenticular nucleus hyperechogenicity in Wilson's disease reflects local copper, but not iron accumulation.

PubMed

Walter, Uwe; Skowrońska, Marta; Litwin, Tomasz; Szpak, Grażyna Maria; Jabłonka-Salach, Katarzyna; Skoloudík, David; Bulska, Ewa; Członkowska, Anna

2014-10-01

In patients with Wilson's disease (WD) transcranial brain sonography typically reveals areas of increased echogenicity (hyperechogenicity) of the lenticular nucleus (LN). Correlation with T2-hypointensity on magnetic resonance images suggested that LN hyperechogenicity in WD is caused by trace metal accumulation. Accumulation of both, copper and iron, in the brain of WD patients has been reported. The present study was designed to elucidate whether LN hyperechogenicity in WD reflects accumulation of copper or iron. Post-mortem brains of 15 WD patients and one non-WD subject were studied with ultrasonography in an investigator-blinded fashion. LN hyperechogenicity was measured planimetrically by manual tracing as well as using digitized image analysis. The putaminal copper content was determined in samples of 11 WD brains and the non-WD brains using inductively coupled plasma mass spectrometry, and iron content was assessed using flame atomic absorption spectroscopy. LN was normal on ultrasonography only in the non-WD brain, but abnormal (hyperechogenic) in all WD brains. Digitized image analysis measures of LN hyperechogenicity and, by trend, manual measures correlated with putaminal copper content (Pearson test; digitized: r = 0.77, p = 0.04; manual: r = 0.57, p = 0.051) but not with iron content (each, p > 0.18). LN hyperechogenicity measures were unrelated to age at death of patients, age at onset of WD, WD duration, age of brain specimen, serum copper or serum ceruloplasmin (each, p > 0.1). We conclude that LN hyperechogenicity in WD reflects copper, but not iron accumulation. Further studies are warranted to elucidate the use of transcranial brain sonography for monitoring therapeutic effects of chelating agents in WD patients.

Contrasting Physiological and Proteomic Adaptations to Iron and/or Copper Limitation in Two Strains of the Same Open Ocean Diatom Thalassiosira oceanica

NASA Astrophysics Data System (ADS)

Schuback, N.; Hippmann, A.; Maldonado, M. T.; Allen, A. E.; McCrow, J.; Foster, L. J.; Green, B. R.; Alami, M.

2016-02-01

Iron plays a significant role in controlling marine primary productivity. Despite that extremely low dissolved iron (Fe) concentrations are found in Fe-limited regions, some phytoplankton are able to survive and thrive. Two strains of the model oceanic diatom Thalassiosira oceanica, TO 1003 and TO 1005, have both been used in previous studies to characterize adaptations to iron limitation. These studies have shown that T. oceanica has lowered its Fe requirements and increased its Fe acquisition efficiency compared to coastal counterparts. Both strategies may impose a higher cellular copper (Cu) demand. However, the underlying biochemical adaptations in these oceanic diatoms remain unknown. Recently, the genome, as well as the first proteomic and transcriptomic analyses of T. oceanica 1005 grown under different Fe levels, were published. To further our understanding of the interplay between Fe- and Cu- physiology in open ocean diatoms, we examined an array of physiological responses to varying degrees of Fe-, Cu- and Fe/Cu co-limitation in both strains. We also determined the differential expression of proteins using stable isotope labeling and LC-MS/MS proteomic analysis. The two strains, TO 1003 and TO 1005, need markedly different metal concentrations in the media. TO1003 requires 30% less Cu to sustain its optimal growth and less than 1/10th of the minimum Cu that is needed by TO 1005 to survive. In contrast, TO 1005 is able to grow with less Fe available in the media. The physiological and proteomic responses of these two strains when acclimated to low Fe and/or Cu concentrations will be presented. The evolutionary implications will be discussed.

Bioextraction of Copper from Printed Circuit Boards: Influence of Initial Concentration of Ferrous Iron

NASA Astrophysics Data System (ADS)

Yamane, Luciana Harue; Espinosa, Denise Crocce Romano; Tenório, Jorge Alberto Soares

Printed circuit boards are found in all electric and electronic equipment and are particularly problematic to recycle because of the heterogeneous mix of organic material, metals, and fiberglass. Additionally, printed circuit boards can be considered a secondary source of copper and bacterial leaching can be applied to copper recovery. This study investigated the influence of initial concentration of ferrous iron on bacterial leaching to recover copper from printed circuit boards using Acidithiobacillus ferrooxidans-LR. Printed circuit boards from computers were comminuted using a hammer mill. The powder obtained was magnetically separated and the non magnetic material used in this study. A shake flask study was carried out on the non magnetic material using a rotary shaker at 30°C, 170 rpm and different initial concentrations of ferrous iron (gL-1): 6.75; 13.57 and 16.97. Abiotic controls were also run in parallel. The monitored parameters were pH, Eh, ferrous iron concentration and copper extraction (spectroscopy of atomic absorption). The results showed that using initial concentration of ferrous iron of 6.75gL-1 were extracted 99% of copper by bacterial leaching.

iron phase control during pressure leaching at elevated temperature

NASA Astrophysics Data System (ADS)

Fleuriault, Camille

Iron is a common contaminant encountered in most metal recovery operations, and particularly hydrometallurgical processes. For example, the Hematite Process uses autoclaves to precipitate iron oxide out of the leaching solution, while other metals are solubilized for further hydrometallurgical processing. In some cases, Basic Iron Sulfate (BIS) forms in place of hematite. The presence of BIS is unwanted in the autoclave discharge because it diminishes recovery and causes environmental matters. The focus of this master thesis is on the various iron phases forming during the pressure oxidation of sulfates. Artificial leaching solutions were produced from CuSO4, FeSO4 and H2SO4 in an attempt to recreate the matrix composition and conditions used for copper sulfides autoclaving. The following factors were investigated in order to determine which conditions hinder the formation of BIS: initial free acidity (5 -- 98 g/L), initial copper concentration (12.7 -- 63.5 g/L), initial iron concentration (16.7 -- 30.7 g/L) and initial iron oxidation state. There were three solid species formed in the autoclave: hematite, BIS and hydronium jarosite. The results show that free acid is the main factor influencing the composition of the residue. At an initial concentration of 22.3 g/L iron and no copper added, the upper limit for iron oxide formation is 41 g/L H2SO4. The increase of BIS content in the residue is not gradual and occurs over a change of a few grams per liter around the aforementioned limit. Increasing copper sulfate concentration in the solution hinders the formation of BIS. At 63.5g/L copper, the upper free acidity limit is increased to 61g/L. This effect seems to be related to the buffering action of copper sulfate, decreasing the overall acid concentration and thus extending the stability range of hematite. The effect of varying iron concentration on the precipitate chemistry is unclear. At high iron levels, the only noticeable effect was the inhibition of jarosite

Hydrogenation of CO 2 on ZnO/Cu(100) and ZnO/Cu(111) Catalysts: Role of Copper Structure and Metal–Oxide Interface in Methanol Synthesis

DOE PAGES

Palomino, Robert M.; Ramirez, Pedro J.; Liu, Zongyuan; ...

2017-08-21

The results of kinetic tests and ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) show the important role played by a ZnO–copper interface in the generation of CO and the synthesis of methanol from CO 2 hydrogenation. The deposition of nanoparticles of ZnO on Cu(100) and Cu(111), θ oxi < 0.3 monolayer, produces highly active catalysts. The catalytic activity of these systems increases in the sequence: Cu(111) < Cu(100) < ZnO/Cu(111) < ZnO/Cu(100). The structure of the copper substrate influences the catalytic performance of a ZnO–copper interface. Furthermore, size and metal–oxide interactions affect the chemical and catalytic properties of the oxide making themore » supported nanoparticles different from bulk ZnO. The formation of a ZnO–copper interface favors the binding and conversion of CO 2 into a formate intermediate that is stable on the catalyst surface up to temperatures above 500 K. Alloys of Zn with Cu(111) and Cu(100) were not stable at the elevated temperatures (500–600 K) used for the CO 2 hydrogenation reaction. However, reaction with CO 2 oxidized the zinc, enhancing its stability over the copper substrates.« less

Hydrogenation of CO 2 on ZnO/Cu(100) and ZnO/Cu(111) Catalysts: Role of Copper Structure and Metal–Oxide Interface in Methanol Synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palomino, Robert M.; Ramirez, Pedro J.; Liu, Zongyuan

The results of kinetic tests and ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) show the important role played by a ZnO–copper interface in the generation of CO and the synthesis of methanol from CO 2 hydrogenation. The deposition of nanoparticles of ZnO on Cu(100) and Cu(111), θ oxi < 0.3 monolayer, produces highly active catalysts. The catalytic activity of these systems increases in the sequence: Cu(111) < Cu(100) < ZnO/Cu(111) < ZnO/Cu(100). The structure of the copper substrate influences the catalytic performance of a ZnO–copper interface. Furthermore, size and metal–oxide interactions affect the chemical and catalytic properties of the oxide making themore » supported nanoparticles different from bulk ZnO. The formation of a ZnO–copper interface favors the binding and conversion of CO 2 into a formate intermediate that is stable on the catalyst surface up to temperatures above 500 K. Alloys of Zn with Cu(111) and Cu(100) were not stable at the elevated temperatures (500–600 K) used for the CO 2 hydrogenation reaction. However, reaction with CO 2 oxidized the zinc, enhancing its stability over the copper substrates.« less

Rat liver mitochondrial dysfunction by addition of copper(II) or iron(III) ions.

PubMed

Saporito-Magriñá, Christian; Musacco-Sebio, Rosario; Acosta, Juan M; Bajicoff, Sofía; Paredes-Fleitas, Paola; Boveris, Alberto; Repetto, Marisa G

2017-01-01

Increased copper (Cu) and iron (Fe) levels in liver and brain are associated to oxidative stress and damage with increased phospholipid oxidation process. The aim of this work was to assess the toxic effects of Cu 2+ and Fe 3+ addition to rat liver mitochondria by determining mitochondrial respiration in states 3 (active respiration) and 4 (resting respiration), and phospholipid peroxidation. Both, Cu 2+ and Fe 3+ produced decreases in O 2 consumption in a concentration-dependent manner in active state 3: both ions by 42% with malate-glutamate as complex I substrate (concentration for half maximal response (C 50 ) 60μM Cu 2+ and 1.25mM Fe 3+ ), and with succinate as complex II substrate: 64-69% with C 50 of 50μM Cu 2+ and with C 50 of 1.25mM of Fe 3+ . Respiratory control decreased with Cu 2+ (C 50 50μM) and Fe 3+ (C 50 1.25-1-75mM) with both substrates. Cu 2+ produced a 2-fold increase and Fe 3+ a 5-fold increase of thiobarbituric acid-reactive substances (TBARS) content from 25μM Cu 2+ (C 50 40μM) and from 100μM Fe 3+ (C 50 1.75mM). Supplementations with Cu 2+ and Fe 3+ ions induce mitochondrial dysfunction with phospholipid peroxidation in rat liver mitochondria. Although is proved that a Fenton/Haber Weiss mechanism of oxidative damage occurs in metal-ion induced mitochondrial toxicity, slightly different responses to the metal ions suggest some differences in the mechanism of intracellular toxicity. The decreased rates of mitochondrial respiration and the alteration of mitochondrial function by phospholipid and protein oxidations lead to mitochondrial dysfunction, cellular dyshomeostasis and cell death. Copyright © 2016 Elsevier Inc. All rights reserved.

Reaction Mechanisms of Metals with Hydrogen Sulfide and Thiols in Model Wine. Part 2: Iron- and Copper-Catalyzed Oxidation.

PubMed

Kreitman, Gal Y; Danilewicz, John C; Jeffery, David W; Elias, Ryan J

2016-05-25

Sulfidic off-odors arising during wine production are frequently removed by Cu(II) fining. In part 1 of this study ( 10.1021/acs.jafc.6b00641 ), the reaction of H2S and thiols with Cu(II) was examined; however, the interaction of iron and copper is also known to play an important synergistic role in mediating non-enzymatic wine oxidation. The interaction of these two metals in the oxidation of H2S and thiols (cysteine, 3-sulfanylhexan-1-ol, and 6-sulfanylhexan-1-ol) was therefore examined under wine-like conditions. H2S and thiols (300 μM) were reacted with Fe(III) (100 or 200 μM) alone and in combination with Cu(II) (25 or 50 μM), and concentrations of H2S and thiols, oxygen, and acetaldehyde were monitored over time. H2S and thiols were shown to be slowly oxidized in the presence of Fe(III) alone and were not bound to Fe(III) under model wine conditions. However, Cu(II) added to model wine containing Fe(III) was quickly reduced by H2S and thiols to form Cu(I) complexes, which then rapidly reduced Fe(III) to Fe(II). Oxidation of Fe(II) in the presence of oxygen regenerated Fe(III) and completed the iron redox cycle. In addition, sulfur-derived oxidation products were observed, and the formation of organic polysulfanes was demonstrated.

Copper Sensing Function of Drosophila Metal-Responsive Transcription Factor-1 Is Mediated By a Tetranuclear Cu(I) Cluster

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, X.; Hua, H.; Balamurugan, K.

2009-05-12

Drosophila melanogaster MTF-1 (dMTF-1) is a copper-responsive transcriptional activator that mediates resistance to Cu, as well as Zn and Cd. Here, we characterize a novel cysteine-rich domain which is crucial for sensing excess intracellular copper by dMTF-1. Transgenic flies expressing mutant dMTF-1 containing alanine substitutions of two, four or six cysteine residues within the sequence {sup 547}CNCTNCKCDQTKSCHGGDC{sup 565} are significantly or completely impaired in their ability to protect flies from copper toxicity and fail to up-regulate MtnA (metallothionein) expression in response to excess Cu. In contrast, these flies exhibit wild-type survival in response to copper deprivation thus revealing that themore » cysteine cluster domain is required only for sensing Cu load by dMTF-1. Parallel studies show that the isolated cysteine cluster domain is required to protect a copper-sensitive S. cerevisiae ace1 strain from copper toxicity. Cu(I) ligation by a Cys-rich domain peptide fragment drives the cooperative assembly of a polydentate [Cu{sub 4}-S{sub 6}] cage structure, characterized by a core of trigonally S{sub 3} coordinated Cu(I) ions bound by bridging thiolate ligands. While reminiscent of Cu{sub 4}-L{sub 6} (L = ligand) tetranuclear clusters in copper regulatory transcription factors of yeast, the absence of significant sequence homology is consistent with convergent evolution of a sensing strategy particularly well suited for Cu(I).« less

Carbon monoxide oxidation over three different states of copper: Development of a model metal oxide catalyst

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jernigan, Glenn Geoffrey

1994-10-01

Carbon monoxide oxidation was performed over the three different oxidation states of copper -- metallic (Cu), copper (I) oxide (Cu 2O), and copper (II) oxide (CuO) as a test case for developing a model metal oxide catalyst amenable to study by the methods of modern surface science and catalysis. Copper was deposited and oxidized on oxidized supports of aluminum, silicon, molybdenum, tantalum, stainless steel, and iron as well as on graphite. The catalytic activity was found to decrease with increasing oxidation state (Cu > Cu 2O > CuO) and the activation energy increased with increasing oxidation state (Cu, 9 kcal/molmore » < Cu 2O, 14 kcal/mol < CuO, 17 kcal/mol). Reaction mechanisms were determined for the different oxidation states. Lastly, NO reduction by CO was studied. A Cu and CuO catalyst were exposed to an equal mixture of CO and NO at 300--350 C to observe the production of N 2 and CO 2. At the end of each reaction, the catalyst was found to be Cu 2O. There is a need to study the kinetics of this reaction over the different oxidation states of copper.« less

Measurements of serum non-ceruloplasmin copper by a direct fluorescent method specific to Cu(II).

PubMed

Squitti, Rosanna; Siotto, Mariacristina; Cassetta, Emanuele; El Idrissi, Imane Ghafir; Colabufo, Nicola A

2017-08-28

Meta-analyses indicated the breakdown of copper homeostasis in the sporadic form of Alzheimer's disease (AD), comprising copper decreases within the brain and copper increases in the blood and the pool not bound to ceruloplasmin (non-Cp Cu, also known in the literature as "free" copper). The calculated non-Cp Cu (Walshe's) index has many limitations. A direct fluorescent method for non-Cp Cu detection has been developed and data are presented herein. The study included samples from 147 healthy subjects, 36 stable mild cognitive impairment (MCI) and 89 AD patients, who were tested for non-Cp Cu through the direct method, total serum copper, ceruloplasmin concentration and o-dianisidine ceruloplasmin activity. The indirect non-Cp Cu Walshe's index was also calculated. The direct method was linear (0.9-5.9 μM), precise (within-laboratory coefficient variation of 9.7% for low and 7.1% for high measurements), and had a good recovery. A reference interval (0-1.9 μM) was determined parametrically in 147 healthy controls (27-84 years old). The variation of non-Cp Cu was evaluated according to age and sex. Non-Cp Cu was 1.5 times higher in AD patients (regarding the upper value of the reference interval) than in healthy controls. Healthy, MCI and AD subjects were differentiated through the direct non-Cp Cu method [areas under the curve (AUC)=0.755]. Considering a 95% specificity and a 1.91 μmol/L cut-off, the sensitivity was 48.3% (confidence interval 95%: 38%-58%). The likelihood ratio (LR) was 9.94 for positive test results (LR+) and 0.54 for negative test result (LR-). The direct fluorescent test reliably and accurately measures non-Cp Cu, thereby determining the probability of having AD.

Seebeck Coefficient of Cation-Substituted Disulfides CuCr1-x Fe x S2 and Cu1-x Fe x CrS2

NASA Astrophysics Data System (ADS)

Korotaev, Evgeniy V.; Syrokvashin, Mikhail M.; Filatova, Irina Yu.; Pelmenev, Konstantin G.; Zvereva, Valentina V.; Peregudova, Natalya N.

2018-03-01

The effect of cation substitution on the Seebeck coefficient of CuCr1-x Fe x S2 (x = 0 to 0.30) and Cu1-x Fe x CrS2 (x = 0 to 0.03) in the temperature range of 100 K to 450 K has been investigated. Increasing iron concentration led to a metal-insulator transition which suppressed the thermoelectric power. However, for low iron concentration (x < 0.03), the Seebeck coefficient of CuCr1-x Fe x S2 and Cu1-x Fe x CrS2 exceeded the values for the undoped copper-chromium disulfide matrix CuCrS2 at temperature below 300 K.

The effect of iron and copper impurities on the wettability of sphalerite (110) surface.

PubMed

Simpson, Darren J; Bredow, Thomas; Chandra, Anand P; Cavallaro, Giuseppe P; Gerson, Andrea R

2011-07-15

The effect of impurities in the zinc sulfide mineral sphalerite on surface wettability has been investigated theoretically to shed light on previously reported conflicting results on sphalerite flotation. The effect of iron and copper impurities on the sphalerite (110) surface energy and on the water adsorption energy was calculated with the semi-empirical method modified symmetrically orthogonalized intermediate neglect of differential overlap (MSINDO) using the cyclic cluster model. The effect of impurities or dopants on surface energies is small but significant. The surface energy increases with increasing surface iron concentration while the opposite effect is reported for increasing copper concentration. The effect on adsorption energies is much more pronounced with water clearly preferring to adsorb on an iron site followed by a zinc site, and copper site least favorable. The theoretical results indicate that a sphalerite (110) surface containing iron is more hydrophilic than the undoped zinc sulfide surface. In agreement with the literature, the surface containing copper (either naturally or by activation) is more hydrophobic than the undoped surface. Copyright © 2011 Wiley Periodicals, Inc.

Comparative study on the passivation layers of copper sulphide minerals during bioleaching

NASA Astrophysics Data System (ADS)

Fu, Kai-bin; Lin, Hai; Mo, Xiao-lan; Wang, Han; Wen, Hong-wei; Wen, Zi-long

2012-10-01

The bioleaching of copper sulphide minerals was investigated by using A. ferrooxidans ATF6. The result shows the preferential order of the minerals bioleaching as djurleite>bornite>pyritic chalcopyrite>covellite>porphyry chalcopyrite. The residues were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It is indicated that jarosite may not be responsible for hindered dissolution. The elemental sulfur layer on the surface of pyritic chalcopyrite residues is cracked. The compact surface layer of porphyry chalcopyrite may strongly hinder copper extraction. X-ray photoelectron spectroscopy (XPS) further confirms that the passivation layers of covellite, pyritic chalcopyrite, and porphyry chalcopyrite are copper-depleted sulphide Cu4S11, S8, and copper-rich iron-deficient polysulphide Cu4Fe2S9, respectively. The ability of these passivation layers was found as Cu4Fe2S9>Cu4S11>S8>jarosite.

Phytoremediation of heavy metal copper (Cu2+) by sunflower (Helianthus annuus l.)

NASA Astrophysics Data System (ADS)

Mahardika, G.; Rinanti, A.; Fachrul, M. F.

2018-01-01

A study in microcosmic condition has been carried out to determine the effectiveness of Helianthus annuus as a hyperaccumulator plant for heavy metal, Copper (Cu2+), that exposed in the soil. Artificial pollutants containing Copper (Cu2+) 0, 60, 120, 180 ppm are exposed to uncontaminated soil. The 12-weeks old H. annuus seedling were grown in Cu2+ contaminated soil, with variations of absorption time 3, 6, and 9 weeks. Analysis of Cu2+ concentration on soil and H. annuus (root, stem, leaf) was analised by Atomic Absorbtion Spectrometry (AAS). H. annuus are capable for Cu2+ removal, and the highest removal of Cu2+ is 85.56%, the highest metal accumulation/bioconcentration factor (BCF) is 0.99 occurred at roots with 9 weeks of exposure time and the highest translocation factor (TF) is 0.71. This highest removal is five times better than absorption by stems and leaves. The results concluded, the use of H. annuus for phytoextraction of heavy metals Cu2+ in contaminated soil can be an alternative to the absorption of heavy metal Cu2+ with low concentration metals which is generally very difficult to do in physical-chemical removal.

Characterization of the interface interaction of cobalt on top of copper- and iron-phthalocyanine.

PubMed

Schmitt, Felix; Sauther, Jens; Lach, Stefan; Ziegler, Christiane

2011-05-01

The electronic structure of the interface between ferromagnetic cobalt and the organic semiconductors copper- (CuPc) and iron-phthalocyanine (FePc) was investigated by means of photoemission spectroscopy (UPS, IPES, and XPS). These metal-phthalocyanine (MePc) molecules have an open shell structure and are known to show promising properties for their use in organic spintronics. In spintronic devices, the interface between ferromagnetic electrode and the organic layer determines the spin injection properties and is hence important for the quality of, e.g., a possible spin-valve device. For this purpose, cobalt was deposited onto the MePcs, such as in devices with ferromagnetic top contacts. The reported investigations reveal a diffusion of cobalt into the organic layers and chemical reactions at the interface.

Studies of copper trafficking in a mouse model of Alzheimer's disease by positron emission tomography: comparison of 64Cu acetate and 64CuGTSM.

PubMed

Andreozzi, Erica M; Torres, Julia Baguña; Sunassee, Kavitha; Dunn, Joel; Walker-Samuel, Simon; Szanda, Istvan; Blower, Philip J

2017-11-15

Alzheimer's disease can involve brain copper dyshomeostasis. We aimed to determine the effect of AD-like pathology on 64 Cu trafficking in mice, using positron emission tomography (PET imaging), during 24 hours after intravenous administration of ionic 64 Cu (Cu(ii) acetate) and 64 Cu-GTSM (GTSMH 2 = glyoxalbis(thiosemicarbazone)). Copper trafficking was evaluated in 6-8-month-old and 13-15 month-old TASTPM transgenic and wild-type mice, by imaging 0-30 min and 24-25 h after intravenous administration of 64 Cu tracer. Regional 64 Cu distribution in brains was compared by ex vivo autoradiography to that of amyloid-β plaque. 64 Cu-acetate showed uptake in, and excretion through, liver and kidneys. There was minimal uptake in other tissues by 30 minutes, and little further change after 24 h. Radioactivity within brain was focussed in and around the ventricles and was significantly greater in younger mice. 64 CuGTSM was taken up in all tissues by 30 min, remaining high in brain but clearing substantially from other tissues by 24 h. Distribution in brain was not localised to specific regions. TASTPM mice showed no major changes in global or regional 64 Cu brain uptake compared to wildtype after administration of 64 Cu acetate (unlike 64 Cu-GTSM) but efflux of 64 Cu from brain by 24 h was slightly greater in 6-8 month-old TASTPM mice than in wildtype controls. Changes in copper trafficking associated with Alzheimer's-like pathology after administration of ionic 64 Cu are minor compared to those observed after administration of 64 Cu-GTSM. PET imaging with 64 Cu could help understand changes in brain copper dynamics in AD and underpin new clinical diagnostic imaging methods.

A novel recovery method of copper from waste printed circuit boards by supercritical methanol process: Preparation of ultrafine copper materials.

PubMed

Xiu, Fu-Rong; Weng, Huiwei; Qi, Yingying; Yu, Gending; Zhang, Zhigang; Zhang, Fu-Shen; Chen, Mengjun

2017-02-01

In this study, supercritical methanol (SCM) process was successfully used for the preparation of ultrafine copper materials from waste printed circuit boards (PCBs) after nitric acid pretreatment. Waste PCBs were pretreated twice in nitric acid. Sn and Pb were recovered by the first nitric acid pretreatment. The leach liquor with a high concentration of copper ions after the second nitric acid leaching was subjected to SCM process. The mixture of Cu and Cu 2 O with poor uniformity of particle size was formed due to the effect of ferric iron contained in the leach liquor of waste PCBs, while more uniform and spherical Cu particles with high monodispersity and smaller size could be prepared after the removal of Fe. The size of Cu particles increased obviously with the decline of SCM temperature, and particles became highly aggregated when the reaction temperature decreased to 300°C. The size of Cu particles decreased markedly with the decrease of initial concentration of copper ion in the leach liquor of waste PCBs. It is believed that the process developed in this study is simple and practical for the preparation of ultrafine copper materials from waste PCBs with the aim of recycling these waste resources as a high value-added product. Copyright © 2016 Elsevier Ltd. All rights reserved.

Origin of sulfur and crustal recycling of copper in polymetallic (Cu-Au-Co-Bi-U ± Ag) iron-oxide-dominated systems of the Great Bear Magmatic Zone, NWT, Canada

NASA Astrophysics Data System (ADS)

Acosta-Góngora, P.; Gleeson, S. A.; Samson, I. M.; Corriveau, L.; Ootes, L.; Jackson, S. E.; Taylor, B. E.; Girard, I.

2018-03-01

The Great Bear Magmatic Zone, in northwest Canada, contains numerous polymetallic mineral occurrences, prospects, and deposits of the iron oxide copper-gold deposit (IOCG) family. The mineralization is hosted by the Treasure Lake Group and igneous rocks of the Great Bear arc and was deposited concomitantly with the arc magmatism (ca. 1.88 to 1.87 Ga). In situ δ 34S ( n = 48) and δ 65Cu ( n = 79) analyses were carried out on ore-related sulfides from a number of these systems. The δ 34S values mainly vary between 0 and +5‰, consistent with derivation of sulfur from the mantle. Lower δ 34S values (-7.7 to +1.4‰) from the Sue-Dianne breccia may indicate SO2 disproportionation of a magmatic hydrothermal fluid. The δ 65Cu values vary between -1.2 and -0.3‰, and are lower than the igneous δ 65Cu range of values (0.0 ± 0.27‰). The S and Cu isotopic data are decoupled, which suggests that Cu (and possibly some S) was dissolved and remobilized from supracrustal rocks during early stages of alteration (e.g., sodic alteration) and then precipitated by lower temperature, more oxidizing fluids (e.g., Ca-Fe-K alteration). A limited fluid inclusion dataset and δ 13C and δ 18O values are also presented. The δ 18Ofluid values are consistent with a magmatic origin or a host-rock equilibrated meteoric water source, whereas the δ 13Cfluid values support a marine carbonate source. Combined, the S and Cu isotopic data indicate that while the emplacement of the Great Bear magmatic bodies may have driven fluid convection and may be the source of fluids and sulfur, metals such as Cu could have been recycled from crustal sources.

Thermal and Surface Evaluation on The Process of Forming a Cu2O/CuO Semiconductor Photocatalyst on a Thin Copper Plate

NASA Astrophysics Data System (ADS)

Zainul, R.; Oktavia, B.; Dewata, I.; Efendi, J.

2018-04-01

This research aims to investigate the process of forming a multi-scale copper oxide semiconductor (CuO/Cu2O) through a process of calcining a copper plate. The changes that occur during the formation of the oxide are thermally and surface evaluated. Evaluation using Differential Thermal Analysis (DTA) obtained by surface change of copper plate happened at temperature 380°C. Calcination of oxide formation was carried out at temperature 380°C for 1 hour. Surface evaluation process by using Scanning Electron Microscope (SEM) surface and cross-section, to determine diffusion of oxide formation on copper plate. The material composition is monitored by XRF and XRD to explain the process of structural and physical changes of the copper oxide plate formed during the heating process. The thickness of Cu plates used is 200-250 μm. SEM analysis results, the oxygen atom interruption region is in the range of 20-30 μm, and diffuses deeper during thermal oxidation process. The maximum diffusion depth of oxygen atoms reaches 129 μm.

Age-dependent Changes of Cerebral Copper Metabolism in Atp7b−/− Knockout Mouse Model of Wilson’s Disease by [64Cu]CuCl2-PET/CT

PubMed Central

Xie, Fang; Xi, Yin; Pascual, Juan M.; Muzik, Otto; Peng, Fangyu

2017-01-01

Copper is a nutritional metal required for brain development and function. Wilson’s disease (WD), or hepatolenticular degeneration, is an inherited human copper metabolism disorder caused by mutation of ATP7B gene. Many WD patients present with variable neurological and psychiatric symptoms, which may be related to neurodegeneration secondary to copper metabolism imbalance. The objective of this study is to explore feasibility and use of copper-64 chloride ([64C]CuCl2) as a tracer for noninvasive assessment of age-dependence changes of cerebral copper metabolism in WD using an Atp7b−/− knockout mouse model of WD and a positron emission tomography/computed tomography (PET/CT) scanner. Continuing from recent study of biodistribution and radiation dosimetry of [64C]CuCl2 in Atp7b−/− knockout mice, PET quantitative analysis revealed low 64Cu radioactivity in the brains of Atp7b−/− knockout mice at 7th week of age, compared with the 64Cu radioactivity in the brains of age and gender-matched wild type C57BL/6 mice, at 24 hour (h) post intravenous injection of [64C]CuCl2 as a tracer. Furthermore, age-dependent increase of 64Cu radioactivity was detected in the brains of Atp7b−/− knockout mice from 13th to 21th week of age, using the data derived from a longitudinal [64C]CuCl2-PET/CT study of Atp7b−/− knockout mice with orally administered [64Cu]CuCl2 as a tracer. The findings of this study support the use of [64Cu]CuCl2-PET/CT as a tool for noninvasive assessment of age-dependent changes of cerebral copper metabolism in WD patients presenting with variable neurological and psychiatric symptoms. PMID:28130615

Regulation of extracellular copper-binding proteins in copper-resistant and copper-sensitive mutants of Vibrio alginolyticus.

PubMed Central

Harwood, V J; Gordon, A S

1994-01-01

Extracellular proteins of wild-type Vibrio alginolyticus were compared with those of copper-resistant and copper-sensitive mutants. One copper-resistant mutant (Cu40B3) constitutively produced an extracellular protein with the same apparent molecular mass (21 kDa) and chromatographic behavior as copper-binding protein (CuBP), a copper-induced supernatant protein which has been implicated in copper detoxification in wild-type V. alginolyticus. Copper-sensitive V. alginolyticus mutants displayed a range of alterations in supernatant protein profiles. CuBP was not detected in supernatants of one copper-sensitive mutant after cultures had been stressed with 50 microM copper. Increased resistance to copper was not induced by preincubation with subinhibitory levels of copper in the wild type or in the copper-resistant mutant Cu40B3. Copper-resistant mutants maintained the ability to grow on copper-amended agar after 10 or more subcultures on nonselective agar, demonstrating the stability of the phenotype. A derivative of Cu40B3 with wild-type sensitivity to copper which no longer constitutively expressed CuBP was isolated. The simultaneous loss of both constitutive CuBP production and copper resistance in Cu40B3 indicates that constitutive CuBP production is necessary for copper resistance in this mutant. These data support the hypothesis that the extracellular, ca. 20-kDa protein(s) of V. alginolyticus is an important factor in survival and growth of the organism at elevated copper concentrations. The range of phenotypes observed in copper-resistant and copper-sensitive V. alginolyticus indicate that altered sensitivity to copper was mediated by a variety of physiological changes. Images PMID:8031076

Copper absorption from foods labelled intrinsically and extrinsically with Cu-65 stable isotope.

PubMed

Harvey, L J; Dainty, J R; Beattie, J H; Majsak-Newman, G; Wharf, S G; Reid, M D; Fairweather-Tait, S J

2005-03-01

To determine copper absorption from copper containing foods labelled either intrinsically or extrinsically with a highly enriched Cu-65 stable isotope label. A longitudinal cross-over study. The study was conducted at the Institute of Food Research, Human Nutrition Unit, Norwich, UK. Subjects were recruited locally via advertisements placed around the Norwich Research Park. A total of 10 volunteers (nine female, one male) took part in the study, but not all volunteers completed each of the test meals. A highly enriched Cu-65 stable isotope label was administered to volunteers in the form of a reference dose or in breakfast test meals consisting of red wine, soya beans, mushrooms or sunflower seeds. Faecal monitoring and mass spectrometry techniques were used to estimate the relative quantities of copper absorbed from the different test meals. True copper absorption from the reference dose (54%) was similar to extrinsically labelled red wine (49%) and intrinsically labelled sunflower seeds (52%), but significantly higher than extrinsically labelled mushrooms (35%), intrinsically (29%) and extrinsically (15%) labelled soya beans and extrinsically labelled sunflower seed (32%) test meals. The use of Cu-65 extrinsic labels in copper absorption studies requires validation according to the food being examined; intrinsic and extrinsic labelling produced significantly different results for sunflower seeds.

Interstitial copper defect induced reconstruction of a new ;CuO4; quadrilateral in CaCu3Ti4O12: A first-principles study

NASA Astrophysics Data System (ADS)

Xiao, Haibo; Xu, Linfang; Wang, Ruilong; Yang, Changping

2017-09-01

The geometric structure, electronic structure and formation energy of CaCu3Ti4O12 (CCTO) with interstitial copper atom have been studied using the density-functional method within the GGA approximation. Result of structural optimization shows that the interstitial Cu-atom (Cu7) prefers to occupy a special location which is symmetrical with an intrinsic copper atom (Cu13) deviated from the normal site. The mulliken analysis indicates the loss of electrons from interstitial atom (Cu7) and Cu13 are only half more of the losing in other copper atom, which reveals a characteristics of covalent bonding between Cu7/Cu13 and surrounding oxygen atoms respectively. Meanwhile, it is found from electron density difference (EDD) and orbital analysis that the introduction of interstitial Cu atom causes prominent structural reconstruction of a new ;CuO4; quadrilateral. Moreover, the new ;CuO4; planar leads to a corresponding electronic reconstruction in the hybridization between Cu7/Cu13 3d and O 2p at the vicinity of fermi surface, for which a new conductive filament channel comes into being. Besides, the formation energies of the interstitial defects in various charge states are corrected with the value of 2.18, -4.17 and -9.46 eV for charge of 0, 1+ and 2+, respectively.

Impact of wine production on the fractionation of copper and iron in Chardonnay wine: Implications for oxygen consumption.

PubMed

Rousseva, Michaela; Kontoudakis, Nikolaos; Schmidtke, Leigh M; Scollary, Geoffrey R; Clark, Andrew C

2016-07-15

Copper and iron in wine can influence oxidative, reductive and colloidal stability. The current study utilises a solid phase extraction technique to fractionate these metals into hydrophobic, cationic and residual forms, with quantification by ICP-OES. The impact of aspects of wine production on the metal fractions was examined, along with the relationship between metal fractions and oxygen decay rates. Addition of copper and iron to juice, followed by fermentation, favoured an increase in all of their respective metal fractions in the wine, with the largest increase observed for the cationic form of iron. Bentonite fining of the protein-containing wines led to a significant reduction in the cationic fraction of copper and an increase in the cationic form of iron. Total copper correlated more closely with oxygen consumption in the wine compared to total iron, and the residual and cationic forms of copper provided the largest contribution to this impact. Copyright © 2016 Elsevier Ltd. All rights reserved.

The effect of silver (Ag) addition to mechanical and electrical properties of copper alloy (Cu) casting product

NASA Astrophysics Data System (ADS)

Felicia, Dian M.; Rochiem, R.; Laia, Standley M.

2018-04-01

Copper have good mechanical properties and good electrical conductivities. Therefore, copper usually used as electrical components. Silver have better electrical conductivities than copper. Female contact resistor is one of the electrical component used in circuit breaker. This study aims to analyze the effect of silver addition to hardness, strength, and electric conductivity properties of copper alloy. This study uses variation of 0; 0.035; 0.07; 0.1 wt. % Ag (silver) addition to determine the effect on mechanical properties and electrical properties of copper alloy through sand casting process. Modelling of thermal analysis and structural analysis was calculated to find the best design for the sand casting experiments. The result of Cu-Ag alloy as cast will be characterized by OES test, metallography test, Brinell hardness test, tensile test, and LCR meter test. The result of this study showed that the addition of silver increase mechanical properties of Cu-Ag. The maximum hardness value of this alloy is 83.1 HRB which is Cu-0.01 Ag and the lowest is 52.26 HRB which is pure Cu. The maximum strength value is 153.2 MPa which is Cu-0.07 Ag and the lowest is 94.6 MPa which is pure Cu. Silver addition decrease electrical properties of this alloy. The highest electric conductivity is 438.98 S/m which is pure Cu and the lowest is 52.61 S.m which is Cu-0.1 Ag.

Fractionation of fulvic acid by iron and aluminum oxides: influence on copper toxicity to Ceriodaphnia dubia

USGS Publications Warehouse

Smith, Kathleen S.; Ranville, James F.; Lesher, Emily K.; Diedrich, Daniel J.; McKnight, Diane M.; Sofield, Ruth M.

2014-01-01

This study examines the effect on aquatic copper toxicity of the chemical fractionation of fulvic acid (FA) that results from its association with iron and aluminum oxyhydroxide precipitates. Fractionated and unfractionated FAs obtained from streamwater and suspended sediment were utilized in acute Cu toxicity tests on ,i>Ceriodaphnia dubia. Toxicity test results with equal FA concentrations (6 mg FA/L) show that the fractionated dissolved FA was 3 times less effective at reducing Cu toxicity (EC50 13 ± 0.6 μg Cu/L) than were the unfractionated dissolved FAs (EC50 39 ± 0.4 and 41 ± 1.2 μg Cu/L). The fractionation is a consequence of preferential sorption of molecules having strong metal-binding (more aromatic) moieties to precipitating Fe- and Al-rich oxyhydroxides, causing the remaining dissolved FA to be depleted in these functional groups. As a result, there is more bioavailable dissolved Cu in the water and hence greater potential for Cu toxicity to aquatic organisms. In predicting Cu toxicity, biotic ligand models (BLMs) take into account dissolved organic carbon (DOC) concentration; however, unless DOC characteristics are accounted for, model predictions can underestimate acute Cu toxicity for water containing fractionated dissolved FA. This may have implications for water-quality criteria in systems containing Fe- and Al-rich sediment, and in mined and mineralized areas in particular. Optical measurements, such as specific ultraviolet absorbance at 254 nm (SUVA254), show promise for use as spectral indicators of DOC chemical fractionation and inferred increased Cu toxicity.

Distribution of copper, iron, and zinc in biological samples (scalp hair, serum, blood, and urine) of Pakistani viral hepatitis (A-E) patients and controls.

PubMed

Kolachi, Nida Fatima; Kazi, Tasneem Gul; Afridi, Hassan Imran; Kazi, Naveed; Kandhro, Ghulam Abbas; Shah, Abdul Qadir; Baig, Jameel Ahmed; Wadhwa, Sham Kumar; Khan, Sumaira; Shah, Faheem; Jamali, Mohammad Khan; Arain, Mohammad Balal

2011-10-01

The aim of the present study was to compare the level of copper (Cu), iron (Fe) and zinc (Zn) in biological samples (serum, blood, urine, and scalp hair) of patients suffering from different viral hepatitis (A, B, C, D, and E; n = 521) of both gender age ranged 31-45 years. For comparative study, 255 age-matched control subjects, of both genders residing in the same city were selected as referents. The elements in the biological samples were analyzed by flame atomic absorption spectrophotometry, prior to microwave-assisted acid digestion. The validity and accuracy of the methodology was checked by using certified reference materials (CRMs) and with those values obtained by conventional wet acid digestion method on same CRMs. The results of this study showed that the mean values of Cu and Fe were higher in blood, sera, and scalp hair samples of hepatitis patients, while Zn level was found to be lower than age-matched control subjects. The urinary levels of these elements were found to be higher in the hepatitis patients than in the age-matched healthy controls (p < 0.05). These results are consistent with literature-reported data, confirming that the deficiency of zinc and hepatic iron and copper overload can directly cause lipid peroxidation and eventually hepatic damage.

Biochemical Evolution of Iron and Copper Proteins, Substances Vital to Life

ERIC Educational Resources Information Center

Frieden, Earl

1974-01-01

Summarizes studies in the area of biochemical evolution of iron, copper, and heme proteins to provide an historical outline. Included are lists of major kinds of proteins and enzymes and charts illustrating electron flow in a cytochrome electron transport system and interconversion of jerrous to ferric ion in iron metabolism. (CC)

Fetal and neonatal iron deficiency but not copper deficiency increases vascular complexity in the developing rat brain

PubMed Central

Bastian, Thomas W.; Santarriaga, Stephanie; Nguyen, Thu An; Prohaska, Joseph R.; Georgieff, Michael K.; Anderson, Grant W.

2015-01-01

Objectives Anemia caused by nutritional deficiencies, such as iron and copper deficiencies, is a global health problem. Iron and copper deficiencies have their most profound effect on the developing fetus/infant, leading to brain development deficits and poor cognitive outcomes. Tissue iron depletion or chronic anemia can induce cellular hypoxic signaling. In mice, chronic hypoxia induces a compensatory increase in brain blood vessel outgrowth. We hypothesized that developmental anemia, due to iron or copper deficiencies, induces angiogenesis/vasculogenesis in the neonatal brain. Methods To test our hypothesis, three independent experiments were performed where pregnant rats were fed iron- or copper-deficient diets from gestational day 2 through mid-lactation. Effects on the neonatal brain vasculature were determined using qPCR to assess mRNA levels of angiogenesis/vasculogenesis-associated genes and GLUT1 immunohistochemistry (IHC) to assess brain blood vessel density and complexity. Results Iron deficiency, but not copper deficiency, increased mRNA expression of brain endothelial cell- and angiogenesis/vasculogenesis-associated genes (i.e. Glut1, Vwf, Vegfa, Ang2, Cxcl12, and Flk1) in the neonatal brain, suggesting increased cerebrovascular density. Iron deficiency also increased hippocampal and cerebral cortical blood vessel branching by 62% and 78%, respectively. Discussion This study demonstrates increased blood vessel complexity in the neonatal iron-deficient brain, which is likely due to elevated angiogenic/vasculogenic signaling. At least initially, this is probably an adaptive response to maintain metabolic substrate homeostasis in the developing iron-deficient brain. However, this may also contribute to long-term neurodevelopmental deficits. PMID:26177275

Arabidopsis Copper Transport Protein COPT2 Participates in the Cross Talk between Iron Deficiency Responses and Low-Phosphate Signaling1[C][W

PubMed Central

Perea-García, Ana; Garcia-Molina, Antoni; Andrés-Colás, Nuria; Vera-Sirera, Francisco; Pérez-Amador, Miguel A.; Puig, Sergi; Peñarrubia, Lola

2013-01-01

Copper and iron are essential micronutrients for most living organisms because they participate as cofactors in biological processes, including respiration, photosynthesis, and oxidative stress protection. In many eukaryotic organisms, including yeast (Saccharomyces cerevisiae) and mammals, copper and iron homeostases are highly interconnected; yet, such interdependence is not well established in higher plants. Here, we propose that COPT2, a high-affinity copper transport protein, functions under copper and iron deficiencies in Arabidopsis (Arabidopsis thaliana). COPT2 is a plasma membrane protein that functions in copper acquisition and distribution. Characterization of the COPT2 expression pattern indicates a synergic response to copper and iron limitation in roots. We characterized a knockout of COPT2, copt2-1, that leads to increased resistance to simultaneous copper and iron deficiencies, measured as reduced leaf chlorosis and improved maintenance of the photosynthetic apparatus. We propose that COPT2 could play a dual role under iron deficiency. First, COPT2 participates in the attenuation of copper deficiency responses driven by iron limitation, possibly to minimize further iron consumption. Second, global expression analyses of copt2-1 versus wild-type Arabidopsis plants indicate that low-phosphate responses increase in the mutant. These results open up new biotechnological approaches to fight iron deficiency in crops. PMID:23487432

Copper, iron, and selenium dietary deficiencies negatively impact skeletal integrity: A review.

PubMed

Medeiros, Denis M

2016-06-01

Nutrients have been known to have a significant role in maintaining the health of the skeleton, both bone and cartilage. The nutrients that have received the majority of the attention are Vitamin D and calcium. However, limited attention has been directed toward three trace elements that may have mechanistic impact upon the skeletal tissues and could compromise skeletal health resulting from inadequate intakes of copper, iron, and selenium. The role of copper and selenium has been known, but the role of iron has only received recent attention. Copper deficiency is thought to impact bone health by a decrease in lysyl oxidase, a copper-containing enzyme, which facilitates collagen fibril crosslinking. Iron deficiency impact upon bone has only recently been discovered but the exact mechanism on how the deficient states enhance bone pathology is speculative. Selenium deficiency has an impact on cartilage thereby having an indirect impact on bone. However, several studies suggest that a mycotoxin when consumed by humans is the culprit in some cartilage disorders and the presence of selenium could attenuate the pathology. This review summarizes the current knowledge base with respect to skeletal integrity when each of these three trace elements are inadequate in diets of both animals and humans. © 2016 by the Society for Experimental Biology and Medicine.

Accumulation and depletion of liver copper stores in dairy cows challenged with a Cu-deficient diet and oral and injectable forms of Cu supplementation.

PubMed

Balemi, S C; Grace, N D; West, D M; Smith, S L; Knowles, S O

2010-06-01

To quantify the capacity of the liver to respond to a Cu-deficient diet and various forms of Cu supplementation in dairy cows with high Cu status. Sixty non-pregnant, non lactating mixed-age Friesian dairy cows were fed baled silage for 116 days, containing 5.8 mg Cu/kg dry matter (DM), that provided an inadequate Cu intake. They were either unsupplemented (Control); or treated thrice weekly orally with solutions containing the equivalent of 150 mg Cu/day as copper sulphate pentahydrate (CS), copper amino chelate (CAC), or copper glycinate (CG); 16 g Cu as CuO wire particles, administered in an intra-ruminal bolus on Day 0; or 100 mg Cu as calcium copper edetate, administered by S/C injection on Days 0 and 58. On Days -5, 14, 28, 58, 86 and 116, liver biopsies and blood samples were obtained for determination of Cu. Mean initial concentrations of Cu in liver for all groups was 827 (SE 42) micromol/kg fresh tissue. In control cows, this decreased to 552 micromol/kg on Day 116, and averaged 670 micromol/kg over the length of the trial. Oral forms of Cu supplementation increased overall mean concentrations in liver to 960 (SE 79), 1,050 (SE 81) and 1,100 (SE 84) micromol/kg for CS, CAC and CG, respectively, but there was no difference between form of supplement. Mean concentrations were significantly increased by bolus treatment, but not by injection. Concentrations of Cu in serum in all groups decreased from 12.1 (SE 0.3) to 10.4 (SE 0.6) micromol/L by Day 116, with no differences due to treatments. The initial concentration of Cu in liver significantly affected the rate of accumulation of Cu among cows supplemented orally. In cows with an initial concentration <1,100 micromol/kg, the average increase was 4.1 micromol/kg fresh tissue/day, whereas rates were variable, even negative, when initial concentrations were >1,100 micromol/kg. Release of Cu over 116 days in cows given the bolus was calculated to be equivalent to an oral intake of CS of 106 mg Cu/day. In dairy

Rapid recovery of dilute copper from a simulated Cu-SDS solution with low-cost steel wool cathode reactor.

PubMed

Chang, Shih-Hsien; Wang, Kai-Sung; Hu, Pei-I; Lui, I-Chun

2009-04-30

Copper-surfactant wastewaters are often encountered in electroplating, printed circuit boards manufacturing, and metal finishing industries, as well as in retentates from micellar-enhanced ultrafiltration process. A low-cost three-dimensional steel wool cathode reactor was evaluated for electrolytic recovery of Cu ion from dilute copper solution (0.2mM) in the presence of sodium dodecyl sulfate (SDS), octylphenol poly (ethyleneglycol) 9.5 ether (TX), nonylphenol poly (oxyethylene) 9 ether (NP9) and polyoxyethylene (20) sorbitan monooleate (TW) and also mixed surfactants (anionic/nonionic). The reactor showed excellent copper recovery ability in comparison to a parallel-plate reactor. The reactor rapidly recovered copper with a reasonable current efficiency. 93% of copper was recovered at current density of 1 A m(-2) and pH 4 in the presence of 8.5mM SDS. Initial solution pH, cathodic current density, solution mixing condition, SDS concentration, and initial copper concentrations significantly influenced copper recovery. The copper recovery rate increased with an increase in aqueous SDS concentrations between 5 and 8.5mM. The influences of nonionic surfactants on Cu recovery from SDS-Cu solution depended not only on the type of surfactants used, but also on applied concentrations. From the copper recovery perspective, TX at 0.1mM or NP should be selected rather than TW, because they did not inhibit copper recovery from SDS-Cu solution.

A proof for substitution of endogenous iron (II) in lipoxygenase by exogenous Cu2+.

PubMed

Cai, Yan; Xu, Hong; Xia, Yongmei; Su, Yafen; Fang, Yun

2010-10-01

Soybean lipoxygenase (LOX) contains endogenous iron (II) at the active site, which is important for the enzyme activity. The activity of LOX can be accelerated by some exogenous metal ions including Cu2+. However, the mechanism of the activity improvement caused by exogenous metal ions remains unclear, not only for LOX but for most other metalloenzymes. Meanwhile, the possibility that exogenous metal ions can displace endogenous iron (II) is still in discussion for a lack of a direct and quantitative proof. In this paper, a quantitative proof of replacing iron (II) inside LOX by exogenous Cu2+ was provided, simply using UV-Vis spectrometry with two indicators p-carboxylantipyrylazo and 9-(4-carboxyphenyl)-2,3,7-trihydroxyl-6-fluorine. A 0.56 microM free iron (II) was observed in the bulk solution after incubating 9.45 microM Cu2+ with 16.10 microM LOX at 20 degrees C for 5 min, which is in coincidence with the decrement of Cu2+ in the bulk solution (0.53 microM), implying that iron (II) was replaced by Cu2+.

Iron Recovery from Copper Slag Through Oxidation-Reduction Magnetic Concentration at Intermediate Temperature

NASA Astrophysics Data System (ADS)

Wu, Zhiwen; Chen, Chen; Feng, Yahui; Hong, Xin

Large amounts of copper slag containing about 40 wt% iron is generated during the process of producing copper. Recovery of iron from the copper slag is very essential not only for recycling the valuable metals and mineral resources but also for protecting the environment. The purpose of this study was to investigate the possibility of separating fayalite by oxidation-reduction process into Magnetite and silicate phases in intermediate temperature condition. Experimental results show that when the oxidation reaction at 1000°C for 120min and the oxygen flow is 0.1L/min, most fayalite decompose to hematite, less part of magnetite and silica. And then, the mixture of carbon and oxidation product is pressed into blocks and reduced to magnetite and silica at 900°C for 90min. A magnetic product containing about 57.9wt% iron was obtained from the magnetic separation under a magnetic field strength of 100 mT.

Sulfate radical degradation of acetaminophen by novel iron-copper bimetallic oxidation catalyzed by persulfate: Mechanism and degradation pathways

NASA Astrophysics Data System (ADS)

Zhang, Yuanchun; Zhang, Qian; Hong, Junming

2017-11-01

A novel iron coupled copper oxidate (Fe2O3@Cu2O) catalyst was synthesized to activate persulfate (PS) for acetaminophen (APAP) degradation. The catalysts were characterized via field-emission scanning electron microscopy and energy-dispersive X-ray spectrometry. The effects of the catalyst, PS concentration, catalyst dosage, initial pH, dissolved oxygen were analyzed for treatment optimization. Results indicated that Fe2O3@Cu2O achieved higher efficiency in APAP degradation than Fe2O3/PS and Cu2O/PS systems. The optimal removal efficiency of APAP (90%) was achieved within 40 min with 0.6 g/L PS and 0.3 g/L catalyst. To clarify the mechanism for APAP degradation, intermediates were analyzed with gas chromatography-mass spectrometry. Three possible degradation pathways were identified. During reaction, Cu(I) was found to react with Fe(III) to generate Fe(II), which is the most active phase for PS activation. Through the use of methanol and tert-butyl alcohol (TBA) as radical trappers, SO4rad - was identified as the main radical species that is generated during oxidation.

Combined copper/zinc attachment to prion protein

NASA Astrophysics Data System (ADS)

Hodak, Miroslav; Bernholc, Jerry

2013-03-01

Misfolding of prion protein (PrP) is responsible for diseases such as ``mad-cow disease'' in cattle and Creutzfeldt-Jacob in humans. Extensive experimental investigation has established that this protein strongly interacts with copper ions, and this ability has been linked to its still unknown function. Attachment of other metal ions (zinc, iron, manganese) have been demonstrated as well, but none of them could outcompete copper. Recent finding, however, indicates that at intermediate concentrations both copper and zinc ions can attach to the PrP at the octarepeat region, which contains high affinity metal binding sites. Based on this evidence, we have performed density functional theory simulations to investigate the combined Cu/Zn attachment. We consider all previously reported binding modes of copper at the octarepeat region and examine a possibility simultaneous Cu/Zn attachment. We find that this can indeed occur for only one of the known binding sites, when copper changes its coordination mode to allow for attachment of zinc ion. The implications of the simultaneous attachment on neural function remain to be explored.

Synthesis and characterization of a multifunctional inorganic-organic hybrid mixed-valence copper(I/II) coordination polymer: {[CuCN][Cu(isonic)2]}n

NASA Astrophysics Data System (ADS)

Liu, Dong-Sheng; Chen, Wen-Tong; Ye, Guang-Ming; Zhang, Jing; Sui, Yan

2017-12-01

A new multifunctional mixed-valence copper(I/II) coordination polymer, {[CuCN][Cu(isonic)2]}n(1) (Hisonic = isonicotinic acid), was synthesized by treating isonicotinic acid and 5-amino-tetrazolate (Hatz = 5-amino-tetrazolate) with copper(II) salts under hydrothermal conditions, and characterized by elemental analysis, infrared spectroscopy, and single crystal X-ray diffraction, respectively. The X-ray diffraction analysis reveals that compound exhibit noncentrosymmetric polar packing arrangement. It is three-dimensional (3D) framework with (3,5)-connected 'seh-3' topological network constructed from metal organic framework {[Cu(isonic)2]}n and the inorganic linear chain{Cu(CN)}n subunits. A remarkable feature of 1 is the rhombic open channels that are occupied by a linear chain of {Cu(CN)}n. Impressively compound 1 displays not only a second harmonic generation (SHG) response, but also a ferroelectric behavior and magnetic properties.

Ultrasonic recovery of copper and iron through the simultaneous utilization of Printed Circuit Boards (PCB) spent acid etching solution and PCB waste sludge.

PubMed

Huang, Zhiyuan; Xie, Fengchun; Ma, Yang

2011-01-15

A method was developed to recover the copper and iron from Printed Circuit Boards (PCB) manufacturing generated spent acid etching solution and waste sludge with ultrasonic energy at laboratory scale. It demonstrated that copper-containing PCB spent etching solution could be utilized as a leaching solution to leach copper from copper contained PCB waste sludge. It also indicated that lime could be used as an alkaline precipitating agent in this method to precipitate iron from the mixture of acidic PCB spent etching solution and waste sludge. This method provided an effective technique for the recovery of copper and iron through simultaneous use of PCB spent acid solution and waste sludge. The leaching rates of copper and iron enhanced with ultrasound energy were reached at 93.76% and 2.07% respectively and effectively separated copper from iron. Followed by applying lime to precipitate copper from the mixture of leachate and rinsing water produced by the copper and iron separation, about 99.99% and 1.29% of soluble copper and calcium were settled as the solids respectively. Furthermore the settled copper could be made as commercial rate copper. The process performance parameters studied were pH, ultrasonic power, and temperature. This method provided a simple and reliable technique to recover copper and iron from waste streams generated by PCB manufacturing, and would significantly reduce the cost of chemicals used in the recovery. Copyright © 2010 Elsevier B.V. All rights reserved.

Dysregulation of iron and copper homeostasis in nonalcoholic fatty liver

PubMed Central

Aigner, Elmar; Weiss, Günter; Datz, Christian

2015-01-01

Elevated iron stores as indicated by hyperferritinemia with normal or mildly elevated transferrin saturation and mostly mild hepatic iron deposition are a characteristic finding in subjects with non-alcoholic fatty liver disease (NAFLD). Excess iron is observed in approximately one third of NAFLD patients and is commonly referred to as the “dysmetabolic iron overload syndrome”. Clinical evidence suggests that elevated body iron stores aggravate the clinical course of NAFLD with regard to liver-related and extrahepatic disease complications which relates to the fact that excess iron catalyses the formation of toxic hydroxyl-radicals subsequently resulting in cellular damage. Iron removal improves insulin sensitivity, delays the onset of type 2 diabetes mellitus, improves pathologic liver function tests and likewise ameliorates NAFLD histology. Several mechanisms contribute to pathologic iron accumulation in NAFLD. These include impaired iron export from hepatocytes and mesenchymal Kupffer cells as a consequence of imbalances in the concentrations of iron regulatory factors, such as hepcidin, cytokines, copper or other dietary factors. This review summarizes the knowledge about iron homeostasis in NAFLD and the rationale for its therapeutic implications. PMID:25729473

Cu,Zn-superoxide dismutase is lower and copper chaperone CCS is higher in erythrocytes of copper-deficient rats and mice.

PubMed

West, Elizabeth C; Prohaska, Joseph R

2004-09-01

Discovery of a sensitive blood biochemical marker of copper status would be valuable for assessing marginal copper intakes. Rodent models were used to investigate whether erythrocyte concentrations of copper,zinc-superoxide dismutase (SOD), and the copper metallochaperone for SOD (CCS) were sensitive to dietary copper changes. Several models of copper deficiency were studied in postweanling male Holtzman rats, male Swiss Webster mice offspring, and both rat and mouse dams. Treatment resulted in variable but significantly altered copper status as evaluated by the presence of anemia, and lower liver copper and higher liver iron concentrations in copper-deficient compared with copper-adequate animals. Associated with this copper deficiency were consistent reductions in immunoreactive SOD and robust enhancements in CCS. In most cases, the ratio of CCS:SOD was several-fold higher in red blood cell extracts from copper-deficient compared with copper-adequate rodents. Determination of red cell CCS:SOD may be useful for assessing copper status of humans.

78 FR 65573 - Migratory Bird Hunting; Application for Approval of Copper-Clad Iron Shot and Fluoropolymer Shot...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-01

... supported approval of the shot and the coatings, and one contained no useful information. Therefore, as... Hunting; Application for Approval of Copper-Clad Iron Shot and Fluoropolymer Shot Coatings as Nontoxic for... environmental assessments. SUMMARY: We, the U.S. Fish and Wildlife Service, approve copper-clad iron shot and...

Hemoglobin and Myoglobin as Reducing Agents in Biological Systems. Redox Reactions of Globins with Copper and Iron Salts and Complexes.

PubMed

Postnikova, G B; Shekhovtsova, E A

2016-12-01

In addition to reversible O2 binding, respiratory proteins of the globin family, hemoglobin (Hb) and myoglobin (Mb), participate in redox reactions with various metal complexes, including biologically significant ones, such as those of copper and iron. HbO 2 and MbO 2 are present in cells in large amounts and, as redox agents, can contribute to maintaining cell redox state and resisting oxidative stress. Divalent copper complexes with high redox potentials (E 0 , 200-600 mV) and high stability constants, such as [Cu(phen) 2 ] 2+ , [Cu(dmphen) 2 ] 2+ , and CuDTA oxidize ferrous heme proteins by the simple outer-sphere electron transfer mechanism through overlapping π-orbitals of the heme and the copper complex. Weaker oxidants, such as Cu2+, CuEDTA, CuNTA, CuCit, CuATP, and CuHis (E 0 ≤ 100-150 mV) react with HbO 2 and MbO 2 through preliminary binding to the protein with substitution of the metal ligands with protein groups and subsequent intramolecular electron transfer in the complex (the site-specific outer-sphere electron transfer mechanism). Oxidation of HbO 2 and MbO 2 by potassium ferricyanide and Fe(3) complexes with NTA, EDTA, CDTA, ATP, 2,3-DPG, citrate, and pyrophosphate PP i proceeds mainly through the simple outer-sphere electron transfer mechanism via the exposed heme edge. According to Marcus theory, the rate of this reaction correlates with the difference in redox potentials of the reagents and their self-exchange rates. For charged reagents, the reaction may be preceded by their nonspecific binding to the protein due to electrostatic interactions. The reactions of LbO 2 with carboxylate Fe complexes, unlike its reactions with ferricyanide, occur via the site-specific outer-sphere electron transfer mechanism, even though the same reagents oxidize structurally similar MbO 2 and cytochrome b 5 via the simple outer-sphere electron transfer mechanism. Of particular biological interest is HbO 2 and MbO 2 transformation into met-forms in the presence

77 FR 59158 - Migratory Bird Hunting; Application for Approval of Copper-Clad Iron Shot and Fluoropolymer Shot...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-26

... June 20, 2012 (77 FR 36980), and one for the fluoropolymer shot coatings on July 6, 2012 (77 FR 39983... Bird Hunting; Application for Approval of Copper-Clad Iron Shot and Fluoropolymer Shot Coatings as... approve copper-clad iron shot and fluoropolymer coatings for hunting waterfowl and coots. We published a...

Effects of copper-precursors on the catalytic activity of Cu/graphene catalysts for the selective catalytic oxidation of ammonia

NASA Astrophysics Data System (ADS)

Li, Jingying; Tang, Xiaolong; Yi, Honghong; Yu, Qingjun; Gao, Fengyu; Zhang, Runcao; Li, Chenlu; Chu, Chao

2017-08-01

Different copper-precursors were used to prepare Cu/graphene catalysts by an impregnation method. XRD, Raman spectra, TEM, BET, XPS, H2-TPR, NH3-TPD, DRIFTS and catalytic activity test were used to characterize and study the effect of precursors on the catalytic activity of Cu/graphene catalysts for NH3-SCO reaction. The large specific surface area of Cu/graphene catalysts and high dispersion of the metal particles on the graphene caused the well catalytic activity of NH3-SCO reaction. Compared to Cu/GE(AC), Cu/GE(N) showed better catalytic performance, and the complete NH3 removal efficiency was obtained at 250 °C with N2 selectivity of 85%. The copper-precursors had influence on the distribution of surface Cu species and further affected the catalytic activity of Cu/GE catalysts. The more amount of surface Cu species and highly dispersed CuO particles on the graphene surface formed by using copper nitrate as precursor could significantly improve the reducibility of catalysts and enhance NH3 adsorption, thereby improving the catalytic activity of Cu/graphene catalyst.

Haemolysis and Perturbations in the Systemic Iron Metabolism of Suckling, Copper-Deficient Mosaic Mutant Mice – An Animal Model of Menkes Disease

PubMed Central

Lenartowicz, Małgorzata; Starzyński, Rafał R.; Krzeptowski, Wojciech; Grzmil, Paweł; Bednarz, Aleksandra; Ogórek, Mateusz; Pierzchała, Olga; Staroń, Robert; Gajowiak, Anna; Lipiński, Paweł

2014-01-01

The biological interaction between copper and iron is best exemplified by the decreased activity of multicopper ferroxidases under conditions of copper deficiency that limits the availability of iron for erythropoiesis. However, little is known about how copper deficiency affects iron homeostasis through alteration of the activity of other copper-containing proteins, not directly connected with iron metabolism, such as superoxide dismutase 1 (SOD1). This antioxidant enzyme scavenges the superoxide anion, a reactive oxygen species contributing to the toxicity of iron via the Fenton reaction. Here, we analyzed changes in the systemic iron metabolism using an animal model of Menkes disease: copper-deficient mosaic mutant mice with dysfunction of the ATP7A copper transporter. We found that the erythrocytes of these mutants are copper-deficient, display decreased SOD1 activity/expression and have cell membrane abnormalities. In consequence, the mosaic mice show evidence of haemolysis accompanied by haptoglobin-dependent elimination of haemoglobin (Hb) from the circulation, as well as the induction of haem oxygenase 1 (HO1) in the liver and kidney. Moreover, the hepcidin-ferroportin regulatory axis is strongly affected in mosaic mice. These findings indicate that haemolysis is an additional pathogenic factor in a mouse model of Menkes diseases and provides evidence of a new indirect connection between copper deficiency and iron metabolism. PMID:25247420

Iron-[S,S']-EDDS (FeEDDS) Chelate as an Iron Source for Horticultural Crop Production: Marigold Growth and Nutrition, Spectral Properties, and Photodegradation

USDA-ARS?s Scientific Manuscript database

Aminopolycarboxylic acid (APCA) complexones, commonly referred to as ligands or chelating agents, like ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) are commonly used in soluble fertilizers to supply copper (Cu), iron (Fe), manganese (Mn), and/or zinc (Zn) to p...

Association of Maternal Diet With Zinc, Copper, and Iron Concentrations in Transitional Human Milk Produced by Korean Mothers

PubMed Central

Kim, Ji-Myung; Lee, Ji-Eun; Cho, Mi Sook; Kang, Bong Soo; Choi, Hyeon

2016-01-01

The aims of this study were to evaluate zinc, copper, and iron concentrations in the transitory milk of Korean lactating mothers and to investigate the relationship between these concentrations and maternal diet. Human milk samples were collected between 5 and 15 days postpartum from 96 healthy, lactating mothers in postpartum care centers in Seoul, Korea. Dietary intake during lactation was determined based on a 3-day dietary record. The mean zinc, copper, and iron concentrations in the human milk samples collected were 3.88 ± 1.74 mg/L, 0.69 ± 0.25 mg/L, and 5.85 ± 8.53 mg/L, respectively. The mothers who consumed alcoholic beverages during pregnancy had tended to have lower concentrations of zinc and copper, as well as significantly lower concentrations of iron, in their milk (p < 0.047). In contrast, the mothers who took daily supplements had much higher iron concentrations in their milk (p = 0.002). Dietary intakes of zinc, copper, and iron during lactation did not affect the concentrations of zinc, copper, and iron in the milk samples analyzed. Intakes of vitamin C, selenium, and iodine were associated with the concentration of copper in the milk samples analyzed, and consumption of food categorized as 'meat and meat products' was positively associated with the concentration of zinc. Consumption of rice was the top contributor to the concentrations of all three minerals. In conclusion, associations between maternal diet and nutrient concentrations in transitory human milk can provide useful information, particularly in regard to infant growth. PMID:26839873

Change of Cu+ species and synergistic effect of copper and cerium during reduction-oxidation treatment for preferential CO oxidation

NASA Astrophysics Data System (ADS)

Zhang, Hao; Zhao, Xiaozhou; Wang, Shuang; Zeng, Shanghong; Su, Haiquan

2018-05-01

The CuO-CeO2@SiO2 catalyst with flower-sphere morphology was prepared by the impregnation method and then experienced the reduction-oxidation treatment at different temperatures. The multi-technique characterization shows that the reduction-oxidation treatment can remodel CuO, improve textural and surface properties and change Cu+ content and synergistic effect of copper and cerium. The importance of this work lies in the fact that the decrease of Cu+ content and synergistic effect of copper and cerium that occurs in the reduction-oxidation process results in the decrease of catalytic activity over the CuO-CeO2@SiO2 catalyst for preferential CO oxidation. The process of reaction in rich-hydrogen streams is equivalent to a reduction procedure which decreases Cu+ content and synergistic effect of copper and cerium.

Construction of leaf-like CuO-Cu2O nanocomposites on copper foam for high-performance supercapacitors.

PubMed

He, Dong; Wang, Guanda; Liu, Guolong; Suo, Hui; Zhao, Chun

2017-03-07

Leaf-like CuO-Cu 2 O nanosheets have been prepared on copper foam by a one-step simple anodization method, which can be used as an advanced binder-free supercapacitor electrode. The performance of the CuO-Cu 2 O/Cu foam electrode was optimized through controlling and restraining the current density and reaction time. The prepared electrode exhibits a very high specific capacitance (1.954 F cm -2 at a scan rate of 2 mV s -1 ), excellent durability (120% retention after 5000 cycles), remarkable rate capability (91.8% retention upon increasing the current density by 10 times) and good coulombic efficiency (78.2% at a current density of 2 mA cm -2 ). The facile and cost-effective fabrication process is also suitable for large scale practical production. These results indicate the leaf-like CuO-Cu 2 O/Cu foam electrode would be a promising electrode for high-performance supercapacitor applications.

Cu@C nanoporous composites containing little copper oxides derived from dimethyl imidazole modified MOF199 as electrocatalysts for hydrogen evolution reaction

NASA Astrophysics Data System (ADS)

Wei, Xuedong; Li, Na; Zhang, Xianming

2017-12-01

It remains a huge challenge to develop non precious electrocatalysts with high activity to substitute commercial Pt catalysts for hydrogen evolution reactions (HER). Here, the C-Cu-DI and C-Cu materials with the copper based nanoporous carbon structures were synthesized by carbonizing MOF199 and DI-MOF199. The composite structure and HER electrocatalytic properties of the C-Cu-DI and C-Cu materials are studied. The results show that C-Cu-DI and C-Cu samples exhibit good catalytic activity. And C-Cu-DI sample through the addition of Dimethyl imidazole(DI) in the DI-MOF199 precursor has higher electrocatalytic activity than the C-Cu sample. The superior catalytic activity is attributed to the special composite structure of nanoscale deposition particles on the framework with plenty of nano pores and nano copper and few copper oxidation particles distributed or wrapped into the amorphous porous carbon phase. The nano copper and few copper oxidation particles in the C-Cu and C-Cu-DI catalysts maybe provide the more effective catalytic activity sites. The C-Cu-DI composite with large size spherical hollow deposition particles has higher conductivity, better BET surface area and reasonable micro-meso-macro porous distribution, so the overpotentials at the current density of 1 mA cm-2 and 10 mA cm-2 are respectively 270 mV and 390 mV vs. RHE. Although the HER activity has a big gap with commercial platinum catalyst, this study can provide an important experimental exploration for the design of copper based non noble metal/nano porous carbon composite HER electrocatalyst.

Iron, zinc, and copper in retinal physiology and disease.

PubMed

Ugarte, Marta; Osborne, Neville N; Brown, Laurence A; Bishop, Paul N

2013-01-01

The essential trace metals iron, zinc, and copper play important roles both in retinal physiology and disease. They are involved in various retinal functions such as phototransduction, the visual cycle, and the process of neurotransmission, being tightly bound to proteins and other molecules to regulate their structure and/or function or as unbound free metal ions. Elevated levels of "free" or loosely bound metal ions can exert toxic effects, and in order to maintain homeostatic levels to protect retinal cells from their toxicity, appropriate mechanisms exist such as metal transporters, chaperones, and the presence of certain storage molecules that tightly bind metals to form nontoxic products. The pathways to maintain homeostatic levels of metals are closely interlinked, with various metabolic pathways directly and/or indirectly affecting their concentrations, compartmentalization, and oxidation/reduction states. Retinal deficiency or excess of these metals can result from systemic depletion and/or overload or from mutations in genes involved in maintaining retinal metal homeostasis, and this is associated with retinal dysfunction and pathology. Iron accumulation in the retina, a characteristic of aging, may be involved in the pathogenesis of retinal diseases such as age-related macular degeneration (AMD). Zinc deficiency is associated with poor dark adaptation. Zinc levels in the human retina and RPE decrease with age in AMD. Copper deficiency is associated with optic neuropathy, but retinal function is maintained. The changes in iron and zinc homeostasis in AMD have led to the speculation that iron chelation and/or zinc supplements may help in its treatment. Copyright © 2013 Elsevier Inc. All rights reserved.

Impact of ionophore monensin on performance and Cu uptake in earthworm Eisenia andrei exposed to copper-contaminated soil.

PubMed

Zidar, Primož; Kos, Monika; Vogel-Mikuš, Katarina; van Elteren, Johannes Teun; Debeljak, Marta; Žižek, Suzana

2016-10-01

Exposure of beneficial soil organisms to chemical mixtures is of great concern and can result in unexpected deleterious consequences. We investigated the effects of concurrent soil contamination with monensin, a veterinary pharmaceutical and feed additive, and copper, on earthworm copper uptake and reproductive success. The animals were exposed for 14 or 28 days to both substances and the results showed that the Cu body burden of earthworms increases in the presence of monensin. The harmful effects of Cu on earthworm cocoon production were considerably higher when monensin was also present in the soil. To localise the copper in earthworm tissues, histological staining was performed using two different dyes (rubeanic acid and 5-4-(p-dimethylaminobenzylidene)-rhodanine). Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used to quantify the Cu levels in the tissues. Cu was found predominantly in the gut wall. The Cu content in the body wall was at least ten times lower compared to the gut, but was proportional to the level of soil contamination. Concurrent soil contamination with monensin and copper resulted in higher earthworm Cu levels and in decreased reproductive success of these important soil decomposers. Copyright © 2016 Elsevier Ltd. All rights reserved.

Susceptibility of 169 USA300 methicillin-resistant Staphylococcus aureus isolates to two copper-based biocides, CuAL42 and CuWB50.

PubMed

Luna, Vicki Ann; Hall, Tony J; King, Debbie S; Cannons, Andrew C

2010-05-01

To test the activity of two copper-based biocides, CuAL42 and CuWB50, and benzalkonium chloride against 169 isolates of methicillin-resistant Staphylococcus aureus (MRSA) pulsotype USA300, a virulent, multiply resistant, widespread clone in the USA. Tests including MIC, MBC and time-kill studies were performed multiple times. The MIC range, MIC(50) and MIC(90) (0.59-18.75, 4.69 and 4.69 ppm, respectively) and the MBC range, MBC(50) and MBC(90) (1.17-18.75, 4.69 and 9.38 ppm, respectively) for CuAL42 were identical with those obtained with CuWB50, except that the MBC range for CuWB50 was wider (0.59-37.5 ppm). In time-kill studies, a 6 log(10) reduction of cfu was achieved within 1 h (150 ppm) and 0.5 h (300 ppm) for CuAL42, and 1.5 h (150 ppm) and 0.75 h (300 ppm) for CuWB50. Both copper-based biocides can effectively kill USA300 MRSA and may facilitate the eradication of the organism from healthcare settings.

Iron Oxide-Supported Copper Oxide Nanoparticles (Nanocat-Fe-CuO): Magnetically Recyclable Catalysts for the Synthesis of Pyrazole Derivatives, 4-Methoxyaniline, and Ullmann-type Condensation Reactions

EPA Science Inventory

An efficient and benign protocol is reported for the synthesis of 4-methoxyaniline, medicinally important pyrazole derivatives, and Ullmann-type condensation reaction using magnetically separable and reusable magnetite-supported copper (nanocat-Fe-CuO) nanoparticles under mild co...

HRTEM/AEM and SEM study of fluid-rock interactions: Interaction of copper, silver, selenium, chromium, and cadmium-bearing solutions with geological materials at near surface conditions, with an emphasis on phyllosilicates. Progress report, September 1, 1992--September 1, 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veblen, D.R.; Ilton, E.S.

1993-05-01

TEM of naturally occurring Cu-rich biotites and feldspars from weathered portions of porphyry copper deposits has shown that copper is not in the structure of these minerals, is present in their weathering products such as copper-rich vermiculite layers, submicroscopic iron oxyhydroxides and native copper inclusions, and chrysocoua. Reaction of acidic solutions bearing-Cu{sup 2+}, Ag{sup +}, Cr{sup 6+}, and Se{sup 4+}, at 25C, with biotite indicates that ferrous iron in biotite can reduce Cu{sup 2+}, Ag+, and Cr{sup 6+} to Cu{degrees}, Ag{degrees}, and Cr(III), respectively. However, Se{sup 4+} does not appear to be reduced. Copper is reduced in the interlayer region,more » silver is reduced in the interlayer and on the biotite surfaces, and chromium is reduced at the biotite surface. TEM shows that the reduction of copper and silver by biotite can produce native metal inclusions, whereas reduction of Cr(VI) to CR(III) did not produce any Cr-bearing precipitates. The copper and silver experiments show that iron in biotite can be a much stronger reducing agent than iron in solution. TEM and XPS of biotites reacted with CR(VI) clearly show that edges or (hkO) faces are much more reactive than the basal planes, where the edges are strongly enriched in CR(III) relative to the basal planes. In contrast, biotites reacted with Cr(IH)-bearing solutions show little fractionation between the edges and basal planes. Another important result of our XPS studies is that we demonstrated that the oxidation state of near surface iron in biotite can be quantified.« less

Auger electron spectroscopy study of surface segregation in the binary alloys copper-1 atomic percent indium, copper-2 atomic percent tin, and iron-6.55 atomic percent silicon

NASA Technical Reports Server (NTRS)

Ferrante, J.

1973-01-01

Auger electron spectroscopy was used to examine surface segregation in the binary alloys copper-1 at. % indium, copper-2 at. % tin and iron-6.55 at. % silicon. The copper-tin and copper-indium alloys were single crystals oriented with the /111/ direction normal to the surface. An iron-6.5 at. % silicon alloy was studied (a single crystal oriented in the /100/ direction for study of a (100) surface). It was found that surface segregation occurred following sputtering in all cases. Only the iron-silicon single crystal alloy exhibited equilibrium segregation (i.e., reversibility of surface concentration with temperature) for which at present we have no explanation. McLean's analysis for equilibrium segregation at grain boundaries did not apply to the present results, despite the successful application to dilute copper-aluminum alloys. The relation of solute atomic size and solubility to surface segregation is discussed. Estimates of the depth of segregation in the copper-tin alloy indicate that it is of the order of a monolayer surface film.

Fabrication of Copper-Rich Cu-Al Alloy Using the Wire-Arc Additive Manufacturing Process

NASA Astrophysics Data System (ADS)

Dong, Bosheng; Pan, Zengxi; Shen, Chen; Ma, Yan; Li, Huijun

2017-12-01

An innovative wire-arc additive manufacturing (WAAM) process is used to fabricate Cu-9 at. pct Al on pure copper plates in situ, through separate feeding of pure Cu and Al wires into a molten pool, which is generated by the gas tungsten arc welding (GTAW) process. After overcoming several processing problems, such as opening the deposition molten pool on the extremely high-thermal conductive copper plate and conducting the Al wire into the molten pool with low feed speed, the copper-rich Cu-Al alloy was successfully produced with constant predesigned Al content above the dilution-affected area. Also, in order to homogenize the as-fabricated material and improve the mechanical properties, two further homogenization heat treatments at 1073 K (800 °C) and 1173 K (900 °C) were applied. The material and mechanical properties of as-fabricated and heat-treated samples were compared and analyzed in detail. With increased annealing temperatures, the content of precipitate phases decreased and the samples showed gradual improvements in both strength and ductility with little variation in microstructures. The present research opened a gate for in-situ fabrication of Cu-Al alloy with target chemical composition and full density using the additive manufacturing process.

Methods for making a supported iron-copper catalyst

DOEpatents

Dyer, Paul N.; Pierantozzi, Ronald

1986-01-01

A catalyst is described for the synthesis of hydrocarbons from CO+H.sub.2 utilizing a porous Al.sub.2 O.sub.3 support impregnated with iron and copper and optionally promoted with an alkali metal. The use of an Al.sub.2 O.sub.3 support results in the suppression of heavy waxes (C.sub.26 + hydrocarbons), particularly in slurry phase operation, when compared to unsupported or co-precipitated catalysts.

Influence of biochars, compost and iron grit, alone and in combination, on copper solubility and phytotoxicity in a Cu-contaminated soil from a wood preservation site.

PubMed

Oustriere, Nadège; Marchand, Lilian; Galland, William; Gabbon, Lunel; Lottier, Nathalie; Motelica, Mikael; Mench, Michel

2016-10-01

Two biochars, a green waste compost and iron grit were used, alone and in combination, as amendment to improve soil properties and in situ stabilize Cu in a contaminated soil (964mgCukg(-1)) from a wood preservation site. The pot experiment consisted in 9 soil treatments (% w/w): untreated Cu-contaminated soil (Unt); Unt soil amended respectively with compost (5%, C), iron grit (1%, Z), pine bark-derived biochar (1%, PB), poultry-manure-derived biochar (1%, AB), PB or AB+C (5%, PBC and ABC), and PB or AB+Z (1%, PBZ and ABZ). After a 3-month reaction period, the soil pore water (SPW) was sampled in potted soils and dwarf beans were grown for a 2-week period. In the SPW, all amendments decreased the Cu(2+) concentration, but total Cu concentration increased in all AB-amended soils due to high dissolved organic matter (DOM) concentration. No treatment improved root and shoot DW yields, which even decreased in the ABC and ABZ treatments. The PBZ treatment decreased total Cu concentration in the SPW while reducing the gap with common values for root and shoot yields of dwarf bean plants. A field trial is underway before any recommendation for the PB-based treatments. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of copper oxide nanomaterials (CuONMs) are life stage dependent - full life cycle in Enchytraeus crypticus.

PubMed

Bicho, Rita C; Santos, Fátima C F; Scott-Fordsmand, Janeck J; Amorim, Mónica J B

2017-05-01

Copper oxide nanomaterials (CuONMs) have various applications in industry and enter the terrestrial environment, e.g. via sewage sludge. The effects of CuONMs and copper chloride (CuCl 2 ) were studied comparing the standard enchytraeid reproduction test (ERT) and the full life cycle test (FLCt) with Enchytraeus crypticus. CuONMs mainly affected growth or juveniles' development, whereas CuCl 2 mainly affected embryo development and/or hatching success and adults survival. Compared to the ERT, the FLCt allowed discrimination of effects between life stages and provided indication of the underlying mechanisms; further, the FLCt showed increased sensitivity, e.g. reproductive effects for CuONMs: EC 10  = 8 mg Cu/kg and EC 10  = 421 mg Cu/kg for the FLCt and the ERT respectively. The performance of the FLCt is preferred to the ERT and we recommend it as a good alternative to assess hazard of NMs. Effects of CuONMs and CuCl 2 are life stage dependent and are different between Cu forms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Crystallization Behavior of Copper Smelter Slag During Molten Oxidation

NASA Astrophysics Data System (ADS)

Fan, Yong; Shibata, Etsuro; Iizuka, Atsushi; Nakamura, Takashi

2015-10-01

Copper slag is composed of iron silicate obtained by smelting copper concentrate and silica flux. One of the most important criteria for the utilization of this secondary resource is the recovery of iron from the slag matrix to decrease the volume of dumped slag. The molten oxidation process with crushing magnetic separation appears to be a more sustainable approach and is based on directly blowing oxidizing gas onto molten slag after the copper smelting process. In the current study, using an infrared furnace, the crystallization behavior of the slag during molten oxidation was studied to better understand the trade-off between magnetite and hematite precipitations, as assessed by X-ray diffraction (using an internal standard). Furthermore, the crystal morphology was examined using a laser microscope and Raman imaging system to understand the iron oxide transformation, and the distribution of impurities such as Cu, Zn, As, Cr, and Pb were complemented with scanning electron microscopy and energy dispersive spectroscopy. In addition, the reaction mechanism was investigated with a focus on the oxidation processes.

Oxidized nanocrystalline Fe-Cu pseudoalloy subjected to high pressure and electrodischarge pulses: Mössbauer and x-ray investigations

NASA Astrophysics Data System (ADS)

Gavriliuk, A. G.; Voitkovsky, V. S.; Sidorov, V. A.; Filonenko, V. P.; Tsiok, O. B.; Khvostantsev, L. G.

1998-05-01

Nanocrystalline Fe15Cu85 pseudoalloy has been subjected to pulsed heating up to 1500 K at high pressure (8 GPa). Two regimes were studied: the direct heating using electrodischarge through the sample and indirect heating with the use of cylindrical heater around the sample. The temperature and time conditions in both types of experiments were adjusted to be equivalent. The discharge parameters (stored energy, discharge time, and magnitude of current pulse) were sufficient to move defects by conduction electrons, but insufficient to melt the sample. The properties of treated samples were studied using Mössbauer absorption spectra and x-ray diffraction for three types of samples: (a) primary powder treated by high pressure up to 8 GPa, (b) powder subjected to indirect pulsed heating at 8 GPa, (c) powder treated by electrical pulses at 8 GPa. The x-ray diffraction pattern of primary powder exhibits peaks of copper, iron, and copper oxide (CuO). The Mössbauer spectrum of primary powder exhibits six peaks of alpha iron and some peaks near zero velocity due to the small iron clusters in the copper matrix and ultrafine clusters of paramagnetic phase x-Fe2O3. The transformation of CuO to Cu2O takes place in the course of indirect heating, the Mössbauer spectrum being almost unchanged. The direct electrodischarge heating causes the appearance of new magnetic phase with the magnetic field on iron nucleus 505 kOe, which corresponds to α-Fe2O3. The formation of α-Fe2O3 was confirmed by x-ray diffraction. At the same time the transformation of CuO to Cu2O is incomplete. These experiments demonstrate that high density current pulses, causing the electron wind, can be a useful tool to influence the structure of nanocrystalline powder.

Study of copper (Cu) contents in blood cockles (Anadara sp.) at Surabaya coastal waters

NASA Astrophysics Data System (ADS)

Alfionita, S.; Pursetyo, K. T.; Sahidu, A. M.

2018-04-01

Heavy metal pollution categorized as harmful effect on the environment. This study aims to determine the content and the rate of accumulation of heavy metals copper (Cu) in the mussel of cockles (Anadara sp.) This study uses observation method with descriptive analysis. The test results Cu in sea water was <0.0223 mg/L. The results have exceeded the water quality standard according to state environmental ministerial decree number 51 2004 on marine water quality standards for marine biota maximum limit of Cu in sea water is 0.008 mg/L. Copper concentration in the sediment of 6.16 mg/kg at the Wonokromo station and at the Dadapan station is 4.03 mg/kg. According to the US-EPA in 2004 on the instructions of sediment pollution classification 49.98 mg Cu/kg. The results of shells fur Cu on Wonokromo was 1.833 mg/kg and Dadapan was 1.352 mg/kg. According to the MOH Decree No.0375/B/SK/1989 about Quality Standard Biota Consumption of Metals to the maximum limit of the existing Cu concentrations in marine biota was 20 ppm or 20 mg / kg so that the content of Cu in shellfish feathers still below the limit of existing quality standards.

Mechanism of Copper Uptake from Blood Plasma Ceruloplasmin by Mammalian Cells

PubMed Central

Ramos, Danny; Vargas, Rebecca; Gaite, Michaella; Montgomery, Aaron; Linder, Maria C.

2016-01-01

Ceruloplasmin, the main copper binding protein in blood plasma, has been of particular interest for its role in efflux of iron from cells, but has additional functions. Here we tested the hypothesis that it releases its copper for cell uptake by interacting with a cell surface reductase and transporters, producing apoceruloplasmin. Uptake and transepithelial transport of copper from ceruloplasmin was demonstrated with mammary epithelial cell monolayers (PMC42) with tight junctions grown in bicameral chambers, and purified human 64Cu-labeled ceruloplasmin secreted by HepG2 cells. Monolayers took up virtually all the 64Cu over 16h and secreted half into the apical (milk) fluid. This was partly inhibited by Ag(I). The 64Cu in ceruloplasmin purified from plasma of 64Cu-injected mice accumulated linearly in mouse embryonic fibroblasts (MEFs) over 3-6h. Rates were somewhat higher in Ctr1+/+ versus Ctr1-/- cells, and 3-fold lower at 2°C. The ceruloplasmin-derived 64Cu could not be removed by extensive washing or trypsin treatment, and most was recovered in the cytosol. Actual cell copper (determined by furnace atomic absorption) increased markedly upon 24h exposure to holoceruloplasmin. This was accompanied by a conversion of holo to apoceruloplasmin in the culture medium and did not occur during incubation in the absence of cells. Four different endocytosis inhibitors failed to prevent 64Cu uptake from ceruloplasmin. High concentrations of non-radioactive Cu(II)- or Fe(III)-NTA (substrates for cell surface reductases), or Cu(I)-NTA (to compete for transporter uptake) almost eliminated uptake of 64Cu from ceruloplasmin. MEFs had cell surface reductase activity and expressed Steap 2 (but not Steaps 3 and 4 or dCytB). However, six-day siRNA treatment was insufficient to reduce activity or uptake. We conclude that ceruloplasmin is a circulating copper transport protein that may interact with Steap2 on the cell surface, forming apoceruloplasmin, and Cu(I) that enters cells

Copper Metallochaperones

PubMed Central

Robinson, Nigel J.; Winge, Dennis R.

2014-01-01

The current state of knowledge on how copper metallochaperones support the maturation of cuproproteins is reviewed. Copper is needed within mitochondria to supply the CuA and intramembrane CuB sites of cytochrome oxidase, within the trans-Golgi network to supply secreted cuproproteins and within the cytosol to supply superoxide dismutase 1 (Sod1). Subpopulations of copper-zinc superoxide dismutase also localize to mitochondria, the secretory system, the nucleus and, in plants, the chloroplast, which also requires copper for plastocyanin. Prokaryotic cuproproteins are found in the cell membrane and in the periplasm of gram-negative bacteria. Cu(I) and Cu(II) form tight complexes with organic molecules and drive redox chemistry, which unrestrained would be destructive. Copper metallochaperones assist copper in reaching vital destinations without inflicting damage or becoming trapped in adventitious binding sites. Copper ions are specifically released from copper metallochaperones upon contact with their cognate cuproproteins and metal transfer is thought to proceed by ligand substitution. PMID:20205585

Cu isotopes in marine black shales record the Great Oxidation Event

PubMed Central

Rodríguez, Nathalie P.; Partin, Camille A.; Andersson, Per; Weiss, Dominik J.; El Albani, Abderrazak; Rodushkin, Ilia; Konhauser, Kurt O.

2016-01-01

The oxygenation of the atmosphere ∼2.45–2.32 billion years ago (Ga) is one of the most significant geological events to have affected Earth’s redox history. Our understanding of the timing and processes surrounding this key transition is largely dependent on the development of redox-sensitive proxies, many of which remain unexplored. Here we report a shift from negative to positive copper isotopic compositions (δ65CuERM-AE633) in organic carbon-rich shales spanning the period 2.66–2.08 Ga. We suggest that, before 2.3 Ga, a muted oxidative supply of weathering-derived copper enriched in 65Cu, along with the preferential removal of 65Cu by iron oxides, left seawater and marine biomass depleted in 65Cu but enriched in 63Cu. As banded iron formation deposition waned and continentally sourced Cu became more important, biomass sampled a dissolved Cu reservoir that was progressively less fractionated relative to the continental pool. This evolution toward heavy δ65Cu values coincides with a shift to negative sedimentary δ56Fe values and increased marine sulfate after the Great Oxidation Event (GOE), and is traceable through Phanerozoic shales to modern marine settings, where marine dissolved and sedimentary δ65Cu values are universally positive. Our finding of an important shift in sedimentary Cu isotope compositions across the GOE provides new insights into the Precambrian marine cycling of this critical micronutrient, and demonstrates the proxy potential for sedimentary Cu isotope compositions in the study of biogeochemical cycles and oceanic redox balance in the past. PMID:27091980

A Holistic Model That Physicochemically Links Iron Oxide - Apatite and Iron Oxide - Copper - Gold Deposits to Magmas

NASA Astrophysics Data System (ADS)

Simon, A. C.; Reich, M.; Knipping, J.; Bilenker, L.; Barra, F.; Deditius, A.; Lundstrom, C.; Bindeman, I. N.

2015-12-01

Iron oxide-apatite (IOA) and iron oxide-copper-gold deposits (IOCG) are important sources of their namesake metals and increasingly for rare earth metals in apatite. Studies of natural systems document that IOA and IOCG deposits are often spatially and temporally related with one another and coeval magmatism. However, a genetic model that accounts for observations of natural systems remains elusive, with few observational data able to distinguish among working hypotheses that invoke meteoric fluid, magmatic-hydrothermal fluid, and immiscible melts. Here, we use Fe and O isotope data and high-resolution trace element (e.g., Ti, V, Mn, Al) data of individual magnetite grains from the world-class Los Colorados (LC) IOA deposit in the Chilean Iron Belt to elucidate the origin of IOA and IOCG deposits. Values of d56Fe range from 0.08‰ to 0.26‰, which are within the global range of ~0.06‰ to 0.5‰ for magnetite formed at magmatic conditions. Values of δ18O for magnetite and actinolite are 2.04‰ and 6.08‰, respectively, consistent with magmatic values. Ti, V, Al, and Mn are enriched in magnetite cores and decrease systematically from core to rim. Plotting [Al + Mn] vs. [Ti + V] indicates that magnetite cores are consistent with magmatic and/or magmatic-hydrothermal (i.e., porphyry) magnetites. Decreasing Al, Mn, Ti, V is consistent with a cooling trend from porphyry to Kiruna to IOCG systems. The data from LC are consistent with the following new genetic model for IOA and IOCG systems: 1) magnetite cores crystallize from silicate melt; 2) these magnetite crystals are nucleation sites for aqueous fluid that exsolves and scavenges inter alia Fe, P, S, Cu, Au from silicate melt; 3) the magnetite-fluid suspension is less dense that the surrounding magma, allowing ascent; 4) as the suspension ascends, magnetite grows in equilibrium with the fluid and takes on a magmatic-hydrothermal character (i.e., lower Al, Mn, Ti, V); 5) during ascent, magnetite, apatite and

The role of iron and copper molecules in the neuronal vulnerability of locus coeruleus and substantia nigra during aging

PubMed Central

Zecca, Luigi; Stroppolo, Antonella; Gatti, Alberto; Tampellini, Davide; Toscani, Marco; Gallorini, Mario; Giaveri, Giuseppe; Arosio, Paolo; Santambrogio, Paolo; Fariello, Ruggero G.; Karatekin, Erdem; Kleinman, Mark H.; Turro, Nicholas; Hornykiewicz, Oleh; Zucca, Fabio A.

2004-01-01

In this study, a comparative analysis of metal-related neuronal vulnerability was performed in two brainstem nuclei, the locus coeruleus (LC) and substantia nigra (SN), known targets of the etiological noxae in Parkinson's disease and related disorders. LC and SN pars compacta neurons both degenerate in Parkinson's disease and other Parkinsonisms; however, LC neurons are comparatively less affected and with a variable degree of involvement. In this study, iron, copper, and their major molecular forms like ferritins, ceruloplasmin, neuromelanin (NM), manganese-superoxide dismutase (SOD), and copper/zinc-SOD were measured in LC and SN of normal subjects at different ages. Iron content in LC was much lower than that in SN, and the ratio heavy-chain ferritin/iron in LC was higher than in the SN. The NM concentration was similar in LC and SN, but the iron content in NM of LC was much lower than SN. In both regions, heavy- and light-chain ferritins were present only in glia and were not detectable in neurons. These data suggest that in LC neurons, the iron mobilization and toxicity is lower than that in SN and is efficiently buffered by NM. The bigger damage occurring in SN could be related to the higher content of iron. Ferritins accomplish the same function of buffering iron in glial cells. Ceruloplasmin levels were similar in LC and SN, but copper was higher in LC. However, the copper content in NM of LC was higher than that of SN, indicating a higher copper mobilization in LC neurons. Manganese-SOD and copper/zinc-SOD had similar age trend in LC and SN. These results may explain at least one of the reasons underlying lower vulnerability of LC compared to SN in Parkinsonian syndromes. PMID:15210960

[Performance Study of Bromochloracetonitrile Degradation in Drinking Water by Fe/Cu Catalytic Reduction].

PubMed

Ding, Chun-sheng; Ma, Hai-long; Fu, Yang-ping; Zhao, Shi-du; Li, Dong-bing

2015-06-01

The paper used the method of iron copper catalyst reduction to degrade low concentrations of bromochloracetonitrile (BCAN) to lighten the damage to human being, which is a kind of disinfection by-products (DBPs) produced during the chlorination process of drinking water. The removal efficiency of BCAN and its influencing factors were investigated. The mechanism of degradation and kinetics were also explored. The results indicated that iron copper had a greater degradation ability towards BCAN, and the degradation rate of iron copper (mass ratio of 10:1) was 1.5 times that of the zero-valent iron. The removal of BCAN increased obviously with the increase of Fe/Cu dosage. When the initial concentration was set at 20 microg x L(-1), after a reaction time of 150 min, removal of BCAN was improved from 51.1% to 89.5% with the increase of iron copper (mass ratio of 10:1) dosage from 5 g x L(-1) to 10 g x L(-1). The temperature also had great impact on BCAN removal and the removal increased with the increase of temperature. However, BCAN removal did not change a lot with the variation of the initial concentration of BCAN when it was at a low level. The BCAN degradation by iron copper catalytic-reduction followed the first-order kinetics model.

The interplay between siderophore secretion and coupled iron and copper transport in the heterocyst-forming cyanobacterium Anabaena sp. PCC 7120.

PubMed

Nicolaisen, Kerstin; Hahn, Alexander; Valdebenito, Marianne; Moslavac, Suncana; Samborski, Anastazia; Maldener, Iris; Wilken, Corinna; Valladares, Ana; Flores, Enrique; Hantke, Klaus; Schleiff, Enrico

2010-11-01

Iron uptake is essential for Gram-negative bacteria including cyanobacteria. In cyanobacteria, however, the iron demand is higher than in proteobacteria due to the function of iron as a cofactor in photosynthesis and nitrogen fixation, but our understanding of iron uptake by cyanobacteria stands behind the knowledge in proteobacteria. Here, two genes involved in this process in the heterocyst-forming cyanobacterium Anabaena sp. PCC 7120 were identified. ORF all4025 encodes SchE, a putative cytoplasmic membrane-localized transporter involved in TolC-dependent siderophore secretion. Inactivation of schE resulted in an enhanced sensitivity to high metal concentrations and decreased secretion of hydroxamate-type siderophores. ORF all4026 encodes a predicted outer membrane-localized TonB-dependent iron transporter, IacT. Inactivation of iacT resulted in decreased sensitivity to elevated iron and copper levels. Expression of iacT from the artificial trc promoter (P(trc)) resulted in sensitization against tested metals. Further analysis showed that iron and copper effects are synergistic because a decreased supply of iron induced a significant decrease of copper levels in the iacT insertion mutant but an increase of those levels in the strain carrying P(trc)-iacT. Our results unravel a link between iron and copper homeostasis in Anabaena sp. PCC 7120. Copyright © 2010 Elsevier B.V. All rights reserved.

ON THE RELATIVE STABILITY OF ALUMINUM, TITANIUM, VANADIUM, IRON, AND COPPER TARTRATE COMPLEXES IN ALKALI MEDIA (in Russian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pyatnitskii, I.V.; Kostyshina, A.P.

1959-06-01

The stability of aluminum, copper, iron, titunium, and vanadium tartrate complexes was determined using bond magnitudes as criteria (the ratio between the concentrations of complexed and free ions at a certain standard acid condition). A method is suggested for determining the ratio of the bonds combining the complexes of two metals. The partition constaats of aluminum, copper, iron(III), and vanadium hydroxyquinolinates between the aqueous solution and chloroform were 2.6 x 10/sup -33/, 7.3 x 10/sup -23/, 1.5 x 10/sup -37/, and 4.2 x 10/sup -23/, respectively. The relative stability of copper and iron turtrate complexes in alkali solution (pH 13)more » and aluminum, iron(III), titunium, and vanadium(IV) tartrate complexes in ammonium solution (pH 9.5) was determined. (R.V.J.)« less

A functional screen for copper homeostasis genes identifies a pharmacologically tractable cellular system

PubMed Central

2014-01-01

Background Copper is essential for the survival of aerobic organisms. If copper is not properly regulated in the body however, it can be extremely cytotoxic and genetic mutations that compromise copper homeostasis result in severe clinical phenotypes. Understanding how cells maintain optimal copper levels is therefore highly relevant to human health. Results We found that addition of copper (Cu) to culture medium leads to increased respiratory growth of yeast, a phenotype which we then systematically and quantitatively measured in 5050 homozygous diploid deletion strains. Cu’s positive effect on respiratory growth was quantitatively reduced in deletion strains representing 73 different genes, the function of which identify increased iron uptake as a cause of the increase in growth rate. Conversely, these effects were enhanced in strains representing 93 genes. Many of these strains exhibited respiratory defects that were specifically rescued by supplementing the growth medium with Cu. Among the genes identified are known and direct regulators of copper homeostasis, genes required to maintain low vacuolar pH, and genes where evidence supporting a functional link with Cu has been heretofore lacking. Roughly half of the genes are conserved in man, and several of these are associated with Mendelian disorders, including the Cu-imbalance syndromes Menkes and Wilson’s disease. We additionally demonstrate that pharmacological agents, including the approved drug disulfiram, can rescue Cu-deficiencies of both environmental and genetic origin. Conclusions A functional screen in yeast has expanded the list of genes required for Cu-dependent fitness, revealing a complex cellular system with implications for human health. Respiratory fitness defects arising from perturbations in this system can be corrected with pharmacological agents that increase intracellular copper concentrations. PMID:24708151

Binuclear Cu A formation in biosynthetic models of Cu A in azurin proceeds via a novel Cu(Cys) 2His mononuclear copper intermediate

DOE PAGES

Chakraborty, Saumen; Polen, Michael J.; Chacon, Kelly N.; ...

2015-09-09

Cu A is a binuclear electron transfer (ET) center found in cytochrome c oxidases (C cOs), nitrous oxide reductases (N 2ORs), and nitric oxide reductase (NOR). In these proteins, the Cu A centers facilitate efficient ET ( k ET > 10 4 s –1) under low thermodynamic driving forces (10–90 mV). While the structure and functional properties of Cu A are well understood, a detailed mechanism of the incorporation of copper into the protein and the identity of the intermediates formed during the Cu A maturation process are still lacking. Previous studies of the Cu A assembly mechanism in vitromore » using a biosynthetic model Cu A center in azurin (Cu AAz) identified a novel intermediate X (I x) during reconstitution of the binuclear site. However, because of the instability of I x and the coexistence of other Cu centers, such as Cu A' and type 1 copper centers, the identity of this intermediate could not be established. In this paper, we report the mechanism of Cu A assembly using variants of Glu114XCu AAz (X = Gly, Ala, Leu, or Gln), the backbone carbonyl of which acts as a ligand to the Cu A site, with a major focus on characterization of the novel intermediate I x. We show that Cu A assembly in these variants proceeds through several types of Cu centers, such as mononuclear red type 2 Cu, the novel intermediate I x, and blue type 1 Cu. Our results show that the backbone flexibility of the Glu114 residue is an important factor in determining the rates of T2Cu → I x formation, suggesting that Cu A formation is facilitated by swinging of the ligand loop, which internalizes the T2Cu capture complex to the protein interior. The kinetic data further suggest that the nature of the Glu114 side chain influences the time scales on which these intermediates are formed, the wavelengths of the absorption peaks, and how cleanly one intermediate is converted to another. Through careful understanding of these mechanisms and optimization of the conditions, we have obtained I x in

Development and characterization of laser surface cladding (Ti,W)C reinforced Ni-30Cu alloy composite coating on copper

NASA Astrophysics Data System (ADS)

Yan, Hua; Zhang, Peilei; Yu, Zhishui; Li, Chonggui; Li, Ruidi

2012-07-01

To improve the wear resistance of copper components, laser surface cladding (LSC) was applied to deposit (Ti,W)C reinforced Ni-30Cu alloy composite coating on copper using a cladding interlayer of Ni-30Cu alloy by Nd:YAG laser. The microstructure and phases of the composite coating were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray energy dispersive microanalysis (EDX). Microhardness tester and pin-on-disc wear tester were employed to evaluate the hardness and dry-sliding wear resistance. The results show that crack-free composite coating with metallurgical bonding to the copper substrate is obtained. Phases identified in the (Ti,W)C-reinforced Ni-30Cu alloy composite layer are composed of TiWC2 reinforcements and (Ni,Cu) solid solution. TiWC2 reinforcements are distributed uniformly in the (Ni,Cu) solid solution matrix with dendritic morphology in the upper region and with particles in the mid-lower region. The microhardness and wear properties of the composite coating are improved significantly in comparison to the as-received copper substrate due to the addition of 50 wt% (Ti,W)C multicarbides.

Kinetics of bulk photo-initiated copper(i)-catalyzed azide–alkyne cycloaddition (CuAAC) polymerizations†

PubMed Central

Song, Han Byul; Baranek, Austin; Bowman, Christopher N.

2016-01-01

Photoinitiation of polymerizations based on the copper(i)-catalyzed azide–alkyne cycloaddition (CuAAC) reaction enables spatio-temporal control and the formation of mechanically robust, highly glassy photopolymers. Here, we investigated several critical factors influencing photo-CuAAC polymerization kinetics via systematic variation of reaction conditions such as the physicochemical nature of the monomers; the copper salt and photoinitiator types and concentrations; light intensity; exposure time and solvent content. Real time Fourier transform infrared spectroscopy (FTIR) was used to monitor the polymerization kinetics in situ. Six different di-functional azide monomers and four different tri-functional alkyne monomers containing either aliphatic, aromatic, ether and/or carbamate substituents were synthesized and polymerized. Replacing carbamate structures with ether moieties in the monomers enabled an increase in conversion from 65% to 90% under similar irradiation conditions. The carbamate results in stiffer monomers and higher viscosity mixtures indicating that chain mobility and diffusion are key factors that determine the CuAAC network formation kinetics. Photoinitiation rates were manipulated by altering various aspects of the photo-reduction step; ultimately, a loading above 3 mol% per functional group for both the copper catalyst and the photoinitiator showed little or no rate dependence on concentration while a loading below 3 mol% exhibited 1st order rate dependence. Furthermore, a photoinitiating system consisting of camphorquinone resulted in 60% conversion in the dark after only 1 minute of 75 mW cm−2 light exposure at 400–500 nm, highlighting a unique characteristic of the CuAAC photopolymerization enabled by the combination of the copper(i)’s catalytic lifetime and the nature of the step-growth polymerization. PMID:27429650

Kinetics of bulk photo-initiated copper(i)-catalyzed azide-alkyne cycloaddition (CuAAC) polymerizations.

PubMed

Song, Han Byul; Baranek, Austin; Bowman, Christopher N

2016-01-21

Photoinitiation of polymerizations based on the copper(i)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction enables spatio-temporal control and the formation of mechanically robust, highly glassy photopolymers. Here, we investigated several critical factors influencing photo-CuAAC polymerization kinetics via systematic variation of reaction conditions such as the physicochemical nature of the monomers; the copper salt and photoinitiator types and concentrations; light intensity; exposure time and solvent content. Real time Fourier transform infrared spectroscopy (FTIR) was used to monitor the polymerization kinetics in situ . Six different di-functional azide monomers and four different tri-functional alkyne monomers containing either aliphatic, aromatic, ether and/or carbamate substituents were synthesized and polymerized. Replacing carbamate structures with ether moieties in the monomers enabled an increase in conversion from 65% to 90% under similar irradiation conditions. The carbamate results in stiffer monomers and higher viscosity mixtures indicating that chain mobility and diffusion are key factors that determine the CuAAC network formation kinetics. Photoinitiation rates were manipulated by altering various aspects of the photo-reduction step; ultimately, a loading above 3 mol% per functional group for both the copper catalyst and the photoinitiator showed little or no rate dependence on concentration while a loading below 3 mol% exhibited 1 st order rate dependence. Furthermore, a photoinitiating system consisting of camphorquinone resulted in 60% conversion in the dark after only 1 minute of 75 mW cm -2 light exposure at 400-500 nm, highlighting a unique characteristic of the CuAAC photopolymerization enabled by the combination of the copper(i)'s catalytic lifetime and the nature of the step-growth polymerization.

Sulfidation treatment of copper-containing plating sludge towards copper resource recovery.

PubMed

Kuchar, D; Fukuta, T; Onyango, M S; Matsuda, H

2006-11-02

The present study is concerned with the sulfidation treatment of copper-containing plating sludge towards copper resource recovery by flotation of copper sulfide from treated sludge. The sulfidation treatment was carried out by contacting simulated or real copper plating sludge with Na(2)S solution for a period of 5 min to 24 h. The initial molar ratio of S(2-) to Cu(2+) (S(2-) to Me(2+) in the case of real sludge) was adjusted to 1.00, 1.25 or 1.50, while the solid to liquid ratio was set at 1:50. As a result, it was found that copper compounds were converted to various copper sulfides within the first 5 min. In the case of simulated copper sludge, CuS was identified as the main sulfidation product at the molar ratio of S(2-) to Cu(2+) of 1.00, while Cu(7)S(4) (Roxbyite) was mainly found at the molar ratios of S(2-) to Cu(2+) of 1.50 and 1.25. Based on the measurements of oxidation-reduction potential, the formation of either CuS or Cu(7)S(4) at different S(2-) to Cu(2+) molar ratios was attributed to the changes in the oxidation-reduction potential. By contrast, in the case of sulfidation treatment of real copper sludge, CuS was predominantly formed, irrespective of S(2-) to Me(2+) molar ratio.

A Paramagnetic Copper(III) Complex Containing an Octahedral CuIII S6 Coordination Polyhedron.

PubMed

Krebs, Carsten; Glaser, Thorsten; Bill, Eckhard; Weyhermüller, Thomas; Meyer-Klaucke, Wolfram; Wieghardt, Karl

1999-02-01

Only the second octahedral, paramagnetic copper(III) complex (S=1) has now been synthesized and characterized. Six thiolato bridging ligands in the heterotrinuclear species [LCo III Cu III Co III L](ClO 4 ) 3 ⋅2 Me 2 CO (L=1,4,7-tris(4-tert-butyl-2-sulfidobenzyl)-1,4,7-triazacyclononane) stabilize this rare electron configuration. A section of the structure of the reduced form (Cu II , S=½) is shown. XAS, EXAFS, and EPR spectroscopy prove unambiguously that the one-electron oxidation to the copper(III) is metal- rather than ligand-centered. © 1999 WILEY-VCH Verlag GmbH, Weinheim, Fed. Rep. of Germany.

Physiological responses of coastal phytoplankton (Visakhapatnam, SW Bay of Bengal, India) to experimental copper addition.

PubMed

Biswas, Haimanti; Bandyopadhyay, Debasmita

2017-10-01

Trace amount of copper (Cu) is essential for many physiological processes; however, it can be potentially toxic at elevated levels. The impact of variable Cu concentrations on a coastal phytoplankton community was investigated along a coastal transect in SW Bay of Bengal. A small increase in Cu supply enhanced the concentrations of particulate organic carbon, particulate organic nitrogen, biogenic silica, total pigment, phytoplankton cell and total bacterial count. At elevated Cu levels all these parameters were adversely affected. δ 13 C POM and δ 15 N POC reflected a visible signature of both beneficial and toxic impacts of Cu supply. Skeletonema costatum, the dominant diatom species, showed higher tolerance to increasing Cu levels relative to Chaetoceros sp. Cyanobacteria showed greater sensitivity to copper than diatoms. The magnitude of Cu toxicity on the phytoplankton communities was inversely related to the distance from the coast. Co-enrichment of iron alleviated Cu toxicity to phytoplankton. Copyright © 2017 Elsevier Ltd. All rights reserved.

Production of brown and black pigments by using flotation waste from copper slag.

PubMed

Ozel, Emel; Turan, Servet; Coruh, Semra; Ergun, Osman Nuri

2006-04-01

One of the major problems in copper-producing countries is the treatment of the large amount of copper slag or copper flotation waste generated from copper slag which contains significant amounts of heavy metals such as Cu, Zn, Pb and Co. Dumping or disposal of such large quantities of flotation waste from copper slag causes environmental and space problems. In this study, the treatment of flotation waste from copper slag by a thermal method and its use as an iron source in the production of inorganic brown and black pigments that are used in the ceramic industry were investigated. The pigments were produced by calcining different amounts of flotation waste and chromite, Cr2O3, ZnO and CoO mixtures. The pigments obtained were added to transparent ceramic glazes and porcelainized tile bodies. Their colours were defined by L*a*b* measurements with a spectrophotometer. The results showed that flotation waste from copper slag could be used as an iron source to produce brown and black pigments in both ceramic body and glazes.

Strata-bound Fe-Co-Cu-Au-Bi-Y-REE deposits of the Idaho Cobalt Belt: Multistage hydrothermal mineralization in a magmatic-related iron oxide copper-gold system

USGS Publications Warehouse

Slack, John F.

2012-01-01

Mineralogical and geochemical studies of strata-bound Fe-Co-Cu-Au-Bi-Y-rare-earth element (REE) deposits of the Idaho cobalt belt in east-central Idaho provide evidence of multistage epigenetic mineralization by magmatic-hydrothermal processes in an iron oxide copper-gold (IOCG) system. Deposits of the Idaho cobalt belt comprise three types: (1) strata-bound sulfide lenses in the Blackbird district, which are cobaltite and, less commonly, chalcopyrite rich with locally abundant gold, native bismuth, bismuthinite, xenotime, allanite, monazite, and the Be-rich silicate gadolinite-(Y), with sparse uraninite, stannite, and Bi tellurides, in a gangue of quartz, chlorite, biotite, muscovite, garnet, tourmaline, chloritoid, and/or siderite, with locally abundant fluorapatite or magnetite; (2) discordant tourmalinized breccias in the Blackbird district that in places have concentrations of cobaltite, chalcopyrite, gold, and xenotime; and (3) strata-bound magnetite-rich lenses in the Iron Creek area, which contain cobaltiferous pyrite and locally sparse chalcopyrite or xenotime. Most sulfide-rich deposits in the Blackbird district are enclosed by strata-bound lenses composed mainly of Cl-rich Fe biotite; some deposits have quartz-rich envelopes.Whole-rock analyses of 48 Co- and/or Cu-rich samples show high concentrations of Au (up to 26.8 ppm), Bi (up to 9.16 wt %), Y (up to 0.83 wt %), ∑REEs (up to 2.56 wt %), Ni (up to 6,780 ppm), and Be (up to 1,180 ppm), with locally elevated U (up to 124 ppm) and Sn (up to 133 ppm); Zn and Pb contents are uniformly low (≤821 and ≤61 ppm, respectively). Varimax factor analysis of bulk compositions of these samples reveals geochemically distinct element groupings that reflect statistical associations of monazite, allanite, and xenotime; biotite and gold; detrital minerals; chalcopyrite and sparse stannite; quartz; and cobaltite with sparse selenides and tellurides. Significantly, Cu is statistically separate from Co and As

Advanced Copper Composites Against Copper-Tolerant Xanthomonas perforans and Tomato Bacterial Spot.

PubMed

Strayer-Scherer, A; Liao, Y Y; Young, M; Ritchie, L; Vallad, G E; Santra, S; Freeman, J H; Clark, D; Jones, J B; Paret, M L

2018-02-01

Bacterial spot, caused by Xanthomonas spp., is a widespread and damaging bacterial disease of tomato (Solanum lycopersicum). For disease management, growers rely on copper bactericides, which are often ineffective due to the presence of copper-tolerant Xanthomonas strains. This study evaluated the antibacterial activity of the new copper composites core-shell copper (CS-Cu), multivalent copper (MV-Cu), and fixed quaternary ammonium copper (FQ-Cu) as potential alternatives to commercially available micron-sized copper bactericides for controlling copper-tolerant Xanthomonas perforans. In vitro, metallic copper from CS-Cu and FQ-Cu at 100 μg/ml killed the copper-tolerant X. perforans strain within 1 h of exposure. In contrast, none of the micron-sized copper rates (100 to 1,000 μg/ml) from Kocide 3000 significantly reduced copper-tolerant X. perforans populations after 48 h of exposure compared with the water control (P < 0.05). All copper-based treatments killed the copper-sensitive X. perforans strain within 1 h. Greenhouse studies demonstrated that all copper composites significantly reduced bacterial spot disease severity when compared with copper-mancozeb and water controls (P < 0.05). Although there was no significant impact on yield, copper composites significantly reduced disease severity when compared with water controls, using 80% less metallic copper in comparison with copper-mancozeb in field studies (P < 0.05). This study highlights the discovery that copper composites have the potential to manage copper-tolerant X. perforans and tomato bacterial spot.

Synthesis and Cytotoxic Evaluation of Steroidal Copper (Cu (II)) Complexes

PubMed Central

Huang, Yanmin; Kong, Erbin; Zhan, Junyan; Chen, Shuang; Gan, Chunfang; Liu, Zhiping; Pang, Liping

2017-01-01

Using estrone and pregnenolone as starting materials, some steroidal copper complexes were synthesized by the condensation of steroidal ketones with thiosemicarbazide or diazanyl pyridine and then complexation of steroidal thiosemicarbazones or steroidal diazanyl pyridines with Cu (II). The complexes were characterized by IR, NMR, and HRMS. The synthesized compounds were screened for their cytotoxicity against HeLa, Bel-7404, and 293T cell lines in vitro. The results show that all steroidal copper (II) complexes display obvious antiproliferative activity against the tested cancer cells. The IC50 values of complexes 5 and 12 against Bel-7404 (human liver carcinoma) are 5.0 and 7.0 μM. PMID:29180937

[Transformation of Cu forms in Cynodon dactylon rhizosphere soil of copper tailings yard].

PubMed

Wang, You-bao; Huang, Yong-jie; Zhen, Quan; Yan, Mi; Yang, Hong-fei; Liu, Deng-yi

2007-06-01

The study on the Cu forms in Cynodon dactylon rhizosphere soil of copper tailings yard in Tongling City, Anhui Province showed that among the test Cu forms, the amount of residual form occupied the majority, while that of exchangeable form was relatively low. Compared with non-rhizosphere soil, rhizosphere soil had a higher organic matter content but a lower pH. With the growth of C. dactylon, the contents of organically combined and exchangeable Cu in rhizosphere soil increased by 7.89% and 5%, respectively, while those of carbonate-combined and Fe-Mn oxides-combined Cu decreased. The growth of C. dactylon accelerated the transformation of Cu forms in rhizosphere soil, and decreased the rhizosphere soil Cu content through its absorption.

Synthesis and characterization of hollow spherical copper phosphide (Cu 3P) nanopowders

NASA Astrophysics Data System (ADS)

Liu, Shuling; Qian, Yitai; Xu, Liqiang

2009-03-01

In this paper, hollow spherical Cu 3P nanopowders were synthesized by using copper sulfate pentahydrate (CuSO 4ṡ5H 2O) and yellow phosphorus in a mixed solvent of glycol, ethanol and water at 140-180 ∘C for 12 h. X-ray powder diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), electron diffraction pattern (ED) and transmission electronic microscopy (TEM) studies show that the as-synthesized nanocrystal is pure hexagonal phase Cu 3P with a hollow spherical morphology. Based on the TEM observations, a possible aggregation growth mechanism was proposed for the formation of Cu 3P hollow structures. Meanwhile, the effects of some key factors such as solvents, reaction temperature and reaction time on the final formation of the Cu 3P hollow structure were also discussed.

Simultaneous adsorption and degradation of Zn(2+) and Cu (2+) from wastewaters using nanoscale zero-valent iron impregnated with clays.

PubMed

Shi, Li-Na; Zhou, Yan; Chen, Zuliang; Megharaj, Mallavarapu; Naidu, Ravi

2013-06-01

Clays such as kaolin, bentonite and zeolite were evaluated as support material for nanoscale zero-valent iron (nZVI) to simultaneously remove Cu(2+) and Zn(2+) from aqueous solution. Of the three supported nZVIs, bentonite-supported nZVI (B-nZVI) was most effective in the simultaneous removal of Cu(2+) and Zn(2+) from a aqueous solution containing a 100 mg/l of Cu(2+) and Zn(2+), where 92.9 % Cu(2+) and 58.3 % Zn(2+) were removed. Scanning electronic microscope (SEM) revealed that the aggregation of nZVI decreased as the proportion of bentonite increased due to the good dispersion of nZVI, while energy dispersive spectroscopy (EDS) demonstrated the deposition of copper and zinc on B-nZVI after B-nZVI reacted with Cu(2+) and Zn(2+). A kinetics study indicated that removing Cu(2+) and Zn(2+) with B-nZVI accorded with the pseudo first-order model. These suggest that simultaneous adsorption of Cu(2+)and Zn(2+) on bentonite and the degradation of Cu(2+)and Zn(2+) by nZVI on the bentonite. However, Cu(2+) removal by B-nZVI was reduced rather than adsorption, while Zn(2+) removal was main adsorption. Finally, Cu(2+), Zn(2+), Ni(2+), Pb(2+) and total Cr from various wastewaters were removed by B-nZVI, and reusability of B-nZVI with different treatment was tested, which demonstrates that B-nZVI is a potential material for the removal of heavy metals from wastewaters.

Fe and Co nanostructures embedded into the Cu(100) surface: Self-Organization and magnetic properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kolesnikov, S. V., E-mail: kolesnikov@physics.msu.ru; Klavsyuk, A. L.; Saletsky, A. M.

The self-organization and magnetic properties of small iron and cobalt nanostructures embedded into the first layer of a Cu(100) surface are investigated using the self-learning kinetic Monte Carlo method and density functional theory. The similarities and differences between the Fe/Cu(100) and the Co/Cu(100) are underlined. The time evolution of magnetic properties of a copper monolayer with embedded magnetic atoms at 380 K is discussed.

Environmental application of millimeter-scale sponge iron (s-Fe(0)) particles (II): the effect of surface copper.

PubMed

Ju, Yongming; Liu, Xiaowen; Liu, Runlong; Li, Guohua; Wang, Xiaoyan; Yang, Yanyan; Wei, Dongyang; Fang, Jiande; Dionysiou, Dionysios D

2015-04-28

To enhance the catalytic reactivity of millimeter-scale particles of sponge iron (s-Fe(0)), Cu(2+) ions were deposited on the surface of s-Fe(0) using a simple direct reduction reaction, and the catalytic properties of the bimetallic system was tested for removal of rhodamine B (RhB) from an aqueous solution. The influence of Cu(0) loading, catalyst dosage, particle size, initial RhB concentration, and initial pH were investigated, and the recyclability of the catalyst was also assessed. The results demonstrate that the 3∼5 millimeter s-Fe(0) particles (s-Fe(0)(3∼5mm)) with 5wt% Cu loading gave the best results. The removal of RhB followed two-step, pseudo-first-order reaction kinetics. Cu(0)-s-Fe(0) showed excellent stability after five reuse cycles. Cu(0)-s-Fe(0) possesses great advantages compared to nanoscale zero-valent iron, iron power, and iron flakes as well as its bimetals. The surface Cu(0) apparently catalyzes the production of reactive hydrogen atoms for indirect reaction and generates Fe-Cu galvanic cells that enhance electron transfer for direct reaction. This bimetallic catalyst shows great potential for the pre-treatment of recalcitrant wastewaters. Additionally, some oxides containing iron element are selected to simulate the adsorption process. The results prove that the adsorption process of FeOOH, Fe2O3 and Fe3O4 played minor role for the removal of RhB. Copyright © 2015 Elsevier B.V. All rights reserved.

Acute and subacute response of iron, zinc, copper and selenium in pigs experimentally infected with Actinobacillus pleuropneumoniae.

PubMed

Humann-Ziehank, Esther; Menzel, Anne; Roehrig, Petra; Schwert, Barbara; Ganter, Martin; Hennig-Pauka, Isabel

2014-10-01

This study was performed to characterise the response of iron (Fe), zinc (Zn), copper (Cu) and selenium (Se) in bacterial-induced porcine acute phase reaction (APR). Twenty piglets were challenged by aerosolic infection with Actinobacillus pleuropneumoniae (A.pp.) serotype 2, ten piglets serving as controls. Blood sampling was done initially and at day 4 and 21 after infection, collection of liver tissue was done at day 21 (autopsy). A.pp.-infection caused fever and respiratory symptoms. APR at day 4 after infection was marked by an increase in total white blood cells, granulocytes and monocytes in whole blood samples and an increase in globulin/albumin ratio (G/A), α2-globulins, C-reactive protein, haptoglobin, ceruloplasmin (Cp), Cu and Se in serum. Concurrently, there was a decrease in haemoglobin (Hb) and packed cell volume (PCV) in whole blood as well as a decrease in albumin, transferrin, total iron binding capacity and Fe in serum and Zn in plasma. The subacute stage at day 21 was characterised by progressively increased concentrations of G/A, β-globulins and γ-globulins reflecting the specific immune reaction. Hb and PCV showed further decreases, all other parameters returned to the initial concentrations. Glutathione peroxidase activity in plasma and liver tissue remained unaffected by A.pp.-infection. The liver concentration (day 21) of Zn was found to be higher, that of Se was lower in the A.pp.-group, whereas hepatic concentrations of Cu and Fe were not affected by A.pp.-infection. In summary, the acute and subacute stages of A.pp.-infection were accurately characterised by the APR-related parameters. Se was only marginally affected by the A.pp.-infection. The elevated plasma Cu concentration may be a side effect of the transient hepatic induction of Cp synthesis. Zn responded, being distinctly reduced in plasma and probably having been sequestered in the liver tissue. Reduction in serum Fe can be regarded as an unspecific defence mechanism in A

Synthesis and characterization of Copper/Cobalt/Copper/Iron nanostructurated films with magnetoresistive properties

NASA Astrophysics Data System (ADS)

Ciupinǎ, Victor; Prioteasa, Iulian; Ilie, Daniela; Manu, Radu; Petrǎşescu, Lucian; Tutun, Ştefan Gabriel; Dincǎ, Paul; MustaÅ£ǎ, Ion; Lungu, Cristian Petricǎ; Jepu, IonuÅ£; Vasile, Eugeniu; Nicolescu, Virginia; Vladoiu, Rodica

2017-02-01

Copper/Cobalt/Copper/Iron thin films were synthesized in order to obtain nanostructured materials with special magnetoresistive properties. The multilayer films were deposited on silicon substrates. In this respect we used Thermionic Vacuum Arc Discharge Method (TVA). The benefit of this deposition technique is the ability to have a controlled range of thicknesses starting from few nanometers to hundreds of nanometers. The purity of the thin films was insured by a high vacuum pressure and a lack of any kind of buffer gas inside the coating chamber. The morphology and structure of the thin films were analyzed using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) Techniques and Energy Dispersive X-ray Spectroscopy (EDXS). Magnetoresistive measurement results depict that thin films possess Giant Magneto-Resistance Effect (GMR). Magneto-Optic-Kerr Effect (MOKE) studies were performed to characterize the magnetic properties of these thin films.

Copper uptake and retention in liver parenchymal cells isolated from nutritionally copper-deficient rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van den Berg, G.J.; de Goeij, J.J.; Bock, I.

1991-08-01

Copper uptake and retention were studied in primary cultures of liver parenchymal cells isolated from copper-deficient rats. Male Sprague-Dawley rats were fed a copper-deficient diet (less than 1 mg Cu/kg) for 10 wk. Copper-deficient rats were characterized by low copper concentrations in plasma and liver, anemia, low plasma ceruloplasmin oxidase activity and increased 64Cu whole-body retention. Freshly isolated liver parenchymal cells from copper-deficient rats showed a higher 64Cu influx, which was associated with a higher apparent Vmax of 45 {plus minus} 4 pmol Cu.mg protein-1.min-1 as compared with 30 {plus minus} 3 pmol Cu.mg protein-1.min-1 for cells isolated from copper-sufficientmore » rats. No significant difference in the apparent Km (approximately 30 mumol/L) was observed. Relative 64Cu efflux from cells from copper-deficient rats was significantly smaller than the efflux from cells from copper-sufficient rats after prelabeling as determined by 2-h efflux experiments. Analysis of the medium after efflux from cells from copper-deficient rats showed elevated protein-associated 64Cu, suggesting a higher incorporation of radioactive copper during metalloprotein synthesis. Effects of copper deficiency persist in primary cultures of parenchymal cells derived from copper-deficient rats, and short-term cultures of these cells offer a prospect for the study of cell biological aspects of the metabolic adaptation of the liver to copper deficiency.« less

Copper-resistant bacteria enhance plant growth and copper phytoextraction.

PubMed

Yang, Renxiu; Luo, Chunling; Chen, Yahua; Wang, Guiping; Xu, Yue; Shen, Zhenguo

2013-01-01

In this study, we investigated the role of rhizospheric bacteria in solubilizing soil copper (Cu) and promoting plant growth. The Cu-resistant bacterium DGS6 was isolated from a natural Cu-contaminated soil and was identified as Pseudomonas sp. DGS6. This isolate solubilized Cu in Cu-contaminated soil and stimulated root elongation of maize and sunflower. Maize was more sensitive to inoculation with DGS6 than was sunflower and exhibited greater root elongation. In pot experiment, inoculation with DGS6 increased the shoot dry weight of maize by 49% and sunflower by 34%, and increased the root dry weight of maize by 85% and sunflower by 45%. Although the concentrations of Cu in inoculated and non-inoculated seedlings did not differ significantly, the total accumulation of Cu in the plants increased after inoculation. DGS6 showed a high ability to solubilize P and produce iron-chelating siderophores, as well as significantly improved the accumulation of P and Fe in both maize and sunflower shoots. In addition, DGS6 produced indole-3-acetic acid (IAA) and ACC deaminase, which suggests that it may modulate ethylene levels in plants. The bacterial strain DGS6 could be a good candidate for re-vegetation of Cu-contaminated sites. Supplemental materials are available for this article. Go to the publisher's online edition of International Journal of Phytoremediation to view the supplemental file.

New Cu(TiBN x ) copper alloy films for industrial applications

NASA Astrophysics Data System (ADS)

Lin, Chon-Hsin

2016-06-01

In this study, I explore a new type of copper alloy, Cu(TiBN x ), films by cosputtering Cu and TiB within an Ar/N2 gas atmosphere on Si substrates. The films are then annealed for 1 h in a vacuum environment at temperatures up to 700 °C. The annealed films exhibit not only excellent thermal stability and low resistivity but also little leakage current and strong adhesion to the substrates while no Cu/Si interfacial interactions are apparent. Within a Sn/Cu(TiBN x )/Si structure at 200 °C, the new alloy exhibits a minute dissolution rate, which is lower than that of pure Cu by at least one order of magnitude. Furthermore, the new alloy’s consumption rate is comparable to that of Ni commonly used in solder joints. The new films appear suitable for some industrial applications, such as barrierless Si metallization and new wetting and diffusion barrier layers required in flip-chip solder joints.

Effect of ultrasound on the dissolution of copper from copper converter slag by acid leaching.

PubMed

Beşe, Ayşe Vildan

2007-09-01

This work presents the optimum conditions of dissolution of copper in copper converter slag in sulphuric acid ferric sulphate mixtures in the presence and absence of ultrasound. The Taguchi method was used to determine the optimum conditions. The parameters investigated were the reaction temperature, acid concentration, ferric sulphate concentration and reaction time. The optimum conditions for the maximum dissolution of copper were determined as follows: reaction temperature, 65 degrees C; acid concentration, 0.2M; ferric sulphate concentration, 0.15M; reaction time 180 min. Under these conditions, extraction efficiency of copper, zinc, cobalt, and iron from slag were 89.28%, 51.32%, 69.87%, and 13.73%, respectively, in the presence of ultrasound, while they are 80.41%, 48.28%, 64.52%, and 12.16%, respectively, in the absence of ultrasound. As seen from the above results, it is clear that ultrasound enhances on the dissolution of Cu, Zn, Co and Fe in the slag.

Trace Element Status (Zinc, Copper, Selenium, Iron, Manganese) in Patients with Long-Term Home Parenteral Nutrition.

PubMed

Dastych, Milan; Šenkyřík, Michal; Dastych, Milan; Novák, František; Wohl, Petr; Maňák, Jan; Kohout, Pavel

2016-01-01

The objective of the present study was to determine concentrations of zinc (Zn), copper (Cu), iron (Fe), selenium (Se) in blood plasma and manganese (Mn) in the whole blood in patients with long-term home parenteral nutrition (HPN) in comparison to the control group. We examined 68 patients (16 men and 52 women) aged from 28 to 68 years on a long-term HPN lasting from 4 to 96 months. The short bowel syndrome was an indication for HPN. The daily doses of Zn, Cu, Fe, Se and Mn in the last 3 months were determined. No significant differences in blood plasma were found for Zn, Cu and Fe in patients with HPN and in the control group (p > 0.05). The concentration of Mn in whole blood was significantly increased in HPN patients (p < 0.0001), while Se concentration in these patients was significantly decreased (p < 0.005). The concentration of Mn in the whole blood of 16 patients with cholestasis was significantly increased compared to the patients without cholestasis (p < 0.001). The Cu concentration was increased with no statistical significance. In long-term HPN, the status of trace elements in the patients has to be continually monitored and the daily substitution doses of these elements have to be flexibly adjusted. Dosing schedule needs to be adjusted especially in cases of cholestatic hepatopathy. A discussion about the optimal daily dose of Mn in patients on HPN is appropriate. For clinical practice, the availability of a substitution mixture of trace elements lacking Mn would be advantageous. © 2016 S. Karger AG, Basel.

Protection of Advanced Copper Alloys With Lean Cu-Cr Coatings

NASA Technical Reports Server (NTRS)

Greenbauer-Seng, L. (Technical Monitor); Thomas-Ogbuji, L.

2003-01-01

Advanced copper alloys are used as liners of rocket thrusters and nozzle ramps to ensure dissipation of the high thermal load generated during launch, and Cr-lean coatings are preferred for the protection of these liners from the aggressive ambient environment. It is shown that adequate protection can be achieved with thin Cu-Cr coatings containing as little as 17 percent Cr.

Status of neurocognitive and oxidative stress conditions in iron-steel workers.

PubMed

Malekirad, Ali Akbar; Mirabdollahi, Mansuoreh; Pilehvarian, Ali Asghar; Nassajpour, Ali Reza; Abdollahi, Mohammad

2015-07-01

The aim of this study was to determine oxidative stress status as well as ferrous (Fe) and Copper (Cu) levels in blood, neurocognitive impairment, and clinical markers in iron-steel workers. A comparative cross-sectional analysis was performed in 50 iron-steel workers who have been in contact with Fe and Cu in comparison with a control group containing 50 healthy subjects in the same age group and sex. Blood levels of lipid peroxidation, total antioxidant capacity, Fe, and Cu along with neurocognitive impairment were measured in workers and controls. Clinical examination was accomplished to record any abnormal sign or symptoms. Comparing with controls, the workers showed higher blood levels of lipid peroxidation and Cu and also a lower total antioxidant capacity. There was a positive correlation between work history and interstitial lung disease that strengths the presumption to progress to chronic obstructive lung disease in future. The results indicate that exposure to a combination of Fe and Cu in iron-steel workers induces oxidative stress. Especially, in the present case, toxic effect of Cu has been more than positive effects of Fe, but the combined exposure resulted in no such critical toxicity. © The Author(s) 2013.

Distinct oxidative cleavage and modification of bovine [Cu-Zn]-SOD by an ascorbic acid/Cu(II) system: Identification of novel copper binding site on SOD molecule

PubMed Central

Uehara, Hiroshi; Luo, Shen; Aryal, Baikuntha; Levine, Rodney L.; Rao, V. Ashutosh

2016-01-01

We investigated the combined effect of ascorbate and copper [Asc/Cu(II)] on the integrity of bovine [Cu-Zn]-superoxide dismutase (bSOD1) as a model system to study the metal catalyzed oxidation (MCO) and fragmentation of proteins. We found Asc/Cu(II) mediates specific cleavage of bSOD1 and generates 12.5 and 3.2 kDa fragments in addition to oxidation/carbonylation of the protein. The effect of other tested transition metals, a metal chelator, and hydrogen peroxide on the cleavage and oxidation indicated that binding of copper to a previously unknown site on SOD1 is responsible for the Asc/Cu(II) specific cleavage and oxidation. We utilized tandem mass spectrometry to identify the specific cleavage sites of Asc/Cu(II)-treated bSOD1. Analyses of tryptic- and AspN-peptides have demonstrated the cleavage to occur at Gly31 with peptide bond breakage with Thr30 and Ser32 through diamide and α-amidation pathways, respectively. The three-dimensional structure of bSOD1 reveals the imidazole ring of His19 localized within 5 Angstrom from the α-carbon of Gly31 providing a structural basis that copper ion, most likely coordinated by His19, catalyzes the specific cleavage reaction. PMID:26872685

Distinct oxidative cleavage and modification of bovine [Cu- Zn]-SOD by an ascorbic acid/Cu(II) system: Identification of novel copper binding site on SOD molecule.

PubMed

Uehara, Hiroshi; Luo, Shen; Aryal, Baikuntha; Levine, Rodney L; Rao, V Ashutosh

2016-05-01

We investigated the combined effect of ascorbate and copper [Asc/Cu(II)] on the integrity of bovine [Cu-Zn]-superoxide dismutase (bSOD1) as a model system to study the metal catalyzed oxidation (MCO) and fragmentation of proteins. We found Asc/Cu(II) mediates specific cleavage of bSOD1 and generates 12.5 and 3.2kDa fragments in addition to oxidation/carbonylation of the protein. The effect of other tested transition metals, a metal chelator, and hydrogen peroxide on the cleavage and oxidation indicated that binding of copper to a previously unknown site on SOD1 is responsible for the Asc/Cu(II) specific cleavage and oxidation. We utilized tandem mass spectrometry to identify the specific cleavage sites of Asc/Cu(II)-treated bSOD1. Analyses of tryptic- and AspN-peptides have demonstrated the cleavage to occur at Gly31 with peptide bond breakage with Thr30 and Ser32 through diamide and α-amidation pathways, respectively. The three-dimensional structure of bSOD1 reveals the imidazole ring of His19 localized within 5Å from the α-carbon of Gly31 providing a structural basis that copper ion, most likely coordinated by His19, catalyzes the specific cleavage reaction. Published by Elsevier Inc.

Influence of iron and copper oxides on polychlorinated diphenyl ether formation in heterogeneous reactions.

PubMed

Liu, Wenxia; Shen, Lianfeng; Zhang, Fawen; Liu, Wenbin; Zheng, Minghui; Yang, Xitian

2013-08-01

Polychlorinated diphenyl ether (PCDE) has attracted great attention recently as an important type of environmental pollutant. The influence of iron and copper oxides on formation of PCDEs was investigated using laboratory-scale flow reactors under air and under nitrogen at 350 °C, a temperature corresponding to the post-combustion zone of a municipal solid waste incinerator. The results show that the 2,2',3,4,4',5,5',6-otachlorodiphenyl ether (OCDE) formed from the condensation of pentachlorophenol (PCP) and 1,2,4,5-tetrachlorobenzene (Cl4Bz) is the predominant congener formed on the SiO2/Fe2O3 surface with and without oxygen. This indicated that HCl elimination between PCP and 1,2,4,5-Cl4Bz molecules formed 2,2',3,4,4',5,5',6-OCDE in the presence of Fe2O3. On the other hand, decachlorodiphenyl ether, nonachlorodiphenyl ether, and OCDE were the dominant products on the SiO2/CuO surface without oxygen, although the 2,2',3,4,4',5,5',6-OCDE was the dominant product on the SiO2/CuO surface with oxygen. Therefore, the presence of Fe2O3 and CuO influences the formation and homologue distribution of PCDEs, which shifted towards the lower chlorinated species. Fe2O3 can promote both the condensation and dechlorination reaction without oxygen. On the contrary, with oxygen, Fe2O3 suppresses the condensation of chlorobenzene and chlorophenol to form PCDEs and polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). CuO can increase the formation of lower chlorinated PCDEs and PCDDs without oxygen. In conclusion, the different fly ash components have a major influence on PCDE emissions.

Beer improves copper metabolism and increases longevity in Cu-deficient rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moore, R.J.; Klevay, L.M.

Moderate consumption of alcoholic beverages decreases risk of death from ischemic heart disease (IHD). Evidence suggests that Cu-deficiency is important in the etiology and pathophysiology of IHD. The effect of beer (25 ng Cu/ml) drinking on the severity of Cu-deficiency was examined in weanling, male Sprague-Dawley rats fed a low Cu diet (0.84 {mu}g Cu/g). Beer drinking increased median longevity to 204 or 299 d from 62 or 42 d respectively in rats drinking water in two experiments (15 rats/group). In experiment 3, a single dose of {sup 67}Cu (3.3 {mu}Ci as chloride) was added to 1 g of feedmore » and given to 12-h fasted rats 30 d after the start of the experiment. Whole body counting over 13 d showed apparent Cu absorption and t{sub {1/2}} (biological) were greater in Cu-deficient rats drinking beer than in similar rats drinking water. Plasma cholesterol was lower but hematocrit and liver Cu were higher in surviving rats drinking beer than in rats drinking water. Body weight was not affected by beer in any experiment. In experiment 4, a 4% aqueous ethanol solution had no effect on longevity of copper deficient rats. A non-alcohol component of beer alters Cu metabolism and mitigates the severity of nutritional Cu-deficiency in rats.« less

"Twin copper source" growth of metal-organic framework membrane: Cu(3)(BTC)(2) with high permeability and selectivity for recycling H(2).

PubMed

Guo, Hailing; Zhu, Guangshan; Hewitt, Ian J; Qiu, Shilun

2009-02-11

In this communication, the copper net supported Cu(3)(BTC)(2) membranes have been successfully synthesized by means of a "twin copper source" technique. Separation studies on gaseous mixtures (H(2)/CO(2), H(2)/CH(4), and H(2)/N(2)) using the membrane revealed that the membrane possesses high permeability and selectivity for H(2) over CO(2), N(2), and CH(4). Compared with the conventional zeolite membranes, the copper net supported Cu(3)(BTC)(2) membrane exhibited high permeation flux in gas separation. Such highly efficient copper net supported Cu(3)(BTC)(2) membranes could be used to separate, recycle, and reuse H(2) exhausted from steam reforming natural gas.

The role of insufficient copper in lipid synthesis and fatty-liver disease.

PubMed

Morrell, Austin; Tallino, Savannah; Yu, Lei; Burkhead, Jason L

2017-04-01

The essential transition metal copper is important in lipid metabolism, redox balance, iron mobilization, and many other critical processes in eukaryotic organisms. Genetic diseases where copper homeostasis is disrupted, including Menkes disease and Wilson disease, indicate the importance of copper balance to human health. The severe consequences of insufficient copper supply are illustrated by Menkes disease, caused by mutation in the X-linked ATP7A gene encoding a protein that transports copper from intestinal epithelia into the bloodstream and across the blood-brain barrier. Inadequate copper supply to the body due to poor diet quality or malabsorption can disrupt several molecular level pathways and processes. Though much of the copper distribution machinery has been described and consequences of disrupted copper handling have been characterized in human disease as well as animal models, physiological consequences of sub-optimal copper due to poor nutrition or malabsorption have not been extensively studied. Recent work indicates that insufficient copper may be important in a number of common diseases including obesity, ischemic heart disease, and metabolic syndrome. Specifically, marginal copper deficiency (CuD) has been reported as a potential etiologic factor in diseases characterized by disrupted lipid metabolism such as non-alcoholic fatty-liver disease (NAFLD). In this review, we discuss the available data suggesting that a significant portion of the North American population may consume insufficient copper, the potential mechanisms by which CuD may promote lipid biosynthesis, and the interaction between CuD and dietary fructose in the etiology of NAFLD. © 2016 IUBMB Life, 69(4):263-270, 2017. © 2017 International Union of Biochemistry and Molecular Biology.

Serum copper concentration as an index of clinical lung injury

DOE Office of Scientific and Technical Information (OSTI.GOV)

Molteni, A.; Ward, W.F.; Kim, Y.T.

1989-01-01

The purpose of this ongoing study is to determine whether thoracic radiotherapy for lung cancer produces an early increase in serum copper (Cu) concentration, an increase which might predict clinical outcome. Copper and iron concentrations were measured in serum obtained from nonsmall cell lung cancer patients at 0, 1, 2, 4, and 6 weeks after the start of radiotherapy. Control groups included patients irradiated for breast cancer (low dose of radiation to the lung), for endometrial, cervical or prostatic cancer, and patients with congestive heart failure, pulmonary hypertension, chronic obstructive pulmonary disease (COPD), and cutaneous burns with or without smokemore » inhalation. Serum Cu concentration increased at least 10 micrograms/dl from the pretreatment level in approximately 75% of the adenocarcinoma and squamous cell lung cancer patients, but in only 1 of 4 undifferentiated lung cancer cases. In virtually all of these responders, serum Cu increased to a maximum at 2 weeks after the start of therapy, then plateaued or decreased slightly despite continuing irradiation. Within the subset of squamous cell lung cancers, there was a direct correlation between the degree of histologic differentiation and both baseline serum Cu concentration and the probability of an early increase therein. In contrast, only 33% of breast cancer patients and 15% of endometrial, cervical and prostate cancer patients exhibited an increase in serum Cu concentration at 2 weeks after the start of radiotherapy. Serum Cu concentration was within normal limits in virtually all patients with congestive heart failure, pulmonary hypertension, and COPD. Burn patients exhibited a significant reduction in serum Cu, although concomitant smoke inhalation increased serum Cu back to low-normal levels. Serum iron concentration did not change significantly in any category of patients.« less

Spectroscopy of Cu(II)-PcoC and the multicopper oxidase function of PcoA, two essential components of Escherichia coli pco copper resistance operon.

PubMed

Huffman, David L; Huyett, Jennifer; Outten, F Wayne; Doan, Peter E; Finney, Lydia A; Hoffman, Brian M; O'Halloran, Thomas V

2002-08-06

The plasmid-encoded pco copper resistance operon in Escherichia coli consists of seven genes that are expressed from two pco promoters in response to elevated copper; however, little is known about how they mediate resistance to excess environmental copper. Two of the genes encode the soluble periplasmic proteins PcoA and PcoC. We show here that inactivation of PcoC, and PcoA to a lesser extent, causes cells to become more sensitive to copper than wild-type nonresistant strains, consistent with a tightly coupled detoxification pathway. Periplasmic extracts show copper-inducible oxidase activity, attributed to the multicopper oxidase function of PcoA. PcoC, a much smaller protein than PcoA, binds one Cu(II) and exhibits a weak electronic transition characteristic of a type II copper center. ENDOR and ESEEM spectroscopy of Cu(II)-PcoC and the (15)N- and Met-CD(3)-labeled samples are consistent with a tetragonal ligand environment of three nitrogens and one aqua ligand "in the plane". A weakly associated S-Met and aqua are likely axial ligands. At least one N is a histidine and is likely trans to the in-plane aqua ligand. The copper chemistry of PcoC and the oxidase function of PcoA are consistent with the emerging picture of the chromosomally encoded copper homeostasis apparatus in the E. coli cell envelope [Outten, F. W., Huffman, D. L., Hale, J. A., and O'Halloran, T. V. (2001) J. Biol. Chem. 276, 30670-30677]. We propose a model for the plasmid system in which Cu(I)-PcoC functions in this copper efflux pathway as a periplasmic copper binding protein that docks with the multiple repeats of Met-rich domains in PcoA to effect oxidation of Cu(I) to the less toxic Cu(II) form. The solvent accessibility of the Cu(II) in PcoC may allow for metal transfer to other plasmid and chromosomal factors and thus facilitate removal of Cu(II) from the cell envelope.

Activation of Cu,Zn-superoxide dismutase in the absence of oxygen and the copper chaperone CCS.

PubMed

Leitch, Jeffry M; Jensen, Laran T; Bouldin, Samantha D; Outten, Caryn E; Hart, P John; Culotta, Valeria C

2009-08-14

Eukaryotic Cu,Zn-superoxide dismutases (SOD1s) are generally thought to acquire the essential copper cofactor and intramolecular disulfide bond through the action of the CCS copper chaperone. However, several metazoan SOD1s have been shown to acquire activity in vivo in the absence of CCS, and the Cu,Zn-SOD from Caenorhabditis elegans has evolved complete independence from CCS. To investigate SOD1 activation in the absence of CCS, we compared and contrasted the CCS-independent activation of C. elegans and human SOD1 to the strict CCS-dependent activation of Saccharomyces cerevisiae SOD1. Using a yeast expression system, both pathways were seen to acquire copper derived from cell surface transporters and compete for the same intracellular pool of copper. Like CCS, CCS-independent activation occurs rapidly with a preexisting pool of apo-SOD1 without the need for new protein synthesis. The two pathways, however, strongly diverge when assayed for the SOD1 disulfide. SOD1 molecules that are activated without CCS exhibit disulfide oxidation in vivo without oxygen and under copper-depleted conditions. The strict requirement for copper, oxygen, and CCS in disulfide bond oxidation appears exclusive to yeast SOD1, and we find that a unique proline at position 144 in yeast SOD1 is responsible for this disulfide effect. CCS-dependent and -independent pathways also exhibit differential requirements for molecular oxygen. CCS activation of SOD1 requires oxygen, whereas the CCS-independent pathway is able to activate SOD1s even under anaerobic conditions. In this manner, Cu,Zn-SOD from metazoans may retain activity over a wide range of physiological oxygen tensions.

Thermoelectric transport in Cu7PSe6 with high copper ionic mobility.

PubMed

Weldert, Kai S; Zeier, Wolfgang G; Day, Tristan W; Panthöfer, Martin; Snyder, G Jeffrey; Tremel, Wolfgang

2014-08-27

Building on the good thermoelectric performances of binary superionic compounds like Cu2Se, Ag2Se and Cu2S, a better and more detailed understanding of phonon-liquid electron-crystal (PLEC) thermoelectric materials is desirable. In this work we present the thermoelectric transport properties of the compound Cu7PSe6 as the first representative of the class of argyrodite-type ion conducting thermoelectrics. With a huge variety of possible compositions and high ionic conductivity even at room temperature, the argyrodites represent a very good model system to study structure-property relationships for PLEC thermoelectric materials. We particularly highlight the extraordinary low thermal conductivity of Cu7PSe6 below the glass limit, which can be associated with the molten copper sublattice leading to a softening of phonon modes.

Tunneling electron induced chemisorption of copper phthalocyanine molecules on the Cu(111) surface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stock, T.; Nogami, J.

2014-02-17

The adsorption of up to one monolayer (ML) of copper phthalocyanine (CuPc) molecules on a room temperature Cu(111) surface has been studied using scanning tunneling microscopy (STM). Below 1 ML the molecules are in a fluid state and are highly mobile on the surface. At 1 ML coverage the molecules coalesce into a highly ordered 2D crystal phase. At sub-ML coverages, chemisorption of individual CuPc molecules can be induced through exposure to tunneling electrons at a tunneling bias voltage exceeding a threshold value. This tunneling electron induced effect has been exploited to perform molecular STM lithography.

Properties and characterization of agar/CuNP bionanocomposite films prepared with different copper salts and reducing agents.

PubMed

Shankar, Shiv; Teng, Xinnan; Rhim, Jong-Whan

2014-12-19

Various types of agar-based bio-nanocomposite (BNC) films were prepared by blending agar and six different copper nanoparticles (CuNPs) with different shapes and sizes obtained from three different sources of copper salts and two different reducing agents. The BNC films were characterized by UV-visible, FE-SEM, FT-IR, and XRD. The thermogravimetric study showed that the melting point of BNC films was increased when ascorbic acid was used as a reducing agent for CuNPs synthesis. Apparent surface color and transmittance of agar film was greatly influenced by the reinforcement of CuNPs. However, mechanical and water vapor barrier properties did not change significantly (p>0.05) by blending with CuNPs. Tensile modulus and tensile strength decreased slightly for all types of CuNPs reinforced while elongation at break slightly increased when CuNPs produced by ascorbic acid were blended. The agar bio-nanocomposite films showed profound antibacterial activity against both Gram-positive and Gram-negative food-borne pathogenic bacteria. Copyright © 2014 Elsevier Ltd. All rights reserved.

Copper, zinc, gallium and germanium distributions in taenite lamellae of iron meteorites and their importance for cooling rate estimations

NASA Astrophysics Data System (ADS)

Braun-Dullaeus, Karl-Ulrich; Traxel, Kurt

1995-02-01

One method forestimating cooling rates of meteorite parent bodies is to model measured nickel distributions in taenite lamellae of iron meteorites. Goldstein and Ogilvie ( Geochim. Cosmochim. Acta29, 893, 1965) and Rasmussen ( Icarus45, 564, 1981) developed techniques based on this idea to examine the cooling history in the temperature range between ˜700 and ˜400°C. As a result of Instrumental Neutron Activation Analysis (INAA) Rasmussen et al. ( Meteoritics23, 105, 1988) postulated that some trace elements would also be good cooling rate indicators. They argued that elements with distinct diffusion behavior are sensitive to different temperature ranges. The new Heidelberg proton microprobe uses the method of Proton Induced X-ray Emission (PIXE) for elemental analysis. This microprobe is an appropriate instrument to measure distributions of trace elements with a spatial resolution of 2 μm. We demonstrated on the iron meteorites Cape York (Agpalilik), Toluca and Odessa that the elements copper, zinc, gallium and germanium imitate the profiles of nickel in taenite lamella. The interpretation of the Zn, Ga and Ge profiles leads to the conclusion that these elements undergo diffusion mechanisms comparable to those of Ni. The numerical simulation of Cu distributions with a simplified model points out that little new information can be obtained about the cooling history of the meteorites by modelling Cu profiles. To simulate Zn, Ga or Ge distributions, the use of ternary phase diagrams is necessary.

Reference correlations for the thermal conductivity of liquid copper, gallium, indium, iron, lead, nickel and tin**

PubMed Central

Assael, Marc J.; Chatzimichailidis, Arsenios; Antoniadis, Konstantinos D.; Wakeham, William A.; Huber, Marcia L.; Fukuyama, Hiroyuki

2017-01-01

The available experimental data for the thermal conductivity of liquid copper, gallium, indium, iron, lead, nickel, and tin has been critically examined with the intention of establishing thermal conductivity reference correlations. All experimental data have been categorized into primary and secondary data according to the quality of measurement specified by a series of criteria. The proposed standard reference correlations for the thermal conductivity of liquid copper, gallium, indium, iron, lead, nickel, and tin are respectively characterized by uncertainties of 9.8, 15.9, 9.7, 13.7, 16.9, 7.7, and 12.6% at the 95% confidence level. PMID:29353915

Amendments promote the development of Lolium perenne in soils affected by historical copper smelting operations.

PubMed

Goecke, Paul; Ginocchio, Rosanna; Mench, Michel; Neaman, Alexander

2011-07-01

The Puchuncaví valley, central Chile, has been exposed to aerial emissions from a copper smelter. Nowadays, soils in the surroundings are sparsely-vegetated, acidic, and metal-contaminated, and their remediation is needed to reduce environmental risks. We assessed effectiveness of lime, fly ash, compost, and iron grit as amendments to immobilize Cu in soils and promote plant growth. Amended soils were cultivated with Lolium perenne for 60 days under controlled conditions. Total dissolved Cu and Cu2+ activity in the soil solution, ryegrass biomass, and Cu accumulation in plant tissues were measured. Addition of lime and fly ash decreased Cu concentrations and Cu2+ activity in the soil solution, increased plant biomass, and reduced shoot Cu concentration below 22 mg kg(-1) (the phytotoxicity threshold for the species). The most effective amendment with respect to the shoot biomass yield was a combination of lime and compost. Water content of the substrate and the K accumulation were positively correlated with the compost application rate. Compost combined with iron grit decreased dissolved Cu concentrations during the period of highest solubility, i.e., during the first 60 days after the compost application. However, iron grit incorporation into soils amended with lime and compost decreased the shoot biomass of ryegrass.

VAPOR PHASE MERCURY SORPTION BY ORGANIC SULFIDE MODIFIED BIMETALLIC IRON-COPPER NANOPARTICLE AGGREGATES

EPA Science Inventory

Novel organic sulfide modified bimetallic iron-copper nanoparticle aggregate sorbent materials have been synthesized for removing elemental mercury from vapor streams at elevated temperatures (120-140 °C). Silane based (disulfide silane and tetrasulfide silane) and alkyl sulfide ...

Copper Efflux Is Induced during Anaerobic Amino Acid Limitation in Escherichia coli To Protect Iron-Sulfur Cluster Enzymes and Biogenesis

PubMed Central

Fung, Danny Ka Chun; Lau, Wai Yin; Chan, Wing Tat

2013-01-01

Adaptation to changing environments is essential to bacterial physiology. Here we report a unique role of the copper homeostasis system in adapting Escherichia coli to its host-relevant environment of anaerobiosis coupled with amino acid limitation. We found that expression of the copper/silver efflux pump CusCFBA was significantly upregulated during anaerobic amino acid limitation in E. coli without the supplement of exogenous copper. Inductively coupled plasma mass spectrometry analysis of the total intracellular copper content combined with transcriptional assay of the PcusC-lacZ reporter in the presence of specific Cu(I) chelators indicated that anaerobic amino acid limitation led to the accumulation of free Cu(I) in the periplasmic space of E. coli, resulting in Cu(I) toxicity. Cells lacking cusCFBA and another copper transporter, copA, under this condition displayed growth defects and reduced ATP production during fumarate respiration. Ectopic expression of the Fe-S cluster enzyme fumarate reductase (Frd), or supplementation with amino acids whose biosynthesis involves Fe-S cluster enzymes, rescued the poor growth of ΔcusC cells. Yet, Cu(I) treatment did not impair the Frd activity in vitro. Further studies revealed that the alternative Fe-S cluster biogenesis system Suf was induced during the anaerobic amino acid limitation, and ΔcusC enhanced this upregulation, indicating the impairment of the Fe-S cluster assembly machinery and the increased Fe-S cluster demands under this condition. Taken together, we conclude that the copper efflux system CusCFBA is induced during anaerobic amino acid limitation to protect Fe-S cluster enzymes and biogenesis from the endogenously originated Cu(I) toxicity, thus facilitating the physiological adaptation of E. coli. PMID:23893112

Hydrogen bonding in basic copper salts: a spectroscopic study of malachite, Cu2(OH)2CO3, and brochantite, Cu4(OH)6SO4

NASA Astrophysics Data System (ADS)

Schmidt, M.; Lutz, H. D.

1993-05-01

Infrared and Raman spectra of the basic copper salts malachite, Cu2(OH)2CO3, and brochantite, Cu4(OH)6SO4, as well as of deuterated and 13C substituted samples are presented and discussed in terms of group theory and the hydrogen bonds present. The main results are that (i) the hydrogen donor strengths of the OH- ions are strongly increased due to the very great synergetic effect of the copper ions, (ii) the acceptor strengths of the H-bond acceptor groups (SO4 2-, CO3 2-, and OH- ions) are significantly modified by the linkage and coordination of the acceptor atoms — this complicates true assignment of the OH bands observed to the two and six different OH- ions present in malachite and brochantite, respectively -, and (iii) the Cu — O stretching modes at 430 590 cm-1 and 420 520 cm-1 for malachite and brochantite, respectively, exhibit strong, partially covalent Cu — O bonding.

Effect of copper on the properties of Pr-Dy-Fe-Co-B sintered magnets

NASA Astrophysics Data System (ADS)

Kablov, E. N.; Piskorskii, V. P.; Valeev, R. A.; Volkov, N. V.; Davydova, E. A.; Shaikhutdinov, K. A.; Balaev, D. A.; Semenov, S. V.

2014-01-01

The effect of copper on the properties of magnets (Pr0.52Dy0.48)13(Fe65Co0.35)80.3 - x Cu x B6.7 ( x = 0-10) has been studied. Alloying with copper is shown to decrease the sintering temperature and to increase the content of the principal (Pr,Dy)2(Fe,Co)14B magnetic phase. For compositions with x = 1.3-3.3, copper is found to affect the value and sign of the temperature induction coefficient (TIC). It is shown that the effect of copper on the TIC is determined by the substitution of copper ions for iron ions in lattice sites, which are coupled via an antiferromagnetic exchange interaction.

Content of total iron, copper and manganese in liver of animals during hypokinesia, muscle activity and process of recovery

NASA Technical Reports Server (NTRS)

Potapovich, G. M.; Taneyeva, G. V.; Uteshev, A. B.

1980-01-01

It is shown that the content of total iron, copper and manganese in the liver of animals is altered depending on the intensity and duration of their swimming. Hypodynamia for 7 days does not alter the concentration of iron, but sufficiently increases the content of copper and manganese. The barometric factor effectively influences the maintenance of constancy in the content of microelements accumulated in the liver after intensive muscle activity.

Cadmium, copper, iron, and zinc concentrations in kidneys of grey wolves, Canis lupus, from Alaska, Idaho, Montana (USA) and the Northwest Territories (Canada).

PubMed

Hoffmann, S R; Blunck, S A; Petersen, K N; Jones, E M; Koval, J C; Misek, R; Frick, J A; Cluff, H D; Sime, C A; McNay, M; Beckman, K B; Atkinson, M W; Drew, M; Collinge, M D; Bangs, E E; Harper, R G

2010-11-01

Cadmium, copper, iron, and zinc levels were measured in the kidneys of 115 grey wolves (Canis lupus) from Idaho, Montana and Alaska (United States), and from the Northwest Territories (Canada). No significant differences in the levels of iron or copper were observed between locations, but wolf kidneys from more northern locations had significantly higher cadmium levels (Alaska > Northwest Territories > Montana ≈ Idaho), and wolves from Alaska showed significantly higher zinc than other locations. Additionally, female wolves in Alaska had higher iron levels than males, and adult wolves in Montana had higher copper levels than subadults.

Mechanism of unintentionally produced persistent organic pollutant formation in iron ore sintering.

PubMed

Sun, Yifei; Liu, Lina; Fu, Xin; Zhu, Tianle; Buekens, Alfons; Yang, Xiaoyi; Wang, Qiang

2016-04-05

Effects of temperature, carbon content and copper additive on formation of chlorobenzenes (CBzs) and polychlorinated biphenyls (PCBs) in iron ore sintering were investigated. By heating simulated fly ash (SFA) at a temperature range of 250-500°C, the yield of both CBzs and PCBs presented two peaks of 637ng/g-fly ash at 350°C and 1.5×10(5)ng/g-fly ash at 450°C for CBzs, and 74ng/g-fly ash at 300°C and 53ng/g-fly ash at 500°C. Additionally, in the thermal treatment of real fly ash (RFA), yield of PCBs displayed two peak values at 350°C and 500°C, however, yield of CBzs showed only one peak at 400°C. In the thermal treatment of SFA with a carbon content range of 0-20wt% at 300°C, both CBzs and PCBs obtained the maximum productions of 883ng/g-fly ash for CBzs and 127ng/g-fly ash for PCBs at a 5wt% carbon content. Copper additives also affected chlorinated aromatic formation. The catalytic activity of different copper additives followed the orders: CuCl2∙2H2O>Cu2O>Cu>CuSO4>CuO for CBzs, and CuCl2∙2H2O>Cu2O>CuO>Cu>CuSO4 for PCBs. Copyright © 2015 Elsevier B.V. All rights reserved.

Activation of CuZn superoxide dismutases from Caenorhabditis elegans does not require the copper chaperone CCS.

PubMed

Jensen, Laran T; Culotta, Valeria Cizewski

2005-12-16

Reactive oxygen species are produced as the direct result of aerobic metabolism and can cause damage to DNA, proteins, and lipids. A principal defense against reactive oxygen species involves the superoxide dismutases (SOD) that act to detoxify superoxide anions. Activation of CuZn-SODs in eukaryotic cells occurs post-translationally and is generally dependent on the copper chaperone for SOD1 (CCS), which inserts the catalytic copper cofactor and catalyzes the oxidation of a conserved disulfide bond that is essential for activity. In contrast to other eukaryotes, the nematode Caenorhabditis elegans does not contain an obvious CCS homologue, and we have found that the C. elegans intracellular CuZn-SODs (wSOD-1 and wSOD-5) are not dependent on CCS for activation when expressed in Saccharomyces cerevisiae. CCS-independent activation of CuZn-SODs is not unique to C. elegans; however, this is the first organism identified that appears to exclusively use this alternative pathway. As was found for mammalian SOD1, wSOD-1 exhibits a requirement for reduced glutathione in CCS-independent activation. Unexpectedly, wSOD-1 was inactive even in the presence of CCS when glutathione was depleted. Our investigation of the cysteine residues that form the disulfide bond in wSOD-1 suggests that the ability of wSODs to readily form this disulfide bond may be the key to obtaining high levels of activation through the CCS-independent pathway. Overall, these studies demonstrate that the CuZn-SODs of C. elegans have uniquely evolved to acquire copper without the copper chaperone and this may reflect the lifestyle of this organism.

Cryptococcus neoformans Iron-Sulfur Protein Biogenesis Machinery Is a Novel Layer of Protection against Cu Stress.

PubMed

Garcia-Santamarina, Sarela; Uzarska, Marta A; Festa, Richard A; Lill, Roland; Thiele, Dennis J

2017-10-31

Copper (Cu) ions serve as catalytic cofactors to drive key biochemical processes, and yet Cu levels that exceed cellular homeostatic control capacity are toxic. The underlying mechanisms for Cu toxicity are poorly understood. During pulmonary infection by the fungal pathogen Cryptococcus neoformans , host alveolar macrophages compartmentalize Cu to the phagosome, and the ability to detoxify Cu is critical for its survival and virulence. Here, we report that iron-sulfur (Fe-S) clusters are critical targets of Cu toxicity in both Saccharomyces cerevisiae and C. neoformans in a manner that depends on the accessibility of Cu to the Fe-S cofactor. To respond to this Cu-dependent Fe-S stress, C. neoformans induces the transcription of mitochondrial ABC transporter Atm1, which functions in cytosolic-nuclear Fe-S protein biogenesis in response to Cu and in a manner dependent on the Cu metalloregulatory transcription factor Cuf1. As Atm1 functions in exporting an Fe-S precursor from the mitochondrial matrix to the cytosol, C. neoformans cells depleted for Atm1 are sensitive to Cu even while the Cu-detoxifying metallothionein proteins are highly expressed. We provide evidence for a previously unrecognized microbial defense mechanism to deal with Cu toxicity, and we highlight the importance for C. neoformans of having several distinct mechanisms for coping with Cu toxicity which together could contribute to the success of this microbe as an opportunistic human fungal pathogen. IMPORTANCE C. neoformans is an opportunistic pathogen that causes lethal meningitis in over 650,000 people annually. The severity of C. neoformans infections is further compounded by the use of toxic or poorly effective systemic antifungal agents as well as by the difficulty of diagnosis. Cu is a natural potent antimicrobial agent that is compartmentalized within the macrophage phagosome and used by innate immune cells to neutralize microbial pathogens. While the Cu detoxification machinery of C

Oxidation Mechanism of Copper Selenide

NASA Astrophysics Data System (ADS)

Taskinen, Pekka; Patana, Sonja; Kobylin, Petri; Latostenmaa, Petri

2014-09-01

The oxidation mechanism of copper selenide was investigated at deselenization temperatures of copper refining anode slimes. The isothermal roasting of synthetic, massive copper selenide in flowing oxygen and oxygen - 20% sulfur dioxide mixtures at 450-550 °C indicate that in both atmospheres the mass of Cu2Se increases as a function of time, due to formation of copper selenite as an intermediate product. Copper selenide oxidises to copper oxides without formation of thick copper selenite scales, and a significant fraction of selenium is vaporized as SeO2(g). The oxidation product scales on Cu2Se are porous which allows transport of atmospheric oxygen to the reaction zone and selenium dioxide vapor to the surrounding gas. Predominance area diagrams of the copper-selenium system, constructed for selenium roasting conditions, indicate that the stable phase of copper in a selenium roaster gas with SO2 is the sulfate CuSO4. The cuprous oxide formed in decomposition of Cu2Se is further sulfated to CuSO4.

Elementary surface chemistry during CuO/Al nanolaminate-thermite synthesis: copper and oxygen deposition on aluminum (111) surfaces.

PubMed

Lanthony, Cloé; Guiltat, Mathilde; Ducéré, Jean Marie; Verdier, Agnes; Hémeryck, Anne; Djafari-Rouhani, Mehdi; Rossi, Carole; Chabal, Yves J; Estève, Alain

2014-09-10

The surface chemistry associated with the synthesis of energetic nanolaminates controls the formation of the critical interfacial layers that dominate the performances of nanothermites. For instance, the interaction of Al with CuO films or CuO with Al films needs to be understood to optimize Al/CuO nanolaminates. To that end, the chemical mechanisms occurring during early stages of molecular CuO adsorption onto crystalline Al(111) surfaces are investigated using density functional theory (DFT) calculations, leading to the systematic determination of their reaction enthalpies and associated activation energies. We show that CuO undergoes dissociative chemisorption on Al(111) surfaces, whereby the Cu and O atoms tend to separate from each other. Both Cu and O atoms form islands with different properties. Copper islanding fosters Cu insertion (via surface site exchange mechanism) into the subsurface, while oxygen islands remain stable at the surface. Above a critical local oxygen coverage, aluminum atoms are extracted from the Al surface, leading to oxygen-aluminum intermixing and the formation of aluminum oxide (γ-alumina). For Cu and O co-deposition, copper promotes oxygen-aluminum interaction by oxygen segregation and separates the resulting oxide from the Al substrate by insertion into Al and stabilization below the oxide front, preventing full mixing of Al, Cu, and O species.

Effects of aluminum and copper chill on mechanical properties and microstructures of Cu-Zn-Al alloys with sand casting

NASA Astrophysics Data System (ADS)

Ardhyananta, Hosta; Wibisono, Alvian Toto; Ramadhani, Mavindra; Widyastuti, Farid, Muhammad; Gumilang, Muhammad Shena

2018-04-01

Cu-Zn-Al alloy is one type of brass, which has high strength and high corrosion resistant. It has been applied on ship propellers and marine equipment. In this research, the addition of aluminum (Al) with variation of 1, 2, 3, 4% aluminum to know the effect on mechanical properties and micro structure at casting process using a copper chill and without copper chill. This alloy is melted using furnace in 1100°C without holding. Then, the molten metal is poured into the mold with copper chill and without copper chill. The speciment of Cu-Zn-Al alloy were chracterized by using Optical Emission Spectroscopy (OES), Metallography Test, X-Ray Diffraction (XRD), Hardness Test of Rockwell B and Charpy Impact Test. The result is the addition of aluminum and the use of copper chill on the molds can reduce the grain size, increases the value of hardness and impact.

The Cu(II) affinity of the N-terminus of human copper transporter CTR1: Comparison of human and mouse sequences.

PubMed

Bossak, Karolina; Drew, Simon C; Stefaniak, Ewelina; Płonka, Dawid; Bonna, Arkadiusz; Bal, Wojciech

2018-05-01

Copper Transporter 1 (CTR1) is a homotrimeric membrane protein providing the main route of copper transport into eukaryotic cells from the extracellular milieu. Its N-terminal extracellular domain, rich in His and Met residues, is considered responsible for directing copper into the transmembrane channel. Most of vertebrate CTR1 proteins contain the His residue in position three from N-terminus, creating a well-known Amino Terminal Cu(II)- and Ni(II)-Binding (ATCUN) site. CTR1 from humans, primates and many other species contains the Met-Asp-His (MDH) sequence, while some rodents including mouse have the Met-Asn-His (MNH) N-terminal sequence. CTR1 is thought to collect Cu(II) ions from blood copper transport proteins, including albumin, but previous reports indicated that the affinity of N-terminal peptide/domain of CTR1 is significantly lower than that of albumin, casting serious doubt on this aspect of CTR1 function. Using potentiometry and spectroscopic techniques we demonstrated that MDH-amide, a tripeptide model of human CTR1 N-terminus, binds Cu(II) with K of 1.3 × 10 13  M -1 at pH 7.4, ~13 times stronger than Human Serum Albumin (HSA), and MNH-amide is even stronger, K of 3.2 × 10 14  M -1 at pH 7.4. These results indicate that the N-terminus of CTR1 may serve as intermediate binding site during Cu(II) transfer from blood copper carriers to the transporter. MDH-amide, but not MNH-amide also forms a low abundance complex with non-ATCUN coordination involving the Met amine, His imidazole and Asp carboxylate. This species might assist Cu(II) relay down the peptide chain or its reduction to Cu(I), both steps necessary for the CTR1 function. Copyright © 2018 Elsevier Inc. All rights reserved.

The effect of copper(II), iron(II) sulphate, and vitamin C combinations on the weak antimicrobial activity of (+)-catechin against Staphylococcus aureus and other microbes.

PubMed

Holloway, Andrew C; Mueller-Harvey, Irene; Gould, Simon W J; Fielder, Mark D; Naughton, Declan P; Kelly, Alison F

2012-12-01

Few attempts have been made to improve the activity of plant compounds with low antimicrobial efficacy. (+)-Catechin, a weak antimicrobial tea flavanol, was combined with putative adjuncts and tested against different species of bacteria. Copper(II) sulphate enhanced (+)-catechin activity against Pseudomonas aeruginosa but not Staphylococcus aureus, Proteus mirabilis or Escherichia coli. Attempts to raise the activity of (+)-catechin against two unresponsive species, S. aureus and E. coli, with iron(II) sulphate, iron(III) chloride, and vitamin C, showed that iron(II) enhanced (+)-catechin against S. aureus, but not E. coli; neither iron(III) nor combined iron(II) and copper(II), enhanced (+)-catechin activity against either species. Vitamin C enhanced copper(II) containing combinations against both species in the absence of iron(II). Catalase or EDTA added to active samples removed viability effects suggesting that active mixtures had produced H(2)O(2)via the action of added metal(II) ions. H(2)O(2) generation by (+)-catechin plus copper(II) mixtures and copper(II) alone could account for the principal effect of bacterial growth inhibition following 30 minute exposures as well as the antimicrobial effect of (+)-catechin-iron(II) against S. aureus. These novel findings about a weak antimicrobial flavanol contrast with previous knowledge of more active flavanols with transition metal combinations. Weak antimicrobial compounds like (+)-catechin within enhancement mixtures may therefore be used as efficacious agents. (+)-Catechin may provide a means of lowering copper(II) or iron(II) contents in certain crop protection and other products.

Detection of increased 64Cu uptake by human copper transporter 1 gene overexpression using PET with 64CuCl2 in human breast cancer xenograft model.

PubMed

Kim, Kwang Il; Jang, Su Jin; Park, Ju Hui; Lee, Yong Jin; Lee, Tae Sup; Woo, Kwang Sun; Park, Hyun; Choe, Jae Gol; An, Gwang Il; Kang, Joo Hyun

2014-10-01

Copper is an essential cofactor for a variety of biochemical processes including oxidative phosphorylation, cellular antioxidant activity, and elimination of free radicals. The copper transporter 1 is known to be involved in cellular uptake of copper ions. In this study, we evaluated the utility of human copper transporter 1 (hCTR1) gene as a new reporter gene for (64)Cu PET imaging. Human breast cancer cells (MDA-MB-231) were infected with a lentiviral vector constitutively expressing the hCTR1 gene under super cytomegalovirus promoter, and positive clones (MDA-MB-231-hCTR1) were selected. The expression of hCTR1 gene in MDA-MB-231-hCTR1 cells was measured by reverse transcription polymerase chain reaction, Western blot, and (64)Cu uptake assay. To evaluate the cytotoxic effects induced by hCTR1 expression, the dose-dependent cell survival rate after treatment with cisplatin (Cis-diaminedichloroplatinum (II) [CDDP]) was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and trypan blue dye exclusion. Small-animal PET images were acquired in tumor-bearing mice from 2 to 48 h after an intravenous injection of (64)Cu. The hCTR1 gene expression in MDA-MB-231-hCTR1 cells was confirmed at the RNA and protein expression and the cellular (64)Cu uptake level. MTT assay and trypan blue dye exclusion showed that the cell viability of MDA-MB-231-hCTR1 cells decreased more rapidly than that of MDA-MB-231 cells after treatment with CDDP for 96 or 72 h, respectively. Small-animal PET imaging revealed a higher accumulation of (64)Cu in MDA-MB-231-hCTR1 tumors than in MDA-MB-231 tumors. With respect to the biodistribution data, the percentage injected dose per gram of (64)Cu in the MDA-MB-231 tumors and MDA-MB-231-hCTR1 tumors at 48 h after (64)Cu injection was 2.581 ± 0.254 and 5.373 ± 1.098, respectively. An increase in (64)Cu uptake induced by the expression of hCTR1 gene was demonstrated in vivo and in vitro, suggesting the potential use

Copper aluminate spinel in the stabilization and detoxification of simulated copper-laden sludge.

PubMed

Tang, Yuanyuan; Shih, Kaimin; Chan, King

2010-06-01

This study aims to evaluate the feasibility of stabilizing copper-laden sludge by the application of alumina-based ceramic products. The processing temperature, material leaching behaviour, and the effect of detoxification were investigated in detail. CuO was used to simulate the copper-laden sludge and X-ray Diffraction was performed to monitor the incorporation of copper into the copper aluminate spinel (CuAl(2)O(4)) phase in ceramic products. It was found that the development of CuAl(2)O(4) increased with elevating temperatures up to and including 1000 degrees C in the 3h short-sintering scheme. When the sintering temperature went above 1000 degrees C, the CuAl(2)O(4) phase began to decompose due to the high temperature transformation to CuAlO(2). The leachability and leaching behaviour of CuO and CuAl(2)O(4) were compared by usage of a prolonged leaching test modified from US EPA's toxicity characteristic leaching procedure. The leaching results show that CuAl(2)O(4) is superior to CuO for the purpose of copper immobilization over longer leaching periods. Furthermore, the detoxification effect of CuAl(2)O(4) was tested through bacterial adhesion with Escherichia coli K12, and the comparison of bacterial adhesion on CuO and CuAl(2)O(4) surfaces shows the beneficial detoxification effect in connection with the formation of the CuAl(2)O(4) spinel. This study demonstrates the feasibility of transforming copper-laden sludge into the spinel phase by using readily available and inexpensive ceramic materials, and achieving a successful reduction of metal mobility and toxicity.

Biosorption of heavy metal copper (Cu2+) by Saccharomyces cerevisiae

NASA Astrophysics Data System (ADS)

Ririhena, S. A. J.; Astuti, A. D.; Fachrul, M. F.; Silalahi, M. D. S.; Hadisoebroto, R.; Rinanti, A.

2018-01-01

This research aims to study the optimum effect of contact time and pH adsorption of copper (Cu2+) from electroplating industry waste by dried beer waste S.cerevisiae. This research conducted using batch culture with pH variation 2,3,4,5, and 6, contact time variation 60, 90, 120, 150, 180 minutes, 150 rpm at room temperature (± 28°C), initial Cu2+ concentration 33,746 mg/l, and biosorbent mass 200 mg & 500 mg. The adsorption of heavy metal ions Cu2+ occurs in all variations of pH and contact time at optimum pH. The optimum adsorption occurs at pH 4 with contact time 120 minutes for both 200 mg (41.60%) and 500 mg (61.04%) beer waste biosorbent. Cell morphology seen with Scanning Electron Microscope (SEM) analysis shows the change of cell wall that gets damaged from Cu2+ adsorption. It also proved by the decreased concentration of initial high concentration carboxyl groups. The adsorption process of this research complies to Freundlich Isotherm with R2 value closest to 1 and followed first order kinetic.

Origin of native copper in the Paraná volcanic province, Brazil, integrating Cu stable isotopes in a multi-analytical approach

NASA Astrophysics Data System (ADS)

Baggio, Sérgio Benjamin; Hartmann, Léo Afraneo; Lazarov, Marina; Massonne, Hans-Joachim; Opitz, Joachim; Theye, Thomas; Viefhaus, Tillmann

2018-03-01

Different hypotheses exist on the origin of native copper mineralization in the Paraná volcanic province that invoke magmatic, late magmatic, or hydrothermal events. The average copper content in the host basalts is 200 ppm. Native copper occurs as dendrites in cooling joints, fractures, and cavities within amygdaloidal crusts. Cuprite, tenorite, chrysocolla, malachite, and azurite occur in breccias at the top of the lava flows. Chemical analyses, X-ray diffraction, Raman spectrometry, electron microprobe analyses, LA-ICP-MS, and Cu isotope analyses were used to evaluate the origin of native copper in the volcanic province. Copper contents in magnetite of the host basalt are close to 1 wt.%, whereas clinopyroxene contains up to 0.04 wt.% Cu. Cretaceous hydrothermal alteration of magnetite and clinopyroxene released copper to generate hydrothermal copper mineralization. The isotopic composition of the native copper in the Paraná volcanic province varies from -0.9‰ in the southeastern portion (Rio Grande do Sul state) to 1.9‰ in the central portion (Paraná state) of the province. This study supports a hydrothermal origin followed by supergene enrichment for native copper in the Paraná volcanic province.

Enriching and Separating Primary Copper Impurity from Pb-3 Mass Pct Cu Melt by Super-Gravity Technology

NASA Astrophysics Data System (ADS)

Yang, Yuhou; Song, Bo; Song, Gaoyang; Yang, Zhanbing; Xin, Wenbin

2016-10-01

In this study, super-gravity technology was introduced in the lead bullion-refining process to investigate the enriching and separating laws of copper impurity from Pb-3 mass pct Cu melt. With the gravity coefficient G = 700 at the cooling rate of ν = 5 K min-1, the entire copper phase gathers at the upper area of the sample, and it is hard to find any copper particles at the bottom area of the sample. The floatation movement of copper phase was greatly intensified by super gravity and the mass pct of copper in tailing lead is up to 8.631 pct, while that in the refined lead is only 0.113 pct. The refining rate of lead bullion reached up to 94.27 pct. Copper-phase impurity can be separated effectively from Pb-3 mass pct Cu melt by filtration method in super-gravity field, and the separation efficiency increased with the increasing gravity coefficient in the range of G ≥ 10. After filtration at 613 K (340 °C) with gravity coefficient G = 100 for 10 minutes, the refined lead, with just 0.157 mass pct copper impurity, was separated to the bottom of the crucible, and the copper dross containing only 23.56 mass pct residual lead was intercepted by the carbon fiber felt, leading to the separation efficiency up to 96.18 pct (meaning a great reduction in metal loss).

Iron Sulfide Attenuates the Methanogenic Toxicity of Elemental Copper and Zinc Oxide Nanoparticles and their Soluble Metal Ion Analogs

PubMed Central

Gonzalez-Estrella, Jorge; Gallagher, Sara; Sierra-Alvarez, Reyes; Field, Jim A.

2016-01-01

Elemental copper (Cu0) and zinc oxide (ZnO) nanoparticle (NP) toxicity to methanogens has been attributed to the release of soluble metal ions. Iron sulfide (FeS) partially controls the soluble concentration of heavy metals and their toxicity in aquatic environments. Heavy metals displace the Fe from FeS forming poorly soluble metal sulfides in the FeS matrix. Therefore, FeS may be expected to attenuate the NP toxicity. This work assessed FeS as an attenuator of the methanogenic toxicity of Cu0 and ZnO NPs and their soluble salt analogs. The toxicity attenuation capacity of fine (25–75 µm) and coarse (500 to 1200 µm) preparations of FeS (FeS-f and FeS-c respectively) was tested in the presence of highly inhibitory concentrations of CuCl2, ZnCl2 Cu0 and ZnO NPs. FeS-f attenuated methanogenic toxicity better than FeS-c. The results revealed that 2.5× less FeS-f than FeS-c was required to recover the methanogenic activity to 50% (activity normalized to uninhibited controls). The results also indicated that a molar FeS-f/Cu0 NP, FeS-f/ZnO NP, FeS-f/ZnCl2, and FeS-f/CuCl2 ratio of 2.14, 2.14, 4.28, and 8.56 respectively, was necessary to recover the methanogenic activity to >75%. Displacement experiments demonstrated that CuCl2 and ZnCl2 partially displaced Fe from FeS. As a whole, the results indicate that not all the sulfide in FeS was readily available to react with the soluble Cu and Zn ions which may explain the need for a large stoichiometric excesses of FeS to highly attenuate Cu and Zn toxicity. Overall, this study provides evidence that FeS attenuates the toxicity caused by Cu0 and ZnO NPs and their soluble ion analogs to methanogens. PMID:26803736

Friction and transfer of copper, silver, and gold to iron in the presence of various adsorbed surface films

NASA Technical Reports Server (NTRS)

Buckley, D. H.

1979-01-01

Sliding friction experiments were conducted with the noble metals copper, silver, and gold and two binary alloys of these metals contacting iron in the presence of various adsorbates including, oxygen, methyl mercaptan, and methyl chloride. A pin on disk specimen configuration was used with a load of 100 grams, sliding velocity of 60 mm/min; at 25 C with the surfaces saturated with the adsorbates. Auger emission spectroscopy was used to monitor surface films. Results of the experiments indicate that friction and transfer characteristics are highly specific with respect to both the noble metal and surface film present. With all three metals and films transfer of the noble metal to iron occurred very rapidly. With all metals and films transfer of the noble metal to iron continuously increased with repeated passes except for silver and copper sliding on iron sulfide.

Zebrafish in the sea of mineral (iron, zinc, and copper) metabolism

PubMed Central

Zhao, Lu; Xia, Zhidan; Wang, Fudi

2014-01-01

Iron, copper, zinc, and eight other minerals are classified as essential trace elements because they present in minute in vivo quantities and are essential for life. Because either excess or insufficient levels of trace elements can be detrimental to life (causing human diseases such as iron-deficiency anemia, hemochromatosis, Menkes syndrome and Wilson's disease), the endogenous levels of trace minerals must be tightly regulated. Many studies have demonstrated the existence of systems that maintain trace element homeostasis, and these systems are highly conserved in multiple species ranging from yeast to mice. As a model for studying trace mineral metabolism, the zebrafish is indispensable to researchers. Several large-scale mutagenesis screens have been performed in zebrafish, and these screens led to the identification of a series of metal transporters and the generation of several mutagenesis lines, providing an in-depth functional analysis at the system level. Moreover, because of their developmental advantages, zebrafish have also been used in mineral metabolism-related chemical screens and toxicology studies. Here, we systematically review the major findings of trace element homeostasis studies using the zebrafish model, with a focus on iron, zinc, copper, selenium, manganese, and iodine. We also provide a homology analysis of trace mineral transporters in fish, mice and humans. Finally, we discuss the evidence that zebrafish is an ideal experimental tool for uncovering novel mechanisms of trace mineral metabolism and for improving approaches to treat mineral imbalance-related diseases. PMID:24639652

Copper diffusion and mechanical toughness at Cu-silica interfaces glued with polyelectrolyte nanolayers

NASA Astrophysics Data System (ADS)

Gandhi, D. D.; Singh, A. P.; Lane, M.; Eizenberg, M.; Ramanath, G.

2007-04-01

We demonstrate the use of polyallylamine hydrochloride (PAH)-polystyrene sulfonate (PSS) nanolayers to block Cu transport into silica. Cu/PSS-PAH/SiO2 structures show fourfold enhancement in device failure times during bias thermal annealing at 200 °C at an applied electric field of 2 MV/cm, when compared with structures with pristine Cu-SiO2 interfaces. Although the bonding at both Cu-PSS and PAH-SiO2 interfaces are strong, the interfacial toughness measured by the four-point bend tests is ˜2 Jm-2. Spectroscopic analysis of fracture surfaces reveals that weak electrostatic bonding at the PSS-PAH interface is responsible for the low toughness. Similar behavior is observed for Cu-SiO2 interfaces modified with other polyelectrolyte bilayers that inhibit Cu diffusion. Thus, while strong bonding at Cu-barrier and barrier-dielectric interfaces may be sufficient for blocking copper transport across polyelectrolyte bilayers, strong interlayer molecular bonding is a necessary condition for interface toughening. These findings are of importance for harnessing MNLs for use in future device wiring applications.

Giant Paramagnetism of Copper Nanoparticles in Nanocomposites Cu@C

NASA Astrophysics Data System (ADS)

Sharoyan, Eduard; Mirzakhanyan, Armen; Gyulasaryan, Harutyun; Manukyan, Aram; Estiphanos, Medhanie; Goff, Michael; Bernal, Oscar; Kocharian, Armen

The copper nanoparticles in nanocomposites Cu@C, encapsulated in graphitized carbon shell was obtained by the solid-phase pyrolysis method of polycrystalline phthalocyanine (CuPc, Pc =C32N8H16) . The average sizes of the nanoparticles are in the range of 2-6 nm. Magnetic measurements were carried out by vibrational magnetometer in the temperature range 10-300 K. At low temperatures (<70K) we observed a giant paramagnetism, apparently due to the (ballistic) conduction electron (large orbital magnetism). The values of the specific susceptibility at T = 10K with magnetic specific susceptibility of 510-5 emu/gOe order. This work was supported by the RA MES State Committee of Science, in the frames of the research project SCS-13-1C090. The work at California State University was supported by the National Science Foundation-Partnerships for Research and Education in Materials under Grant DMR-1523588.

Copper-containing zeolite catalysts

DOEpatents

Price, G.L.; Kanazirev, V.

1996-12-10

A catalyst useful in the conversion of nitrogen oxides or in the synthesis of nitriles or imines from amines, is formed by preparing an intimate mechanical mixture of a copper (II)-containing species, such as CuO or CuCl{sub 2}, or elemental copper, with a zeolite having a pore mouth comprising 10 oxygen atoms, such as ZSM-5, converting the elemental copper or copper (II) to copper (I), and driving the copper (I) into the zeolite.

Copper-containing zeolite catalysts

DOEpatents

Price, Geoffrey L.; Kanazirev, Vladislav

1996-01-01

A catalyst useful in the conversion of nitrogen oxides or in the synthesis of nitriles or imines from amines, formed by preparing an intimate mechanical mixture of a copper (II)-containing species, such as CuO or CuCl.sub.2, or elemental copper, with a zeolite having a pore mouth comprising 10 oxygen atoms, such as ZSM-5, converting the elemental copper or copper (II) to copper (I), and driving the copper (I) into the zeolite.

Co-reduction of Copper Smelting Slag and Nickel Laterite to Prepare Fe-Ni-Cu Alloy for Weathering Steel

NASA Astrophysics Data System (ADS)

Guo, Zhengqi; Pan, Jian; Zhu, Deqing; Zhang, Feng

2018-02-01

In this study, a new technique was proposed for the economical and environmentally friendly recovery of valuable metals from copper smelting slag while simultaneously upgrading nickel laterite through a co-reduction followed by wet magnetic separation process. Copper slag with a high FeO content can decrease the liquidus temperature of the SiO2-Al2O3-CaO-MgO system and facilitate formation of liquid phase in a co-reduction process with nickel laterite, which is beneficial for metallic particle growth. As a result, the recovery of Ni, Cu, and Fe was notably increased. A crude Fe-Ni-Cu alloy with 2.5% Ni, 1.1% Cu, and 87.9% Fe was produced, which can replace part of scrap steel, electrolytic copper, and nickel as the burden in the production of weathering steel by an electric arc furnace. The study further found that an appropriate proportion of copper slag and nickel laterite in the mixture is essential to enhance the reduction, acquire appropriate amounts of the liquid phase, and improve the growth of the metallic alloy grains. As a result, the liberation of alloy particles in the grinding process was effectively promoted and the metal recovery was increased significantly in the subsequent magnetic separation process.

Widespread Distribution and Functional Specificity of the Copper Importer CcoA: Distinct Cu Uptake Routes for Bacterial Cytochrome c Oxidases

DOE PAGES

Khalfaoui-Hassani, Bahia; Wu, Hongjiang; Blaby-Haas, Crysten E.; ...

2018-02-27

ABSTRACT Cytochromecoxidases are members of the heme-copper oxidase superfamily. These enzymes have different subunits, cofactors, and primary electron acceptors, yet they all contain identical heme-copper (Cu B) binuclear centers within their catalytic subunits. The uptake and delivery pathways of the Cu Batom incorporated into this active site, where oxygen is reduced to water, are not well understood. Our previous work with the facultative phototrophic bacteriumRhodobacter capsulatusindicated that the copper atom needed for the Cu Bsite ofcbb 3-type cytochromecoxidase (cbb 3-Cox) is imported to the cytoplasm by a major facilitator superfamily-type transporter, CcoA. In this study, a comparative genomic analysis ofmore » CcoA orthologs in alphaproteobacterial genomes showed that CcoA is widespread among organisms and frequently co-occurs with cytochromecoxidases. To define the specificity of CcoA activity, we investigated its function inRhodobacter sphaeroides, a close relative ofR. capsulatusthat contains bothcbb 3- andaa 3-Cox. Phenotypic, genetic, and biochemical characterization of mutants lacking CcoA showed that in its absence, or even in the presence of its bypass suppressors, only the production ofcbb 3-Cox and not that ofaa 3-Cox was affected. We therefore concluded that CcoA is dedicated solely tocbb 3-Cox biogenesis, establishing that distinct copper uptake systems provide the Cu Batoms to the catalytic sites of these two similar cytochromecoxidases. These findings illustrate the large variety of strategies that organisms employ to ensure homeostasis and fine control of copper trafficking and delivery to the target cuproproteins under different physiological conditions. IMPORTANCEThecbb 3- andaa 3-type cytochromecoxidases belong to the widespread heme-copper oxidase superfamily. They are membrane-integral cuproproteins that catalyze oxygen reduction to water under hypoxic and normoxic growth conditions. These enzymes diverge in terms of subunit and

Widespread Distribution and Functional Specificity of the Copper Importer CcoA: Distinct Cu Uptake Routes for Bacterial Cytochrome c Oxidases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khalfaoui-Hassani, Bahia; Wu, Hongjiang; Blaby-Haas, Crysten E.

ABSTRACT Cytochromecoxidases are members of the heme-copper oxidase superfamily. These enzymes have different subunits, cofactors, and primary electron acceptors, yet they all contain identical heme-copper (Cu B) binuclear centers within their catalytic subunits. The uptake and delivery pathways of the Cu Batom incorporated into this active site, where oxygen is reduced to water, are not well understood. Our previous work with the facultative phototrophic bacteriumRhodobacter capsulatusindicated that the copper atom needed for the Cu Bsite ofcbb 3-type cytochromecoxidase (cbb 3-Cox) is imported to the cytoplasm by a major facilitator superfamily-type transporter, CcoA. In this study, a comparative genomic analysis ofmore » CcoA orthologs in alphaproteobacterial genomes showed that CcoA is widespread among organisms and frequently co-occurs with cytochromecoxidases. To define the specificity of CcoA activity, we investigated its function inRhodobacter sphaeroides, a close relative ofR. capsulatusthat contains bothcbb 3- andaa 3-Cox. Phenotypic, genetic, and biochemical characterization of mutants lacking CcoA showed that in its absence, or even in the presence of its bypass suppressors, only the production ofcbb 3-Cox and not that ofaa 3-Cox was affected. We therefore concluded that CcoA is dedicated solely tocbb 3-Cox biogenesis, establishing that distinct copper uptake systems provide the Cu Batoms to the catalytic sites of these two similar cytochromecoxidases. These findings illustrate the large variety of strategies that organisms employ to ensure homeostasis and fine control of copper trafficking and delivery to the target cuproproteins under different physiological conditions. IMPORTANCEThecbb 3- andaa 3-type cytochromecoxidases belong to the widespread heme-copper oxidase superfamily. They are membrane-integral cuproproteins that catalyze oxygen reduction to water under hypoxic and normoxic growth conditions. These enzymes diverge in terms of subunit and

Efficient organic solar cells using copper(I) iodide (CuI) hole transport layers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peng, Ying; Department of Physics and Centre for Plastic Electronics, Blackett Laboratory, Imperial College London, London SW7 2AZ; Yaacobi-Gross, Nir

We report the fabrication of high power conversion efficiency (PCE) polymer/fullerene bulk heterojunction (BHJ) photovoltaic cells using solution-processed Copper (I) Iodide (CuI) as hole transport layer (HTL). Our devices exhibit a PCE value of ∼5.5% which is equivalent to that obtained for control devices based on the commonly used conductive polymer poly(3,4-ethylenedioxythiophene): polystyrenesulfonate as HTL. Inverted cells with PCE >3% were also demonstrated using solution-processed metal oxide electron transport layers, with a CuI HTL evaporated on top of the BHJ. The high optical transparency and suitable energetics of CuI make it attractive for application in a range of inexpensive large-area optoelectronicmore » devices.« less

Characterization and mechanism of copper biosorption by a highly copper-resistant fungal strain isolated from copper-polluted acidic orchard soil.

PubMed

Tu, Chen; Liu, Ying; Wei, Jing; Li, Lianzhen; Scheckel, Kirk G; Luo, Yongming

2018-06-22

In this paper, a highly copper-resistant fungal strain NT-1 was characterized by morphological, physiological, biochemical, and molecular biological techniques. Physiological response to Cu(II) stress, effects of environmental factors on Cu(II) biosorption, as well as mechanisms of Cu(II) biosorption by strain NT-1 were also investigated in this study. The results showed that NT-1 belonged to the genus Gibberella, which exhibited high tolerance to both acidic conditions and Cu(II) contamination in the environment. High concentrations of copper stress inhibited the growth of NT-1 to various degrees, leading to the decreases in mycelial biomass and colony diameter, as well as changes in morphology. Under optimal conditions (initial copper concentration: 200 mg L -1 , temperature 28 °C, pH 5.0, and inoculum dose 10%), the maximum copper removal percentage from solution through culture of strain NT-1 within 5 days reached up to 45.5%. The biosorption of Cu(II) by NT-1 conformed to quasi-second-order kinetics and Langmuir isothermal adsorption model and was confirmed to be a monolayer adsorption process dominated by surface adsorption. The binding of NT-1 to Cu(II) was mainly achieved by forming polydentate complexes with carboxylate and amide group through covalent interactions and forming Cu-nitrogen-containing heterocyclic complexes via Cu(II)-π interaction. The results of this study provide a new fungal resource and key parameters influencing growth and copper removal capacity of the strain for developing an effective bioremediation strategy for copper-contaminated acidic orchard soils.

The metal-insulator transition in Fe(1.01-x)Cu(x)Se.

PubMed

Williams, A J; McQueen, T M; Ksenofontov, V; Felser, C; Cava, R J

2009-07-29

Iron selenide, Fe(1.01)Se, the layered parent compound of the recently discovered superconducting arsenide family, has previously been shown to be non-magnetic and superconducting with a critical temperature of 8 K. Here we show that copper can be substituted at the iron site in Fe(1.01)Se up to a solubility limit of 20-30%, after which a first-order transition to the three-dimensional CuFeSe(2) structure type is observed. As little as 1.5% copper is sufficient to suppress the superconductivity, and 4% drives the system through a metal-insulator transition. A local magnetic moment is introduced, which maximizes near 12% doping, where a spin-glass transition near 15 K is observed.

CeO2-CuO/Cu2O/Cu monolithic catalysts with three-kind morphologies Cu2O layers for preferential CO oxidation

NASA Astrophysics Data System (ADS)

Jing, Guojuan; Zhang, Xuejiao; Zhang, Aiai; Li, Meng; Zeng, Shanghong; Xu, Changjin; Su, Haiquan

2018-03-01

The supports of copper slices with three-kind morphologies Cu2O layers were prepared by the hydrothermal method. The Cu2O layers are rod-like structure, three-dimensional reticular and porous morphology as well as flower-like morphology, respectively. The CeO2-CuO/Cu2O/Cu monolithic catalysts present porous and network structure or foam morphology after loading CeO2 and CuO. Cu and Ce elements are uniformly dispersed onto the support surface. It is found that the monolithic catalyst with flower-like Cu2O layer displays better low-temperature activity because of highly-dispersed CuO and high Olatt concentration. The monolithic catalysts with rod-like or reticular-morphology Cu2O layers present high-temperature activity due to larger CuO crystallite sizes and good synergistic effect at copper-ceria interfacial sites. The as-prepared CeO2-CuO/Cu2O/Cu monolithic catalysts show good performance in the CO-PROX reaction. The generation of Cu2O layers with three-kind morphologies is beneficial to the loading and dispersion of copper oxides and ceria.

Stage specific effects of soluble copper and copper oxide nanoparticles during sea urchin embryo development and their relation to intracellular copper uptake.

PubMed

Torres-Duarte, Cristina; Ramos-Torres, Karla M; Rahimoff, René; Cherr, Gary N

2017-08-01

The effects of exposure to either soluble copper (copper sulfate) or copper oxide nanoparticles (nano-CuO) during specific early developmental stages of sea urchin embryos were analyzed. Soluble copper caused significant malformations in embryos (skeletal malformations, delayed development or gut malformations) when present at any given stage, while cleavage stage was the most sensitive to nano-CuO exposure causing skeletal malformations and decreased total antioxidant capacity. The stage specificity was linked to higher endocytic activity during the first hours of development that leads to higher accumulation of copper in specific cells critical for development. Results indicate that nano-CuO results in higher accumulation of copper inside of embryos and this intracellular copper is more persistent as compared to soluble copper. The possible implications later in development are discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Copper Salts Mediated Morphological Transformation of Cu2O from Cubes to Hierarchical Flower-like or Microspheres and Their Supercapacitors Performances

PubMed Central

Chen, Liang; Zhang, Yu; Zhu, Pengli; Zhou, Fengrui; Zeng, Wenjin; Lu, Daoqiang Daniel; Sun, Rong; Wong, Chingping

2015-01-01

Monodisperse Cu2O of different microstructures, such as cubes, flower-like, and microspheres, have been extensively synthesized by a simple polyol reduction method using different copper salts, i.e. (Cu(acac)2, Cu(OH)2, and Cu(Ac)2·H2O). The effects of copper salts on the morphology of Cu2O were investigated in details through various characterization methods, including X-ray diffraction, transmission electron microscopy, scanning electron microscopy and UV-Vis absorption spectra. The effects of morphology on the electrochemical properties were further studied. Among the different structures, Cu2O with the microspheric morphology shows the highest specific capacitance and the best cycling stability compared with those of the other two structures, thus bear larger volume charge during the electrochemical reaction due to the microspheres of small nanoparticles. PMID:25857362

Copper doping of ZnO crystals by transmutation of 64Zn to 65Cu: An electron paramagnetic resonance and gamma spectroscopy study

NASA Astrophysics Data System (ADS)

Recker, M. C.; McClory, J. W.; Holston, M. S.; Golden, E. M.; Giles, N. C.; Halliburton, L. E.

2014-06-01

Transmutation of 64Zn to 65Cu has been observed in a ZnO crystal irradiated with neutrons. The crystal was characterized with electron paramagnetic resonance (EPR) before and after the irradiation and with gamma spectroscopy after the irradiation. Major features in the gamma spectrum of the neutron-irradiated crystal included the primary 1115.5 keV gamma ray from the 65Zn decay and the positron annihilation peak at 511 keV. Their presence confirmed the successful transmutation of 64Zn nuclei to 65Cu. Additional direct evidence for transmutation was obtained from the EPR of Cu2+ ions (where 63Cu and 65Cu hyperfine lines are easily resolved). A spectrum from isolated Cu2+ (3d9) ions acquired after the neutron irradiation showed only hyperfine lines from 65Cu nuclei. The absence of 63Cu lines in this Cu2+ spectrum left no doubt that the observed 65Cu signals were due to transmuted 65Cu nuclei created as a result of the neutron irradiation. Small concentrations of copper, in the form of Cu+-H complexes, were inadvertently present in our as-grown ZnO crystal. These Cu+-H complexes are not affected by the neutron irradiation, but they dissociate when a crystal is heated to 900 °C. This behavior allowed EPR to distinguish between the copper initially in the crystal and the copper subsequently produced by the neutron irradiation. In addition to transmutation, a second major effect of the neutron irradiation was the formation of zinc and oxygen vacancies by displacement. These vacancies were observed with EPR.

Determining Prehistoric Mining Practices in Southeastern Europe Using Copper Isotopes

NASA Astrophysics Data System (ADS)

Powell, Wayne; Mathur, Ryan; Bankoff, H. Arthur; Bulatović, Aleksandar; Filipović, Vojislav

2017-04-01

from an average of 164 published measurements from chalcopyrite and bornite from 8 epithermal and massive sulfide deposits. Twenty-two (88%) of Eneolithic artifacts (n=25) have values greater than this, whereas eight (73%) of the Early Bronze age artifacts (n=11) yield compositions less than -0.2‰. The mean of Middle Bronze Age, Late Bronze Age and Early Iron Age (n=86) cluster near -0.2‰. This pattern is consistent with a progression to the mining of ore assemblages from increasing depths through prehistory. The shift from 65Cu-enriched to 65Cu-depleted copper in artifacts across the Eneolithic-Bronze Age boundary at 2500 BCE indicates that accessible near-surface oxide ore reserves were depleted after approximately two millennia of mining, and that the beginning of the Bronze Age in the Balkans corresponded to the acquisition of pyrotechnology which allowed for the extraction of metals from sulfide minerals and the resumption of copper mining activity in the region.

Methanobactin and the Link between Copper and Bacterial Methane Oxidation

PubMed Central

Semrau, Jeremy D.; Murrell, J. Colin; Gallagher, Warren H.; Dennison, Christopher; Vuilleumier, Stéphane

2016-01-01

SUMMARY Methanobactins (mbs) are low-molecular-mass (<1,200 Da) copper-binding peptides, or chalkophores, produced by many methane-oxidizing bacteria (methanotrophs). These molecules exhibit similarities to certain iron-binding siderophores but are expressed and secreted in response to copper limitation. Structurally, mbs are characterized by a pair of heterocyclic rings with associated thioamide groups that form the copper coordination site. One of the rings is always an oxazolone and the second ring an oxazolone, an imidazolone, or a pyrazinedione moiety. The mb molecule originates from a peptide precursor that undergoes a series of posttranslational modifications, including (i) ring formation, (ii) cleavage of a leader peptide sequence, and (iii) in some cases, addition of a sulfate group. Functionally, mbs represent the extracellular component of a copper acquisition system. Consistent with this role in copper acquisition, mbs have a high affinity for copper ions. Following binding, mbs rapidly reduce Cu2+ to Cu1+. In addition to binding copper, mbs will bind most transition metals and near-transition metals and protect the host methanotroph as well as other bacteria from toxic metals. Several other physiological functions have been assigned to mbs, based primarily on their redox and metal-binding properties. In this review, we examine the current state of knowledge of this novel type of metal-binding peptide. We also explore its potential applications, how mbs may alter the bioavailability of multiple metals, and the many roles mbs may play in the physiology of methanotrophs. PMID:26984926

Relative contributions of copper oxide nanoparticles and dissolved copper to Cu uptake kinetics of Gulf killifish (Fundulus grandis) embryos

USGS Publications Warehouse

Jiang, Chuanjia; Castellon, Benjamin T.; Matson, Cole W.; Aiken, George R.; Hsu-Kim, Heileen

2017-01-01

The toxicity of soluble metal-based nanomaterials may be due to the uptake of metals in both dissolved and nanoparticulate forms, but the relative contributions of these different forms to overall metal uptake rates under environmental conditions are not quantitatively defined. Here, we investigated the linkage between the dissolution rates of copper(II) oxide (CuO) nanoparticles (NPs) and their bioavailability to Gulf killifish (Fundulus grandis) embryos, with the aim of quantitatively delineating the relative contributions of nanoparticulate and dissolved species for Cu uptake. Gulf killifish embryos were exposed to dissolved Cu and CuO NP mixtures comprising a range of pH values (6.3–7.5) and three types of natural organic matter (NOM) isolates at various concentrations (0.1–10 mg-C L–1), resulting in a wide range of CuO NP dissolution rates that subsequently influenced Cu uptake. First-order dissolution rate constants of CuO NPs increased with increasing NOM concentration and for NOM isolates with higher aromaticity, as indicated by specific ultraviolet absorbance (SUVA), while Cu uptake rate constants of both dissolved Cu and CuO NP decreased with NOM concentration and aromaticity. As a result, the relative contribution of dissolved Cu and nanoparticulate CuO species for the overall Cu uptake rate was insensitive to NOM type or concentration but largely determined by the percentage of CuO that dissolved. These findings highlight SUVA and aromaticity as key NOM properties affecting the dissolution kinetics and bioavailability of soluble metal-based nanomaterials in organic-rich waters. These properties could be used in the incorporation of dissolution kinetics into predictive models for environmental risks of nanomaterials.

Formation of copper aluminate spinel and cuprous aluminate delafossite to thermally stabilize simulated copper-laden sludge.

PubMed

Hu, Ching-Yao; Shih, Kaimin; Leckie, James O

2010-09-15

The study reported herein indicated the stabilization mechanisms at work when copper-laden sludge is thermally treated with gamma-alumina and kaolinite precursors, and evaluated the prolonged leachability of their product phases. Four copper-containing phases - copper oxide (CuO), cuprous oxide (Cu(2)O), copper aluminate spinel (CuAl(2)O(4)), and cuprous aluminate delafossite (CuAlO(2)) - were found in the thermal reactions of the investigated systems. These phases were independently synthesized for leaching by 0.1M HCl aqueous solution, and the relative leachabilities were found to be CuAl(2)O(4)<CuAlO(2)<Cu(2)O<CuO. The sintering condition and formation mechanism employed to stabilize copper into CuAl(2)O(4) and CuAlO(2) are extensively discussed here. With a 3h of short sintering, it was found that CuAl(2)O(4) could be effectively formed between 850 and 950 degrees C by the gamma-alumina precursor. Although kaolinite had a lower incorporation capability than gamma-alumina, it was found to transform a considerable amount of copper into CuAl(2)O(4) between 950 and 1000 degrees C. At higher temperatures, CuAlO(2) was produced only in the gamma-alumina system as the occurrence of Cu(2)O-cristobalite solution in the kaolinite system precluded the production of CuAlO(2). The hypothesis that the spinel formation mechanism has two stages was supported by the results of the changing Cu/Al mole ratio in the system, and the rate-limiting step was identified as the diffusion process in the second stage. Copyright 2010 Elsevier B.V. All rights reserved.

Copper stabilization in beneficial use of waterworks sludge and copper-laden electroplating sludge for ceramic materials.

PubMed

Tang, Yuanyuan; Chan, Siu-Wai; Shih, Kaimin

2014-06-01

A promising strategy for effectively incorporating metal-containing waste materials into a variety of ceramic products was devised in this study. Elemental analysis confirmed that copper was the predominant metal component in the collected electroplating sludge, and aluminum was the predominant constituent of waterworks sludge collected in Hong Kong. The use of waterworks sludge as an aluminum-rich precursor material to facilitate copper stabilization under thermal conditions provides a promising waste-to-resource strategy. When sintering the mixture of copper sludge and the 900 °C calcined waterworks sludge, the CuAl2O4 spinel phase was first detected at 650 °C and became the predominant product phase at temperatures higher than 850 °C. Quantification of the XRD pattern using the Rietveld refinement method revealed that the weight of the CuAl2O4 spinel phase reached over 50% at 850 °C. The strong signals of the CuAl2O4 phase continued until the temperature reached 1150 °C, and further sintering initiated the generation of the other copper-hosting phases (CuAlO2, Cu2O, and CuO). The copper stabilization effect was evaluated by the copper leachability of the CuAl2O4 and CuO via the prolonged leaching experiments at a pH value of 4.9. The leaching results showed that the CuAl2O4 phase was superior to the CuAlO2 and CuO phases for immobilizing hazardous copper over longer leaching periods. The findings clearly indicate that spinel formation is the most crucial metal stabilization mechanism when sintering multiphase copper sludge with aluminum-rich waterworks sludge, and suggest a promising and reliable technique for reusing both types of sludge waste for ceramic materials. Copyright © 2013 Elsevier Ltd. All rights reserved.

Influence of Oxygen on Cu Distribution Behavior Between Molten Iron and FeS-Based Flux

NASA Astrophysics Data System (ADS)

Kang, Youngjo; Shin, Kil-Sun; Morita, Kazuki

2018-06-01

Cu distribution behavior between molten iron and a sulfide flux was investigated under different oxygen contents in the sulfide flux to clarify the effect of oxygen content in FeS-based flux on Cu removal. The activity coefficient of CuS0.5 could be experimentally estimated according to the oxygen content. Based on the present result, the possibility of Cu removal by sulfide flux containing a certain amount of oxide was discussed.

Forming YBa2Cu3O7-x Superconductors On Copper Substrates

NASA Technical Reports Server (NTRS)

Mackenzie, J. Devin; Young, Stanley G.

1991-01-01

Experimental process forms layer of high-critical-temperature ceramic superconductor YBa2Cu3O7-x on surface of copper substrate. Offers possible solution to problem of finishing ceramic superconductors to required final sizes and shapes (difficult problem because these materials brittle and cannot be machined or bent). Further research necessary to evaluate superconducting qualities of surface layers and optimize process.

The Effect of Copper Addition on the Properties of Sn-0.7Cu Solder Paste

NASA Astrophysics Data System (ADS)

Said, R. M.; Mohamad Johari, F. H.; Salleh, M. A. A. Mohd; Sandu, A. V.

2018-03-01

The effect of copper addition on the properties of Sn-Cu based solder paste were investigate through this study. The Sn-0.7Cu solder paste doped with different concentration of Cu were prepared using solder paste mixture. The bulk solder microstructure of assolidified solder paste was studied. Besides that, intermetallic compound (IMC) formation on Cu substrate and hardness of all solder paste also being investigated. Results shows that increasing Cu concentration cause formation of large Cu6Sn5 IMC at bulk solder and the size of the IMC grew larger at high temperature. In addition, β-Sn area reduce when Cu concentration was high. The IMC morphology for all solder paste almost remain unchanged. However, there are large Cu6Sn5 IMC form near the interfacial IMC in Sn-Cu solder paste with high amount of Cu (Sn-10Cu). The hardness value was decrease when processing temperature at 250 °C due to present of small void in the microstructure while hardness of solder material increased at high temperature.

A new technique for online measurement of total and water-soluble copper (Cu) in coarse particulate matter (PM).

PubMed

Wang, Dongbin; Shafer, Martin M; Schauer, James J; Sioutas, Constantinos

2015-04-01

This study presents a novel system for online, field measurement of copper (Cu) in ambient coarse (2.5-10 μm) particulate matter (PM). This new system utilizes two virtual impactors combined with a modified liquid impinger (BioSampler) to collect coarse PM directly as concentrated slurry samples. The total and water-soluble Cu concentrations are subsequently measured by a copper Ion Selective Electrode (ISE). Laboratory evaluation results indicated excellent collection efficiency (over 85%) for particles in the coarse PM size ranges. In the field evaluations, very good agreements for both total and water-soluble Cu concentrations were obtained between online ISE-based monitor measurements and those analyzed by means of inductively coupled plasma mass spectrometry (ICP-MS). Moreover, the field tests indicated that the Cu monitor could achieve near-continuous operation for at least 6 consecutive days (a time resolution of 2-4 h) without obvious shortcomings. Copyright © 2015 Elsevier Ltd. All rights reserved.

Towards understanding the kinetic behaviour and limitations in photo-induced copper(i) catalyzed azide-alkyne cycloaddition (CuAAC) reactions.

PubMed

El-Zaatari, Bassil M; Shete, Abhishek U; Adzima, Brian J; Kloxin, Christopher J

2016-09-14

The kinetic behaviour of the photo-induced copper(i) catalyzed azide-alkyne cycloaddition (CuAAC) reaction was studied in detail using real-time Fourier transform infrared (FTIR) spectroscopy on both a solvent-based monofunctional and a neat polymer network forming system. The results in the solvent-based system showed near first-order kinetics on copper and photoinitiator concentrations up to a threshold value in which the kinetics switch to zeroth-order. This kinetic shift shows that the photo-CuAAC reaction is not susceptible from side reactions such as copper disproportionation, copper(i) reduction, and radical termination at the early stages of the reaction. The overall reaction rate and conversion is highly dependent on the initial concentrations of photoinitiator and copper(ii) as well as their relative ratios. The conversion was decreased when an excess of photoinitiator was utilized compared to its threshold value. Interestingly, the reaction showed an induction period at relatively low intensities. The induction period is decreased by increasing light intensity and photoinitiator concentration. The reaction trends and limitations were further observed in a solventless polymer network forming system, exhibiting a similar copper and photoinitiator threshold behaviour.

Towards understanding the kinetic behaviour and limitations in photo-induced copper(I) catalyzed azide-alkyne cycloaddition (CuAAC) reactions

PubMed Central

El-Zaatari, Bassil M.; Shete, Abhishek U.; Adzima, Brian J.; Kloxin, Christopher J.

2016-01-01

The kinetic behaviour of the photo-induced copper(I) catalyzed azide—alkyne cycloaddition (CuAAC) reaction was studied in detail using real-time Fourier Transform Infrared Spectroscopy (FTIR) on both a solvent-based monofunctional and a neat polymer network forming system. The results in the solvent-based system showed near first-order kinetics on copper and photoinitiator concentrations up to a threshold value in which the kinetics switch to zeroth-order. This kinetic shift shows that the photo-CuAAC reaction is not suseptible from side reactions such as copper disproportionation, copper(I) reduction, and radical termination at the early stages of the reaction. The overall reaction rate and conversion is highly dependent on the initial concentrations of photoinitiator and copper(II), as well as their relative ratios. The conversion was decreased when an excess of photoinitiator was utilized compared to its threshold value. Interestingly, the reaction showed an induction period at relatively low intensities. The induction period is decreased by increasing light intensity, and photoinitiator concentration. The reaction trends and limitations were further observed in a solventless polymer network forming system, exhibiting a similar copper and photoinitiator threshold behaviour. PMID:27711587

Alteration of the Copper-Binding Capacity of Iron-Rich Humic Colloids during Transport from Peatland to Marine Waters.

PubMed

Muller, François L L; Cuscov, Marco

2017-03-21

Blanket bogs contain vast amounts of Sphagnum-derived organic substances which can act as powerful chelators for dissolved iron and thus enhance its export to the coastal ocean. To investigate the variations in quantity and quality of these exports, adsorptive cathodic stripping voltammetry (CSV) was used to characterize the metal binding properties of molecular weight-fractionated dissolved organic matter (MW-fractionated DOM) in the catchment and coastal plume of a small peat-draining river over a seasonal cycle. Within the plume, both iron- and copper-binding organic ligands showed a linear, conservative distribution with increasing salinity, illustrating the high stability of peatland-derived humic substances (HS). Within the catchment, humic colloids lost up to 50% of their copper-binding capacity, expressed as a molar ratio to organic carbon, after residing for 1 week or more in the main reservoir of the catchment. Immediately downstream of the reservoir, the molar ratio [L 2 ]/[C org ], where L 2 was the second strongest copper-binding ligand, was 0.75 × 10 -4 when the reservoir residence time was 5 h but 0.34 × 10 -4 when it was 25 days. Residence time did not affect the carbon specific iron-binding capacity of the humic substances which was [L]/[C org ] = (0.80 ± 0.20) × 10 -2 . Our results suggest that the loss of copper-binding capacity with increasing residence time is caused by intracolloidal interactions between iron and HS during transit from peat soil to river mouth.

Synthesis of Copper Birnessite, Cu xMnO y·nH 2O with Crystallite Size Control: Impact of Crystallite Size on Electrochemistry

DOE PAGES

Li, Yue Ru; Marschilok, Amy C.; Takeuchi, Esther S.; ...

2015-11-24

This report describes the first detailed electrochemical examination of a series of copper birnessite samples under lithium-based battery conditions, allowing a structure/function analysis of the electrochemistry and related material properties. To obtain the series of copper birnessite samples, a novel synthetic approach for the preparation of copper birnessite, Cu xMnO y·nH 2O is reported. The copper content (x) in Cu xMnO y·nH 2O, 0.28 >= x >= 0.20, was inversely proportional to crystallite size, which ranged from 12 to 19 nm. The electrochemistry under lithium-based battery conditions showed that the higher copper content (x = 0.28) and small crystallite sizemore » (similar to 12 nm) sample delivered similar to 194 mAh/g, about 20% higher capacity than the low copper content (x = 0.22) and larger crystallite size (similar to 19 nm) material. In addition, Cu xMnO y·nH 2O displays quasi-reversible electrochemistry in magnesium based electrolytes, indicating that copper birnessite could be a candidate for future application in magnesium-ion batteries.« less

Bioaccessibility and Solubility of Copper in Copper-Treated Lumber

EPA Science Inventory

Micronized copper (MC)-treated lumber is a recent replacement for Chromated Copper Arsenate (CCA) and Ammonium Copper (AC)-treated lumbers; though little is known about the potential risk of copper (Cu) exposure from incidental ingestion of MC-treated wood. The bioaccessibility o...

Diffuse emission and control of copper in urban surface runoff.

PubMed

Boller, M A; Steiner, M

2002-01-01

Copper washed off from roofs and roads is considered to be a major contribution to diffuse copper pollution of urban environments. In order to guarantee sustainable protection of soils and water, the long-term strategy is to avoid or replace copper containing materials on roofs and fagades. Until achievement of this goal, a special adsorber system is suggested to control the diffuse copper fluxes by retention of copper by a mixture of granulated iron-hydroxide (GEH) and calcium carbonate. Since future stormwater runoff concepts are based on decentralised runoff infiltration into the underground, solutions are proposed which provide for copper retention in infiltration sites using GEH adsorption layers. The example of a large copper façade of which the runoff is treated in an adsorption trench reveals the first full-scale data on façade runoff and adsorber performance. During the first year of investigation average façade runoff concentrations in the range of 1-10 mg Cu/l are reduced by 96-99% in the adsorption ditch.

A CuNi bimetallic cathode with nanostructured copper array for enhanced hydrodechlorination of trichloroethylene (TCE).

PubMed

Liu, Bo; Zhang, Hao; Lu, Qi; Li, Guanghe; Zhang, Fang

2018-09-01

To address the challenges of low hydrodechlorination efficiency by non-noble metals, a CuNi bimetallic cathode with nanostructured copper array film was fabricated for effective electrochemical dechlorination of trichloroethylene (TCE) in aqueous solution. The CuNi bimetallic cathodes were prepared by a simple one-step electrodeposition of copper onto the Ni foam substrate, with various electrodeposition time of 5/10/15/20 min. The optimum electrodeposition time was 10 min when copper was coated as a uniform nanosheet array on the nickel foam substrate surface. This cathode exhibited the highest TCE removal, which was twice higher compared to that of the nickel foam cathode. At the same passed charge of 1080C, TCE removal increased from 33.9 ± 3.3% to 99.7 ± 0.1% with the increasing operation current from 5 to 20 mA cm -2 , while the normalized energy consumption decreased from 15.1 ± 1.0 to 2.6 ± 0.01 kWh log -1  m -3 . The decreased normalized energy consumption at a higher current density was due to the much higher removal efficiency at a higher current. These results suggest that CuNi cathodes prepared by simple electrodeposition method represent a promising and cost-effective approach for enhanced electrochemical dechlorination. Copyright © 2018 Elsevier B.V. All rights reserved.

Salivary levels of nickel, chromium, iron, and copper in patients treated with metal or esthetic fixed orthodontic appliances: A retrospective cohort study.

PubMed

Lages, Renata Bandeira; Bridi, Enrico Coser; Pérez, Carlos Alberto; Basting, Roberta Tarkany

2017-03-01

The purpose of this retrospective cohort study was to measure the salivary levels of nickel (Ni), chromium (Cr), iron (Fe) and copper (Cu) released from metal and esthetic fixed orthodontic appliances. Ninety patients were divided into three groups (n=30): control (those who had never undergone orthodontic treatment), metal appliance (stainless steel brackets and bands, and nitinol archwires) and esthetic appliance (polycarbonate brackets and tubes, and rhodium-coated nitinol archwires). Patients undergoing orthodontic treatment had used their appliances for periods between one and six months. Ni, Cr, Fe and Cu salivary concentrations were measured by the Total Reflection X-Ray Fluorescence technique. Kruskal-Wallis and Bonferroni-Dunn test showed that Ni (p=0.027) and Cr (p=0.040) concentrations were significantly higher for patients undergoing metallic orthodontic treatment than for the esthetic group. No significant difference regarding Ni and Cr (p=0.447) concentrations were observed between the metal and the control groups (p=0.464 and p=0.447, respectively) or between the esthetic and the control groups (p=0.698 and p=0.912, respectively). Ni and Cr concentrations were significantly influenced by the type of appliance used. Fe and Cu concentrations were not affected by the type or use of orthodontic appliances. Copyright © 2016 Elsevier GmbH. All rights reserved.

Microelectrodes Based investigation of the Impacts of Water Chemistry on Copper and Iron Corrosion

EPA Science Inventory

The effect of bulk drinking water quality on copper and iron pipe corrosion has been extensively studied. Despite past research, many have argued that bulk water quality does not necessarily reflect water quality near the water-metal interface and that such knowledge is necessary...

The determination of aluminum, copper, iron, and lead in glycol formulations by atomic absorption spectroscopy

NASA Technical Reports Server (NTRS)

1977-01-01

Initial screening tests and the results obtained in developing procedures to determine Al, Cu, Fe, and Pb in glycol formulations are described. Atomic absorption completion was selected for Cu, Fe and Pb, and after comparison with emission spectroscopy, was selected for Al also. Before completion, carbon, iron, and lead are extracted with diethyl dithio carbamate (DDC) into methyl isobutyl ketone (MIBK). Aluminum was also extracted into MIBK using 8-hydroxyquinoline as a chelating agent. As little as 0.02 mg/l carbon and 0.06 mg/l lead or iron may be determined in glycol formulations. As little as 0.3 mg/l aluminum may be determined.

Copper-tuned magnetic order and excitations in iron-based superconductors Fe1+yTe1-xSex

NASA Astrophysics Data System (ADS)

Wen, Jinsheng; Xu, Zhijun; Xu, Guangyong; Lumsden, Mark; Matsuda, Masaaki; Valdivia, Patrick; Bourret, Edith; Lee, Dunghai; Gu, Genda; Tranquada, John; Birgeneau, Robert

2012-02-01

We report neutron scattering results on the Cu-substitution effects in the iron-based superconductors, Fe1+yTe1-xSex. In the parent compound, it is found that Cu drives the low-temperature magnetic ground state from long-range commensurate antiferromagnetic order in Fe1.06TeCu0.04 to short-range incommensurate order in FeTeCu0.1. In the former sample, the structural and magnetic ordering temperature is 40 K; in FeTeCu0.1, the structural phase transition is not obvious and a transition to the spin-glass state is found at 22 K. Cu suppresses superconductivity in FeTe0.5Se0.5---Tc is reduced to 7 K with a 2% Cu doping, and no superconductivity is found in the 10% Cu-doped sample. In the meantime, the intensity and energy of the resonance mode are suppressed in the 2% Cu-doped sample, while there is no resonance in the non-superconducting sample. Besides, the low-temperature magnetic excitation spectra are distinct for these two samples, with the superconducting one having an ``hour-glass" shape and the other one having a ``waterfall" shape. Our results provide further insights on the interplay between magnetism and superconductivity in the iron-based superconductors.

A New Test of Copper and Zinc Abundances in Late-Type Stars Using Cu II and Zn II lines in the Near-Ultraviolet

NASA Astrophysics Data System (ADS)

Roederer, Ian

2017-08-01

The copper (Cu, Z = 29) and zinc (Zn, Z = 30) abundances found in late-type stars provide critical constraints on models that predict the yields of massive star supernovae, hypernovae, Type Ia supernovae, and AGB stars, which are essential ingredients in Galactic chemical evolution models. Furthermore, Zn is commonly used to compare the abundance of iron-group elements in the gas phase in high-redshift DLA systems with metallicities in Local Group stars. It is thus important that the observational Cu and Zn abundances in stars are correct. My proposed archive study will address this issue by using archive STIS spectra of 14 stars to provide the first systematic observational tests of non-LTE calculations of Cu and Zn line formation in late-type stars. The non-LTE calculations predict that all LTE [Cu/Fe] abundance ratios presently found in the literature are systematically lower than the true ratios found in stars. The non-LTE calculations for Zn predict that the LTE values in the literature may be systematically overestimated in low-metallicity stars. The LTE abundances of Cu and Zn are derived from Cu I and Zn I lines. The key advance enabled by the use of NUV spectra is the detection of several lines of Cu II and Zn II, which cannot be detected in the optical or infrared. Cu II and Zn II are largely immune to non-LTE effects in the atmospheres of late-type stars. The metallicities of the 14 stars with NUV spectra span -2.6 < [Fe/H] < -0.1, which covers the range of most Cu and Zn abundances reported in the literature. The proposed study will allow me to test the non-LTE calculations and calibrate the stellar abundances.

Synthesis and structural characterisation of iron(II) and copper(II) diphosphates containing flattened metal oxotetrahedra

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keates, Adam C.; Wang, Qianlong; Weller, Mark T., E-mail: m.t.weller@bath.ac.uk

2014-02-15

Single crystal and bulk polycrystalline forms of K{sub 2}MP{sub 2}O{sub 7} (M=Fe(II), Cu(II)) have been synthesised and their structures determined from single crystal X-ray diffraction data. Both compounds crystallize in the tetragonal system, space group P-42{sub 1}m. Their structures are formed from infinite sheets of linked oxopolyhedra of the stoichiometry [MP{sub 2}O{sub 7}]{sup 2−} with potassium cations situated between the layers. The MO{sub 4} tetrahedra share oxygen atoms with [P{sub 2}O{sub 7}]{sup 4−} diphosphate groups and the potassium ions have KO{sub 8} square prismatic geometry. In both compounds the M(II) centre has an unusual strongly flattened, tetrahedral coordination to oxygen,more » as a result of the Jahn–Teller (JT) effect for the high spin d{sup 6} Fe(II) and p-orbital mixing or a second order JT effect for d{sup 9} Cu(II) centres in four fold coordination. The uncommon transition metal ion environments found in these materials are reflected in their optical absorption spectra and magnetism data. - Graphical abstract: The structures of the tetragonal polymorphs of K{sub 2}MP{sub 2}O{sub 7}, M=Cu(II), Fe(II), consist of infinite sheets of stoichiometry [MP{sub 2}O{sub 7}]{sup 2−}, formed from linked pyrophosphate groups and MO{sub 4} tetrahedra, separated by potassium ions. In both compounds the unusual tetrahedral coordination of the M(II) centre is strongly flattened as a result of Jahn–Teller (JT) effects for high spin, d{sup 6} Fe(II) and p-orbital mixing and second-order JT effects for d{sup 9} Cu(II). Display Omitted - Highlights: • Tetrahedral copper and iron(II) coordinated by oxygen. • New layered phosphate structure. • Jahn–Teller and d{sup 10} distorted coordinations.« less

Crystallization of copper metaphosphate glass

NASA Technical Reports Server (NTRS)

Bae, Byeong-Soo; Weinberg, Michael C.

1993-01-01

The effect of the valence state of copper in copper metaphosphate glass on the crystallization behavior and glass transition temperature has been investigated. The crystallization of copper metaphosphate is initiated from the surface and its main crystalline phase is copper metaphosphate (Cu(PO)3),independent of the (Cu sup 2+)/(Cu(total)). However, the crystal morphology, the relative crystallization rates, and their temperature dependences are affected by the (Cu sup 2+)/(Cu (total)) ratio in the glass. On the other hand, the totally oxidized glass crystallizes from all over the surface. The relative crystallization rate of the reduced glass to the totally oxidized glass is large at low temperature, but small at high temperature. The glass transition temperature of the glass increases as the (Cu sup 2+)/(Cu(total)) ratio is raised. It is also found that the atmosphere used during heat treatment does not influence the crystallization of the reduced glass, except for the formation of a very thin CuO surface layer when heated in air.

Estimation of the molar absorption coefficient of copper salicylate within the spectral range 300-350 nm

NASA Astrophysics Data System (ADS)

Lavrik, N. L.; Mulloev, N. U.

2017-12-01

Additional absorption was detected in absorption spectra within the range 300-350 nm after addition of copper sulfate CuSO4(aq) to a solution of sodium salicylate NaНSal (рН = 7.8). The additional maximum absorption was observed at 320 nm. Assuming that the additional absorption depends on the formation of copper salicylate CuSal, the molar absorption coefficient εCuSal of this complex was determined to be (3.8 ± 0.02) · 103 М- 1 сm- 1. This value is almost equal to that of monoanion HSal-, εHSal - = (3.6 ± 0.04) · 103 М- 1 сm- 1, and is 2.5 times as much as εFe3 + HSal - = (1.55 ± 0.05) · 103 М- 1 сm- 1 for iron salicylate. The difference in εCuSal and εFe3 + HSal - is due to the difference in the initial electron states of Cu2 + and Fe3 + ions that have the d9 and d5 configurations, respectively.

Non-enzymatic glucose sensor based on electrodeposited copper on carbon paste electrode (Cu/CPE)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nurani, Dita Arifa, E-mail: d.arifa@sci.ui.ac.id; Wibowo, Rahmat; Fajri, Iqbal Farhan El

The development of non-enzymatic glucose sensor has much attention due to their applications in glucose monitoring. In this research, copper oxide is used as a non-enzymatic glucose sensor by oxidizing glucose to gluconolactone. Copper was electrodeposited on Carbon paste electrode (CPE) at constant potential. The experimental condition was varied in electrodeposition of Cu with the following parameters: Electrodeposition time 60 s, 120 s and 180 s and potential reduction -0.166 V, -0.266 V and -0.366 V. The effective performance of these working electrodes in sensing glucose was investigated. The Cu/CPE which used -0.366 V potential reduction and 120 s electrodeposition time shows the bestmore » performance. The amperometric response current in concentration range 1.6-62.5 mM of glucose gives the good linearity R{sup 2} = 0.9988, low detection limit 0.6728 mM and high sensitivity 1183.59 µA mM{sup −1}cm{sup −2}. Furthermore this sensor exhibited a good repeatability with %RSD = 1.31% (n=10) and high stability with %RSD = 1.51% (n=5 days). The homogeneity of Cu particles on CPE was investigated by Scanning Electron Microscope (SEM).« less

The Variations of Glycolysis and TCA Cycle Intermediate Levels Grown in Iron and Copper Mediums of Trichoderma harzianum.

PubMed

Tavsan, Zehra; Ayar Kayali, Hulya

2015-05-01

The efficiency of optimal metabolic function by microorganism depends on various parameters, especially essential metal supplementation. In the present study, the effects of iron and copper metals on metabolism were investigated by determination of glycolysis and tricarboxylic acid (TCA) cycle metabolites' levels with respect to the metal concentrations and incubation period in Trichoderma harzianum. The pyruvate and citrate levels of T. harzianum increased up to 15 mg/L of copper via redirection of carbon flux though glycolysis by suppression of pentose phosphate pathway (PPP). However, the α-ketoglutarate levels decreased at concentration higher than 5 mg/L of copper to overcome damage of oxidative stress. The fumarate levels correlated with the α-ketoglutarate levels because of substrate limitation. Besides, in T. harzianum cells grown in various concentrations of iron-containing medium, the intracellular pyruvate, citrate, and α-ketoglutarate levels showed positive correlation with iron concentration due to modifying of expression of glycolysis and TCA cycle enzymes via a mechanism involving cofactor or allosteric regulation. However, as a result of consuming of prior substrates required for fumarate production, its levels rose up to 10 mg/L.

Synthesis of graphene oxide-copper molybdate (GO-CuM) nanocomposites for photocatalytic application

NASA Astrophysics Data System (ADS)

Singh, Gajendar; Bhargava, V. Sai; Sharma, Manu

2018-05-01

Transition metal molybdates (TMBs) MMoO4 (M=Ni, Cu, Fe, Zn, Co, etc.) based nanocomposites have been considered as remarkable materials in the field of electronics, optics, catalysis, supercapicitors and energy storage devices. Nanocomposites of TMBs with graphene oxide have also been chosen as an effective material in photocatalytic application. GO-CuM nanocomposites were synthesized by ultra-sonication method at RT, followed by reflux route for preparation of CuM and GO by modified Hemmer's method. As prepared nanocomposites were characterized using analytical techniques such as PXRD, SEM, FT-IR and UV-Visible spectroscopy. The enhanced photocatalytic activity of Methylene blue (MB) dye was observed by GO-CuM nanocomposites as compared to pure copper molybdate. GO-CuM nanocomposites show high photodegradation rate (0.094 min-1) whereas CuM was degraded only 30 % with the rate of 0.0029 min-1. The high photocatalytic efficiency is due to the presence of graphene oxide that helps to delay the charge recombination in photocatalytic reaction The effect of the different amount of graphene oxide on the photocatalytic activity of as prepared photocatalyst has also been investigated.

Silencing the Menkes Copper-Transporting ATPase (Atp7a) Gene in Rat Intestinal Epithelial (IEC-6) Cells Increases Iron Flux via Transcriptional Induction of Ferroportin 1 (Fpn1)123

PubMed Central

Gulec, Sukru; Collins, James F.

2014-01-01

The Menkes copper-transporting ATPase (Atp7a) gene is induced in rat duodenum during iron deficiency, consistent with copper accumulation in the intestinal mucosa and liver. To test the hypothesis that ATP7A influences intestinal iron metabolism, the Atp7a gene was silenced in rat intestinal epithelial (IEC-6) cells using short hairpin RNA (shRNA) technology. Perturbations in intracellular copper homeostasis were noted in knockdown cells, consistent with the dual roles of ATP7A in pumping copper into the trans-Golgi (for cuproenzyme synthesis) and exporting copper from cells. Intracellular iron concentrations were unaffected by Atp7a knockdown. Unexpectedly, however, vectorial iron (59Fe) transport increased (∼33%) in knockdown cells grown in bicameral inserts and increased further (∼70%) by iron deprivation (compared with negative control shRNA-transfected cells). Additional experiments were designed to elucidate the molecular mechanism of increased transepithelial iron flux. Enhanced iron uptake by knockdown cells was associated with increased expression of a ferrireductase (duodenal cytochrome b) and activity of a cell-surface ferrireductase. Increased iron efflux from knockdown cells was likely mediated via transcriptional activation of the ferroportin 1 gene (by an unknown mechanism). Moreover, Atp7a knockdown significantly attenuated expression of an iron oxidase [hephaestin (HEPH); by ∼80%] and membrane ferroxidase activity (by ∼50%). Cytosolic ferroxidase activity, however, was retained in knockdown cells (75% of control cells), perhaps compensating for diminished HEPH activity. This investigation has thus documented alterations in iron homeostasis associated with Atp7a knockdown in enterocyte-like cells. Alterations in copper transport, trafficking, or distribution may underlie the increase in transepithelial iron flux noted when ATP7A activity is diminished. PMID:24174620

Role of copper oxides in contact killing of bacteria.

PubMed

Hans, Michael; Erbe, Andreas; Mathews, Salima; Chen, Ying; Solioz, Marc; Mücklich, Frank

2013-12-31

The potential of metallic copper as an intrinsically antibacterial material is gaining increasing attention in the face of growing antibiotics resistance of bacteria. However, the mechanism of the so-called "contact killing" of bacteria by copper surfaces is poorly understood and requires further investigation. In particular, the influences of bacteria-metal interaction, media composition, and copper surface chemistry on contact killing are not fully understood. In this study, copper oxide formation on copper during standard antimicrobial testing was measured in situ by spectroscopic ellipsometry. In parallel, contact killing under these conditions was assessed with bacteria in phosphate buffered saline (PBS) or Tris-Cl. For comparison, defined Cu2O and CuO layers were thermally generated and characterized by grazing incidence X-ray diffraction. The antibacterial properties of these copper oxides were tested under the conditions used above. Finally, copper ion release was recorded for both buffer systems by inductively coupled plasma atomic absorption spectroscopy, and exposed copper samples were analyzed for topographical surface alterations. It was found that there was a fairly even growth of CuO under wet plating conditions, reaching 4-10 nm in 300 min, but no measurable Cu2O was formed during this time. CuO was found to significantly inhibit contact killing, compared to pure copper. In contrast, thermally generated Cu2O was essentially as effective in contact killing as pure copper. Copper ion release from the different surfaces roughly correlated with their antibacterial efficacy and was highest for pure copper, followed by Cu2O and CuO. Tris-Cl induced a 10-50-fold faster copper ion release compared to PBS. Since the Cu2O that primarily forms on copper under ambient conditions is as active in contact killing as pure copper, antimicrobial objects will retain their antimicrobial properties even after oxide formation.

Comparison between micro- and nanosized copper oxide and water soluble copper chloride: interrelationship between intracellular copper concentrations, oxidative stress and DNA damage response in human lung cells.

PubMed

Strauch, Bettina Maria; Niemand, Rebecca Katharina; Winkelbeiner, Nicola Lisa; Hartwig, Andrea

2017-08-01

Nano- and microscale copper oxide particles (CuO NP, CuO MP) are applied for manifold purposes, enhancing exposure and thus the potential risk of adverse health effects. Based on the pronounced in vitro cytotoxicity of CuO NP, systematic investigations on the mode of action are required. Therefore, the impact of CuO NP, CuO MP and CuCl 2 on the DNA damage response on transcriptional level was investigated by quantitative gene expression profiling via high-throughput RT-qPCR. Cytotoxicity, copper uptake and the impact on the oxidative stress response, cell cycle regulation and apoptosis were further analysed on the functional level. Cytotoxicity of CuO NP was more pronounced when compared to CuO MP and CuCl 2 in human bronchial epithelial BEAS-2B cells. Uptake studies revealed an intracellular copper overload in the soluble fractions of both cytoplasm and nucleus, reaching up to millimolar concentrations in case of CuO NP and considerably lower levels in case of CuO MP and CuCl 2 . Moreover, CuCl 2 caused copper accumulation in the nucleus only at cytotoxic concentrations. Gene expression analysis in BEAS-2B and A549 cells revealed a strong induction of uptake-related metallothionein genes, oxidative stress-sensitive and pro-inflammatory genes, anti-oxidative defense-associated genes as well as those coding for the cell cycle inhibitor p21 and the pro-apoptotic Noxa and DR5. While DNA damage inducible genes were activated, genes coding for distinct DNA repair factors were down-regulated. Modulation of gene expression was most pronounced in case of CuO NP as compared to CuO MP and CuCl 2 and more distinct in BEAS-2B cells. GSH depletion and activation of Nrf2 in HeLa S3 cells confirmed oxidative stress induction, mainly restricted to CuO NP. Also, cell cycle arrest and apoptosis induction were most distinct for CuO NP. The high cytotoxicity and marked impact on gene expression by CuO NP can be ascribed to the strong intracellular copper ion release, with subsequent

Surface Modification of C17200 Copper-Beryllium Alloy by Plasma Nitriding of Cu-Ti Gradient Film

NASA Astrophysics Data System (ADS)

Zhu, Y. D.; Yan, M. F.; Zhang, Y. X.; Zhang, C. S.

2018-03-01

In the present work, a copper-titanium film of gradient composition was firstly fabricated by the dual magnetron sputtering through power control and plasma nitriding of the film was then conducted to modify C17200 Cu alloy. The results showed that the prepared gradient Cu-Ti film by magnetron sputtering was amorphous. After plasma nitriding at 650 °C, crystalline Cu-Ti intermetallics appeared in the multi-phase coating, including CuTi2, Cu3Ti, Cu3Ti2 and CuTi. Moreover, even though the plasma nitriding duration of the gradient Cu-Ti film was only 0.5 h, the mechanical properties of the modified Cu surface were obviously improved, with the surface hardness enhanced to be 417 HV0.01, the wear rate to be 0.32 × 10-14 m3/Nm and the friction coefficient to be 0.075 at the load of 10 N, which are all more excellent than the C17200 Cu alloy. In addition, the wear mechanism also changed from adhesion wear for C17200 Cu substrate to abrasive wear for the modified surface.

Isolation of the Copper Redox Steps in the Standard Selective Catalytic Reduction on Cu-SSZ-13

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paolucci, Christopher; Verma, Anuj A.; Bates, Shane A.

2014-10-27

Operando X-ray absorption experiments and density functional theory (DFT) calculations are reported that elucidate the role of copper redox chemistry in the selective catalytic reduction (SCR) of NO over Cu-exchanged SSZ-13. Catalysts prepared to contain only isolated, exchanged CuII ions evidence both CuII and CuI ions under standard SCR conditions at 473 K. Reactant cutoff experiments show that NO and NH3 together are necessary for CuII reduction to CuI. DFT calculations show that NO-assisted NH3 dissociation is both energetically favorable and accounts for the observed CuII reduction. The calculations predict in situ generation of Brønsted sites proximal to CuI uponmore » reduction, which we quantify in separate titration experiments. Both NO and O2 are necessary for oxidation of CuI to CuII, which DFT suggests to occur by a NO2 intermediate. Reaction of Cu-bound NO2 with proximal NH4 + completes the catalytic cycle. N2 is produced in both reduction and oxidation half-cycles.« less

Isolation of the Copper Redox Steps in the Standard Selective Catalytic Reduction on Cu-SSZ-13

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paolucci, Christopher; Verma, Anuj A.; Bates, Shane A.

2014-09-12

Operando X-ray absorption experiments and density functional theory (DFT) calculations are reported that elucidate the role of copper redox chemistry in the selective catalytic reduction (SCR) of NO over Cu-exchanged SSZ-13. Catalysts prepared to contain only isolated, exchanged CuII ions evidence both CuII and CuI ions under standard SCR conditions at 473 K. Reactant cutoff experiments show that NO and NH3 together are necessary for CuII reduction to CuI. DFT calculations show that NO-assisted NH3 dissociation is both energetically favorable and accounts for the observed CuII reduction. The calculations predict in situ generation of Brønsted sites proximal to CuI uponmore » reduction, which we quantify in separate titration experiments. Both NO and O2 are necessary for oxidation of CuI to CuII, which DFT suggests to occur by a NO2 intermediate. Reaction of Cu-bound NO2 with proximal NH4 + completes the catalytic cycle. N2 is produced in both reduction and oxidation half-cycles.« less

Green synthesis of copper oxide (CuO) nanoparticles using banana peel extract and their photocatalytic activities

NASA Astrophysics Data System (ADS)

Aminuzzaman, Mohammod; Kei, Leong Mei; Liang, Wong Hong

2017-04-01

Copper oxide nanoparticles (CuO NPs) are interesting class of materials having multifunctional properties with promising applications in the areas of catalysts, gas sensors, batteries, magnetic storage media, solar energy, superconductors etc. Thus synthesis of CuO NPs has attracted tremendous interest to scientists and researchers Herein, we reported a green and simple method for biosynthesizing CuO NPs using banana peel extract as reducing and stabilizing agent. XRD, EDX, FE-SEM, FTIR have been used for characterization of biosynthesized CuO NPs. The results indicating that the CuO NPs synthesized by banana peel extract have high purity and the average particles size is 60 nm. The photocatalytic activity of the CuO NPs has been investigated by degradation of Congo red (CR) dye under solar irradiation. The extent of CR dye degradation by CuO NPs is monitored by using a UV-visible spectrophotometer. Due to the smaller size and high purity, the biosynthesized CuO NPs showed an excellent photocatlytic activity.

Copper-based alloys, crystallographic and crystallochemical parameters of alloys in binary systems Cu-Me (Me=Co, Rh, Ir, Cu, Ag, Au, Ni, Pd, Pt)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Porobova, Svetlana, E-mail: porobova.sveta@yandex.ru; Loskutov, Oleg, E-mail: lom58@mail.ru; Markova, Tat’jana, E-mail: patriot-rf@mail.ru

2016-01-15

The article presents the results of the analysis of phase equilibrium of ordered phases in binary systems based on copper Cu- Me (where Me - Co, Rh, Ir, Ag, Au, Ni, Pd, Pt) to find correlations of crystallochemical and crystallographic factors. It is established that the packing index in disordered solid solutions in binary systems based on copper is close to the value of 0.74 against the background of an insignificant deviation of atomic volumes from the Zen’s law.

Electromigration induced high fraction of compound formation in SnAgCu flip chip solder joints with copper column

NASA Astrophysics Data System (ADS)

Xu, Luhua; Han, Jung-Kyu; Liang, Jarrett Jun; Tu, K. N.; Lai, Yi-Shao

2008-06-01

To overcome the effect of current crowding on electromigration-induced pancake-type void formation in flip chip solder joints, two types of Cu column in 90μm flip chip SnAgCu solder joints have been studied. They were (1) the solder contacts the Cu column at bottom and side walls and (2) the solder wets only the bottom surface of the copper column. With a current density of 1.6×104A/cm2 at 135°C, no failure was detected after 1290h. However, the resistance increased by about 10% due to the formation of a large fraction of intermetallic compounds. We found that electromigration has accelerated the consumption rate of copper column and converted almost the entire solder joint into intermetallic compound. Mechanically, drop impact test indicates a brittle fracture failure in the intermetallic. The electromigration critical product for the intermetallic is discussed.

The effect of copper doping on martensite shear stress in porous TiNi(Mo,Fe,Cu) alloys

NASA Astrophysics Data System (ADS)

Khodorenko, V. N.; Kaftaranova, M. I.; Gunther, V. E.

2015-03-01

The properties of alloys based on porous nickel-titanium (TiNi) with copper additives have been studied. It is established that the copper doping of porous TiNi(Mo,Fe,Cu) alloys fabricated by the method of self-propagating high-temperature synthesis leads to a significant decrease in the martensite shear stress (below 30 MPa). Low values of the martensite shear stress (σmin) in copper-doped TiNi-based alloys allows medical implants of complex shapes to be manufactured for various purposes, including oral surgery. The optimum concentration of copper additives (within 3-6 at %) has been determined that ensures high performance characteristics of TiNi-based porous alloys for medical implants.

Cu-doped ZnO nanorod arrays: the effects of copper precursor and concentration

PubMed Central

2014-01-01

Cu-doped ZnO nanorods have been grown at 90°C for 90 min onto a quartz substrate pre-coated with a ZnO seed layer using a hydrothermal method. The influence of copper (Cu) precursor and concentration on the structural, morphological, and optical properties of ZnO nanorods was investigated. X-ray diffraction analysis revealed that the nanorods grown are highly crystalline with a hexagonal wurtzite crystal structure grown along the c-axis. The lattice strain is found to be compressive for all samples, where a minimum compressive strain of −0.114% was obtained when 1 at.% Cu was added from Cu(NO3)2. Scanning electron microscopy was used to investigate morphologies and the diameters of the grown nanorods. The morphological properties of the Cu-doped ZnO nanorods were influenced significantly by the presence of Cu impurities. Near-band edge (NBE) and a broad blue-green emission bands at around 378 and 545 nm, respectively, were observed in the photoluminescence spectra for all samples. The transmittance characteristics showed a slight increase in the visible range, where the total transmittance increased from approximately 80% for the nanorods doped with Cu(CH3COO)2 to approximately 90% for the nanorods that were doped with Cu(NO3)2. PMID:24855460

Copper isotopic zonation in the Northparkes porphyry Cu-Au deposit, SE Australia

NASA Astrophysics Data System (ADS)

Li, Weiqiang; Jackson, Simon E.; Pearson, Norman J.; Graham, Stuart

2010-07-01

Significant, systematic Cu isotopic variations have been found in the Northparkes porphyry Cu-Au deposit, NSW, Australia, which is an orthomagmatic porphyry Cu deposit. Copper isotope ratios have been measured in sulfide minerals (chalcopyrite and bornite) by both solution and laser ablation multi-collector inductively coupled plasma-mass spectrometry (MC-ICP-MS). The results from both methods show a variation in δ 65Cu of hypogene sulfide minerals of greater than 1‰ (relative to NIST976). Significantly, the results from four drill holes through two separate ore bodies show strikingly similar patterns of Cu isotope variation. The patterns are characterized by a sharp down-hole decrease from up to 0.8‰ (0.29 ± 0.56‰, 1 σ, n = 20) in the low-grade peripheral alteration zones (phyllic-propylitic alteration zone) to a low of ˜-0.4‰ (-0.25 ± 0.36‰, 1 σ, n = 30) at the margins of the most mineralized zones (Cu grade >1 wt%). In the high-grade cores of the systems, the compositions are more consistent at around 0.2‰ (0.19 ± 0.14‰, 1 σ, n = 40). The Cu isotopic zonation may be explained by isotope fractionation of Cu between vapor, solution and sulfides at high temperature, during boiling and sulfide precipitation processes. Sulfur isotopes also show an isotopically light shell at the margins of the high-grade ore zones, but these are displaced from the low δ 65Cu shells, such that there is no correlation between the Cu and S isotope signatures. Fe isotope data do not show any discernable variation along the drill core. This work demonstrates that Cu isotopes show a large response to high-temperature porphyry mineralizing processes, and that they may act as a vector to buried mineralization.

Targeting copper(II)-induced oxidative stress and the acetylcholinesterase system in Alzheimer's disease using multifunctional tacrine-coumarin hybrid molecules.

PubMed

Hamulakova, Slavka; Poprac, Patrik; Jomova, Klaudia; Brezova, Vlasta; Lauro, Peter; Drostinova, Lenka; Jun, Daniel; Sepsova, Vendula; Hrabinova, Martina; Soukup, Ondrej; Kristian, Pavol; Gazova, Zuzana; Bednarikova, Zuzana; Kuca, Kamil; Valko, Marian

2016-08-01

Alzheimer's disease is a multifactorial disease that is characterized mainly by Amyloid-β (A-β) deposits, cholinergic deficit and extensive metal (copper, iron)-induced oxidative stress. In this work we present details of the synthesis, antioxidant and copper-chelating properties, DNA protection study, cholinergic activity and amyloid-antiaggregation properties of new multifunctional tacrine-7-hydroxycoumarin hybrids. The mode of interaction between copper(II) and hybrids and interestingly, the reduction of Cu(II) to Cu(I) species (for complexes Cu-5e-g) were confirmed by EPR measurements. EPR spin trapping on the model Fenton reaction, using 5,5-dimethyl-1-pyrroline N-oxide (DMPO) as a spin trap, demonstrated a significantly suppressed formation of hydroxyl radicals for the Cu-5e complex in comparison with free copper(II). This suggests that compound 5e upon coordination to free copper ion prevents the Cu(II)-catalyzed decomposition of hydrogen peroxide, which in turn may alleviate oxidative stress-induced damage. Protective activity of hybrids 5c and 5e against DNA damage in a Fenton system (copper catalyzed) was found to be in excellent agreement with the EPR spin trapping study. Compound 5g was the most effective in the inhibition of acetylcholinesterase (hAChE, IC50=38nM) and compound 5b was the most potent inhibitor of butyrylcholinesterase (hBuChE, IC50=63nM). Compound 5c was the strongest inhibitor of A-β1-40 aggregation, although a significant inhibition (>50%) was detected for compounds 5b, 5d, 5e and 5g. Collectively, these results suggest that the design and investigation of multifunctional agents containing along with the acetylcholinesterase inhibitory segment also an antioxidant moiety capable of alleviating metal (copper)-induced oxidative stress, may be of importance in the treatment of Alzheimer's disease. Copyright © 2016 Elsevier Inc. All rights reserved.

Copper Status of Exposed Microorganisms Influences Susceptibility to Metallic Nanoparticles

PubMed Central

Reyes, Vincent C.; Spitzmiller, Melissa R.; Hong-Hermesdorf, Anne; Kropat, Janette; Damoiseaux, Robert D.; Merchant, Sabeeha S.; Mahendra, Shaily

2017-01-01

Although interactions of metallic nanoparticles (NP) with various microorganisms have been previously explored, few studies have examined how metal sensitivity impacts NP toxicity. Herein, we investigated the effects of copper nanoparticles’ (Cu-NPs) exposure to the model alga, Chlamydomonas reinhardtii, in the presence and absence of the essential micronutrient copper. The toxic ranges for Cu-NPs and the ionic control, CuCl2, were determined using a high-throughput ATP-based fluorescence assay. Cu-NPs caused similar mortality in copper-replete and copper-deplete cells (IC50: 14–16 mg/L), but were less toxic than the ionic control, CuCl2 (IC50: 7 mg/L). Using this concentration range, we assessed Cu-NP impacts to cell morphology, copper accumulation, chlorophyll content, and expression of stress genes under both copper supply states. Osmotic swelling, membrane damage, and chloroplast and organelle disintegration were observed by transmission electron microscopy at both conditions. Despite these similarities, copper-deplete cells showed greater accumulation of loosely bound and tightly bound copper after exposure to Cu-NPs. Furthermore, copper-replete cells experienced greater loss of chlorophyll content, 19 % for Cu-NPs, compared to only an 11% net decrease in copper-deplete cells. The tightly bound copper was bioavailable as assessed by reverse-transcriptase quantitative PCR analysis of CYC6, a biomarker for Cu-deficiency. The increased resistance of copper-deplete cells to Cu-NPs suggests that these cells potentially metabolize excess Cu-NPs or better manage sudden influxes of ions. Our findings recommend that toxicity assessments must account for the nutritional status of impacted organisms and use toxicity models based on estimations of the bioavailable fractions. PMID:26387648

Biodistribution and radiation dosimetry of [64Cu]copper dichloride: first-in-human study in healthy volunteers.

PubMed

Avila-Rodriguez, M A; Rios, C; Carrasco-Hernandez, J; Manrique-Arias, J C; Martinez-Hernandez, R; García-Pérez, F O; Jalilian, A R; Martinez-Rodriguez, E; Romero-Piña, M E; Diaz-Ruiz, A

2017-12-12

In recent years, Copper-64 (T 1/2  = 12.7 h) in the chemical form of copper dichloride ([ 64 Cu]CuCl 2 ) has been identified as a potential agent for PET imaging and radionuclide therapy targeting the human copper transporter 1, which is overexpressed in a variety of cancer cells. Limited human biodistribution and radiation dosimetry data is available for this tracer. The aim of this research was to determine the biodistribution and estimate the radiation dosimetry of [ 64 Cu]CuCl 2 , using whole-body (WB) PET scans in healthy volunteers. Six healthy volunteers were included in this study (3 women and 3 men, mean age ± SD, 54.3 ± 8.6 years; mean weight ± SD, 77.2 ± 12.4 kg). After intravenous injection of the tracer (4.0 MBq/kg), three consecutive WB emission scans were acquired at 5, 30, and 60 min after injection. Additional scans were acquired at 5, 9, and 24 h post-injection. Low-dose CT scan without contrast was used for anatomic localization and attenuation correction. OLINDA/EXM software was used to calculate human radiation doses using the reference adult model. The highest uptake was in the liver, followed by lower and upper large intestine walls, and pancreas, in descending order. Urinary excretion was negligible. The critical organ was liver with a mean absorbed dose of 310 ± 67 μGy/MBq for men and 421 ± 56 μGy/MBq for women, while the mean WB effective doses were 51.2 ± 3.0 and 61.8 ± 5.2 μSv/MBq for men and women, respectively. To the best of our knowledge, this is the first report on biodistribution and radiation dosimetry of [ 64 Cu]CuCl 2 in healthy volunteers. Measured absorbed doses and effective doses are higher than previously reported doses estimated with biodistribution data from patients with prostate cancer, a difference that could be explained not just due to altered biodistribution in cancer patients compared to healthy volunteers but most likely due to the differences in the analysis

Effect of the metals iron, copper and silver on fluorobenzene biodegradation by Labrys portucalensis.

PubMed

Moreira, Irina S; Amorim, Catarina L; Carvalho, Maria F; Ferreira, António C; Afonso, Carlos M; Castro, Paula M L

2013-04-01

Organic and metallic pollutants are ubiquitous in the environment. Many metals are reported to be toxic to microorganisms and to inhibit biodegradation. The effect of the metals iron, copper and silver on the metabolism of Labrys portucalensis F11 and on fluorobenzene (FB) biodegradation was examined. The results indicate that the addition of 1 mM of Fe(2+) to the culture medium has a positive effect on bacterial growth and has no impact in the biodegradation of 1 and 2 mM of FB. The presence of 1 mM of Cu(2+) was found to strongly inhibit the growth of F11 cultures and to reduce the biodegradation of 1 and 2 mM of FB to ca. 50 %, with 80 % of stoichiometrically expected fluoride released. In the experiments with resting cells, the FB degraded (from 2 mM supplied) was reduced ca. 20 % whereas the fluoride released was reduced to 45 % of that stoichiometrically expected. Ag(+) was the most potent inhibitor of FB degradation. In experiments with growing cells, the addition of 1 mM of Ag(+) to the culture medium containing 1 and 2 mM of FB resulted in no fluoride release, whereas FB degradation was only one third of that observed in control cultures. In the experiments with resting cells, the addition of Ag(+) resulted in 25 % reduction in substrate degradation and fluoride release was only 20 % of that stoichiometrically expected. The accumulation of catechol and 4-fluorocatechol in cultures supplemented with Cu(2+) or Ag(+) suggest inhibition of the key enzyme of FB metabolism-catechol 1,2-dioxygenase.

Optical and electrical stability of viral-templated copper sulfide (Cu1.8S) films

NASA Astrophysics Data System (ADS)

Shahriar Zaman, Mohammed; Bernard Grajeda, Gabriel; Haberer, Elaine D.

2014-04-01

The optical and electrical stabilities of viral-templated non-stoichiometric copper sulfide, digenite (Cu1.8S) films were investigated. The films were composed of large agglomerates of randomly aligned Cu1.8S-coated M13 filamentous phage. Free carrier optical absorption associated with localized surface plasmon resonance (LSPR) was observed in the near infrared spectral region, and the films were electrically active, displaying a linear current-voltage relationship. Under ambient conditions, the magnitude of the LSPR absorption increased, following a power law relationship with time, and the electrical resistance of viral-templated films decreased significantly. In contrast, the resistance of films stored under low oxygen, low humidity conditions experienced a smaller reduction in electrical resistance. Changes in optical and electrical film properties under ambient conditions were associated with an increase in free carrier concentration within the copper chalcogenide material due to oxygen exposure. X-ray photoelectron spectroscopy was used to relate this increase in free carrier concentration to compositional changes on the viral-templated material surface.

Comparison and distribution of copper oxide nanoparticles and copper ions in activated sludge reactors.

PubMed

Zhang, Dongqing; Trzcinski, Antoine P; Oh, Hyun-Suk; Chew, Evelyn; Tan, Soon Keat; Ng, Wun Jern; Liu, Yu

2017-05-12

Copper oxide nanoparticles (CuO NPs) are being increasingly applied in the industry which results inevitably in the release of these materials into the hydrosphere. In this study, simulated waste-activated sludge experiments were conducted to investigate the effects of Copper Oxide NPs at concentrations of 0.1, 1, 10 and 50 mg/L and to compare it with its ionic counterpart (CuSO 4 ). It was found that 0.1 mg/L of CuO NPs had negligible effects on Chemical Oxygen Demand (COD) and ammonia removal. However, the presence of 1, 10 and 50 mg/L of CuO NPs decreased COD removal from 78.7% to 77%, 52.1% and 39.2%, respectively (P < 0.05). The corresponding effluent ammonium (NH 4 -N) concentration increased from 14.9 mg/L to 18, 25.1 and 30.8 mg/L, respectively. Under equal Cu concentration, copper ions were more toxic towards microorganisms compared to CuO NPs. CuO NPs were removed effectively (72-93.2%) from wastewater due to a greater biosorption capacity of CuO NPs onto activated sludge, compared to the copper ions (55.1-83.4%). The SEM images clearly showed the accumulation and adsorption of CuO NPs onto activated sludge. The decrease in Live/dead ratio after 5 h of exposure of CuO NPs and Cu 2+ indicated the loss of cell viability in sludge flocs.

The prevalence of low serum zinc and copper levels and dietary habits associated with serum zinc and copper in 12- to 36-month-old children from low-income families at risk for iron deficiency.

PubMed

Schneider, Julie M; Fujii, Mary L; Lamp, Catherine L; Lönnerdal, Bo; Zidenberg-Cherr, Sheri

2007-11-01

Iron and zinc share common food sources, and children at risk of iron deficiency may also develop zinc deficiency. We determined the prevalence of zinc and copper deficiency and examined factors associated with serum zinc and copper in young children from low-income families at risk of iron deficiency. A cross-sectional study design was used to assess serum zinc and copper, along with an interview-assisted survey to assess factors associated with serum zinc and copper in a convenience sample. Participants were 435 children aged 12 to 36 months recruited from select clinics of the Special Supplemental Nutrition Program for Women, Infants, and Children in Contra Costa and Tulare Counties, California. Frequencies were used to report prevalence. Multiple linear regressions were conducted to examine factors associated with serum zinc and copper, controlling for age, sex, and ethnicity. The prevalence of low serum zinc level (<70 microg/dL [<10.7 micromol/L]) was 42.8%, and low serum copper level (<90 microg/dL [<14.2 micromol/L]) was <1%. Mean+/-standard deviation of serum copper was 150+/-22 microg/dL (23.6+/-3.5 micromol/L) and 140+/-24 microg/dL (22.1+/-3.8 micromol/L) for anemic and non-anemic children, respectively (t test, P=0.026). In multiple linear regression consumption of sweetened beverages was negatively associated with serum zinc level, and consumption of >15 g/day meat was positively associated with serum zinc level, whereas current consumption of breast milk and >15 g/day beans were positively associated with serum copper level. The prevalence of low serum zinc concentration in the sample was high, and warrants further investigation amongst vulnerable populations.

Integration of chemical and toxicological tools to assess the bioavailability of copper derived from different copper-based fungicides in soil.

PubMed

Wang, Quan-Ying; Sun, Jing-Yue; Xu, Xing-Jian; Yu, Hong-Wen

2018-06-20

Because the extensive use of Cu-based fungicides, the accumulation of Cu in agricultural soil has been widely reported. However, little information is known about the bioavailability of Cu deriving from different fungicides in soil. This paper investigated both the distribution behaviors of Cu from two commonly used fungicides (Bordeaux mixture and copper oxychloride) during the aging process and the toxicological effects of Cu on earthworms. Copper nitrate was selected as a comparison during the aging process. The distribution process of exogenous Cu into different soil fractions involved an initial rapid retention (the first 8 weeks) and a following slow continuous retention. Moreover, Cu mainly moved from exchangeable and carbonate fractions to Fe-Mn oxides-combined fraction during the aging process. The Elovich model fit well with the available Cu aging process, and the transformation rate was in the order of Cu(NO 3 ) 2 > Bordeaux mixture > copper oxychloride. On the other hand, the biological responses of earthworms showed that catalase activities and malondialdehyde contents of the copper oxychloride treated earthworms were significantly higher than those of Bordeaux mixture treated earthworms. Also, body Cu loads of earthworms from different Cu compounds spiked soils were in the following order: copper oxychloride > Bordeaux mixture. Thus, the bioavailability of Cu from copper oxychloride in soil was significantly higher than that of Bordeaux mixture, and different Cu compounds should be taken into consideration when studying the bioavailability of Cu-based fungicides in the soil. Copyright © 2018 Elsevier Inc. All rights reserved.

In Vitro Bioavailability of Calcium, Magnesium, Iron, Zinc, and Copper from Gluten-Free Breads Supplemented with Natural Additives.

PubMed

Regula, J; Cerba, A; Suliburska, J; Tinkov, A A

2018-03-01

The aim of this study was to measure the content of calcium, magnesium, iron, zinc, and copper and determine the bioavailability of these ingredients in gluten-free breads fortified with milk and selected seeds. Due to the increasing prevalence of celiac disease and mineral deficiencies, it has become necessary to produce food with higher nutritional values which maintains the appropriate product characteristics. This study was designed for gluten-free breads fortified with milk and seeds such as flax, poppy, sunflower seeds, pumpkin seeds or nuts, and flour with amaranth. Subsequently, digestion was performed in vitro and the potential bioavailability of the minerals was measured. In the case of calcium, magnesium, iron, and copper, higher bioavailability was observed in rice bread, and, in the case of copper and zinc, in buckwheat bread. This demonstrated a clear increase in bioavailability of all the minerals when the bread were enriched. However, satisfactory results are obtained only for the individual micronutrients.

Effects of Cu and Ag as ternary and quaternary additions on some physical properties of SnSb7 bearing alloy

NASA Astrophysics Data System (ADS)

El-Bediwi, A. B.

2004-02-01

The structure, electrical resistivity, and elastic modulus of SnSb7 and SnSb7X (X = Cu , Ag, or Cu and Ag) rapidly solidified alloys have been investigated using X-ray diffractometer, double bridge, and dynamic resonance techniques. Copper and silver additions to SnSb result in the formation of a eutectic matrix containing embedded crystals (intermetallic phases) of SnCu, SnAg, and SnSb. The hard crystals SnCu, SnAg, and SnSb increase the overall hardness and wear resistance of SnSb bearing alloys. Addition of copper and silver improves internal friction, electrical conductivity, and elastic modulus values of SnSb rapidly solidified bearing alloys. The internal friction, elastic modulus, and electrical resistivity values are relatively sensitive to the composition of the intermediate phases in the matrix. The SbSb(7)Cu(2)g(2) has better properties (lowest internal friction, cost, adequate elastic modulus, and electrical resistivity) for bearing alloys as compared to cast iron and bronzes.

Development of a selective and sensitive flotation method for determination of trace amounts of cobalt, nickel, copper and iron in environmental samples.

PubMed

Karimi, H; Ghaedi, M; Shokrollahi, A; Rajabi, H R; Soylak, M; Karami, B

2008-02-28

A simple, selective and rapid flotation method for the separation-preconcentration of trace amounts of cobalt, nickel, iron and copper ions using phenyl 2-pyridyl ketone oxime (PPKO) has been developed prior to their flame atomic absorption spectrometric determinations. The influence of pH, amount of PPKO as collector, type and amount of eluting agent, type and amount of surfactant as floating agent and ionic strength was evaluated on the recoveries of analytes. The influences of the concomitant ions on the recoveries of the analyte ions were also examined. The enrichment factor was 93. The detection limits based on 3 sigma for Cu, Ni, Co and Fe were 0.7, 0.7, 0.8, and 0.7 ng mL(-1), respectively. The method has been successfully applied for determination of trace amounts of ions in various real samples.

Zinc Pyrithione Inhibits Yeast Growth through Copper Influx and Inactivation of Iron-Sulfur Proteins▿†

PubMed Central

Reeder, Nancy L.; Kaplan, Jerry; Xu, Jun; Youngquist, R. Scott; Wallace, Jared; Hu, Ping; Juhlin, Kenton D.; Schwartz, James R.; Grant, Raymond A.; Fieno, Angela; Nemeth, Suzanne; Reichling, Tim; Tiesman, Jay P.; Mills, Tim; Steinke, Mark; Wang, Shuo L.; Saunders, Charles W.

2011-01-01

Zinc pyrithione (ZPT) is an antimicrobial material with widespread use in antidandruff shampoos and antifouling paints. Despite decades of commercial use, there is little understanding of its antimicrobial mechanism of action. We used a combination of genome-wide approaches (yeast deletion mutants and microarrays) and traditional methods (gene constructs and atomic emission) to characterize the activity of ZPT against a model yeast, Saccharomyces cerevisiae. ZPT acts through an increase in cellular copper levels that leads to loss of activity of iron-sulfur cluster-containing proteins. ZPT was also found to mediate growth inhibition through an increase in copper in the scalp fungus Malassezia globosa. A model is presented in which pyrithione acts as a copper ionophore, enabling copper to enter cells and distribute across intracellular membranes. This is the first report of a metal-ligand complex that inhibits fungal growth by increasing the cellular level of a different metal. PMID:21947398

Selenium, copper, zinc, iron levels and mortality in patients with sepsis and systemic inflammatory response syndrome in Western Black Sea Region, Turkey.

PubMed

Ayoglu, Hilal; Sezer, Ustun; Akin, Mehmet; Okyay, Dilek; Ayoglu, Ferruh; Can, Murat; Kucukosman, Gamze; Piskin, Ozcan; Aydin, Bengu; Cimencan, Murat; Gur, Abdullah; Turan, Isil

2016-04-01

To evaluate the changing levels of selenium, copper, zinc and iron in patients with sepsis and systemic inflammatory response syndrome and their influence on mortality. The prospective study was conducted at a tertiary care university hospital in Zonguldak city in the western Black Sea region of Turkey from January 2012 to December 2013, and comprised patients with sepsis and systemic inflammatory response syndrome. Blood samples were taken on 1st, 3rd, 5th and 7th days to measure serum selenium, copper, zinc and iron levels. Patients' demographic data, presence of additional diseases and mortality were recorded. Of the 57 patients, 28(49.1%) were female and 29(50.9%) were male, with an overall mean age of 60.3±19.4 years, mean height of 166.1±11.4cm, mean weight of 76.5±17.5kg. Copper and zinc levels were in the normal range, while selenium and iron levels were lower than the limit values at all measuring periods. There was no significant difference between first and other days in accordance with element levels (p>0.05). Baseline copper levels in patients with malignancy were lower than patients without malignancy (p< 0.05). In hypertensive patients, baseline copper levels were higher and 7th day levels were lower than non-hypertensive (p< 0.05). Baseline selenium levels of those who died were lower than the other patients (p< 0.05). Selenium and iron levels were decreased in patients with sepsis-systemic inflammatory response syndrome and copper levels were lower in patients with malignancy, hypertension and chronic obstructive pulmonary disease (p< 0.05). There was no change in zinc levels of the patients. Reduced basal selenium levels of patients with sepsis and systemic inflammatory response syndrome were associated with mortality.

Aspartate aminotransferase is potently inhibited by copper complexes: Exploring copper complex-binding proteome.

PubMed

Jia, Yuqi; Lu, Liping; Yuan, Caixia; Feng, Sisi; Zhu, Miaoli

2017-05-01

Recent researches indicated that a copper complex-binding proteome that potently interacted with copper complexes and then influenced cellular metabolism might exist in organism. In order to explore the copper complex-binding proteome, a copper chelating ion-immobilized affinity chromatography (Cu-IMAC) column and mass spectrometry were used to separate and identify putative Cu-binding proteins in primary rat hepatocytes. A total of 97 putative Cu-binding proteins were isolated and identified. Five higher abundance proteins, aspartate aminotransferase (AST), malate dehydrogenase (MDH), catalase (CAT), calreticulin (CRT) and albumin (Alb) were further purified using a SP-, and (or) Q-Sepharose Fast Flow column. The interaction between the purified proteins and selected 11 copper complexes and CuCl 2 was investigated. The enzymes inhibition tests demonstrated that AST was potently inhibited by copper complexes while MDH and CAT were weakly inhibited. Schiff-based copper complexes 6 and 7 potently inhibited AST with the IC 50 value of 3.6 and 7.2μM, respectively and exhibited better selectivity over MDH and CAT. Fluorescence titration results showed the two complexes tightly bound to AST with binding constant of 3.89×10 6 and 3.73×10 6 M -1 , respectively and a stoichiometry ratio of 1:1. Copper complex 6 was able to enter into HepG2 cells and further inhibit intracellular AST activity. Copyright © 2017 Elsevier Inc. All rights reserved.

Copper tolerance and virulence in bacteria

PubMed Central

Ladomersky, Erik; Petris, Michael J.

2015-01-01

Copper (Cu) is an essential trace element for all aerobic organisms. It functions as a cofactor in enzymes that catalyze a wide variety of redox reactions due to its ability to cycle between two oxidation states, Cu(I) and Cu(II). This same redox property of copper has the potential to cause toxicity if copper homeostasis is not maintained. Studies suggest that the toxic properties of copper are harnessed by the innate immune system of the host to kill bacteria. To counter such defenses, bacteria rely on copper tolerance genes for virulence within the host. These discoveries suggest bacterial copper intoxication is a component of host nutritional immunity, thus expanding our knowledge of the roles of copper in biology. This review summarizes our current understanding of copper tolerance in bacteria, and the extent to which these pathways contribute to bacterial virulence within the host. PMID:25652326

Copper solubility in a basaltic melt and sulfide liquid/silicate melt partition coefficients of Cu and Fe

NASA Astrophysics Data System (ADS)

Ripley, Edward M.; Brophy, James G.; Li, Chusi

2002-09-01

The solubility of copper in a sulfur-saturated basaltic melt has been determined at 1245°C as a function of fO 2 and fS 2. Copper solubilities at log fO 2 values between -8 and -11 fall into two distinct populations as a function of fS 2. At log fS 2 values < -1.65, sulfide liquid that coexists with the basaltic glass quenches to sulfur-poor bornite solid solution. At log fS 2 values in excess of -1.65, the sulfide liquid quenches to a complex intergrowth of sulfur-rich bornite and intermediate solid solution. Copper solubilities in the low-fS 2 population range from 594 to 1550 ppm, whereas those in the high-fS 2 population range from 80 to 768 ppm. Sulfide liquid/silicate liquid partition coefficients (D) for Cu and Fe range from 480 to 1303 and 0.7 to 13.6, respectively. Metal-sulfur complexing in the silicate liquid is shown to be insignificant relative to metal-oxide complexing for Fe but permissible for Cu at high fS 2 values. On log D Fe (sulfide-silicate) and log D Cu (sulfide-silicate) vs. 1/2 (log fS 2 - log fO 2) diagrams, both fS 2 populations show distinct but parallel trends. The observation of two D values for any fS 2/fO 2 ratio indicates nonideal mixing of species involved in the exchange reaction. The two distinct trends observed for both Cu and Fe are thought to be due to variations in activity coefficient ratios (e.g., γ FeO/γ FeS and γ CuO 0.5/γ CuS 0.5). Results of the experiments suggest that accurate assessments of fS 2/fO 2 ratios are required for the successful numerical modeling of processes such as the partial melting of sulfide-bearing mantle and the crystallization of sulfide-bearing magmas, as well as the interpretation of sulfide mineralogical zoning. In addition, the experiments provide evidence for oxide or oxy-sulfide complexing for Cu in silicate magmas and suggest that the introduction of externally derived sulfur to mafic magma may be an important process for the formation of Cu-rich disseminated magmatic sulfide ore

Correlations in distribution and concentration of calcium, copper and iron with zinc in isolated extracellular deposits associated with age-related macular degeneration

USGS Publications Warehouse

Flinn, Jane M; Kakalec, Peter; Tappero, Ryan; Jones, Blair F.; Lengyel, Imre

2014-01-01

Zinc (Zn) is abundantly enriched in sub-retinal pigment epithelial (RPE) deposits, the hallmarks of age-related macular degeneration (AMD), and is thought to play a role in the formation of these deposits. However, it is not known whether Zn is the only metal relevant for sub-RPE deposit formation. Because of their involvement in the pathogenesis of AMD, we determined the concentration and distribution of calcium (Ca), iron (Fe) and copper (Cu) and compared these with Zn in isolated and sectioned macular (MSD), equatorial (PHD) and far peripheral (FPD) sub-RPE deposits from an 86 year old donor eye with post mortem diagnosis of early AMD. The sections were mounted on Zn free microscopy slides and analyzed by microprobe synchrotron X-ray fluorescence (μSXRF). Metal concentrations were determined using spiked sectioned sheep brain matrix standards, prepared the same way as the samples. The heterogeneity of metal distributions was examined using pixel by pixel comparison. The orders of metal concentrations were Ca ⋙ Zn > Fe in all three types of deposits but Cu levels were not distinguishable from background values. Zinc and Ca were consistently present in all deposits but reached highest concentration in MSD. Iron was present in some but not all deposits and was especially enriched in FPD. Correlation analysis indicated considerable variation in metal distribution within and between sub-RPE deposits. The results suggest that Zn and Ca are the most likely contributors to deposit formation especially in MSD, the characteristic risk factor for the development of AMD in the human eye.

Column bioleaching copper and its kinetics of waste printed circuit boards (WPCBs) by Acidithiobacillus ferrooxidans.

PubMed

Chen, Shu; Yang, Yuankun; Liu, Congqiang; Dong, Faqin; Liu, Bijun

2015-12-01

Application of bioleaching process for metal recovery from electronic waste has received an increasing attention in recent years. In this work, a column bioleaching of copper from waste printed circuit boards (WPCBs) by Acidithiobacillus ferrooxidans has been investigated. After column bioleaching for 28d, the copper recovery reached at 94.8% from the starting materials contained 24.8% copper. Additionally, the concentration of Fe(3+) concentration varied significantly during bioleaching, which inevitably will influence the Cu oxidation, thus bioleaching process. Thus the variation in Fe(3+) concentration should be taken into consideration in the conventional kinetic models of bioleaching process. Experimental results show that the rate of copper dissolution is controlled by external diffusion rather than internal one because of the iron hydrolysis and formation of jarosite precipitates at the surface of the material. The kinetics of column bioleaching WPCBs remains unchanged because the size and morphology of precipitates are unaffected by maintaining the pH of solution at 2.25 level. In bioleaching process, the formation of jarosite precipitate can be prevented by adding dilute sulfuric acid and maintaining an acidic condition of the leaching medium. In such way, the Fe(2)(+)-Fe(3+) cycle process can kept going and create a favorable condition for Cu bioleaching. Our experimental results show that column Cu bioleaching from WPCBs by A. ferrooxidans is promising. Copyright © 2015 Elsevier Ltd. All rights reserved.

Calculation of Distribution Coefficients of Cobalt and Copper in Matte and Slag Phases in Reduction-Vulcanization Process of Copper Converter Slag

NASA Astrophysics Data System (ADS)

Du, Ke; Li, Hongxu; Zhang, Mingming

2017-11-01

Copper and cobalt are two of the most valuable metals that can be recovered from copper converter slag. In the reduction-vulcanization process, copper is reduced before cobalt, while FeS vulcanizes Cu2O into Cu2S and forms the matte phase. The matte phase can dissolve the reduced metals as solvent. In this study, the distribution coefficient of cobalt between metallic cobalt in matte and CoO in slag, namely L Co, was calculated to be 5000-8500 at the reaction temperature of 1600-1700 K, while the distribution coefficient between CoS and CoO, namely L_{Co}^{{^' } }}, was calculated to be between 6 and 8. The distribution coefficient of copper between metallic copper in matte and Cu2O in slag, namely L Cu, was calculated to be in the range of 7500-8500, while the coefficient between Cu2S and Cu2O, namely L_{Cu}^{{^' } }}, was calculated to be in the range of 60,000-75,000.

Effect of Tamarindus indica leaf powder on plasma concentrations of copper, zinc, and iron in fluorotic cows.

PubMed

Samal, Pinaki; Patra, R C; Gupta, A R; Mishra, S K; Jena, D; Satapathy, D

2016-10-01

The main objective of the study was to determine the deleterious effect of fluoride on plasma trace minerals of fluorotic cattle and to evaluate the effect of Tamarindus indica leaf powder toward correction of the same. A total of 30 cattle exhibiting chronic sign of fluorosis and 10 healthy cattle from nonfluorotic area were incorporated in this study. Fluorotic cattle were divided into three equal groups consisting of 10 cattle each. Group I from fluoride free area served as healthy control. The Group II received no treatment and served as disease control. Groups III and IV were supplemented with tamarind leaf powder at 15 g and 30 g/day with feed for 60 days. Plasma mineral status was evaluated after 60 days of treatment with double beam atomic absorption spectrophotometer. Statistical analysis of data revealed a significant (p<0.05) decrease in mean plasma copper (Cu) (0.344±0.007 ppm), zinc (Zn) (0.692±0.06 ppm), and iron (Fe) concentration (1.100±0.01 ppm) in fluorotic cattle in comparison to healthy cattle (0.58±0.010, 2.342±0.04, 1.406±0.04 ppm, respectively). Significant (p<0.05) increase in Cu, Zn, and Fe was recorded after supplementation of tamarind leaf powder to the fluorotic cattle. It was concluded that fluorotic cattle might be supplemented with T. indica leaf powder with feed for the correction of the decreased level of certain plasma minerals.

Obtention of low oxidation states of copper from Cu 2+-Al 3+ layered double hydroxides containing organic sulfonates in the interlayer

NASA Astrophysics Data System (ADS)

Trujillano, Raquel; Holgado, María Jesús; Rives, Vicente

2009-03-01

A series of hydrotalcite-type compounds containing Cu(II) and Al(III) in the layers, and carbonate or different alkylsulfonates in the interlayer, have been prepared and studied. Calcination of these solids gives rise to formation of metallic copper and Cu 2+ and Cu + oxides or sulfates, depending on the calcination temperature and on the precise nature of the interlayer alkylsulfonate.

Copper oxide nanoparticles and bulk copper oxide, combined with indole-3-acetic acid, alter aluminum, boron, and iron in Pisum sativum seeds.

PubMed

Ochoa, Loren; Zuverza-Mena, Nubia; Medina-Velo, Illya A; Flores-Margez, Juan Pedro; Peralta-Videa, José R; Gardea-Torresdey, Jorge L

2018-09-01

The interaction of CuO nanoparticles (nCuO), a potential nanopesticide, with the growth hormone indole-3-acetic acid (IAA) is not well understood. This study aimed to evaluate the nutritional components in seeds of green pea (Pisum sativum) cultivated in soil amended with nCuO at 50 or 100mgkg -1 , with/without IAA at 10 or 100μM. Similar treatments including bulk CuO (bCuO) and CuCl 2 were set as controls. Bulk CuO at 50mgkg -1 reduced seed yield (52%), compared with control. Bulk CuO at 50mgkg -1 and nCuO at 100mgkg -1 , plus IAA at 100μM, increased iron in seeds (41 and 42%, respectively), while nCuO at 50mgkg -1 , plus IAA at 100μM reduced boron (80%, respect to control and 63%, respect to IAA at 100μM). IAA, at 10μM increased seed protein (33%), compared with control (p≤0.05). At both concentrations IAA increased sugar in seeds (20%). Overall, nCuO, plus IAA at 10μM, does not affect the production or nutritional quality of green pea seeds. Copyright © 2018 Elsevier B.V. All rights reserved.

The BiCu{sub 1−x}OS oxysulfide: Copper deficiency and electronic properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berthebaud, D.; Guilmeau, E.; Lebedev, O.I.

2016-05-15

An oxysulfide series of nominal compositions BiCu{sub 1−x}OS with x<0.20 has been prepared and its structural properties characterized by combining powder X-ray diffraction and transmission electron microscopy techniques. It is found that this oxysulfide, crystallizing in the P4/nmm space group, tends to adopt a constant amount of copper vacancy corresponding to x=0.05 in the BiCu{sub 1−x}OS formula. The presence of Cu vacancies is confirmed by HAADF-STEM analysis showing, in the Cu atomic columns, alternating peaks of different intensities in some very localized regions. For larger Cu deficiencies (x>0.05 in the nominal composition), other types of structural nanodefects are evidenced suchmore » as bismuth oxysulfides of the “BiOS” ternary system which might explain the report of superconductivity for the BiCu{sub 1−x}OS oxysulfide. Local epitaxial growth of the BiCuOS oxysulfide on top of CuO is also observed. In marked contrast to the BiCu{sub 1−x}OSe oxyselenide, these results give an explanation to the limited impact of Cu deficiency on the Seebeck coefficient in BiCu{sub 1−x}OS compounds. - Graphical abstract: High resolution TEM image showing a Bi(Cu)OS/Bi{sub 2}O{sub 2}S interface and corresponding dislocation region. The Bi(Cu)OS structure adopts a rather constant Cu content (near 0.95); starting from BiCuOS leads to the formation of defects such as the Bi{sub 2}O{sub 2}S oxysulfide.« less

Copper stabilization via spinel formation during the sintering of simulated copper-laden sludge with aluminum-rich ceramic precursors.

PubMed

Tang, Yuanyuan; Chui, Stephen Sin-Yin; Shih, Kaimin; Zhang, Lingru

2011-04-15

The feasibility of incorporating copper-laden sludge into low-cost ceramic products, such as construction ceramics, was investigated by sintering simulated copper-laden sludge with four aluminum-rich ceramic precursors. The results indicated that all of these precursors (γ-Al(2)O(3), corundum, kaolinite, mullite) could crystallochemically stabilize the hazardous copper in the more durable copper aluminate spinel (CuAl(2)O(4)) structure. To simulate the process of copper transformation into a spinel structure, CuO was mixed with the four aluminum-rich precursors, and fired at 650-1150 °C for 3 h. The products were examined using powder X-ray diffraction (XRD) and scanning electron microscopic techniques. The efficiency of copper transformation among crystalline phases was quantitatively determined through Rietveld refinement analysis of the XRD data. The sintering experiment revealed that the optimal sintering temperature for CuAl(2)O(4) formation was around 1000 °C and that the efficiency of copper incorporation into the crystalline CuAl(2)O(4) structure after 3 h of sintering ranged from 40 to 95%, depending on the type of aluminum precursor used. Prolonged leaching tests were carried out by using acetic acid with an initial pH value of 2.9 to leach CuO and CuAl(2)O(4) samples for 22 d. The sample leachability analysis revealed that the CuAl(2)O(4) spinel structure was more superior to stabilize copper, and suggested a promising and reliable technique for incorporating copper-laden sludge or its incineration ash into usable ceramic products. Such results also demonstrated the potential of a waste-to-resource strategy by using waste materials as part of the raw materials with the attainable temperature range used in the production of ceramics.

Cu-Doped ZnO Thin Films Deposited by a Sol-Gel Process Using Two Copper Precursors: Gas-Sensing Performance in a Propane Atmosphere

PubMed Central

Gómez-Pozos, Heberto; Arredondo, Emma Julia Luna; Maldonado Álvarez, Arturo; Biswal, Rajesh; Kudriavtsev, Yuriy; Pérez, Jaime Vega; Casallas-Moreno, Yenny Lucero; Olvera Amador, María de la Luz

2016-01-01

A study on the propane gas-sensing properties of Cu-doped ZnO thin films is presented in this work. The films were deposited on glass substrates by sol-gel and dip coating methods, using zinc acetate as a zinc precursor, copper acetate and copper chloride as precursors for doping. For higher sensitivity values, two film thickness values are controlled by the six and eight dippings, whereas for doping, three dippings were used, irrespective of the Cu precursor. The film structure was analyzed by X-ray diffractometry, and the analysis of the surface morphology and film composition was made through scanning electron microscopy (SEM) and secondary ion mass spectroscopy (SIMS), respectively. The sensing properties of Cu-doped ZnO thin films were then characterized in a propane atmosphere, C3H8, at different concentration levels and different operation temperatures of 100, 200 and 300 °C. Cu-doped ZnO films doped with copper chloride presented the highest sensitivity of approximately 6 × 104, confirming a strong dependence on the dopant precursor type. The results obtained in this work show that the use of Cu as a dopant in ZnO films processed by sol-gel produces excellent catalysts for sensing C3H8 gas. PMID:28787885

Cu-Doped ZnO Thin Films Deposited by a Sol-Gel Process Using Two Copper Precursors: Gas-Sensing Performance in a Propane Atmosphere.

PubMed

Gómez-Pozos, Heberto; Arredondo, Emma Julia Luna; Maldonado Álvarez, Arturo; Biswal, Rajesh; Kudriavtsev, Yuriy; Pérez, Jaime Vega; Casallas-Moreno, Yenny Lucero; Olvera Amador, María de la Luz

2016-01-29

A study on the propane gas-sensing properties of Cu-doped ZnO thin films is presented in this work. The films were deposited on glass substrates by sol-gel and dip coating methods, using zinc acetate as a zinc precursor, copper acetate and copper chloride as precursors for doping. For higher sensitivity values, two film thickness values are controlled by the six and eight dippings, whereas for doping, three dippings were used, irrespective of the Cu precursor. The film structure was analyzed by X-ray diffractometry, and the analysis of the surface morphology and film composition was made through scanning electron microscopy (SEM) and secondary ion mass spectroscopy (SIMS), respectively. The sensing properties of Cu-doped ZnO thin films were then characterized in a propane atmosphere, C₃H₈, at different concentration levels and different operation temperatures of 100, 200 and 300 °C. Cu-doped ZnO films doped with copper chloride presented the highest sensitivity of approximately 6 × 10⁴, confirming a strong dependence on the dopant precursor type. The results obtained in this work show that the use of Cu as a dopant in ZnO films processed by sol-gel produces excellent catalysts for sensing C₃H₈ gas.

Synthesis of copper oxide nanowires and nanoporous copper via environmentally friendly transformation of bulk copper-calcium alloys.

PubMed

Zhang, X; Turcheniuk, K; Zusmann, B; Benson, J; Nelson, S; Luo, S; Magasinski, A; Yushin, G

2018-05-24

In this work, we report a novel, one-step, inexpensive and environmentally friendly synthesis of Cu nanostructures by means of chemical de-alloying of bulk Cu-Ca alloys in aqueous solutions. By controlling the synthesis conditions, we tune the morphology of the nanostructured Cu from nanoporous Cu to copper oxide nanowires.

Construction of Hierarchical CuO/Cu2O@NiCo2S4 Nanowire Arrays on Copper Foam for High Performance Supercapacitor Electrodes

PubMed Central

Zhou, Luoxiao; He, Ying; Jia, Congpu; Pavlinek, Vladimir; Saha, Petr; Cheng, Qilin

2017-01-01

Hierarchical copper oxide @ ternary nickel cobalt sulfide (CuO/Cu2O@NiCo2S4) core-shell nanowire arrays on Cu foam have been successfully constructed by a facile two-step strategy. Vertically aligned CuO/Cu2O nanowire arrays are firstly grown on Cu foam by one-step thermal oxidation of Cu foam, followed by electrodeposition of NiCo2S4 nanosheets on the surface of CuO/Cu2O nanowires to form the CuO/Cu2O@NiCo2S4 core-shell nanostructures. Structural and morphological characterizations indicate that the average thickness of the NiCo2S4 nanosheets is ~20 nm and the diameter of CuO/Cu2O core is ~50 nm. Electrochemical properties of the hierarchical composites as integrated binder-free electrodes for supercapacitor were evaluated by various electrochemical methods. The hierarchical composite electrodes could achieve ultrahigh specific capacitance of 3.186 F cm−2 at 10 mA cm−2, good rate capability (82.06% capacitance retention at the current density from 2 to 50 mA cm−2) and excellent cycling stability, with capacitance retention of 96.73% after 2000 cycles at 10 mA cm−2. These results demonstrate the significance of optimized design and fabrication of electrode materials with more sufficient electrolyte-electrode interface, robust structural integrity and fast ion/electron transfer. PMID:28914819

Evaluation of metal mobility from copper mine tailings in northern Chile.

PubMed

Lam, Elizabeth J; Gálvez, M E; Cánovas, M; Montofré, I L; Rivero, D; Faz, A

2016-06-01

This work shows the results obtained on a copper mine tailing in the Antofagasta Region, Chile. The tailing was classified as saline-sodic with high concentrations of metals, especially Cu and Fe, with pH 8.4. Our objectives were to (1) compare the physicochemical properties of the tailing with surrounding soils of the mine under study, and (2) evaluate the effect of two amendments (CaCO3 and compost) and their mixtures on Cu(2+), Mn, Fe, Zn, Mg(2+), and K(+) and Ca(2+), SO4 (2-), NO3 (-), and PO4 (3-) leaching. The data obtained were submitted to variance and covariance analysis. The results from the comparison between both substrates showed that in general, the tailing presented greater content of metals. Regarding tailing leaching, pH, electrical conductivity (EC), and concentration of the elements of interest were measured. The statistical analysis showed that Cu(2+) leaching and immobilization of Fe occurred to the greatest extent with compost. The EC decreased throughout the experiment with irrigation and increased upon treatment with compost. The major interactions found among the chemical parameters were (1) tailings without treatment, Cu(2+)/Fe and NO3 (-)/SO4 (2-); (2) tailings treated with CaCO3, Cu(2+)/K(+); (3) tailings treated with compost, NO3 (-)/SO4 (-2) and EC/Cu(2+); and (4) tailings treated with both amendments, EC/Fe and Cu(2+)/Fe. The ANOVA showed that the number of irrigations and the amendments statistically significantly affected the copper mobility and the organic amendment significantly influenced the iron mobility.

Mechanical properties and microstructure of copper alloys and copper alloy-stainless steel laminates for fusion reactor high heat flux applications

NASA Astrophysics Data System (ADS)

Leedy, Kevin Daniel

A select group of copper alloys and bonded copper alloy-stainless steel panels are under consideration for heat sink applications in first wall and divertor structures of a planned thermonuclear fusion reactor. Because these materials must retain high strengths and withstand high heat fluxes, their material properties and microstructures must be well understood. Candidate copper alloys include precipitate strengthened CuNiBe and CuCrZr and dispersion strengthened Cu-Alsb2Osb3 (CuAl25). In this study, uniaxial mechanical fatigue tests were conducted on bulk copper alloy materials at temperatures up to 500sp°C in air and vacuum environments. Based on standardized mechanical properties measurement techniques, a series of tests were also implemented to characterize copper alloy-316L stainless steel joints produced by hot isostatic pressing or by explosive bonding. The correlation between mechanical properties and the microstructure of fatigued copper alloys and the interface of copper alloy-stainless steel laminates was examined. Commercial grades of these alloys were used to maintain a degree of standardization in the materials testing. The commercial alloys used were OMG Americas Glidcop CuAl25 and CuAl15; Brush Wellman Hycon 3HP and Trefimetaux CuNiBe; and Kabelmetal Elbrodur and Trefimetaux CuCrZr. CuAl25 and CuNiBe alloys possessed the best combination of fatigue resistance and microstructural stability. The CuAl25 alloy showed only minimal microstructural changes following fatigue while the CuNiBe alloy consistently exhibited the highest fatigue strength. Transmission electron microscopy observations revealed that small matrix grain sizes and high densities of submicron strengthening phases promoted homogeneous slip deformation in the copper alloys. Thus, highly organized fatigue dislocation structure formation, as commonly found in oxygen-free high conductivity Cu, was inhibited. A solid plate of CuAl25 alloy hot isostatically pressed to a 316L stainless steel

Ionic Diffusion in Cu6PS5Br Studied by 63Cu NMR

NASA Astrophysics Data System (ADS)

Ohki, H.; Harazono, K.; Erata, T.; Tasaki, A.; Ikeda, R.

1993-10-01

Applying 63Cu NMR technique, we observed exchange between the nonequivalent copper sites in crystalline Cu6PS5Br, known as a member of the mineral "argyrodite". Below 200 K, where the motion of the copper (I) ion is slow, we could distinguish several nonequivalent copper sites. On increasing the temperature, the chemical exchange between the nonequivalent cation sites was seen on the 63Cu NMR spectra. We could determine the activation energy for this motion to be 35 kJ mol-1 , in good agreement with the published ionic conductivity.