Copper-tantalum alloy

DOEpatents

Schmidt, Frederick A.; Verhoeven, John D.; Gibson, Edwin D.

1986-07-15

A tantalum-copper alloy can be made by preparing a consumable electrode consisting of an elongated copper billet containing at least two spaced apart tantalum rods extending longitudinally the length of the billet. The electrode is placed in a dc arc furnace and melted under conditions which co-melt the copper and tantalum to form the alloy.

A cytosolic copper storage protein provides a second level of copper tolerance in Streptomyces lividans.

PubMed

Straw, Megan L; Chaplin, Amanda K; Hough, Michael A; Paps, Jordi; Bavro, Vassiliy N; Wilson, Michael T; Vijgenboom, Erik; Worrall, Jonathan A R

2018-01-24

Streptomyces lividans has a distinct dependence on the bioavailability of copper for its morphological development. A cytosolic copper resistance system is operative in S. lividans that serves to preclude deleterious copper levels. This system comprises of several CopZ-like copper chaperones and P 1 -type ATPases, predominantly under the transcriptional control of a metalloregulator from the copper sensitive operon repressor (CsoR) family. In the present study, we discover a new layer of cytosolic copper resistance in S. lividans that involves a protein belonging to the newly discovered family of copper storage proteins, which we have named Ccsp (cytosolic copper storage protein). From an evolutionary perspective, we find Ccsp homologues to be widespread in Bacteria and extend through into Archaea and Eukaryota. Under copper stress Ccsp is upregulated and consists of a homotetramer assembly capable of binding up to 80 cuprous ions (20 per protomer). X-ray crystallography reveals 18 cysteines, 3 histidines and 1 aspartate are involved in cuprous ion coordination. Loading of cuprous ions to Ccsp is a cooperative process with a Hill coefficient of 1.9 and a CopZ-like copper chaperone can transfer copper to Ccsp. A Δccsp mutant strain indicates that Ccsp is not required under initial copper stress in S. lividans, but as the CsoR/CopZ/ATPase efflux system becomes saturated, Ccsp facilitates a second level of copper tolerance.

rf breakdown measurements in electron beam driven 200 GHz copper and copper-silver accelerating structures

DOE PAGES

Dal Forno, Massimo; Dolgashev, Valery; Bowden, Gordon; ...

2016-11-30

This study explores the physics of vacuum rf breakdowns in subterahertz high-gradient traveling-wave accelerating structures. We present the experimental results of rf tests of 200 GHz metallic accelerating structures, made of copper and copper-silver. These experiments were carried out at the Facility for Advanced Accelerator Experimental Tests (FACET) at the SLAC National Accelerator Laboratory. The rf fields were excited by the FACET ultrarelativistic electron beam. The traveling-wave structure is an open geometry, 10 cm long, composed of two halves separated by a gap. The rf frequency of the fundamental accelerating mode depends on the gap size and can be changedmore » from 160 to 235 GHz. When the beam travels off axis, a deflecting field is induced in addition to the longitudinal field. We measure the deflecting forces by observing the displacement of the electron bunch and use this measurement to verify the expected accelerating gradient. Furthermore, we present the first quantitative measurement of rf breakdown rates in 200 GHz metallic accelerating structures. The breakdown rate of the copper structure is 10 –2 per pulse, with a peak surface electric field of 500 MV/m and a rf pulse length of 0.3 ns, which at a relatively large gap of 1.5 mm, or one wavelength, corresponds to an accelerating gradient of 56 MV/m. For the same breakdown rate, the copper-silver structure has a peak electric field of 320 MV/m at a pulse length of 0.5 ns. For a gap of 1.1 mm, or 0.74 wavelengths, this corresponds to an accelerating gradient of 50 MV/m.« less

Fabricating Copper Nanotubes by Electrodeposition

NASA Technical Reports Server (NTRS)

Yang, E. H.; Ramsey, Christopher; Bae, Youngsam; Choi, Daniel

2009-01-01

Copper tubes having diameters between about 100 and about 200 nm have been fabricated by electrodeposition of copper into the pores of alumina nanopore membranes. Copper nanotubes are under consideration as alternatives to copper nanorods and nanowires for applications involving thermal and/or electrical contacts, wherein the greater specific areas of nanotubes could afford lower effective thermal and/or electrical resistivities. Heretofore, copper nanorods and nanowires have been fabricated by a combination of electrodeposition and a conventional expensive lithographic process. The present electrodeposition-based process for fabricating copper nanotubes costs less and enables production of copper nanotubes at greater rate.

Multiphase separation of copper nanowires

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

Qian, Fang; Lan, Pui Ching; Olson, Tammy

Here, this communication reports a new method to purify copper nanowires with nearly 100% yield from undesired copper nanoparticle side-products formed during batch processes of copper nanowire synthesis. Also, this simple separation method can yield large quantities of long, uniform, high-purity copper nanowires to meet the requirements of nanoelectronics applications as well as provide an avenue for purifying copper nanowires in the industrial scale synthesis of copper nanowires, a key step for commercialization and application of nanowires.

Multiphase separation of copper nanowires

DOE PAGES

Qian, Fang; Lan, Pui Ching; Olson, Tammy; ...

2016-09-01

Here, this communication reports a new method to purify copper nanowires with nearly 100% yield from undesired copper nanoparticle side-products formed during batch processes of copper nanowire synthesis. Also, this simple separation method can yield large quantities of long, uniform, high-purity copper nanowires to meet the requirements of nanoelectronics applications as well as provide an avenue for purifying copper nanowires in the industrial scale synthesis of copper nanowires, a key step for commercialization and application of nanowires.

The gas-phase on-line formation of antimony oxide trihalides, SbOX 3 where X=F and Cl and their identifications by infrared spectroscopy

NASA Astrophysics Data System (ADS)

Allaf, Abdul W.; Ajji, Z.

2000-09-01

Antimony oxide trihalides, SbOX 3 molecules, where X=F or Cl have been produced, by means of an on-line process, using antimony trichloride, SbOCl 3 as starting material passed over heated silver oxide at 230°C. The antimony oxide trichloride SbOCl 3 formed is then reacted with sodium fluoride, NaF at 550°C to produce antimony oxide trifluoride, SbOF 3. The products have been characterized by the IR spectra of their vapors. Low resolution gas-phase Fourier transform infrared spectra show strong bands centered at 1272 and 1217 cm -1, assigned to ν 1(a 1), the OSb stretching fundamental of SbOF 3 and SbOCl 3, respectively. Both observed bands show typical PQR-type structure with a strong Q-head.

What's in the Walls: Copper, Fiber, or Coaxial Wiring?

ERIC Educational Resources Information Center

Weiss, Andrew M.

1995-01-01

Presents planning guidelines for wiring specifications for K-12 schools by reviewing advantages and disadvantages of using copper, fiber-optic, and coaxial wire. Addresses the future of network wiring and educational technology, and makes recommendations. A sidebar describes the physical appearance of different types of wire and a table compares…

The effect of natural and anthropogenic factors on sorption of copper in chernozem

NASA Astrophysics Data System (ADS)

Bauer, Tatiana; Minkina, Tatiana; Mandzhieva, Saglara; Pinskii, David; Linnik, Vitaly; Sushkova, Svetlana

2016-04-01

The aim of this work was to study the effect of the attendant anions and particle-size distribution on the adsorption of copper by ordinary chernozem. Solutions of HM nitrates, acetates, chlorides, and sulfates were used to study the effect of the chemical composition of added copper salts on the adsorption of copper by an ordinary chernozem. Samples of the soil sieved through a 1-mm sieve in the natural ionic form and soil fraction with different particle size (clay - the particle with size < 1μm and physical clay < 10 μm) were treated with solutions of the corresponding copper salts at a soil : solution ratio of 1:10. The concentrations of the initial copper solutions were 0.02, 0.05, 0.08, 0.1, 0.3, 0.5, and 1.0 mM/L. The range of Cu2+ concentrations in the studied system covers different geochemical situations corresponding to the actual levels of soil contamination with the metal under study. The suspensions were shaken for 1 h, left to stand for 24 h, and then filtered. The contents of the HM in the filtrates were determined by atomic absorption spectrometry (AAS). The contents of the adsorbed copper cations were calculated from the difference between the metal concentrations in the initial and equilibrium solutions. The isotherms of copper adsorption from the metal nitrate, chloride, and sulfate solutions have near linear shapes and, hence, can be satisfactorily described by a Henry or Freundlich equation: Cads = KH •Ceq.(1) Cads = KF •Ceqn,(2) where Cadsis the content of the adsorbed cations, mM/kg soil;Ceq is the concentration of copper in the equilibrium solution, mM/L; KH and KF denote the Henry and Freundlich adsorption coefficients, respectively, kg/L. The isotherm of Cu2+ adsorption by ordinary chernozem from acetate solutions is described by the Langmuir equation: Cads = C∞ÊLC / (1 + ÊLC), (3) where Cadsis the content of the adsorbed cations, mM/kg soil;C∞ is the maximum adsorption of the HM, mM/kg soil; ÊL is the affinity constant, L

Potential phytoextraction and phytostabilization of perennial peanut on copper-contaminated vineyard soils and copper mining waste.

PubMed

Andreazza, Robson; Bortolon, Leandro; Pieniz, Simone; Giacometti, Marcelo; Roehrs, Dione D; Lambais, Mácio R; Camargo, Flávio A O

2011-12-01

This study sought to evaluate the potential of perennial peanut (Arachis pintoi) for copper phytoremediation in vineyard soils (Inceptisol and Mollisol) contaminated with copper and copper mining waste. Our results showed high phytomass production of perennial peanut in both vineyard soils. Macronutrient uptakes were not negatively affected by perennial peanut cultivated in all contaminated soils. Plants cultivated in Mollisol showed high copper concentrations in the roots and shoots of 475 and 52 mg kg(-1), respectively. Perennial peanut plants showed low translocation factor values for Cu, although these plants showed high bioaccumulation factor (BCF) for both vineyard soils, Inceptisol and Mollisol, with BCF values of 3.83 and 3.24, respectively, being characterized as a copper hyperaccumulator plant in these soils. Copper phytoextraction from Inceptisol soil was the highest for both roots and entire plant biomass, with more than 800 mg kg(-1) of copper in whole plant. The highest potential copper phytoextraction by perennial peanut was in Inceptisol soil with copper removal of 2,500 g ha(-1). Also, perennial peanut showed high potential for copper phytoremoval in copper mining waste and Mollisol with 1,700 and 1,500 g of copper per hectare, respectively. In addition, perennial peanuts characterized high potential for phytoextraction and phytostabilization of copper in vineyard soils and copper mining waste.

Copper slag as a catalyst for mercury oxidation in coal combustion flue gas.

PubMed

Li, Hailong; Zhang, Weilin; Wang, Jun; Yang, Zequn; Li, Liqing; Shih, Kaimin

2018-04-01

Copper slag is a byproduct of the pyrometallurgical smelting of copper concentrate. It was used in this study to catalyze elemental mercury (Hg 0 ) oxidation in simulated coal combustion flue gas. The copper slag exhibited excellent catalytic performance in Hg 0 oxidation at temperatures between 200 °C and 300 °C. At the most optimal temperature of 250 °C, a Hg 0 oxidation efficiency of 93.8% was achieved under simulated coal combustion flue gas with both a high Hg 0 concentration and a high gas hourly space velocity of 128,000 h -1 . Hydrogen chloride (HCl) was the flue gas component responsible for Hg 0 oxidation over the copper slag. The transition metal oxides, including iron oxides and copper oxide in the copper slag, exhibited significant catalytic activities in the surface-mediated oxidation of Hg 0 in the presence of HCl. It is proposed that the Hg 0 oxidation over the copper slag followed the Langmuir-Hinshelwood mechanism whereby reactive chlorine species that originated from HCl reacted with the physically adsorbed Hg 0 to form oxidized mercury. This study demonstrated the possibility of reusing copper slag as a catalyst for Hg 0 oxidation and revealed the mechanisms involved in the process and the key factors in the performance. This knowledge has fundamental importance in simultaneously reducing industrial waste and controlling mercury emissions from coal-fired power plants. Copyright © 2017 Elsevier Ltd. All rights reserved.

The copper rush of the nineties.

PubMed

Solioz, Marc

2016-09-01

The nineties witnessed the discovery of the copper ATPases, enzymes which transport copper across the cytoplasmic membranes of bacteria and eukaryotes. In the same decade, several other key components of copper homeostasis have also been discovered, like copper chaperones and plasma membrane copper transporters. This has finally led to a molecular understanding of two inherited human diseases related to copper: Menkes disease, manifested by systemic copper deficiency, and Wilson disease, caused by defective secretion of excess copper. A historic perspective and untold stories of the events leading up to these discoveries are presented here.

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.

The copper metallome in eukaryotic cells.

PubMed

Vest, Katherine E; Hashemi, Hayaa F; Cobine, Paul A

2013-01-01

Copper is an element that is both essential and toxic. It is a required micronutrient for energy production in aerobic eukaryotes, from unicellular yeast to plants and mammals. Copper is also required for the acquisition and systemic distribution of the essential metal iron, and so copper deficiency results in iron deficiency. Copper enzymes have been identified that explain the wide variety of symptoms suffered by copper deficient subjects. The cloning of the genes encoding transport proteins responsible for copper-related Menkes and Wilson diseases inspired and coincided with the discovery of copper chaperones that stimulated the copper homeostasis field. Copper continues to be implicated in new array of proteins, notably those involved in a variety of neurodegenerative diseases. Here we will describe the cadre of important historical copper proteins and survey the major metallochaperones and transporters responsible for mobilization and sequestration of copper in yeast, mammals and plants.

Metallic copper corrosion rates, moisture content, and growth medium influence survival of copper-ion resistant bacteria

PubMed Central

Elguindi, Jutta; Moffitt, Stuart; Hasman, Henrik; Andrade, Cassandra; Raghavan, Srini; Rensing, Christopher

2013-01-01

The rapid killing of various bacteria in contact with metallic copper is thought to be influenced by influx of copper ions into the cells but the exact mechanism is not fully understood. This study showed that the kinetics of contact-killing of copper surfaces depended greatly on the amount of moisture present, copper content of alloys, type of medium used, and type of bacteria. We examined antibiotic- and copper-ion resistant strains of Escherichia coli and Enterococcus faecium isolated from pig farms following the use of copper sulfate as feed supplement. The results showed rapid killing of both copper-ion resistant E. coli and E. faecium strains when samples in rich medium were spread in a thin, moist layer on copper alloys with 85% or greater copper content. E. coli strains were rapidly killed under dry conditions while E. faecium strains were less affected. Electroplated copper surface corrosion rates were determined from electro-chemical polarization tests using the Stern-Geary method and revealed decreased corrosion rates with benzotriazole and thermal oxide coating. Copper-ion resistant E. coli and E. faecium cells suspended in 0.8% NaCl showed prolonged survival rates on electroplated copper surfaces with benzotriazole coating and thermal oxide coating compared to surfaces without anti-corrosion treatment. Control of surface corrosion affected the level of copper ion influx into bacterial cells which contributed directly to bacterial killing. PMID:21085951

Relation of serum γ-glutamyl transferase activity with copper in an adult population.

PubMed

Peng, You-Fan; Wang, Chun-Fang; Pan, Guo-Gang

2017-10-26

The aim of this study was to evaluate the relationship between serum γ-glutamyl transferase (γ-GGT) activity and serum copper in an adult population. We analyzed 281 adult subjects who regularly attended the physical examination center at the Affiliated Hospital of Youjiang Medical University for Nationalities. The demographic and laboratory data of the participants were divided into two groups according to the median of serum γ-GGT activity. Serum copper concentrations in individuals with higher γ-GGT levels were significantly increased compared with those with lower γ-GGT concentrations (9.9±2.41 vs. 11.2±3.36 μmol/L, p<0.001). There was a positive correlation between serum γ-GGT activity and copper in all eligible subjects (r=0.198, p=0.001). Further, serum γ-GGT maintained a positive correlation with serum copper in both males and females (r=0.322, p<0.001; r=0.230, p=0.010). The results of multiple linear regression analysis showed that serum γ-GGT maintained a significantly positive correlation with copper after adjusting for multiple potential confounders (b=0.464, p=0.001). This study suggests that serum γ-GGT activity is correlated with copper in the study population, indicating that serum γ-GGT may be a biomarker to evaluate serum copper levels in an adult population.

Demystifying Controlling Copper Corrosion

EPA Science Inventory

The LCR systematically misses the highest health and corrosion risk sites for copper. Additionally, there are growing concerns for WWTP copper in sludges and discharge levels. There are many corrosion control differences between copper and lead. This talk explains the sometimes c...

Yeast Starter as a Biotechnological Tool for Reducing Copper Content in Wine

PubMed Central

Capece, Angela; Romaniello, Rossana; Scrano, Laura; Siesto, Gabriella; Romano, Patrizia

2018-01-01

Copper is widely used in agriculture as a traditional fungicide in organic farming to control downy mildew on grapes, consequently it is possible to find this metal during all stages of the vinification process. Low amounts of copper play a key role on the function of key cell enzymes, whereas excess quantities can exert amount-dependent cytotoxicity, resulting in general cellular damage. Nowadays the excessive copper ions in wines is removed by addition of adsorbents, but these additives can influence the sensory characteristics of wine, as well as detrimental to the health of consumers. It is well known that high concentrations of Cu2+ can be toxic to yeasts, inhibiting growth and activity, causing sluggish fermentation and reducing alcohol production. In this study, 47 S. cerevisiae strains were tested for copper tolerance by two different tests, growth on copper added medium and fermentative activity in copper added grape must. The results obtained by the two different tests were comparable and the high strain variability found was used to select four wild strains, possessing this characteristic at the highest (PP1-13 and A20) and the lowest level (MPR2-24 and A13). The selected strains were tested in synthetic and natural grape must fermentation for ability to reduce copper content in wine. The determination of copper content in wines and yeast cells revealed that at the lowest copper residual in wine corresponded the highest content in yeast cells, indicating a strong strain ability to reduce the copper content in wine. This effect was inversely correlated with strain copper resistance and the most powerful strain in copper reduction was the most sensitive strain, MPR2-24. This wild strain was finally tested as starter culture in cellar pilot scale fermentation in comparison to a commercial starter, confirming the behavior exhibited at lab scale. The use of this wild strain to complete the alcoholic fermentation and remove the copper from wine represents a

Featured Article: Effect of copper on nuclear translocation of copper chaperone for superoxide dismutase-1

PubMed Central

Wang, Lin; Ge, Yan

2016-01-01

Copper chaperone for superoxide dismutase-1 (CCS-1), facilitating copper insertion into superoxide dismutase 1 (SOD-1), is present in the nucleus. However, it is unknown how CCS-1 is translocated to the nucleus. The present study was undertaken to determine the effect of copper on nuclear translocation of CCS-1. Human umbilical vein endothelial cells (HUVECs) were subjected to hypoxia, causing an increase in both copper and CCS-1 in the nucleus. Treatment with tetraethylenepentamine (TEPA) not only decreased the total cellular concentration and the nuclear translocation of copper, but also completely suppressed the entry of CCS-1 to the nucleus. On the other hand, siRNA targeting CCS-1 neither inhibited the increase in total concentrations nor blocked the nuclear translocation of copper. This study thus demonstrates that under hypoxia condition, both copper and CCS-1 are transported to the nucleus. The nuclear translocation of CCS-1 is copper dependent, but the nuclear translocation of copper could take place alternatively in a CCS-1-independent pathway. PMID:27190267

The copper-transporting ATPase pump and its potential role in copper-tolerance

Treesearch

Katie Ohno; C.A. Clausen; Frederick Green; G. Stanosz

2016-01-01

Copper-tolerant brown-rot decay fungi exploit intricate mechanisms to neutralize the efficacy of copper-containing preservative formulations. The production and accumulation oxalate is the most widely recognized theory regarding the mechanism of copper-tolerance in these fungi. The role of oxalate, however, may be only one part of a series of necessary components...

Hybrid Fiber/Copper LAN Meets School's 25-Year Networking Requirements.

ERIC Educational Resources Information Center

Petruso, Sam; Humes, Vince

1994-01-01

Describes an innovative new curriculum being implemented at Walnut Creek Middle School (Pennsylvania) and an advanced networked computer environment that supports it now and will also meet future needs. Topics addressed include physical facilities; networking goals, both short-term and long-term; fiber-optic cable versus copper; and future…

Experimental Consequences of Mottness in High-Temperature Copper-Oxide Superconductors

ERIC Educational Resources Information Center

Chakraborty, Shiladitya

2009-01-01

It has been more than two decades since the copper-oxide high temperature superconductors were discovered. However, building a satisfactory theoretical framework to study these compounds still remains one of the major challenges in condensed matter physics. In addition to the mechanism of superconductivity, understanding the properties of the…

Copper homeostasis in grapevine: functional characterization of the Vitis vinifera copper transporter 1.

PubMed

Martins, Viviana; Bassil, Elias; Hanana, Mohsen; Blumwald, Eduardo; Gerós, Hernâni

2014-07-01

The Vitis vinifera copper transporter 1 is capable of self-interaction and mediates intracellular copper transport. An understanding of copper homeostasis in grapevine (Vitis vinifera L.) is particularly relevant to viticulture in which copper-based fungicides are intensively used. In the present study, the Vitis vinifera copper transporter 1 (VvCTr1), belonging to the Ctr family of copper transporters, was cloned and functionally characterized. Amino acid sequence analysis showed that VvCTr1 monomers are small peptides composed of 148 amino acids with 3 transmembrane domains and several amino acid residues typical of Ctr transporters. Bimolecular fluorescence complementation (BiFC) demonstrated that Ctr monomers are self-interacting and subcellular localization studies revealed that VvCTr1 is mobilized via the trans-Golgi network, through the pre-vacuolar compartment and located to the vacuolar membrane. The heterologous expression of VvCTr1 in a yeast strain lacking all Ctr transporters fully rescued the phenotype, while a deficient complementation was observed in a strain lacking only plasma membrane-bound Ctrs. Given the common subcellular localization of VvCTr1 and AtCOPT5 and the highest amino acid sequence similarity in comparison to the remaining AtCOPT proteins, Arabidopsis copt5 plants were stably transformed with VvCTr1. The impairment in root growth observed in copt5 seedlings in copper-deficient conditions was fully rescued by VvCTr1, further supporting its involvement in intracellular copper transport. Expression studies in V. vinifera showed that VvCTr1 is mostly expressed in the root system, but transcripts were also present in leaves and stems. The functional characterization of VvCTr-mediated copper transport provides the first step towards understanding the physiological and molecular responses of grapevines to copper-based fungicides.

Ditching Tests of a 1/8-Scale Model of the Chance Vought XF6U-1 Airplane, TED No. NACA DE319

NASA Technical Reports Server (NTRS)

Fisher, Lloyd J., Jr.; McBride, Ellis E.

1953-01-01

Tests were made with a 1/8-scale dynamically similar model of the Chance Vought XF6U-1 airplane to study its behavior when ditched. The model was ditched in calm water at the Langley tank no. 2 monorail. Various landing attitudes, speeds, and conditions of damage were simulated. The behavior of the model was determined from visual observations, by recording time histories of the accelerations, and by taking motion pictures of the ditchings. From the results of the tests it was concluded that the airplane should be ditched at the near-stall, tail-down attitude (12 deg). The flaps should be fully extended to obtain the lowest possible landing speed. The wing-tip tanks should be jettisoned. The underside of the fuselage will be critically damaged in a ditching and the airplane will dive violently after a run of about three fuselage lengths. Maximum longitudinal decelerations up to about 7g and maximum vertical accelerations up to about 5g will be encountered.

The effect of the cation substitution on the structural and vibrational properties of Cs2NaGaxSc1-xF6 solid solution

NASA Astrophysics Data System (ADS)

Doriguetto, A. C.; Boschi, T. M.; Pizani, P. S.; Mascarenhas, Y. P.; Ellena, J.

2004-08-01

Raman scattering and x-ray diffration were used to characterize the structural and vibrational properties of the Cs2NaGaxSc1-xF6 solid solutions, for x ranging from 0.0 to 1.0. The Raman spectra, taken at room and low temperature, allow us to follow the phase evolution in detail and indicate the breaking of the local symmetry since low Ga concentration levels. Five compositions were studied by x-ray diffraction: x=0.0, 0.2, 0.5, 0.8, and 1.0. A cubic space group, Fm3¯m, was found to x=0.0 and x=0.2 and a trigonal one was found to x=0.5, 0.8, and 1.0. Details of both phases are presented and the correlation between x-ray diffraction and Raman scattering is discussed.

High-Speed Wind-Tunnel Investigation of the Longitudinal Stability and Control Characteristics of a 0.10-Scale Model of the Grumman XF9F-2 Airplane, TED No. NACA DE301

NASA Technical Reports Server (NTRS)

Polhamus, Edward C.; King, Thomas J., Jr.

1948-01-01

An investigation was made in the Langley high-speed 7-by 10-foot tunnel to determine the high-speed longitudinal stability end con&o1 characteristics of a 0.01-scale model of the Grumman XF9F-2 airplane in the Mach number range from 0.40 to 0.85. The results indicated that the lift and drag force breaks occurred at a Mach number of about 0.76. The aerodynamic-center position moved rearward after the force break and control position stability was present for all Mach numbers up to a Mach number of 0.80.

Copper-complexing ligands produced by an intact estuarine microbial community in response to copper stress.

NASA Astrophysics Data System (ADS)

Bingham, J.; Dryden, C.; Gordon, A.

2002-12-01

Copper is both an important nutrient and a pollutant in the marine environment. By studying the interactions between microorganisms and copper in the Elizabeth River (VA), home to a major Naval Base, we field tested the hypothesis that picoplankton and/or bacterioplankton produce strong, copper-complexing ligands in response to elevated copper concentrations. A simple light/ dark test was used to distinguish between heterotrophic and phototrophic ligand production. Samples were bottled and moored, submerged one meter, for a week. Direct counts using DAPI stain and epiflourescence were conducted to find concentrations of picoplankton and bacterioplankton. Using cathodic stripping voltammetry, we found the total copper concentrations, and then from a titration of the ligands by copper, the ligand concentrations and conditional stability constants were obtained. The Elizabeth River naturally had between 10-20 nM total dissolved copper concentrations. However when copper complexation was considered we found that the levels of bio-available Cu(II) ions were much lower. In fact in the natural samples the levels were not high enough to affect the relative reproductive rates of several microorganisms. Naturally there was a 50 nM "buffer zone" of ligand to total dissolved copper concentration. Furthermore, when stressed with excess copper, healthy picoplankton produced enough ligand to alleviate toxicity, and rebuild the buffer zone. However bacterioplankton only produced enough ligand so that they were no longer affected. Therefore, intact estuarine communities regulate copper bioavailability and toxicity with ligand production.

Impact of copper ligand mutations on a cupredoxin with a green copper center.

PubMed

Roger, Magali; Sciara, Giuliano; Biaso, Frédéric; Lojou, Elisabeth; Wang, Xie; Bauzan, Marielle; Giudici-Orticoni, Marie-Thérèse; Vila, Alejandro J; Ilbert, Marianne

2017-05-01

Mononuclear cupredoxins contain a type 1 copper center with a trigonal or tetragonal geometry usually maintained by four ligands, a cystein, two histidines and a methionine. The recent discovery of new members of this family with unusual properties demonstrates, however, the versatility of this class of proteins. Changes in their ligand set lead to drastic variation in their metal site geometry and in the resulting spectroscopic and redox features. In our work, we report the identification of the copper ligands in the recently discovered cupredoxin AcoP. We show that even though AcoP possesses a classical copper ligand set, it has a highly perturbed copper center. In depth studies of mutant's properties suggest a high degree of constraint existing in the copper center of the wild type protein and even the addition of exogenous ligands does not lead to the reconstitution of the initial copper center. Not only the chemical nature of the axial ligand but also constraints brought by its covalent binding to the protein backbone might be critical to maintain a green copper site with high redox potential. This work illustrates the importance of experimentally dissecting the molecular diversity of cupredoxins to determine the molecular determinants responsible for their copper center geometry and redox potential. Copyright © 2017 Elsevier B.V. All rights reserved.

A novel anti-influenza copper oxide containing respiratory face mask.

PubMed

Borkow, Gadi; Zhou, Steve S; Page, Tom; Gabbay, Jeffrey

2010-06-25

Protective respiratory face masks protect the nose and mouth of the wearer from vapor drops carrying viruses or other infectious pathogens. However, incorrect use and disposal may actually increase the risk of pathogen transmission, rather than reduce it, especially when masks are used by non-professionals such as the lay public. Copper oxide displays potent antiviral properties. A platform technology has been developed that permanently introduces copper oxide into polymeric materials, conferring them with potent biocidal properties. We demonstrate that impregnation of copper oxide into respiratory protective face masks endows them with potent biocidal properties in addition to their inherent filtration properties. Both control and copper oxide impregnated masks filtered above 99.85% of aerosolized viruses when challenged with 5.66+/-0.51 and 6.17+/-0.37 log(10)TCID(50) of human influenza A virus (H1N1) and avian influenza virus (H9N2), respectively, under simulated breathing conditions (28.3 L/min). Importantly, no infectious human influenza A viral titers were recovered from the copper oxide containing masks within 30 minutes (< or = 0.88 log(10)TCID(50)), while 4.67+/-1.35 log(10)TCID(50) were recovered from the control masks. Similarly, the infectious avian influenza titers recovered from the copper oxide containing masks were < or = 0.97+/-0.01 log(10)TCID(50) and from the control masks 5.03+/-0.54 log(10)TCID(50). The copper oxide containing masks successfully passed Bacterial Filtration Efficacy, Differential Pressure, Latex Particle Challenge, and Resistance to Penetration by Synthetic Blood tests designed to test the filtration properties of face masks in accordance with the European EN 14683:2005 and NIOSH N95 standards. Impregnation of copper oxide into respiratory protective face masks endows them with potent anti-influenza biocidal properties without altering their physical barrier properties. The use of biocidal masks may significantly reduce the risk

Removal of copper from ferrous scrap

DOEpatents

Blander, M.; Sinha, S.N.

1987-07-30

A process for removing copper from ferrous or other metal scrap in which the scrap is contacted with a polyvalent metal sulfide slag in the presence of an excess of copper-sulfide forming additive to convert the copper to copper sulfide which is extracted into the slag to provide a ratio of copper in the slag to copper in the metal scrap of at least about 10.

Removal of copper from ferrous scrap

DOEpatents

Blander, M.; Sinha, S.N.

1990-05-15

A process for removing copper from ferrous or other metal scrap in which the scrap is contacted with a polyvalent metal sulfide slag in the presence of an excess of copper-sulfide forming additive to convert the copper to copper sulfide which is extracted into the slag to provide a ratio of copper in the slag to copper in the metal scrap of at least about 10.

Removal of copper from ferrous scrap

DOEpatents

Blander, Milton; Sinha, Shome N.

1990-01-01

A process for removing copper from ferrous or other metal scrap in which the scrap is contacted with a polyvalent metal sulfide slag in the presence of an excess of copper-sulfide forming additive to convert the copper to copper sulfide which is extracted into the slag to provide a ratio of copper in the slag to copper in the metal scrap of at least about 10.

Effects of stimulation of copper bioleaching on microbial community in vineyard soil and copper mining waste.

PubMed

Andreazza, Robson; Okeke, Benedict C; Pieniz, Simone; Bortolon, Leandro; Lambais, Márcio R; Camargo, Flávio A O

2012-04-01

Long-term copper application in vineyards and copper mining activities cause heavy metal pollution sites. Such sites need remediation to protect soil and water quality. Bioremediation of contaminated areas through bioleaching can help to remove copper ions from the contaminated soils. Thus, the aim of this work was to evaluate the effects of different treatments for copper bioleaching in two diverse copper-contaminated soils (a 40-year-old vineyard and a copper mining waste) and to evaluate the effect on microbial community by applying denaturing gradient gel electrophoresis (DGGE) of 16S ribosomal DNA amplicons and DNA sequence analysis. Several treatments with HCl, H(2)SO(4), and FeSO(4) were evaluated by stimulation of bioleaching of copper in the soils. Treatments and extractions using FeSO(4) and H(2)SO(4) mixture at 30°C displayed more copper leaching than extractions with deionized water at room temperature. Treatment with H(2)SO(4) supported bioleaching of as much as 120 mg kg(-1) of copper from vineyard soil after 115 days of incubation. DGGE analysis of the treatments revealed that some treatments caused greater diversity of microorganisms in the vineyard soil compared to the copper mining waste. Nucleotide Blast of PCR-amplified fragments of 16S rRNA gene bands from DGGE indicated the presence of Rhodobacter sp., Silicibacter sp., Bacillus sp., Paracoccus sp., Pediococcus sp., a Myxococcales, Clostridium sp., Thiomonas sp., a firmicute, Caulobacter vibrioides, Serratia sp., and an actinomycetales in vineyard soil. Contrarily, Sphingomonas was the predominant genus in copper mining waste in most treatments. Paracoccus sp. and Enterobacter sp. were also identified from DGGE bands of the copper mining waste. Paracoccus species is involved in the copper bioleaching by sulfur oxidation system, liberating the copper bounded in the soils and hence promoting copper bioremediation. Results indicate that stimulation of bioleaching with a combination of FeSO(4

Reflectometry-Ellipsometry Reveals Thickness, Growth Rate, and Phase Composition in Oxidation of Copper.

PubMed

Diaz Leon, Juan J; Fryauf, David M; Cormia, Robert D; Zhang, Min-Xian Max; Samuels, Kathryn; Williams, R Stanley; Kobayashi, Nobuhiko P

2016-08-31

The oxidation of copper is a complicated process. Copper oxide develops two stable phases at room temperature and standard pressure (RTSP): cuprous oxide (Cu2O) and cupric oxide (CuO). Both phases have different optical and electrical characteristics that make them interesting for applications such as solar cells or resistive switching devices. For a given application, it is necessary to selectively control oxide thickness and cupric/cuprous oxide phase volume fraction. The thickness and composition of a copper oxide film growing on the surface of copper widely depend on the characteristics of as-deposited copper. In this Research Article, two samples, copper films prepared by two different deposition techniques, electron-beam evaporation and sputtering, were studied. As the core part of the study, the formation of the oxidized copper was analyzed routinely over a period of 253 days using spectroscopic polarized reflectometry-spectroscopic ellipsometry (RE). An effective medium approximation (EMA) model was used to fit the RE data. The RE measurements were complemented and validated by using X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and X-ray diffraction (XRD). Our results show that the two samples oxidized under identical laboratory ambient conditions (RTSP, 87% average relative humidity) developed unique oxide films following an inverse-logarithmic growth rate with thickness and composition different from each other over time. Discussion is focused on the ability of RE to simultaneously extract thickness (i.e., growth rate) and composition of copper oxide films and on plausible physical mechanisms responsible for unique oxidation habits observed in the two copper samples. It appears that extended surface characteristics (i.e., surface roughness and grain boundaries) and preferential crystalline orientation of as-deposited polycrystalline copper films control the growth kinetics of the copper oxide film. Analysis based on a noncontact

Preparation of graphite dispersed copper composite on copper plate with CO2 laser

NASA Astrophysics Data System (ADS)

Yokoyama, S.; Ishikawa, Y.; Muizz, M. N. A.; Hisyamudin, M. N. N.; Nishiyama, K.; Sasano, J.; Izaki, M.

2018-01-01

It was tried in this work to prepare the graphite dispersed copper composite locally on a copper plate with a CO2 laser. The objectives of this study were to clear whether copper graphite composite was prepared on a copper plate and how the composite was prepared. The carbon content at the laser spot decreased with the laser irradiation time. This mainly resulted from the elimination by the laser trapping. The carbon content at the outside of the laser spot increased with time. Both the laser ablation and the laser trapping did not act on the graphite particles at the outside of the laser spot. Because the copper at the outside of the laser spot melted by the heat conduction from the laser spot, the particles were fixed by the wetting. However, the graphite particles were half-floated on the copper plate. The Vickers hardness decreased with an increase with laser irradiation time because of annealing.

Copper Recovery from Yulong Complex Copper Oxide Ore by Flotation and Magnetic Separation

NASA Astrophysics Data System (ADS)

Han, Junwei; Xiao, Jun; Qin, Wenqing; Chen, Daixiong; Liu, Wei

2017-09-01

A combined process of flotation and high-gradient magnetic separation was proposed to utilize Yulong complex copper oxide ore. The effects of particle size, activators, Na2S dosage, LA (a mixture of ammonium sulfate and ethylenediamine) dosage, activating time, collectors, COC (a combination collector of modified hydroxyl oxime acid and xanthate) dosage, and magnetic intensity on the copper recovery were investigated. The results showed that 74.08% Cu was recovered by flotation, while the average grade of the copper concentrates was 21.68%. Another 17.34% Cu was further recovered from the flotation tailing by magnetic separation at 0.8 T. The cumulative recovery of copper reached 91.42%. The modifier LA played a positive role in facilitating the sulfidation of copper oxide with Na2S, and the combined collector COC was better than other collectors for the copper flotation. This technology has been successfully applied to industrial production, and the results are consistent with the laboratory data.

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.

Antimicrobial Properties of Copper Nanoparticles and Amino Acid Chelated Copper Nanoparticles Produced by Using a Soya Extract.

PubMed

DeAlba-Montero, I; Guajardo-Pacheco, Jesús; Morales-Sánchez, Elpidio; Araujo-Martínez, Rene; Loredo-Becerra, G M; Martínez-Castañón, Gabriel-Alejandro; Ruiz, Facundo; Compeán Jasso, M E

2017-01-01

This paper reports a comparison of the antibacterial properties of copper-amino acids chelates and copper nanoparticles against Escherichia coli , Staphylococcus aureus , and Enterococcus faecalis . These copper-amino acids chelates were synthesized by using a soybean aqueous extract and copper nanoparticles were produced using as a starting material the copper-amino acids chelates species. The antibacterial activity of the samples was evaluated by using the standard microdilution method (CLSI M100-S25 January 2015). In the antibacterial activity assays copper ions and copper-EDTA chelates were included as references, so that copper-amino acids chelates can be particularly suitable for acting as an antibacterial agent, so they are excellent candidates for specific applications. Additionally, to confirm the antimicrobial mechanism on bacterial cells, MTT assay (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) was carried out. A significant enhanced antimicrobial activity and a specific strain were found for copper chelates over E. faecalis . Its results would eventually lead to better utilization of copper-amino acids chelate for specific application where copper nanoparticles can be not used.

Antimicrobial Properties of Copper Nanoparticles and Amino Acid Chelated Copper Nanoparticles Produced by Using a Soya Extract

PubMed Central

DeAlba-Montero, I.; Morales-Sánchez, Elpidio; Araujo-Martínez, Rene

2017-01-01

This paper reports a comparison of the antibacterial properties of copper-amino acids chelates and copper nanoparticles against Escherichia coli, Staphylococcus aureus, and Enterococcus faecalis. These copper-amino acids chelates were synthesized by using a soybean aqueous extract and copper nanoparticles were produced using as a starting material the copper-amino acids chelates species. The antibacterial activity of the samples was evaluated by using the standard microdilution method (CLSI M100-S25 January 2015). In the antibacterial activity assays copper ions and copper-EDTA chelates were included as references, so that copper-amino acids chelates can be particularly suitable for acting as an antibacterial agent, so they are excellent candidates for specific applications. Additionally, to confirm the antimicrobial mechanism on bacterial cells, MTT assay (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) was carried out. A significant enhanced antimicrobial activity and a specific strain were found for copper chelates over E. faecalis. Its results would eventually lead to better utilization of copper-amino acids chelate for specific application where copper nanoparticles can be not used. PMID:28286459

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.

Crystal structures of copper(II) chloride, copper(II) bromide, and copper(II) nitrate complexes with pyridine-2-carbaldehyde thiosemicarbazone

NASA Astrophysics Data System (ADS)

Chumakov, Yu. M.; Tsapkov, V. I.; Jeanneau, E.; Bairac, N. N.; Bocelli, G.; Poirier, D.; Roy, J.; Gulea, A. P.

2008-09-01

The crystal structures of chloro-(2-formylpyridinethiosemicarbazono)copper dimethyl sulfoxide solvate ( I), bromo-(2-formylpyridinethiosemicarbazono)copper ( II), and (2-formylpyridinethiosemicarbazono)copper(II) nitrate dimethyl sulfoxide solvate ( III) are determined using X-ray diffraction. In the crystals, complexes I and II form centrosymmetric dimers in which the thiosemicarbazone sulfur atom serves as a bridge and occupies the fifth coordination site of the copper atom of the neighboring complex related to the initial complex through the center of symmetry. In both cases, the coordination polyhedron of the complexing ion is a distorted tetragonal bipyramid. Complex III in the crystal structure forms polymer chains in which the copper atom of one complex forms the coordination bond with the thicarbamide nitrogen atom of the neighboring complex. In this structure, the coordination polyhedron of the central atom is an elongated tetragonal bipyramid. It is established that complexes I III at a concentration of 10-5 mol/l selectively inhibit the growth of 60 to 90 percent of the cancer tumor cells of the human myeloid leukemia (HL-60).

Aberrant expression of copper associated genes after copper accumulation in COMMD1-deficient dogs.

PubMed

Favier, Robert P; Spee, Bart; Fieten, Hille; van den Ingh, Ted S G A M; Schotanus, Baukje A; Brinkhof, Bas; Rothuizen, Jan; Penning, Louis C

2015-01-01

COMMD1-deficient dogs progressively develop copper-induced chronic hepatitis. Since high copper leads to oxidative damage, we measured copper metabolism and oxidative stress related gene products during development of the disease. Five COMMD1-deficient dogs were studied from 6 months of age over a period of five years. Every 6 months blood was analysed and liver biopsies were taken for routine histological evaluation (grading of hepatitis), rubeanic acid copper staining and quantitative copper analysis. Expression of genes involved in copper metabolism (COX17, CCS, ATOX1, MT1A, CP, ATP7A, ATP7B, ) and oxidative stress (SOD1, catalase, GPX1 ) was measured by qPCR. Due to a sudden death of two animals, the remaining three dogs were treated with d-penicillamine from 43 months of age till the end of the study. Presented data for time points 48, 54, and 60 months was descriptive only. A progressive trend from slight to marked hepatitis was observed at histology, which was clearly preceded by an increase in semi-quantitative copper levels starting at 12 months until 42 months of age. During the progression of hepatitis most gene products measured were transiently increased. Most prominent was the rapid increase in the copper binding gene product MT1A mRNA levels. This was followed by a transient increase in ATP7A and ATP7B mRNA levels. In the sequence of events, copper accumulation induced progressive hepatitis followed by a transient increase in gene products associated with intracellular copper trafficking and temporal activation of anti-oxidative stress mechanisms. Copyright © 2014 Elsevier GmbH. All rights reserved.

Post examination of copper ER sensors exposed to bentonite

NASA Astrophysics Data System (ADS)

Kosec, Tadeja; Kranjc, Andrej; Rosborg, Bo; Legat, Andraž

2015-04-01

Copper corrosion in saline solutions under oxic conditions is one of concerns for the early periods of disposal of spent nuclear fuel in deep geological repositories. The main aim of the study was to investigate the corrosion behaviour of copper during this oxic period. The corrosion rate of pure copper was measured by means of thin electrical resistance (ER) sensors that were placed in a test package containing an oxic bentonite/saline groundwater environment at room temperature for a period of four years. Additionally, the corrosion rate was monitored by electrochemical impedance spectroscopy (EIS) measurements that were performed on the same ER sensors. By the end of the exposure period the corrosion rate, as estimated by both methods, had dropped to approximately 1.0 μm/year. The corrosion rate was also estimated by the examination of metallographic cross sections. The post examination tests which were used to determine the type and extent of corrosion products included different spectroscopic techniques (XRD and Raman analysis). It was confirmed that the corrosion rate obtained by means of physical (ER) and electrochemical techniques (EIS) was consistent with that estimated from the metallographic cross section analysis. The corrosion products consisted of cuprous oxide and paratacamite, which was very abundant. From the types of attack it can be concluded that the investigated samples of copper in bentonite underwent uneven general corrosion.

Copper in diet

MedlinePlus

Diet - copper ... yeast are also sources of copper in the diet. ... day 9 to 13 years: 700 mcg/day Adolescents and adults Males and ... eat a balanced diet that contains a variety of foods from the ...

Copper atomic-scale transistors.

PubMed

Xie, Fangqing; Kavalenka, Maryna N; Röger, Moritz; Albrecht, Daniel; Hölscher, Hendrik; Leuthold, Jürgen; Schimmel, Thomas

2017-01-01

We investigated copper as a working material for metallic atomic-scale transistors and confirmed that copper atomic-scale transistors can be fabricated and operated electrochemically in a copper electrolyte (CuSO 4 + H 2 SO 4 ) in bi-distilled water under ambient conditions with three microelectrodes (source, drain and gate). The electrochemical switching-on potential of the atomic-scale transistor is below 350 mV, and the switching-off potential is between 0 and -170 mV. The switching-on current is above 1 μA, which is compatible with semiconductor transistor devices. Both sign and amplitude of the voltage applied across the source and drain electrodes ( U bias ) influence the switching rate of the transistor and the copper deposition on the electrodes, and correspondingly shift the electrochemical operation potential. The copper atomic-scale transistors can be switched using a function generator without a computer-controlled feedback switching mechanism. The copper atomic-scale transistors, with only one or two atoms at the narrowest constriction, were realized to switch between 0 and 1 G 0 ( G 0 = 2e 2 /h; with e being the electron charge, and h being Planck's constant) or 2 G 0 by the function generator. The switching rate can reach up to 10 Hz. The copper atomic-scale transistor demonstrates volatile/non-volatile dual functionalities. Such an optimal merging of the logic with memory may open a perspective for processor-in-memory and logic-in-memory architectures, using copper as an alternative working material besides silver for fully metallic atomic-scale transistors.

Copper atomic-scale transistors

PubMed Central

Kavalenka, Maryna N; Röger, Moritz; Albrecht, Daniel; Hölscher, Hendrik; Leuthold, Jürgen

2017-01-01

We investigated copper as a working material for metallic atomic-scale transistors and confirmed that copper atomic-scale transistors can be fabricated and operated electrochemically in a copper electrolyte (CuSO4 + H2SO4) in bi-distilled water under ambient conditions with three microelectrodes (source, drain and gate). The electrochemical switching-on potential of the atomic-scale transistor is below 350 mV, and the switching-off potential is between 0 and −170 mV. The switching-on current is above 1 μA, which is compatible with semiconductor transistor devices. Both sign and amplitude of the voltage applied across the source and drain electrodes (U bias) influence the switching rate of the transistor and the copper deposition on the electrodes, and correspondingly shift the electrochemical operation potential. The copper atomic-scale transistors can be switched using a function generator without a computer-controlled feedback switching mechanism. The copper atomic-scale transistors, with only one or two atoms at the narrowest constriction, were realized to switch between 0 and 1G 0 (G 0 = 2e2/h; with e being the electron charge, and h being Planck’s constant) or 2G 0 by the function generator. The switching rate can reach up to 10 Hz. The copper atomic-scale transistor demonstrates volatile/non-volatile dual functionalities. Such an optimal merging of the logic with memory may open a perspective for processor-in-memory and logic-in-memory architectures, using copper as an alternative working material besides silver for fully metallic atomic-scale transistors. PMID:28382242

Oxalic acid overproduction by copper-tolerant brown-rot basidiomycetes on southern yellow pine treated with copper-based preservatives

Treesearch

Carol A. Clausen; Frederick Green

2003-01-01

Accumulation of oxalic acid (OA) by brown-rot fungi and precipitation of copper oxalate crystals in wood decayed by copper-tolerant decay fungi has implicated OA in the mechanism of copper tolerance. Understanding the role of OA in copper tolerance is important due to an increasing reliance on copper-based wood preservatives. In this study, four copper-tolerant brown-...

Electrochemical Control of Copper Intercalation into Nanoscale Bi 2Se 3

DOE PAGES

Zhang, Jinsong; Sun, Jie; Li, Yanbin; ...

2017-02-20

Intercalation of exotic atoms or molecules into the layered materials remains an extensively investigated subject in current physics and chemistry. However, traditionally melt-growth and chemical interaction strategies are either limited by insufficiency of intercalant concentrations or destitute of accurate controllability. Here, we have developed a general electrochemical intercalation method to efficaciously regulate the concentration of zerovalent copper atoms into layered Bi 2Se 3, followed by comprehensive experimental characterization and analyses. Up to 57% copper atoms (Cu 6.7Bi 2Se 3) can be intercalated with no disruption to the host lattice. Meanwhile the unconventional resistance dip accompanied by a hysteresis loop belowmore » 40 K, as well as the emergence of new Raman peak in Cu xBi 2Se 3, is a distinct manifestation of the interplay between intercalated Cu atoms with Bi 2Se 3 host. Furthermore, our work demonstrates a new methodology to study fundamentally new and unexpected physical behaviors in intercalated metastable materials.« less

Lateral Stability Characteristics of a 1/8.33-Scale Powered Model of the Republic XF-12 Airplane

NASA Technical Reports Server (NTRS)

Pepper, Edward; Foster, Gerald V.

1947-01-01

The XF-12 airplane is a high-performance photo-reconnaissance aircraft designed for the Army Air Forces by the Republic Aviation Corporation. An investigation of a 1/8.33 - scale powered model was made in the Langley l9-foot pressure tunnel to obtain information relative to the aerodynamic design of the airplane. The model was tested with and without the original vertical tail. and with two revised tails. For the revised tail no. 1, the span of the original vertical .tail was increased about 15 percent and the portion of the vertical tail between the stabilizer and fuselage behind the rudder hinge line was allowed to deflect simultaneously with the main rudder. Revision no. 2 incorporated the increased span, but the lower rudder was locked in the neutral position. For all the tail arrangements investigated it was indicated that the airplane will possess positive effective dihedral and will be directionally stable regardless of flap or power condition. The rudder effectiveness is greater for the revised tails than for the original tail, but this is offset by the increase in directional stability caused by the revised tail. All the rudder arrangements appear inadequate in trimming out the resultant yawing moments at zero yaw in a take - off condition with the left-hand outboard propeller windmilling and the remaining engines developing take-off power.

Crossed-beam experiment for the scattering of low- and intermediate-energy electrons from BF{sub 3}: A comparative study with XF{sub 3} (X = C, N, and CH) molecules

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

Hoshino, M., E-mail: masami-h@sophia.ac.jp; Suga, A.; Kato, H.

2015-07-14

Absolute differential cross sections (DCSs) for electron interaction with BF{sub 3} molecules have been measured in the impact energy range of 1.5–200 eV and recorded over a scattering angle range of 15°–150°. These angular distributions have been normalized by reference to the elastic DCSs of the He atom and integrated by employing a modified phase shift analysis procedure to generate integral cross sections (ICSs) and momentum transfer cross sections (MTCSs). The calculations of DCSs and ICSs have been carried out using an independent atom model under the screening corrected additivity rule (IAM-SCAR). The present elastic DCSs have been found tomore » agree well with the results of IAM-SCAR calculation above 20 eV, and also with a recent Schwinger multichannel calculation below 30 eV. Furthermore, in the comparison with the XF{sub 3} (X = B, C, N, and CH) molecules, the elastic DCSs reveal a similar angular distribution which are approximately equal in magnitude from 30 to 200 eV. This feature suggests that the elastic scattering is dominated virtually by the 3-outer fluorine atoms surrounding the XF{sub 3} molecules. The vibrational DCSs have also been obtained in the energy range of 1.5–15 eV and vibrational analysis based on the angular correlation theory has been carried out to explain the nature of the shape resonances. Limited experiments on vibrational inelastic scattering confirmed the existence of a shape resonance with a peak at 3.8 eV, which is also observed in the vibrational ICS. Finally, the estimated elastic ICSs, MTCSs, as well as total cross sections are compared with the previous cross section data available.« less

Suppression of the cooperative Jahn-Teller distortion and its effect on the Raman octahedra-rotation modes of TbM n1 -xF exO3

NASA Astrophysics Data System (ADS)

Vilarinho, R.; Passos, D. J.; Queirós, E. C.; Tavares, P. B.; Almeida, A.; Weber, M. C.; Guennou, M.; Kreisel, J.; Moreira, J. Agostinho

2018-04-01

This work reports the changes in structure and lattice dynamics induced by substituting the Jahn-Teller-active M n3 + ion by the Jahn-Teller-inactive F e3 + in TbM n1 -xF exO3 over the full composition range. The structural analysis reveals that the amplitude of the cooperative Jahn-Teller distortion decreases linearly from x =0 (pure TbMn O3 ) to x =0.5 , where it is completely suppressed. We then correlate this evolution with the behavior of the Raman modes across the solid solution. In particular, we show that the Raman modes associated with the rotation of octahedra, whose wave number is commonly considered to scale linearly with the tilt angles in orthorhombic Pnma perovskites, are also sensitive to the amplitude of the Jahn-Teller distortion.

Speciation and leachability of copper in mine tailings from porphyry copper mining: influence of particle size.

PubMed

Hansen, Henrik K; Yianatos, Juan B; Ottosen, Lisbeth M

2005-09-01

Mine tailing from the El Teniente-Codelco copper mine situated in VI Region of Chile was analysed in order to evaluate the mobility and speciation of copper in the solid material. Mine tailing was sampled after the rougher flotation circuits, and the copper content was measured to 1150 mg kg (-1) dry matter. This tailing was segmented into fractions of different size intervals: 0-38, 38-45, 45-53, 53-75, 75-106, 106-150, 150-212, and >212 microm, respectively. Copper content determination, sequential chemical extraction, and desorption experiments were carried out for each size interval in order to evaluate the speciation of copper. It was found that the particles of smallest size contained 50-60% weak acid leachable copper, whereas only 32% of the copper found in largest particles could be leached in weak acid. Copper oxides and carbonates were the dominating species in the smaller particles, and the larger particles contained considerable amounts of sulphides.

Radioactivity at the Copper Creek copper lode prospect, Eagle district, east-central Alaska

USGS Publications Warehouse

Wedow, Helmuth; Tolbert, Gene Edward

1952-01-01

Investigation of radioactivity anomalies at the Copper Creek copper lode prospect, Eagle district, east-central Alaska, during 1949 disclosed that the radioactivity is associated with copper mineralization in highly metamorphosed sedimentary rocks. These rocks are a roof pendant in the Mesozoic "Charley River" batholith. The radioactivity is probably all due to uranium associated with bornite and malachite.

24-hour urine copper test

MedlinePlus

... medlineplus.gov/ency/article/003604.htm 24-hour urine copper test To use the sharing features on this page, please enable JavaScript. The 24-hour urine copper test measures the amount of copper in ...

Copper nanocoils synthesized through solvothermal method

PubMed Central

Liu, Yanjuan; Liu, Xiaowei; Zhan, Yongjie; Fan, Haiming; Lu, Yang

2015-01-01

Recently helical nanostructures such as nanosprings and nanocoils have drawn great interests in nanotechnology, due to their unique morphologies and physical properties, and they may be potential building blocks in sorts of electromechanical, magnetic, photoelectronic and plasmonic devices at micro/nanoscales. In this report, multi-turns copper nanocoils were synthesized through a modified solvothermal method, in which the mixture of water and N-methyl-2-pyrrolidone (NMP) were selected as reaction medium and copolymer poly(1-vinylpyrrolidone-co-vinyl acetate) (PVP/VA 64E) as reductant. In the liquid solution, nanosprings could be formed from relaxed nanocoils and demonstrated high elasticity. These nanocoils and nanosprings are of single crystalline structure, with the characteristics wire diameters ranging from tens to a few hundreds of nanometers and the ring/coil diameters mostly ~10–35 microns. Their growth and deformation mechanisms were then investigated and discussed along with that of previously reported single-turn copper nanorings. This work could be of importance for researchers working on synthesis and applications of novel 1-D helical nanomaterials and their functional devices. PMID:26607386

Free-Spinning-Tunnel Tests of a 1/24-Scale Model of the Grumman XF9F-2 Airplane, TED No. NACA DE 317

NASA Technical Reports Server (NTRS)

Berman, Theodore

1948-01-01

An investigation of the spin and recovery characteristics of a scale model of the Grumman XF9F-2 airplane has been conducted in the Langley 20-foot free-spinning tunnel. The effects of control settings and movements on the erect and inverted spin and recovery characteristics of the model in the flight loading were determined. The investigation also included spin-recovery-parachute, pilot-escape, and rudder-pedal- . force tests. The recovery characteristics of the model were satisfactory for all configurations tested. Spins for the normal control configuration were oscillatory in roll and yaw. Deflecting the leading-edge flaps or the dive brakes did not change the spin and recovery characteristics of the model noticeably. A 10.0-foot tail parachute or a 6.0-foot wing-tip parachute (drag coefficient of 0.75) was found to be effective for recoveries from demonstration spins. The rudder forces in the spin appeared to be within the capabilities of the pilot.

Porins Increase Copper Susceptibility of Mycobacterium tuberculosis

PubMed Central

Speer, Alexander; Rowland, Jennifer L.; Haeili, Mehri; Niederweis, Michael

2013-01-01

Copper resistance mechanisms are crucial for many pathogenic bacteria, including Mycobacterium tuberculosis, during infection because the innate immune system utilizes copper ions to kill bacterial intruders. Despite several studies detailing responses of mycobacteria to copper, the pathways by which copper ions cross the mycobacterial cell envelope are unknown. Deletion of porin genes in Mycobacterium smegmatis leads to a severe growth defect on trace copper medium but simultaneously increases tolerance for copper at elevated concentrations, indicating that porins mediate copper uptake across the outer membrane. Heterologous expression of the mycobacterial porin gene mspA reduced growth of M. tuberculosis in the presence of 2.5 μM copper by 40% and completely suppressed growth at 15 μM copper, while wild-type M. tuberculosis reached its normal cell density at that copper concentration. Moreover, the polyamine spermine, a known inhibitor of porin activity in Gram-negative bacteria, enhanced tolerance of M. tuberculosis for copper, suggesting that copper ions utilize endogenous outer membrane channel proteins of M. tuberculosis to gain access to interior cellular compartments. In summary, these findings highlight the outer membrane as the first barrier against copper ions and the role of porins in mediating copper uptake in M. smegmatis and M. tuberculosis. PMID:24013632

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.

Bacterial copper storage proteins.

PubMed

Dennison, Christopher; David, Sholto; Lee, Jaeick

2018-03-30

Copper is essential for most organisms as a cofactor for key enzymes involved in fundamental processes such as respiration and photosynthesis. However, copper also has toxic effects in cells, which is why eukaryotes and prokaryotes have evolved mechanisms for safe copper handling. A new family of bacterial proteins uses a Cys-rich four-helix bundle to safely store large quantities of Cu(I). The work leading to the discovery of these proteins, their properties and physiological functions, and how their presence potentially impacts the current views of bacterial copper handling and use are discussed in this review. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

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

The importance of surface functional groups in the adsorption of copper onto walnut shell derived activated carbon.

PubMed

Xie, Ruzhen; Jin, Yan; Chen, Yao; Jiang, Wenju

2017-12-01

In this study, activated carbon (AC) was prepared from walnut shell using chemical activation. The surface chemistry of the prepared AC was modified by introducing or blocking certain functional groups, and the role of the different functional groups involved in the copper uptake was investigated. The structural and chemical heterogeneity of the produced carbons are characterized by Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy, Boehm titration method and N 2 /77 K adsorption isotherm analysis. The equilibrium and the kinetics of copper adsorption onto AC were studied. The results demonstrated that the functional groups on AC played an important role in copper uptake. Among various surface functional groups, the oxygen-containing group was found to play a critical role in the copper uptake, and oxidation is the most effective way to improve Cu (II) adsorption onto AC. Ion-exchange was identified to be the dominant mechanism in the copper uptake by AC. Some other types of interactions, like complexation, were also proven to be involved in the adsorption process, while physical force was found to play a small role in the copper uptake. The regeneration of copper-loaded AC and the recovery of copper were also studied to evaluate the reusability of the oxidized AC.

High adherence copper plating process

DOEpatents

Nignardot, Henry

1993-01-01

A process for applying copper to a substrate of aluminum or steel by electrodeposition and for preparing an aluminum or steel substrate for electrodeposition of copper. Practice of the invention provides good adhesion of the copper layer to the substrate.

COPPER RESEARCH UPDATE

EPA Science Inventory

This presentation provides an update and overview of new research results and remaining research needs with respect to copper corrosion control issues. The topics to be covered include: occurrence of elevated copper release in systems that meet the Action Level; impact of water c...

Diabetic cardiomyopathy is associated with defective myocellular copper regulation and both defects are rectified by divalent copper chelation

PubMed Central

2014-01-01

Background Heart disease is the leading cause of death in diabetic patients, and defective copper metabolism may play important roles in the pathogenesis of diabetic cardiomyopathy (DCM). The present study sought to determine how myocardial copper status and key copper-proteins might become impaired by diabetes, and how they respond to treatment with the Cu (II)-selective chelator triethylenetetramine (TETA) in DCM. Methods Experiments were performed in Wistar rats with streptozotocin (STZ)-induced diabetes with or without TETA treatment. Cardiac function was analyzed in isolated-perfused working hearts, and myocardial total copper content measured by particle-induced x-ray emission spectroscopy (PIXE) coupled with Rutherford backscattering spectrometry (RBS). Quantitative expression (mRNA and protein) and/or activity of key proteins that mediate LV-tissue-copper binding and transport, were analyzed by combined RT-qPCR, western blotting, immunofluorescence microscopy, and enzyme activity assays. Statistical analysis was performed using Student’s t-tests or ANOVA and p-values of < 0.05 have been considered significant. Results Left-ventricular (LV) copper levels and function were severely depressed in rats following 16-weeks’ diabetes, but both were unexpectedly normalized 8-weeks after treatment with TETA was instituted. Localized myocardial copper deficiency was accompanied by decreased expression and increased polymerization of the copper-responsive transition-metal-binding metallothionein proteins (MT1/MT2), consistent with impaired anti-oxidant defences and elevated susceptibility to pro-oxidant stress. Levels of the high-affinity copper transporter-1 (CTR1) were depressed in diabetes, consistent with impaired membrane copper uptake, and were not modified by TETA which, contrastingly, renormalized myocardial copper and increased levels and cell-membrane localization of the low-affinity copper transporter-2 (CTR2). Diabetes also lowered indexes of

Preparation of graphite dispersed copper composite with intruding graphite particles in copper plate

NASA Astrophysics Data System (ADS)

Noor, Abdul Muizz Mohd; Ishikawa, Yoshikazu; Yokoyama, Seiji

2017-01-01

In this study, it was attempted that copper-graphite composite was prepared locally on the surface of a copper plate with using a spot welding machine. Experiments were carried out with changing the compressive load, the repetition number of the compression and the electrical current in order to study the effect of them on carbon content and Vickers hardness on the copper plate surface. When the graphite was pushed into copper plate only with the compressive load, the composite was mainly hardened by the work hardening. The Vickers hardness increased linearly with an increase in the carbon content. When an electrical current was energized through the composite at the compression, the copper around the graphite particles were heated to the temperature above approximately 2100 K and melted. The graphite particles partially or entirely dissolved into the melt. The graphite particles were precipitated from the melt under solidification. In addition, this high temperature caused the improvement of wetting of copper to graphite. This high temperature caused the annealing, and reduced the Vickers hardness. Even in this case, the Vickers hardness increased with an increase in the carbon content. This resulted from the dispersion hardening.

Canine Models for Copper Homeostasis Disorders.

PubMed

Wu, Xiaoyan; Leegwater, Peter A J; Fieten, Hille

2016-02-04

Copper is an essential trace nutrient metal involved in a multitude of cellular processes. Hereditary defects in copper metabolism result in disorders with a severe clinical course such as Wilson disease and Menkes disease. In Wilson disease, copper accumulation leads to liver cirrhosis and neurological impairments. A lack in genotype-phenotype correlation in Wilson disease points toward the influence of environmental factors or modifying genes. In a number of Non-Wilsonian forms of copper metabolism, the underlying genetic defects remain elusive. Several pure bred dog populations are affected with copper-associated hepatitis showing similarities to human copper metabolism disorders. Gene-mapping studies in these populations offer the opportunity to discover new genes involved in copper metabolism. Furthermore, due to the relatively large body size and long life-span of dogs they are excellent models for development of new treatment strategies. One example is the recent use of canine organoids for disease modeling and gene therapy of copper storage disease. This review addresses the opportunities offered by canine genetics for discovery of genes involved in copper metabolism disorders. Further, possibilities for the use of dogs in development of new treatment modalities for copper storage disorders, including gene repair in patient-derived hepatic organoids, are highlighted.

Canine Models for Copper Homeostasis Disorders

PubMed Central

Wu, Xiaoyan; Leegwater, Peter A. J.; Fieten, Hille

2016-01-01

Copper is an essential trace nutrient metal involved in a multitude of cellular processes. Hereditary defects in copper metabolism result in disorders with a severe clinical course such as Wilson disease and Menkes disease. In Wilson disease, copper accumulation leads to liver cirrhosis and neurological impairments. A lack in genotype-phenotype correlation in Wilson disease points toward the influence of environmental factors or modifying genes. In a number of Non-Wilsonian forms of copper metabolism, the underlying genetic defects remain elusive. Several pure bred dog populations are affected with copper-associated hepatitis showing similarities to human copper metabolism disorders. Gene-mapping studies in these populations offer the opportunity to discover new genes involved in copper metabolism. Furthermore, due to the relatively large body size and long life-span of dogs they are excellent models for development of new treatment strategies. One example is the recent use of canine organoids for disease modeling and gene therapy of copper storage disease. This review addresses the opportunities offered by canine genetics for discovery of genes involved in copper metabolism disorders. Further, possibilities for the use of dogs in development of new treatment modalities for copper storage disorders, including gene repair in patient-derived hepatic organoids, are highlighted. PMID:26861285

Transpassive Dissolution of Copper and Rapid Formation of Brilliant Colored Copper Oxide Films

NASA Astrophysics Data System (ADS)

Fredj, Narjes; Burleigh, T. David; New Mexico Tech Team

2014-03-01

This investigation describes an electrochemical technique for growing adhesive copper oxide films on copper with attractive colors ranging from gold-brown to pearl with intermediate colors from red violet to gold green. The technique consists of anodically dissolving copper at transpassive potentials in hot sodium hydroxide, and then depositing brilliant color films of Cu2O onto the surface of copper after the anodic potential has been turned off. The color of the copper oxide film depends on the temperature, the anodic potential, the time t1 of polarization, and the time t2, which is the time of immersion after potential has been turned off. The brilliant colored films were characterized using glancing angle x-ray diffraction, and the film was found to be primarily Cu2O. Cyclic voltammetry, chronopotentiometry, scanning electron microscopy, and x-ray photoelectron spectroscopy were also used to characterize these films.

Lateral Stability and Control Measurements of a 0.0858-Scale Model of the Lockheed XF-104 Airplane at Transonic Speeds

NASA Technical Reports Server (NTRS)

Arabian, Donald D.; Schmeer, James W.

1955-01-01

An investigation of the lateral stability and control effectiveness of a 0.0858-scale model of the Lockheed XF-104 airplane has been conducted in the Langley 16-foot transonic tunnel. The model has a low aspect ratio, 3.4-percent-thick wing with negative dihedral. The horizontal tail is located on top of the vertical tail. The investigation was made through a Mach number range of 0.80 to 1.06 at sideslip angles of -5 deg. to 5 deg. and angles of attack from 0 deg. to 16 deg. The control effectiveness of the aileron, rudder, and yaw damper were determined through the Mach number and angle-of-attack range. The results of the investigation indicated that the directional stability derivative was stable and that positive effective dihedral existed throughout the lift-coefficient range and Mach number range tested. The total aileron effectiveness, which in general produced favorable yaw with rolling moment, remained fairly constant for lift coefficients up to about 0.8 for the Mach number range tested. Yawing-moment effectiveness of the rudder changed little through the Mach number range. However, the yaw damper effectiveness decreased about 30 percent at the intermediate test Mach numbers.

Joining of alumina via copper/niobium/copper interlayers

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

Marks, Robert A.; Chapman, Daniel R.; Danielson, David T.

2000-03-15

Alumina has been joined at 1150 degrees C and 1400 degrees C using multilayer copper/niobium/copper interlayers. Four-point bend strengths are sensitive to processing temperature, bonding pressure, and furnace environment (ambient oxygen partial pressure). Under optimum conditions, joints with reproducibly high room temperature strengths (approximately equal 240 plus/minus 20 MPa) can be produced; most failures occur within the ceramic. Joints made with sapphire show that during bonding an initially continuous copper film undergoes a morphological instability, resulting in the formation of isolated copper-rich droplets/particles at the sapphire/interlayer interface, and extensive regions of direct bonding between sapphire and niobium. For optimized aluminamore » bonds, bend tests at 800 degrees C-1100 degrees C indicate significant strength is retained; even at the highest test temperature, ceramic failure is observed. Post-bonding anneals at 1000 degrees C in vacuum or in gettered argon were used to assess joint stability and to probe the effect of ambient oxygen partial pressure on joint characteristics. Annealing in vacuum for up to 200 h causes no significant decrease in room temperature bend strength or change in fracture path. With increasing anneal time in a lower oxygen partial pressure environment, the fracture strength decreases only slightly, but the fracture path shifts from the ceramic to the interface.« less

A Novel Anti-Influenza Copper Oxide Containing Respiratory Face Mask

PubMed Central

Borkow, Gadi; Zhou, Steve S.; Page, Tom; Gabbay, Jeffrey

2010-01-01

Background Protective respiratory face masks protect the nose and mouth of the wearer from vapor drops carrying viruses or other infectious pathogens. However, incorrect use and disposal may actually increase the risk of pathogen transmission, rather than reduce it, especially when masks are used by non-professionals such as the lay public. Copper oxide displays potent antiviral properties. A platform technology has been developed that permanently introduces copper oxide into polymeric materials, conferring them with potent biocidal properties. Methodology/Principal Findings We demonstrate that impregnation of copper oxide into respiratory protective face masks endows them with potent biocidal properties in addition to their inherent filtration properties. Both control and copper oxide impregnated masks filtered above 99.85% of aerosolized viruses when challenged with 5.66±0.51 and 6.17±0.37 log10TCID50 of human influenza A virus (H1N1) and avian influenza virus (H9N2), respectively, under simulated breathing conditions (28.3 L/min). Importantly, no infectious human influenza A viral titers were recovered from the copper oxide containing masks within 30 minutes (≤0.88 log10TCID50), while 4.67±1.35 log10TCID50 were recovered from the control masks. Similarly, the infectious avian influenza titers recovered from the copper oxide containing masks were ≤0.97±0.01 log10TCID50 and from the control masks 5.03±0.54 log10TCID50. The copper oxide containing masks successfully passed Bacterial Filtration Efficacy, Differential Pressure, Latex Particle Challenge, and Resistance to Penetration by Synthetic Blood tests designed to test the filtration properties of face masks in accordance with the European EN 14683:2005 and NIOSH N95 standards. Conclusions/Significance Impregnation of copper oxide into respiratory protective face masks endows them with potent anti-influenza biocidal properties without altering their physical barrier properties. The use of biocidal masks

A natural macroalgae consortium for biosorption of copper from aqueous solution: Optimization, modeling and design studies.

PubMed

Deniz, Fatih; Ersanli, Elif Tezel

2018-03-21

In this study, the capacity of a natural macroalgae consortium consisting of Chaetomorpha sp., Polysiphonia sp., Ulva sp. and Cystoseira sp. species for the removal of copper ions from aqueous environment was investigated at different operating conditions, such as solution pH, copper ion concentration and contact time. These environmental parameters affecting the biosorption process were optimized on the basis of batch experiments. The experimentally obtained data for the biosorption of copper ions onto the macroalgae-based biosorbent were modeled using the isotherm models of Freundlich, Langmuir, Sips and Dubinin-Radushkevich and the kinetic models of pseudo-first-order, pseudo-second-order, Elovich and Weber and Morris. The pseudo-first-order and Sips equations were the most suitable models to describe the copper biosorption from aqueous solution. The thermodynamic data revealed the feasibility, spontaneity and physical nature of biosorption process. Based on the data of Sips isotherm model, the biosorption capacity of biosorbent for copper ions was calculated as 105.370 mg g -1 under the optimum operating conditions. A single-stage batch biosorption system was developed to predict the real-scale-based copper removal performance of biosorbent. The results of this investigation showed the potential utility of macroalgae consortium for the biosorption of copper ions from aqueous medium.

49 CFR 192.279 - Copper pipe.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false Copper pipe. 192.279 Section 192.279 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... Copper pipe. Copper pipe may not be threaded except that copper pipe used for joining screw fittings or...

Molecular Mediators Governing Iron-Copper Interactions

PubMed Central

Gulec, Sukru; Collins, James F.

2015-01-01

Given their similar physiochemical properties, it is a logical postulate that iron and copper metabolism are intertwined. Indeed, iron-copper interactions were first documented over a century ago, but the homeostatic effects of one on the other has not been elucidated at a molecular level to date. Recent experimental work has, however, begun to provide mechanistic insight into how copper influences iron metabolism. During iron deficiency, elevated copper levels are observed in the intestinal mucosa, liver, and blood. Copper accumulation and/or redistribution within enterocytes may influence iron transport, and high hepatic copper may enhance biosynthesis of a circulating ferroxidase, which potentiates iron release from stores. Moreover, emerging evidence has documented direct effects of copper on the expression and activity of the iron-regulatory hormone hepcidin. This review summarizes current experimental work in this field, with a focus on molecular aspects of iron-copper interplay and how these interactions relate to various disease states. PMID:24995690

Copper Regulates Cyclic AMP-Dependent Lipolysis

PubMed Central

Krishnamoorthy, Lakshmi; Cotruvo, Joseph A.; Chan, Jefferson; Kaluarachchi, Harini; Muchenditsi, Abigael; Pendyala, Venkata S.; Jia, Shang; Aron, Allegra T.; Ackerman, Cheri M.; Vander Wal, Mark N.; Guan, Timothy; Smaga, Lukas P.; Farhi, Samouil L.; New, Elizabeth J.; Lutsenko, Svetlana; Chang, Christopher J.

2016-01-01

Cell signaling relies extensively on dynamic pools of redox-inactive metal ions such as sodium, potassium, calcium, and zinc, but their redox-active transition metal counterparts such as copper and iron have been studied primarily as static enzyme cofactors. Here we report that copper is an endogenous regulator of lipolysis, the breakdown of fat, which is an essential process in maintaining the body's weight and energy stores. Utilizing a murine model of genetic copper misregulation, in combination with pharmacological alterations in copper status and imaging studies in a 3T3-L1 white adipocyte model, we demonstrate that copper regulates lipolysis at the level of the second messenger, cyclic AMP (cAMP), by altering the activity of the cAMP-degrading phosphodiesterase PDE3B. Biochemical studies of the copper-PDE3B interaction establish copper-dependent inhibition of enzyme activity and identify a key conserved cysteine residue within a PDE3-specific loop that is essential for the observed copper-dependent lipolytic phenotype. PMID:27272565

[Newly leaching method of copper from waste print circuit board using hydrochloric acid/n-butylamine/copper sulfate].

PubMed

Wang, Hong-Yan; Cui, Zhao-Jie; Yao, Ya-Wei

2010-12-01

A newly leaching method of copper from waste print circuit board was established by using hydrochloric acid-n-butylamine-copper sulfate mixed solution. The conditions of leaching were optimized by changing the hydrochloric acid, n-butylamine, copper sulfate,temperature and other conditions using copper as target mimics. The results indicated that copper could be leached completely after 8 h at 50 degrees C, hydrochloric acid concentration of 1.75 mol/L, n-butylamine concentration of 0.25 mol/L, and copper sulfate mass of 0.96 g. Under the conditions, copper leaching rates in waste print circuit board samples was up to 95.31% after 9 h. It has many advantages such as better effects, low cost, mild reaction conditions, leaching solution recycling.

Preparation Of Copper Indium Gallium Diselenide Films For Solar Cells

DOEpatents

Bhattacharya, Raghu N.; Contreras, Miguel A.; Keane, James; Tennant, Andrew L. , Tuttle, John R.; Ramanathan, Kannan; Noufi, Rommel

1998-08-08

High quality thin films of copper-indium-gallium-diselenide useful in the production of solar cells are prepared by electrodepositing at least one of the constituent metals onto a glass/Mo substrate, followed by physical vapor deposition of copper and selenium or indium and selenium to adjust the final stoichiometry of the thin film to approximately Cu(In,Ga)Se.sub.2. Using an AC voltage of 1-100 KHz in combination with a DC voltage for electrodeposition improves the morphology and growth rate of the deposited thin film. An electrodeposition solution comprising at least in part an organic solvent may be used in conjunction with an increased cathodic potential to increase the gallium content of the electrodeposited thin film.

Process Of Bonding Copper And Tungsten

DOEpatents

Slattery, Kevin T.; Driemeyer, Daniel E.

1999-11-23

Process for bonding a copper substrate to a tungsten substrate by providing a thin metallic adhesion promoting film bonded to a tungsten substrate and a functionally graded material (FGM) interlayer bonding the thin metallic adhesion promoting film to the copper substrate. The FGM interlayer is formed by thermal plasma spraying mixtures of copper powder and tungsten powder in a varied blending ratio such that the blending ratio of the copper powder and the tungsten powder that is fed to a plasma torch is intermittently adjusted to provide progressively higher copper content/tungsten content, by volume, ratio values in the interlayer in a lineal direction extending from the tungsten substrate towards the copper substrate. The resulting copper to tungsten joint well accommodates the difference in the coefficient of thermal expansion of the materials.

Process Of Bonding Copper And Tungsten

DOEpatents

Slattery, Kevin T.; Driemeyer, Daniel E.; Davis, John W.

2000-07-18

Process for bonding a copper substrate to a tungsten substrate by providing a thin metallic adhesion promoting film bonded to a tungsten substrate and a functionally graded material (FGM) interlayer bonding the thin metallic adhesion promoting film to the copper substrate. The FGM interlayer is formed by sintering a stack of individual copper and tungsten powder blend layers having progressively higher copper content/tungsten content, by volume, ratio values in successive powder blend layers in a lineal direction extending from the tungsten substrate towards the copper substrate. The resulting copper to tungsten joint well accommodates the difference in the coefficient of thermal expansion of the materials.

Copper-zinc superoxide dismutase is activated through a sulfenic acid intermediate at a copper ion entry site.

PubMed

Fetherolf, Morgan M; Boyd, Stefanie D; Taylor, Alexander B; Kim, Hee Jong; Wohlschlegel, James A; Blackburn, Ninian J; Hart, P John; Winge, Dennis R; Winkler, Duane D

2017-07-21

Metallochaperones are a diverse family of trafficking molecules that provide metal ions to protein targets for use as cofactors. The copper chaperone for superoxide dismutase (Ccs1) activates immature copper-zinc superoxide dismutase (Sod1) by delivering copper and facilitating the oxidation of the Sod1 intramolecular disulfide bond. Here, we present structural, spectroscopic, and cell-based data supporting a novel copper-induced mechanism for Sod1 activation. Ccs1 binding exposes an electropositive cavity and proposed "entry site" for copper ion delivery on immature Sod1. Copper-mediated sulfenylation leads to a sulfenic acid intermediate that eventually resolves to form the Sod1 disulfide bond with concomitant release of copper into the Sod1 active site. Sod1 is the predominant disulfide bond-requiring enzyme in the cytoplasm, and this copper-induced mechanism of disulfide bond formation obviates the need for a thiol/disulfide oxidoreductase in that compartment. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Research and development of plasma sprayed tungsten coating on graphite and copper substrates

NASA Astrophysics Data System (ADS)

Liu, Xiang; Zhang, Fu; Tao, Shunyan; Cao, Yunzhen; Xu, Zengyu; Liu, Yong; Noda, N.

2007-06-01

Vacuum plasma sprayed tungsten coating on graphite and copper substrates has been prepared. VPS-W coated graphite has multilayered silicon and tungsten interface pre-deposited by physical vapor deposition (PVD) and VPS-W coated copper has graded transition interlayer. VPS-W coating was characterized, and then the high heat flux properties of the coating were examined. Experimental results indicated that both VPS-W coated graphite and VPS-W coated copper could endure 1000 cycles without visible failure under a heat flux of approximately 5 MW/m2 absorbed power density and 5 s pulse duration. A comparison between the present VPS-W coated graphite and VPS-W coated carbon fiber composite (CX-2002U) with Re interface made by Plansee Aktiengesllshaft was carried out. Results show that both Re and Si are suitable as intermediate layer for tungsten coating on carbon substrates.

Interfacial thermal resistance and thermal rectification in carbon nanotube film-copper systems.

PubMed

Duan, Zheng; Liu, Danyang; Zhang, Guang; Li, Qingwei; Liu, Changhong; Fan, Shoushan

2017-03-02

Thermal rectification occurring at interfaces is an important research area, which contains deep fundamental physics and has extensive application prospects. In general, the measurement of interfacial thermal rectification is based on measuring interfacial thermal resistance (ITR). However, ITRs measured via conventional methods cannot avoid extra thermal resistance asymmetry due to the contact between the sample and the thermometer. In this study, we employed a non-contact infrared thermal imager to monitor the temperature of super-aligned carbon nanotube (CNT) films and obtain the ITRs between the CNT films and copper. The ITRs along the CNT-copper direction and the reverse direction are in the ranges of 2.2-3.6 cm 2 K W -1 and 9.6-11.9 cm 2 K W -1 , respectively. The obvious difference in the ITRs of the two directions shows a significant thermal rectification effect, and the rectifying coefficient ranges between 0.57 and 0.68. The remarkable rectification factor is extremely promising for the manufacture of thermal transistors with a copper/CNT/copper structure and further thermal logic devices. Moreover, our method could be extended to other 2-dimensional materials, such as graphene and MoS 2 , for further explorations.

High adherence copper plating process

DOEpatents

Nignardot, H.

1993-09-21

A process is described for applying copper to a substrate of aluminum or steel by electrodeposition and for preparing the surface of an aluminum or steel substrate for the electrodeposition of copper. Practice of the invention provides good adhesion of the copper layer to either substrate.

Techniques for the Analysis of Expendable Bathythermograph (XBT) Data with Applications to the South-Western Pacific Ocean.

DTIC Science & Technology

1981-09-01

F6 .O...4X,F5.2,5X,F5 .2,SX,F6.3,4X,F8.6,2X,F8.6,2X,F7.3, Z5X,F5.1,4X,F5.2,3X,F7.2,4X, F6 .3, 4X , F6 .4) 340 FORMAT( F6 .O,F5.2,F5.2,F6.3,F8.6,F8.6,F7.3, ZF5. 1...New York NY� 3 Data Courier Inc, Louisville Ky 40202 4 In Malaysia The Director, Defence Research Centre, Malaysia 5 In Australia Chief

Colloidal and electrochemical aspects of copper-CMP

NASA Astrophysics Data System (ADS)

Sun, Yuxia

Copper based interconnects with low dielectric constant layers are currently used to increase interconnect densities and reduce interconnect time delays in integrated circuits. The technology used to develop copper interconnects involves Chemical Mechanical Planarization (CMP) of copper films deposited on low-k layers (silica or silica based films), which is carried out using slurries containing abrasive particles. One issue using such a structure is copper contamination over dielectric layers (SiO2 film), if not reduced, this contamination will cause current leakage. In this study, the conditions conducive to copper contamination onto SiO2 films during Cu-CMP process were studied, and a post-CMP cleaning technique was discussed based on experimental results. It was found that the adsorption of copper onto a silica surface is kinetically fast (<0.5 minute). The amount of copper absorbed is pH and concentration dependent and affected by presence of H2O2, complexing agents, and copper corrosion inhibitor Benzotrazole. Based on de-sorption results, DI water alone was unable to reduce adsorbed copper to an acceptable level, especially for adsorption that takes place at a higher pH condition. The addition of complex agent, citric acid, proved effective in suppressing copper adsorption onto oxide silica during polishing or post-CMP cleaning by forming stable copper-CA complexes. Surface Complexation Modeling was used to simulate copper adsorption isotherms and predict the copper contamination levels on SiO2 surfaces. Another issue with the application of copper CMP is its environmental impact. CMP is a costly process due to its huge consumption of pure water and slurry. Additionally, Cu-CMP processing generates a waste stream containing certain amounts of copper and abrasive slurry particles. In this study, the separation technique electrocoagulation was investigated to remove both copper and abrasive slurry particles simultaneously. For effluent containing ˜40 ppm

Reduction of the "burst release" of copper ions from copper-based intrauterine devices by organic inhibitors.

PubMed

Alvarez, Florencia; Schilardi, Patricia L; de Mele, Monica Fernández Lorenzo

2012-01-01

The copper intrauterine device is a contraceptive method that is based on the release of copper ions from a copper wire. Immediately after insertion, the dissolution of copper in the uterine fluid is markedly higher ("burst release") than that necessary for contraception action, leading to a variety of harmful effects. Pretreatments with organic compounds [thiourea (TU) and purine (PU), 10(-4)-10(-2) M concentration range, 1- and 3-h immersion times] were tested. The dissolution of copper with and without pretreatments in TU and PU solutions was analyzed by conventional electrochemical techniques and surface analysis. Pretreatments in PU solutions reduced the initial corrosion rate of copper in simulated uterine solutions, with inhibitory efficiencies that depend on the PU concentration and on the immersion time assayed. Inhibitory efficiency values higher than 98% for pretreatments with ≥10(-3) M PU were found. Conversely, after TU pretreatments, a high copper release was measured. It was concluded that 10(-3) M PU pretreatment is a promising strategy able to reduce the "burst release" of copper and to ensure contraceptive action. Copyright © 2012 Elsevier Inc. All rights reserved.

21 CFR 73.2125 - Potassium sodium copper chlorophyllin (chlorophyllin-copper complex).

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Potassium sodium copper chlorophyllin (chlorophyllin-copper complex). 73.2125 Section 73.2125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics...

21 CFR 73.2125 - Potassium sodium copper chlorophyllin (chlorophyllin-copper complex).

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Potassium sodium copper chlorophyllin (chlorophyllin-copper complex). 73.2125 Section 73.2125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics...

Microstructural characterization of ultra thin copper interconnects

NASA Astrophysics Data System (ADS)

Yang, Hee-Dong

The present study investigates the defects related to reliability issues, such as physical failures developed during processing and end use. In the first part of this study, kinetic analysis using the Johnson-Mehl-Avrami (JMA) model demonstrates that a self-annealing mechanism in electroplated Cu films depends on the film properties, such as thickness and the amount of crystal defects in an as-deposited state. In order to obtain the evidence of such defects, the microstructural characterization of defects in ultra thin copper interconnects using transmission electron microscopy (TEM) is presented. Examination of the defects using TEM reveals that voids filled with gas form as a lens shape along the {110} habit planes of the copper matrix. In the second part of this study, methodology and results of an electro-thermal-fatigue (ETF) testing, designed for early detection of process defects, are presented. Such ETF testing combines high-density current electrical stressing and thermal cycling to accelerate the evolution of defects in Cu interconnects. In ETF testing, the evolution of defects provides the nucleation sites for voids which open or close during thermal cycling. Then, the accumulation of voids creates the change in resistance when they reach a critical size. As a result of voids evolution, the high current density and high joule heating create a transient resistance increase. ETF testing reveals two failure modes, and the mode-I failure has the importance in detecting defects. The number of cycles to failure in ETF testing decreases with higher current density, but the rate of thermal cycling has no effect. Results from this investigation suggest that impurities in the copper electrodeposition process must be carefully controlled to achieve reliable ultra thin copper interconnects.

Arizona Copper

NASA Image and Video Library

2014-03-19

Arizona produces 60% of the total copper mined in the US; in 2007, 750,000 tons of copper came out of the state. One of the major mining districts is located about 30 km south of Tucson. Starting around 1950, open-pit mining replaced underground operations, and the ASARCO-Mission complex, Twin Buttes, and Sierrita mines became large open pit operations. Accompanying copper mineralization, silver, molybdenum, zinc, lead and gold are extracted. In addition to the pits themselves, enormous leach ponds and tailings piles surround the pits. The image was acquired May 31, 2012, covers an area of 22 by 28 km, and is located at 31.9 degrees north, 111 degrees west. With its 14 spectral bands from the visible to the thermal infrared wavelength region and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched Dec. 18, 1999, on Terra. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate, Washington, D.C. More information about ASTER is available at asterweb.jpl.nasa.gov/ Credit: NASA

Characteristics and antimicrobial activity of copper-based materials

NASA Astrophysics Data System (ADS)

Li, Bowen

In this study, copper vermiculite was synthesized, and the characteristics, antimicrobial effects, and chemical stability of copper vermiculite were investigated. Two types of copper vermiculite materials, micron-sized copper vermiculite (MCV) and exfoliated copper vermiculite (MECV), are selected for this research. Since most of the functional fillers used in industry products, such as plastics, paints, rubbers, papers, and textiles prefer micron-scaled particles, micron-sized copper vermiculite was prepared by jet-milling vermiculite. Meanwhile, since the exfoliated vermiculite has very unique properties, such as high porosity, specific surface area, high aspect ratio of laminates, and low density, and has been extensively utilized as a functional additives, exfoliated copper vermiculite also was synthesized and investigated. The antibacterial efficiency of copper vermiculite was qualitatively evaluated by the diffusion methods (both liquid diffusion and solid diffusion) against the most common pathogenic species: Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Klebsiella pneumoniae (K. pneumoniae). The result showed that the release velocity of copper from copper vermiculite is very slow. However, copper vermiculite clearly has excellent antibacterial efficiency to S. aureus, K. pneumoniae and E. coli. The strongest antibacterial ability of copper vermiculite is its action on S. aureus. The antibacterial efficiency of copper vermiculite was also quantitatively evaluated by determining the reduction rate (death rate) of E. coli versus various levels of copper vermiculite. 10 ppm of copper vermiculite in solution is sufficient to reduce the cell population of E. coli, while the untreated vermiculite had no antibacterial activity. The slow release of copper revealed that the antimicrobial effect of copper vermiculite was due to the strong interactions between copper ions and bacteria cells. Exfoliated copper vermiculite has even stronger

Accumulation and hyperaccumulation of copper in plants

NASA Astrophysics Data System (ADS)

Adam, V.; Trnkova, L.; Huska, D.; Babula, P.; Kizek, R.

2009-04-01

Copper is natural component of our environment. Flow of copper(II) ions in the environment depends on solubility of compounds containing this metal. Mobile ion coming from soil and rocks due to volcanic activity, rains and others are then distributed to water. Bio-availability of copper is substantially lower than its concentration in the aquatic environment. Copper present in the water reacts with other compounds and creates a complex, not available for organisms. The availability of copper varies depending on the environment, but moving around within the range from 5 to 25 % of total copper. Thus copper is stored in the sediments and the rest is transported to the seas and oceans. It is common knowledge that copper is essential element for most living organisms. For this reason this element is actively accumulated in the tissues. The total quantity of copper in soil ranges from 2 to 250 mg / kg, the average concentration is 30 mg / kg. Certain activities related to agriculture (the use of fungicides), possibly with the metallurgical industry and mining, tend to increase the total quantity of copper in the soil. This amount of copper in the soil is a problem particularly for agricultural production of food. The lack of copper causes a decrease in revenue and reduction in quality of production. In Europe, shows the low level of copper in total 18 million hectares of farmland. To remedy this adverse situation is the increasing use of copper fertilizers in agricultural soils. It is known that copper compounds are used in plant protection against various illnesses and pests. Mining of minerals is for the development of human society a key economic activity. An important site where the copper is mined in the Slovakia is nearby Smolníka. Due to long time mining in his area (more than 700 years) there are places with extremely high concentrations of various metals including copper. Besides copper, there are also detected iron, zinc and arsenic. Various plant species

21 CFR 73.1125 - Potassium sodium copper chloropyhllin (chlorophyllin-copper complex).

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Potassium sodium copper chloropyhllin (chlorophyllin-copper complex). 73.1125 Section 73.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73...

21 CFR 73.1125 - Potassium sodium copper chloropyhllin (chlorophyllin-copper complex).

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Potassium sodium copper chloropyhllin (chlorophyllin-copper complex). 73.1125 Section 73.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73...

21 CFR 73.1125 - Potassium sodium copper chloropyhllin (chlorophyllin-copper complex).

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Potassium sodium copper chloropyhllin (chlorophyllin-copper complex). 73.1125 Section 73.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73...

21 CFR 73.1125 - Potassium sodium copper chloropyhllin (chlorophyllin-copper complex).

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Potassium sodium copper chloropyhllin (chlorophyllin-copper complex). 73.1125 Section 73.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73...

Identifying the Molecular Origin of Global Warming

NASA Technical Reports Server (NTRS)

Bera, Partha P.; Francisco, Joseph S.; Lee, Timothy J.

2009-01-01

We have investigated the physical characteristics of greenhouse gases (GHGs) to assess which properties are most important in determining the efficiency of a GHG. Chlorofluorcarbons (CFCs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), nitrogen fluorides, and various other known atmospheric trace molecules have been included in this study. Compounds containing the halogens F or Cl have in common very polar X-F or X-Cl bonds, particularly the X-F bonds. It is shown that as more F atoms bond to the same central atom, the bond dipoles become larger as a result of the central atom becoming more positive. This leads to a linear increase in the total or integrated XF bond dipole derivatives for the molecule, which leads to a non-linear (quadratic) increase in infrared (IR) intensity. Moreover, virtually all of the X-F bond stretches occur in the atmospheric IR window as opposed to X-H stretches, which do not occur in the atmospheric window. It is concluded that molecules possessing several F atoms will always have a large radiative forcing parameter in the calculation of their global warming potential. Some of the implications for global warming and climate change are discussed.

A Study of the Optimal Model of the Flotation Kinetics of Copper Slag from Copper Mine BOR

NASA Astrophysics Data System (ADS)

Stanojlović, Rodoljub D.; Sokolović, Jovica M.

2014-10-01

In this study the effect of mixtures of copper slag and flotation tailings from copper mine Bor, Serbia on the flotation results of copper recovery and flotation kinetics parameters in a batch flotation cell has been investigated. By simultaneous adding old flotation tailings in the ball mill at the rate of 9%, it is possible to increase copper recovery for about 20%. These results are compared with obtained copper recovery of pure copper slag. The results of batch flotation test were fitted by MatLab software for modeling the first-order flotation kinetics in order to determine kinetics parameters and define an optimal model of the flotation kinetics. Six kinetic models are tested on the batch flotation copper recovery against flotation time. All models showed good correlation, however the modified Kelsall model provided the best fit.

Unraveling the Amycolatopsis tucumanensis copper-resistome.

PubMed

Dávila Costa, José Sebastián; Kothe, Erika; Abate, Carlos Mauricio; Amoroso, María Julia

2012-10-01

Heavy metal pollution is widespread causing serious ecological problems in many parts of the world; especially in developing countries where a budget for remediation technology is not affordable. Therefore, screening for microbes with high accumulation capacities and studying their stable resistance characteristics is advisable to define cost-effective any remediation strategies. Herein, the copper-resistome of the novel copper-resistant strain Amycolatopsis tucumanensis was studied using several approaches. Two dimensional gel electrophoresis revealed that proteins of the central metabolism, energy production, transcriptional regulators, two-component system, antioxidants and protective metabolites increased their abundance upon copper-stress conditions. Transcriptome analysis revealed that in presence of copper, superoxide dismutase, alkyl hydroperoxide reductase and mycothiol reductase genes were markedly induced in expression. The oxidative damage of protein and lipid from A. tucumanensis was negligible compared with that observed in the copper-sensitive strain Amycolatopsis eurytherma. Thus, we provide evidence that A. tucumamensis shows a high adaptation towards copper, the sum of which is proposed as the copper-resistome. This adaptation allows the strain to accumulate copper and survive this stress; besides, it constitutes the first report in which the copper-resistome of a strain of the genus Amycolatopsis with bioremediation potential has been evaluated.

Copper-2 Ingestion, Plus Increased Meat Eating Leading to Increased Copper Absorption, Are Major Factors Behind the Current Epidemic of Alzheimer's Disease.

PubMed

Brewer, George J

2015-12-02

It has become clear that copper toxicity is playing a major role in Alzheimer's disease; but why is the brain copper toxicity with cognition loss in Alzheimer's disease so much different clinically than brain copper toxicity in Wilson's disease, which results in a movement disorder? Furthermore, why is the inorganic copper of supplement pills and in drinking water so much more damaging to cognition than the organic copper in food? A recent paper, which shows that almost all food copper is copper-1, that is the copper-2 of foods reverts to the reduced copper-1 form at death or harvest, gives new insight into these questions. The body has an intestinal transport system for copper-1, Ctr1, which channels copper-1 through the liver and into safe channels. Ctr1 cannot absorb copper-2, and some copper-2 bypasses the liver, ends up in the blood quickly, and is toxic to cognition. Humans evolved to handle copper-1 safely, but not copper-2. Alzheimer's is at least in part, a copper-2 toxicity disease, while Wilson's is a general copper overload disease. In this review, we will show that the epidemiology of the Alzheimer's epidemic occurring in developed, but not undeveloped countries, fits with the epidemiology of exposure to copper-2 ingestion leached from copper plumbing and from copper supplement pill ingestion. Increased meat eating in developed countries is also a factor, because it increases copper absorption, and thus over all copper exposure.

Copper toxicity in ruminant animals

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

Oehme, F.W.

This discussion includes clinical and post mortem features, metabolism of both normal and toxic quantities of copper, effect of copper upon the tissues, and control treatment and prevention of copper toxicity. These effects are discussed in regard to ruminants. Specific emphasis is placed on metabolism and biochemistry. 33 references, 3 figures.

Metallic copper as an antimicrobial surface.

PubMed

Grass, Gregor; Rensing, Christopher; Solioz, Marc

2011-03-01

Bacteria, yeasts, and viruses are rapidly killed on metallic copper surfaces, and the term "contact killing" has been coined for this process. While the phenomenon was already known in ancient times, it is currently receiving renewed attention. This is due to the potential use of copper as an antibacterial material in health care settings. Contact killing was observed to take place at a rate of at least 7 to 8 logs per hour, and no live microorganisms were generally recovered from copper surfaces after prolonged incubation. The antimicrobial activity of copper and copper alloys is now well established, and copper has recently been registered at the U.S. Environmental Protection Agency as the first solid antimicrobial material. In several clinical studies, copper has been evaluated for use on touch surfaces, such as door handles, bathroom fixtures, or bed rails, in attempts to curb nosocomial infections. In connection to these new applications of copper, it is important to understand the mechanism of contact killing since it may bear on central issues, such as the possibility of the emergence and spread of resistant organisms, cleaning procedures, and questions of material and object engineering. Recent work has shed light on mechanistic aspects of contact killing. These findings will be reviewed here and juxtaposed with the toxicity mechanisms of ionic copper. The merit of copper as a hygienic material in hospitals and related settings will also be discussed.

Copper transport and regulation in Schizosaccharomyces pombe.

PubMed

Beaudoin, Jude; Ekici, Seda; Daldal, Fevzi; Ait-Mohand, Samia; Guérin, Brigitte; Labbé, Simon

2013-12-01

The fission yeast Schizosaccharomyces pombe has been successfully used as a model to gain fundamental knowledge in understanding how eukaryotic cells acquire copper during vegetative growth. These studies have revealed the existence of a heteromeric Ctr4-Ctr5 plasma membrane complex that mediates uptake of copper within the cells. Furthermore, additional studies have led to the identification of one of the first vacuolar copper transporters, Ctr6, as well as the copper-responsive Cuf1 transcription factor. Recent investigations have extended the use of S. pombe to elucidate new roles for copper metabolism in meiotic differentiation. For example, these studies have led to the discovery of Mfc1, which turned out to be the first example of a meiosis-specific copper transporter. Whereas copper-dependent transcriptional regulation of the Ctr family members is under the control of Cuf1 during mitosis or meiosis, meiosis-specific copper transporter Mfc1 is regulated by the recently discovered transactivator Mca1. It is foreseeable that identification of novel meiotic copper-related proteins will serve as stepping stones to unravel fundamental aspects of copper homoeostasis.

Copper-Zinc Superoxide Dismutase: A Unique Biological "Ligand" for Bioinorganic Studies.

ERIC Educational Resources Information Center

Valentine, Joan Selverstone; de Freitas, Duarte Mota

1985-01-01

Discusses superoxide dismutase (SOD) research and the properties of copper, zinc (Cu, Zn)-SOD. Emphasizes the controversy concerning the role of Cu,Zn-SOD and other SOD enzymes as protective agents in reactions involving dioxygen metabolism, and the properties of Cu, Zn-SOD that make it an interesting biological ligand for physical studies of…

The physics of heavy quark distributions in hadrons: Collider tests

NASA Astrophysics Data System (ADS)

Brodsky, S. J.; Bednyakov, V. A.; Lykasov, G. I.; Smiesko, J.; Tokar, S.

2017-03-01

We present a review of the current understanding of the heavy quark distributions in the nucleon and their impact on collider physics. The origin of strange, charm and bottom quark pairs at high light-front (LF) momentum fractions in hadron wavefunction-the "intrinsic" quarks, is reviewed. The determination of heavy-quark parton distribution functions (PDFs) is particularly significant for the analysis of hard processes at LHC energies. We show that a careful study of the inclusive production of open charm and the production of γ / Z / W particles, accompanied by the heavy jets at large transverse momenta can give essential information on the intrinsic heavy quark (IQ) distributions. We also focus on the theoretical predictions concerning other observables which are very sensitive to the intrinsic charm contribution to PDFs including Higgs production at high xF and novel fixed target measurements which can be tested at the LHC.

Quantitative analysis of oxygen content in copper oxide films using ultra microbalance

NASA Astrophysics Data System (ADS)

Shu, Yonghua; Wang, Lianhong; Liu, Chong; Fan, Jing

2014-12-01

Copper oxide films were prepared on quartz substrates through electron beam physical vapor deposition in a vacuum chamber, and the films were observed using X-ray diffraction (XRD) and scanning electron microscope (SEM). The oxygen content of the films were analyzed using an ultra microbalance. Results indicated that when the substrate was heated to 600°C and the oxygen flow rate was 5 sccm, the film was composed of 47% Cu and 53% Cu2O (mass percent), and the oxidation ratio of copper was 25%. After the deposition process at the same condition, i.e. the substrate at temperature of 600°C and blowed by oxygen flowrate of 5 sccm, then in-stu annealed at 600°C in low oxygen pressure of 10 Pa for 30 minutes, the film composition became 22% Cu2O and 78% CuO (mass percent), and the oxidation ratio of copper greatly increased to about 88%.

The future of copper in China--A perspective based on analysis of copper flows and stocks.

PubMed

Zhang, Ling; Cai, Zhijian; Yang, Jiameng; Yuan, Zengwei; Chen, Yan

2015-12-01

This study attempts to speculate on the future of copper metabolism in China based on dynamic substance flow analysis. Based on tremendous growth of copper consumption over the past 63 years, China will depict a substantially increasing trend of copper in-use stocks for the next 30 years. The highest peak will be possibly achieved in 2050, with the maximum ranging between 163 Mt and 171 Mt. After that, total stocks are expected to slowly decline 147-154 Mt by the year 2080. Owing to the increasing demand of in-use stocks, China will continue to have a profound impact on global copper consumption with its high import dependence until around 2020, and the peak demand for imported copper are expected to approach 5.5 Mt/year. Thereafter, old scrap generated by domestic society will occupy an increasingly important role in copper supply. In around 2060, approximately 80% of copper resources could come from domestic recycling of old scrap, implying a major shift from primary production to secondary production. With regard to the effect of lifetime distribution uncertainties in different end-use sectors of copper stocks on the predict results, uncertainty evaluation was performed and found the model was relatively robust to these changes. Copyright © 2015 Elsevier B.V. All rights reserved.

Copper recovery and cyanide oxidation by electrowinning from a spent copper-cyanide electroplating electrolyte.

PubMed

Dutra, A J B; Rocha, G P; Pombo, F R

2008-04-01

Copper-cyanide bleed streams arise from contaminated baths from industrial electroplating processes due to the buildup of impurities during continuous operation. These streams present an elevated concentration of carbonate, cyanide and copper, constituting a heavy hazard, which has to be treated for cyanide destruction and heavy metals removal, according to the local environmental laws. In the Brazilian Mint, bleed streams are treated with sodium hypochlorite, to destroy cyanide and precipitate copper hydroxide, a solid hazardous waste that has to be disposed properly in a landfill or treated for metal recovery. In this paper, a laboratory-scale electrolytic cell was developed to remove the copper from the bleed stream of the electroplating unit of the Brazilian Mint, permitting its reutilization in the plant and decreasing the amount of sludge to waste. Under favorable conditions copper recoveries around 99.9% were achieved, with an energy consumption of about 11 kWh/kg, after a 5-h electrolysis of a bath containing copper and total cyanide concentrations of 26 and 27 g/L, respectively. Additionally, a substantial reduction of the cyanide concentration was also achieved, decreasing the pollution load and final treatment costs.

Selective leaching process for the recovery of copper and zinc oxide from copper-containing dust.

PubMed

Wu, Jun-Yi; Chang, Fang-Chih; Wang, H Paul; Tsai, Ming-Jer; Ko, Chun-Han; Chen, Chih-Cheng

2015-01-01

The purpose of this study was to develop a resource recovery procedure for recovering copper and zinc from dust produced by copper smelting furnaces during the manufacturing of copper-alloy wires. The concentrations of copper in copper-containing dust do not meet the regulation standards defined by the Taiwan Environmental Protection Administration; therefore, such waste is classified as hazardous. In this study, the percentages of zinc and copper in the dust samples were approximately 38.4% and 2.6%, respectively. To reduce environmental damage and recover metal resources for industrial reuse, acid leaching was used to recover metals from these inorganic wastes. In the first stage, 2 N of sulphuric acid was used to leach the dust, with pH values controlled at 2.0-3.0, and a solid-to-liquid ratio of 1:10. The results indicated that zinc extraction efficiency was higher than 95%. A selective acid leaching process was then used to recover the copper content of the residue after filtration. In the second stage, an additional 1 N of sulphuric acid was added to the suspension in the selective leaching process, and the pH value was controlled at 1.5-2.0. The reagent sodium hydroxide (2 N) was used as leachate at a pH greater than 7. A zinc hydroxide compound formed during the process and was recovered after drying. The yields for zinc and copper were 86.9-93.5% and 97.0-98.9%, respectively.

Copper: a metal for the ages

USGS Publications Warehouse

Doebrich, Jeff

2009-01-01

Copper was one of the first metals ever extracted and used by humans, and it has made vital contributions to sustaining and improving society since the dawn of civilization. Copper was first used in coins and ornaments starting about 8000 B.C., and at about 5500 B.C., copper tools helped civilization emerge from the Stone Age. The discovery that copper alloyed with tin produces bronze marked the beginning of the Bronze Age at about 3000 B.C. Copper is easily stretched, molded, and shaped; is resistant to corrosion; and conducts heat and electricity efficiently. As a result, copper was important to early humans and continues to be a material of choice for a variety of domestic, industrial, and high-technology applications today.

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.

Aquatic Life Criteria - Copper

EPA Pesticide Factsheets

Documents pertain to Aquatic Life Ambient Water Quality criteria for Copper (2007 Freshwater, 2016 Estuarine/marine). These documents contain the safe levels of Copper in water that should protect to the majority of species.

A promising structure for fabricating high strength and high electrical conductivity copper alloys

PubMed Central

Li, Rengeng; Kang, Huijun; Chen, Zongning; Fan, Guohua; Zou, Cunlei; Wang, Wei; Zhang, Shaojian; Lu, Yiping; Jie, Jinchuan; Cao, Zhiqiang; Li, Tingju; Wang, Tongmin

2016-01-01

To address the trade-off between strength and electrical conductivity, we propose a strategy: introducing precipitated particles into a structure composed of deformation twins. A Cu-0.3%Zr alloy was designed to verify our strategy. Zirconium was dissolved into a copper matrix by solution treatment prior to cryorolling and precipitated in the form of Cu5Zr from copper matrix via a subsequent aging treatment. The microstructure evolutions of the processed samples were investigated by transmission electron microscopy and X-ray diffraction analysis, and the mechanical and physical behaviours were evaluated through tensile and electrical conductivity tests. The results demonstrated that superior tensile strength (602.04 MPa) and electrical conductivity (81.4% IACS) was achieved. This strategy provides a new route for balancing the strength and electrical conductivity of copper alloys, which can be developed for large-scale industrial application. PMID:26856764

Rapid Copper Acquisition by Developing Murine Mesothelioma: Decreasing Bioavailable Copper Slows Tumor Growth, Normalizes Vessels and Promotes T Cell Infiltration

PubMed Central

Crowe, Andrew; Jackaman, Connie; Beddoes, Katie M.; Ricciardo, Belinda; Nelson, Delia J.

2013-01-01

Copper, an essential trace element acquired through nutrition, is an important co-factor for pro-angiogenic factors including vascular endothelial growth factor (VEGF). Decreasing bioavailable copper has been used as an anti-angiogenic and anti-cancer strategy with promising results. However, the role of copper and its potential as a therapy in mesothelioma is not yet well understood. Therefore, we monitored copper levels in progressing murine mesothelioma tumors and analyzed the effects of lowering bioavailable copper. Copper levels in tumors and organs were assayed using atomic absorption spectrophotometry. Mesothelioma tumors rapidly sequestered copper at early stages of development, the copper was then dispersed throughout growing tumor tissues. These data imply that copper uptake may play an important role in early tumor development. Lowering bioavailable copper using the copper chelators, penicillamine, trientine or tetrathiomolybdate, slowed in vivo mesothelioma growth but did not provide any cures similar to using cisplatin chemotherapy or anti-VEGF receptor antibody therapy. The impact of copper lowering on tumor blood vessels and tumor infiltrating T cells was measured using flow cytometry and confocal microscopy. Copper lowering was associated with reduced tumor vessel diameter, reduced endothelial cell proliferation (reduced Ki67 expression) and lower surface ICAM/CD54 expression implying reduced endothelial cell activation, in a process similar to endothelial normalization. Copper lowering was also associated with a CD4+ T cell infiltrate. In conclusion, these data suggest copper lowering is a potentially useful anti-mesothelioma treatment strategy that slows tumor growth to provide a window of opportunity for inclusion of other treatment modalities to improve patient outcomes. PMID:24013775

Copper transport and regulation in Schizosaccharomyces pombe

PubMed Central

Beaudoin, Jude; Ekici, Seda; Daldal, Fevzi; Ait-Mohand, Samia; Guérin, Brigitte; Labbé, Simon

2016-01-01

The fission yeast Schizosaccharomyces pombe has been successfully used as a model to gain fundamental knowledge in understanding how eukaryotic cells acquire copper during vegetative growth. These studies have revealed the existence of a heteromeric Ctr4–Ctr5 plasma membrane complex that mediates uptake of copper within the cells. Furthermore, additional studies have led to the identification of one of the first vacuolar copper transporters, Ctr6, as well as the copper-responsive Cuf1 transcription factor. Recent investigations have extended the use of S. pombe to elucidate new roles for copper metabolism in meiotic differentiation. For example, these studies have led to the discovery of Mfc1, which turned out to be the first example of a meiosis-specific copper transporter. Whereas copper-dependent transcriptional regulation of the Ctr family members is under the control of Cuf1 during mitosis or meiosis, meiosis-specific copper transporter Mfc1 is regulated by the recently discovered transactivator Mca1. It is foreseeable that identification of novel meiotic copper-related proteins will serve as stepping stones to unravel fundamental aspects of copper homoeostasis. PMID:24256274

Urinary Copper Elevation in a Mouse Model of Wilson's Disease Is a Regulated Process to Specifically Decrease the Hepatic Copper Load

PubMed Central

Gray, Lawrence W.; Peng, Fangyu; Molloy, Shannon A.; Pendyala, Venkata S.; Muchenditsi, Abigael; Muzik, Otto; Lee, Jaekwon; Kaplan, Jack H.; Lutsenko, Svetlana

2012-01-01

Body copper homeostasis is regulated by the liver, which removes excess copper via bile. In Wilson's disease (WD), this function is disrupted due to inactivation of the copper transporter ATP7B resulting in hepatic copper overload. High urinary copper is a diagnostic feature of WD linked to liver malfunction; the mechanism behind urinary copper elevation is not fully understood. Using Positron Emission Tomography-Computed Tomography (PET-CT) imaging of live Atp7b−/− mice at different stages of disease, a longitudinal metal analysis, and characterization of copper-binding molecules, we show that urinary copper elevation is a specific regulatory process mediated by distinct molecules. PET-CT and atomic absorption spectroscopy directly demonstrate an age-dependent decrease in the capacity of Atp7b−/− livers to accumulate copper, concomitant with an increase in urinary copper. This reciprocal relationship is specific for copper, indicating that cell necrosis is not the primary cause for the initial phase of metal elevation in the urine. Instead, the urinary copper increase is associated with the down-regulation of the copper-transporter Ctr1 in the liver and appearance of a 2 kDa Small Copper Carrier, SCC, in the urine. SCC is also elevated in the urine of the liver-specific Ctr1 −/− knockouts, which have normal ATP7B function, suggesting that SCC is a normal metabolite carrying copper in the serum. In agreement with this hypothesis, partially purified SCC-Cu competes with free copper for uptake by Ctr1. Thus, hepatic down-regulation of Ctr1 allows switching to an SCC-mediated removal of copper via kidney when liver function is impaired. These results demonstrate that the body regulates copper export through more than one mechanism; better understanding of urinary copper excretion may contribute to an improved diagnosis and monitoring of WD. PMID:22802922

Copper localization, elemental content, and thallus colour in the copper hyperaccumulator lichen Lecanora sierrae from California

USGS Publications Warehouse

Purvis, O.W.; Bennett, J.P.; Spratt, J.

2011-01-01

An unusual dark blue-green lichen, Lecanora sierrae, was discovered over 30 years ago by Czehura near copper mines in the Lights Creek District, Plumas County, Northern California. Using atomic absorption spectroscopy, Czehura found that dark green lichen samples from Warren Canyon contained 4% Cu in ash and suggested that its colour was due to copper accumulation in the cortex. The present study addressed the hypothesis that the green colour in similar material we sampled from Warren Canyon in 2008, is caused by copper localization in the thallus. Optical microscopy and electron microprobe analysis of specimens of L. sierrae confirmed that copper localization took place in the cortex. Elemental analyses of L. sierrae and three other species from the same localities showed high enrichments of copper and selenium, suggesting that copper selenates or selenites might occur in these lichens and be responsible for the unusual colour. Copyright ?? 2011 British Lichen Society.

Copper localization, elemental content, and thallus colour in the copper hyperaccumulator lichen Lecanora sierra from California

USGS Publications Warehouse

Purvis, O.W.; Bennett, J.P.; Spratt, J.

2011-01-01

An unusual dark blue-green lichen, Lecanora sierrae, was discovered over 30 years ago by Czehura near copper mines in the Lights Creek District, Plumas County, Northern California. Using atomic absorption spectroscopy, Czehura found that dark green lichen samples from Warren Canyon contained 4% Cu in ash and suggested that its colour was due to copper accumulation in the cortex. The present study addressed the hypothesis that the green colour in similar material we sampled from Warren Canyon in 2008, is caused by copper localization in the thallus. Optical microscopy and electron microprobe analysis of specimens of L. sierrae confirmed that copper localization took place in the cortex. Elemental analyses of L. sierrae and three other species from the same localities showed high enrichments of copper and selenium, suggesting that copper selenates or selenites might occur in these lichens and be responsible for the unusual colour.

Studies on copper alloys containing chromium on the copper side phase diagram

NASA Technical Reports Server (NTRS)

Doi, T.

1984-01-01

Specimens were prepared from vacuum melted alloys of high purity vacuum melted copper and electrolytic chromium. The liquidus and eutectic point were determined by thermal analysis. The eutectic temperature is 1974.8 F and its composition is 1.28 wt% of chromium. The determination of solid solubility of chromium in copper was made by microscopic observation and electrical resistivity measurement. The solubility of chromium in solid copper is 0.6 wt% at 1050 F, 0.4 wt% at 1000 F, 0.25 wt% at 950 F, 0.17 wt% at 900 F, and 0.30 wt% at 840 F.

Untreated and copper-treated wood soaked in sodium oxalate: effects of decay by copper-tolerant and copper-sensitive fungi

Treesearch

Katie M. Ohno; Grant T. Kirker; Amy B. Bishell; Carol A. Clausen

2017-01-01

Copper is widely used as the primary component in wood protectants because it demonstrates a broad range of biocidal properties. However, a key concern with using copper in wood preservative formulations is the possibility for brown-rot basidiomycetes to resist the toxic effect. Many brown-rot basidiomycetes have evolved mechanisms, like the production and accumulation...

Copper Recycling in the United States in 2004

USGS Publications Warehouse

Goonan, Thomas G.

2009-01-01

As one of a series of reports that describe the recycling of metal commodities in the United States, this report discusses the flow of copper from production through distribution and use, with particular emphasis on the recycling of industrial scrap (new scrap1) and used products (old scrap) in the year 2004. This materials flow study includes a description of copper supply and demand for the United States to illustrate the extent of copper recycling and to identify recycling trends. Understanding how materials flow from a source through disposition can aid in improving the management of natural resource delivery systems. In 2004, the U.S. refined copper supply was 2.53 million metric tons (Mt) of refined unalloyed copper. With adjustment for refined copper exports of 127,000 metric tons (t) of copper, the net U.S. refined copper supply was 2.14 Mt of copper. With this net supply and a consumer inventory decrease of 9,000 t of refined copper, 2.42 Mt of refined copper was consumed by U.S. semifabricators (brass mills, wire rod mills, ingot makers, and foundries and others) in 2004. In addition to the 2.42 Mt of refined copper consumed in 2004, U.S. copper semifabricators consumed 853,000 t of copper contained in recycled scrap. Furthermore, 61,000 t of copper contained in scrap was consumed by noncopper alloy makers, for example, steelmakers and aluminum alloy makers. Old scrap recycling efficiency for copper was estimated to be 43 percent of theoretical old scrap supply, the recycling rate for copper was 30 percent of apparent supply, and the new-scrap-to-old-scrap ratio for U.S. copper product production was 3.2 (76:24).

Copper Resistance of the Emerging Pathogen Acinetobacter baumannii

PubMed Central

Williams, Caitlin L.; Neu, Heather M.; Gilbreath, Jeremy J.; Michel, Sarah L. J.; Zurawski, Daniel V.

2016-01-01

ABSTRACT Acinetobacter baumannii is an important emerging pathogen that is capable of causing many types of severe infection, especially in immunocompromised hosts. Since A. baumannii can rapidly acquire antibiotic resistance genes, many infections are on the verge of being untreatable, and novel therapies are desperately needed. To investigate the potential utility of copper-based antibacterial strategies against Acinetobacter infections, we characterized copper resistance in a panel of recent clinical A. baumannii isolates. Exposure to increasing concentrations of copper in liquid culture and on solid surfaces resulted in dose-dependent and strain-dependent effects; levels of copper resistance varied broadly across isolates, possibly resulting from identified genotypic variation among strains. Examination of the growth-phase-dependent effect of copper on A. baumannii revealed that resistance to copper increased dramatically in stationary phase. Moreover, A. baumannii biofilms were more resistant to copper than planktonic cells but were still susceptible to copper toxicity. Exposure of bacteria to subinhibitory concentrations of copper allowed them to better adapt to and grow in high concentrations of copper; this copper tolerance response is likely achieved via increased expression of copper resistance mechanisms. Indeed, genomic analysis revealed numerous putative copper resistance proteins that share amino acid homology to known proteins in Escherichia coli and Pseudomonas aeruginosa. Transcriptional analysis revealed significant upregulation of these putative copper resistance genes following brief copper exposure. Future characterization of copper resistance mechanisms may aid in the search for novel antibiotics against Acinetobacter and other highly antibiotic-resistant pathogens. IMPORTANCE Acinetobacter baumannii causes many types of severe nosocomial infections; unfortunately, some isolates have acquired resistance to almost every available antibiotic

Biodegradable chelate enhances the phytoextraction of copper by Oenothera picensis grown in copper-contaminated acid soils.

PubMed

González, Isabel; Cortes, Amparo; Neaman, Alexander; Rubio, Patricio

2011-07-01

Oenothera picensis plants (Fragrant Evening Primrose) grow in the acid soils contaminated by copper smelting in the coastal region of central Chile. We evaluated the effects of the biodegradable chelate MGDA (methylglycinediacetic acid) on copper extraction by O. picensis and on leaching of copper through the soil profile, using an ex situ experiment with soil columns of varying heights. MGDA was applied in four rates: 0 (control), 2, 6 and 10 mmol plant(-1). MGDA application significantly increased biomass production and foliar concentration, permitting an effective increase in copper extraction, from 0.09 mg plant(-1) in the control, to 1.3mg plant(-1) in the 6 and 10 mmol plant(-1) treatments. With 10 mmol plant(-1) rate of MGDA, the copper concentration in the leachate from the 30 cm columns was 20 times higher than in the control. For the 60 cm columns, copper concentration was 2 times higher than the control. It can be concluded that at increased soil depths, copper leaching would be minimal and that MGDA applications at the studied rates would not pose a high risk for leaching into groundwater. It can thus be stated that applications of MGDA are an effective and environmentally safe way to improve copper extraction by O. picensis in these soils. Copyright © 2011 Elsevier Ltd. All rights reserved.

Characterization of commercially cold sprayed copper coatings and determination of the effects of impacting copper powder velocities

NASA Astrophysics Data System (ADS)

Jakupi, P.; Keech, P. G.; Barker, I.; Ramamurthy, S.; Jacklin, R. L.; Shoesmith, D. W.; Moser, D. E.

2015-11-01

Copper coated steel containers are being developed for the disposal of high level nuclear waste using processes such as cold spray and electrodeposition. Electron Back-Scatter Diffraction has been used to determine the microstructural properties and the quality of the steel-copper coating interface. The influence of the nature of the cold-spray carrier gas as well as its temperature and pressure (velocity) on the coating's plastic strain and recrystallization behaviour have been investigated, and one commercially-produced electrodeposited coating characterized. The quality of the coatings was assessed using the coincident site lattice model to analyse the properties of the grain boundaries. For cold spray coatings the grain size and number of coincident site lattice grain boundaries increased, and plastic strain decreased, with carrier gas velocity. In all cases annealing improved the quality of the coatings by increasing texture and coincidence site-lattices, but also increased the number of physical voids, especially when a low temperature cold spray carrier gas was used. Comparatively, the average grain size and number of coincident site-lattices was considerably larger for the strongly textured electrodeposited coating. Tensile testing showed the electrodeposited coating was much more strongly adherent to the steel substrate.

Solvent polarity effect on quality of n-octadecanethiol self-assembled monolayers on copper and oxidized copper

NASA Astrophysics Data System (ADS)

Zhang, Yaozhong; Zhou, Jun; Zhang, Xiaoli; Hu, Jun; Gao, Han

2014-11-01

This article reports the effect of solvent polarity on the formation of n-octadecanethiol self-assembled monolayers (C18SH-SAMs) on pure copper surface and oxidized copper surface. The quality of SAMs prepared in different solvents (n-hexane, toluene, trichloroethylene, chloroform, acetone, acetonitrile, ethanol) was monitored by EIS, RAIRS and XPS. The results indicated that C18SH-SAMs formed in these solvents were in good barrier properties on pure copper surface and the structures of monolayers formed in high polarity solvents were more compact and orderly than that formed in low polarity solvents. For comparison, C18SH adsorbed on the surface of oxidized copper in these solvents were studied and the results indicated that C18SH could be adsorbed on oxidized copper surface after the reduction of copper oxide layer by thiols. Compared with high polarity solvents, a limited reduction process of oxidized copper by thiols led to the incompletely formation of monolayers in low polarity solvents. This can be interpreted that the generated water on solid-liquid interface and a smaller reaction force restrict the continuous reduction reaction in low polarity solvents

Blasted copper slag as fine aggregate in Portland cement concrete.

PubMed

Dos Anjos, M A G; Sales, A T C; Andrade, N

2017-07-01

The present work focuses on assessing the viability of applying blasted copper slag, produced during abrasive blasting, as fine aggregate for Portland cement concrete manufacturing, resulting in an alternative and safe disposal method. Leaching assays showed no toxicity for this material. Concrete mixtures were produced, with high aggregate replacement ratios, varying from 0% to 100%. Axial compressive strength, diametrical compressive strength, elastic modulus, physical indexes and durability were evaluated. Assays showed a significant improvement in workability, with the increase in substitution of fine aggregate. With 80% of replacement, the concrete presented lower levels of water absorption capacity. Axial compressive strength and diametrical compressive strength decreased, with the increase of residue replacement content. The greatest reductions of compressive strength were found when the replacement was over 40%. For tensile strength by diametrical compression, the greatest reduction occurred for the concrete with 80% of replacement. After the accelerated aging, results of mechanic properties showed a small reduction of the concrete with blasted copper slag performance, when compared with the reference mixture. Results indicated that the blasted copper slag is a technically viable material for application as fine aggregate for concrete mixtures. Copyright © 2017 Elsevier Ltd. All rights reserved.

Void growth and coalescence in irradiated copper under deformation

NASA Astrophysics Data System (ADS)

Barrioz, P. O.; Hure, J.; Tanguy, B.

2018-04-01

A decrease of fracture toughness of irradiated materials is usually observed, as reported for austenitic stainless steels in Light Water Reactors (LWRs) or copper alloys for fusion applications. For a wide range of applications (e.g. structural steels irradiated at low homologous temperature), void growth and coalescence fracture mechanism has been shown to be still predominant. As a consequence, a comprehensive study of the effects of irradiation-induced hardening mechanisms on void growth and coalescence in irradiated materials is required. The effects of irradiation on ductile fracture mechanisms - void growth to coalescence - are assessed in this study based on model experiments. Pure copper thin tensile samples have been irradiated with protons up to 0.01 dpa. Micron-scale holes drilled through the thickness of these samples subjected to uniaxial loading conditions allow a detailed description of void growth and coalescence. In this study, experimental data show that physical mechanisms of micron-scale void growth and coalescence are similar between the unirradiated and irradiated copper. However, an acceleration of void growth is observed in the later case, resulting in earlier coalescence, which is consistent with the decrease of fracture toughness reported in irradiated materials. These results are qualitatively reproduced with numerical simulations accounting for irradiation macroscopic hardening and decrease of strain-hardening capability.

Estimating Dermal Transfer of Copper Particles from the ...

EPA Pesticide Factsheets

Lumber pressure-treated with micronized copper was examined for the release of copper and copper micro/nanoparticles using a surface wipe method to simulate dermal transfer. In 2003, the wood industry began replacing CCA treated lumber products for residential use with copper based formulations. Micronized copper (nano to micron sized particles) has become the preferred treatment formulation. There is a lack of information on the release of copper, the fate of the particles during dermal contact, and the copper exposure level to children from hand-to-mouth transfer. For the current study, three treated lumber products, two micronized copper and one ionic copper, were purchased from commercial retailers. The boards were left to weather outdoors for approximately 1 year. Over the year time period, hand wipe samples were collected periodically to determine copper transfer from the wood surfaces. The two micronized formulations and the ionic formulation released similar levels of total copper. The amount of copper released was high initially, but decreased to a constant level (~1.5 mg m-2) after the first month of outdoor exposure. Copper particles were identified on the sampling cloths during the first two months of the experiment, after which the levels of copper were insufficient to collect interpretable data. After 1 month, the particles exhibited minimal changes in shape and size. At the end of 2-months, significant deterioration of the particles was

Fabricating and strengthening the carbon nanotube/copper composite fibers with high strength and high electrical conductivity

NASA Astrophysics Data System (ADS)

Han, Baoshuai; Guo, Enyu; Xue, Xiang; Zhao, Zhiyong; Li, Tiejun; Xu, Yanjin; Luo, Liangshun; Hou, Hongliang

2018-05-01

Combining the excellent properties of carbon nanotube (CNT) and copper, CNT/Cu composite fibers were fabricated by physical vapor deposition (PVD) and rolling treatment. Dense and continuous copper film (∼2 μm) was coated on the surface of the CNT fibers by PVD, and rolling treatment was adopt to strengthen the CNT/Cu composite fibers. After the rolling treatment, the defects between the Cu grains and the CNT bundles were eliminated, and the structure of both the copper film and the core CNT fibers were optimized. The rolled CNT/Cu composite fibers possess high tensile effective strength (1.01 ± 0.13 GPa) and high electrical conductivity ((2.6 ± 0.3) × 107 S/m), and thus, this material may become a promising wire material.

Long-distance connections in the Copper Age: New evidence from the Alpine Iceman's copper axe.

PubMed

Artioli, Gilberto; Angelini, Ivana; Kaufmann, Günther; Canovaro, Caterina; Dal Sasso, Gregorio; Villa, Igor Maria

2017-01-01

25 years after the discovery in the Ötztal Italian Alps, the 5,300-year-old mummy keeps providing key information on human biological and medical conditions, aspects of everyday life and societal organization in the Copper Age. The hand axe found with the body of the Alpine Iceman is one of the rare copper objects that is firmly dated to the early Copper Age because of the radiocarbon dating of the axe wooden shaft. Here we report the measurement of the lead isotope ratios of the copper blade. The results unambiguously indicate that the source of the metal is the ore-rich area of Southern Tuscany, despite ample evidence that Alpine copper ore sources were known and exploited at the time. The experimental results are discussed within the framework of all the available coeval archaeometallurgical data in Central-Southern Europe: they show that the Alps were a neat cultural barrier separating distinct metal circuits. The direct evidence of raw metal or object movement between Central Italy and the Alps is surprising and provides a new perspective on long-distance relocation of goods and relationships between the early Copper Age cultures in the area. The result is in line with the recent investigations re-evaluating the timing and extent of copper production in Central Italy in the 4th millennium BC.

Copper-2 Ingestion, Plus Increased Meat Eating Leading to Increased Copper Absorption, Are Major Factors Behind the Current Epidemic of Alzheimer’s Disease

PubMed Central

Brewer, George J.

2015-01-01

It has become clear that copper toxicity is playing a major role in Alzheimer’s disease; but why is the brain copper toxicity with cognition loss in Alzheimer’s disease so much different clinically than brain copper toxicity in Wilson’s disease, which results in a movement disorder? Furthermore, why is the inorganic copper of supplement pills and in drinking water so much more damaging to cognition than the organic copper in food? A recent paper, which shows that almost all food copper is copper-1, that is the copper-2 of foods reverts to the reduced copper-1 form at death or harvest, gives new insight into these questions. The body has an intestinal transport system for copper-1, Ctr1, which channels copper-1 through the liver and into safe channels. Ctr1 cannot absorb copper-2, and some copper-2 bypasses the liver, ends up in the blood quickly, and is toxic to cognition. Humans evolved to handle copper-1 safely, but not copper-2. Alzheimer’s is at least in part, a copper-2 toxicity disease, while Wilson’s is a general copper overload disease. In this review, we will show that the epidemiology of the Alzheimer’s epidemic occurring in developed, but not undeveloped countries, fits with the epidemiology of exposure to copper-2 ingestion leached from copper plumbing and from copper supplement pill ingestion. Increased meat eating in developed countries is also a factor, because it increases copper absorption, and thus over all copper exposure. PMID:26633489

Metabolic crossroads of iron and copper

PubMed Central

Collins, James F; Prohaska, Joseph R; Knutson, Mitchell D

2013-01-01

Interactions between the essential dietary metals, iron and copper, have been known for many years. This review highlights recent advances in iron-copper interactions with a focus on tissues and cell types important for regulating whole-body iron and copper homeostasis. Cells that mediate dietary assimilation (enterocytes) and storage and distribution (hepatocytes) of iron and copper are considered, along with the principal users (erythroid cells) and recyclers of red cell iron (reticuloendothelial macrophages). Interactions between iron and copper in the brain are also discussed. Many unanswered questions regarding the role of these metals and their interactions in health and disease emerge from this synopsis, highlighting extensive future research opportunities. PMID:20384844

Chronic copper poisoning in Angora kids.

PubMed

Belford, C J; Raven, C R; Black, H

1989-12-01

The investigation of five field cases of chronic copper poisoning in a group of 100 Angora kids is reported. Toxicity was confirmed by the demonstration of Heinz body anaemias, necrotizing liver disease, haemoglobinuric nephrosis and excessive levels of copper in blood, livers and kidneys. The dietary history of the kids is described. Tissue levels of copper and reported interactions between selenium, zinc and copper are discussed. Therapeutic and preventative measures are suggested.

Asymptotic Slavery in the Copper Oxide High Temperature Superconductors

NASA Astrophysics Data System (ADS)

Phillips, Philip

2004-05-01

Vast progress in theoretical solid state physics has been made by constructing models which mimic the low-energy properties of solids. Essential to the success of this program is the separability of the high and low energy degrees of freedom. While it is hoped that a high energy reduction can be made to solve the problem of high temperature superconductivity in the copper oxide materials, I will show that no consistent theory is possible if the high energy scale is removed. At the heart of the problem is the mixing of all energy scales (that is, UV-IR mixing) in the copper-oxide materials. Optical experiments demonstrate that the number of low-energy degrees of freedom is derived from a high energy scale. The implications of the inseparability of the high and low energy degrees of freedom on the phase diagram of the cuprates is discussed.

Polystyrene films as barrier layers for corrosion protection of copper and copper alloys.

PubMed

Románszki, Loránd; Datsenko, Iaryna; May, Zoltán; Telegdi, Judit; Nyikos, Lajos; Sand, Wolfgang

2014-06-01

Dip-coated polystyrene layers of sub-micrometre thickness (85-500nm) have been applied on copper and copper alloys (aluminium brass, copper-nickel 70/30), as well as on stainless steel 304, and produced an effective barrier against corrosion and adhesion of corrosion-relevant microorganisms. According to the dynamic wettability measurements, the coatings exhibited high advancing (103°), receding (79°) and equilibrium (87°) contact angles, low contact angle hysteresis (6°) and surface free energy (31mJ/m(2)). The corrosion rate of copper-nickel 70/30 alloy samples in 3.5% NaCl was as low as 3.2μm/a (44% of that of the uncoated samples), and in artificial seawater was only 0.9μm/a (29% of that of the uncoated samples). Cell adhesion was studied by fluorescence microscopy, using monoculture of Desulfovibrio alaskensis. The coatings not only decreased the corrosion rate but also markedly reduced the number of bacterial cells adhered to the coated surfaces. The PS coating on copper gave the best result, 2×10(3)cells/cm(2) (1% of that of the uncoated control). © 2013 Elsevier B.V. All rights reserved.

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

Roles of Copper-Binding Proteins in Breast Cancer.

PubMed

Blockhuys, Stéphanie; Wittung-Stafshede, Pernilla

2017-04-20

Copper ions are needed in several steps of cancer progression. However, the underlying mechanisms, and involved copper-binding proteins, are mainly elusive. Since most copper ions in the body (in and outside cells) are protein-bound, it is important to investigate what copper-binding proteins participate and, for these, how they are loaded with copper by copper transport proteins. Mechanistic information for how some copper-binding proteins, such as extracellular lysyl oxidase (LOX), play roles in cancer have been elucidated but there is still much to learn from a biophysical molecular viewpoint. Here we provide a summary of copper-binding proteins and discuss ones reported to have roles in cancer. We specifically focus on how copper-binding proteins such as mediator of cell motility 1 (MEMO1), LOX, LOX-like proteins, and secreted protein acidic and rich in cysteine (SPARC) modulate breast cancer from molecular and clinical aspects. Because of the importance of copper for invasion/migration processes, which are key components of cancer metastasis, further insights into the actions of copper-binding proteins may provide new targets to combat cancer.

The trade-off of availability and growth inhibition through copper for the production of copper-dependent enzymes by Pichia pastoris.

PubMed

Balakumaran, Palanisamy Athiyaman; Förster, Jan; Zimmermann, Martin; Charumathi, Jayachandran; Schmitz, Andreas; Czarnotta, Eik; Lehnen, Mathias; Sudarsan, Suresh; Ebert, Birgitta E; Blank, Lars Mathias; Meenakshisundaram, Sankaranarayanan

2016-02-20

Copper is an essential chemical element for life as it is a part of prosthetic groups of enzymes including super oxide dismutase and cytochrome c oxidase; however, it is also toxic at high concentrations. Here, we present the trade-off of copper availability and growth inhibition of a common host used for copper-dependent protein production, Pichia pastoris. At copper concentrations ranging from 0.1 mM (6.35 mg/L) to 2 mM (127 mg/L), growth rates of 0.25 h(-1) to 0.16 h(-1) were observed with copper uptake of as high as 20 mgcopper/gCDW. The intracellular copper content was estimated by subtracting the copper adsorbed on the cell wall from the total copper concentration in the biomass. Higher copper concentrations led to stronger cell growth retardation and, at 10 mM (635 mg/L) and above, to growth inhibition. To test the determined copper concentration range for optimal recombinant protein production, a laccase gene from Aspergillus clavatus [EMBL: EAW07265.1] was cloned under the control of the constitutive glyceraldehyde-3-phosphate (GAP) dehydrogenase promoter for expression in P. pastoris. Notably, in the presence of copper, laccase expression improved the specific growth rate of P. pastoris. Although copper concentrations of 0.1 mM and 0.2 mM augmented laccase expression 4 times up to 3 U/mL compared to the control (0.75 U/mL), while higher copper concentrations resulted in reduced laccase production. An intracellular copper content between 1 and 2 mgcopper/gCDW was sufficient for increased laccase activity. The physiology of the yeast could be excluded as a reason for the stop of laccase production at moderate copper concentrations as no flux redistribution could be observed by (13)C-metabolic flux analysis. Copper and its pivotal role to sustain cellular functions is noteworthy. However, knowledge on its cellular accumulation, availability and distribution for recombinant protein production is limited. This study attempts to address one such challenge

Experimental and Theoretical Investigation of Thiazolyl Blue as a Corrosion Inhibitor for Copper in Neutral Sodium Chloride Solution.

PubMed

Feng, Li; Zhang, Shengtao; Qiang, Yujie; Xu, Yue; Guo, Lei; Madkour, Loutfy H; Chen, Shijin

2018-06-19

The anticorrosion effect of thiazolyl blue (MTT) for copper in 3% NaCl at 298 K was researched by electrochemical methods, scanning electron-microscopy (SEM), and atomic force microscopy (AFM). The results reveal that MTT can protect copper efficiently, with a maximum efficiency of 95.7%. The corrosion inhibition mechanism was investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectral (FT-IR), and theoretical calculation. The results suggest that the MTT molecules are adsorbed on metal surface forming a hydrophobic protective film to prevent copper corrosion. It also indicates that the MTT and copper form covalent bonds. The molecular dynamic simulation further gives the evidence for adsorption. The adsorption isotherm studies demonstrate that a spontaneous, mixed physical and chemical adsorption occurs, which obeys Langmuir adsorption isotherm. The present research can help us better understand the corrosion inhibition process and improve it.

Lead and Copper Rule Tier Schedule

EPA Pesticide Factsheets

The Lead and Copper Rule Tier Schedule may be used by public water systems in Wyoming and on EPA R8 Tribal Lands as a guide to properly identify their lead and copper tap sample sites to comply with the Lead and Copper Rule.

High-Speed Wind-Tunnel Investigation of the Lateral Stability Characteristics of a 0.10-Scale Model of the Grumman XF9F-2 Airplane, TED No. NACA DE 301

NASA Technical Reports Server (NTRS)

Polhamus, Edward C.; King, Thomas J., Jr.

1949-01-01

An investigation was made in the Langley high-speed 7- by 10-foot tunnel to determine the high-speed lateral and directional stability characteristics of a 0.10-scale model of the Grumman XF9F-2 airplane in the Mach number range from 0.40 to 0.85. The results indicate that static lateral and directional stability is present throughout the Mach number range investigated although in the Mach number range from 0.75 to 0.85 there is an appreciable decrease in rolling moment due to sideslip. Calculations of the dynamic stability indicate that according to current flying-quality requirements the damping of the lateral oscillation, although probably satisfactory for the sea-level condition, may not be satisfactory for the majority of the altitude conditions investigated

Oxidation-assisted graphene heteroepitaxy on copper foil.

PubMed

Reckinger, Nicolas; Tang, Xiaohui; Joucken, Frédéric; Lajaunie, Luc; Arenal, Raul; Dubois, Emmanuel; Hackens, Benoît; Henrard, Luc; Colomer, Jean-François

2016-11-10

We propose an innovative, easy-to-implement approach to synthesize aligned large-area single-crystalline graphene flakes by chemical vapor deposition on copper foil. This method doubly takes advantage of residual oxygen present in the gas phase. First, by slightly oxidizing the copper surface, we induce grain boundary pinning in copper and, in consequence, the freezing of the thermal recrystallization process. Subsequent reduction of copper under hydrogen suddenly unlocks the delayed reconstruction, favoring the growth of centimeter-sized copper (111) grains through the mechanism of abnormal grain growth. Second, the oxidation of the copper surface also drastically reduces the nucleation density of graphene. This oxidation/reduction sequence leads to the synthesis of aligned millimeter-sized monolayer graphene domains in epitaxial registry with copper (111). The as-grown graphene flakes are demonstrated to be both single-crystalline and of high quality.

Copper metallothioneins.

PubMed

Calvo, Jenifer; Jung, Hunmin; Meloni, Gabriele

2017-04-01

Metallothioneins (MTs) are a class of low molecular weight and cysteine-rich metal binding proteins present in all the branches of the tree of life. MTs efficiently bind with high affinity several essential and toxic divalent and monovalent transition metals by forming characteristic polynuclear metal-thiolate clusters within their structure. MTs fulfil multiple biological functions related to their metal binding properties, with essential roles in both Zn(II) and Cu(I) homeostasis as well as metal detoxification. Depending on the organism considered, the primary sequence, and the specific physiological and metabolic status, Cu(I)-bound MT isoforms have been isolated, and their chemistry and biology characterized. Besides the recognized role in the biochemistry of divalent metals, it is becoming evident that unique biological functions in selectively controlling copper levels, its reactivity as well as copper-mediated biochemical processes have evolved in some members of the MT superfamily. Selected examples are reviewed to highlight the peculiar chemical properties and biological functions of copper MTs. © 2016 IUBMB Life, 69(4):236-245, 2017. © 2017 International Union of Biochemistry and Molecular Biology.

CorA Is a Copper Repressible Surface-Associated Copper(I)-Binding Protein Produced in Methylomicrobium album BG8

PubMed Central

Johnson, Kenneth A.; Ve, Thomas; Larsen, Øivind; Pedersen, Rolf B.; Lillehaug, Johan R.; Jensen, Harald B.; Helland, Ronny; Karlsen, Odd A.

2014-01-01

CorA is a copper repressible protein previously identified in the methanotrophic bacterium Methylomicrobium album BG8. In this work, we demonstrate that CorA is located on the cell surface and binds one copper ion per protein molecule, which, based on X-ray Absorption Near Edge Structure analysis, is in the reduced state (Cu(I)). The structure of endogenously expressed CorA was solved using X-ray crystallography. The 1.6 Å three-dimensional structure confirmed the binding of copper and revealed that the copper atom was coordinated in a mononuclear binding site defined by two histidines, one water molecule, and the tryptophan metabolite, kynurenine. This arrangement of the copper-binding site is similar to that of its homologous protein MopE* from Metylococcus capsulatus Bath, confirming the importance of kynurenine for copper binding in these proteins. Our findings show that CorA has an overall fold similar to MopE, including the unique copper(I)-binding site and most of the secondary structure elements. We suggest that CorA plays a role in the M. album BG8 copper acquisition. PMID:24498370

Carbohydrate metabolism in erythrocytes of copper deficient rats.

PubMed

Brooks, S P J; Cockell, K A; Dawson, B A; Ratnayake, W M N; Lampi, B J; Belonje, B; Black, D B; Plouffe, L J

2003-11-01

Dietary copper deficiency is known to adversely affect the circulatory system of fructose-fed rats. Part of the problem may lie in the effect of copper deficiency on intermediary metabolism. To test this, weanling male Long-Evans rats were fed for 4 or 8 weeks on sucrose-based diets containing low or adequate copper content. Copper deficient rats had significantly lower plasma and tissue copper as well as lower plasma copper, zinc-superoxide dismutase activity. Copper deficient rats also had a significantly higher heart:body weight ratio when compared to pair-fed controls. Direct measurement of glycolysis and pentose phosphate pathway flux in erythrocytes using (13)C NMR showed no differences in carbon flux from glucose or fructose to pyruvate but a significantly higher flux through the lactate dehydrogenase locus in copper deficient rats (approximately 1.3 times, average of glucose and glucose + fructose measurements). Copper-deficient animals had significantly higher erythrocyte concentrations of glucose, fructose, glyceraldehyde 3-phosphate and NAD(+). Liver metabolite levels were also affected by copper deficiency being elevated in glycogen and fructose 1-phosphate content. The results show small changes in carbohydrate metabolism of copper deficient rats.

Zinc stress induces copper depletion in Acinetobacter baumannii.

PubMed

Hassan, Karl A; Pederick, Victoria G; Elbourne, Liam D H; Paulsen, Ian T; Paton, James C; McDevitt, Christopher A; Eijkelkamp, Bart A

2017-03-11

The first row transition metal ions zinc and copper are essential to the survival of many organisms, although in excess these ions are associated with significant toxicity. Here, we examined the impact of zinc and copper stress on Acinetobacter baumannii, a common opportunistic pathogen. We show that extracellular zinc stress induces a copper-specific depletion phenotype in A. baumannii ATCC 17978. Supplementation with copper not only fails to rescue this phenotype, but further exacerbates the copper depletion. Extensive analysis of the A. baumannii ATCC 17978 genome identified 13 putative zinc/copper resistance efflux pumps. Transcriptional analyses show that four of these transporters are responsive to zinc stress, five to copper stress and seven to the combination of zinc and copper stress, thereby revealing a likely foundation for the zinc-induced copper starvation in A. baumannii. In addition, we show that zinc and copper play crucial roles in management of oxidative stress and the membrane composition of A. baumannii. Further, we reveal that zinc and copper play distinct roles in macrophage-mediated killing of this pathogen. Collectively, this study supports the targeting of metal ion homeostatic mechanisms as an effective antimicrobial strategy against multi-drug resistant bacterial pathogens.

The effects of soil liming and sewage sludge application on dynamics of copper fractions and total copper concentration.

PubMed

Malinowska, Elżbieta

2016-10-01

The paper deals with effects of liming and different doses of municipal sewage sludge (5, 10, and 15 % of soil mass) on copper speciation in soil. In all samples, pH was determined together with total copper concentration, which was measured with the ICP-AES method. Concentration of copper chemical fractions was determined using the seven-step procedure of Zeien and Brümmer. In the soil treated with the highest dose of sludge (15 %), there was, compared to the control, a twofold increase in the concentration of copper and a threefold increase in the concentration of nitrogen. Copper speciation analysis showed that in the municipal sewage sludge the easily soluble and exchangeable fractions (F1 and F2) constituted only a small share of copper with the highest amount of this metal in the organic (F4) and residual (F7) fractions. In the soil, at the beginning of the experiment, the highest share was in the organic fraction (F4), the residual fraction (F7) but also in the fraction where copper is bound to amorphous iron oxides (F5). After 420 days, at the end of the experiment, the highest amount of copper was mainly in the organic fraction (F4) and in the fraction with amorphous iron oxides (F5). Due to mineralization of organic matter in the sewage sludge, copper was released into the soil with the share of the residual fraction (F7) decreasing. In this fraction, there was much more copper in limed soil than in non-limed soil.

Geomorphology of the lower Copper River, Alaska

USGS Publications Warehouse

Brabets, T.P.

1996-01-01

The Copper River, located in southcentral Alaska, drains an area of more than 24,000 square miles. About 30 miles above its mouth, this large river enters Miles Lake, a proglacial lake formed by the retreat of Miles Glacier. Downstream from the outlet of Miles Lake, the Copper River flows past the face of Childs Glacier before it enters a large, broad, alluvial flood plain. The Copper River Highway traverses this flood plain and in 1996, 11 bridges were located along this section of the highway. These bridges cross parts or all of the Copper River and in recent years, some of these bridges have sustained serious damage due to the changing course of the Copper River. Although the annual mean discharge of the lower Copper River is 57,400 cubic feet per second, most of the flow occurs during the summer months from snowmelt, rainfall, and glacial melt. Approximately every six years, an outburst flood from Van Cleve Lake, a glacier-dammed lake formed by Miles Glacier, releases approximately 1 million acre-feet of water into the Copper River. At the peak outflow rate from Van Cleve Lake, the flow of the Copper River will increase an additional 140,000 and 190,000 cubic feet per second. Bedload sampling and continuous seismic reflection were used to show that Miles Lake traps virtually all the bedload being transported by the Copper River as it enters the lake from the north. The reservoir-like effect of Miles Lake results in the armoring of the channel of the Copper River downstream from Miles Lakes, past Childs Glacier, until it reaches the alluvial flood plain. At this point, bedload transport begins again. The lower Copper River transports 69 million tons per year of suspended sediment, approximately the same quantity as the Yukon River, which drains an area of more than 300,000 square miles. By correlating concurrent flows from a long-term streamflow- gaging station on the Copper River with a short-term streamflow-gaging station at the outlet of Miles Lake, long

Geomorphology of the lower Copper River, Alaska

USGS Publications Warehouse

Brabets, Timothy P.

1997-01-01

The Copper River, located in southcentral Alaska, drains an area of more than 24,000 square miles. About 30 miles above its mouth, this large river enters Miles Lake, a proglacial lake formed by the retreat of Miles Glacier. Downstream from the outlet of Miles Lake, the Copper River flows past the face of Childs Glacier before it enters a large, broad, alluvial flood plain. The Copper River Highway traverses this flood plain and in 1995, 11 bridges were located along this section of the highway. These bridges cross parts of the Copper River and in recent years, some of these bridges have sustained serious damage due to the changing course of the Copper River. Although the annual mean discharge of the lower Copper River is 57,400 cubic feet per second, most of the flow occurs during the summer months from snowmelt, rainfall, and glacial melt. Approximately every six years, an outburst flood from Van Cleve Lake, a glacier-dammed lake formed by Miles Glacier, releases approximately 1 million acre-feet of water into the Copper River. When the outflow rate from Van Cleve Lake reaches it peak, the flow of the Copper River will increase between 150,000 to 190,000 cubic feet per second. Data collected by bedload sampling and continuous seismic reflection indicated that Miles Lake traps virtually all the bedload being transported by the Copper River as it enters the lake from the north. The reservoir-like effect of Miles Lake results in the armoring of the channel of the Copper River downstream from Miles Lake, past Childs Glacier, until it reaches the alluvial flood plain. At this point, bedload transport begins again. The lower Copper River transports 69 million tons per year of suspended sediment, approximately the same quantity as the Yukon River, which drains an area of more than 300,000 square miles. By correlating concurrent flows from a long-term streamflow-gaging station on the Copper River with a short-term streamflow-gaging station at the outlet of Miles Lake

A study of the effects of phosphates on copper corrosion in drinking water: Copper release, electrochemical, and surface analysis approach

NASA Astrophysics Data System (ADS)

Kang, Young C.

The following work is the study to evaluate the impact of corrosion inhibitors on the copper metal in drinking water and to investigate the corrosion mechanism in the presence and absence of inhibitors. Electrochemical experiments were conducted to understand the effect of specific corrosion inhibitors in synthetic drinking water which was prepared with controlled specific water quality parameters. Water chemistry was studied by Inductively Coupled Plasma--Atomic Emission Spectroscopy (ICP--AES) to investigate the copper leaching rate with time. Surface morphology, crystallinity of corrosion products, copper oxidation status, and surface composition were characterized by various solid surface analysis methods, such as Scanning Electron Microscopy/Energy--Dispersive Spectrometry (SEM/EDS), Grazing-Incidence-angle X-ray Diffraction (GIXRD), X-ray Photoelectron Spectroscopy (XPS), and Time-of-Flight Secondary Ions Mass Spectrometry (ToF-SIMS). The purpose of the first set of experiments was to test various electrochemical techniques for copper corrosion for short term before studying a long term loop system. Surface analysis techniques were carried out to identify and study the corrosion products that form on the fresh copper metal surface when copper coupons were exposed to test solutions for 2 days of experiments time. The second phase of experiments was conducted with a copper pipe loop system in a synthetic tap water over an extended period of time, i.e., 4 months. Copper release and electrochemically measured corrosion activity profiles were monitored carefully with and without corrosion inhibitor, polyphosphate. A correlation between the copper released into the solution and the electrochemically measured corrosion activities was also attempted. To investigate corrosion products on the copper pipe samples, various surface analysis techniques were applied in this study. Especially, static mass spectra acquisition and element distribution mapping were carried out

Enrichment of copper and recycling of cyanide from copper-cyanide waste by solvent extraction

NASA Astrophysics Data System (ADS)

Gao, Teng-yue; Liu, Kui-ren; Han, Qing; Xu, Bin-shi

2016-11-01

The enrichment of copper from copper-cyanide wastewater by solvent extraction was investigated using a quaternary ammonium salt as an extractant. The influences of important parameters, e.g., organic-phase components, aqueous pH values, temperature, inorganic anion impurities, CN/Cu molar ratio, and stripping reagents, were examined systematically, and the optimal conditions were determined. The results indicated that copper was effectively concentrated from low-concentration solutions using Aliquat 336 and that the extraction efficiency increased linearly with increasing temperature. The aqueous pH value and concentrations of inorganic anion impurities only weakly affected the extraction process when varied in appropriate ranges. The CN/Cu molar ratio affected the extraction efficiency by changing the distribution of copper-cyanide complexes. The difference in gold leaching efficiency between using raffinate and fresh water was negligible.

Recovery of copper as zero-valent phase and/or copper oxide nanoparticles from wastewater by ferritization.

PubMed

Heuss-Aßbichler, Soraya; John, Melanie; Klapper, Daniel; Bläß, Ulrich W; Kochetov, Gennadii

2016-10-01

Recently the focus of interest changed from merely purification of the waste water to recover heavy metals. With the slightly modified ferritization process presented here it is possible to decrease initial Cu(2+) concentrations up to 10 g/l to values <0.3 mg/l. The recovery rates of copper of all experiments are in the rage of 99.98 to almost 100%. Copper can be precipitated as oxide or zero valent metal (almost) free of hydroxide. All precipitates are exclusively of nanoparticle size. The phase assemblage depends strongly on experimental conditions as e.g. reaction temperature, pH-value, initial concentration and ageing time and condition. Three different options were developed depending on the reaction conditions. Option 1.) copper incorporation into the ferrite structure ((Cu,Fe)Fe2O4) and/or precipitation as cuprite (Cu2O) and zero-valent copper, option 2.) copper incorporation into the ferrite structure and/or precipitation as cuprite and/or tenorite (CuO) and option 3.) copper precipitation as tenorite. Ferrite is formed by the oxidation of GR in alkaline solution without additional oxygen supply. The chemistry reaches from pure magnetite up to 45% copper ferrite component. First experiments with wastewater from electroplating industry confirm the results obtained from synthetic solutions. In all cases the volume of the precipitates is extremely low compared to typical wastewater treatment by hydroxide precipitation. Therefore, pollution and further dissipation of copper can be avoided using this simple and economic process. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hydrothermal growth of cross-linked hyperbranched copper dendrites using copper oxalate complex

NASA Astrophysics Data System (ADS)

Truong, Quang Duc; Kakihana, Masato

2012-06-01

A facile and surfactant-free approach has been developed for the synthesis of cross-linked hyperbranched copper dendrites using copper oxalate complex as a precursor and oxalic acid as a reducing and structure-directing agent. The synthesized particles are composed of highly branched nanostructures with unusual cross-linked hierarchical networks. The formation of copper dendrites can be explained in view of both diffusion control and aggregation-based growth model accompanied by the chelation-assisted assembly. Oxalic acid was found to play dual roles as reducing and structure-directing agent based on the investigation results. The understanding on the crystal growth and the roles of oxalic acid provides clear insight into the formation mechanism of hyperbranched metal dendrites.

Rapid Separation of Copper Phase and Iron-Rich Phase From Copper Slag at Low Temperature in a Super-Gravity Field

NASA Astrophysics Data System (ADS)

Lan, Xi; Gao, Jintao; Huang, Zili; Guo, Zhancheng

2018-03-01

A novel approach for quickly separating a metal copper phase and iron-rich phase from copper slag at low temperature is proposed based on a super-gravity method. The morphology and mineral evolution of the copper slag with increasing temperature were studied using in situ high-temperature confocal laser scanning microscopy and ex situ scanning electron microscopy and X-ray diffraction methods. Fe3O4 particles dispersed among the copper slag were transformed into FeO by adding an appropriate amount of carbon as a reducing agent, forming the slag melt with SiO2 at low temperature and assisting separation of the copper phase from the slag. Consequently, in a super-gravity field, the metallic copper and copper matte were concentrated as the copper phase along the super-gravity direction, whereas the iron-rich slag migrated in the opposite direction and was quickly separated from the copper phase. Increasing the gravity coefficient (G) significantly enhanced the separation efficiency. After super-gravity separation at G = 1000 and 1473 K (1200 °C) for 3 minutes, the mass fraction of Cu in the separated copper phase reached 86.11 wt pct, while that in the separated iron-rich phase was reduced to 0.105 wt pct. The recovery ratio of Cu in the copper phase was as high as up to 97.47 pct.

Rapid Separation of Copper Phase and Iron-Rich Phase From Copper Slag at Low Temperature in a Super-Gravity Field

NASA Astrophysics Data System (ADS)

Lan, Xi; Gao, Jintao; Huang, Zili; Guo, Zhancheng

2018-06-01

A novel approach for quickly separating a metal copper phase and iron-rich phase from copper slag at low temperature is proposed based on a super-gravity method. The morphology and mineral evolution of the copper slag with increasing temperature were studied using in situ high-temperature confocal laser scanning microscopy and ex situ scanning electron microscopy and X-ray diffraction methods. Fe3O4 particles dispersed among the copper slag were transformed into FeO by adding an appropriate amount of carbon as a reducing agent, forming the slag melt with SiO2 at low temperature and assisting separation of the copper phase from the slag. Consequently, in a super-gravity field, the metallic copper and copper matte were concentrated as the copper phase along the super-gravity direction, whereas the iron-rich slag migrated in the opposite direction and was quickly separated from the copper phase. Increasing the gravity coefficient (G) significantly enhanced the separation efficiency. After super-gravity separation at G = 1000 and 1473 K (1200 °C) for 3 minutes, the mass fraction of Cu in the separated copper phase reached 86.11 wt pct, while that in the separated iron-rich phase was reduced to 0.105 wt pct. The recovery ratio of Cu in the copper phase was as high as up to 97.47 pct.

Surface structure influences contact killing of bacteria by copper

PubMed Central

Zeiger, Marco; Solioz, Marc; Edongué, Hervais; Arzt, Eduard; Schneider, Andreas S

2014-01-01

Copper kills bacteria rapidly by a mechanism that is not yet fully resolved. The antibacterial property of copper has raised interest in its use in hospitals, in place of plastic or stainless steel. On the latter surfaces, bacteria can survive for days or even weeks. Copper surfaces could thus provide a powerful accessory measure to curb nosocomial infections. We here investigated the effect of the copper surface structure on the efficiency of contact killing of Escherichia coli, an aspect which so far has received very little attention. It was shown that electroplated copper surfaces killed bacteria more rapidly than either polished copper or native rolled copper. The release of ionic copper was also more rapid from electroplated copper compared to the other materials. Scanning electron microscopy revealed that the bacteria nudged into the grooves between the copper grains of deposited copper. The findings suggest that, in terms of contact killing, more efficient copper surfaces can be engineered. PMID:24740976

Aspergillus fumigatus Copper Export Machinery and Reactive Oxygen Intermediate Defense Counter Host Copper-Mediated Oxidative Antimicrobial Offense.

PubMed

Wiemann, Philipp; Perevitsky, Adi; Lim, Fang Yun; Shadkchan, Yana; Knox, Benjamin P; Landero Figueora, Julio A; Choera, Tsokyi; Niu, Mengyao; Steinberger, Andrew J; Wüthrich, Marcel; Idol, Rachel A; Klein, Bruce S; Dinauer, Mary C; Huttenlocher, Anna; Osherov, Nir; Keller, Nancy P

2017-05-02

The Fenton-chemistry-generating properties of copper ions are considered a potent phagolysosome defense against pathogenic microbes, yet our understanding of underlying host/microbe dynamics remains unclear. We address this issue in invasive aspergillosis and demonstrate that host and fungal responses inextricably connect copper and reactive oxygen intermediate (ROI) mechanisms. Loss of the copper-binding transcription factor AceA yields an Aspergillus fumigatus strain displaying increased sensitivity to copper and ROI in vitro, increased intracellular copper concentrations, decreased survival in challenge with murine alveolar macrophages (AMΦs), and reduced virulence in a non-neutropenic murine model. ΔaceA survival is remediated by dampening of host ROI (chemically or genetically) or enhancement of copper-exporting activity (CrpA) in A. fumigatus. Our study exposes a complex host/microbe multifactorial interplay that highlights the importance of host immune status and reveals key targetable A. fumigatus counter-defenses. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Biosorption of copper by cyanobacterial bloom-derived biomass harvested from the eutrophic Lake Dianchi in China.

PubMed

Wang, Kan; Colica, Giovanni; De Philippis, Roberto; Liu, Yongding; Li, Dunhai

2010-10-01

Biomass of cyanobacterial bloom from Lake Dianchi was used as a biosorbent for copper removal from aqueous solution. The maximum capacity was found at conditions of pH 4, initial concentration of copper was 10 mg/l and initial dose of biomass was 1.0 g/l. HNO(3) demonstrated the highest desorption efficiency compared with HCl, EDTA, and citric acid. Physical adsorption was assumed not to be the dominant mechanism of biosorption as revealed by scanning electron microscopy and surface area measurement of the biomass. Infrared ray spectra analysis of the biomass suggested that ion-exchange is the principal mechanism for biosorption. Considering the advantages-low cost, easy to collect, and huge in quantity-the Microcystis bloom biomass could be used as a sorbent for copper and other heavy metals removal.

Body of Knowledge (BOK) for Copper Wire Bonds

NASA Technical Reports Server (NTRS)

Rutkowski, E.; Sampson, M. J.

2015-01-01

Copper wire bonds have replaced gold wire bonds in the majority of commercial semiconductor devices for the latest technology nodes. Although economics has been the driving mechanism to lower semiconductor packaging costs for a savings of about 20% by replacing gold wire bonds with copper, copper also has materials property advantages over gold. When compared to gold, copper has approximately: 25% lower electrical resistivity, 30% higher thermal conductivity, 75% higher tensile strength and 45% higher modulus of elasticity. Copper wire bonds on aluminum bond pads are also more mechanically robust over time and elevated temperature due to the slower intermetallic formation rate - approximately 1/100th that of the gold to aluminum intermetallic formation rate. However, there are significant tradeoffs with copper wire bonding - copper has twice the hardness of gold which results in a narrower bonding manufacturing process window and requires that the semiconductor companies design more mechanically rigid bonding pads to prevent cratering to both the bond pad and underlying chip structure. Furthermore, copper is significantly more prone to corrosion issues. The semiconductor packaging industry has responded to this corrosion concern by creating a palladium coated copper bonding wire, which is more corrosion resistant than pure copper bonding wire. Also, the selection of the device molding compound is critical because use of environmentally friendly green compounds can result in internal CTE (Coefficient of Thermal Expansion) mismatches with the copper wire bonds that can eventually lead to device failures during thermal cycling. Despite the difficult problems associated with the changeover to copper bonding wire, there are billions of copper wire bonded devices delivered annually to customers. It is noteworthy that Texas Instruments announced in October of 2014 that they are shipping microcircuits containing copper wire bonds for safety critical automotive applications

Long-distance connections in the Copper Age: New evidence from the Alpine Iceman’s copper axe

PubMed Central

Angelini, Ivana; Kaufmann, Günther; Canovaro, Caterina; Dal Sasso, Gregorio; Villa, Igor Maria

2017-01-01

25 years after the discovery in the Ötztal Italian Alps, the 5,300-year-old mummy keeps providing key information on human biological and medical conditions, aspects of everyday life and societal organization in the Copper Age. The hand axe found with the body of the Alpine Iceman is one of the rare copper objects that is firmly dated to the early Copper Age because of the radiocarbon dating of the axe wooden shaft. Here we report the measurement of the lead isotope ratios of the copper blade. The results unambiguously indicate that the source of the metal is the ore-rich area of Southern Tuscany, despite ample evidence that Alpine copper ore sources were known and exploited at the time. The experimental results are discussed within the framework of all the available coeval archaeometallurgical data in Central-Southern Europe: they show that the Alps were a neat cultural barrier separating distinct metal circuits. The direct evidence of raw metal or object movement between Central Italy and the Alps is surprising and provides a new perspective on long-distance relocation of goods and relationships between the early Copper Age cultures in the area. The result is in line with the recent investigations re-evaluating the timing and extent of copper production in Central Italy in the 4th millennium BC. PMID:28678801

The effect of copper from water and food: changes of serum nonceruloplasmin copper and brain's amyloid-beta in mice.

PubMed

Wu, Min; Han, Feifei; Gong, Weisha; Feng, Lifang; Han, Jianzhong

2016-09-14

Copper is an essential element and also produces adverse health consequences when overloaded. Food and water are the main sources of copper intake, however few studies have been conducted to investigate the difference between the ways of its intake in water and food in animals. In this study, copper was fed to mice with food as well as water (two groups: water and diet) for three months at concentrations of 6, 15 and 30 ppm. The copper concentration in water was adjusted for keeping the same amount during its intake in food. The experimental studies show a slow growth rate, lower hepatic reduced glutathione (GSH)/superoxide dismutase (SOD) activity and higher serum 'free' copper in the water group. The brain's soluble amyloid-beta 1-42 (Aβ42) of the water group was significantly higher than that of the diet group at the levels of 6 and 15 ppm. In conclusion, copper in the water group significantly increased the soluble Aβ42 in the brain and the 'free' copper in the serum, decreased the growth rate and hepatic GSH/SOD activity. The research studies carried out suggest that the copper in water is more 'toxic' than copper in diet and may increase the risk of Alzheimer's disease (AD).

Rate and Regulation of Copper Transport by Human Copper Transporter 1 (hCTR1)*

PubMed Central

Maryon, Edward B.; Molloy, Shannon A.; Ivy, Kristin; Yu, Huijun; Kaplan, Jack H.

2013-01-01

Human copper transporter 1 (hCTR1) is a homotrimer of a 190-amino acid monomer having three transmembrane domains believed to form a pore for copper permeation through the plasma membrane. The hCTR1-mediated copper transport mechanism is not well understood, nor has any measurement been made of the rate at which copper ions are transported by hCTR1. In this study, we estimated the rate of copper transport by the hCTR1 trimer in cultured cells using 64Cu uptake assays and quantification of plasma membrane hCTR1. For endogenous hCTR1, we estimated a turnover number of about 10 ions/trimer/s. When overexpressed in HEK293 cells, a second transmembrane domain mutant of hCTR1 (H139R) had a 3-fold higher Km value and a 4-fold higher turnover number than WT. Truncations of the intracellular C-terminal tail and an AAA substitution of the putative metal-binding HCH C-terminal tripeptide (thought to be required for transport) also exhibited elevated transport rates and Km values when compared with WT hCTR1. Unlike WT hCTR1, H139R and the C-terminal mutants did not undergo regulatory endocytosis in elevated copper. hCTR1 mutants combining methionine substitutions that block transport (M150L,M154L) on the extracellular side of the pore and the high transport H139R or AAA intracellular side mutations exhibited the blocked transport of M150L,M154L, confirming that Cu+ first interacts with the methionines during permeation. Our results show that hCTR1 elements on the intracellular side of the hCTR1 pore, including the carboxyl tail, are not essential for permeation, but serve to regulate the rate of copper entry. PMID:23658018

The Menkes and Wilson disease genes counteract in copper toxicosis in Labrador retrievers: a new canine model for copper-metabolism disorders

PubMed Central

Fieten, Hille; Gill, Yadvinder; Martin, Alan J.; Concilli, Mafalda; Dirksen, Karen; van Steenbeek, Frank G.; Spee, Bart; van den Ingh, Ted S. G. A. M.; Martens, Ellen C. C. P.; Festa, Paola; Chesi, Giancarlo; van de Sluis, Bart; Houwen, Roderick H. J. H.; Watson, Adrian L.; Aulchenko, Yurii S.; Hodgkinson, Victoria L.; Zhu, Sha; Petris, Michael J.; Polishchuk, Roman S.; Leegwater, Peter A. J.; Rothuizen, Jan

2016-01-01

ABSTRACT The deleterious effects of a disrupted copper metabolism are illustrated by hereditary diseases caused by mutations in the genes coding for the copper transporters ATP7A and ATP7B. Menkes disease, involving ATP7A, is a fatal neurodegenerative disorder of copper deficiency. Mutations in ATP7B lead to Wilson disease, which is characterized by a predominantly hepatic copper accumulation. The low incidence and the phenotypic variability of human copper toxicosis hamper identification of causal genes or modifier genes involved in the disease pathogenesis. The Labrador retriever was recently characterized as a new canine model for copper toxicosis. Purebred dogs have reduced genetic variability, which facilitates identification of genes involved in complex heritable traits that might influence phenotype in both humans and dogs. We performed a genome-wide association study in 235 Labrador retrievers and identified two chromosome regions containing ATP7A and ATP7B that were associated with variation in hepatic copper levels. DNA sequence analysis identified missense mutations in each gene. The amino acid substitution ATP7B:p.Arg1453Gln was associated with copper accumulation, whereas the amino acid substitution ATP7A:p.Thr327Ile partly protected against copper accumulation. Confocal microscopy indicated that aberrant copper metabolism upon expression of the ATP7B variant occurred because of mis-localization of the protein in the endoplasmic reticulum. Dermal fibroblasts derived from ATP7A:p.Thr327Ile dogs showed copper accumulation and delayed excretion. We identified the Labrador retriever as the first natural, non-rodent model for ATP7B-associated copper toxicosis. Attenuation of copper accumulation by the ATP7A mutation sheds an interesting light on the interplay of copper transporters in body copper homeostasis and warrants a thorough investigation of ATP7A as a modifier gene in copper-metabolism disorders. The identification of two new functional variants in

Redox control of copper homeostasis in cyanobacteria.

PubMed

López-Maury, Luis; Giner-Lamia, Joaquín; Florencio, Francisco J

2012-12-01

Copper is essential for all living organisms but is toxic when present in excess. Therefore organisms have developed homeostatic mechanism to tightly regulate its cellular concentration. In a recent study we have shown that CopRS two-component system is essential for copper resistance in the cyanobacterium Synechocystis sp PCC 6803. This two-component regulates expression of a heavy-metal RND type copper efflux system (encoded by copBAC) as well as its own expression (in the copMRS operon) in response to an excess of copper in the media. We have also observed that both operons are induced under condition that reduces the photosynthetic electron flow and this induction depends on the presence of the copper-protein, plastocyanin. These findings, together with CopS localization to the thylakoid membrane and its periplasmic domain being able to bind copper directly, suggest that CopS could be involved in copper detection in both the periplasm and the thylakoid lumen.

Copper-free route to triazole-modified peptidomimetic by the combination of two multicomponent reactions in one pot.

PubMed

Niu, Teng-fei; Gu, Lin; Yi, Wen-bin; Cai, Chun

2012-05-14

An efficient copper-free protocol for the synthesis of 5-methyl-1H-1,2,3-triazole-modified peptidomimetics through the combination of Ugi four-component reaction with a three-component cycloaddition, has been developed. The copper-free straightforward process is suitable for drug discovery. The chemoselective preparation of 1,4-disubstituted, triazole-modified peptidomimetics by using alkynyl substituted amines may have potential biological and synthetic application. At last, a "Lapinski type" analysis of the physical properties was performed, which is expected to help drug discovery.

CopM is a novel copper-binding protein involved in copper resistance in Synechocystis sp. PCC 6803.

PubMed

Giner-Lamia, Joaquín; López-Maury, Luis; Florencio, Francisco J

2015-02-01

Copper resistance system in the cyanobacterium Synechocystis sp. PCC 6803 comprises two operons, copMRS and copBAC, which are expressed in response to copper in the media. copBAC codes for a heavy-metal efflux-resistance nodulation and division (HME-RND) system, while copMRS codes for a protein of unknown function, CopM, and a two-component system CopRS, which controls the expression of these two operons. Here, we report that CopM is a periplasmic protein able to bind Cu(I) with high affinity (KD ~3 × 10(-16) ). Mutants lacking copM showed a sensitive copper phenotype similar to mutants affected in copB, but lower than mutants of the two-component system CopRS, suggesting that CopBAC and CopM constitute two independent resistance mechanisms. Moreover, constitutive expression of copM is able to partially suppress the copper sensitivity of the copR mutant strain, pointing out that CopM per se is able to confer copper resistance. Furthermore, constitutive expression of copM was able to reduce total cellular copper content of the copR mutant to the levels determined in the wild-type (WT) strain. Finally, CopM was localized not only in the periplasm but also in the extracellular space, suggesting that CopM can also prevent copper accumulation probably by direct copper binding outside the cell. © 2014 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

CopM is a novel copper-binding protein involved in copper resistance in Synechocystis sp. PCC 6803

PubMed Central

Giner-Lamia, Joaquín; López-Maury, Luis; Florencio, Francisco J

2015-01-01

Copper resistance system in the cyanobacterium Synechocystis sp. PCC 6803 comprises two operons, copMRS and copBAC, which are expressed in response to copper in the media. copBAC codes for a heavy-metal efflux–resistance nodulation and division (HME-RND) system, while copMRS codes for a protein of unknown function, CopM, and a two-component system CopRS, which controls the expression of these two operons. Here, we report that CopM is a periplasmic protein able to bind Cu(I) with high affinity (KD ∼3 × 10−16). Mutants lacking copM showed a sensitive copper phenotype similar to mutants affected in copB, but lower than mutants of the two-component system CopRS, suggesting that CopBAC and CopM constitute two independent resistance mechanisms. Moreover, constitutive expression of copM is able to partially suppress the copper sensitivity of the copR mutant strain, pointing out that CopM per se is able to confer copper resistance. Furthermore, constitutive expression of copM was able to reduce total cellular copper content of the copR mutant to the levels determined in the wild-type (WT) strain. Finally, CopM was localized not only in the periplasm but also in the extracellular space, suggesting that CopM can also prevent copper accumulation probably by direct copper binding outside the cell. PMID:25545960

Isolation of copper-binding proteins from activated sludge culture.

PubMed

Fukushi, K; Kato, S; Antsuki, T; Omura, T

2001-01-01

Six copper-binding microbial proteins were isolated from activated sludge cultures grown on media containing copper at various concentrations. Molecular weights among isolated proteins were ranged from 1.3k to 1 74k dalton. Isolated proteins were compared for their copper binding capabilities. Proteins isolated from cultures grown in the presence of copper in the growth media exhibited higher copper binding capabilities than those isolated from the culture grown in the absence of copper. The highest metal uptake of 61.23 (mol copper/mol protein) was observed by a protein isolated from a culture grown with copper at a concentration of 0.25 mM. This isolated protein (CBP2) had a molecular weight of 24k dalton. Other protein exhibited copper binding capability of 4.8-32.5 (mol copper/mol protein).

Characterization of the role of copCD in copper uptake and the 'copper-switch' in Methylosinus trichosporium OB3b.

PubMed

Gu, Wenyu; Farhan Ul Haque, Muhammad; Semrau, Jeremy D

2017-05-01

Methanotrophs or methane-oxidizing bacteria exhibit a unique 'copper-switch' where expression of two forms of methane monooxygenase (MMO) is controlled by the availability of copper. In the absence of copper, a cytoplasmic or soluble methane monooxygenase (sMMO) is expressed. In the presence of copper, a membrane-bound or particulate methane monooxygenase (pMMO) is expressed. These two forms of MMO have very different properties, and elucidation of the basis of the copper-switch is of significant interest as methanotrophs are becoming increasingly popular for the valorization of methane. Recently, it was suggested via characterization of a mutant of Methylosinus trichosporium OB3b that expresses sMMO in the presence of copper (smmoC mutant) that the copper-switch may be based on copCD. These genes encode for a periplasmic copper-binding protein and an inner membrane protein, respectively, and are used by other bacteria for copper uptake. Specific knockouts of copCD in M. trichosporium OB3b wild type, however, show that these genes are not part of the copper-switch in methanotrophs, nor do they appear to be critical for copper uptake. Rather, it appears that the constitutive expression of sMMO in the smmoC mutant of M. trichosporium OB3b may be due to multiple lesions as smmoC was generated via random chemical mutagenesis. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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.

21 CFR 524.463 - Copper naphthenate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Copper naphthenate. 524.463 Section 524.463 Food... DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.463 Copper naphthenate. (a) Amount. The drug is a 37.5 percent solution of copper naphthenate. (b) Sponsors. See Nos...

21 CFR 524.463 - Copper naphthenate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Copper naphthenate. 524.463 Section 524.463 Food... DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.463 Copper naphthenate. (a) Amount. The drug is a 37.5 percent solution of copper naphthenate. (b) Sponsors. See Nos...

Copper deficiency in the preterm infant of very low birthweight. Four cases and a reference range for plasma copper.

PubMed Central

Sutton, A M; Harvie, A; Cockburn, F; Farquharson, J; Logan, R W

1985-01-01

Four preterm infants of very low birthweight (less than 1500 g) developed signs of copper deficiency between age 8 and 10 weeks. All had required prolonged ventilatory support, parenteral nutrition, and nasojejunal feeding. The clinical features, which included osteoporosis, oedema, anaemia, neutropenia, and late apnoea improved when the oral copper intake was increased. Diagnosis was made more difficult because a suitable reference range for plasma copper was not available. Serial measurements of plasma copper in 39 preterm infants who had no important medical problems were used to produce a reference range for plasma copper from 30 weeks' gestation to term plus seven weeks. This information will aid recognition of hypocupraemia in the very low birthweight infant who is particularly at risk of copper deficiency. PMID:4026360

Copper Corrosion and Biocorrosion Events in Premise Plumbing

PubMed Central

Fischer, Diego A.; Alsina, Marco A.; Pastén, Pablo A.

2017-01-01

Corrosion of copper pipes may release high amounts of copper into the water, exceeding the maximum concentration of copper for drinking water standards. Typically, the events with the highest release of copper into drinking water are related to the presence of biofilms. This article reviews this phenomenon, focusing on copper ingestion and its health impacts, the physicochemical mechanisms and the microbial involvement on copper release, the techniques used to describe and understand this phenomenon, and the hydrodynamic effects. A conceptual model is proposed and the mathematical models are reviewed. PMID:28872628

Copper Corrosion and Biocorrosion Events in Premise Plumbing.

PubMed

Vargas, Ignacio T; Fischer, Diego A; Alsina, Marco A; Pavissich, Juan P; Pastén, Pablo A; Pizarro, Gonzalo E

2017-09-05

Corrosion of copper pipes may release high amounts of copper into the water, exceeding the maximum concentration of copper for drinking water standards. Typically, the events with the highest release of copper into drinking water are related to the presence of biofilms. This article reviews this phenomenon, focusing on copper ingestion and its health impacts, the physicochemical mechanisms and the microbial involvement on copper release, the techniques used to describe and understand this phenomenon, and the hydrodynamic effects. A conceptual model is proposed and the mathematical models are reviewed.

Surface investigation of naturally corroded gilded copper-based objects

NASA Astrophysics Data System (ADS)

Ingo, G. M.; Riccucci, C.; Lavorgna, M.; Salzano de Luna, M.; Pascucci, M.; Di Carlo, G.

2016-11-01

Gold and silver coated copper-based artefacts subjected to long-term natural corrosion phenomena were studied by means of the combined use of X-ray photoelectron spectroscopy (XPS), scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM + EDS), and optical microscopy (OM). The results allowed the identification of the chemistry and structure of the Au or Ag layers deposited by fire-gilding or mercury-silvering and the determination of the corrosion products formed due to interaction with the surrounding environment. Different degradation phenomena of the noble metal layer and copper substrate are induced by the presence of chlorine, sulphur and phosphorous and they are boosted by the metal galvanic coupling which makes gilded-metal art works unstable from a chemico-physical point of view. The SEM + EDS and OM results also suggest that particular care must be used during the removal of the encrustations and of the external corrosion products to avoid the loss of the remains of the noble layer often floating or embedded in the corrosion products. Furthermore, in order to avoid the reaction between nantokite (CuCl) and moisture the use no or low toxic inhibitors is suggested to avoid further severe degradation phenomena enhancing the long-lasting chemico-physical stability of these precious artefacts and giving them a greater chance of survival.

Use of Fatty Acid Methyl Ester Profiles to Compare Copper-Tolerant and Copper-Sensitive Strains of Pantoea ananatis.

PubMed

Nischwitz, C; Gitaitis, R; Sanders, H; Langston, D; Mullinix, B; Torrance, R; Boyhan, G; Zolobowska, L

2007-10-01

ABSTRACT A survey was conducted to evaluate differences in fatty acid methyl ester (FAME) profiles among strains of Pantoea ananatis, causal agent of center rot of onion (Allium cepa), isolated from 15 different onion cultivars in three different sites in Georgia. Differences in FAME composition were determined by plotting principal components (PCs) in two-dimensional plots. Euclidean distance squared (ED(2)) values indicated a high degree of similarity among strains. Plotting of PCs calculated from P. ananatis strains capable of growing on media amended with copper sulfate pentahydrate (200 mug/ml) indicated that copper-tolerant strains grouped into tight clusters separate from clusters formed by wild-type strains. However, unlike copper-sensitive strains, the copper-tolerant strains tended to cluster by location. A total of 80, 60, and 73% of the strains from Tift1, Tift2, and Tattnall, respectively, exhibited either confluent growth or partial growth on copper-amended medium. However, all strains were sensitive to a mixture of copper sulfate pentahydrate (200 mug/ml) and maneb (40 mug/ml). When copper-tolerant clones were analyzed and compared with their wild-type parents, in all cases the plotting of PCs developed from copper-tolerant clones formed tight clusters separate from clusters formed by the parents. Eigenvalues generated from these tests indicated that two components provided a good summary of the data, accounting for 98, 98, and 96% of the standardized variance for strains Pna 1-15B, Pna 1-12B, and Pna 2-5A, respectively. Furthermore, feature 4 (cis-9-hexadecenoic acid/2-hydroxy-13-methyltetradecanoic acid) and feature 7 (cis-9/trans-12/cis-7-octadecenoic acid) were the highest or second highest absolute values for PC1 in all three strains of the parents versus copper-tolerant clones, and hexadecanoic acid was the highest absolute value for PC2 in all three strains. Along with those fatty acids, dodecanoic acid and feature 3 (3-hydroxytetradecanoic

Effects of a copper-tolerant grass (Agrostis capillaris) on the ecosystem of a copper-contaminated arable soil

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

Boon, G.T.; Bouwman, L.A.; Bloem, J.

1998-10-01

To test how a dysfunctioning ecosystem of a severely metal-polluted soil responds to renewed plant growth, a pot experiment was conducted with soil from an experimental arable field with pH and copper gradients imposed 13 years ago. In this experiment, four pH/copper combinations from this field were either planted with a pH- and copper-resistant grass cultivar or remained fallow. During a 10-week period, the dynamics of the microbial activity and of the abundances of bacteria, protozoa. and nematodes were measured, as were the dynamics of several chemical soil parameters. After 13 years of copper, which had resulted in severely reducedmore » crop growth, no effects were observed on bacterial numbers, respiration, or protozoan numbers, but bacterial growth was strongly reduced in the low pH plots, and even more so in low pH plots enriched with copper. Of the organisms, only nematodes were negatively affected under conditions of high copper load at low pH. In these plots, numbers belonging to all feeding categories were strongly reduced. Planting of a copper-tolerant grass variety, Agrostis capillaris L. var. Parys Mountain, resulted within 10 weeks in faster bacterial growth and more protozoa and bacterivorous nematodes in comparison with fallow controls; these effects were markedly strongest in the acidic, copper-enriched soils. During incubation, fungivorous nematodes increased in all treatments, in fallow and in planted pots and in the pots with high-copper, low-pH soil. The results of this experiment suggest that introduction of plant growth is one of the major causes of increased biological activity in acidic contaminated soils. Planting such soils with metal-tolerant plant species can reestablish the necessary food base to support soil organism growth, and this can lead to numerous positive effects, reversing the loss of soil functions due to the high copper levels under acidic conditions.« less

Copper-Silicon Bronzes

DTIC Science & Technology

1933-05-11

copper alloys which have good static properties are disa:cinting in their endurance properties. The silicide allo~rs that are given high tensile strength...works satisfactorily, but the best welds 4 have been obtained by using a flux cdmposed of 905 fused borax and i0. sodium fluoride., The flux is...properties re- main almost the same. Grain size increases with sil- icon. III A study of hardening copper by heat treating its alloys with silicides

Copper-resistant bacteria reduces oxidative stress and uptake of copper in lentil plants: potential for bacterial bioremediation.

PubMed

Islam, Faisal; Yasmeen, Tahira; Ali, Qasim; Mubin, Muhammad; Ali, Shafaqat; Arif, Muhammad Saleem; Hussain, Sabir; Riaz, Muhammad; Abbas, Farhat

2016-01-01

For effective microbe-assisted bioremediation, metal-resistant plant growth-promoting bacteria (PGPB) must facilitate plant growth by restricting excess metal uptake in plants, leading to prevent its bio-amplification in the ecosystem. The aims of our study were to isolate and characterize copper (Cu)-resistant PGPB from waste water receiving contaminated soil. In addition, we investigated the phytotoxic effect of copper on the lentil plants inoculated with copper-resistant bacteria Providencia vermicola, grown in copper-contaminated soil. Copper-resistant P. vermicola showed multiple plant growth promoting characteristics, when used as a seed inoculant. It protected the lentil plants from copper toxicity with a considerable increase in root and shoot length, plant dry weight and leaf area. A notable increase in different gas exchange characteristics such as A, E, C i , g s , and A/E, as well as increase in N and P accumulation were also recorded in inoculated plants as compared to un-inoculated copper stressed plants. In addition, leaf chlorophyll content, root nodulation, number of pods, 1,000 seed weight were also higher in inoculated plants as compared with non-inoculated ones. Anti-oxidative defense mechanism improved significantly via elevated expression of reactive oxygen species -scavenging enzymes including ascorbate peroxidase, superoxide dismutase, catalase, and guaiacol peroxidase with alternate decrease in malondialdehyde and H2O2 contents, reduced electrolyte leakage, proline, and total phenolic contents suggesting that inoculation of P. vermicola triggered heavy metals stress-related defense pathways under copper stress. Overall, the results demonstrated that the P. vermicola seed inoculation confer heavy metal stress tolerance in lentil plant which can be used as a potent biotechnological tool to cope with the problems of copper pollution in crop plants for better yield.

Selection of Fecal Enterococci Exhibiting tcrB-Mediated Copper Resistance in Pigs Fed Diets Supplemented with Copper † ▿

PubMed Central

Amachawadi, R. G.; Shelton, N. W.; Shi, X.; Vinasco, J.; Dritz, S. S.; Tokach, M. D.; Nelssen, J. L.; Scott, H. M.; Nagaraja, T. G.

2011-01-01

Copper, as copper sulfate, is increasingly used as an alternative to in-feed antibiotics for growth promotion in weaned piglets. Acquired copper resistance, conferred by a plasmid-borne, transferable copper resistance (tcrB) gene, has been reported in Enterococcus faecium and E. faecalis. A longitudinal field study was undertaken to determine the relationship between copper supplementation and the prevalence of tcrB-positive enterococci in piglets. The study was done with weaned piglets, housed in 10 pens with 6 piglets per pen, fed diets supplemented with a normal (16.5 ppm; control) or an elevated (125 ppm) level of copper. Fecal samples were randomly collected from three piglets per pen on days 0, 14, 28, and 42 and plated on M-Enterococcus agar, and three enterococcal isolates were obtained from each sample. The overall prevalence of tcrB-positive enterococci was 21.1% (38/180) in piglets fed elevated copper and 2.8% (5/180) in the control. Among the 43 tcrB-positive isolates, 35 were E. faecium and 8 were E. faecalis. The mean MICs of copper for tcrB-negative and tcrB-positive enterococci were 6.2 and 22.2 mM, respectively. The restriction digestion of the genomic DNA of E. faecium or E. faecalis with S1 nuclease yielded a band of ∼194-kbp size to which both tcrB and the erm(B) gene probes hybridized. A conjugation assay demonstrated cotransfer of tcrB and erm(B) genes between E. faecium and E. faecalis strains. The higher prevalence of tcrB-positive enterococci in piglets fed elevated copper compared to that in piglets fed normal copper suggests that supplementation of copper in swine diets selected for resistance. PMID:21705534

Spatial Pattern of Copper Phosphate Precipitation Involves in Copper Accumulation and Resistance of Unsaturated Pseudomonas putida CZ1 Biofilm.

PubMed

Chen, Guangcun; Lin, Huirong; Chen, Xincai

2016-12-28

Bacterial biofilms are spatially structured communities that contain bacterial cells with a wide range of physiological states. The spatial distribution and speciation of copper in unsaturated Pseudomonas putida CZ1 biofilms that accumulated 147.0 mg copper per g dry weight were determined by transmission electron microscopy coupled with energy dispersive X-ray analysis, and micro-X-ray fluorescence microscopy coupled with micro-X-ray absorption near edge structure (micro-XANES) analysis. It was found that copper was mainly precipitated in a 75 μm thick layer as copper phosphate in the middle of the biofilm, while there were two living cell layers in the air-biofilm and biofilm-medium interfaces, respectively, distinguished from the copper precipitation layer by two interfaces. The X-ray absorption fine structure analysis of biofilm revealed that species resembling Cu₃(PO₄)₂ predominated in biofilm, followed by Cu-Citrate- and Cu-Glutathione-like species. Further analysis by micro-XANES revealed that 94.4% of copper were Cu₃(PO₄)₂-like species in the layer next to the air interface, whereas the copper species of the layer next to the medium interface were composed by 75.4% Cu₃(PO₄)₂, 10.9% Cu-Citrate-like species, and 11.2% Cu-Glutathione-like species. Thereby, it was suggested that copper was initially acquired by cells in the biofilm-air interface as a citrate complex, and then transported out and bound by out membranes of cells, released from the copper-bound membranes, and finally precipitated with phosphate in the extracellular matrix of the biofilm. These results revealed a clear spatial pattern of copper precipitation in unsaturated biofilm, which was responsible for the high copper tolerance and accumulation of the biofilm.

"Bulk" Nanocrystalline Metals: Review of the Current State of the Art and Future Opportunities for Copper and Copper Alloys

NASA Astrophysics Data System (ADS)

Tschopp, M. A.; Murdoch, H. A.; Kecskes, L. J.; Darling, K. A.

2014-06-01

It is a new beginning for innovative fundamental and applied science in nanocrystalline materials. Many of the processing and consolidation challenges that have haunted nanocrystalline materials are now more fully understood, opening the doors for bulk nanocrystalline materials and parts to be produced. While challenges remain, recent advances in experimental, computational, and theoretical capability have allowed for bulk specimens that have heretofore been pursued only on a limited basis. This article discusses the methodology for synthesis and consolidation of bulk nanocrystalline materials using mechanical alloying, the alloy development and synthesis process for stabilizing these materials at elevated temperatures, and the physical and mechanical properties of nanocrystalline materials with a focus throughout on nanocrystalline copper and a nanocrystalline Cu-Ta system, consolidated via equal channel angular extrusion, with properties rivaling that of nanocrystalline pure Ta. Moreover, modeling and simulation approaches as well as experimental results for grain growth, grain boundary processes, and deformation mechanisms in nanocrystalline copper are briefly reviewed and discussed. Integrating experiments and computational materials science for synthesizing bulk nanocrystalline materials can bring about the next generation of ultrahigh strength materials for defense and energy applications.

In long-term bedridden elderly patients with dietary copper deficiency, biochemical markers of bone resorption are increased with copper supplementation during 12 weeks.

PubMed

Kawada, Etsuo; Moridaira, Kazuaki; Itoh, Katsuhiko; Hoshino, Ayami; Tamura, Jun'ichi; Morita, Toyoho

2006-01-01

Although the effect of copper on bone has been tested in animals and healthy subjects, no studies concerning the effect of copper supplementation on bone metabolism in patients with copper deficiency have been reported because of the rarity of these patients. This study was conducted to investigate the effect of copper supplementation on bone metabolism in copper-deficient patients. This study included 10 patients (83.7 +/- 8.3 years) with dietary copper deficiency under long-term bed rest for more than 12 months. They had their diets supplemented with copper sulfate (3 mg/day) over 12 weeks in addition to their diet of only one kind of enteral food with a low concentration of copper. Serum copper and ceruloplasmin, urinary deoxypyridinoline (DPD) and collagen-type 1 N-telopeptide (NTX) (biomarkers of bone resorption), serum osteocalcin (OC) and bone-specific alkaline phosphatase (Bone ALP) (biomarkers of bone formation) were analyzed at baseline, 4 and 12 weeks after copper supplementation. DPD and NTX excretion were significantly increased 4 weeks after copper supplementation (p = 0.009 and p = 0.013, respectively). Serum bone ALP and OC were not significantly changed 12 weeks after copper supplementation (p = 0.051 and p = 0.594). In patients with nutritional copper deficiency, bone resorption markers are increased with copper supplementation. Copyright (c) 2006 S. Karger AG, Basel.

Synthesis of Commercial Products from Copper Wire-Drawing Waste

NASA Astrophysics Data System (ADS)

Ayala, J.; Fernández, B.

2014-06-01

Copper powder and copper sulfate pentahydrate were obtained from copper wire-drawing scale. The hydrometallurgical recycling process proposed in this article yields a high-purity copper powder and analytical grade copper sulfate pentahydrate. In the first stage of this process, the copper is dissolved in sulfuric acid media via dismutation of the scale. In the second stage, copper sulfate pentahydrate is precipitated using ethanol. Effects such as pH, reaction times, stirring speed, initial copper concentration, and ethanol/solution volume ratio were studied during the precipitation from solution reaction. The proposed method is technically straightforward and provides efficient recovery of Cu from wire-drawing scale.

Als1 and Als3 regulate the intracellular uptake of copper ions when Candida albicans biofilms are exposed to metallic copper surfaces.

PubMed

Zheng, Sha; Chang, Wenqiang; Li, Chen; Lou, Hongxiang

2016-05-01

Copper surfaces possess efficient antimicrobial effect. Here, we reported that copper surfaces could inactivate Candida albicans biofilms within 40 min. The intracellular reactive oxygen species in C. albicans biofilms were immediately stimulated during the contact of copper surfaces, which might be an important factor for killing the mature biofilms. Copper release assay demonstrated that the copper ions automatically released from the surface of 1 mm thick copper coupons with over 99.9% purity are not the key determinant for the copper-mediated killing action. The susceptibility test to copper surfaces by using C. albicans mutant strains, which were involved in efflux pumps, adhesins, biofilms formation or osmotic stress response showed that als1/als1 and als3/als3 displayed higher resistance to the copper surface contact than other mutants did. The intracellular concentration of copper ions was lower in als1/als1 and als3/als3 than that in wild-type strain. Transcriptional analysis revealed that the expression of copper transporter-related gene, CRP1, was significantly increased in als1/als1, als3/als3, suggesting a potential role of ALS1 and ALS3 in absorbing ions by regulating the expression of CRP1 This study provides a potential application in treating pathogenic fungi by using copper surfaces and uncovers the roles of ALS1 and ALS3 in absorbing copper ions for C. albicans. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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.

An Investigation of the Aerodynamic Characteristics of an 0.08-Scale Model of the Chance Vought XF7U-1 Airplane in the Langley High-Speed 7- by 10-Foot Tunnel. Part I - Basic Longitudinal Stability Characteristics, TED No. NACA DE308. Part 1; Basic Longitudinal Stability Characteristics, TED No. NACA DE308

NASA Technical Reports Server (NTRS)

Kemp, William B., Jr.; Kuhn, Richard E.; Goodson, Kenneth W.

1947-01-01

The stability and control characteristics of an 0.08-scale model of the Chance Vought XF7U-1 airplane have been investigated over a Mach number range from 0.40 to 0.91. Results of the basic longitudinal tests of the complete model with undeflected control surfaces are given in the present report with a very limited analysis of the results.

Assessing the release of copper from nanocopper-treated and conventional copper-treated lumber into marine waters I: Concentrations and rates.

PubMed

Parks, Ashley N; Cantwell, Mark G; Katz, David R; Cashman, Michaela A; Luxton, Todd P; Ho, Kay T; Burgess, Robert M

2018-03-25

Little is known about the release of metal engineered nanomaterials (ENMs) from consumer goods, including lumber treated with micronized copper. Micronized copper is a recent form of antifouling wood preservative containing nanosized copper particles for use in pressure-treated lumber. The present study investigated the concentrations released and the release rate of total copper over the course of 133 d under freshwater, estuarine, and marine salinity conditions (0, 1, 10, and 30‰) for several commercially available pressure-treated lumbers: micronized copper azole (MCA) at 0.96 and 2.4 kg/m 3 , alkaline copper quaternary (ACQ) at 0.30 and 9.6 kg/m 3 , and chromated copper arsenate (CCA) at 40 kg/m 3 . Lumber was tested as blocks and as sawdust. Overall, copper was released from all treated lumber samples. Under leaching conditions, total release ranged from 2 to 55% of the measured copper originally in the lumber, with release rate constants from the blocks of 0.03 to 2.71 (units per day). Generally, measured release and modeled equilibrium concentrations were significantly higher in the estuarine conditions compared with freshwater or marine salinities, whereas rate constants showed very limited differences between salinities. Furthermore, organic carbon was released during the leaching and demonstrated a significant relationship with released copper concentrations as a function of salinity. The results indicate that copper is released into estuarine/marine waters from multiple wood treatments including lumber amended with nanoparticle-sized copper. Environ Toxicol Chem 2018;9999:1-13. Published 2018 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America. Published 2018 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

An Investigation of the Aerodynamic Characteristics of an 0.08-Scale Model of the Chance Vought XF7U-1 Airplane in the Langley High-Speed 7- by 10-Foot Tunnel. Part IV - Aileron Characteristics TED No. NACA DE308. Part 4; Aileron Characteristics, TED No. NACA DE308

NASA Technical Reports Server (NTRS)

Goodson, Kenneth W.; Myers, Boyd C., II

1947-01-01

Tests have been conducted in the Langley high-speed 7- by 10-foot tunnel over a Mach number range from 0.40 to 0.91 to determine the stability and control characteristics of an 0.08-scale model of the Chance Vought XF7U-1 airplane. The aileron characteristics of the complete model are presented in the present report with a very limited analysis of the results.

Bioinorganic Chemical Modeling of Dioxygen-Activating Copper Proteins.

ERIC Educational Resources Information Center

Karlin, Kenneth D.; Gultneh, Yilma

1985-01-01

Discusses studies done in modeling the copper centers in the proteins hemocyanin (a dioxygen carrier), tyrosinase, and dopamine beta-hydroxylase. Copper proteins, model approach in copper bioinorganic chemistry, characterization of reversible oxygen carriers and dioxygen-metal complexes, a copper mono-oxygenase model reaction, and other topics are…

Comparison of copper heptonate with copper oxide wire particles as copper supplements for sheep on pasture of high molybdenum content.

PubMed

Judson, G J; Babidge, P J

2002-10-01

To assess the effectiveness of intramuscular injection of copper heptonate (CuHep) and an oral dose of copper oxide wire particles (COWP) in preventing Cu inadequacy in adult and young sheep on pasture of high Mo content. Field experiments with flocks of mature Merino wethers and crossbred weaners. Adult wethers were given 25 or 37.5 mg Cu as CuHep, 2.5 g COWP or no Cu treatment. The weaners were given 12.5 or 25 mg Cu as CuHep, 1.25 g COWP or no Cu treatment. At intervals over the next 12 (adults) or 8 (weaners) months the sheep were weighed and samples of blood and liver were collected for trace element assay. Wool samples collected from the adults at the end of the experiment were assessed for physical characteristics. The higher dosage of CuHep raised liver Cu above control group values for at least 9 months in adults and 3 months in weaners. The lower dosage of CuHep was similarly effective for 3 months in adults but was without effect in weaners. In adults the response to COWP matched that to the higher dosage of CuHep; in weaners it was greater, lasting at least 5 months. No changes indicative of Cu deficiency, apart from a depressed body weight in adults, were seen. In sheep on pasture of high Mo content a single intramuscular injection of CuHep providing 37.5 mg Cu to adults or 25 mg Cu to weaners will raise liver Cu reserves for at least 9 and 3 months respectively and may be an acceptable alternative to COWP for preventing seasonal Cu deficiency in sheep in southern Australia.

Method for providing uranium with a protective copper coating

DOEpatents

Waldrop, Forrest B.; Jones, Edward

1981-01-01

The present invention is directed to a method for providing uranium metal with a protective coating of copper. Uranium metal is subjected to a conventional cleaning operation wherein oxides and other surface contaminants are removed, followed by etching and pickling operations. The copper coating is provided by first electrodepositing a thin and relatively porous flash layer of copper on the uranium in a copper cyanide bath. The resulting copper-layered article is then heated in an air or inert atmosphere to volatilize and drive off the volatile material underlying the copper flash layer. After the heating step an adherent and essentially non-porous layer of copper is electro-deposited on the flash layer of copper to provide an adherent, multi-layer copper coating which is essentially impervious to corrosion by most gases.

Textured carbon surfaces on copper by sputtering

NASA Technical Reports Server (NTRS)

Curren, A. N. (Inventor); Jensen, K. A. (Inventor); Roman, R. F. (Inventor)

1986-01-01

A very thin layer of highly textured carbon is applied to a copper surface by a triode sputtering process. A carbon target and a copper substrate are simultaneously exposed to an argon plasma in a vacuum chamber. The resulting carbon surface is characterized by a dense, random array of needle like spires or peaks which extend perpendicularly from the copper surface. The coated copper is especially useful for electrode plates in multistage depressed collectors.

Porphyry copper deposit density

USGS Publications Warehouse

Singer, Donald A.; Berger, Vladimir; Menzie, W. David; Berger, Byron R.

2005-01-01

Estimating numbers of undiscovered mineral deposits has been a source of unease among economic geologists yet is a fundamental task in considering future supplies of resources. Estimates can be based on frequencies of deposits per unit of permissive area in control areas around the world in the same way that grade and tonnage frequencies are models of sizes and qualities of undiscovered deposits. To prevent biased estimates it is critical that, for a particular deposit type, these deposit density models be internally consistent with descriptive and grade and tonnage models of the same type. In this analysis only deposits and prospects that are likely to be included in future grade and tonnage models are employed, and deposits that have mineralization or alteration separated by less than an arbitrary but consistent distance—2 km for porphyry copper deposits—are combined into one deposit. Only 286 deposits and prospects that have more than half of the deposit not covered by postmineral rocks, sediments, or ice were counted.Nineteen control areas were selected and outlined along borders of hosting magmatic arc terranes based on three main features: (1) extensive exploration for porphyry copper deposits, (2) definable geologic settings of the porphyry copper deposits in island and continental volcanic-arc subduction-boundary zones, and (3) diversity of epochs of porphyry copper deposit formation.Porphyry copper deposit densities vary from 2 to 128 deposits per 100,000 km2 of exposed permissive rock, and the density histogram is skewed to high values. Ninety percent of the control areas have densities of four or more deposits, 50 percent have densities of 15 or more deposits, and 10 percent have densities of 35 or more deposits per 100,000 km2. Deposit density is not related to age or depth of emplacement. Porphyry copper deposit density is inversely related to the exposed area of permissive rock. The linear regression line and confidence limits constructed with

Evidence for the role of copper in the injury process of coliform bacteria in drinking water. [Escherichia coli

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

Domek, M.J.; LeChevallier, M.W.; Cameron, S.C.

1984-08-01

Low levels of copper in chlorine-free distribution water caused injury of coliform populations. Monitoring of 44 drinking water samples indicated that 64% of the coliform population was injured. Physical and chemical parameters were measured, including three heavy metals (Cu, Cd, and Pb). Copper concentrations were important, ranging from 0.007 to 0.54 mg/liter. Statistical analyses of these factors were used to develop a model to predict coliform injury. The model predicted almost 90% injury with a copper concentration near the mean observed value (0.158 mg/liter) in distribution waters. Laboratory studies with copper concentrations of 0.025 and 0.050 mg/liter in an inorganicmore » carbon buffer under controlled conditions of temperature and pH caused over 90% injury within 6 and 2 days, respectively. Studies of the metabolism of injured Escherichia coli cells indicated that the respiratory chain is at least one site of damage in injured cells.« less

Ligand-Doped Copper Oxo-hydroxide Nanoparticles are Effective Antimicrobials

NASA Astrophysics Data System (ADS)

Bastos, Carlos A. P.; Faria, Nuno; Ivask, Angela; Bondarenko, Olesja M.; Kahru, Anne; Powell, Jonathan

2018-04-01

Bacterial resistance to antimicrobial therapies is an increasing clinical problem. This is as true for topical applications as it is for systemic therapy. Topically, copper ions may be effective and cheap antimicrobials that act through multiple pathways thereby limiting opportunities to bacteria for resistance. However, the chemistry of copper does not lend itself to facile formulations that will readily release copper ions at biologically compatible pHs. Here, we have developed nanoparticulate copper hydroxide adipate tartrate (CHAT) as a cheap, safe, and readily synthesised material that should enable antimicrobial copper ion release in an infected wound environment. First, we synthesised CHAT and showed that this had disperse aquated particle sizes of 2-5 nm and a mean zeta potential of - 40 mV. Next, when diluted into bacterial medium, CHAT demonstrated similar efficacy to copper chloride against Escherichia coli and Staphylococcus aureus, with dose-dependent activity occurring mostly around 12.5-50 mg/L of copper. Indeed, at these levels, CHAT very rapidly dissolved and, as confirmed by a bacterial copper biosensor, showed identical intracellular loading to copper ions derived from copper chloride. However, when formulated at 250 mg/L in a topically applied matrix, namely hydroxyethyl cellulose, the benefit of CHAT over copper chloride was apparent. The former yielded rapid sustained release of copper within the bactericidal range, but the copper chloride, which formed insoluble precipitates at such concentration and pH, achieved a maximum release of 10 ± 7 mg/L copper by 24 h. We provide a practical formulation for topical copper-based antimicrobial therapy. Further studies, especially in vivo, are merited.

Bioavailable copper modulates oxidative phosphorylation and growth of tumors

PubMed Central

Ishida, Seiko; Andreux, Pénélope; Poitry-Yamate, Carole; Auwerx, Johan; Hanahan, Douglas

2013-01-01

Copper is an essential trace element, the imbalances of which are associated with various pathological conditions, including cancer, albeit via largely undefined molecular and cellular mechanisms. Here we provide evidence that levels of bioavailable copper modulate tumor growth. Chronic exposure to elevated levels of copper in drinking water, corresponding to the maximum allowed in public water supplies, stimulated proliferation of cancer cells and de novo pancreatic tumor growth in mice. Conversely, reducing systemic copper levels with a chelating drug, clinically used to treat copper disorders, impaired both. Under such copper limitation, tumors displayed decreased activity of the copper-binding mitochondrial enzyme cytochrome c oxidase and reduced ATP levels, despite enhanced glycolysis, which was not accompanied by increased invasiveness of tumors. The antiproliferative effect of copper chelation was enhanced when combined with inhibitors of glycolysis. Interestingly, larger tumors contained less copper than smaller tumors and exhibited comparatively lower activity of cytochrome c oxidase and increased glucose uptake. These results establish copper as a tumor promoter and reveal that varying levels of copper serves to regulate oxidative phosphorylation in rapidly proliferating cancer cells inside solid tumors. Thus, activation of glycolysis in tumors may in part reflect insufficient copper bioavailability in the tumor microenvironment. PMID:24218578

THE EVOLUTION OF SYNTHETICALLY PRECIPITATED COPPER SOLIDS

EPA Science Inventory

The objective of this study was to explore the effect of water quality, particularly chloride and sulfate, on copper mineral formation. Copper-sulfate and chloride compounds are often found on the surface of copper pipes in drinking water distribution systems. When attempting to ...

Laboratory evolution of copper tolerant yeast strains

PubMed Central

2012-01-01

Background Yeast strains endowed with robustness towards copper and/or enriched in intracellular Cu might find application in biotechnology processes, among others in the production of functional foods. Moreover, they can contribute to the study of human diseases related to impairments of copper metabolism. In this study, we investigated the molecular and physiological factors that confer copper tolerance to strains of baker's yeasts. Results We characterized the effects elicited in natural strains of Candida humilis and Saccharomyces cerevisiae by the exposure to copper in the culture broth. We observed that, whereas the growth of Saccharomyces cells was inhibited already at low Cu concentration, C. humilis was naturally robust and tolerated up to 1 g · L-1 CuSO4 in the medium. This resistant strain accumulated over 7 mg of Cu per gram of biomass and escaped severe oxidative stress thanks to high constitutive levels of superoxide dismutase and catalase. Both yeasts were then "evolved" to obtain hyper-resistant cells able to proliferate in high copper medium. While in S. cerevisiae the evolution of robustness towards Cu was paralleled by the increase of antioxidative enzymes, these same activities decreased in evolved hyper-resistant Candida cells. We also characterized in some detail changes in the profile of copper binding proteins, that appeared to be modified by evolution but, again, in a different way in the two yeasts. Conclusions Following evolution, both Candida and Saccharomyces cells were able to proliferate up to 2.5 g · L-1 CuSO4 and to accumulate high amounts of intracellular copper. The comparison of yeasts differing in their robustness, allowed highlighting physiological and molecular determinants of natural and acquired copper tolerance. We observed that different mechanisms contribute to confer metal tolerance: the control of copper uptake, changes in the levels of enzymes involved in oxidative stress response and changes in the copper

A copper-induced quinone degradation pathway provides protection against combined copper/quinone stress in Lactococcus lactis IL1403.

PubMed

Mancini, Stefano; Abicht, Helge K; Gonskikh, Yulia; Solioz, Marc

2015-02-01

Quinones are ubiquitous in the environment. They occur naturally but are also in widespread use in human and industrial activities. Quinones alone are relatively benign to bacteria, but in combination with copper, they become toxic by a mechanism that leads to intracellular thiol depletion. Here, it was shown that the yahCD-yaiAB operon of Lactococcus lactis IL1403 provides resistance to combined copper/quinone stress. The operon is under the control of CopR, which also regulates expression of the copRZA copper resistance operon as well as other L. lactis genes. Expression of the yahCD-yaiAB operon is induced by copper but not by quinones. Two of the proteins encoded by the operon appear to play key roles in alleviating quinone/copper stress: YaiB is a flavoprotein that converts p-benzoquinones to less toxic hydroquinones, using reduced nicotinamide adenine dinucleotide phosphate (NADPH) as reductant; YaiA is a hydroquinone dioxygenase that converts hydroquinone putatively to 4-hydroxymuconic semialdehyde in an oxygen-consuming reaction. Hydroquinone and methylhydroquinone are both substrates of YaiA. Deletion of yaiB causes increased sensitivity of L. lactis to quinones and complete growth arrest under combined quinone and copper stress. Copper induction of the yahCD-yaiAB operon offers protection to copper/quinone toxicity and could provide a growth advantage to L. lactis in some environments. © 2014 John Wiley & Sons Ltd.

Determination of factors responsible for the bioweathering of copper minerals from organic-rich copper-bearing Kupferschiefer black shale.

PubMed

Włodarczyk, Agnieszka; Szymańska, Agata; Skłodowska, Aleksandra; Matlakowska, Renata

2016-04-01

The aim of this study was to investigate the bioweathering of copper minerals present in the alkaline, copper-bearing and organic-rich Kupferschiefer black shale through the action of a consortium of indigenous lithobiontic, heterotrophic, neutrophilic bacteria isolated from this sedimentary rock. The involvement of microorganisms in the direct/enzymatic bioweathering of fossil organic matter of the rock was confirmed. As a result of bacterial activity, a spectrum of various organic compounds such as urea and phosphoric acid tributyl ester were released from the rock. These compounds indirectly act on the copper minerals occurring in the rock and cause them to weather. This process was reflected in the mobilization of copper, iron and sulfur and in changes in the appearance of copper minerals observed under reflected light. The potential role of identified enzymes in biodegradation of fossil organic matter and role of organic compounds released from black shale as a result of this process in copper minerals weathering was discussed. The presented results provide a new insight into the role of chemical compounds released by bacteria during fossil organic matter bioweathering potentially important in the cycling of copper and iron deposited in the sedimentary rock. The originality of the described phenomenon lies in the fact that the bioweathering of fossil organic matter and, consequently, of copper minerals occur simultaneously in the same environment, without any additional sources of energy, electrons and carbon. Copyright © 2016 Elsevier Ltd. All rights reserved.

Copper

Integrated Risk Information System (IRIS)

Copper ; CASRN 7440 - 50 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effects )

The association between serum copper concentrations and cardiovascular disease risk factors in children and adolescents in NHANES.

PubMed

Zang, Xiaodong; Huang, Hesuyuan; Zhuang, Zhulun; Chen, Runsen; Xie, Zongyun; Xu, Cheng; Mo, Xuming

2018-06-01

Copper is an essential element in human beings, alterations in serum copper levels could potentially have effect on human health. To date, no data are available regarding how serum copper affects cardiovascular disease (CVD) risk factors in children and adolescents. We examined the association between serum copper levels and CVD risk factors in children and adolescents. We analyzed data consisting of 1427 subjects from a nationally representative sample of the US population in the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2014. The CVD risk factors included total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, fasting glucose, glycohemoglobin, fasting insulin, and blood pressure. Multivariate and generalized linear regressions were performed to investigate associations adjusted for age, gender, ethnicity, poverty:income ratio (PIR), BMI, energy intake, and physical activity. We found significant associations between serum copper and total cholesterol (coefficient = 0.132; 95% CI 0.081, 0.182; P for trend < 0.001), glycohemoglobin (coefficient = 0.044; 95% CI 0.020, 0.069; P < 0.001), and fasting insulin (coefficient = 0.730; 95% CI 0.410, 1.050; P < 0.001) among the included participants. Moreover, in the generalized linear models, subjects with the highest copper levels demonstrated a 0.83% (95% CI 0.44%, 1.24%) greater increase in serum total cholesterol (p for trend < 0.001) when compared to participants with the lowest copper concentrations. Our results provide the first epidemiological evidence that serum copper concentrations are associated with total cholesterol concentrations in children and adolescents. However, the underlying mechanisms still need further exploration.

Sporicidal efficacy of thermal-sprayed copper alloy coating.

PubMed

Shafaghi, Romina; Mostaghimi, Javad; Pershin, Valerian; Ringuette, Maurice

2017-05-01

Approximately 200 000 Canadians acquire healthcare-associated bacterial infections each year and several-fold more acquire food-borne bacterial illnesses. Bacterial spores are particularly problematic because they can survive on surfaces for several months. Owing to its sporicidal activity, copper alloy sheet metal is sometimes used in hospital settings, but its widespread use is limited by cost and incompatibility with complex furniture and instrument designs and topographies. A potential alternative is the use of thermal spray technology to coat surfaces with copper alloys. We compared the sporicidal activity of thermally sprayed copper alloy on stainless steel with that of copper alloy sheet metal against Bacillus subtilis spores. Spores remained intact for at least 1 week on uncoated stainless steel, whereas spore fragmentation was initiated within 2 h of exposure to either copper surface. Less than 15% of spores were viable 2 h after exposure to either copper surface, as compared with stainless steel. By day 7, only degraded spores and petal-like nanoflowers were present on the copper surfaces. Nanoflowers, which are laminar arrangements of thin crystal sheets composed of carbon - copper phosphate, appeared to be derived from the degraded spores. Altogether, these results indicate that a thermal-sprayed copper alloy coating on stainless steel provides sporicidal activity similar to that afforded by copper alloy sheet metal.

Prediction of Thermal Fatigue in Tooling for Die-casting Copper via Finite Element Analysis

NASA Astrophysics Data System (ADS)

Sakhuja, Amit; Brevick, Jerald R.

2004-06-01

Recent research by the Copper Development Association (CDA) has demonstrated the feasibility of die-casting electric motor rotors using copper. Electric motors using copper rotors are significantly more energy efficient relative to motors using aluminum rotors. However, one of the challenges in copper rotor die-casting is low tool life. Experiments have shown that the higher molten metal temperature of copper (1085 °C), as compared to aluminum (660 °C) accelerates the onset of thermal fatigue or heat checking in traditional H-13 tool steel. This happens primarily because the mechanical properties of H-13 tool steel decrease significantly above 650 °C. Potential approaches to mitigate the heat checking problem include: 1) identification of potential tool materials having better high temperature mechanical properties than H-13, and 2) reduction of the magnitude of cyclic thermal excursions experienced by the tooling by increasing the bulk die temperature. A preliminary assessment of alternative tool materials has led to the selection of nickel-based alloys Haynes 230 and Inconel 617 as potential candidates. These alloys were selected based on their elevated temperature physical and mechanical properties. Therefore, the overall objective of this research work was to predict the number of copper rotor die-casting cycles to the onset of heat checking (tool life) as a function of bulk die temperature (up to 650 °C) for Haynes 230 and Inconel 617 alloys. To achieve these goals, a 2D thermo-mechanical FEA was performed to evaluate strain ranges on selected die surfaces. The method of Universal Slopes (Strain Life Method) was then employed for thermal fatigue life predictions.

Evaluation of Serum Levels of Zinc, Copper, Iron, and Zinc/Copper Ratio in Cutaneous Leishmaniasis

PubMed Central

Pourfallah, F; Javadian, S; Zamani, Z; Saghiri, R; Sadeghi, S; Zarea, B; Faiaz, Sh; Mirkhani, F; Fatemi, N

2009-01-01

Background: The purpose of this study was to evaluate the levels of zinc (Zn), copper (Cu), iron (Fe) and zinc/ copper ratio in the serum of patients with cutaneous leishmaniasis in Qom Province, center of Iran. Methods: Serum levels of zinc and copper were determined by flame atomic absorption spectrophotometer and serum iron concentration was measured by using an Auto Analyzer. The study group consisted of 60 patients with cutaneous leishmaniasis and the control group of 100 healthy volunteers from the same area who were not exposed to cutaneous leishmaniasis. Result: There were no statistically significant differences in age and body mass index between the two groups. Serum Zn (P< 0.001) and Fe (P< 0.05) levels were lower in patients with cutaneous leishmaniasis than the control group. We also found serum Cu concentration (P< 0.05) in the patient group was significantly higher than that of the control group. However, zinc/ copper ratio (P< 0.001) was lower in patients with cutaneous leishmaniasis than in the control group. Conclusion: Our data indicated that Zn/Cu ratio was significantly lower in patients with CL as compared to the controls. Earlier reports suggest that, this ratio imbalance could be a useful marker for immune dysfunction in leishmaniasis. There was also strong association of Zn, Cu and Fe with CL. It suggests the use of blood zinc, copper, iron concentration and the copper/zinc ratio (Zn/Cu), as a means for estimating the prognosis of CL. PMID:22808376

Why copper is preferred over iron for oxygen activation and reduction in haem-copper oxidases.

PubMed

Bhagi-Damodaran, Ambika; Michael, Matthew A; Zhu, Qianhong; Reed, Julian; Sandoval, Braddock A; Mirts, Evan N; Chakraborty, Saumen; Moënne-Loccoz, Pierre; Zhang, Yong; Lu, Yi

2017-03-01

Haem-copper oxidase (HCO) catalyses the natural reduction of oxygen to water using a haem-copper centre. Despite decades of research on HCOs, the role of non-haem metal and the reason for nature's choice of copper over other metals such as iron remains unclear. Here, we use a biosynthetic model of HCO in myoglobin that selectively binds different non-haem metals to demonstrate 30-fold and 11-fold enhancements in the oxidase activity of Cu- and Fe-bound HCO mimics, respectively, as compared with Zn-bound mimics. Detailed electrochemical, kinetic and vibrational spectroscopic studies, in tandem with theoretical density functional theory calculations, demonstrate that the non-haem metal not only donates electrons to oxygen but also activates it for efficient O-O bond cleavage. Furthermore, the higher redox potential of copper and the enhanced weakening of the O-O bond from the higher electron density in the d orbital of copper are central to its higher oxidase activity over iron. This work resolves a long-standing question in bioenergetics, and renders a chemical-biological basis for the design of future oxygen-reduction catalysts.

Testing the Underlying Chemical Principles of the Biotic Ligand Model (BLM) to Marine Copper Systems: Measuring Copper Speciation Using Fluorescence Quenching.

PubMed

Tait, Tara N; McGeer, James C; Smith, D Scott

2018-01-01

Speciation of copper in marine systems strongly influences the ability of copper to cause toxicity. Natural organic matter (NOM) contains many binding sites which provides a protective effect on copper toxicity. The purpose of this study was to characterize copper binding with NOM using fluorescence quenching techniques. Fluorescence quenching of NOM with copper was performed on nine sea water samples. The resulting stability constants and binding capacities were consistent with literature values of marine NOM, showing strong binding with [Formula: see text] values from 7.64 to 10.2 and binding capacities ranging from 15 to 3110 nmol mg [Formula: see text] Free copper concentrations estimated at total dissolved copper concentrations corresponding to previously published rotifer effect concentrations, in the same nine samples, were statistically the same as the range of free copper calculated for the effect concentration in NOM-free artificial seawater. These data confirms the applicability of fluorescence spectroscopy techniques for NOM and copper speciation characterization in sea water and demonstrates that such measured speciation is consistent with the chemical principles underlying the biotic ligand model approach for bioavailability-based metals risk assessment.

Construction of a high efficiency copper adsorption bacterial system via peptide display and its application on copper dye polluted wastewater.

PubMed

Maruthamuthu, Murali Kannan; Nadarajan, Saravanan Prabhu; Ganesh, Irisappan; Ravikumar, Sambandam; Yun, Hyungdon; Yoo, Ik-Keun; Hong, Soon Ho

2015-11-01

For the construction of an efficient copper waste treatment system, a cell surface display strategy was employed. The copper adsorption ability of recombinant bacterial strains displaying three different copper binding peptides were evaluated in LB Luria-Bertani medium (LB), artificial wastewater, and copper phthalocyanine containing textile dye industry wastewater samples. Structural characteristics of the three peptides were also analyzed by similarity-based structure modeling. The best binding peptide was chosen for the construction of a dimeric peptide display and the adsorption ability of the monomeric and dimeric peptide displayed strains were compared. The dimeric peptide displayed strain showed superior copper adsorption in all three tested conditions (LB, artificial wastewater, and textile dye industry wastewater). When the strains were exposed to copper phthalocyanine dye polluted wastewater, the dimeric peptide display [543.27 µmol/g DCW dry cell weight (DCW)] showed higher adsorption of copper when compared with the monomeric strains (243.53 µmol/g DCW).

Effect of copper doping sol-gel ZnO thin films: physical properties and sensitivity to ethanol vapor

NASA Astrophysics Data System (ADS)

Boukaous, Chahra; Benhaoua, Boubaker; Telia, Azzedine; Ghanem, Salah

2017-10-01

In the present paper, the effect of copper doping ZnO thin films, deposited using a sol-gel dip-coating technique, on the structural, optical and ethanol vapor-sensing properties, was investigated. The range of the doping content is 0 wt. %-5 wt. % Cu/Zn and the films’ properties were studied using x-ray diffraction, scanning electron microscopy and a UV-vis spectrophotometer. The obtained results indicated that undoped and copper-doped zinc oxide thin films have polycrystalline wurtzite structure with (1 0 1) preferred orientation. All samples have a smooth and dense structure free of pinholes. A decrease in the band gap with Cu concentration in the ZnO network was observed. The influence of the dopant on ethanol vapor-sensing properties shows an increase in the film sensitivity to the ethanol vapor within the Cu concentration.

Differential bacteriophage mortality on exposure to copper.

PubMed

Li, Jinyu; Dennehy, John J

2011-10-01

Many studies report that copper can be used to control microbial growth, including that of viruses. We determined the rates of copper-mediated inactivation for a wide range of bacteriophages. We used two methods to test the effect of copper on bacteriophage survival. One method involved placing small volumes of bacteriophage lysate on copper and stainless steel coupons. Following exposure, metal coupons were rinsed with lysogeny broth, and the resulting fluid was serially diluted and plated on agar with the corresponding bacterial host. The second method involved adding copper sulfate (CuSO(4)) to bacteriophage lysates to a final concentration of 5 mM. Aliquots were removed from the mixture, serially diluted, and plated with the appropriate bacterial host. Significant mortality was observed among the double-stranded RNA (dsRNA) bacteriophages Φ6 and Φ8, the single-stranded RNA (ssRNA) bacteriophage PP7, the ssDNA bacteriophage ΦX174, and the dsDNA bacteriophage PM2. However, the dsDNA bacteriophages PRD1, T4, and λ were relatively unaffected by copper. Interestingly, lipid-containing bacteriophages were most susceptible to copper toxicity. In addition, in the first experimental method, the pattern of bacteriophage Φ6 survival over time showed a plateau in mortality after lysates dried out. This finding suggests that copper's effect on bacteriophage is mediated by the presence of water.

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.

49 CFR 192.125 - Design of copper pipe.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Design of copper pipe. 192.125 Section 192.125... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Pipe Design § 192.125 Design of copper pipe. (a) Copper... hard drawn. (b) Copper pipe used in service lines must have wall thickness not less than that indicated...

Relationship among aqueous copper half-lives and responses of Pimephales promelas to a series of copper sulfate pentahydrate concentrations.

PubMed

Calomeni, Alyssa J; Kinley, Ciera M; Geer, Tyler D; Iwinski, Kyla J; Hendrikse, Maas; Rodgers, John H

2018-04-01

Copper algaecide exposures in situ are often of shorter duration than exposures for static toxicity experiments because aqueous concentrations in situ dissipate as a function of site-specific fate processes. Consequently, responses of organisms to static copper exposures may overestimate effects following in situ exposures. To understand the role of exposure duration for altering responses, Pimephales promelas survival was compared following static (96 h) and pulse (1.5, 4, 8, and 15 h half-lives) exposures of CuSO 4 •5H 2 O. Copper concentrations sorbed by fry indicated a consequence of different exposures. Responses of P. promelas to static exposures resulted in 96 h LC 50 s of 166 µgCu/L (95% confidence interval [CI], 142-189 µgCu/L) as soluble copper and 162 µgCu/L (CI, 140-183 µgCu/L) as acid soluble copper. Relative to static 96 h LC 50 s, exposures with half-lives of 1.5, 4 and 8 h resulted in LC 50 s 10, 3 and 2 times greater, respectively, for responses measured 96 h after exposure initiation. Copper concentrations extracted from fry exposed for 1.5, 4 and 8 h half-lives were less than the static experiment. However, copper sorbed by fry in the 15 h half-life experiment was not different than the static experiment. The relationship between 96 h LC 50 and 1/half-life was expressed using the equations y = 116 + 1360 × (R 2  = 0.97) for soluble copper and y = 147 + 1620 × (R 2  = 0.98) for acid soluble copper. Incorporation of exposure duration for predictions of P. promelas responses to copper pulse exposures increases prediction accuracy by an order of magnitude.

Serum zinc, copper, retinol-binding protein, prealbumin, and ceruloplasmin concentrations in infants receiving intravenous zinc and copper supplementation.

PubMed

Lockitch, G; Godolphin, W; Pendray, M R; Riddell, D; Quigley, G

1983-02-01

One hundred twenty-seven newborn infants requiring parenteral nutrition were randomly assigned to receive differing amounts of zinc (40 to 400 micrograms/kg/day) and copper (20 or 40 micrograms/kg/day) supplementation within five birth weight groups (600 to 2,500 gm). The serum zinc concentration remained relatively constant in the group receiving the most zinc supplementation after two weeks of therapy, but declined sharply in the groups receiving less supplementation. No effect of increased copper intake was noted on ceruloplasmin values, but a difference in serum copper concentrations was noted at two weeks. No correlation was noted between serum zinc and copper values or among those for serum zinc, retinol-binding protein, and prealbumin. Reference ranges were defined for serum zinc, copper, retinol-binding protein, prealbumin, and ceruloplasmin in the preterm infant.

[Biohydrometallurgical technology of a complex copper concentrate process].

PubMed

Murav'ev, M I; Fomchenko, N V; Kondrat'eva, T F

2011-01-01

Leaching of sulfide-oxidized copper concentrate of the Udokan deposit ore with a copper content of 37.4% was studied. In the course of treatment in a sulfuric acid solution with pH 1.2, a copper leaching rate was 6.9 g/kg h for 22 h, which allowed extraction of 40.6% of copper. As a result of subsequent chemical leaching at 80 degrees C during 7 h with a solution of sulphate ferric iron obtained after bio-oxidation by an association of microorganisms, the rate of copper recovery was 52.7 g/kg h. The total copper recovery was 94.5% (over 29 h). Regeneration of the Fe3+ ions was carried out by an association of moderately thermophilic microorganisms, including bacteria of genus Sulfobacillus and archaea of genus Ferroplasma acidiphilum, at 1.0 g/l h at 40 degrees C in the presence of 3% solids obtained by chemical leaching of copper concentrate. A technological scheme of a complex copper concentrate process with the use of bacterial-chemical leaching is proposed.

Copper Tolerance and Characterization of a Copper-Responsive Operon, copYAZ, in an M1T1 Clinical Strain of Streptococcus pyogenes

PubMed Central

Gordon, Lily D.; Fang, Zhong; Holder, Robert C.; Reid, Sean D.

2015-01-01

ABSTRACT Infection with Streptococcus pyogenes is associated with a breadth of clinical manifestations ranging from mild pharyngitis to severe necrotizing fasciitis. Elevated levels of intracellular copper are highly toxic to this bacterium, and thus, the microbe must tightly regulate the level of this metal ion by one or more mechanisms, which have, to date, not been clearly defined. In this study, we have identified two virulence mechanisms by which S. pyogenes protects itself against copper toxicity. We defined a set of putative genes, copY (for a regulator), copA (for a P1-type ATPase), and copZ (for a copper chaperone), whose expression is regulated by copper. Our results indicate that these genes are highly conserved among a range of clinical S. pyogenes isolates. The copY, copA, and copZ genes are induced by copper and are transcribed as a single unit. Heterologous expression assays revealed that S. pyogenes CopA can confer copper tolerance in a copper-sensitive Escherichia coli mutant by preventing the accumulation of toxic levels of copper, a finding that is consistent with a role for CopA in copper export. Evaluation of the effect of copper stress on S. pyogenes in a planktonic or biofilm state revealed that biofilms may aid in protection during initial exposure to copper. However, copper stress appears to prevent the shift from the planktonic to the biofilm state. Therefore, our results indicate that S. pyogenes may use several virulence mechanisms, including altered gene expression and a transition to and from planktonic and biofilm states, to promote survival during copper stress. IMPORTANCE Bacterial pathogens encounter multiple stressors at the host-pathogen interface. This study evaluates a virulence mechanism(s) utilized by S. pyogenes to combat copper at sites of infection. A better understanding of pathogen tolerance to stressors such as copper is necessary to determine how host-pathogen interactions impact bacterial survival during infections

Evaluation of biocidal efficacy of copper alloy coatings in comparison with solid metal surfaces: generation of organic copper phosphate nanoflowers.

PubMed

Gutierrez, H; Portman, T; Pershin, V; Ringuette, M

2013-03-01

To analyse the biocidal efficacy of thermal sprayed copper surfaces. Copper alloy sheet metals containing >60% copper have been shown to exhibit potent biocidal activity. Surface biocidal activity was assessed by epifluorescence microscopy. After 2-h exposure at 20 °C in phosphate-buffered saline (PBS), contact killing of Gram-negative Escherichia coli and Gram-positive Staphylococcus epidermidis by brass sheet metal and phosphor bronze was 3-4-times higher than that by stainless steel. SEM observations revealed that the surface membranes of both bacterial strains were slightly more irregular when exposed to brass sheet metal than stainless steel. However, when exposed to phosphor bronze coating, E. coli were 3-4 times larger with irregular membrane morphology. In addition, the majority of the cells were associated with spherical carbon-copper-phosphate crystalline nanostructures characteristic of nanoflowers. The membranes of many of the S. epidermidis exhibited blebbing, and a small subset was also associated with nanoflowers. Our data indicate that increasing the surface roughness of copper alloys had a pronounced impact on the membrane integrity of Gram-positive and, to a lesser degree, Gram-negative bacteria. In the presence of PBS, carbon-copper-phosphate-containing nanoflowers were formed, likely nucleated by components derived from killed bacteria. The intimate association of the bacteria with the nanoflowers and phosphor bronze coating likely contributed to their nonreversible adhesion. Thermal spraying of copper alloys provides a strategy for the rapid coating of three-dimensional organic and inorganic surfaces with biocidal copper alloys. Our study demonstrates that the macroscale surface roughness generated by the thermal spray process enhances the biocidal activity of copper alloys compared with the nanoscale surface roughness of copper sheet metals. Moreover, the coating surface topography provides conditions for the rapid formation of organic copper

EVALUATING THE IMPACT OF WATER CHEMISTRY ON CUPROSOLVENCY AND COPPER CORROSION BY-PRODUCT USING A SIMPLE COPPER PIPE RECIRCULATING LOOP SYSTEM

EPA Science Inventory

1991, EPA publicized the Lead and Copper Rule (LCR),which set regulations to minimize the amount of lead copper in drinking water. The LCR set the copper action level at 1.3 mg/L in more then 10% of customer’s first-draw taps sampled. Potential health effects of copper include vo...

49 CFR 192.377 - Service lines: Copper.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false Service lines: Copper. 192.377 Section 192.377 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... § 192.377 Service lines: Copper. Each copper service line installed within a building must be protected...

49 CFR 192.377 - Service lines: Copper.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Service lines: Copper. 192.377 Section 192.377 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... § 192.377 Service lines: Copper. Each copper service line installed within a building must be protected...

Copper toxicity in aquaculture: A practical approach

USDA-ARS?s Scientific Manuscript database

Copper sulfate is used as a therapeutant for various applications in aquaculture. There is a great deal of information on the toxicity of copper, especially in low-alkalinity waters; however, much of this information is fragmented, and a comprehensive guide of copper toxicity and safe concentration...

Divalent Copper as a Major Triggering Agent in Alzheimer's Disease.

PubMed

Brewer, George J

2015-01-01

Alzheimer's disease (AD) is at epidemic proportions in developed countries, with a steady increase in the early 1900 s, and then exploding over the last 50 years. This epidemiology points to something causative in the environment of developed countries. This paper will review the considerable evidence that that something could be inorganic copper ingestion. The epidemic parallels closely the spread of copper plumbing, with copper leached from the plumbing into drinking water being a main causal feature, aided by the increasingly common use of supplement pills containing copper. Inorganic copper is divalent copper, or copper-2, while we now know that organic copper, or copper in foods, is primarily monovalent copper, or copper-1. The intestinal transport system, Ctr1, absorbs copper-1 and the copper moves to the liver, where it is put into safe channels. Copper-2 is not absorbed by Ctr1, and some of it bypasses the liver and goes directly into the blood, where it appears to be exquisitely toxic to brain cognition. Thus, while aggregation of amyloid-β has been postulated to be the cause of AD under current dogma, the great increase in prevalence over the last century appears to be due to ingestion of copper-2, which may be causing the aggregation, and/or increasing the oxidant toxicity of the aggregates. An alternative hypothesis proposes that oxidant stress is the primary injuring agent, and under this hypothesis, copper-2 accumulation in the brain may be a causal factor of the oxidant injury. Thus, irrespective of which hypothesis is correct, AD can be classified, at least in part, as a copper-2 toxicity disease. It is relatively easy to avoid copper-2 ingestion, as discussed in this review. If most people begin avoiding copper-2 ingestion, perhaps the epidemic of this serious disease can be aborted.

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.

Water requirements of the copper industry

USGS Publications Warehouse

Mussey, Orville Durey

1961-01-01

The copper industry in 1955 used about 330 million gallons of water per day in the mining and manufacturing of primary copper. This amount is about 0.3 percent of the total estimated withdrawals of industrial water in the United States in 1955. These facts were determined by a survey, in 1956, of the amount and chemical quality of the water used by the copper industry. A large part of this water was used in Arizona, Nevada, New Mexico, and Utah, where about five-sixths of the domestic copper is mined. Much of the remaining water use was near New York City where most of the electrolytic refineries are located, and the rest of the water was used in widely scattered places. A little more than 100,000 gallons of water per ton of copper was used in the production of copper from domestic ores. Of this amount about 70,000 gallons per ton was used in mining and concentrating the ore, and about 30,000 gallons per ton was used to reduce the concentrate to refined copper. In areas where water was scarce or expensive, the unit water use was a little more than half the average. About 60 mgd (million gallons per day) or 18 percent of the water was used consumptively, and nearly all of the consumptive use occurred in the water-short areas of the West. Of the water used in mining and manufacturing primary copper 75 percent was surface water and 25 percent was ground water, 89 percent of this water was self-supplied by the copper companies and 11 percent came from public supplies. Much of the water used in producing primary copper was of comparatively poor quality; about 46 percent was saline containing 1,000 ppm (parts per million) or more of dissolved solids and 54 percent was fresh. Water that is used for concentration of copper ores by flotation or even any water that comes in contact with the ore at any time before it reaches the flotation plant must be free of petroleum products because they interfere with the flotation process. The water used in mining and ore concentration

Capable Copper Electrodeposition Process for Integrated Circuit - substrate Packaging Manufacturing

NASA Astrophysics Data System (ADS)

Ghanbari, Nasrin

This work demonstrates a capable reverse pulse deposition methodology to influence gap fill behavior inside microvia along with a uniform deposit in the fine line patterned regions for substrate packaging applications. Interconnect circuitry in IC substrate packages comprises of stacked microvia that varies in depth from 20microm to 100microm with an aspect ratio of 0.5 to 1.5 and fine line patterns defined by photolithography. Photolithography defined pattern regions incorporate a wide variety of feature sizes including large circular pad structures with diameter of 20microm - 200microm, fine traces with varying widths of 3microm - 30microm and additional planar regions to define a IC substrate package. Electrodeposition of copper is performed to establish the desired circuit. Electrodeposition of copper in IC substrate applications holds certain unique challenges in that they require a low cost manufacturing process that enables a void-free gap fill inside the microvia along with uniform deposition of copper on exposed patterned regions. Deposition time scales to establish the desired metal thickness for such packages could range from several minutes to few hours. This work showcases a reverse pulse electrodeposition methodology that achieves void-free gap fill inside the microvia and uniform plating in FLS (Fine Lines and Spaces) regions with significantly higher deposition rates than traditional approaches. In order to achieve this capability, systematic experimental and simulation studies were performed. A strong correlation of independent parameters that govern the electrodeposition process such as bath temperature, reverse pulse plating parameters and the ratio of electrolyte concentrations is shown to the deposition kinetics and deposition uniformity in fine patterned regions and gap fill rate inside the microvia. Additionally, insight into the physics of via fill process is presented with secondary and tertiary current simulation efforts. Such efforts lead

Copper Homeostasis at the Host-Pathogen Interface*

PubMed Central

Hodgkinson, Victoria; Petris, Michael J.

2012-01-01

The trace element copper is indispensable for all aerobic life forms. Its ability to cycle between two oxidation states, Cu1+ and Cu2+, has been harnessed by a wide array of metalloenzymes that catalyze electron transfer reactions. The metabolic needs for copper are sustained by a complex series of transporters and carrier proteins that regulate its intracellular accumulation and distribution in both pathogenic microbes and their animal hosts. However, copper is also potentially toxic due in part to its ability to generate reactive oxygen species. Recent studies suggest that the macrophage phagosome accumulates copper during bacterial infection, which may constitute an important mechanism of killing. Bacterial countermeasures include the up-regulation of copper export and detoxification genes during infection, which studies suggest are important determinants of virulence. In this minireview, we summarize recent developments that suggest an emerging role for copper as an unexpected component in determining the outcome of host-pathogen interactions. PMID:22389498

Direct patterning of highly-conductive graphene@copper composites using copper naphthenate as a resist for graphene device applications.

PubMed

Bi, Kaixi; Xiang, Quan; Chen, Yiqin; Shi, Huimin; Li, Zhiqin; Lin, Jun; Zhang, Yongzhe; Wan, Qiang; Zhang, Guanhua; Qin, Shiqiao; Zhang, Xueao; Duan, Huigao

2017-11-09

We report an electron-beam lithography process to directly fabricate graphene@copper composite patterns without involving metal deposition, lift-off and etching processes using copper naphthenate as a high-resolution negative-tone resist. As a commonly used industrial painting product, copper naphthenate is extremely cheap with a long shelf time but demonstrates an unexpected patterning resolution better than 10 nm. With appropriate annealing under a hydrogen atmosphere, the produced graphene@copper composite patterns show high conductivity of ∼400 S cm -1 . X-ray diffraction, conformal Raman spectroscopy and X-ray photoelectron spectroscopy were used to analyze the chemical composition of the final patterns. With the properties of high resolution and high conductivity, the patterned graphene@copper composites could be used as conductive pads and interconnects for graphene electronic devices with ohmic contacts. Compared to common fabrication processes involving metal evaporation and lift-off steps, this pattern-transfer-free fabrication process using copper naphthenate resist is direct and simple but allows comparable device performance in practical device applications.

19 CFR 10.98 - Copper-bearing fluxing material.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Copper-bearing fluxing material. 10.98 Section 10... Material § 10.98 Copper-bearing fluxing material. (a) For the purpose of this section, ores usable as a... copper. (b) [Reserved] (c) There shall be filed in connection with the entry of such copper-bearing ores...

19 CFR 10.98 - Copper-bearing fluxing material.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 19 Customs Duties 1 2011-04-01 2011-04-01 false Copper-bearing fluxing material. 10.98 Section 10... Material § 10.98 Copper-bearing fluxing material. (a) For the purpose of this section, ores usable as a... copper. (b) [Reserved] (c) There shall be filed in connection with the entry of such copper-bearing ores...

The development of Zirconia and Copper toughened Alumina ceramic insert

NASA Astrophysics Data System (ADS)

Amalina Sabuan, Nur; Zolkafli, Nurfatini; Mebrahitom, A.; Azhari, Azmir; Mamat, Othman

2018-04-01

Ceramic cutting tools have been utilized in industry for over a century for its productivity and efficiency in machine tools and cutting tool material. However, due to the brittleness property the application has been limited. In order to manufacture high strength ceramic cutting tools, there is a need for suitable reinforcement to improve its toughness. In this case, copper (Cu) and zirconia (ZrO2) powders were added to investigate the hardness and physical properties of the developed composite insert. A uniaxial pre-forming process of the mix powder was done prior to densification by sintering at 1000 and 1300°C. The effect of the composition of the reinforcement on the hardness, density, shrinkage and microstructure of the inserts was investigated. It was found that an optimum density of 3.26 % and hardness 1385HV was obtained for composite of 10wt % zirconia and 10wt% copper at temperature 1000 °C.

Characterization of copper oxides, iron oxides, and zinc copper ferrite desulfurization sorbents by X-ray photoelectron spectroscopy and scanning electron microscopy

NASA Astrophysics Data System (ADS)

Siriwardane, Ranjani V.; Poston, James A.

1993-05-01

Characterization of copper oxides, iron oxides, and zinc copper ferrite desulfurization sorbents was performed by X-ray photoelectron spectroscopy and scanning electron microscopy/energy-dispersive spectroscopy at temperatures of 298 to 823 K. Analysis of copper oxides indicated that the satellite structure of the Cu22p region was absent in the Cu(I) state but was present in the Cu(II) state. Reduction of CuO at room temperature was observed when the ion gauge was placed close to the sample. The satellite structure was absent in all the copper oxides at 823 K in vacuum. Differentiation of the oxidation state of copper utilizing both Cu(L 3M 4,5M 4,5) X-ray-induced Auger lines and Cu2p satellite structure, indicated that the copper in zinc copper ferrite was in the + 1 oxidation state at 823 K. This + 1 state of copper was not significantly changed after exposure to H 2, CO, and H 2O. There was an increase in Cu/Zn ratio and a decrease in Fe/Zn ratio on the surface of zinc copper ferrite at 823 K compared to that at room temperature. These conditions of copper offered the best sulfidation equilibrium for the zinc copper ferrite desulfurization sorbent. Analysis of iron oxides indicated that there was some reduction of both Fe 2O 3 and FeO at 823K. The iron in zinc copper ferrite was similar to that of Fe 2O 3 at room temperature but there was some reduction of this Fe(III) state to Fe(II) at 823 K. This reduction was more enhanced in the presence of H 2 and CO. Reduction to Fe(II) may not be desirable for the lifetime of the sorbent.

Comparison of the toxicities, activities and chemical profiles of raw and processed Xanthii Fructus.

PubMed

Su, Tao; Cheng, Brian Chi-Yan; Fu, Xiu-Qiong; Li, Ting; Guo, Hui; Cao, Hui-Hui; Kwan, Hiu-Yee; Tse, Anfernee Kai-Wing; Yu, Hua; Cao, Hui; Yu, Zhi-Ling

2016-01-22

Although toxic, the Chinese medicinal herb Xanthii Fructus (XF) is commonly used to treat traditional Chinese medicine (TCM) symptoms that resemble cold, sinusitis and arthritis. According to TCM theory, stir-baking (a processing method) can reduce the toxicity and enhance the efficacy of XF. Cytotoxicities of raw XF and processed XF (stir-baked XF, SBXF) were determined by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay in normal liver derived MIHA cells. Nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) mRNA expression were measured by the Griess reagent and quantitative real-time PCR, respectively. The chemical profiles of XF and SBXF were compared using an established ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOF-MS) method. SBXF was less toxic than XF in MIHA cells. Both XF and SBXF had anti-inflammatory effects as demonstrated by their abilities to reduce nitric oxide production as well as inducible nitric oxide synthase mRNA expression in lipopolysaccharide-stimulated RAW 264.7 macrophages. Interestingly, the anti-inflammatory effects of SBXF were more potent than that of XF. By comparing the chemical profiles, we found that seven peaks were lower, while nine other peaks were higher in SBXF than in XF. Eleven compounds including carboxyatractyloside, atractyloside and chlorogenic acid corresponding to eleven individual changed peaks were tentatively identified by matching with empirical molecular formulae and mass fragments, as well as literature data. Our study showed that stir-baking significantly reduced the cytotoxicity and enhanced the anti-inflammatory effects of XF; moreover, with a developed ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry method we differentiated XF and SBXF by their chemical profiles. Further studies are warranted to establish the relationship between the alteration of chemical profiles and the

Molecular imaging and therapy targeting copper metabolism in hepatocellular carcinoma

PubMed Central

Wachsmann, Jason; Peng, Fangyu

2016-01-01

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. Significant efforts have been devoted to identify new biomarkers for molecular imaging and targeted therapy of HCC. Copper is a nutritional metal required for the function of numerous enzymatic molecules in the metabolic pathways of human cells. Emerging evidence suggests that copper plays a role in cell proliferation and angiogenesis. Increased accumulation of copper ions was detected in tissue samples of HCC and many other cancers in humans. Altered copper metabolism is a new biomarker for molecular cancer imaging with position emission tomography (PET) using radioactive copper as a tracer. It has been reported that extrahepatic mouse hepatoma or HCC xenografts can be localized with PET using copper-64 chloride as a tracer, suggesting that copper metabolism is a new biomarker for the detection of HCC metastasis in areas of low physiological copper uptake. In addition to copper modulation therapy with copper chelators, short-interference RNA specific for human copper transporter 1 (hCtr1) may be used to suppress growth of HCC by blocking increased copper uptake mediated by hCtr1. Furthermore, altered copper metabolism is a promising target for radionuclide therapy of HCC using therapeutic copper radionuclides. Copper metabolism has potential as a new theranostic biomarker for molecular imaging as well as targeted therapy of HCC. PMID:26755872

Utilization of Copper Alloys for Marine Applications

NASA Astrophysics Data System (ADS)

Drach, Andrew

Utilization of copper alloy components in systems deployed in marine environment presents potential improvements by reducing maintenance costs, prolonging service life, and increasing reliability. However, integration of these materials faces technological challenges, which are discussed and addressed in this work, including characterization of material performance in seawater environment, hydrodynamics of copper alloy components, and design procedures for systems with copper alloys. To characterize the hydrodynamic behavior of copper alloy nets, mesh geometry of the major types of copper nets currently used in the marine aquaculture are analyzed and formulae for the solidity and strand length are proposed. Experimental studies of drag forces on copper alloy net panels are described. Based on these studies, empirical values for normal drag coefficients are proposed for various types of copper netting. These findings are compared to the previously published data on polymer nets. It is shown that copper nets exhibit significantly lower resistance to normal currents, which corresponds to lower values of normal drag coefficient. The seawater performance (corrosion and biofouling) of copper alloys is studied through the field trials of tensioned and untensioned specimens in a one-year deployment in the North Atlantic Ocean. The corrosion behavior is characterized by weight loss, optical microscopy, and SEM/EDX analyses. The biofouling performance is quantified in terms of the biomass accumulation. To estimate the effects of stray electrical currents on the seawater corrosion measurements, a low cost three-axis stray electric current monitoring device is designed and tested both in the lab and in the 30-day field deployment. The system consists of a remotely operated PC with a set of pseudo-electrodes and a digital compass. The collected data is processed to determine magnitudes of AC and DC components of electric field and dominant AC frequencies. Mechanical behavior of

Biochar and compost as amendments in copper-enriched vineyard soils - stabilization or mobilization of copper?

NASA Astrophysics Data System (ADS)

Soja, Gerhard; Fristak, Vladimir; Wimmer, Bernhard; Bell, Stephen; Chamier Glisczinski, Julia; Pardeller, Georg; Dersch, Georg; Rosner, Franz; Wenzel, Walter; Zehetner, Franz

2016-04-01

Copper is an important ingredient for several fungicides that have been used in agriculture. For organic viticulture, several diseases as e.g. downy mildew (Plasmopara viticola) can only be antagonized with Cu-containing fungicides. This long-lasting dependence on Cu-fungicides has led to a gradual Cu enrichment of vineyard soils in traditional wine-growing areas, occasionally exceeding 300 mg/kg. Although these concentrations do not affect the vines or wine quality, they may impair soil microbiological functions in the top soil layer or the root growth of green cover plants. Therefore measures are demanded that reduce the bioavailability of copper, thereby reducing the ecotoxicological effects. The use of biochar and compost as soil amendment has been suggested as a strategy to immobilize Cu and reduce the exchangeable fractions. This study consisted of lab and greenhouse experiments that were designed to test the sorption and desorption behavior of copper in vineyard soils with or without biochar and/or compost as soil amendment. Slightly acidic soils (pH<6) showed a clearer biochar-induced immobilization of copper with biochar than neutral or alkaline soils. The analyses of leachate waters of microlysimeter experiments showed that the biochar effects were more evident for a reduction of the ionic form Cu2+ than for total soluble copper, even in alkaline soils. Biochar modified with citric or tartaric acid did not significantly decrease the solubility of copper based on total dissolved concentrations although CEC was higher than in unmodified biochar. Treatments consisting of compost only or that had an equal amount of compost and biochar rather had a mobilizing effect on biochar. Sorption experiments with different DOC concentrations and biochar, however, showed a positive effect on copper sorption. Apparently in vineyard soils the predisposition to form organic-Cu-complexes may outbalance the binding possibilities of these complexes to biochar, occasionally

Lead and Copper Control 101

EPA Science Inventory

This presentation is an overview of the most important water treatment strategies for the control of lead and copper release from drinking water corrosion. In addition to the sections specifically on lead and copper treatment, sections are included that cover sampling to find le...

The evolution of machining-induced surface of single-crystal FCC copper via nanoindentation

NASA Astrophysics Data System (ADS)

Zhang, Lin; Huang, Hu; Zhao, Hongwei; Ma, Zhichao; Yang, Yihan; Hu, Xiaoli

2013-05-01

The physical properties of the machining-induced new surface depend on the performance of the initial defect surface and deformed layer in the subsurface of the bulk material. In this paper, three-dimensional molecular dynamics simulations of nanoindentation are preformed on the single-point diamond turning surface of single-crystal copper comparing with that of pristine single-crystal face-centered cubic copper. The simulation results indicate that the nucleation of dislocations in the nanoindentation test on the machining-induced surface and pristine single-crystal copper is different. The dislocation embryos are gradually developed from the sites of homogeneous random nucleation around the indenter in the pristine single-crystal specimen, while the dislocation embryos derived from the vacancy-related defects are distributed in the damage layer of the subsurface beneath the machining-induced surface. The results show that the hardness of the machining-induced surface is softer than that of pristine single-crystal copper. Then, the nanocutting simulations are performed along different crystal orientations on the same crystal surface. It is shown that the crystal orientation directly influences the dislocation formation and distribution of the machining-induced surface. The crystal orientation of nanocutting is further verified to affect both residual defect generations and their propagation directions which are important in assessing the change of mechanical properties, such as hardness and Young's modulus, after nanocutting process.

Bonding and structure of copper nitrenes.

PubMed

Cundari, Thomas R; Dinescu, Adriana; Kazi, Abul B

2008-11-03

Copper nitrenes are of interest as intermediates in the catalytic aziridination of olefins and the amination of C-H bonds. However, despite advances in the isolation and study of late-transition-metal multiply bonded complexes, a bona fide structurally characterized example of a terminal copper nitrene has, to our knowledge, not been reported. In anticipation of such a report, terminal copper nitrenes are studied from a computational perspective. The nitrene complexes studied here are of the form (beta-diketiminate)Cu(NPh). Density functional theory (DFT), complete active space self-consistent-field (CASSCF) electronic structure techniques, and hybrid quantum mechanical/molecular mechanical (QM/MM) methods are employed to study such species. While DFT methods indicate that a triplet (S = 1) is the ground state, CASSCF calculations indicate that a singlet (S = 0) is the ground state, with only a small energy gap between the singlet and triplet. Moreover, the ground-state (open-shell) singlet copper nitrene is found to be highly multiconfigurational (i.e., biradical) and to possess a bent geometry about the nitrene nitrogen, contrasting with the linear nitrene geometry of the triplet copper nitrenes. CASSCF calculations also reveal the existence of a closed-shell singlet state with some degree of multiple bonding character for the copper-nitrene bond.

Seasonal and spatial patterns of metals at a restored copper mine site. I. Stream copper and zinc

USGS Publications Warehouse

Bambic, D.G.; Alpers, Charles N.; Green, P.G.; Fanelli, E.; Silk, W.K.

2006-01-01

Seasonal and spatial variations in metal concentrations and pH were found in a stream at a restored copper mine site located near a massive sulfide deposit in the Foothill copper-zinc belt of the Sierra Nevada, California. At the mouth of the stream, copper concentrations increased and pH decreased with increased streamflow after the onset of winter rain and, unexpectedly, reached extreme values 1 or 2 months after peaks in the seasonal hydrographs. In contrast, aqueous zinc and sulfate concentrations were highest during low-flow periods. Spatial variation was assessed in 400 m of reach encompassing an acidic, metal-laden seep. At this seep, pH remained low (2-3) throughout the year, and copper concentrations were highest. In contrast, the zinc concentrations increased with downstream distance. These spatial patterns were caused by immobilization of copper by hydrous ferric oxides in benthic sediments, coupled with increasing downstream supply of zinc from groundwater seepage.

Planktonic microbial community responses to added copper.

PubMed

Le Jeune, Anne-Hélène; Charpin, Marie; Sargos, Denis; Lenain, Jean-François; Deluchat, Véronique; Ngayila, Nadine; Baudu, Michel; Amblard, Christian

2007-07-20

It is generally agreed that autotrophic organisms and especially phytoplanktonic species can be harmed by copper through its effect on photosystem. However, the impact of copper on other components of the pelagic food web, such as the microbial loop (autotrophic and heterotrophic picoplankton, pigmented and non-pigmented flagellates and ciliates) has received little attention. Indoor experiments were conducted to evaluate the direct and indirect effects of copper, supplied in the range of concentrations used to control cyanobacteria growth in ponds, on non-targeted organisms of natural microbial loop communities sampled in spring and summer. Two copper concentrations were tested (80microgL(-1) and 160microgL(-1) final concentrations), set, respectively, below and above the ligand binding capacity of the water samples. Both caused a significant decrease in the biomass and diversity of pigmented organisms (picophytoplankton and pigmented flagellates). Conversely, the heterotrophic bacterioplankton and the heterotrophic flagellates did not seem to be directly affected by either copper treatment in terms of biomass or diversity, according to the descriptor chosen. The ciliate biomass was significantly reduced with increasing copper concentrations, but differences in sensitivity appeared between spring and summer communities. Potential mixotrophic and nanoplanktorivorous ciliates appeared to be more sensitive to copper treatments than bacterivorous ciliates, suggesting a stronger direct and (or) indirect effect of copper on the former. Copper sulphate treatments had a significant restructuring effect on the microbial loop communities, resulting in a dominance of heterotrophic bacterioplankton among microbial microorganisms 27 days after the beginning of the treatment. The spring microbial communities exhibited a greater sensitivity than the summer communities with respect to their initial compositions.

An Investigation of the Aerodynamic Characteristics of an 0.08-Scale Model of the Chance Vought XF7U-1 Airplane in the Langley High-Speed 7- by 10-Foot Tunnel. Part III - Longitudinal-Control Characteristics TED No. NACA DE308. Part 3; Longitudinal-Control Characteristics, TED No. NACA DE308

NASA Technical Reports Server (NTRS)

Kuhn, Richard E.; King, Thomas J., Jr.

1947-01-01

Tests have been conducted in the Langley high speed 7- by 10-foot tunnel over a Mach number range from 0.40 to 0.91 to determine the stability and control characteristics of an 0,08-scale model of the Chance Vought XF7U-1 airplane. The longitudinal-control characteristics of the complete model are presented in the present report with a limited analysis of the results.

Fabrication of free-standing copper foils covered with highly-ordered copper nanowire arrays

NASA Astrophysics Data System (ADS)

Zaraska, Leszek; Sulka, Grzegorz D.; Jaskuła, Marian

2012-07-01

The through-hole nanoporous anodic aluminum oxide (AAO) membranes with relatively large surface area (ca. 2 cm2) were employed for fabrication of free-standing and mechanically stable copper foils covered with close-packed and highly-ordered copper nanowire arrays. The home-made AAO membranes with different pore diameters and interpore distances were fabricated via a two-step self-organized anodization of aluminum performed in sulfuric acid, oxalic acid and phosphoric acid followed by the pore opening/widening procedure. The direct current (DC) electrodeposition of copper was performed efficiently on both sides of AAO templates. The bottom side of the AAO templates was not insulated and consequently Cu nanowire arrays on thick Cu layers were obtained. The proposed template-assisted fabrication of free-standing copper nanowire array electrodes is a promising method for synthesis of nanostructured current collectors. The composition of Cu nanowires was confirmed by energy dispersive X-Ray spectroscopy (EDS) and X-ray diffraction (XRD) analyses. The structural features of nanowires were evaluated from field emission scanning electron microscopy (FE-SEM) images and compared with the characteristic parameters of anodic alumina membranes.

21 CFR 73.125 - Sodium copper chlorophyllin.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Sodium copper chlorophyllin. 73.125 Section 73.125... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.125 Sodium copper chlorophyllin. (a) Identity. (1) The color additive sodium copper chlorophyllin is a green to black powder prepared from chlorophyll by...

21 CFR 73.125 - Sodium copper chlorophyllin.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Sodium copper chlorophyllin. 73.125 Section 73.125... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.125 Sodium copper chlorophyllin. (a) Identity. (1) The color additive sodium copper chlorophyllin is a green to black powder prepared from chlorophyll by...

21 CFR 73.125 - Sodium copper chlorophyllin.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Sodium copper chlorophyllin. 73.125 Section 73.125... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.125 Sodium copper chlorophyllin. (a) Identity. (1) The color additive sodium copper chlorophyllin is a green to black powder prepared from chlorophyll by...

21 CFR 73.125 - Sodium copper chlorophyllin.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Sodium copper chlorophyllin. 73.125 Section 73.125... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.125 Sodium copper chlorophyllin. (a) Identity. (1) The color additive sodium copper chlorophyllin is a green to black powder prepared from chlorophyll by...

Biochemical characterization of P-type copper ATPases

PubMed Central

Inesi, Giuseppe; Pilankatta, Rajendra; Tadini-Buoninsegni, Francesco

2014-01-01

Copper ATPases, in analogy with other members of the P-ATPase superfamily, contain a catalytic headpiece including an aspartate residue reacting with ATP to form a phosphoenzyme intermediate, and transmembrane helices containing cation-binding sites [TMBS (transmembrane metal-binding sites)] for catalytic activation and cation translocation. Following phosphoenzyme formation by utilization of ATP, bound copper undergoes displacement from the TMBS to the lumenal membrane surface, with no H+ exchange. Although PII-type ATPases sustain active transport of alkali/alkali-earth ions (i.e. Na+, Ca2+) against electrochemical gradients across defined membranes, PIB-type ATPases transfer transition metal ions (i.e. Cu+) from delivery to acceptor proteins and, prominently in mammalian cells, undergo trafficking from/to various membrane compartments. A specific component of copper ATPases is the NMBD (N-terminal metal-binding domain), containing up to six copper-binding sites in mammalian (ATP7A and ATP7B) enzymes. Copper occupancy of NMBD sites and interaction with the ATPase headpiece are required for catalytic activation. Furthermore, in the presence of copper, the NMBD allows interaction with protein kinase D, yielding phosphorylation of serine residues, ATP7B trafficking and protection from proteasome degradation. A specific feature of ATP7A is glycosylation and stabilization on plasma membranes. Cisplatin, a platinum-containing anti-cancer drug, binds to copper sites of ATP7A and ATP7B, and undergoes vectorial displacement in analogy with copper. PMID:25242165

Leaching for recovery of copper from municipal solid waste incineration fly ash: influence of ash properties and metal speciation.

PubMed

Lassesson, Henric; Fedje, Karin Karlfeldt; Steenari, Britt-Marie

2014-08-01

Recovery of metals occurring in significant amounts in municipal solid waste incineration fly ash, such as copper, could offer several advantages: a decreased amount of potentially mobile metal compounds going to landfill, saving of natural resources and a monetary value. A combination of leaching and solvent extraction may constitute a feasible recovery path for metals from municipal solid waste incineration fly ash. However, it has been shown that the initial dissolution and leaching is a limiting step in such a recovery process. The work described in this article was focused on elucidating physical and chemical differences between two ash samples with the aim of explaining the differences in copper release from these samples in two leaching methods. The results showed that the chemical speciation is an important factor affecting the release of copper. The occurrence of copper as phosphate or silicate will hinder leaching, while sulphate and chloride will facilitate leaching. © The Author(s) 2014.

Assessing the Release of Copper from Nanocopper-treated and Conventional Copper-treated Lumber into Marine Waters II: Forms and Bioavailability

EPA Science Inventory

One application of nanocopper is as a wood‐preserving pesticide in pressure‐treated lumber. Recent research has shown that pressure‐treated lumber amended with micronized copper azole (MCA), which contains nanosized copper, releases copper under estuarine and ma...

The Yeast Copper Response Is Regulated by DNA Damage

PubMed Central

Dong, Kangzhen; Addinall, Stephen G.; Lydall, David

2013-01-01

Copper is an essential but potentially toxic redox-active metal, so the levels and distribution of this metal are carefully regulated to ensure that it binds to the correct proteins. Previous studies of copper-dependent transcription in the yeast Saccharomyces cerevisiae have focused on the response of genes to changes in the exogenous levels of copper. We now report that yeast copper genes are regulated in response to the DNA-damaging agents methyl methanesulfonate (MMS) and hydroxyurea by a mechanism(s) that requires the copper-responsive transcription factors Mac1 and AceI, copper superoxide dismutase (Sod1) activity, and the Rad53 checkpoint kinase. Furthermore, in copper-starved yeast, the response of the Rad53 pathway to MMS is compromised due to a loss of Sod1 activity, consistent with the model that yeast imports copper to ensure Sod1 activity and Rad53 signaling. Crucially, the Mac1 transcription factor undergoes changes in its redox state in response to changing levels of copper or MMS. This study has therefore identified a novel regulatory relationship between cellular redox, copper homeostasis, and the DNA damage response in yeast. PMID:23959798

Contact killing and antimicrobial properties of copper.

PubMed

Vincent, M; Duval, R E; Hartemann, P; Engels-Deutsch, M

2018-05-01

With the emergence of antibiotic resistance, the interest for antimicrobial agents has recently increased again in public health. Copper was recognized in 2008 by the United States Environmental Protection Agency (EPA) as the first metallic antimicrobial agent. This led to many investigations of the various properties of copper as an antibacterial, antifungal and antiviral agent. This review summarizes the latest findings about 'contact killing', the mechanism of action of copper nanoparticles and the different ways micro-organisms develop resistance to copper. © 2017 The Society for Applied Microbiology.

Assessing the Release of Copper from Nanocopper-treated and Conventional Copper-treated Lumber into Marine Waters I: Concentrations and Rates

EPA Science Inventory

Little is known about the release of metal engineered nanomaterials (ENMs) from consumer goods, including lumber treated with micronized copper. Micronized copper is a recent form of antifouling wood preservative containing nanosized copper particles for use in pressure‐tre...

21 CFR 582.5260 - Copper gluconate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5260 Copper gluconate. (a) Product. Copper gluconate. (b) Tolerance. This substance is...

21 CFR 582.5260 - Copper gluconate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5260 Copper gluconate. (a) Product. Copper gluconate. (b) Tolerance. This substance is...

21 CFR 582.5260 - Copper gluconate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5260 Copper gluconate. (a) Product. Copper gluconate. (b) Tolerance. This substance is...

21 CFR 582.5260 - Copper gluconate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5260 Copper gluconate. (a) Product. Copper gluconate. (b) Tolerance. This substance is...

21 CFR 582.5260 - Copper gluconate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5260 Copper gluconate. (a) Product. Copper gluconate. (b) Tolerance. This substance is...

Copper Tolerance and Characterization of a Copper-Responsive Operon, copYAZ, in an M1T1 Clinical Strain of Streptococcus pyogenes.

PubMed

Young, Christie A; Gordon, Lily D; Fang, Zhong; Holder, Robert C; Reid, Sean D

2015-08-01

Infection with Streptococcus pyogenes is associated with a breadth of clinical manifestations ranging from mild pharyngitis to severe necrotizing fasciitis. Elevated levels of intracellular copper are highly toxic to this bacterium, and thus, the microbe must tightly regulate the level of this metal ion by one or more mechanisms, which have, to date, not been clearly defined. In this study, we have identified two virulence mechanisms by which S. pyogenes protects itself against copper toxicity. We defined a set of putative genes, copY (for a regulator), copA (for a P1-type ATPase), and copZ (for a copper chaperone), whose expression is regulated by copper. Our results indicate that these genes are highly conserved among a range of clinical S. pyogenes isolates. The copY, copA, and copZ genes are induced by copper and are transcribed as a single unit. Heterologous expression assays revealed that S. pyogenes CopA can confer copper tolerance in a copper-sensitive Escherichia coli mutant by preventing the accumulation of toxic levels of copper, a finding that is consistent with a role for CopA in copper export. Evaluation of the effect of copper stress on S. pyogenes in a planktonic or biofilm state revealed that biofilms may aid in protection during initial exposure to copper. However, copper stress appears to prevent the shift from the planktonic to the biofilm state. Therefore, our results indicate that S. pyogenes may use several virulence mechanisms, including altered gene expression and a transition to and from planktonic and biofilm states, to promote survival during copper stress. Bacterial pathogens encounter multiple stressors at the host-pathogen interface. This study evaluates a virulence mechanism(s) utilized by S. pyogenes to combat copper at sites of infection. A better understanding of pathogen tolerance to stressors such as copper is necessary to determine how host-pathogen interactions impact bacterial survival during infections. These insights may

Extraction-spectrophotometric determination of traces of gold in copper in silver, lead, blister copper, copper concentrate and anode slime with 4,4'-bis(dimethylamino)-thiobenzophenone.

PubMed

Tsukahara, I

1977-10-01

A sensitive spectrophotometric method has been developed for the determination of gold in copper, silver, lead, blister copper, copper concentrate and anode slime. Optimal conditions have been established for the extraction and determination of gold. Gold is extracted as its bromo complex with tri-n-octylamine and determined photometrically with 4,4'-bis(dimethylamino)thiobenzophenone; the absorbance of the organic phase is measured at 540 nm and the apparent molar absorptivity is about 1.2 x 10(5) 1.mole(-1). cm(-1). As little as 0.1 or 0.2 ppm of gold in these materials can be determined.

Copper Homeostasis in Escherichia coli and Other Enterobacteriaceae.

PubMed

Rensing, Christopher; Franke, Sylvia

2007-04-01

An interesting model for studying environmental influences shaping microbial evolution is provided by a multitude of copper resistance and copper homeostasis determinants in enteric bacteria. This review describes these determinants and tries to relate their presence to the habitat of the respective organism, as a current hypothesis predicts that the environment should determine an organism's genetic makeup. In Escherichia coli there are four regulons that are induced in the presence of copper. Two, the CueR and the CusR regulons, are described in detail. A central component regulating intracellular copper levels, present in all free-living enteric bacteria whose genomes have so far been sequenced, is a Cu(I)translocating P-type ATPase. The P-type ATPase superfamily is a ubiquitous group of proteins involved in the transport of charged substrates across biological membranes. Whereas some components involved in copper homeostasis can be found in both anaerobes and aerobes, multi-copper oxidases (MCOs) implicated in copper tolerance in E. coli, such as CueO and the plasmid-based PcoA, can be found only in aerobic organisms. Several features indicate that CueO, PcoA, and other related MCOs are specifically adapted to combat copper-mediated oxidative damage. In addition to these well-characterized resistance operons, there are numerous other genes that appear to be involved in copper binding and trafficking that have not been studied in great detail. SilE and its homologue PcoE, for example, are thought to effect the periplasmic binding and sequestration of silver and copper, respectively.

The cardiac copper chaperone proteins Sco1 and CCS are up-regulated, but Cox 1 and Cox4 are down-regulated, by copper deficiency.

PubMed

Getz, Jean; Lin, Dingbo; Medeiros, Denis M

2011-10-01

Copper is ferried in a cell complexed to chaperone proteins, and in the heart much copper is required for cytochrome c oxidase (Cox). It is not completely understood how copper status affects the levels of these proteins. Here we determined if dietary copper deficiency could up- or down-regulate select copper chaperone proteins and Cox subunits 1 and 4 in cardiac tissue of rats. Sixteen weanling male Long-Evans rats were randomized into treatment groups, one group receiving a copper-deficient diet (<1 mg Cu/kg diet) and one group receiving a diet containing adequate copper (6 mg Cu/kg diet) for 5 weeks. Hearts were removed, weighed, and non-myofibrillar proteins separated to analyze for levels of CCS, Sco1, Ctr1, Cox17, Cox1, and Cox4 by SDS-PAGE and Western blotting. No changes were observed in the concentrations of CTR1 and Cox17 between copper-adequate and copper-deficient rats. CCS and Sco1 were up-regulated and Cox1 and Cox4 were both down-regulated as a result of copper deficiency. These data suggest that select chaperone proteins and may be up-regulated, and Cox1 and 4 down-regulated, by a dietary copper deficiency, whereas others appear not to be affected by copper status.

Copper Acquisition and Utilization in Fungi.

PubMed

Smith, Aaron D; Logeman, Brandon L; Thiele, Dennis J

2017-09-08

Fungal cells colonize and proliferate in distinct niches, from soil and plants to diverse tissues in human hosts. Consequently, fungi are challenged with the goal of obtaining nutrients while simultaneously elaborating robust regulatory mechanisms to cope with a range of availability of nutrients, from scarcity to excess. Copper is essential for life but also potentially toxic. In this review we describe the sophisticated homeostatic mechanisms by which fungi acquire, utilize, and control this biochemically versatile trace element. Fungal pathogens, which can occupy distinct host tissues that have their own intrinsic requirements for copper homeostasis, have evolved mechanisms to acquire copper to successfully colonize the host, disseminate to other tissues, and combat host copper bombardment mechanisms that would otherwise mitigate virulence.

Recovery of copper and water from copper-electroplating wastewater by the combination process of electrolysis and electrodialysis.

PubMed

Peng, Changsheng; Liu, Yanyan; Bi, Jingjing; Xu, Huizhen; Ahmed, Abou-Shady

2011-05-30

In this paper, a laboratory-scale process which combined electrolysis (EL) and electrodialysis (ED) was developed to treat copper-containing wastewater. The feasibility of such process for copper recovery as well as water reuse was determined. Effects of three operating parameters, voltage, initial Cu(2+) concentration and water flux on the recovery of copper and water were investigated and optimized. The results showed that about 82% of copper could be recovered from high concentration wastewater (HCW, >400mg/L) by EL, at the optimal conditions of voltage 2.5 V/cm and water flux 4 L/h; while 50% of diluted water could be recycled from low concentration wastewater (LCW, <200mg/L) by ED, at the optimal conditions of voltage 40 V and water flux 4 L/h. However, because of the limitation of energy consumption (EC), LCW for EL and HCW for ED could not be treated effectively, and the effluent water of EL and concentrated water of ED should be further treated before discharged. Therefore, the combination process of EL and ED was developed to realize the recovery of copper and water simultaneously from both HCW and LCW. The results of the EL-ED process showed that almost 99.5% of copper and 100% of water could be recovered, with the energy consumption of EL ≈ 3 kW h/kg and ED ≈ 2 kW h/m(3). According to SEM and EDX analysis, the purity of recovered copper was as high as 97.9%. Copyright © 2011 Elsevier B.V. All rights reserved.

Adaptation of Selenastrum capricornutum (Chlorophyceae) to copper

USGS Publications Warehouse

Kuwabara, J.S.; Leland, H.V.

1986-01-01

Selenastrum capricornutum Printz, growing in a chemically defined medium, was used as a model for studying adaptation of algae to a toxic metal (copper) ion. Cells exhibited lag-phase adaptation to 0.8 ??M total Cu (10-12 M free ion concentration) after 20 generations of Cu exposure. Selenastrum adapted to the same concentration when Cu was gradually introduced over an 8-h period using a specially designed apparatus that provided a transient increase in exposure concentration. Cu adaptation was not attributable to media conditioning by algal exudates. Duration of lag phase was a more sensitive index of copper toxicity to Selenastrum that was growth rate or stationary-phase cell density under the experimental conditions used. Chemical speciation of the Cu dosing solution influenced the duration of lag phase even when media formulations were identical after dosing. Selenastrum initially exposed to Cu in a CuCl2 injection solution exhibited a lag phase of 3.9 d, but this was reduced to 1.5 d when a CuEDTA solution was used to achieve the same total Cu and EDTA concentrations. Physical and chemical processes that accelerated the rate of increase in cupric ion concentration generally increased the duration of lag phase. ?? 1986.

Effect of annealing temperature on the properties of copper oxide films prepared by dip coating technique

NASA Astrophysics Data System (ADS)

Raship, N. A.; Sahdan, M. Z.; Adriyanto, F.; Nurfazliana, M. F.; Bakri, A. S.

2017-01-01

Copper oxide films were grown on silicon substrates by sol-gel dip coating method. In order to study the effects of annealing temperature on the properties of copper oxide films, the temperature was varied from 200 °C to 450 °C. In the process of dip coating, the substrate is withdrawn from the precursor solution with uniform velocity to obtain a uniform coating before undergoing an annealing process to make the copper oxide film polycrystalline. The physical properties of the copper oxide films were measured by an X-ray diffraction (XRD), a field emission scanning electron microscope (FESEM), an atomic force microscopy (AFM) and a four point probe instrument. From the XRD results, we found that pure cuprite (Cu2O) phase can be obtained by annealing the films annealed at 200 °C. Films annealed at 300 °C had a combination phase which consists of tenorite (CuO) and cuprite (Cu2O) phase while pure tenorite (CuO) phase can be obtained at 450 °C annealing temperature. The surface microstructure showed that the grains size is increased whereas the surface roughness is increased and then decreases by increasing in annealing temperature. The films showed that the resistivity decreased with increasing annealing temperature. Consequently, it was observed that annealing temperature has strong effects on the structural, morphological and electrical properties of copper oxide films.

[Use of copper oxide wire particles (Copinox) for the prevention of congenital copper deficiency in a herd of German Improved Fawn breed of goat].

PubMed

Winter, P; Hochsteiner, W; Chizzola, R

2004-10-01

In a herd of German Improved Fawn breed of goat in the year 2000 neonatal kid losses due to congenital copper deficiencies were observed. To clarify the problems and to prevent losses in the next breeding season serum copper levels of 10 dams and four control Boer goats were investigated at four time points during one year. Additionally ten kids of the following year were sampled and the serum copper levels were studied. Immediatly after parturition and 8 weeks later the dams showed low serum copper levels (10.4 +/- 11.1 micromol/l, 5.7 +/- 2.9 micromol/l resp.). At the end of the pasture season an increase of serum copper could be measured (19.3 +/- 16.0 micromol/l). To prevent enzootic ataxia due to congenital copper deficiency, the dams were treated with copper oxide wire particles in the next late gestation. At this time point serum copper concentrations started to decrease (18.5 +/- 8.4 micromol/l). The re-examination 3 month later demonstrated an increase of the serum mean copper concentrations up to 23.4 micromol/l in the dams and to 16.2 micromol/l in the kids. The serum copper levels were significantly higher compared to the levels the year before. Big variation of the serum copper levels in the control Boer goats occurred during the year, but no clinical symptoms of copper deficiency could be observed. The copper levels in the grass and soil samples were 6.8 mg/kg and 0.2 mg/kg dry substance, respectively. A secondary copper deficiency based on cadmium could be excluded through the low levels of soil samples. The contents of sulphur and molybdenum were not determined. The results indicate that the German Improved Fawn breed of goats suffered from a primary copper deficiency due to the inefficient mineral supplementation. The administration of Copinox in the last third of the gestation leads to a continious raising of the copper concentrations in the serum and is suited to prevent ataxia due to congential copper deficiency in neonatal kids.

Diffusible signal factor (DSF) synthase RpfF of Xylella fastidiosa is a multifunction protein also required for response to DSF.

PubMed

Ionescu, Michael; Baccari, Clelia; Da Silva, Aline Maria; Garcia, Angelica; Yokota, Kenji; Lindow, Steven E

2013-12-01

Xylella fastidiosa, like related Xanthomonas species, employs an Rpf cell-cell communication system consisting of a diffusible signal factor (DSF) synthase, RpfF, and a DSF sensor, RpfC, to coordinate expression of virulence genes. While phenotypes of a ΔrpfF strain in Xanthomonas campestris could be complemented by its own DSF, the DSF produced by X. fastidiosa (XfDSF) did not restore expression of the XfDSF-dependent genes hxfA and hxfB to a ΔrpfF strain of X. fastidiosa, suggesting that RpfF is involved in XfDSF sensing or XfDSF-dependent signaling. To test this conjecture, rpfC and rpfF of X. campestris were replaced by those of X. fastidiosa, and the contribution of each gene to the induction of a X. campestris DSF-dependent gene was assessed. As in X. fastidiosa, XfDSF-dependent signaling required both X. fastidiosa proteins RpfF and RpfC. RpfF repressed RpfC signaling activity, which in turn was derepressed by XfDSF. A mutated X. fastidiosa RpfF protein with two substitutions of glutamate to alanine in its active site was incapable of XfDSF production yet enabled a response to XfDSF, indicating that XfDSF production and the response to XfDSF are two separate functions in which RpfF is involved. This mutant was also hypervirulent to grape, demonstrating the antivirulence effects of XfDSF itself in X. fastidiosa. The Rpf system of X. fastidiosa is thus a novel example of a quorum-sensing signal synthase that is also involved in the response to the signal molecule that it synthesizes.

Diffusible Signal Factor (DSF) Synthase RpfF of Xylella fastidiosa Is a Multifunction Protein Also Required for Response to DSF

PubMed Central

Ionescu, Michael; Baccari, Clelia; Da Silva, Aline Maria; Garcia, Angelica; Yokota, Kenji

2013-01-01

Xylella fastidiosa, like related Xanthomonas species, employs an Rpf cell-cell communication system consisting of a diffusible signal factor (DSF) synthase, RpfF, and a DSF sensor, RpfC, to coordinate expression of virulence genes. While phenotypes of a ΔrpfF strain in Xanthomonas campestris could be complemented by its own DSF, the DSF produced by X. fastidiosa (XfDSF) did not restore expression of the XfDSF-dependent genes hxfA and hxfB to a ΔrpfF strain of X. fastidiosa, suggesting that RpfF is involved in XfDSF sensing or XfDSF-dependent signaling. To test this conjecture, rpfC and rpfF of X. campestris were replaced by those of X. fastidiosa, and the contribution of each gene to the induction of a X. campestris DSF-dependent gene was assessed. As in X. fastidiosa, XfDSF-dependent signaling required both X. fastidiosa proteins RpfF and RpfC. RpfF repressed RpfC signaling activity, which in turn was derepressed by XfDSF. A mutated X. fastidiosa RpfF protein with two substitutions of glutamate to alanine in its active site was incapable of XfDSF production yet enabled a response to XfDSF, indicating that XfDSF production and the response to XfDSF are two separate functions in which RpfF is involved. This mutant was also hypervirulent to grape, demonstrating the antivirulence effects of XfDSF itself in X. fastidiosa. The Rpf system of X. fastidiosa is thus a novel example of a quorum-sensing signal synthase that is also involved in the response to the signal molecule that it synthesizes. PMID:24056101

Study on copper kinetics in processing sulphide ore mixed with copper and zinc with sulfuric acid leaching under pressure

NASA Astrophysics Data System (ADS)

Wen-bo, LUO; Ji-kun, WANG; Yin, GAN

2018-01-01

Sulphide ore mixed with copper and zinc is processed with pressure acid leaching. Research is conducted on the copper kinetic. The stirring rate is set at 600 rpm which could eliminate the influence of external diffusions. Research is conducted on the factors affecting the copper leaching kinetic are temperature, pressure, concentration of sulfuric acid, particle size. The result shows that the apparent activity energy is 50.7 KJ/mol. We could determine that the copper leaching process is shrinking core model of chemical reaction control and work out the leaching equation.

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.

Copper tolerance in Frankia sp. strain EuI1c involves surface binding and copper transport.

PubMed

Rehan, Medhat; Furnholm, Teal; Finethy, Ryan H; Chu, Feixia; El-Fadly, Gomaah; Tisa, Louis S

2014-09-01

Several Frankia strains have been shown to be copper-tolerant. The mechanism of their copper tolerance was investigated for Frankia sp. strain EuI1c. Copper binding was shown by binding studies. Unusual globular structures were observed on the surface of the bacterium. These globular structures were composed of aggregates containing many relatively smaller "leaf-like" structures. Scanning electron microscopy with energy-dispersive X-ray (SEM-EDAX) analysis of these structures indicated elevated copper and phosphate levels compared to the control cells. Fourier transform infrared spectroscopy (FTIR) analysis indicated an increase in extracellular phosphate on the cell surface of copper-stressed cells. Bioinformatics' analysis of the Frankia sp. strain EuI1c genome revealed five potential cop genes: copA, copZ, copC, copCD, and copD. Experiments with Frankia sp. strain EuI1c using qRT-PCR indicated an increase in messenger RNA (mRNA) levels of the five cop genes upon Cu(2+) stress. After 5 days of Cu(2+) stress, the copA, copZ, copC, copCD, and copD mRNA levels increased 25-, 8-, 18-, 18-, and 25-fold, respectively. The protein profile of Cu(2+)-stressed Frankia sp. strain EuI1c cells revealed the upregulation of a 36.7 kDa protein that was identified as FraEuI1c_1092 (sulfate-binding periplasmic transport protein). Homologues of this gene were only present in the genomes of the Cu(2+)-resistant Frankia strains (EuI1c, DC12, and CN3). These data indicate that copper tolerance by Frankia sp. strain EuI1c involved the binding of copper to the cell surface and transport proteins.

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.

Resistance mechanisms of Mycobacterium tuberculosis against phagosomal copper overload

PubMed Central

Rowland, Jennifer L.; Niederweis, Michael

2012-01-01

SUMMARY Mycobacterium tuberculosis is an important bacterial pathogen with an extremely slow growth rate, an unusual outer membrane of very low permeability and a cunning ability to survive inside the human host despite a potent immune response. A key trait of M. tuberculosis is to acquire essential nutrients while still preserving its natural resistance to toxic compounds. In this regard, copper homeostasis mechanisms are particularly interesting, because copper is an important element for bacterial growth, but copper overload is toxic. In M. tuberculosis at least two enzymes require copper as a cofactor: the Cu/Zn-superoxide dismutase SodC and the cytochrome c oxidase which is essential for growth in vitro. Mutants of M. tuberculosis lacking the copper metallothionein MymT, the efflux pump CtpV and the membrane protein MctB are more susceptible to copper indicating that these proteins are part of a multipronged system to balance intracellular copper levels. Recent evidence showed that part of copper toxicity is a reversible damage of accessible Fe-S clusters of dehydratases and the displacement of other divalent cations such as zinc and manganese as cofactors in proteins. There is accumulating evidence that macrophages use copper to poison bacteria trapped inside phagosomes. Here, we review the rapidly increasing knowledge about copper homeostasis mechanisms in M. tuberculosis and contrast those with similar mechanisms in E. coli. These findings reveal an intricate interplay between the host which aims to overload the phagosome with copper and M. tuberculosis which utilizes several mechanisms to reduce the toxic effects of excess copper. PMID:22361385