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Sample records for copper ion resistance

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

    DEFF Research Database (Denmark)

    Elguindi, J; Moffitt, S; Hasman, Henrik

    2010-01-01

    The rapid killing of various bacteria in contact with metallic copper is thought to be influenced by the 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...

  2. Focused ion beam sectioning and lift-out method for copper and resist vias in organic low-k dielectrics.

    Science.gov (United States)

    Crawford, E J; Gignac, L; Barth, K; Petrus, J; Levine, E

    2002-12-01

    The focused ion beam lift-out technique for scanning electron microscope (SEM) and transmission electron microscope (TEM) sample preparation was shown to be applicable to copper/low-k dielectric semiconductor technology. High resolution SEM, TEM, and scanning transmission electron microscope analyses were performed on metal contacts and resist vias with no evidence of the interface damage or metal smearing commonly observed with mechanical polishing. Ion milling of the sample ex situ to the substrate provided decoration and adjustment of the exposed plane of the section when necessary for SEM analysis.

  3. Proteomic Analysis of Drug-Resistant Mycobacteria: Co-Evolution of Copper and INH Resistance

    OpenAIRE

    Yuling Chen; Fan Yang; Zhongyuan Sun; Qingtao Wang; Kaixia Mi; Haiteng Deng

    2015-01-01

    Tuberculosis, caused by the pathogen Mycobacterium tuberculosis, is a worldwide public health threat. Mycobacterium tuberculosis is capable of resisting various stresses in host cells, including high levels of ROS and copper ions. To better understand the resistance mechanisms of mycobacteria to copper, we generated a copper-resistant strain of Mycobacterium smegmatis, mc2155-Cu from the selection of copper sulfate treated-bacteria. The mc2155-Cu strain has a 5-fold higher resistance to coppe...

  4. Isolation and characterization of bacteria resistant to metallic copper surfaces.

    Science.gov (United States)

    Santo, Christophe Espírito; Morais, Paula Vasconcelos; Grass, Gregor

    2010-03-01

    Metallic copper alloys have recently attracted attention as a new antimicrobial weapon for areas where surface hygiene is paramount. Currently it is not understood on a molecular level how metallic copper kills microbes, but previous studies have demonstrated that a wide variety of bacteria, including Escherichia coli, Staphylococcus aureus, and Clostridium difficile, are inactivated within minutes or a few hours of exposure. In this study, we show that bacteria isolated from copper alloy coins comprise strains that are especially resistant against the toxic properties exerted by dry metallic copper surfaces. The most resistant of 294 isolates were Gram-positive staphylococci and micrococci, Kocuria palustris, and Brachybacterium conglomeratum but also included the proteobacterial species Sphingomonas panni and Pseudomonas oleovorans. Cells of some of these bacterial strains survived on copper surfaces for 48 h or more. Remarkably, when these dry-surface-resistant strains were exposed to moist copper surfaces, resistance levels were close to those of control strains and MICs for copper ions were at or below control strain levels. This suggests that mechanisms conferring resistance against dry metallic copper surfaces in these newly isolated bacterial strains are different from well-characterized copper ion detoxification systems. Furthermore, staphylococci on coins did not exhibit increased levels of resistance to antibiotics, arguing against coselection with copper surface resistance traits.

  5. Proteomic Analysis of Drug-Resistant Mycobacteria: Co-Evolution of Copper and INH Resistance.

    Directory of Open Access Journals (Sweden)

    Yuling Chen

    Full Text Available Tuberculosis, caused by the pathogen Mycobacterium tuberculosis, is a worldwide public health threat. Mycobacterium tuberculosis is capable of resisting various stresses in host cells, including high levels of ROS and copper ions. To better understand the resistance mechanisms of mycobacteria to copper, we generated a copper-resistant strain of Mycobacterium smegmatis, mc2155-Cu from the selection of copper sulfate treated-bacteria. The mc2155-Cu strain has a 5-fold higher resistance to copper sulfate and a 2-fold higher resistance to isoniazid (INH than its parental strain mc2155, respectively. Quantitative proteomics was carried out to find differentially expressed proteins between mc2155 and mc2155-Cu. Among 345 differentially expressed proteins, copper-translocating P-type ATPase was up-regulated, while all other ABC transporters were down-regulated in mc2155-Cu, suggesting copper-translocating P-type ATPase plays a crucial role in copper resistance. Results also indicated that the down-regulation of metabolic enzymes and decreases in cellular NAD, FAD, mycothiol, and glutamine levels in mc2155-Cu were responsible for its slowing growth rate as compared to mc2155. Down-regulation of KatG2 expression in both protein and mRNA levels indicates the co-evolution of copper and INH resistance in copper resistance bacteria, and provides new evidence to understanding of the molecular mechanisms of survival of mycobacteria under stress conditions.

  6. Proteomic Analysis of Drug-Resistant Mycobacteria: Co-Evolution of Copper and INH Resistance.

    Science.gov (United States)

    Chen, Yuling; Yang, Fan; Sun, Zhongyuan; Wang, Qingtao; Mi, Kaixia; Deng, Haiteng

    2015-01-01

    Tuberculosis, caused by the pathogen Mycobacterium tuberculosis, is a worldwide public health threat. Mycobacterium tuberculosis is capable of resisting various stresses in host cells, including high levels of ROS and copper ions. To better understand the resistance mechanisms of mycobacteria to copper, we generated a copper-resistant strain of Mycobacterium smegmatis, mc2155-Cu from the selection of copper sulfate treated-bacteria. The mc2155-Cu strain has a 5-fold higher resistance to copper sulfate and a 2-fold higher resistance to isoniazid (INH) than its parental strain mc2155, respectively. Quantitative proteomics was carried out to find differentially expressed proteins between mc2155 and mc2155-Cu. Among 345 differentially expressed proteins, copper-translocating P-type ATPase was up-regulated, while all other ABC transporters were down-regulated in mc2155-Cu, suggesting copper-translocating P-type ATPase plays a crucial role in copper resistance. Results also indicated that the down-regulation of metabolic enzymes and decreases in cellular NAD, FAD, mycothiol, and glutamine levels in mc2155-Cu were responsible for its slowing growth rate as compared to mc2155. Down-regulation of KatG2 expression in both protein and mRNA levels indicates the co-evolution of copper and INH resistance in copper resistance bacteria, and provides new evidence to understanding of the molecular mechanisms of survival of mycobacteria under stress conditions.

  7. Simultaneous Platinum and Copper Ion Attachment to a Human Copper Chaperone Protein

    Science.gov (United States)

    Hodak, Miroslav; Cvitkovic, John; Yu, Corey; Dmitriev, Oleg; Kaminski, George; Bernholc, Jerry

    2015-03-01

    Cisplatin is a potent anti-cancer drug based on a platinum ion. However, its effectiveness is decreased by cellular resistance, which involves cisplatin attaching to copper transport proteins. One of such proteins is Atox1, where cisplatin attaches to the copper binding site. Surprisingly, it was shown that both cisplatin and copper can attach to Atox1 at the same time. To study this double metal ion attachment, we use the KS/FD DFT method, which combines Kohn-Sham DFT with frozen-density DFT to achieve efficient quantum-mechanical description of explicit solvent. Calculations have so far investigated copper ion attachment to CXXC motifs present in Atox1. The addition of the platinum ion and the competition between the two metals is currently being studied. These calculations start from a molecular mechanics (MM) structural model, in which glutathione groups provide additional ligands to the Pt ion. Our goals are to identify possible Cu-Pt structures and to determine whether copper/platinum attachment is competitive, independent, or cooperative. Results will be compared to the 1H, N1 5 -HSQC NMR experiments, in which binding of copper and cisplatin to Atox1 produces distinct secondary chemical shift signatures, allowing for kinetic studies of simultaneous metal binding.

  8. Interactions of catechins with copper ions

    OpenAIRE

    Řihošková, Petra

    2014-01-01

    Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical botanic and ecology Candidate: Mgr. Petra Řihošková Supervisor: PharmDr. Jana Karlíčková, Ph.D. Title of Thesis: Interactions of catechins with copper ions Keywords: catechins, chelating activity, copper, bathocuproine, hematoxylin, antioxidants Flavonoids are a class of plant polyphenols with significant antioxidant activity, which positively affects human health. Flavonoids are able to chelate me...

  9. Bacterial antimicrobial metal ion resistance.

    Science.gov (United States)

    Hobman, Jon L; Crossman, Lisa C

    2015-05-01

    Metals such as mercury, arsenic, copper and silver have been used in various forms as antimicrobials for thousands of years with until recently, little understanding of their mode of action. The discovery of antibiotics and new organic antimicrobial compounds during the twentieth century saw a general decline in the clinical use of antimicrobial metal compounds, with the exception of the rediscovery of the use of silver for burns treatments and niche uses for other metal compounds. Antibiotics and new antimicrobials were regarded as being safer for the patient and more effective than the metal-based compounds they supplanted. Bacterial metal ion resistances were first discovered in the second half of the twentieth century. The detailed mechanisms of resistance have now been characterized in a wide range of bacteria. As the use of antimicrobial metals is limited, it is legitimate to ask: are antimicrobial metal resistances in pathogenic and commensal bacteria important now? This review details the new, rediscovered and 'never went away' uses of antimicrobial metals; examines the prevalence and linkage of antimicrobial metal resistance genes to other antimicrobial resistance genes; and examines the evidence for horizontal transfer of these genes between bacteria. Finally, we discuss the possible implications of the widespread dissemination of these resistances on re-emergent uses of antimicrobial metals and how this could impact upon the antibiotic resistance problem. © 2014 The Authors.

  10. Genome Sequences of Two Copper-Resistant Escherichia coli Strains Isolated from Copper-Fed Pigs

    DEFF Research Database (Denmark)

    Lüthje, Freja L.; Hasman, Henrik; Aarestrup, Frank Møller;

    2014-01-01

    The draft genome sequences of two copper-resistant Escherichia coli strains were determined. These had been isolated from copper-fed pigs and contained additional putative operons conferring copper and other metal and metalloid resistances.......The draft genome sequences of two copper-resistant Escherichia coli strains were determined. These had been isolated from copper-fed pigs and contained additional putative operons conferring copper and other metal and metalloid resistances....

  11. 铜离子转运蛋白家族与肺癌顺铂耐药的研究进展%Research progress on copper ion transport protein family and cisplatin drug resistance in lung cancer

    Institute of Scientific and Technical Information of China (English)

    阳甜; 陈天君; 陈明伟

    2012-01-01

    铂类药作为化疗一种关键药之一,被广泛用于治疗各种恶性肿瘤,如卵巢、膀胱、头颈部肿瘤及肺癌.但铂类耐药的发生限制了化疗反应,影响了患者的预后.目前在铂类耐药的机制方面已经有一些重要的发展,其中之一是肿瘤铂类耐药与细胞内浓度的蓄积之间的相关性,摄入的减少和泵出过多均可减少药物在细胞内的聚积,导致耐药.但是具体耐药机制尚不清楚.铜离子动态平衡是由铜离子转运蛋白及其分子伴侣来维持.铜离子转运蛋白家族包括铜离子转运蛋白和铜离子转运磷酸化ATP酶.本文将就铜离子转运蛋白家族与肺癌顺铂耐药作一综述.%Cisplatin is one of the most important chemotherapeutic agents,commonly used for treatment of various cancers including ovary,endometrial,lung and gastric cancer.The secondary drugresistance,however,limits the efficacy of chemotherapy and consequently compromises the prognosis of patients.Recently,there have been some important developments in the understanding of mechanisms of tumor resistance to cisplatin.One of them is concerning the association between the tumor resistance to platinum drugs and the reduced intracellular accumulation owing to impaired drug intake and enhanced outward transport.However,mechanisms for transporting platinum drugs were not known until recently studies have shown that copper transporters may be involved in the transport of platinum-based anticancer drugs.Body copper homeostasis is maintained by a group of proteins including copper transporters and chaperones.Copper transporters include copper transporter 1 and copper-transporting P-type adenosine triphosphatase.This paper will state copper ion transport protein family and cisplatin drug resistance in lung cancer.

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

    Science.gov (United States)

    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.

  13. Proteomic Analysis of Drug-Resistant Mycobacteria: Co-Evolution of Copper and INH Resistance

    National Research Council Canada - National Science Library

    Chen, Yuling; Yang, Fan; Sun, Zhongyuan; Wang, Qingtao; Mi, Kaixia; Deng, Haiteng

    2015-01-01

    .... To better understand the resistance mechanisms of mycobacteria to copper, we generated a copper-resistant strain of Mycobacterium smegmatis, mc2155-Cu from the selection of copper sulfate treated-bacteria...

  14. Copper ion liquid-like thermoelectrics

    Science.gov (United States)

    Liu, Huili; Shi, Xun; Xu, Fangfang; Zhang, Linlin; Zhang, Wenqing; Chen, Lidong; Li, Qiang; Uher, Ctirad; Day, Tristan; Snyder, G. Jeffrey

    2012-05-01

    Advanced thermoelectric technology offers a potential for converting waste industrial heat into useful electricity, and an emission-free method for solid state cooling. Worldwide efforts to find materials with thermoelectric figure of merit, zT values significantly above unity, are frequently focused on crystalline semiconductors with low thermal conductivity. Here we report on Cu2-xSe, which reaches a zT of 1.5 at 1,000 K, among the highest values for any bulk materials. Whereas the Se atoms in Cu2-xSe form a rigid face-centred cubic lattice, providing a crystalline pathway for semiconducting electrons (or more precisely holes), the copper ions are highly disordered around the Se sublattice and are superionic with liquid-like mobility. This extraordinary ‘liquid-like’ behaviour of copper ions around a crystalline sublattice of Se in Cu2-xSe results in an intrinsically very low lattice thermal conductivity which enables high zT in this otherwise simple semiconductor. This unusual combination of properties leads to an ideal thermoelectric material. The results indicate a new strategy and direction for high-efficiency thermoelectric materials by exploring systems where there exists a crystalline sublattice for electronic conduction surrounded by liquid-like ions.

  15. Copper Ion as a New Leakage Tracer

    Directory of Open Access Journals (Sweden)

    Modaresi J.

    2013-12-01

    Full Text Available Statement of Problem: Most failures of root canal treatments are caused by bacteria. Studies showed that the most common cause of endodontic failures were the incomplete obturation of the root canal and the lack of adequate apical seal. Some in-vitro methods are used to estimate sealing quality, generally by measuring microleakage that allows the tracer agent to penetrate the filled canal.Purpose: Conventional methods of evaluating the seal of endodontically treated teeth are complicated and have some drawbacks. We used copper ion diffusion method to assess the leakage and the results were compared to dye penetration method.Materials and Method: The crowns of 21 extracted teeth were cut off at the CEJ level. After preparing the canals, the teeth were placed in tubes containing saline. They were divided randomly into 15 experimental cases; 3 positive and 3 negative controls. Positive controls were filled by single cone without sealer while the experimental and the negative control groups were filled by lateral technique. The coronal portion of gutta was removed and 9mm was left. The external surface of each tooth was coated with nail polish. Two millimeters of apical portion was immersed into 9ml of distilled water and 0.3ml of CuSO4 solution was injected into the coronal portion. After 2 days, copper sulfate was measured by an atomic absorption spectrophotometer. The teeth were then immersed in 2% methylene blue for 24 hours, sectioned and the extent of dye penetration was measured by a stereomicroscope.Results: The maximum and minimum recorded copper ion concentrations for the experimental group were 18.37 and 2.87ppm respectively. The maximum and minimum recorded dye penetrations for the experimental group were 8.5 and 3.5mm respectively. The statistical analysis, adopting paired samples test, showed poor correlation between average recorded results of two methods.Conclusion: Based on our results, there was no significant correlation between

  16. Synthesis of copper nanoparticles in polycarbonate by ion implantation

    Indian Academy of Sciences (India)

    Annu Sharma; Suman Bahniwal; Sanjeev Aggarwal; S Chopra; D Kanjilal

    2011-07-01

    Copper nanoparticles have been synthesized in polycarbonate by 75 KeV Cu– ion implantation with various doses ranging from 6.4 × 1015 to 1.6 × 1017 ions/cm2 with a beam current density of 800 nA/cm2. The composites formed were structurally characterized using Ultraviolet-Visible (UV-Visible) absorption spectroscopy. The appearance of particle plasmon resonance peak, characteristic of copper nanoparticles at 603 nm in absorption spectra of polycarbonate implanted to a dose of 1.6 × 1017 ions/cm2, indicates towards the formation of copper nanoparticles in polycarbonate. Transmission electron microscopy further confirms the formation of copper nanoparticles having size ∼ 3.15 nm. The formation of copper nanoparticles in the layers carbonized by Cu– implantation has been discussed. The synthesized copper-polycarbonate nanocomposite has been found to be more conducting than polycarbonate as ascertained using current–voltage characteristics.

  17. Release behavior of copper ion in a novel contraceptive composite.

    Science.gov (United States)

    Li, Juan; Suo, Jinping; Huang, Xunbin; Ye, Chang; Wu, Xiwang

    2007-09-01

    The universally used contraceptive method, the Cu-IUD, an effective contraceptive, is being increasingly used worldwide for family planning. To avoid abnormal bleeding, pain, partial and complete expulsion associated with the burst release of copper during the first few days, a novel cross-linked composite based on poly vinyl alcohol (PVA) that contains copper ions, but not metallic copper, was synthesized. PVA, well known for its good processability, high strength, long-term temperature and pH stability and biocompatibility, was used as the matrix material. The corrosion products and the release rate of copper ions after soaking in simulated body fluid (SBF) for different time spans were studied by environmental scanning electron microscopy, X-ray energy dispersive spectroscopy, X-ray diffraction and atomic absorption spectrophotometer. No significant change on time dependence for the release rate of copper ions in the composite compared with that of metallic copper was found. Moreover, no other new elements, such as P, Cl and Ca, appeared on the surface of the composite and no Cu(2)O formed after immersing in SBF for 90 days. Burst release of copper ions can be avoided by loading copper ions in this polymer material. Release channels would not be obstructed by the deposition of corrosion products and nearly all of the copper loaded in the composites could be an effective contraceptive.

  18. Characterization of copper resistant ciliates: Potential candidates for ...

    African Journals Online (AJOL)

    ... of copper resistant ciliates: Potential candidates for consortia of organisms used in bioremediation of wastewater. ... African Journal of Biotechnology ... Copper is one of such contaminant found in the wastewater of local industries.

  19. Evaluation of copper resistant bacteria from vineyard soils and mining waste for copper biosorption

    Directory of Open Access Journals (Sweden)

    R Andreazza

    2011-03-01

    Full Text Available Vineyard soils are frequently polluted with high concentrations of copper due application of copper sulfate in order to control fungal diseases. Bioremediation is an efficient process for the treatment of contaminated sites. Efficient copper sorption bacteria can be used for bioremoval of copper from contaminated sites. In this study, a total of 106 copper resistant bacteria were examined for resistance to copper toxicity and biosorption of copper. Eighty isolates (45 from vineyard Mollisol, 35 from Inceptisol were obtained from EMBRAPA (Empresa Brasileira de Pesquisa Agropecuária experimental station, Bento Gonçalves, RS, Brazil (29º09'53.92''S and 51º31'39.40''W and 26 were obtained from copper mining waste from Caçapava do Sul, RS, Brazil (30º29'43.48''S and 53'32'37.87W. Based on resistance to copper toxicity and biosorption, 15 isolates were identified by 16S rRNA gene sequencing. Maximal copper resistance and biosorption at high copper concentration were observed with isolate N2 which removed 80 mg L-1 in 24 h. Contrarily isolate N11 (Bacillus pumilus displayed the highest specific copper biosorption (121.82 mg/L/OD unit in 24 h. GenBank MEGABLAST analysis revealed that isolate N2 is 99% similar to Staphylococcus pasteuri. Results indicate that several of our isolates have potential use for bioremediation treatment of vineyards soils and mining waste contaminated with high copper concentration.

  20. Evaluation of copper resistant bacteria from vineyard soils and mining waste for copper biosorption.

    Science.gov (United States)

    Andreazza, R; Pieniz, S; Okeke, B C; Camargo, F A O

    2011-01-01

    Vineyard soils are frequently polluted with high concentrations of copper due application of copper sulfate in order to control fungal diseases. Bioremediation is an efficient process for the treatment of contaminated sites. Efficient copper sorption bacteria can be used for bioremoval of copper from contaminated sites. In this study, a total of 106 copper resistant bacteria were examined for resistance to copper toxicity and biosorption of copper. Eighty isolates (45 from vineyard Mollisol, 35 from Inceptisol) were obtained from EMBRAPA (Empresa Brasileira de Pesquisa Agropecuária) experimental station, Bento Gonçalves, RS, Brazil (29°09'53.92″S and 51°31'39.40″W) and 26 were obtained from copper mining waste from Caçapava do Sul, RS, Brazil (30°29'43.48″S and 53'32'37.87W). Based on resistance to copper toxicity and biosorption, 15 isolates were identified by 16S rRNA gene sequencing. Maximal copper resistance and biosorption at high copper concentration were observed with isolate N2 which removed 80 mg L(-1) in 24 h. Contrarily isolate N11 (Bacillus pumilus) displayed the highest specific copper biosorption (121.82 mg/L/OD unit in 24 h). GenBank MEGABLAST analysis revealed that isolate N2 is 99% similar to Staphylococcus pasteuri. Results indicate that several of our isolates have potential use for bioremediation treatment of vineyards soils and mining waste contaminated with high copper concentration.

  1. Two-step flash light sintering process for enhanced adhesion between copper complex ion/silane ink and a flexible substrate

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Eun-Beom; Joo, Sung-Jun [Department of Mechanical Convergence Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Ahn, Heejoon [Department of Organic and Nano Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Kim, Hak-Sung, E-mail: kima@hanyang.ac.kr [Department of Mechanical Convergence Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Institute of Nano Science and Technology, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2016-03-31

    A copper complex ion ink (including copper nanoparticles, a copper precursor and a silane coupling agent) was synthesized to enhance the adhesion between the copper pattern and a polyimide (PI) substrate. Oxygen plasma treatment was performed on the polyimide substrate to initiate a chemical reaction between the complex ion ink and the polyimide. Then, a two-step flash light sintering method (consisting of preheating and main sintering) was used to sinter the copper complex ion ink. The copper complex ion patterns were characterized as a function of the weight fraction of silane coupling agent using scanning electron microscopy (SEM), a four-point probe method and adhesion testing. In addition, a bending fatigue test was performed to evaluate the reliability of the conductive copper pattern under cyclic bending. The copper pattern fabricated with copper complex ion ink containing 3 wt% silane coupling agent exhibited the highest adhesion level (5B), the lowest resistivity (7.6 μΩ·cm) and a low resistance change (18%) after the bending fatigue test. The two-step sintering method used to enhance the adhesion between the copper complex ion ink and polyimide substrate was also studied using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). - Highlights: • The copper complex ion ink with copper nanoparticles and copper precursor was fabricated. • The copper complex ion ink was sintered by two-step flash light sintering method. • The sintered copper pattern exhibited the highest adhesion level (5B). • The resistivity of sintered copper pattern was 7.6 μΩ·cm.

  2. Measurement of Electron-Ion Relaxation in Warm Dense Copper

    Science.gov (United States)

    Cho, B. I.; Ogitsu, T.; Engelhorn, K.; Correa, A. A.; Ping, Y.; Lee, J. W.; Bae, L. J.; Prendergast, D.; Falcone, R. W.; Heimann, P. A.

    2016-01-01

    Experimental investigation of electron-ion coupling and electron heat capacity of copper in warm and dense states are presented. From time-resolved x-ray absorption spectroscopy, the temporal evolution of electron temperature is obtained for non-equilibrium warm dense copper heated by an intense femtosecond laser pulse. Electron heat capacity and electron-ion coupling are inferred from the initial electron temperature and its decrease over 10 ps. Data are compared with various theoretical models.

  3. Antimicrobial activity of different copper alloy surfaces against copper resistant and sensitive Salmonella enterica.

    Science.gov (United States)

    Zhu, Libin; Elguindi, Jutta; Rensing, Christopher; Ravishankar, Sadhana

    2012-05-01

    Copper has shown antibacterial effects against foodborne pathogens. The objective of this study was to evaluate the antibacterial activity of copper surfaces on copper resistant and sensitive strains of Salmonella enterica. Six different copper alloy coupons (60-99.9% copper) were tested along with stainless steel as the control. The coupons were surface inoculated with either S. Enteritidis or one of the 3 copper resistant strains, S. Typhimurium S9, S19 and S20; stored under various incubation conditions at room temperature; and sampled at various times up to 2 h. The results showed that under dry incubation conditions, Salmonella only survived 10-15 min on high copper content alloys. Salmonella on low copper content alloys showed 3-4 log reductions. Under moist incubation conditions, no survivors were detected after 30 min-2 h on high copper content alloys, while the cell counts decreased 2-4 logs on low copper content coupons. Although the copper resistant strains survived better than S. Enteritidis, they were either completely inactivated or survival was decreased. Copper coupons showed better antimicrobial efficacy in the absence of organic compounds. These results clearly show the antibacterial effects of copper and its potential as an alternative to stainless steel for selected food contact surfaces.

  4. Copper-resistant bacteria enhance plant growth and copper phytoextraction.

    Science.gov (United States)

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

    2013-01-01

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

  5. Uptake of copper ion by activated sludge and its bacterial community variation analyzed by 16S rDNA

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The effect and uptake of copper ion on SBR(sequence batch reactor) biological treatment system was studied in this paper. Special nutrient and powder activated carbon(PAC) additive were tested as uptake stimulation technique. Results showed that copper ion had higher effect on unacclimated activated sludge system than on acclimated one. The special nutrient adding could enhance the uptake of copper significantly, while PAC adding could improve the sludge settling and decrease the turbidity of effluent. The variation of bacterial community analyzed by 16S rDNA method showed the acclimation of copper could increase copper resistance species, and excess accumulation could cause some species diminish. It was confirmed that acclimation could improve the resistance and uptake ability of microorganism to heavy metal.

  6. [Atomic absorption spectrophotometry study of copper ion release by copper-bearing intrauterine devices].

    Science.gov (United States)

    Berthou, J; Chrétien, F C; Driguez, P A

    1998-11-01

    Copper release from copper-bearing IUD's was studied in vitro and in vivo using atomic absorption spectrophotometry in deionized water, normal saline solution and normal ovulatory cervical mucus. In these media, copper release from a 375 mm2 DIU occurs without latency, showing comparable amounts for identical time intervals. Daily copper release was shown to be respectively 8 and 11 times higher in cervical mucus and normal saline solution than in deionized water. Although copper ions are detectable in ovulatory cervical mucus under physiological conditions, the copper content appears 5 to 6 times higher in women bearing a copper IUD. Obviously, the copper amount is dependent on the copper exposed surface: the daily in vitro release from a 250 mm2 IUD is 18% inferior to that observed from a 375 mm2 model. In vivo, the daily copper release in ovulatory mucus of 380 or 200 mm2 IUD users is respectively 5 and 3.5 times higher than in controls.

  7. Proteomic Analysis of Drug-Resistant Mycobacteria: Co-Evolution of Copper and INH Resistance: e0127788

    National Research Council Canada - National Science Library

    Yuling Chen; Fan Yang; Zhongyuan Sun; Qingtao Wang; Kaixia Mi; Haiteng Deng

    2015-01-01

    .... To better understand the resistance mechanisms of mycobacteria to copper, we generated a copper-resistant strain of Mycobacterium smegmatis, mc2155-Cu from the selection of copper sulfate treated-bacteria...

  8. Evaluation of copper resistant bacteria from vineyard soils and mining waste for copper biosorption

    Science.gov (United States)

    Andreazza, R.; Pieniz, S.; Okeke, B.C.; Camargo, F.A.O

    2011-01-01

    Vineyard soils are frequently polluted with high concentrations of copper due application of copper sulfate in order to control fungal diseases. Bioremediation is an efficient process for the treatment of contaminated sites. Efficient copper sorption bacteria can be used for bioremoval of copper from contaminated sites. In this study, a total of 106 copper resistant bacteria were examined for resistance to copper toxicity and biosorption of copper. Eighty isolates (45 from vineyard Mollisol, 35 from Inceptisol) were obtained from EMBRAPA (Empresa Brasileira de Pesquisa Agropecuária) experimental station, Bento Gonçalves, RS, Brazil (29°09′53.92″S and 51°31′39.40″W) and 26 were obtained from copper mining waste from Caçapava do Sul, RS, Brazil (30°29′43.48″S and 53′32′37.87W). Based on resistance to copper toxicity and biosorption, 15 isolates were identified by 16S rRNA gene sequencing. Maximal copper resistance and biosorption at high copper concentration were observed with isolate N2 which removed 80 mg L−1 in 24 h. Contrarily isolate N11 (Bacillus pumilus) displayed the highest specific copper biosorption (121.82 mg/L/OD unit in 24 h). GenBank MEGABLAST analysis revealed that isolate N2 is 99% similar to Staphylococcus pasteuri. Results indicate that several of our isolates have potential use for bioremediation treatment of vineyards soils and mining waste contaminated with high copper concentration. PMID:24031606

  9. Copper as an antibacterial agent for human pathogenic multidrug resistant Burkholderia cepacia complex bacteria.

    Science.gov (United States)

    Ibrahim, Muhammad; Wang, Fang; Lou, Miao-miao; Xie, Guan-lin; Li, Bin; Bo, Zhu; Zhang, Gou-qing; Liu, He; Wareth, Abdul

    2011-12-01

    The Burkholderia cepacia complex (Bcc) consists of 17 closely related multidrug resistant bacterial species that are difficult to eradicate. Copper has recently gained attention as an antimicrobial agent because of its inhibitory effects on bacteria, yeast, and viruses. The objective of this study was to evaluate the antibacterial activity of copper surfaces and copper powder against members of the B. cepacia complex. The antibacterial activity of different copper surfaces was evaluated by incubating them with Bcc strain suspensions (5×10(7)cfu/ml). The bacterial survival counts were calculated and the data for various copper surfaces were compared to the data for stainless steel and polyvinylchloride, which were used as control surfaces. The antibacterial activity of copper powder was determined with the diffusimetrical technique and the zone of inhibition was evaluated with paper disks. A single cell gel electrophoresis assay, staining assays, and inductively coupled plasma mass spectroscopy were performed to determine the mechanism responsible for the bactericidal activity. The results showed a significant decrease in the viable bacterial count after exposure to copper surfaces. Moreover, the copper powder produced a large zone of inhibition and there was a significantly higher influx of copper ions into the bacterial cells that were exposed to copper surfaces compared to the controls. The present study demonstrates that metallic copper has an antibacterial effect against Bcc bacteria and that copper adversely affects the bacterial cellular structure, thus resulting in cell death. These findings suggest that copper could be utilized in health care facilities to reduce the bioburden of Bcc species, which may protect susceptible members of the community from bacterial infection.

  10. Copper(I) electrode function of two types of copper(II) ion-selective electrodes.

    Science.gov (United States)

    Neshkova, M; Sheytanov, H

    1985-08-01

    The response of two types of solid-state copper ion-selective electrodes with homogeneous membranes of CuAgSe and Cu(2-x)Se has been investigated in copper(I) solutions, prepared electrochemically by insitu generation from a copper anode in chloride medium. The selectivity coefficient K(pot)(Cu+, Cu(2+)) both types of electrodes has been determined. It is 10(-5.7) for the copper selenide sensor, and 10(-6.2) for the copper silver selenide one. These values are very close to that calculated for an exchange reaction proceeding on the electrode surface. The similarity in K(pot)(Cu+ ,Cu(2+)) values for different chalcogenidebased sensors suggests a common potential-generating mechanism. High chloride concentration does not interfere with the electrode response towards Cu(I), but distorts the electrode response to Cu(II).

  11. Ion-beam-induced modifications in the structural and electrical properties of copper oxide selenite nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Rana, Pallavi, E-mail: prana.phy@gmail.com; Chauhan, R.P.

    2015-04-15

    Highlights: •Nanowires were synthesized via template-assisted electrodeposition method. •Copper oxide selenite nanowires were irradiated with 160 MeV, Ni{sup +12} ion beam. •XRD confirmed no change in phase of irradiated nanowires. •Electrical resistivity of nanowires was found to decrease with the ion fluence. -- Abstract: Irradiation with swift heavy ions (SHIs) with energy in the MeV range is a unique tool for engineering the properties of materials. In this context, the objective of the present work is to study the conduction of charge carriers in pre- and post-ion-irradiated semiconducting nanowires. Copper oxide selenite nanowires were synthesized using a template-assisted electrodeposition technique from an aqueous solution of 0.8 M CuSO{sub 4}·5H{sub 2}O and 8 mM SeO{sub 2}. The synthesized nanowires were observed to have a monoclinic structure with linear I–V characteristics (IVC). The effect of irradiation with 160 MeV Ni{sup +12} ions on the properties of the copper oxide selenite nanowires was investigated for fluences varying from 10{sup 11} to 10{sup 13} ions/cm{sup 2}. XRD spectra confirmed no change in the phase of the swift-heavy-ion-irradiated nanowires, but a modification in the orientation of the planes was observed that depended on the ion fluence. The electrical resistivity of the semiconducting nanowires also varied with the ion fluence. Simultaneous irradiation-induced modifications to the electro-chemical potential gradient and the granular properties of the material may have been the origin of the alteration in the structural and electrical properties of the nanowires.

  12. Erosion of Copper Target Irradiated by Ion Beam

    CERN Document Server

    Polosatkin, S V; Grishnyaev, E S; Konstantinov, S G; Shoshin, A A

    2012-01-01

    Erosion of copper target irradiated by deuterium ion beam with ultimate fluence is studied. The target originally destined for neutron generation represents bulk copper substrate covered by 3-\\mum titanium layer. The target was irradiated by deuterium ion beam generated in Bayard-Alpert type ion source with energy of ions 17.5 keV/nuclear. Maximal fluence in the center of the target achieves 2.5x10^23atoms/cm^2. Measurements of the profile of irradiated target and estimation of fluence shows that physical sputtering is a dominating process that determines the target erosion Most interesting feature is growth of \\mum-size tadpole-shaped structures, localized in the cracks of the surface. RFA analysis of these structures showed extremely large (up to 60%at.) carbon content.

  13. Evaluation of Microscopic Degradation of Copper and Copper Alloy by Electrical Resistivity Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chung Seok [Hanyang University, Seoul (Korea, Republic of); Nahm, Seung Hoon [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of); Hyun, Chang Young [Seoul National University of Science and Technology, Seoul (Korea, Republic of)

    2010-10-15

    In the present study, the microscopic degradation of copper and copper and alloy subjected to cyclic deformation has been evaluated by the electrical resistivity measurement using the DC four terminal potential method. The copper (Cu) and copper alloy (Cu-35Zn), whose stacking fault energy is much different each other, were cyclically deformed to investigate the response of the electrical resistivity to different dislocation substructures. Dislocation cell substructure was developed in the Cu, while the planar array of dislocation structure was developed in the Cu-35Zn alloy increasing dislocation density with fatigue cycles. The electrical resistivity increased rapidly in the initial stage of fatigue deformation in both materials. Moreover, after the fatigue test it increased by about 7 % for the Cu and 6.5 % for the Cu-35Zn alloy, respectively. From these consistent results, it may be concluded that the dislocation cell structure responds to the electrical resistivity more sensitively than the planar array dislocation structure evolved during cyclic fatigue

  14. Seeding of silicon by copper ion implantation for selective electroless copper plating

    Energy Technology Data Exchange (ETDEWEB)

    Bhansali, S.; Sood, D.K.; Zmood, R.B. [Microelectronic and Materials Technology Centre, Royal Melbourne Institute of Technolgy, Melbourne, VIC (Australia)

    1993-12-31

    We report on the successful use of copper(self) ion implantation into silicon to seed the electroless plating of copper on silicon (100) surfaces. Copper ions have been implanted to doses of 5E14-6.4E16 ions/cm{sup 2} using a MEEVA ion implanter at extraction voltage of 40kV. Dose was varied in fine steps to determine the threshold dose of 2E15 Cu ions/cm{sup 2} for `seed` formation of copper films on silicon using a commercial electroless plating solution. Plated films were studied with Rutherford backscattering spectrometry, scanning electron microscopy, EDX and profilometry . The adhesion of films was measured by `scotch tape test`. The adhesion was found to improve with increasing dose. However thicker films exhibited rather poor adhesion and high internal stress. SEM results show that the films grow first as isolated islands which become larger and eventually impinge into a continuous film as the plating time is increased. (authors). 5 refs., 1 tab., 3 figs.

  15. Evolution of a Heavy Metal Homeostasis/Resistance Island Reflects Increasing Copper Stress in Enterobacteria

    OpenAIRE

    Staehlin, Benjamin M; Gibbons, John G.; Rokas, Antonis; O'Halloran, Thomas V.; Slot, Jason C.

    2016-01-01

    Copper homeostasis in bacteria is challenged by periodic elevation of copper levels in the environment, arising from both natural sources and human inputs. Several mechanisms have evolved to efflux copper from bacterial cells, including the cus (copper sensing copper efflux system), and pco (plasmid-borne copper resistance system) systems. The genes belonging to these two systems can be physically clustered in a Copper Homeostasis and Silver Resistance Island (CHASRI) on both plasmids and chr...

  16. Visual Observation of Dissolution of Copper Ions from a Copper Electrode

    Science.gov (United States)

    Ikemoto, Isao; Saitou, Kouichi

    2013-01-01

    During electrolysis, to visually observe the conversion of a metal to its cation, either the cation or its complex ion should have a distinct color while the electrolyte solution must be colorless and transparent. A demonstration is described in which copper is used as the electrodes and sodium polyacrylate (a superabsorbent polymer) solution is…

  17. Visual Observation of Dissolution of Copper Ions from a Copper Electrode

    Science.gov (United States)

    Ikemoto, Isao; Saitou, Kouichi

    2013-01-01

    During electrolysis, to visually observe the conversion of a metal to its cation, either the cation or its complex ion should have a distinct color while the electrolyte solution must be colorless and transparent. A demonstration is described in which copper is used as the electrodes and sodium polyacrylate (a superabsorbent polymer) solution is…

  18. Mechanistic basis for overcoming platinum resistance using copper chelating agents.

    Science.gov (United States)

    Liang, Zheng D; Long, Yan; Tsai, Wen-Bin; Fu, Siqing; Kurzrock, Razelle; Gagea-Iurascu, Mihai; Zhang, Fan; Chen, Helen H W; Hennessy, Bryan T; Mills, Gordon B; Savaraj, Niramol; Kuo, Macus Tien

    2012-11-01

    Platinum-based antitumor agents are widely used in cancer chemotherapy. Drug resistance is a major obstacle to the successful use of these agents because once drug resistance develops, other effective treatment options are limited. Recently, we conducted a clinical trial using a copper-lowering agent to overcome platinum drug resistance in ovarian cancer patients and the preliminary results are encouraging. In supporting this clinical study, using three pairs of cisplatin (cDDP)-resistant cell lines and two ovarian cancer cell lines derived from patients who had failed in platinum-based chemotherapy, we showed that cDDP resistance associated with reduced expression of the high-affinity copper transporter (hCtr1), which is also a cDDP transporter, can be preferentially resensitized by copper-lowering agents because of enhanced hCtr1 expression, as compared with their drug-sensitive counterparts. Such a preferential induction of hCtr1 expression in cDDP-resistant variants by copper chelation can be explained by the mammalian copper homeostasis regulatory mechanism. Enhanced cell-killing efficacy by a copper-lowering agent was also observed in animal xenografts bearing cDDP-resistant cells. Finally, by analyzing a public gene expression dataset, we found that ovarian cancer patients with elevated levels of hCtr1 in their tumors, but not ATP7A and ATP7B, had more favorable outcomes after platinum drug treatment than those expressing low hCtr1 levels. This study reveals the mechanistic basis for using copper chelation to overcome cDDP resistance in clinical investigations.

  19. Proteomic analysis of the copper resistance of Streptococcus pneumoniae.

    Science.gov (United States)

    Guo, Zhong; Han, Junlong; Yang, Xiao-Yan; Cao, Kun; He, Ke; Du, Gaofei; Zeng, Guandi; Zhang, Liang; Yu, Guangchuang; Sun, Zhenghua; He, Qing-Yu; Sun, Xuesong

    2015-03-01

    Streptococcus pneumoniae is a Gram-positive bacterial pathogen causing a variety of diseases, including otitis media, bacteraemia and meningitis. Although copper is an essential trace metal for bacterial growth, high intracellular levels of free-copper are toxic. Copper resistance has emerged as an important virulence determinant of microbial pathogens. In this study, we determined the minimum inhibition concentration of copper for the growth inhibition of S. pneumoniae. Two-dimensional-electrophoresis coupled with mass spectrometry was applied to identify proteins involved in copper resistance of S. pneumoniae. In total, forty-four proteins with more than 1.5-fold alteration in expression (p < 0.05) were identified. Quantitative reverse transcription PCR was used to confirm the proteomic results. Bioinformatics analysis showed that the differentially expressed proteins were mainly involved in the cell wall biosynthesis, protein biosynthesis, purine biosynthesis, pyrimidine biosynthesis, primary metabolic process, and the nitrogen compound metabolic process. Many up-regulated proteins in response to the copper treatment directly or indirectly participated in the cell wall biosynthesis, indicating that the cell wall is a critical determinant in copper resistance of S. pneumoniae.

  20. Copper oxide resistive switching memory for e-textile

    Directory of Open Access Journals (Sweden)

    Jin-Woo Han

    2011-09-01

    Full Text Available A resistive switching memory suitable for integration into textiles is demonstrated on a copper wire network. Starting from copper wires, a Cu/CuxO/Pt sandwich structure is fabricated. The active oxide film is produced by simple thermal oxidation of Cu in atmospheric ambient. The devices display a resistance switching ratio of 102 between the high and low resistance states. The memory states are reversible and retained over 107 seconds, with the states remaining nondestructive after multiple read operations. The presented device on the wire network can potentially offer a memory for integration into smart textile.

  1. Copper oxide resistive switching memory for e-textile

    Science.gov (United States)

    Han, Jin-Woo; Meyyappan, M.

    2011-09-01

    A resistive switching memory suitable for integration into textiles is demonstrated on a copper wire network. Starting from copper wires, a Cu/CuxO/Pt sandwich structure is fabricated. The active oxide film is produced by simple thermal oxidation of Cu in atmospheric ambient. The devices display a resistance switching ratio of 102 between the high and low resistance states. The memory states are reversible and retained over 107 seconds, with the states remaining nondestructive after multiple read operations. The presented device on the wire network can potentially offer a memory for integration into smart textile.

  2. Characterization of copper-resistant rhizosphere bacteria from Avena sativa and Plantago lanceolata for copper bioreduction and biosorption.

    Science.gov (United States)

    Andreazza, Robson; Okeke, Benedict C; Pieniz, Simone; Camargo, Flávio A O

    2012-04-01

    Copper is a toxic heavy metal widely used to microbial control especially in agriculture. Consequently, high concentrations of copper residues remain in soils selecting copper-resistant organisms. In vineyards, copper is routinely used for fungi control. This work was undertaken to study copper resistance by rhizosphere microorganisms from two plants (Avena sativa L. and Plantago lanceolata L.) common in vineyard soils. Eleven rhizosphere microorganisms were isolated, and four displayed high resistance to copper. The isolates were identified by 16S rRNA gene sequence analysis as Pseudomonas putida (A1), Stenotrophomonas maltophilia (A2) and Acinetobacter sp. (A6), isolated from Avena sativa rhizosphere, and Acinetobacter sp. (T5), isolated from Plantago lanceolata rhizosphere. The isolates displayed high copper resistance in the temperature range from 25°C to 35°C and pH in the range from 5.0 to 9.0. Pseudomonas putida A1 resisted as much as 1,000 mg L(-1) of copper. The isolates showed similar behavior on copper removal from liquid medium, with a bioremoval rate of 30% at 500 mg L(-1) after 24 h of growth. Speciation of copper revealed high copper biotransformation, reducing Cu(II) to Cu(I), capacity. Results indicate that our isolates are potential agents for copper bioremoval and bacterial stimulation of copper biosorption by Avena sativa and Plantago lanceolata.

  3. Removal of copper ions from electroplating rinse water using electrodeionization

    Institute of Scientific and Technical Information of China (English)

    Xiao FENG; Jun-song GAO; Zu-cheng WU

    2008-01-01

    An improved configuration of the membrane stack was adopted in the electrodeionization (EDI)cell to prevent precipitation of bivalent metal hydroxide during the running.The operational parameters that influenced the removal of copper ions from the dilute solution were optimized.The result showed that a moderate decrease in the inlet pH value and a moderate increase in the applied voltage could achieve a better removaI effect.The steady process of electroplating wastewater treatment could be achieved with a removal efficiency ofmore than 99.5%and an enrichment factor of 5~14.The concentration of copper in purlfled water was less than 0.23 mg/L.This demonstrated the applicability of recovering heavy metal ions and purifled water from electroplating effluent for industrial reuse.

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

    Science.gov (United States)

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

    2017-05-12

    Copper oxide nanoparticles (CuO NPs) are being increasingly applied in the industry which results inevitably in the release of these materials into the hydrosphere. In this study, simulated waste-activated sludge experiments were conducted to investigate the effects of Copper Oxide NPs at concentrations of 0.1, 1, 10 and 50 mg/L and to compare it with its ionic counterpart (CuSO4). It was found that 0.1 mg/L of CuO NPs had negligible effects on Chemical Oxygen Demand (COD) and ammonia removal. However, the presence of 1, 10 and 50 mg/L of CuO NPs decreased COD removal from 78.7% to 77%, 52.1% and 39.2%, respectively (P copper ions were more toxic towards microorganisms compared to CuO NPs. CuO NPs were removed effectively (72-93.2%) from wastewater due to a greater biosorption capacity of CuO NPs onto activated sludge, compared to the copper ions (55.1-83.4%). The SEM images clearly showed the accumulation and adsorption of CuO NPs onto activated sludge. The decrease in Live/dead ratio after 5 h of exposure of CuO NPs and Cu(2+) indicated the loss of cell viability in sludge flocs.

  5. Incorporation of copper ions into crystals of T2 copper-depleted laccase from Botrytis aclada

    Energy Technology Data Exchange (ETDEWEB)

    Osipov, E. M., E-mail: e.m.osipov@gmail.com [A. N. Bach Institute of Biochemistry, Leninsky pr. 33, Moscow 119071 (Russian Federation); Polyakov, K. M. [A. N. Bach Institute of Biochemistry, Leninsky pr. 33, Moscow 119071 (Russian Federation); Engelhardt Institute of Molecular Biology, Vavilova str. 32, Moscow 119991 (Russian Federation); Tikhonova, T. V. [A. N. Bach Institute of Biochemistry, Leninsky pr. 33, Moscow 119071 (Russian Federation); Kittl, R. [BOKU – University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Wien (Austria); Dorovatovskii, P.V. [RSC ‘Kurchatov Institute’, Acad. Kurchatov sq. 1, Moscow 123182 (Russian Federation); Shleev, S. V.; Popov, V. O. [A. N. Bach Institute of Biochemistry, Leninsky pr. 33, Moscow 119071 (Russian Federation); RSC ‘Kurchatov Institute’, Acad. Kurchatov sq. 1, Moscow 123182 (Russian Federation); Ludwig, R. [BOKU – University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Wien (Austria)

    2015-11-18

    The restoration of the native form of laccase from B. aclada from the type 2 copper-depleted form of the enzyme was investigated. Copper ions were found to be incorporated into the active site after soaking the depleted enzyme in a Cu{sup +}-containing solution. Laccases belong to the class of multicopper oxidases catalyzing the oxidation of phenols accompanied by the reduction of molecular oxygen to water without the formation of hydrogen peroxide. The activity of laccases depends on the number of Cu atoms per enzyme molecule. The structure of type 2 copper-depleted laccase from Botrytis aclada has been solved previously. With the aim of obtaining the structure of the native form of the enzyme, crystals of the depleted laccase were soaked in Cu{sup +}- and Cu{sup 2+}-containing solutions. Copper ions were found to be incorporated into the active site only when Cu{sup +} was used. A comparative analysis of the native and depleted forms of the enzymes was performed.

  6. Preparation and characterization of microgels sensitive toward copper II ions.

    Science.gov (United States)

    Muratalin, Marat; Luckham, Paul F

    2013-04-15

    An emulsion polymerization technique has been used to prepare chemically crosslinked microgels in aqueous suspension that are sensitive to the presence of copper ions. Poly(N-isopropylacrylamide) (PNIPAM) was copolymerized with different amounts of 1-vinylimidazole (VI), and the resultant microgels exhibited multi-responsive behavior being sensitive to changes in temperature, pH and to the presence of metal ions, particularly copper. These swelling properties of the microgel particles were characterized using dynamic light scattering (DLS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The effect of temperature showed that the microgel particles shrunk continuously as the temperature was raised, up to a temperature of 50°C, and the volume phase transition temperature, VPTT, has been shifted to higher temperatures (in the range of 35-45°C) compared to pure PNIPAM microgels where the VPTT≈30-35°C. The particle size of these microgels was also investigated as a function of pH; the microgel particles became swollen at low pH and collapsed at high pH, due to the ionization of the VI component of the microgels. Most interesting, however, was the effect of the copper ion concentration in solution. The PNIPAM-co-VI microgels were found to swell with increasing concentration of Cu(2+) up to 0.3g/l of Cu(2+) due to adsorption of the cations inside the particle, which leads to charging up the internal phase of the microgel. However, at higher concentrations of added copper (II) ions, the binding forces of complexation lead to conformational changes to the microgel resulting in weaker polymer-solvent interaction and consequential shrinkage again of the polymer. In addition, the copper (II) uptake was calculated, and the uptake was found to be well described by the Langmuir adsorption isotherm, with up to 2g of copper II being taken up by 1g of microgel. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Reducing Grain-Boundary Resistivity of Copper Nanowires by Doping

    Science.gov (United States)

    César, Mathieu; Gall, Daniel; Guo, Hong

    2016-05-01

    The resistance of doped single grain boundaries (GBs) in copper is calculated from first principles and systematically compared to its pure single GB equivalent. As a first step, a state-of-the-art ab initio method is used to calculate the resistivity of doped bulk copper for 16 doping elements at concentration 1 at. %. Results are in qualitatively excellent and quantitatively reasonable agreement with the corresponding experimental data, and allow us to determine Ag, Zn, Mg, Pd, Al, and In as best candidates for GB doping. These atoms have a minimal impact on the bulk resistivity, while they also conform to a set of established criteria for alloying with copper. Then, the specific resistivity of six twin GBs is determined for these elements over a wide spectrum of doping concentrations for the submonolayer and the monolayer GB complexions. Reduced resistivity is observed for Zn, Mg, Al, In, and other elements in two high-Σ GBs, and is qualitatively related to the segregation enthalpy as well as to a low number of empty states around the Fermi energy in the boundary plane region of the GB. The results indicate the possibility for a reduced net resistivity in copper interconnects by GB doping.

  8. Fundamental features of copper ion precipitation using sulfide as a precipitant in a wastewater system.

    Science.gov (United States)

    Choi, Jung-Yoon; Kim, Dong-Su; Lim, Joong-Yeon

    2006-01-01

    We have investigated the precipitation features of copper ion using sulfide as a precipitant by varying the mole ratio of sulfide to copper ion, pH, temperature and the kind and concentration of complexing agent. In the precipitation of copper ion by sulfide, sludge is produced as cupric sulfide; thus, there is a possibility for its recycled use in photochemical and ceramic processes. When the ratio of the concentration of copper ion to sulfide was increased to more than 1.0, the extent of precipitation was very high. As the ratio was increased, nucleation time was decreased and crystal growth rate was raised. The higher the pH, the greater the amount of precipitated copper ion due to lowered solubility of cupric sulfide. When temperature changed from 25 degrees C to 55 degrees C, the precipitation of copper ion was increased a little. On the basis of estimated thermodynamic parameters such as Gibbs free energy and enthalpy, the precipitation reaction was spontaneous and endothermic. The precipitation of copper ion was lowered in the presence of complexing agent and it was affected by the stability of the copper complex. The feasibility test for the application of precipitation treatment to actual wastewater containing copper ion showed, although there was a little decrease in the removal of copper, the precipitation extent of copper was higher than 90% compared with that for artificial wastewater.

  9. Electrochemical Behavior of Nano-grained Pure Copper in Dilute Alkaline Solution with Chloride Ion Trace

    Science.gov (United States)

    Fattah-Alhosseini, Arash; Imantalab, Omid; Attarzadeh, Farid Reza

    2016-10-01

    Effect of nano-grained structure on the interface behavior of pure copper in 0.01M KOH solution with chloride ion trace is investigated by various electrochemical techniques. Nano-grained structure was achieved by accumulative roll bonding (ARB) technique. Before any electrochemical measurements, microstructure was evaluated by means of optical microscopy and transmission electron microscopy (TEM). TEM observations showed that nano-grains (with an average size of below 100 nm) appeared after eight passes of ARB. Polarization curves revealed that increasing chloride ion concentration leads to a decrease in the corrosion and pitting potentials of both annealed and nano-grained pure copper samples. Electrochemical impedance spectroscopy revealed that chloride ion trace lowers passive film resistance and charge-transfer resistance in both annealed and nano-grained samples. Mott-Schottky analysis showed that the surface films formed on annealed and nano-grained samples in KOH solution with and without NaCl addition are of p-type semiconducting behavior. Moreover, this analysis showed that the acceptor density increases by increasing chloride ion concentration.

  10. Disulfiram and Copper Ions Kill Mycobacterium tuberculosis in a Synergistic Manner.

    Science.gov (United States)

    Dalecki, Alex G; Haeili, Mehri; Shah, Santosh; Speer, Alexander; Niederweis, Michael; Kutsch, Olaf; Wolschendorf, Frank

    2015-08-01

    Tuberculosis is a severe disease affecting millions worldwide. Unfortunately, treatment strategies are hampered both by the prohibitively long treatment regimen and the rise of drug-resistant strains. Significant effort has been expended in the search for new treatments, but few options have successfully emerged, and new treatment modalities are desperately needed. Recently, there has been growing interest in the synergistic antibacterial effects of copper ions (Cu(II/I)) in combination with certain small molecular compounds, and we have previously reported development of a drug screening strategy to harness the intrinsic bactericidal properties of Cu(II/I). Here, we describe the copper-dependent antimycobacterial properties of disulfiram, an FDA-approved and well-tolerated sobriety aid. Disulfiram was inhibitory to mycobacteria only in the presence of Cu(II/I) and exerted its bactericidal activity well below the active concentration of Cu(II/I) or disulfiram alone. No other physiologically relevant bivalent transition metals (e.g., Fe(II), Ni(II), Mn(II), and Co(II)) exhibited this effect. We demonstrate that the movement of the disulfiram-copper complex across the cell envelope is porin independent and can inhibit intracellular protein functions. Additionally, the complex is able to synergistically induce intracellular copper stress responses significantly more than Cu(II/I) alone. Our data suggest that by complexing with disulfiram, Cu(II/I) is likely allowed unfettered access to vulnerable intracellular components, bypassing the normally sufficient copper homeostatic machinery. Overall, the synergistic antibacterial activity of Cu(II/I) and disulfiram reveals the susceptibility of the copper homeostasis system of Mycobacterium tuberculosis to chemical attacks and establishes compounds that act in concert with copper as a new class of bacterial inhibitors.

  11. COPPER RESISTANT STRAIN CANDIDA TROPICALIS RomCu5 INTERACTION WITH SOLUBLE AND INSOLUBLE COPPER COMPOUNDS

    Directory of Open Access Journals (Sweden)

    Ie. P. Prekrasna

    2015-10-01

    Full Text Available The focus of the study was interaction of Candida tropicalis RomCu5 isolated from highland Ecuador ecosystem with soluble and insoluble copper compounds. Strain C. tropicalis RomCu5 was cultured in a liquid medium of Hiss in the presence of soluble (copper citrate and CuCl2 and insoluble (CuO and CuCO3 copper compounds. The biomass growth was determined by change in optical density of culture liquid, composition of the gas phase was measured on gas chromatograph, redox potential and pH of the culture fluid was defined potentiometrically. The concentration of soluble copper compounds was determined colorimetrically. Maximal permissible concentration of Cu2+ for C. tropicalis RomCu5 was 30 000 ppm of Cu2+ in form of copper citrate and 500 ppm of Cu2+ in form of CuCl2. C. tropicalis was metabolically active at super high concentrations of Cu2+, despite the inhibitory effect of Cu2+. C. tropicalis immobilized Cu2+ in the form of copper citrate and CuCl2 by it accumulation in the biomass. Due to medium acidification C. tropicalis dissolved CuO and CuCO3. High resistance of C. tropicalis to Cu2+ and ability to interact with soluble and insoluble copper compounds makes it biotechnologically perspective.

  12. Copper resistance in Pseudomonas syringae mediated by periplasmic and outer membrane proteins.

    OpenAIRE

    Cha, J S; Cooksey, D A

    1991-01-01

    Copper-resistant strains of Pseudomonas syringae pathovar tomato accumulate copper and develop blue colonies on copper-containing media. Three of the protein products of the copper-resistance operon (cop) were characterized to provide an understanding of the copper-resistance mechanism and its relationship to copper accumulation. The Cop proteins, CopA (72 kDa), CopB (39 kDa), and CopC (12 kDa), were produced only under copper induction. CopA and CopC were periplasmic proteins and CopB was an...

  13. Copper ions inactivate S-ade-nosylhomocysteine hydrolase

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    S-adenosylhomocysteine (AdoHcy) hydrolase isan enzyme that regulates biomethylation and some otherphysiological processes. Recombinant AdoHcy hydrolase wasoverexpressed in E. coli JM109 and purified with ion ex-change and gel filtration chromatographies. The effects ofcopper ions (Cu2+) on the activity of AdoHcy hydrolase wereinvestigated and the results showed that Cu2+ inhibited theenzyme's activity by a concentration and time-dependentprocess. The inhibition constant (Ki) and the apparent rateconstant (kapp) were calculated to be (14 + 4) nmol @ L-1 and(1.08 + 0.15) min-1, respectively. The existence of the naturalsubstrate Ado could to some extent prevent Cu2+ from inac-tivating the enzyme, suggesting that copper ions possiblycould compete with the natural substrate on enzyme's sub-strate binding site. Further studies on the mechanism of in-hibition are being carried out.

  14. The role of copper ions in pathophysiology and fluorescent sensors for the detection thereof.

    Science.gov (United States)

    Verwilst, Peter; Sunwoo, Kyoung; Kim, Jong Seung

    2015-04-04

    Copper ions are indispensible to life and maintaining tight control over the homeostasis of copper ions in the body is a prerequisite to sustaining health. Aberrations in normal copper levels, both systemic as well as on a tissue or cellular scale, are implicated in a wide range of diseases, such as Menkes disease, Wilson's disease, Alzheimer's disease, Parkinson's disease and transmissible spongiform encephalopathy (prion diseases). The current understanding of how copper influences these diseases is described. The field of fluorescent copper sensors both functioning via a reaction based mechanism as well as by directly binding copper ions has known an inflation in recent years, and the importance of this field to elucidating the role of copper in cell biology is pointed out. Progress in these tightly interwoven fields has resulted in a better understanding of a number of diseases related to copper imbalances and current developments might open the path for novel and innovating therapies to address these diseases.

  15. Effect of copper ions implantation on the corrosion behavior of ZIRLO alloy in 1 mol/L H2SO4

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In order to study the effect of copper ion implantation on the aqueous corrosion behavior of ZIRLO alloy, specimens were implanted with copper ions with fluences ranging from l×l016 to 1×1017 ions/cm2, using a metal vapor vacuum arc source (MEVVA) at an extraction voltage of 40 kV.The valence states and depth distributions of elements in the surface layer of the samples were analyzed by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES), respectively.Glancing angle X-ray diffraction(GAXRD) was employed to examine the phase transformation due to the copper ion implantation.The potentiodynamic polarization technique was used to evaluate the aqueous corrosion resistance of implanted ZIRLO alloy in a l mol/L H2SO4 solution.It was found that a significant improvement was achieved in the aqueous corrosion resistance of ZIRLO alloy implanted with copper ions when the fluence is 5×1016 ions/cm2.When the fluence is l×l016 or l×l017 ions/cm2, the corrosion resistance of implanted samples was bad..Finally, the mechanism of the corrosion behavior of copper-implanted ZIRLO alloy was discussed.

  16. Removal of adsorbent particles od copper ions by Jet flotation; Remocion de particulas adsorbentes de iones cobre por flotacion Jet

    Energy Technology Data Exchange (ETDEWEB)

    Santander, M.; Tapia, P.; Pavez, O.; Valderrama, L.; Guzman, D.

    2009-07-01

    The present study shows the results obtained on the removal of copper ions from synthetic effluents by using the adsorbent particles flotation technique (APF) in a Jet flotation cell (Jameson type). In a typical experimental run, a mineral with high quartz content was used as adsorbent particles in the adsorption and flotation experiments, to determine optimal pH conditions, adsorbent particles concentration; flotation reagents dosage and air/effluent flow ratio for applying in the Jet cell to maximize the efficiency of copper ions adsorptions and the removal of particles adsorbents containing the absorbed copper ions. The results indicate the at pH>7 and at adsorbent particles concentration of 2 kg.m{sup -}3, 99% of copper ions is adsorbed and, when the air/effluent flow ratio applied in the Jet cell is 0,2, 98% of absorbent particles containing the adsorbed copper ions is removed. (Author) 39 refs.

  17. Chloride-Ion Penetrability and Mechanical Analysis of High Strength Concrete with Copper Slag

    Directory of Open Access Journals (Sweden)

    Savaş Erdem

    2014-05-01

    Full Text Available The use of waste materials and industrial by-products in high-strength concrete could increase the sustainability of the construction industry. In this study, the potential of using copper slag as coarse aggregate in high-strength concrete was experimentally investigated. The effects of replacing gravel coarse aggregate by copper slag particles on the compressive strength, chloride ion- migration, water permeability and impact resistance of high-strength concretes were evaluated. Incorporating copper slag coarse particles resulted in a compressive strength increase of about 14 % on average partly due to the low Ca/Si ratio through the interface area of this concrete (more homogenous internal structure as confirmed by the energy dispersive X-ray micro chemical analysis. It was also found that the copper slag high-strength concrete provided better ductility and had much greater load carrying capacity compared to gravel high-strength concrete under dynamic conditions. Finally, it was observed that in comparison to the high strength concrete with slag, the chloride migration coefficient from non-steady state migration was approximately 30 % greater in the gravel high-strength concrete.

  18. The Mechanism of the Copper Ion Catalyzed Autoxidation of Cysteine in Alkaline Medium

    NARCIS (Netherlands)

    Koningsberger, D.C.; Zwart, J.; Wolput, J.H.M.C. van

    1981-01-01

    Quantitative e.s.r. measurements carried out during the copper catalysed alkaline autoxidation of cysteine show that the Cu(II)-dicysteine complex represents almost the total amount of copper. Only a small fraction (<2%) of the copper ions might be present in a state which is not detectable by e.s.r

  19. Texture coefficient analysis of ion beam irradiated copper nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Rana, Pallavi, E-mail: prana.phy@gmail.com; Chaudhary, Ritika, E-mail: chauhanrpc@gmail.com; Chauhan, R. P. [Department of Physics, National Institute of Technology, Kurukshetra-136119 (India)

    2016-05-23

    Radiation may deteriorate physical properties of the materials and leave negative as well as positive impacts especially on crystalline materials. The energy deposited by ions to the grains and grain boundaries could also influence other properties of grains like: strain, reflection of charge carriers from grain boundaries, in addition to their grain size and orientation. The intensity of a peak in the XRD spectra is the direct reflection of orientation of a miller plane in the crystal. The increased intensity symbolizes the crystalline behavior due to defects annealing, while decreased intensity portray the defects formation and slender amorphisation. Orientation distribution function is a probability distribution function that quantified the texture of a polycrystalline material. The coefficients of harmonic expansion of orientation distribution function is the measurement of the texture coefficient ‘TC’. This study focused on the investigation of effect of ion beam irradiation on the preffered orientation of the planes of copper nanowires.

  20. Micronized Copper Wood Preservatives: Efficacy of Ion, Nano, and Bulk Copper against the Brown Rot Fungus Rhodonia placenta.

    Directory of Open Access Journals (Sweden)

    Chiara Civardi

    Full Text Available Recently introduced micronized copper (MC formulations, consisting of a nanosized fraction of basic copper (Cu carbonate (CuCO3·Cu(OH2 nanoparticles (NPs, were introduced to the market for wood protection. Cu NPs may presumably be more effective against wood-destroying fungi than bulk or ionic Cu compounds. In particular, Cu- tolerant wood-destroying fungi may not recognize NPs, which may penetrate into fungal cell walls and membranes and exert their impact. The objective of this study was to assess if MC wood preservative formulations have a superior efficacy against Cu-tolerant wood-destroying fungi due to nano effects than conventional Cu biocides. After screening a range of wood-destroying fungi for their resistance to Cu, we investigated fungal growth of the Cu-tolerant fungus Rhodonia placenta in solid and liquid media and on wood treated with MC azole (MCA. In liquid cultures we evaluated the fungal response to ion, nano and bulk Cu distinguishing the ionic and particle effects by means of the Cu2+ chelator ammonium tetrathiomolybdate (TTM and measuring fungal biomass, oxalic acid production and laccase activity of R. placenta. Our results do not support the presence of particular nano effects of MCA against R. placenta that would account for an increased antifungal efficacy, but provide evidence that attribute the main effectiveness of MCA to azoles.

  1. SETUP AND PERFORMANCE OF THE RHIC INJECTOR ACCELERATORS FOR THE 2005 RUN WITH COPPER IONS.

    Energy Technology Data Exchange (ETDEWEB)

    AHRENS, L.; ALESSI, J.; GARDNER, C.J.

    2005-05-16

    Copper ions for the 2005 run [1] of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) are accelerated in the Tandem, Booster and AGS prior to injection into RHIC. The setup and performance of these accelerators with copper are reviewed in this paper.

  2. Investigation of peptide based surface functionalization for copper ions detection using an ultrasensitive mechanical microresonator

    DEFF Research Database (Denmark)

    Cagliani, Alberto; Fischer, Lee MacKenzie; Rasmussen, Jakob Lyager

    2011-01-01

    In the framework of developing a portable label-free sensor for multi arrayed detection of heavy metals in drinking water, we present a mechanical resonator-based copper ions sensor, which uses a recently synthesized peptide Cysteine–Glycine–Glycine–Histidine (CGGH) and the l-Cysteine (Cys) peptide...... devices to detect a concentration of 10μM of copper in water, we regenerate the surface by removing the copper ions from the functionalization layer using EDTA....

  3. Biosorption of copper (II) ions from synthetic aqueous solutions by drying bed activated sludge

    Energy Technology Data Exchange (ETDEWEB)

    Benaissa, H., E-mail: ho_benaissa@yahoo.fr [Laboratory of Sorbent Materials and Water Treatment, Department of Chemistry, Faculty of Sciences, University of Tlemcen, P.O. Box 119, 13000 Tlemcen (Algeria); Elouchdi, M.A. [Laboratory of Sorbent Materials and Water Treatment, Department of Chemistry, Faculty of Sciences, University of Tlemcen, P.O. Box 119, 13000 Tlemcen (Algeria)

    2011-10-30

    Highlights: {yields} Dried activated sludge has been investigated for the removal of copper ions from aqueous synthetic solutions, in batch conditions. {yields} Copper uptake was time contact, initial copper concentration, initial pH solution and copper salt type dependent. {yields} Maximum copper uptake obtained was q{sub m} = 62.50 mg/g (0.556 mmol/g) under the investigated experimental conditions. - Abstract: In the present work, the usefulness of dried activated sludge has been investigated for the removal of copper ions from synthetic aqueous solutions. Kinetic data and equilibrium sorption isotherm were measured in batch conditions. The influence of some parameters such as: contact time, initial copper concentration, initial pH of solution and copper salt nature on copper biosorption kinetics has been studied. Copper uptake was time contact, initial copper concentration, initial pH solution and copper salt type dependent. Maximum copper sorption was found to occur at initial pH 5. Two simplified kinetic models including a first-order rate equation and a pseudo second-order rate equation were selected to describe the biosorption kinetics. The process followed a pseudo second-order rate kinetics. The process mechanism was found to be complex, consisting of external mass transfer and intraparticle mass transfer diffusion. Copper biosorption process was particle-diffusion-controlled, with some predominance of some external mass transfer at the initial stages for the different experimental parameters studied. Langmuir and Freundlich models were used to describe sorption equilibrium data at natural pH of solution. Results indicated that the Langmuir model gave a better fit to the experimental data than the Freundlich model. Maximum copper uptake obtained was q{sub m} = 62.50 mg/g (0.556 mmol/g) under the investigated experimental conditions. Scanning electron microscopy coupled with X-ray energy dispersed analysis for copper-equilibrated dried activated sludge

  4. Correlation between Copper Ion Concentration in Cervical Mucus and Fllbrinolytic Activity in Menstrual Blood in Copper-releasiag IUD Users

    Institute of Scientific and Technical Information of China (English)

    林建华; 潘家骧; 严隽鸿

    1993-01-01

    In the present study, 44 women using TCu220c-IUD or inert-IUD were asked to make follow-ups before insertion and at the 1st., 3rd., 6th, 9th and 12th month after insertion The mean menstrual blood loss, the fibrinalytic activity including the activation of tissue-plasminogen activator (t-PA) and the amount of plasminogen PIG) and fibrinogen-fibrin degradation products (FDP) in menstrual blood and the copper ion concentration in cervical mucus were determined. The correlation between the copper ion concentration and the fibrinalytic activity was considered. It was found that the change of the copper ion concentration was positively correlated with that of the activition of t-PA and the amount of FDP. On the contrary, the change ofthe copper ion concentration was inversely related to the change of PLG value. It is concluded that the high copper ion level can enhance the activation of fibrinolytic system in human endometrium and induce the increase of menorrhagia.

  5. Efficient electron-induced removal of oxalate ions and formation of copper nanoparticles from copper(II oxalate precursor layers

    Directory of Open Access Journals (Sweden)

    Kai Rückriem

    2016-06-01

    Full Text Available Copper(II oxalate grown on carboxy-terminated self-assembled monolayers (SAM using a step-by-step approach was used as precursor for the electron-induced synthesis of surface-supported copper nanoparticles. The precursor material was deposited by dipping the surfaces alternately in ethanolic solutions of copper(II acetate and oxalic acid with intermediate thorough rinsing steps. The deposition of copper(II oxalate and the efficient electron-induced removal of the oxalate ions was monitored by reflection absorption infrared spectroscopy (RAIRS. Helium ion microscopy (HIM reveals the formation of spherical nanoparticles with well-defined size and X-ray photoelectron spectroscopy (XPS confirms their metallic nature. Continued irradiation after depletion of oxalate does not lead to further particle growth giving evidence that nanoparticle formation is primarily controlled by the available amount of precursor.

  6. Copper ion-exchanged channel waveguides optimization for optical trapping.

    Science.gov (United States)

    Reshak, A H; Khor, K N; Shahimin, M M; Murad, S A Z

    2013-08-01

    Optical trapping of particles has become a powerful non-mechanical and non-destructive technique for precise particle positioning. The manipulation of particles in the evanescent field of a channel waveguide potentially allows for sorting and trapping of several particles and cells simultaneously. Channel waveguide designs can be further optimized to increase evanescent field prior to the fabrication process. This is crucial in order to make sure that the surface intensity is sufficient for optical trapping. Simulation configurations are explained in detail with specific simulation flow. Discussion on parameters optimization; physical geometry, optical polarization and wavelength is included in this paper. The effect of physical, optical parameters and beam spot size on evanescent field has been thoroughly discussed. These studies will continue toward the development of a novel copper ion-exchanged waveguide as a method of particle sorting, with biological cell propulsion studies presently underway.

  7. Morphology of gold and copper ion-plated coatings

    Science.gov (United States)

    Spalvins, T.

    1978-01-01

    Copper and gold films (0.2 to 2 microns thick) were ion plated onto polished 304-stainless-steel, glass, mica surfaces. These coatings were examined by SEM for defects in their morphological growth. Three types of defects were distinguished: nodular growth, abnormal or runaway growth, and spits. The cause for each type of defect was investigated. Nodular growth is due to inherent substrate microdefects, abnormal or runaway growth is due to external surface inclusions, and spits are due to nonuniform evaporation (ejection of droplets). All these defects induce stresses and produce porosity in the coatings and thus weaken their mechanical properties. During surface rubbing, large nodules are pulled out, leaving vacancies in the coatings.

  8. Copper electrodeposition from cuprous chloride solutions containing lead, zinc or iron ions

    Institute of Scientific and Technical Information of China (English)

    M. Tchoumou; M. Roynette Ehics

    2005-01-01

    Cuprous chloride hydrochloric acid solutions were electrolysed in a two compartments cell without agitation for copper extraction. It is found that the current density affects the colour and the size of copper deposits. During electrodeposition of copper from cuprous solution in the presence of various concentrations of lead, zinc or iron ions at different current densities, it is observed that lead is codeposited with copper by increasing current density.In all experiments, the current efficiency for the copper deposition reaction fluctuates between 88.50% and 95.50%.

  9. Genes conferring copper resistance in Sinorhizobium meliloti CCNWSX0020 also promote the growth of Medicago lupulina in copper-contaminated soil.

    Science.gov (United States)

    Li, Zhefei; Ma, Zhanqiang; Hao, Xiuli; Rensing, Christopher; Wei, Gehong

    2014-03-01

    Sinorhizobium meliloti CCNWSX0020, isolated from root nodules of Medicago lupulina growing in gold mine tailings in the northwest of China, displayed both copper resistance and growth promotion of leguminous plants in copper-contaminated soil. Nevertheless, the genetic and biochemical mechanisms responsible for copper resistance in S. meliloti CCNWSX0020 remained uncharacterized. To investigate genes involved in copper resistance, an S. meliloti CCNWSX0020 Tn5 insertion library of 14,000 mutants was created. Five copper-sensitive mutants, named SXa-1, SXa-2, SXc-1, SXc-2, and SXn, were isolated, and the disrupted regions involved were identified by inverse PCR and subsequent sequencing. Both SXa-1 and SXa-2 carried a transposon insertion in lpxXL (SM0020_18047), encoding the LpxXL C-28 acyltransferase; SXc-1 and SXc-2 carried a transposon insertion in merR (SM0020_29390), encoding the regulatory activator; SXn contained a transposon insertion in omp (SM0020_18792), encoding a hypothetical outer membrane protein. The results of reverse transcriptase PCR (RT-PCR) combined with transposon gene disruptions revealed that SM0020_05862, encoding an unusual P-type ATPase, was regulated by the MerR protein. Analysis of the genome sequence showed that this P-type ATPase did not contain an N-terminal metal-binding domain or a CPC motif but rather TPCP compared with CopA from Escherichia coli. Pot experiments were carried out to determine whether growth and copper accumulation of the host plant M. lupulina were affected in the presence of the wild type or the different mutants. Soil samples were subjected to three levels of copper contamination, namely, the uncontaminated control and 47.36 and 142.08 mg/kg, and three replicates were conducted for each treatment. The results showed that the wild-type S. meliloti CCNWSX0020 enabled the host plant to grow better and accumulate copper ions. The plant dry weight and copper content of M. lupulina inoculated with the 5 copper

  10. Copper resistance in Enterococcus faecium, mediated by the tcrB gene, is selected by supplementation of pig feed with copper sulfate

    DEFF Research Database (Denmark)

    Hasman, Henrik; Kempf, I.; Chidaine, B.;

    2006-01-01

    The tcr gene cluster mediates in vitro copper resistance in Enterococcus faecium. Here we describe the selection of tcr-mediated copper resistance in E. faecium in an animal feeding experiment with young pigs fed 175 mg copper/kg feed (ppm), which is the concentration commonly used for piglets...... in European pig production. tcr-mediated copper resistance was not selected for in a control group fed low levels of copper (6 ppm). We also show coselection of macrolide- and glycopeptide-resistant E. faecium in the animal group fed the high level of copper. Finally, we identify the tcr genes...

  11. Field dependent surface resistance of niobium on copper cavities

    Directory of Open Access Journals (Sweden)

    T. Junginger

    2015-07-01

    Full Text Available The surface resistance R_{S} of superconducting cavities prepared by sputter coating a niobium film on a copper substrate increases significantly stronger with the applied rf field compared to cavities of bulk material. A possible cause is that the thermal boundary resistance between the copper substrate and the niobium film induces heating of the inner cavity wall, resulting in a higher R_{S}. Introducing helium gas in the cavity, and measuring its pressure as a function of applied field allowed to conclude that the inner surface of the cavity is heated up by less than 120 mK when R_{S} increases with E_{acc} by 100  nΩ. This is more than one order of magnitude less than what one would expect from global heating. Additionally, the effects of cooldown speed and low temperature baking have been investigated in the framework of these experiments. It is shown that for the current state of the art niobium on copper cavities there is only a detrimental effect of low temperature baking. A fast cooldown results in a lowered R_{S}.

  12. Initial copper stress strengthens the resistance of soil microorganisms to a subsequent copper stress.

    Science.gov (United States)

    Li, Jing; Zheng, Yuan-Ming; Liu, Yu-Rong; Ma, Yi-Bing; Hu, Hang-Wei; He, Ji Zheng

    2014-05-01

    To improve the prediction of essential ecosystem functioning under future environmental disturbances, it is of significance to identify responses of soil microorganisms to environmental stresses. In this study, we collected polluted soil samples from field plots with eight copper levels ranging from 0 to 3,200 mg Cu kg(-1) soil. Then, the soils with 0 and 3,200 mg Cu kg(-1) were selected to construct a microcosm experiment. Four treatments were set up including Cu0-C and Cu3200-C without further Cu addition, and Cu0-A and Cu3200-A with addition of 57.5 mg Cu kg(-1) soil. We measured substrate-induced respiration (SIR) and potential nitrification rate (PNR). Furthermore, the abundance of bacterial, archaeal 16S rRNA genes, ammonia-oxidizing bacteria and archaea amoA genes were determined through quantitative PCR. The soil microbial communities were investigated by terminal restriction fragment length polymorphism (T-RFLP). For the field samples, the SIR and PNR as well as the abundance of soil microorganisms varied significantly between eight copper levels. Soil microbial communities highly differed between the low and high copper stress. In the microcosm experiment, the PNR and SIR both recovered while the abundance of soil microorganisms varied irregularly during the 90-day incubation. The differences of microbial communities measured by pairwise Bray-Curtis dissimilarities between Cu0-A and Cu0-C on day 0 were significantly higher after subsequent stress than before. However, the differences of microbial communities between Cu3200-A and Cu3200-C on day 0 changed little between after subsequent stress and before. Therefore, initial copper stress could increase the resistance of soil microorganisms to subsequent copper stress.

  13. A new copper containing MALDI matrix that yields high abundances of [peptide + Cu]+ ions.

    Science.gov (United States)

    Wu, Zhaoxiang; Fernandez-Lima, Francisco A; Perez, Lisa M; Russell, David H

    2009-07-01

    The dinuclear copper complex (alpha-cyano-4-hydroxycinnamic acid (CHCA) copper salt (CHCA)(4)Cu(2)), synthesized by reacting CHCA with copper oxide (CuO), yields increased abundances of [M + xCu - (x-1)H](+) (x = 1-6) ions when used as a matrix for matrix-assisted laser desorption ionization (355 nm Nd:YAG laser). The yield of [M + xCu - (x-1)H](+) (x = 1 to approximately 6) ion is much greater than that obtained by mixing peptides with copper salts or directly depositing peptides onto oxidized copper surfaces. The increased ion yields for [M + xCu - (x-1)H](+) facilitate studies of biologically important copper binding peptides. For example, using this matrix we have investigated site-specific copper binding of several peptides using fragmentation chemistry of [M + Cu](+) and [M + 2Cu - H](+) ions. The fragmentation studies reveal interesting insight on Cu binding preferences for basic amino acids. Most notable is the fact that the binding of a single Cu(+) ion and two Cu(+) ions are quite different, and these differences are explained in terms of intramolecular interactions of the peptide-Cu ionic complex.

  14. Effects of Excess Copper Ions on Decidualization of Human Endometrial Stromal Cells.

    Science.gov (United States)

    Li, Ying; Kang, Zhen-Long; Qiao, Na; Hu, Lian-Mei; Ma, Yong-Jiang; Liang, Xiao-Huan; Liu, Ji-Long; Yang, Zeng-Ming

    2017-05-01

    The aim of this study was to investigate the effects of copper ions on decidualization of human endometrial stromal cells (HESCs) cultured in vitro. Firstly, non-toxic concentrations of copper D-gluconate were screened in HESCs based on cell activity. Then, the effects of non-toxic concentrations of copper ions (0~250 μM) were examined on decidualization of human endometrial stromal cells. Our data demonstrated that the mRNA expressions of insulin-like growth factor binding protein (IGFBP-1), prolactin (PRL), Mn-SOD, and FOXO1were down-regulated during decidualization following the treatments with 100 or 250 μM copper ions. Meanwhile, the amount of malonaldehyde (MDA) in the supernatant of HESCs was increased. These results showed that in vitro decidualization of HESCs was impaired by copper treatment.

  15. Radiation resistance of copper alloys at high exposure levels

    Energy Technology Data Exchange (ETDEWEB)

    Garner, F.A. (Pacific Northwest Lab., Richland, WA (USA)); Zinkle, S.J. (Oak Ridge National Lab., TN (USA))

    1990-08-01

    Copper alloys are currently being considered for high heat flux applications in fusion power devices. A review is presented of the results of two separate series of experiments on the radiation response of copper and copper alloys. One of these involved pure copper and boron-doped copper in the ORR mixed spectrum reactor. The other series included pure copper and a wide array of copper alloys irradiated in the FFTF fast reactor 16 refs., 13 figs.

  16. Evolution of a Heavy Metal Homeostasis/Resistance Island Reflects Increasing Copper Stress in Enterobacteria.

    Science.gov (United States)

    Staehlin, Benjamin M; Gibbons, John G; Rokas, Antonis; O'Halloran, Thomas V; Slot, Jason C

    2016-02-17

    Copper homeostasis in bacteria is challenged by periodic elevation of copper levels in the environment, arising from both natural sources and human inputs. Several mechanisms have evolved to efflux copper from bacterial cells, including thecus(copper sensing copper efflux system), andpco(plasmid-borne copper resistance system) systems. The genes belonging to these two systems can be physically clustered in a Copper Homeostasis and Silver Resistance Island (CHASRI) on both plasmids and chromosomes in Enterobacteria. Increasing use of copper in agricultural and industrial applications raises questions about the role of human activity in the evolution of novel copper resistance mechanisms. Here we present evidence that CHASRI emerged and diversified in response to copper deposition across aerobic and anaerobic environments. An analysis of diversification rates and a molecular clock model suggest that CHASRI experienced repeated episodes of elevated diversification that could correspond to peaks in human copper production. Phylogenetic analyses suggest that CHASRI originated in a relative ofEnterobacter cloacaeas the ultimate product of sequential assembly of several pre-existing two-gene modules. Once assembled, CHASRI dispersed via horizontal gene transfer within Enterobacteriaceae and also to certain members of Shewanellaceae, where the originalpcomodule was replaced by a divergentpcohomolog. Analyses of copper stress mitigation suggest that CHASRI confers increased resistance aerobically, anaerobically, and during shifts between aerobic and anaerobic environments, which could explain its persistence in facultative anaerobes and emergent enteric pathogens. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  17. Kinetics of copper ion absorption by cross-linked calcium polyacrylate membranes

    Science.gov (United States)

    Philipp, W. H.; May, C. E.

    1983-01-01

    The absorption of copper ions from aqueous copper acetate solutions by cross-linked calcium acrylate membranes was found to obey parabolic kinetics similar to that found for oxidation of metals that form protective oxide layers. For pure calcium polyacrylate membranes the rate constant was essentially independent of copper acetate concentration and film thickness. For a cross-linked copolymer film of polyvinyl alcohol and calcium polyacrylate, the rate constant was much greater and dependent on the concentration of copper acetate. The proposed mechanism in each case involves the formation of a copper polyacrylate phase on the surface of the membrane. The diffusion of the copper ion through this phase appears to be the rate controlling step for the copolymer film. The diffusion of the calcium ion is apparently the rate controlling step for the calcium polyacrylate. At low pH, the copper polyacrylate phase consists of the normal copper salt; at higher pH, the phase appears to be the basic copper salt.

  18. Copper diffusivity in boron-doped silicon wafer measured by dynamic secondary ion mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Songfoo [S.E.H (M) Sdn. Bhd., Lot 2, Lorong Enggang 35, Ulu Klang FTZ, 54200 Selangor (Malaysia); You, Ahheng [Faculty of Engineering and Technology, Multimedia University, Jalan Ayer Keroh Lama, Bukit Beruang, 75450 Melaka (Malaysia); Tou, Teckyong, E-mail: tytou@mmu.edu.my [Faculty of Engineering, Multimedia Univesity, Jalan Multimedia, 63100 Cyberjaya (Malaysia)

    2013-03-20

    Highlights: ► Effective copper diffusivity in boron-doped silicon wafer was measured. ► Dynamic secondary ion mass spectrometry was used. ► Interstitial copper ions were first drifted to surface region and allowed to back-diffuse. ► Boron concentration largely influenced the effect copper diffusivity. -- Abstract: The effective copper diffusivity (D{sub eff}) in boron-doped silicon wafer was measured using a Dynamic Secondary Ion Mass Spectrometry (D-SIMS) that was incorporated with an out-drift technique. By this technique, positive interstitial copper ions (Cu{sub I}{sup +}) migrated to the surface region when a continuous charge of electrons showered on the oxidized silicon wafer, which was also bombarded by primary O{sub 2}{sup +} ions. The Cu{sub I}{sup +} ions at the surface region diffused back to the bulk when the electron showering stopped. The D-SIMS recorded the real-time distribution of Cu{sub I}{sup +} ions, generating depth profiles for in-diffusion of copper for silicon-wafer samples with different boron concentrations. These were curve-fitted using the standard diffusion expressions to obtain different D{sub eff} values, and compared with other measurement techniques.

  19. Studying the Adsorption Behavior of Copper Ions in Industrial Wastewater, Using Modified Electrospun Polymeric Nano Fiber

    Directory of Open Access Journals (Sweden)

    Davood Kaviani

    2016-09-01

    Full Text Available Background & Aims of the Study:  Soil and water pollution to heavy metals is a serious threat for environment and human health. Finding an effective way for refining water from these metals is very important. The aim of this study was modifying electrospun polymeric nano fibers and studying its efficiency for copper ion omission in water solutions. Materials & Methods: In this study, nano fiber was produced by solution electrospun polystyrene in DMF/THF solvent and produced nano fiber was used for copper pre-concentration in waste water sample. In this study, an investigation of primary PH of solution, adsorption particle size, cleaning solvent volume, salt supply, contact time duration of adsorption material on copper ion adsorption supply was done, using modified nano fiber. Results: According to this study, copper adsorption process with correlation coefficient of (R2 in scope of 0.986 by Langmuir and Freundlich are describable. Findings show that, pH optimized amount for isolating copper ion on absorbent level is 7, absorbent particle size is 0.006 g/l, salt 1.3, potassium nitrate and the contact time of absorbent material on copper ion adsorption is 10 minutes. Copper ion adsorbate was cleaned, using 0.7 ml methanol. Most of obtrusive ions didn't have any inconvenience for copper ion isolation and measuring. The mean of the method was 2.7 µg/l and standard deviation was lower than %4. Conclusions: this method was done on actual samples which findings show that, this method has the ability of cooper adsorption and can use this method for measuring heavy metals like copper in different tissues. This method because of having the privilege for isolating and pre concentrating different kind of mineral and organic is used successfully in different samples.

  20. Microstructure and Corrosion Resistance of Aluminium and Copper Composite Coatings Deposited by LPCS Method

    Directory of Open Access Journals (Sweden)

    Winnicki M.

    2016-12-01

    Full Text Available The paper presents the study of microstructure and corrosion resistance of composite coatings (Al+Al2O3 and Cu+Al2O3 deposited by Low Pressure Cold Spraying method (LPCS. The atmospheric corrosion resistance was examined by subjecting the samples to cyclic salt spray and Kesternich test chambers, with NaCl and SO2 atmospheres, respectively. The selected tests allowed reflecting the actual working conditions of the coatings. The analysis showed very satisfactory results for copper coatings. After eighteen cycles, with a total time of 432 hours, the samples show little signs of corrosion. Due to their greater susceptibility to chloride ions, aluminium coatings have significant corrosion losses.

  1. Bioactive and Antibacterial Glass Powders Doped with Copper by Ion-Exchange in Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Marta Miola

    2016-05-01

    Full Text Available In this work, two bioactive glass powders (SBA2 and SBA3 were doped with Cu by means of the ion-exchange technique in aqueous solution. SBA2 glass was subjected to the ion-exchange process by using different Cu salts (copper(II nitrate, chloride, acetate, and sulphate and concentrations. Structural (X-ray diffraction-XRD, morphological (Scanning Electron Microscopy-SEM, and compositional (Energy Dispersion Spectrometry-EDS analyses evidenced the formation of crystalline phases for glasses ion-exchanged in copper(II nitrate and chloride solutions; while the ion-exchange in copper(II acetate solutions lead to the incorporation of higher Cu amount than the ion-exchange in copper(II sulphate solutions. For this reason, the antibacterial test (inhibition halo towards S. aureus was performed on SBA2 powders ion-exchanged in copper(II acetate solutions and evidenced a limited antibacterial effect. A second glass composition (SBA3 was developed to allow a greater incorporation of Cu in the glass surface; SBA3 powders were ion-exchanged in copper(II acetate solutions (0.01 M and 0.05 M. Cu-doped SBA3 powders showed an amorphous structure; morphological analysis evidenced a rougher surface for Cu-doped powders in comparison to the undoped glass. EDS and X-ray photoelectron spectroscopy (XPS confirmed the Cu introduction as Cu(II ions. Bioactivity test in simulated body fluid (SBF showed that Cu introduction did not alter the bioactive behaviour of the glass. Finally, inhibition halo test towards S. aureus evidenced a good antimicrobial effect for glass powders ion-exchanged in copper(II acetate solutions 0.05 M.

  2. Effective inhibition of the early copper ion burst release with ultra-fine grained copper and single crystal copper for intrauterine device application.

    Science.gov (United States)

    Xu, X X; Nie, F L; Wang, Y B; Zhang, J X; Zheng, W; Li, L; Zheng, Y F

    2012-02-01

    To solve the main problems of existing coarse grained copper (CG Cu) intrauterine devices (IUD)-namely burst release and a low transfer efficiency of the cupric ions during usage-ultra-fine grained copper (UFG Cu) and single crystal copper (SC Cu) have been investigated as potential substitutes. Their corrosion properties with CG Cu as a control have been studied in simulated uterine fluid (SUF) under different conditions using electrochemical measurement methods. Long-term immersion of UFG Cu, SC Cu and CG Cu samples in SUF at 37 °C have been studied for 300 days. A lower copper ion burst release and a higher efficiency release of cupric ions were observed for UFG Cu and SC Cu compared with CG Cu in the first month of immersion and 2 months later. The respective corrosion mechanisms for UFG Cu, SC Cu and CG Cu in SUF are proposed. In vitro biocompatibility tests show a better cellular response to UFG Cu and SC Cu than CG Cu. In terms of instantaneous corrosion behavior, long-term corrosion performance and in vitro biocompatibility, the three pure copper materials follow the order: UFG Cu>SC Cu>CG Cu, which indicates that UFG Cu could be the most suitable candidate material for intrauterine devices.

  3. Facile preparation of carbon wrapped copper telluride nanowires as high performance anodes for sodium and lithium ion batteries

    Science.gov (United States)

    Yu, Hong; Yang, Jun; Geng, Hongbo; Chao Li, Cheng

    2017-04-01

    Uniform carbon wrapped copper telluride nanowires were successfully prepared by using an in situ conversion reaction. The length of these nanowires is up to several micrometers and the width is around 30–40 nm. The unique one dimensional structure and the presence of conformal carbon coating of copper telluride greatly accommodate the large volumetric changes during cycling, significantly increase the electrical conductivity and reduce charge transfer resistance. The copper telluride nanowires show promising performance in a lithium ion battery with a discharge capacity of 130.2 mA h g‑1 at a high current density of 6.0 A g‑1 (26.74 C) and a stable cycling performance of 673.3 mA h g‑1 during the 60th cycle at 100 mA g‑1. When evaluated as anode material for a sodium ion battery, the copper telluride nanowires deliver a reversible capacity of 68.1 mA h g‑1 at 1.0 A g‑1 (∼4.46 C) and have a high capacity retention of 177.5 mA h g‑1 during the 500th cycle at 100 mA g‑1.

  4. Characterization of hafnium oxide resistive memory layers deposited on copper by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, B.D.; Bishop, S.M. [SUNY College of Nanoscale Science and Engineering, 255 Fuller Road, Albany, NY 12203 (United States); Leedy, K.D. [Air Force Research Laboratory, 2241 Avionics Circle, Wright Patterson Air Force Base, Dayton, OH 45433 (United States); Cady, N.C., E-mail: ncady@albany.edu [SUNY College of Nanoscale Science and Engineering, 255 Fuller Road, Albany, NY 12203 (United States)

    2014-07-01

    Hafnium oxide-based resistive memory devices have been fabricated on copper bottom electrodes. The HfO{sub x} active layers in these devices were deposited by atomic layer deposition (ALD) at 250 °C with tetrakis(dimethylamido)hafnium(IV) as the metal precursor and an O{sub 2} plasma as the reactant. Depth profiles of the HfO{sub x} by X-ray photoelectron spectroscopy and secondary ion mass spectroscopy revealed a copper concentration on the order of five atomic percent throughout the HfO{sub x} film. In addition to the Cu doped HfO{sub x}, a thin layer (20 nm) of Cu{sub x}O is present at the surface. This surface layer is believed to have formed during the ALD process, and greatly complicates the analysis of the switching mechanism. The resistive memory structures fabricated from the ALD HfO{sub x} exhibited non-polar resistive switching, independent of the top metal electrode (Ni, Pt, Al, Au). Resistive switching current voltage (I–V) curves were analyzed using Schottky emission and ionic hopping models to gain insight into the physical mechanisms underpinning the device behavior. During the forming process it was determined that, at voltages in excess of 2.5 V, an ionic hopping model is in good agreement with the I–V data. The extracted ion hopping distance ∼ 4 Å was within the range of interatomic spacing of HfO{sub 2} during the forming process consistent with ionic motion of Cu{sup 2+} ions. Lastly the on state I–V data was dominated at larger voltages by Schottky emission with an estimated barrier height of ∼ 0.5 eV and a refractive index of 2.59. The consequence of the Schottky emission analysis indicates the on state resistance to be a product of a Pt/Cu{sub 2}O/Cu filament(s)/Cu{sub 2}O/Cu structure. - Highlights: • HfO{sub 2} was grown via atomic layer deposition at 250 and 100 °C on Cu substrates. • A Cu{sub 2}O surface layer and Cu doping were observed in post-deposition of HfO{sub 2}. • Resistive memory devices were fabricated and

  5. Recovery of copper ion by flotation with potassium amylxanthate; Recuperacion de iones cobre por flotacion con amilxantato de potasio

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez-Serrano, B.; Coello-Velazquez, A. L.; Bernardo, A.; Afif, E.; Menendez-Aguado, J. M.

    2012-11-01

    In this paper a study about the column flotation process of copper ion employing potassium amylxanthate as collector reagent is carried out. The effect on the recovery of copper ion by the modification of variables such as collector/metal relation and surface velocity of gas and liquid was determined experimentally by the analysis of the statistic-mathematical model of the copper flotation process, as well as the physico-chemical phenomena that take place, showing the effect of the collector/metal relation in the process. The effect of pH as the main properties of the chemical system in the recovery and the kinetic of the flotation process is made too. The experimental results shows that the recovery of copper in the pH range of 4,5 - 12 is possible with prevalence of precipitate flotation. (Author) 43 refs.

  6. APPLICATION OF METAL RESISTANT BACTERIA BY MUTATIONAL ENHANCMENT TECHNIQUE FOR BIOREMEDIATION OF COPPER AND ZINC FROM INDUSTRIAL WASTES

    Directory of Open Access Journals (Sweden)

    M. R. Shakibaie ، A. Khosravan ، A. Frahmand ، S. Zare

    2008-10-01

    Full Text Available In this research, using mutation in the metal resistant bacteria, the bioremediation of the copper and zinc from copper factory effluents was investigated. Wastewater effluents from flocculation and rolling mill sections of a factory in the city of Kerman were collected and used for further experiments. 20 strains of Pseudomonas spp. were isolated from soil and effluents surrounding factory and identified by microbiological methods. Minimum inhibitory concentrations for copper (Cu and zinc (Zn were determined by agar dilution method. Those strains that exhibited highest minimum inhibitory concentrations values to the metals (5mM were subjected to 400-3200 mg/L concentrations of the three mutagenic agents, acriflavine, acridine orange and ethidium bromide. After determination of subinhibitory concentrations, the minimum inhibitory concentrations values for copper and zinc metal ions were again determined, which showed more than 10 fold increase in minimum inhibitory concentrations value (10 mM for Cu and 20 mM for Zn with P≤0.05. The atomic absorption spectroscopy of dried biomass obtained from resistant strains after exposure to mutagenic agents revealed that strains 13 accumulate the highest amount of intracellular copper (0.35% Cu/mg dried biomass and strain 10 showed highest accumulation of zinc (0.3% Zn/mg dried biomass respectively with P≤0.05. From above results it was concluded that the treatment of industrial waste containing heavy metals by artificially mutated bacteria may be appropriate solution for effluent disposal problems.

  7. Electrochemical removal of copper ions from dilute solutions using packed bed electrode. Part ІІ

    Directory of Open Access Journals (Sweden)

    I.A. Khattab

    2013-06-01

    Full Text Available Conversion of soluble precious copper ions into a solid form in dilute wastewater effluents for further reuse was studied by using a packed-bed cell. The cathode packing consisted of graphite particles that have an average particle size of 0.125 cm. The effects of electrolysis time and initial copper concentration were studied. The cell was found to be effective in reducing metal ion concentration to less than 0.05% of the initial concentration and maximum current efficiency reached upto 96.2% for dilute copper solution (100 mg/l. It was observed that using this cell was effective in reducing copper ion concentration from 100 mg/l to less than 4 mg/l.

  8. Size-dependent resistivity and thermopower of nanocrystalline copper

    Science.gov (United States)

    Okram, Gunadhor S.; Kaurav, Netram

    2011-07-01

    Nanocrystalline copper (NC-Cu) of average particle size (D) ranging from 29 to 55 nm was prepared using the polyol method. The compacted pellets of these nanoparticles were investigated using electrical resistivity (ρn) and thermopower (Sn) measurements in the temperature range from 5 to 300 K. The observed electrical resistivity and thermopower data for all the samples are typical of a good metal and the ρn(T) data are analyzed in the framework of the Bloch-Grüneisen theory. Our analysis indicates systematic departure from the bulk property for NC-Cu samples, decreasing effective Debye temperature, exponential decay of both the residual resistivity ratio (RRR) and the temperature coefficient of resistivity [α = (1/ρ)dρ/dT] as D decreases, yet the Boltzmann theory of electron transport still holds true (kFl ≫ 1). Further, the validity of the Nordheim-Gorter rule is also discussed. The temperature dependence of Sn is found to be quite sensitive as compared to bulk thermopower SBulk behavior, revealing the evolution of Sn and exhibiting a significant enhancement of the phonon drag peak as D decreases. The present findings overall suggest the significant influence of the grain boundaries, surface atoms, and phonon confinement.

  9. Effects of in-feed copper and tylosin supplementations on copper and antimicrobial resistance in faecal enterococci of feedlot cattle.

    Science.gov (United States)

    Amachawadi, R G; Scott, H M; Aperce, C; Vinasco, J; Drouillard, J S; Nagaraja, T G

    2015-06-01

    The objective was to investigate whether in-feed supplementation of copper, at elevated level, co-selects for macrolide resistance in faecal enterococci. The study was conducted in cattle (n = 80) with a 2 × 2 factorial design of copper (10 or 100 mg kg(-1) of feed) and tylosin (0 or 10 mg kg(-1) of feed). Thirty-seven isolates (4·6%; 37/800) of faecal enterococci were positive for the tcrB and all were Enterococcus faecium. The prevalence was higher among cattle fed diets with copper and tylosin (8·5%) compared to control (2·0%), copper (4·5%) and tylosin (3·5%) alone. All tcrB-positive isolates were positive for erm(B) and tet(M) genes. Median copper minimum inhibitory concentrations (MICs) for tcrB-positive and tcrB-negative enterococci were 20 and 4 mmol l(-1) , respectively. Feeding of elevated dietary copper and tylosin alone or in combination resulted in an increased prevalence of tcrB and erm(B)-mediated copper and tylosin-resistant faecal enterococci in feedlot cattle. In-feed supplementation of elevated dietary copper has the potential to co-select for macrolide resistance. Further studies are warranted to investigate the factors involved in maintenance and dissemination of the resistance determinants and their co-selection mechanism in relation to feed-grade antimicrobials' usage in feedlot cattle. © 2015 The Society for Applied Microbiology.

  10. Magnetic Interactions in the Copper Complex (L-Aspartato)(1,10-phenanthroline)copper(II) Hydrate. An Exchange-Coupled Extended System with Two Dissimilar Copper Ions.

    Science.gov (United States)

    Brondino, Carlos D.; Calvo, Rafael; Atria, Ana María; Spodine, Evgenia; Nascimento, Otaciro R.; Peña, Octavio

    1997-07-02

    We report EPR measurements in single-crystal samples at the microwave frequencies 9.8 and 34.3 GHz and magnetic susceptibility measurements in polycrystalline samples for the ternary complex of copper with aspartic acid and phenanthroline, (L-aspartato)(1,10-phenanthroline)copper(II) hydrate. The crystal lattice of this compound is composed of two dissimilar copper ions identified as Cu(A) and Cu(B), which are in two types of copper chains called A and B, respectively, running parallel to the b crystal axis. The copper ions in the A chains are connected by the aspartic acid molecule, and those in the B chains by a chemical path that involves a carboxylate bridge and a hydrogen bond. Both chains are held together by a complex network of hydrogen bonds and by hydrophobic interactions between aromatic amines. Magnetic susceptibility data indicate a Curie-Weiss behavior in the studied temperature range (2-300 K). The EPR spectra at 9.8 GHz display a single exchange collapsed resonance for any magnetic field orientation, in the so-called strong exchange regime. Those at 34.3 GHz are within the so-called weak exchange regime and display two resonances which belong to each type of copper ion chain. The decoupling of the spectra at 34.3 GHz using a theory based on Anderson's model for the case of two weakly exchange coupled spins S = (1)/(2) allows one to obtain the angular variation of the squares of the g-factor and the peak-to-peak line width of each resonance. This model also allows one to evaluate the exchange parameter |J(AB)/k| = 2.7(6) mK associated with the chemical path connecting dissimilar copper ions. The line width data obtained for each component of the spectra at 34.3 GHz are analyzed in terms of a model based on Kubo and Tomita's theory, to obtain the exchange parameters |J(A)/k| = 0.77(2) K and |J(B)/k| = 1.44(2) K associated with the chemical paths connecting the similar copper ions of types A and B, respectively.

  11. Mixed matrix membranes for efficient adsorption of copper ions from aqueous solutions

    NARCIS (Netherlands)

    Tetala, K.K.R.; Stamatialis, Dimitrios

    2013-01-01

    This work presents adsorption of copper (Cu2+) ions from aqueous solutions using mixed matrix membrane (MMM) and its elution afterwards. The developed flat sheet MMM, comprises of chitosan beads incorporated in Ethylene vinyl alcohol (EVAL) polymer porous matrix and exhibits static Cu2+ ion

  12. Fabrication of interfacial functionalized porous polymer monolith and its adsorption properties of copper ions.

    Science.gov (United States)

    Han, Jiaxi; Du, Zhongjie; Zou, Wei; Li, Hangquan; Zhang, Chen

    2014-07-15

    The interfacial functionalized poly (glycidyl methacrylate) (PGMA) porous monolith was fabricated and applied as a novel porous adsorbent for copper ions (Cu(2+)). PGMA porous material with highly interconnected pore network was prepared by concentrated emulsion polymerization template. Then polyacrylic acid (PAA) was grafted onto the interface of the porous monolith by the reaction between the epoxy group on PGMA and a carboxyl group on PAA. Finally, the porous monolith was interfacial functionalized by rich amount of carboxyl groups and could adsorb copper ions effectively. The chemical structure and porous morphology of the porous monolith were measured by Fourier transform infrared spectroscopy and scanning electron microscopy. Moreover, the effects of pore size distribution, pH value, co-existing ions, contacting time, and initial concentrations of copper ions on the adsorption capacity of the porous adsorbents were studied.

  13. Effects of In-Feed Copper, Chlortetracycline, and Tylosin on the Prevalence of Transferable Copper Resistance Gene, tcrB, Among Fecal Enterococci of Weaned Piglets.

    Science.gov (United States)

    Amachawadi, Raghavendra G; Scott, H Morgan; Vinasco, Javier; Tokach, Mike D; Dritz, Steve S; Nelssen, Jim L; Nagaraja, Tiruvoor G

    2015-08-01

    Heavy metals, such as copper, are increasingly supplemented in swine diets as an alternative to antibiotics to promote growth. Enterococci, a common gut commensal, acquire plasmid-borne, transferable copper resistance (tcrB) gene-mediated resistance to copper. The plasmid also carried resistance genes to tetracyclines and macrolides. The potential genetic link between copper and antibiotic resistance suggests that copper supplementation may exert a selection pressure for antimicrobial resistance. Therefore, a longitudinal study was conducted to investigate the effects of in-feed copper, chlortetracycline, and tylosin alone or in combination on the selection and co-selection of antimicrobial-resistant enterococci. The study included 240 weaned piglets assigned randomly to 6 dietary treatment groups: control, copper, chlortetracycline, tylosin, copper and chlortetracycline, and copper and tylosin. Feces were collected before (day 0), during (days 7, 14, 21), and after (days 28 and 35) initiating treatment, and enterococcal isolates were obtained from each fecal sample and tested for genotypic and phenotypic resistance to copper and antibiotics. A total of 2592 enterococcal isolates were tested for tcrB by polymerase chain reaction. The overall prevalence of tcrB-positive enterococci was 14.3% (372/2592). Among the tcrB-positive isolates, 331 were Enterococcus faecium and 41 were E. faecalis. All tcrB-positive isolates contained both erm(B) and tet(M) genes. The median minimum inhibitory concentration of copper for tcrB-negative and tcrB-positive enterococci was 6 and 18 mM, respectively. The majority of isolates (95/100) were resistant to multiple antibiotics. In conclusion, supplementing copper or antibiotics alone did not increase copper-resistant enterococci; however, supplementing antibiotics with copper increased the prevalence of the tcrB gene among fecal enterococci of piglets.

  14. Hybrid Copper-Silver Conductive Tracks for Enhanced Oxidation Resistance under Flash Light Sintering.

    Science.gov (United States)

    Yim, Changyong; Sandwell, Allen; Park, Simon S

    2016-08-31

    We developed a simple method to prepare hybrid copper-silver conductive tracks under flash light sintering. The developed metal nanoparticle-based ink is convenient because its preparation process is free of any tedious washing steps. The inks were composed of commercially available copper nanoparticles which were mixed with formic acid, silver nitrate, and diethylene glycol. The role of formic acid is to remove the native copper oxide layer on the surface of the copper nanoparticles. In this way, it facilitates the formation of a silver outer shell on the surface of the copper nanoparticles through a galvanic replacement. In the presence of formic acid, the copper nanoparticles formed copper formate, which was present in the unsintered tracks. However, under illumination by a xenon flash light, the copper formate was then converted to copper. Moreover, the resistance of the copper-only films increased by 6 orders of magnitude when oxidized at high temperatures (∼220 °C). However, addition of silver nitrate to the inks suppressed the oxidation of the hybrid copper-silver films, and the resistance changes in these inks at high temperatures were greatly reduced. In addition, the hybrid inks proved to be advantageous for use in electrical circuits as they demonstrated a stable electrical conductivity after exposure to ambient air at 180 °C.

  15. Effect of Lithium Ions on Copper Nanoparticle Size, Shape, and Distribution

    Directory of Open Access Journals (Sweden)

    Kyung-Deok Jang

    2012-01-01

    Full Text Available Copper nanoparticles were synthesized using lithium ions to increase the aqueous electrical conductivity of the solution and precisely control the size, shape, and size distribution of the particles. In this study, the conventional approach of increasing particle size by the concentration of copper ions and PGPPE in a copper chloride solution was compared to increasing the concentration of lithium chloride when the copper chloride concentration was held constant. Particle size and shape were characterized by TEM, and the size distribution of the particles at different concentrations was obtained by particle size analysis. Increasing the concentration of copper ion in the solution greatly increased the aqueous electric conductivity and the size of the particles but led to a wide size distribution ranging from 150 nm to 400 nm and rough particle morphology. The addition of lithium ions increased the size of the particles, but maintains them in a range of 250 nm. In addition the particles exhibited spherical shape as determined by TEM. The addition of lithium ions to the solution has the potential to synthesize nanoparticles with optimal characteristics for printing applications by maintaining a narrow size range and spherical shape.

  16. [Electrooptical properties of soil nitrogen-fixing bacterium Azospirillum brasilense: effect of copper ions].

    Science.gov (United States)

    Ignatov, O V; Kamnev, A A; Markina, L N; Antoniuk, L P; Kolina, M; Ignatov, V V

    2001-01-01

    The effects of copper ions on the uptake of some essential metals in the biomass and the electrooptical properties of cell suspensions of the nitrogen-fixing soil bacterium Azospirillum brasilense sp. 245 were studied. Copper cations were shown to be effectively taken up by the cell biomass from the culture medium. The addition of copper ions increased the rate of uptake of some other metals present in the culture medium. This was accompanied by changes in the electrooptical characteristics of cell suspension as measured within the orienting electric field frequency range of 10 to 10,000 kHz. The effects observed during short-term incubation of A. brasilense in the presence of copper cations were less significant than during long-term incubation. These results can be used for rapid screening of microbial cultures for enhanced efficiency of sorption and uptake of metals.

  17. Determination of copper(I) and copper(II) ions after complexation with bicinchoninic acid by CE.

    Science.gov (United States)

    Basheer, Chanbasha; Lee, Hian Kee

    2007-10-01

    A facile, sensitive, and selective method was developed for the simultaneous separation and determination of copper(I) [Cu(+)] and copper(II) [Cu(2+)] ions using CE with direct UV detection. The copper ions were complexed with a 1.5 mM bicinchoninic acid disodium salt solution at pH 8.7 prior to analysis. Acetate buffer (2 mM) was used as the CE running buffer. Parameters affecting CE separation such as sample pH, applied voltage, concentration of complexing agent, nature of the buffer solution, and interferences by other metal ions, were evaluated. The LODs for Cu(+) and Cu(2+) were 3.0 and 2.5 microg/mL (S/N = 3), respectively. The developed method allows the simultaneous determination of Cu(+) and Cu(2+) in less than 5 min with RSDs of between 5.3 and 9.5% for migration time and between 3.4 and 9.7% for peak areas, respectively. At optimum conditions, the percentage recoveries of Cu(+) and Cu(2+) were found to be 99.4 and 99.5%.

  18. Evaluation of copper ion of antibacterial effect on Pseudomonas aeruginosa, Salmonella typhimurium and Helicobacter pylori and optical, mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young-Hwan [School of Materials Science and Engineering, University of Yonsei, Seoul (Korea, Republic of); Choi, Yu-ri; Kim, Kwang-Mahn [Department and Research Institute of Dental Biomaterials and Bioengineering, College of Dentistry, University of Yonsei, Seoul (Korea, Republic of); Choi, Se-Young, E-mail: sychoi@yonsei.ac.kr [School of Materials Science and Engineering, University of Yonsei, Seoul (Korea, Republic of)

    2012-02-01

    Antibacterial effect on Pseudomonas aeruginosa, Salmonella typhimurium and Helicobacter pylori of copper ion was researched. Also, additional effects of copper ion coating on optical and mechanical properties were researched as well. Copper ion was coated on glass substrate as a thin film to prevent bacteria from growing. Cupric nitrate was used as precursors for copper ion. The copper ion contained sol was deposited by spin coating process on glass substrate. Then, the deposited substrates were heat treated at the temperature range between 200 Degree-Sign C and 250 Degree-Sign C. The thickness of deposited copper layer on the surface was 63 nm. The antibacterial effect of copper ion coated glass on P. aeruginosa, S. typhimurium and H. pylori demonstrated excellent effect compared with parent glass. Copper ion contained layer on glass showed a similar value of transmittance compared with value of parent glass. The 3-point bending strength and Vickers hardness were 209.2 MPa, 540.9 kg/mm{sup 2} which were about 1.5% and 1.3% higher than the value of parent glass. From these findings, it is clear that copper ion coating on glass substrate showed outstanding effect not only in antibacterial activity but also in optical and mechanical properties as well.

  19. Evaluation of copper ion of antibacterial effect on Pseudomonas aeruginosa, Salmonella typhimurium and Helicobacter pylori and optical, mechanical properties

    Science.gov (United States)

    Kim, Young-Hwan; Choi, Yu-ri; Kim, Kwang-Mahn; Choi, Se-Young

    2012-02-01

    Antibacterial effect on Pseudomonas aeruginosa, Salmonella typhimurium and Helicobacter pylori of copper ion was researched. Also, additional effects of copper ion coating on optical and mechanical properties were researched as well. Copper ion was coated on glass substrate as a thin film to prevent bacteria from growing. Cupric nitrate was used as precursors for copper ion. The copper ion contained sol was deposited by spin coating process on glass substrate. Then, the deposited substrates were heat treated at the temperature range between 200 °C and 250 °C. The thickness of deposited copper layer on the surface was 63 nm. The antibacterial effect of copper ion coated glass on P. aeruginosa, S. typhimurium and H. pylori demonstrated excellent effect compared with parent glass. Copper ion contained layer on glass showed a similar value of transmittance compared with value of parent glass. The 3-point bending strength and Vickers hardness were 209.2 MPa, 540.9 kg/mm2 which were about 1.5% and 1.3% higher than the value of parent glass. From these findings, it is clear that copper ion coating on glass substrate showed outstanding effect not only in antibacterial activity but also in optical and mechanical properties as well.

  20. Multipath colourimetric assay for copper(II) ions utilizing MarR functionalized gold nanoparticles

    Science.gov (United States)

    Wang, Yulong; Wang, Limin; Su, Zhenhe; Xue, Juanjuan; Dong, Jinbo; Zhang, Cunzheng; Hua, Xiude; Wang, Minghua; Liu, Fengquan

    2017-02-01

    We use the multiple antibiotic resistance regulator (MarR), as a highly selective biorecognition elements in a multipath colourimetric sensing strategy for the fast detection of Cu2+ in water samples. The colourimetric assay is based on the aggregation of MarR-coated gold nanoparticles in the presence of Cu2+ ions, which induces a red-to-purple colour change of the solution. The colour variation in the gold nanoparticle aggregation process can be used for qualitative and quantitative detection of Cu2+ by the naked eye, and with UV–vis and smartphone-based approaches. The three analysis techniques used in the multipath colourimetric assay complement each other and provide greater flexibility for differing requirements and conditions, making the assay highly applicable for Cu2+ detection. Under optimal conditions, the Cu2+ concentration was quantified in less than 5 min with limits of detection for the naked eye, UV–vis and smartphone-based approaches of 1 μM, 405 nM and 61 nM, respectively. Moreover, the sensing system exhibited excellent selectivity and practical application for Cu2+ detection in real water samples. Thus, our strategy has great potential for application in on-site monitoring of Cu2+, and the unique response of MarR towards copper ions may provide a new approach to Cu2+ sensing.

  1. Multipath colourimetric assay for copper(II) ions utilizing MarR functionalized gold nanoparticles

    Science.gov (United States)

    Wang, Yulong; Wang, Limin; Su, Zhenhe; Xue, Juanjuan; Dong, Jinbo; Zhang, Cunzheng; Hua, Xiude; Wang, Minghua; Liu, Fengquan

    2017-01-01

    We use the multiple antibiotic resistance regulator (MarR), as a highly selective biorecognition elements in a multipath colourimetric sensing strategy for the fast detection of Cu2+ in water samples. The colourimetric assay is based on the aggregation of MarR-coated gold nanoparticles in the presence of Cu2+ ions, which induces a red-to-purple colour change of the solution. The colour variation in the gold nanoparticle aggregation process can be used for qualitative and quantitative detection of Cu2+ by the naked eye, and with UV–vis and smartphone-based approaches. The three analysis techniques used in the multipath colourimetric assay complement each other and provide greater flexibility for differing requirements and conditions, making the assay highly applicable for Cu2+ detection. Under optimal conditions, the Cu2+ concentration was quantified in less than 5 min with limits of detection for the naked eye, UV–vis and smartphone-based approaches of 1 μM, 405 nM and 61 nM, respectively. Moreover, the sensing system exhibited excellent selectivity and practical application for Cu2+ detection in real water samples. Thus, our strategy has great potential for application in on-site monitoring of Cu2+, and the unique response of MarR towards copper ions may provide a new approach to Cu2+ sensing. PMID:28155905

  2. Electrical nanocharacterization of copper tetracyanoquinodimethane layers dedicated to resistive random access memories

    Science.gov (United States)

    Deleruyelle, Damien; Muller, Christophe; Amouroux, Julien; Müller, Robert

    2010-06-01

    The local electrical properties of copper tetracyanoquinodimethane (CuTCNQ)/HfO2/Pt stacks were investigated thanks to conductive-atomic force microscopy (AFM) measurements. Local I-V and I-t spectroscopy evidenced repeatable and reversible bipolar electrical switching (SET and RESET operations) at the nanometer scale beneath the AFM tip. Experimental results suggest that resistive switching is due to the creation/dissolution of conductive filaments bridging the CuTCNQ surface to the AFM tip. A physical model based on the migration of Cu+ ions within a nanogap and the growth of a conductive filament shows an excellent agreement with the experimental results during SET operation achieved at nanoscale.

  3. SOURCES OF COPPER IONS AND SELECTED METHODS OF THEIR REMOVAL FROM WASTEWATER FROM THE PRINTED CIRCUITS BOARD PRODUCTION

    Directory of Open Access Journals (Sweden)

    Maciej Thomas

    2014-10-01

    Full Text Available This paper presents the issues related to the presence and removal of copper compounds from industrial effluents with including wastewater from plants involved in the production of printed circuit boards. Characterized the toxicological properties of selected copper compounds, described the applicable technological processes, sources of copper ions in the effluents and selected methods for their removal.

  4. Combined effects of water temperature and copper ion concentration on catalase activity in Crassostrea ariakensis

    Science.gov (United States)

    Wang, Hui; Yang, Hongshuai; Liu, Jiahui; Li, Yanhong; Liu, Zhigang

    2015-07-01

    A central composite experimental design and response surface method were used to investigate the combined effects of water temperature (18-34°C) and copper ion concentration (0.1-1.5 mg/L) on the catalase (CAT) activity in the digestive gland of Crassostrea ariakensis. The results showed that the linear effects of temperature were significant ( P0.05), and the quadratic effects of copper ion concentration were significant ( P0.05), and the effect of temperature was greater than that of copper ion concentration. A model equation of CAT enzyme activity in the digestive gland of C. ariakensis toward the two factors of interest was established, with R 2, Adj. R 2 and Pred. R 2 values as high as 0.943 7, 0.887 3 and 0.838 5, respectively. These findings suggested that the goodness of fit to experimental data and predictive capability of the model were satisfactory, and could be practically applied for prediction under the conditions of the study. Overall, the results suggest that the simultaneous variation of temperature and copper ion concentration alters the activity of the antioxidant enzyme CAT by modulating active oxygen species metabolism, which may be utilized as a biomarker to detect the effects of copper pollution.

  5. Simultaneous removal of copper and lead ions from a binary solution by sono-sorption process

    Energy Technology Data Exchange (ETDEWEB)

    Entezari, M.H. [Department of Chemistry, Ferdowsi University of Mashhad, 91775 Mashhad (Iran, Islamic Republic of)], E-mail: moh_entezari@yahoo.com; Soltani, T. [Department of Chemistry, Ferdowsi University of Mashhad, 91775 Mashhad (Iran, Islamic Republic of)

    2008-12-15

    The aim of this work is to compare the simultaneous sorption of copper and lead ions from a binary aqueous solution in the presence and in the absence of ultrasound. The experiments under sonication were carried out by 20-kHz apparatus. Results indicated that the removal of copper and lead ions from a binary aqueous solution was greater in the presence of ultrasound than in control method. The removal of these ions was examined by varying experimental conditions such as the amount of sorbent, contact time, and temperature. In addition, the competitive sorption of ions was considered with different concentrations of each ion under the constant total concentration. The Langmuir isotherm model fits adequately the experimental data. In point of kinetics, the second-order kinetic model describes the sorption process for both ions. It was found that more than 90% of the lead and 60% of the copper ions was removed in less than 2 min from the solution under sonication. The thermodynamic parameters such as {delta}G{sup o}, {delta}H{sup o}, and {delta}S{sup o} were determined for the sorption of Cu{sup 2+} and Pb{sup 2+} from the temperature dependence of the sorption process.

  6. Copper Resistance Gene Homologs in Pathogenic and Saprophytic Bacterial Species from Tomato

    OpenAIRE

    Cooksey, Donald A.; Azad, Hamid R.; Cha, Jae-Soon; Lim, Chun-Keun

    1990-01-01

    Copper-resistant strains of Xanthomonas campestris pv. vesicatoria, Pseudomonas cichorii, Pseudomonas putida, Pseudomonas fluorescens, and a yellow Pseudomonas sp. were isolated from tomato plants or seeds. In Southern hybridizations, DNA from each strain showed homology with the copper resistance (cop) operon previously cloned from Pseudomonas syringae pv. tomato PT23. Homology was associated with plasmid and chromosomal DNA in X. compestris pv. vesicatoria, P. putida, and the yellow Pseudom...

  7. Biosorption effects of copper ions on Candida utilis under negative pressure cavitation

    Institute of Scientific and Technical Information of China (English)

    ZU Yuan-gang; ZHAO Xiu-hua; HU Mao-sheng; REN Yuan; XIAO Peng; ZHU Lei; CAO Yu-jie; ZHANG Yao

    2006-01-01

    Under the optimal condition of copper ions adsorption on yeast, we found some different effects among static adsorption,shaking adsorption and negative pressure cavitation adsorption, and the methods of yeast with different pretreatments also affect adsorption of copper ions. At the same time, the change of intercellular pH before and after adsorption of copper with BCECF was studied. The copper distribution was located by using PhenGreen (dipotassium salt and diacetate), and the surface of yeast was observed by an atomic force microscope. The results showed that negative pressure cavitation can improve bioadsorption capacity of copper ions on yeast. However, the yeasts' pretreatment has a higher effect on bioadsorption. It indicates that heavy metal bioadsorption on yeast has much relation with its cellular molecule basis. With the adsorping, the intercellular pH of yeast increased gradually and changed from acidity to alkalescence. These results may suggest that negative pressure cavitation can compel heavy metals to transfer from the cell surface into inside cell and make the surface of yeast coarse.

  8. Development of a four-zone carousel process packed with metal ion-imprinted polymer for continuous separation of copper ions from manganese ions, cobalt ions, and the constituent metal ions of the buffer solution used as eluent.

    Science.gov (United States)

    Jo, Se-Hee; Park, Chanhun; Yi, Sung Chul; Kim, Dukjoon; Mun, Sungyong

    2011-08-19

    A three-zone carousel process, in which Cu(II)-imprinted polymer (Cu-MIP) and a buffer solution were employed as adsorbent and eluent respectively, has been developed previously for continuous separation of Cu²⁺ (product) from Mn²⁺ and Co²⁺ (impurities). Although this process was reported to be successful in the aforementioned separation task, the way of using a buffer solution as eluent made it inevitable that the product stream included the buffer-related metal ions (i.e., the constituent metal ions of the buffer solution) as well as copper ions. For a more perfect recovery of copper ions, it would be necessary to improve the previous carousel process such that it can remove the buffer-related metal ions from copper ions while maintaining the previous function of separating copper ions from the other 2 impure heavy-metal ions. This improvement was made in this study by proposing a four-zone carousel process based on the following strategy: (1) the addition of one more zone for performing the two-step re-equilibration tasks and (2) the use of water as the eluent of the washing step in the separation zone. The operating conditions of such a proposed process were determined on the basis of the data from a series of single-column experiments. Under the determined operating conditions, 3 runs of carousel experiments were carried out. The results of these experiments revealed that the feed-loading time was a key parameter affecting the performance of the proposed process. Consequently, the continuous separation of copper ions from both the impure heavy-metal ions and the buffer-related metal ions could be achieved with a purity of 91.9% and a yield of 92.8% by using the proposed carousel process based on a properly chosen feed-loading time.

  9. Copper removal using a heavy-metal resistant microbial consortium in a fixed-bed reactor.

    Science.gov (United States)

    Carpio, Isis E Mejias; Machado-Santelli, Glaucia; Sakata, Solange Kazumi; Ferreira Filho, Sidney Seckler; Rodrigues, Debora Frigi

    2014-10-01

    A heavy-metal resistant bacterial consortium was obtained from a contaminated river in São Paulo, Brazil and utilized for the design of a fixed-bed column for the removal of copper. Prior to the design of the fixed-bed bioreactor, the copper removal capacity by the live consortium and the effects of copper in the consortium biofilm formation were investigated. The Langmuir model indicated that the sorption capacity of the consortium for copper was 450.0 mg/g dry cells. The biosorption of copper into the microbial biomass was attributed to carboxyl and hydroxyl groups present in the microbial biomass. The effect of copper in planktonic cells to form biofilm under copper rich conditions was investigated with confocal microscopy. The results revealed that biofilm formed after 72 h exposure to copper presented a reduced thickness by 57% when compared to the control; however 84% of the total cells were still alive. The fixed-bed bioreactor was set up by growing the consortium biofilm on granular activated carbon (GAC) and analyzed for copper removal. The biofilm-GAC (BGAC) column retained 45% of the copper mass present in the influent, as opposed to 17% in the control column that contained GAC only. These findings suggest that native microbial communities in sites contaminated with heavy metals can be immobilized in fixed-bed bioreactors and used to treat metal contaminated water.

  10. Metal ions to control the morphology of semiconductor nanoparticles: copper selenide nanocubes.

    Science.gov (United States)

    Li, Wenhua; Zamani, Reza; Ibáñez, Maria; Cadavid, Doris; Shavel, Alexey; Morante, Joan Ramon; Arbiol, Jordi; Cabot, Andreu

    2013-03-27

    Morphology is a key parameter in the design of novel nanocrystals and nanomaterials with controlled functional properties. Here, we demonstrate the potential of foreign metal ions to tune the morphology of colloidal semiconductor nanoparticles. We illustrate the underlying mechanism by preparing copper selenide nanocubes in the presence of Al ions. We further characterize the plasmonic properties of the obtained nanocrystals and demonstrate their potential as a platform to produce cubic nanoparticles with different composition by cation exchange.

  11. Copper ions stimulate the proliferation of hepatic stellate cells via oxygen stress in vitro.

    Science.gov (United States)

    Xu, San-qing; Zhu, Hui-yun; Lin, Jian-guo; Su, Tang-feng; Liu, Yan; Luo, Xiao-ping

    2013-02-01

    This study examined the effect of copper ions on the proliferation of hepatic stellate cells (HSCs) and the role of oxidative stress in this process in order to gain insight into the mechanism of hepatic fibrosis in Wilson's disease. LX-2 cells, a cell line of human HSCs, were cultured in vitro and treated with different agents including copper sulfate, N-acetyl cysteine (NAC) and buthionine sulfoximine (BSO) for different time. The proliferation of LX-2 cells was measured by non-radioactive cell proliferation assay. Real-time PCR and Western blotting were used to detect the mRNA and protein expression of platelet-derived growth factor receptor β subunit (PDGFβR), ELISA to determine the level of glutathione (GSH) and oxidized glutathione (GSSG), dichlorofluorescein assay to measure the level of reactive oxygen species (ROS), and lipid hydroperoxide assay to quantify the level of lipid peroxide (LPO). The results showed that copper sulfate over a certain concentration range could promote the proliferation of LX-2 cells in a time- and dose-dependent manner. The effect was most manifest when LX-2 cells were treated with copper sulfate at a concentration of 100 μmol/L for 24 h. Additionally, copper sulfate could dose-dependently increase the levels of ROS and LPO, and decrease the ratio of GSH/GSSG in LX-2 cells. The copper-induced increase in mRNA and protein expression of PDGFβR was significantly inhibited in LX-2 cells pre-treated with NAC, a precursor of GSH, and this phenomenon could be reversed by the intervention of BSO, an inhibitor of NAC. It was concluded that copper ions may directly stimulate the proliferation of HSCs via oxidative stress. Anti-oxidative stress therapies may help suppress the copper-induced activation and proliferation of HSCs.

  12. Biodynamics of copper oxide nanoparticles and copper ions in an oligochaete, Part I

    DEFF Research Database (Denmark)

    Ramskov, Tina; Thit, Amalie; Croteau, Marie-Noelle

    2015-01-01

    Copper oxide (CuO) nanoparticles (NPs) are widely used, and likely released into the aquatic environment. Both aqueous (i.e., dissolved Cu) and particulate Cu can be taken up by organisms. However, how exposure routes influence the bioavailability and subsequent toxicity of Cu remains largely...

  13. Copper ions removal from water using functionalized carbon nanotubes–mullite composite as adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Tofighy, Maryam Ahmadzadeh; Mohammadi, Toraj, E-mail: torajmohammadi@iust.ac.ir

    2015-08-15

    Highlights: • CNTs–mullite composite was prepared via chemical vapor deposition (CVD) method. • The prepared composite was modified with concentrated nitric acid and chitosan. • The modified CNTs–mullite composites were used as novel adsorbents. • Copper ion removal from water by the prepared adsorbents was performed. • Langmuir and Freundlich isotherms and two kinetic models were applied to fit the experimental data. - Abstract: Carbon nanotubes–mullite composite was synthesized by direct growth of carbon nanotubes on mullite particles via chemical vapor deposition method using cyclohexanol and ferrocene as carbon precursor and catalyst, respectively. The carbon nanotubes–mullite composite was oxidized with concentrated nitric acid and functionalized with chitosan and then used as a novel adsorbent for copper ions removal from water. The results demonstrated that modification with concentrated nitric acid and chitosan improves copper ions adsorption capacity of the prepared composite, significantly. Langmuir and Freundlich isotherms and two kinetic models were applied to fit the experimental data. The carbon nanotubes growth on mullite particles to form the carbon nanotubes–mullite composite with further modification is an inherently safe approach for many promising environmental applications to avoid some concerns regarding environment, health and safety. It was found that the modified carbon nanotubes–mullite composite can be considered as an excellent adsorbent for copper ions removal from water.

  14. Thin copper oxide films prepared by ion beam sputtering with subsequent thermal oxidation: Application in chemiresistors

    Science.gov (United States)

    Horak, P.; Bejsovec, V.; Vacik, J.; Lavrentiev, V.; Vrnata, M.; Kormunda, M.; Danis, S.

    2016-12-01

    Copper oxide films were prepared by thermal oxidation of thin Cu films deposited on substrates by ion beam sputtering. The subsequent oxidation was achieved in the temperature range of 200 °C-600 °C with time of treatment from 1 to 7 h (with a 1-h step) in a furnace open to air. At temperatures 250 °C-600 °C, the dominant phase formed was CuO, while at 200 °C mainly the Cu2O phase was identified. However, the oxidation at 200 °C led to a more complicated composition - in the depth Cu2O phase was observed, though in the near-surface layer the CuO dominant phase was found with a significant presence of Cu(OH)2. A limited amount of Cu2O was also found in samples annealed at 600 °C. The sheet resistance RS of the as-deposited Cu sample was 2.22 Ω/□, after gradual annealing RS was measured in the range 2.64 MΩ/□-2.45 GΩ/□. The highest RS values were obtained after annealing at 300 °C and 350 °C, respectively. Oxygen depth distribution was studied using the 16O(α,α) nuclear reaction with the resonance at energy 3032 keV. It was confirmed that the higher oxidation degree of copper is located in the near-surface region. Preliminary tests of the copper oxide films as an active layer of a chemiresistor were also performed. Hydrogen and methanol vapours, with a concentration of 1000 ppm, were detected by the sensor at an operating temperature of 300 °C and 350 °C, respectively. The response of the sensors, pointed at the p-type conductivity, was improved by the addition of thin Pd or Au catalytic films to the oxidic film surface. Pd-covered films showed an increased response to hydrogen at 300 °C, while Au-covered films were more sensitive to methanol vapours at 350 °C.

  15. A copper-catalyzed bioleaching process for enhancement of cobalt dissolution from spent lithium-ion batteries.

    Science.gov (United States)

    Zeng, Guisheng; Deng, Xiaorong; Luo, Shenglian; Luo, Xubiao; Zou, Jianping

    2012-01-15

    A copper-catalyzed bioleaching process was developed to recycle cobalt from spent lithium-ion batteries (mainly LiCoO(2)) in this paper. The influence of copper ions on bioleaching of LiCoO(2) by Acidithiobacillus ferrooxidans (A.f) was investigated. It was shown that almost all cobalt (99.9%) went into solution after being bioleached for 6 days in the presence of 0.75 g/L copper ions, while only 43.1% of cobalt dissolution was obtained after 10 days without copper ions. EDX, XRD and SEM analyses additionally confirmed that the cobalt dissolution from spent lithium-ion batteries could be improved in the presence of copper ions. The catalytic mechanism was investigated to explain the enhancement of cobalt dissolution by copper ions, in which LiCoO(2) underwent a cationic interchange reaction with copper ions to form CuCo(2)O(4) on the surface of the sample, which could be easily dissolved by Fe(3+).

  16. Wear and corrosion resistance of laser remelted and plasma sprayed Ni and Cr coatings on copper

    Institute of Scientific and Technical Information of China (English)

    梁工英; 黄俊达; 安耿

    2004-01-01

    Nickel and chromium coatings were produced on the copper sheet using plasma spraying and laser remelting. The sliding wear test was achieved on a block-on-ring tester and the corrosion test was carried out in an acidic atmosphere. The corrosive behaviors of both coatings and original copper samples were investigated by using an impedance comparison method. The experimental results show that the nickel and chromium coatings display better wear resistance and corrosion resistance relative to the original pure copper sample. The wear resistance of the coatings is 8 - 12 times as large as original samples, and the wear resistance of laser remelted samples is better than that of plasma sprayed ones. The corrosion resistance of laser remelted nickel and chromium samples is better than that of plasma sprayed samples respectively. The corrosion rate of chromium coatings is less than that of nickel coatings, and the laser remelted Cr coating exhibits the least corrosion rate.

  17. Level of Copper Ion in Cervical Mucus of Various Duration after Inserting VCu200 IUD

    Institute of Scientific and Technical Information of China (English)

    刘庆喜; 黄祝姈; 潘琢如

    1996-01-01

    The purpose of the study was to test the effective period of VCu200 IUD. The concentration of copper ion was measured with non-flame atomic absorption s pectrophotometer HITACHI- 180. The average concentration of copper ion(x±sx) was 2.66±0.58 μg/g cervical mucus wet weight (μg/g · M·W·W) in the first year, then gradually decreasing to 0.91±0. 16 μg/g·M·W·W in the fifteenth-year group of VCu200 IUD. There was an average of 0.35±0.08~0. 56±0. 14 μg/g·M·W·W in the control group. It showed that the concentration of copper ion was decreasing with prolongation of use of VCu200 IUD and there was statistically significant difference between VCu200 IUD group, on the one hand, and the stainless steel ring group and the control group (P<0.05~0. 01) on the other hand. No difference was found between the stainless steel ring group and the control group (P>0. 05). It was reported in the literature that the concentration of copper ion in 1.0 μg/ml had the action of anti fertility, and it was found that the concentration of copper ion was higher than 1.0 μg/ml in the tenth year after insertion of VCu200 IUD. It suggested that effective period of VCu200 IUD was at least ten years.

  18. A genomic island provides Acidithiobacillus ferrooxidans ATCC 53993 additional copper resistance: a possible competitive advantage.

    Science.gov (United States)

    Orellana, Luis H; Jerez, Carlos A

    2011-11-01

    There is great interest in understanding how extremophilic biomining bacteria adapt to exceptionally high copper concentrations in their environment. Acidithiobacillus ferrooxidans ATCC 53993 genome possesses the same copper resistance determinants as strain ATCC 23270. However, the former strain contains in its genome a 160-kb genomic island (GI), which is absent in ATCC 23270. This GI contains, amongst other genes, several genes coding for an additional putative copper ATPase and a Cus system. A. ferrooxidans ATCC 53993 showed a much higher resistance to CuSO(4) (>100 mM) than that of strain ATCC 23270 (<25 mM). When a similar number of bacteria from each strain were mixed and allowed to grow in the absence of copper, their respective final numbers remained approximately equal. However, in the presence of copper, there was a clear overgrowth of strain ATCC 53993 compared to ATCC 23270. This behavior is most likely explained by the presence of the additional copper-resistance genes in the GI of strain ATCC 53993. As determined by qRT-PCR, it was demonstrated that these genes are upregulated when A. ferrooxidans ATCC 53993 is grown in the presence of copper and were shown to be functional when expressed in copper-sensitive Escherichia coli mutants. Thus, the reason for resistance to copper of two strains of the same acidophilic microorganism could be determined by slight differences in their genomes, which may not only lead to changes in their capacities to adapt to their environment, but may also help to select the more fit microorganisms for industrial biomining operations. © Springer-Verlag 2011

  19. New Class of Antimicrobial Agents: SBA-15 Silica Containing Anchored Copper Ions

    Directory of Open Access Journals (Sweden)

    Lukasz Laskowski

    2017-01-01

    Full Text Available The paper is about a new class of antimicrobial functional nanomaterials. Proposed compounds are based on SBA-15 porous silica matrices and contain anchored copper ions. Thanks to the immobilization of functional groups the compounds are safer for environment than commonly used disinfectant agents. We prepared and examined silica based materials containing two concentrations of copper-containing groups: 10 and 5%. For the reference we prepared samples containing free-standing CuO molecules in the structure and checked their antimicrobial properties. Antibacterial effect of considered SBA-15-Cu material was tested on Escherichia coli bacteria. Antimicrobial tests were applied for the pure form of the material and as modifying agents for plastics. The obtained results showed that the sample with lower concentration of active copper-containing groups has stronger antimicrobial properties than the one with higher concentration of copper. Interestingly, silica containing free-standing CuO molecules has no antimicrobial properties. Considering the obtained results, we can conclude that the most probable antimicrobial mechanism in this case is an oxidation stress. When a plastic modifier is applied the material is enriched with bacterial inhibitory properties. It seems that SBA-15 silica containing low concentration of anchored copper ions is promising in terms of its antibacterial property and biomaterial potential for commercial use.

  20. Relationship between copper, glycopeptide, and macrolide resistance among Enterococcus faecium strains isolated from pigs in Denmark between 1997 and 2003

    DEFF Research Database (Denmark)

    Hasman, Henrik; Aarestrup, Frank Møller

    2005-01-01

    A significant relationship between copper resistance (tcrB), glycopeptide resistance (Tn1546), and macrolide resistance [erm(B)] in Enterococcus faecium isolated from pigs was found. The tcrB gene was located closely upstream of the Tn1546 element. However, the continued use of copper sulfate has...

  1. Effect of copper (II) ion against elongation behavior of amyloid {beta} fibrils on liposome membranes

    Energy Technology Data Exchange (ETDEWEB)

    Shimanouchi, T.; Onishi, R.; Kitaura, N.; Umakoshi, H.; Kuboi, R. [Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka (Japan)

    2012-01-15

    The fibril growth behavior of amyloid {beta} protein (A{beta}) on cell membranes is relating to the progression of Alzheimer's disease. This growth behavior of A{beta} fibrils is sensitively affected by the metal ions, neurotransmitters, or bioreactive substrate. The inhibitory effect of those materials was quantitatively estimated from the viewpoints of ''crystal growth''. In a bulk aqueous solution, copper (II) ion showed the strong inhibitory effect on the growth of A{beta} fibrils. Meanwhile, the addition of a closed-phospholipid bilayer membrane (liposome) could reduce the above inhibitory effect of copper (II) ion. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Cancer Therapy by Catechins Involves Redox Cycling of Copper Ions and Generation of Reactive Oxygen Species

    Directory of Open Access Journals (Sweden)

    Mohd Farhan

    2016-02-01

    Full Text Available Catechins, the dietary phytochemicals present in green tea and other beverages, are considered to be potent inducers of apoptosis and cytotoxicity to cancer cells. While it is believed that the antioxidant properties of catechins and related dietary agents may contribute to lowering the risk of cancer induction by impeding oxidative injury to DNA, these properties cannot account for apoptosis induction and chemotherapeutic observations. Catechin (C, epicatechin (EC, epigallocatechin (EGC and epigallocatechin-3-gallate (EGCG are the four major constituents of green tea. In this article, using human peripheral lymphocytes and comet assay, we show that C, EC, EGC and EGCG cause cellular DNA breakage and can alternatively switch to a prooxidant action in the presence of transition metals such as copper. The cellular DNA breakage was found to be significantly enhanced in the presence of copper ions. Catechins were found to be effective in providing protection against oxidative stress induced by tertbutylhydroperoxide, as measured by oxidative DNA breakage in lymphocytes. The prooxidant action of catechins involved production of hydroxyl radicals through redox recycling of copper ions. We also determined that catechins, particularly EGCG, inhibit proliferation of breast cancer cell line MDA-MB-231 leading to a prooxidant cell death. Since it is well established that tissue, cellular and serum copper levels are considerably elevated in various malignancies, cancer cells would be more subject to redox cycling between copper ions and catechins to generate reactive oxygen species (ROS responsible for DNA breakage. Such a copper dependent prooxidant cytotoxic mechanism better explains the anticancer activity and preferential cytotoxicity of dietary phytochemicals against cancer cells.

  3. Effect of Some Heterocyclic Derivatives on the Removal of Copper Ions from Wastewater by Cementation

    Institute of Scientific and Technical Information of China (English)

    A.A. Taha; M.G.Marei; D.E.Abd El-khalek

    2004-01-01

    Removal of copper ions from copper sulphate solutions on a rotating zinc rod in absence and in presence of 3(2H)-furanones and 4H-pyran-4-one derivatives was investigated experimentally. Variables studied were initial copper ions concentration,rotational speed of the zinc rod, temperature and concentration of organic additives. It was found that cementation reaction is first order in presence and in absence of additives. Increasing concentration of initial copper ions, rotational speed of the zinc rod and temperature were found to increase the rate of cementation. In presence of organic additives an enhancement of the rate was observed, except in presence of methoxyfuranone the rate was found to decrease by an amount ranging from 11.74% to 33.79%. Rate acceleration or inhibition is associated mainly with changes in the structure of the additives as well as its concentration. The apparent activation energy for the cementation process in presence of different additives was estimated and was found to be ranged between 11.8 k J/mol and 25.95 k J/mol. These values suggest that the copper removal process in presence of these additives is controlled by diffusion. A scanning electron microscopy study of copper deposits obtained in presence of tolylfuranone, phenylpyrone and methoxyfuranone correlate with their behaviour during the kinetic study. Different reaction conditions and the physical properties of solutions were studied to obtain dimensionless correlation among all these parameters. It was found that on applying cementation reaction on a sample from industrial wastewater in presence of phenylpyrone about 91.9% of Cu2+ are removed.

  4. Cancer Therapy by Catechins Involves Redox Cycling of Copper Ions and Generation of Reactive Oxygen species.

    Science.gov (United States)

    Farhan, Mohd; Khan, Husain Yar; Oves, Mohammad; Al-Harrasi, Ahmed; Rehmani, Nida; Arif, Hussain; Hadi, Sheikh Mumtaz; Ahmad, Aamir

    2016-02-04

    Catechins, the dietary phytochemicals present in green tea and other beverages, are considered to be potent inducers of apoptosis and cytotoxicity to cancer cells. While it is believed that the antioxidant properties of catechins and related dietary agents may contribute to lowering the risk of cancer induction by impeding oxidative injury to DNA, these properties cannot account for apoptosis induction and chemotherapeutic observations. Catechin (C), epicatechin (EC), epigallocatechin (EGC) and epigallocatechin-3-gallate (EGCG) are the four major constituents of green tea. In this article, using human peripheral lymphocytes and comet assay, we show that C, EC, EGC and EGCG cause cellular DNA breakage and can alternatively switch to a prooxidant action in the presence of transition metals such as copper. The cellular DNA breakage was found to be significantly enhanced in the presence of copper ions. Catechins were found to be effective in providing protection against oxidative stress induced by tertbutylhydroperoxide, as measured by oxidative DNA breakage in lymphocytes. The prooxidant action of catechins involved production of hydroxyl radicals through redox recycling of copper ions. We also determined that catechins, particularly EGCG, inhibit proliferation of breast cancer cell line MDA-MB-231 leading to a prooxidant cell death. Since it is well established that tissue, cellular and serum copper levels are considerably elevated in various malignancies, cancer cells would be more subject to redox cycling between copper ions and catechins to generate reactive oxygen species (ROS) responsible for DNA breakage. Such a copper dependent prooxidant cytotoxic mechanism better explains the anticancer activity and preferential cytotoxicity of dietary phytochemicals against cancer cells.

  5. In vitro release of cupric ion from intrauterine devices: influence of frame, shape, copper surface area and indomethacin.

    Science.gov (United States)

    Zhang, Shuangshuang; Li, Ying; Yu, Panpan; Chen, Tong; Zhou, Weisai; Zhang, Wenli; Liu, Jianping

    2015-02-01

    The release of cupric ion from copper intrauterine device (Cu-IUD) in human uterus is essential for contraception. However, excessive cupric ion will cause cytotoxic effect. In this paper, we investigated the influence of device characteristics (frame, copper surface area, shape, copper type and indomethacin) on copper release for the efficacy and adverse effects vary with IUD types which may correlate to their different release behaviors. Nine types of Cu-IUDs were selected and incubated in simulated uterine fluid. They were paired for comparison based on the device properties and the release of cupric ion was determined by flame atomic absorption spectrometer for about 160 days. The result showed that there was a burst release during the first month and the release rate tends to slow down and become steady afterwards. In addition, the copper release was mainly influenced by frame, indomethacin and copper type (copper wire and copper sleeve) while the shape variation had little effect on copper release throughout the experiment. Moreover, the influence of copper surface area was only noticeable during the first month. These findings were seldom reported before and may provide some useful information for the design of Cu-IUDs.

  6. Fragmentation of copper current collectors in Li-ion batteries during spherical indentation

    Science.gov (United States)

    Wang, Hsin; Watkins, Thomas R.; Simunovic, Srdjan; Bingham, Philip R.; Allu, Srikanth; Turner, John A.

    2017-10-01

    Large, areal, brittle fracture of copper current collector foils has been observed by 3D x-ray computed tomography (XCT) of a spherically indented Li-ion cell. This fracture is hidden and non-catastrophic to a degree because the graphite layers deform plastically, and hold the materials together so that the cracks in the foils cannot be seen under optical and electron microscopy. The cracking of copper foils could not be immediately confirmed when the cell is opened for post-mortem examination. However, 3D XCT on the indented cell reveals "mud cracks" within the copper layer and an X-ray radiograph on a single foil of the Cu anode shows clearly that the copper foil has broken into multiple pieces. This failure mode of anodes in Li-ion cell has very important implications on the behavior of Li-ion cells under mechanical abuse conditions. The fragmentation of current collectors in the anode must be taken into consideration for the electrochemical responses which may lead to capacity loss and affect thermal runaway behavior of the cells.

  7. Copper(II) ions and the Alzheimer's amyloid-β peptide: Affinity and stoichiometry of binding

    Science.gov (United States)

    Tõugu, Vello; Friedemann, Merlin; Tiiman, Ann; Palumaa, Peep

    2014-10-01

    Deposition of amyloid beta (Aβ) peptides into amyloid plaques is the hallmark of Alzheimer's disease. According to the amyloid cascade hypothesis this deposition is an early event and primary cause of the disease, however, the mechanisms that cause this deposition remain elusive. An increasing amount of evidence shows that the interactions of biometals can contribute to the fibrillization and amyloid formation by amyloidogenic peptides. From different anions the copper ions deserve the most attention since it can contribute not only toamyloid formation but also to its toxicity due to the generation of ROS. In this thesis we focus on the affinity and stoichiometry of copper(II) binding to the Aβ molecule.

  8. Copper transport systems are involved in multidrug resistance and drug transport.

    Science.gov (United States)

    Furukawa, Tatsuhiko; Komatsu, Masaharu; Ikeda, Ryuji; Tsujikawa, Kazutake; Akiyama, Shin-ichi

    2008-01-01

    Copper is an essential trace element and several copper containing proteins are indispensable for such processes as oxidative respiration, neural development and collagen remodeling. Copper metabolism is precisely regulated by several transporters and chaperone proteins. Copper Transport Protein 1 (CTR1) selectively uptakes copper into cells. Subsequently three chaperone proteins, HAH1 (human atx1 homologue 1), Cox17p and CCS (copper chaperone for superoxide dismutase) transport copper to the Golgi apparatus, mitochondria and copper/zinc superoxide dismutase respectively. Defects in the copper transporters ATP7A and ATP7B are responsible for Menkes disease and Wilson's disease respectively. These proteins transport copper via HAH1 to the Golgi apparatus to deliver copper to cuproenzymes. They also prevent cellular damage from an excess accumulation of copper by mediating the efflux of copper from the cell. There is increasing evidence that copper transport mechanisms may play a role in drug resistance. We, and others, found that ATP7A and ATP7B are involved in drug resistance against the anti-tumor drug cis-diamminedichloroplatinum (II) (CDDP). A relationship between the expression of ATP7A or ATP7B in tumors and CDDP resistance is supported by clinical studies. In addition, the copper uptake transporter CTR1 has also been reported to play a role in CDDP sensitivity. Furthermore, we have recently found that the effect of ATP7A on drug resistance is not limited to CDDP. Using an ex vivo drug sensitivity assay, the histoculture drug response assay (HDRA), the expression of ATP7A in human surgically resected colon cancer cells correlated with sensitivity to 7-ethyl-10-hydroxy-camptothecin (SN-38). ATP7A-overexpressing cells are resistant to many anticancer drugs including SN-38, 7-ethyl-10-[4-(1-piperidino)-1-piperidino] carbonyloxycamptothecin (CPT-11), vincristine, paclitaxel, etoposide, doxorubicin (Dox), and mitoxantron. The mechanism by which ATP7A and copper

  9. The ligational behavior of an isatinic quinolyl hydrazone towards copper(II- ions

    Directory of Open Access Journals (Sweden)

    Mousa Marwa A

    2011-04-01

    Full Text Available Abstract Background The importance of the isatinic quinolyl hydrazones arises from incorporating the quinoline ring with the indole ring. Quinoline ring has therapeutic and biological activities whereas, the indole ring occurs in Jasmine flowers and Orange blossoms. As a ligand, the isatin moiety is potentially ambidentate and can coordinate the metal ions either through its lactam or lactim forms. In a previous study, the ligational behavior of a phenolic quinolyl hydrazone towards copper(II- ions has been studied. As continuation of our interest, the present study is planned to check the ligational behavior of an isatinic quinolyl hydrazone. Results New homo- and heteroleptic copper(II- complexes were obtained from the reaction of an isatinic quinolyl hydrazone (HL with several copper(II- salts viz. Clˉ, Brˉ, NO3ˉ, ClO4-, SO42- and AcO-. The obtained complexes have Oh, Td and D4h- symmetry and fulfill the strong coordinating ability of Clˉ, Brˉ, NO3ˉ and SO42- anions. Depending on the type of the anion, the ligand coordinates the copper(II- ions either through its lactam (NO3ˉ and ClO4- or lactim (the others forms. Conclusion The effect of anion for the same metal ion is obvious from either the geometry of the isolated complexes (Oh, Td and D4h or the various modes of bonding. Also, the obtained complexes fulfill the strong coordinating ability of Clˉ, Brˉ, NO3ˉ and SO42- anions in consistency with the donor ability of the anions. In case of copper(II- acetate, a unique homoleptic complex (5 was obtained in which the AcO- anion acts as a base enough to quantitatively deprotonate the hydrazone. The isatinic hydrazone uses its lactim form in most complexes.

  10. Blanch Resistant and Thermal Barrier NiAl Coating Systems for Advanced Copper Alloys

    Science.gov (United States)

    Raj, Sai V. (Inventor)

    2005-01-01

    A method of forming an environmental resistant thermal barrier coating on a copper alloy is disclosed. The steps include cleansing a surface of a copper alloy, depositing a bond coat on the cleansed surface of the copper alloy, depositing a NiAl top coat on the bond coat and consolidating the bond coat and the NiAl top coat to form the thermal barrier coating. The bond coat may be a nickel layer or a layer composed of at least one of copper and chromium-copper alloy and either the bond coat or the NiAl top coat or both may be deposited using a low pressure or vacuum plasma spray.

  11. Removal of copper, nickel, and zinc ions from electroplating rinse water

    Energy Technology Data Exchange (ETDEWEB)

    Revathi, Meyyappan; Saravanan, Mohan; Velan, Manickam [Department of Chemical Engineering, AC Tech, Anna University, Chennai, Tamil Nadu (India); Chiya, Ahmed Basha [Department of Chemical Engineering, Industrial Liaison Research Institute, Kyang Hee University, Gyeonggi (Korea, Republic of)

    2012-01-15

    Removal of copper, nickel, and zinc ions from synthetic electroplating rinse water was investigated using cationic exchange resin (Ceralite IR 120). Batch ion exchange studies were carried out to optimize the various experimental parameters (such as contact time, pH, and dosage). Influence of co-existing cations, chelating agent EDTA on the removal of metal ion of interest was also studied. Sorption isotherm data obtained at different experimental conditions were fitted with Langmuir, Freundlich, Redlich-Peterson, and Toth models. A maximum adsorption capacity of 164 mg g{sup -1} for Cu(II), 109 mg g{sup -1} for Ni(II), and 105 mg g{sup -1} for Zn(II) was observed at optimum experimental conditions according to Langmuir model. The kinetic data for metal ions adsorption process follows pseudo second-order. Presence of EDTA and co-ions markedly alters the metal ion removal. Continuous column ion exchange experiments were also conducted. The breakeven point of the column was obtained after recovering effectively several liters of rinse water. The treated rinse water could be recycled in rinsing operations. The Thomas and Adams-Bohart models were applied to column studies and the constants were evaluated. Desorption of the adsorbed metal ions from the resin column was studied by conducting a model experiments with Cu(II) ions loaded ion exchange resin column using sulfuric acid as eluant. A novel lead oxide coated Ti substrate dimensionally stable (DSA) anode was prepared for recovery of copper ions as metal foil from regenerated liquor by electro winning at different current densities (50-300 A cm{sup -2}). (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Survival in amoeba--a major selection pressure on the presence of bacterial copper and zinc resistance determinants? Identification of a "copper pathogenicity island".

    Science.gov (United States)

    Hao, Xiuli; Lüthje, Freja L; Qin, Yanan; McDevitt, Sylvia Franke; Lutay, Nataliya; Hobman, Jon L; Asiani, Karishma; Soncini, Fernando C; German, Nadezhda; Zhang, Siyu; Zhu, Yong-Guan; Rensing, Christopher

    2015-07-01

    The presence of metal resistance determinants in bacteria usually is attributed to geological or anthropogenic metal contamination in different environments or associated with the use of antimicrobial metals in human healthcare or in agriculture. While this is certainly true, we hypothesize that protozoan predation and macrophage killing are also responsible for selection of copper/zinc resistance genes in bacteria. In this review, we outline evidence supporting this hypothesis, as well as highlight the correlation between metal resistance and pathogenicity in bacteria. In addition, we introduce and characterize the "copper pathogenicity island" identified in Escherichia coli and Salmonella strains isolated from copper- and zinc-fed Danish pigs.

  13. A spectrophotometric method for the determination of zinc, copper, and cobalt ions in metalloproteins using Zincon.

    Science.gov (United States)

    Säbel, Crystal E; Neureuther, Joseph M; Siemann, Stefan

    2010-02-15

    Zincon (2-carboxy-2'-hydroxy-5'-sulfoformazylbenzene) has long been known as an excellent colorimetric reagent for the detection of zinc and copper ions in aqueous solution. To extend the chelator's versatility to the quantification of metal ions in metalloproteins, the spectral properties of Zincon and its complexes with Zn(2+), Cu(2+), and Co(2+) were investigated in the presence of guanidine hydrochloride and urea, two common denaturants used to labilize metal ions in proteins. These studies revealed the detection of metals to be generally more sensitive with urea. In addition, pH profiles recorded for these metals indicated the optimal pH for complex formation and stability to be 9.0. As a consequence, an optimized method that allows the facile determination of Zn(2+), Cu(2+), and Co(2+) with detection limits in the high nanomolar range is presented. Furthermore, a simple two-step procedure for the quantification of both Zn(2+) and Cu(2+) within the same sample is described. Using the prototypical Cu(2+)/Zn(2+)-protein superoxide dismutase as an example, the effectiveness of this method of dual metal quantification in metalloproteins is demonstrated. Thus, the spectrophotometric determination of metal ions with Zincon can be exploited as a rapid and inexpensive means of assessing the metal contents of zinc-, copper-, cobalt-, and zinc/copper-containing proteins.

  14. Fabrication of interfacial functionalized porous polymer monolith and its adsorption properties of copper ions

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jiaxi; Du, Zhongjie; Zou, Wei; Li, Hangquan; Zhang, Chen, E-mail: zhangch@mail.buct.edu.cn

    2014-07-15

    Highlights: • Interface functionalized PGMA porous monolith was fabricated. • The adsorption capacity of Cu{sup 2+} was 35.3 mg/g. • The effects of porous structure on the adsorption of Cu{sup 2+} were studied. • The adsorption behaviors of porous monolith were studied. - Abstract: The interfacial functionalized poly (glycidyl methacrylate) (PGMA) porous monolith was fabricated and applied as a novel porous adsorbent for copper ions (Cu{sup 2+}). PGMA porous material with highly interconnected pore network was prepared by concentrated emulsion polymerization template. Then polyacrylic acid (PAA) was grafted onto the interface of the porous monolith by the reaction between the epoxy group on PGMA and a carboxyl group on PAA. Finally, the porous monolith was interfacial functionalized by rich amount of carboxyl groups and could adsorb copper ions effectively. The chemical structure and porous morphology of the porous monolith were measured by Fourier transform infrared spectroscopy and scanning electron microscopy. Moreover, the effects of pore size distribution, pH value, co-existing ions, contacting time, and initial concentrations of copper ions on the adsorption capacity of the porous adsorbents were studied.

  15. Interaction of ions in water system containing copper-zinc alloy for boiler energy saving

    Institute of Scientific and Technical Information of China (English)

    MING Xing; LIANG Jinsheng; OU Xiuqin; TANG Qingguo; DING Yan

    2006-01-01

    Copper-zinc alloy element for boiler energy saving was put in the intake of simulated boiler system to investigate the interaction and transfer of ions in water system both theoretically and experimentally. The fouling was analyzed by scanning electron microscopy (SEM) and energy dispersive X-ray detector (EDX). The results show that the transfer of calcium and magnesium ions in heat-transfer-surface-water system is affected by zinc ions dissolved from the alloy because of primary battery reaction. Some calcium ions of calcium carbonate crystal are replaced by zinc ions, the growth of aragonite crystal nucleus is retarded, and the transition of calcium carbonate from aragonite to calcite is hampered.

  16. Electrochemical removal of copper ions from dilute solutions using packed bed electrode. Part І

    Directory of Open Access Journals (Sweden)

    I.A. Khattab

    2013-06-01

    Full Text Available Removal of some hazardous waste like copper from effluent streams has an industrial importance. In this field, this paper is directed towards electrochemical removal of copper ions from sulfate solution using packed bed electrode. The cathode packing is in static mode, consisted of graphite particles, with mean particle size equal to 0.125 cm. The high surface area of this cell is expected to give high current efficiency and removal percent. The effect of current density and liquid flow rate were tested. Experimental results obtained indicate that the efficiencies are in direct proportional with current density while inversely proportional with liquid flow rate. It was observed that, using this cell was effective in reducing copper concentration to less than 4 mg/l with R.E of 96.2% during 30 min electrolysis time.

  17. Disentangling metabolic pathways involved in copper resistance in Candida fukuyamaensis RCL-3 indigenous yeast.

    Science.gov (United States)

    Irazusta, Verónica; Michel, Lucas; de Figueroa, Lucía I C

    2016-07-01

    Candida fukuyamaensis RCL-3 yeast strain isolated from a copper filter plant is able to lower copper concentration in culture medium. In the present study, effect of copper in proteins expression and mechanisms involved in copper resistance were explored using comparative proteomics. Mono-dimensional gel electrophoresis revealed differential band expressions between cells grown with or without copper. 2-DE analysis of C. fukuyamaensis RCL-3 revealed that copper exposure produced at least an over-expression of 40 proteins. Sixteen proteins were identified and grouped in four categories according to their functions: glycolysis and ATP production, synthesis of proteins, oxidative stress response, and processing and transport of proteins. Integral membrane proteins and membrane-associated proteins were analyzed, showing nine protein bands over-expressed in Cu-supplemented medium. Four proteins were identified, namely nucleoporin pom152, elongation factor 2, copper chaperone Sod1 Ccs1, and eiosome component Lsp1. The proteomic analysis performed allowed the identification of different metabolic pathways and certain proteins involved in metal input and storage related to cell ability to bioremediate copper. These proteins and mechanisms could be used for future applications of C. fukuyamaensis RCL-3 in biotechnological processes such as remediation of heavy metals. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. The Microstructure and Wear Resistance of a Copper Matrix Composite Layer on Copper via Nitrogen-Shielded Arc Cladding

    Directory of Open Access Journals (Sweden)

    Yinan Li

    2016-12-01

    Full Text Available A TiN and TiN·Ti2Cu reinforced copper matrix composite layer was cladded onto a T3 copper substrate to improve the anti-wear performance of copper products by means of the nitrogen-shielded gas tungsten arc cladding method (N2-GTAC. Better than the traditional preparation method of TiN, the TiN particles in the cladding layer were in situ generated using N atoms of shielding gas and Ti atoms of pre-deposited metal powders. In addition, the composite phase TiN·Ti2Cu occurred in the cladding layer, which also had a positive effect on anti-wearing. As Ti increased, the amount and grain size of TiN·Ti2Cu and TiN increased as a result. The hardness of the cladding layer increased with the increasing amount of reinforced phase generated in the layer. The hardness of the layer reached a maximum of 410 HV, which is nearly 5.1 times greater than that of copper. The TiN·Ti2Cu- and TiN-reinforced phases improved the wear resistance of the cladding layers. The cladding layer with 15 wt % Ti had the longsest launch stage (600 s and the lowest fiction coefficient (0.56.

  19. Comparing copper resistance in two bryophytes: Mielichhoferia elongata Hornsch. versus Physcomitrella patens Hedw.

    Science.gov (United States)

    Sassmann, Stefan; Wernitznig, Stefan; Lichtscheidl, Irene K; Lang, Ingeborg

    2010-10-01

    The bryophyte Mielichhoferia elongata is known to occur on copper-rich substrate, but the exact resistance level remained to be determined by in vitro experiments. Here, we tested its copper tolerance in graded copper solutions and compared the results to the moss Physcomitrella patens that is not known to inhabit heavy metal sites. Our results confirm the survival of M. elongata in classical resistance experiments of up to 10 mM Cu-ethylenediaminetetraacetic acid (EDTA) solution. Interestingly, P. patens is equally resistant. Cultured on copper-enriched agar plates for over 5 weeks, P. patens survived even higher copper levels of up to 100 mM Cu-EDTA and an increment of growth was detected on all concentrations tested. Obviously, P. patens is able to withstand harmfully high levels of copper in both solution and substrate. In this short communication, we give a detailed description of the growth rates and discuss the results in comparison to other moss species and heavy metals.

  20. Free cupric ions in contaminated agricultural soils around a copper mine in eastern Nanjing City, China

    Institute of Scientific and Technical Information of China (English)

    LUO Xiao-san; ZHOU Dong-mei; WANG Yu-jun

    2006-01-01

    To determine the environmental free metal ion activity was a recent hot issue. A method to measure low-level free cupric ion activity in soil solution extracted with 0.01 mol/L KNO3 was developed by using cupric ion-selective electrode (ISE) and calibrating with Cu-buffer solution. Three copper buffers including iminodiacetic acid (IDA), ethylenediamine (EN), and glycine (Gly)were compared for calibrating the Cu-ISE curves in the range of free cupric ions (pCu2+) 7-13. The Cu-EN buffer showed the best electrode response and thus was applied as the calibration buffer. The pCu2+ of 39 contaminated agricultural soils around a copper mine was measured, ranging from 5.03 to 9.20. Most Cu in the soil solutions was found to be complexed with dissolved soil organic matters, averaging 98.1%. The proportion of free Cu2+ ions in the soil solutions decreased with the increasing of solution pH. Soluble Cu and free Cu2+ ions concentrations were analyzed by multiple linear regressions to evaluate the effects of soil properties on metal levels and speciation. The results showed that soil solution pH was the most significant factor influencing pCu2+ (with R2 value of 0.76), while not important for the soluble Cu concentration.

  1. Flotation of traces of silver and copper(II) ions with a methyl cellosolve solution of dithizone.

    Science.gov (United States)

    Hiraide, M; Mizuike, A

    1975-06-01

    Microgram quantities of silver and copper(II) ions in aqueous solutions are collected on dithizone precipitates, which are then floated with the aid of small nitrogen bubbles. This separation technique has been successfully applied to the atomic-absorption spectrophotometric determination of down to a tenth ppm of silver and copper in high-purity lead and zinc metals.

  2. Effects of copper oxide nanoparticles and copper ions to zebrafish (Danio rerio) cells, embryos and fry

    DEFF Research Database (Denmark)

    Thit, Amalie; Skjolding, Lars Michael; Selck, Henriette

    2017-01-01

    with similar concentration-response relationships, whereas only Cu ions affected fry mortality (24h LC50≈30μM, ≈2mgCuL-1 for Cu ions and no significant mortality observed at up to 200μM, 12.7mgCuL-1 for CuO NP). Both Cu forms increased fry swimming activity during light cycles and decreased activity during......) and fry locomotion. In the ZFL tests, no significant cytotoxicity (cell death, decreased metabolic or cell membrane integrity) was detected for either treatment, though both significantly affected reactive oxygen species (ROS) production. Embryo mortality was affected by both Cu ions and CuO NPs...... dark cycles: Cu ions had significant impact at lower concentrations than CuO NPs. The implications are that Cu ions generally are more toxic than CuO NPs to embryos and fry but there is a marked difference in toxicity among the different zebrafish model systems. Metal NPs release into the environment...

  3. Wear Resistance of Friction Pair of Metal Composite/Copper under Electric Current

    Science.gov (United States)

    Aleutdinova, M. I.; Fadin, V. V.; Rubtsov, V. Ye; Aleutdinov, K. A.

    2016-11-01

    Sliding of metal composites against copper counterbody under severe conditions (i.e. at the contact current density higher 50 A/cm2 and at high roughness of counterbody) is carried out. It is shown that the composite of composition of Cu-30% of graphite shows low wear resistance in these conditions. Higher wear resistance is inherent in the composites containing lead and bearing steel. Impregnation of these composites by industrial oil hasn't led to noticeable increase in wear resistance.

  4. Use of an ion gauge beam flux monitor for resistivity control in CuInSe2 grown by molecular beam epitaxy

    Science.gov (United States)

    Huang, C.-Y.; Morse, S. M.; Clark, A. H.; Kazmerski, L. L.

    1982-07-01

    A miniature ion gauge to set the copper, indium and selenium fluxes for the growth of CuInSe2 has been fabricated and employed onto CdS to form solar photovoltaic heterojunctions. Resistivities from 0.01 ohm cm n-type to 0.001 ohm cm p-type can be reliably achieved to within a factor of 10 of the desired value. The copper-to-indium arrival rate ratio is critical in determining the layer resistivity of p-type material, with a high copper-to-indium ratio generally giving low resistivity. The selenium arrival rate is also important, however, in that low selenium rates always lead to n-type layers, independent of the copper-to-indium arrival rate ratio.

  5. Biosorption of the Copper and Cadmium Ions - a Study through Adsorption Isotherms Analysis

    Directory of Open Access Journals (Sweden)

    Marcia T. Veit

    2007-10-01

    Full Text Available In this work, the biosorption process of copper-cadmium ions binary mixture by using marine algae Sargassum filipendula was investigated. A set of experiments was performed to obtain equilibrium data for the given batch operational conditions - T=30°C, pH=5. The interpretation of equilibrium data was based on the binary adsorption isotherms models in the Langmuir and Freundlich forms. To evaluate the models parameters, nonlinear identification procedure was used based on the Least Square statistical method and SIMPLEX local optimizer. An analysis of the obtained results showed that the marine algae biomass has higher affinity to copper ions than to cadmium ones. The biomass maximum adsorption capacity for the binary system was about 1.16 meq/g.

  6. Irradiation damage in aluminium single crystals produced by 50-keV aluminium and copper ions

    DEFF Research Database (Denmark)

    Henriksen, L.; Johansen, A.; Koch, J.

    1968-01-01

    Aluminium single crystals, thin enough to be examined by electron microscopy, have been irradiated with 50-keV aluminium and copper ions. The irradiation fluxes were in the range 1011–1014 cm−2 s−1 and the doses were from 6 × 1012 to 6 × 1014 cm−2. Irradiation along either a or a direction produc...

  7. Effect of Phosphorylation and Copper(II or Iron(II Ions Enrichment on Some Physicochemical Properties of Spelt Starch

    Directory of Open Access Journals (Sweden)

    Jacek Rożnowski

    Full Text Available ABSTRACT: This paper provides an assessment of the effect of saturation of spelt starch and monostarch phosphate with copper or iron ions on selected physicochemical properties of the resulting modified starches. Native and modified spelt starch samples were analyzed for selected mineral element content using Atomic Absorption Spectroscopy (AAS. Thermodynamic properties were measured using DSC, and pasting properties by RVA. Flow curves of 5% pastes were plotted and described using the Herschel-Bulkley model. The structure recovery ratio was measured. AAS analysis established the presence of iron(II and copper(II ions in the samples of modified starches and that potassium and magnesium ions had leached from them. In comparison to unfortified samples, enriching native starch with copper(II ions decreases value of all temperatures of phase transformation about 1.3-2.7 °C, but in case of monostarch phosphates bigger changes (2.8-3.7 °C were observed. Fortified native spelt starch with copper(II ions caused increasing the final viscosity of paste from 362 to 429 mPa·s. However, presence iron(II ions in samples caused reduced its final viscosity by 170 (spelt starch and 103 mPa·s (monostarch phosphate. Furthermore, enriching monostarch phosphate contributed to reduce degree of structure recovery of pastes from 70.9% to 66.6% in case of copper(II ions and to 59.9% in case of iron(II ions.

  8. Synthesis and evaluation of a new colorimetric and ratiometric fluorescence probe for copper ions

    Energy Technology Data Exchange (ETDEWEB)

    Chawla, Har Mohindra, E-mail: hmchawla@chemistry.iitd.ernet.in; Munjal, Priyanka; Goel, Preeti

    2015-08-15

    Synthesis and spectroscopic evaluation of compounds 3a, 3b and 4 reveal that cone conformer of 25,27-bis(o-aminothiophenyl propyloxy) -tetra-p-tert-butylcalix[4]arene 3a can function as a highly selective ratiometric and colorimetric fluorescence probe for copper ions. - Highlights: • We have synthesized a new calixarene based receptor 3 for Cu{sup 2+}. • 3 Showed ratiometric changes with Cu{sup 2+} in emission spectrum. • Reference compound 4 showed quenching with Cu{sup 2+} in emission spectrum. • Importance of calix[4]arene platform in ion recognition.

  9. Electrochemical determination of copper ions in spirit drinks using carbon paste electrode modified with biochar.

    Science.gov (United States)

    Oliveira, Paulo Roberto; Lamy-Mendes, Alyne C; Rezende, Edivaltrys Inayve Pissinati; Mangrich, Antonio Sálvio; Marcolino, Luiz Humberto; Bergamini, Márcio F

    2015-03-15

    This work describes for first time the use of biochar as electrode modifier in combination with differential pulse adsorptive stripping voltammetric (DPAdSV) techniques for preconcentration and determination of copper (II) ions in spirit drinks samples (Cachaça, Vodka, Gin and Tequila). Using the best set of the experimental conditions a linear response for copper ions in the concentration range of 1.5 × 10(-6) to 3.1 × 10(-5) mol L(-1) with a Limit of Detection (LOD) of 4.0 × 10(-7) mol L(-1). The repeatability of the proposed sensor using the same electrode surface was measured as 3.6% and 6.6% using different electrodes. The effect of foreign species on the voltammetric response was also evaluated. Determination of copper ions content in different samples of spirit drinks samples was also realized adopting inductively coupled plasma optical emission spectroscopy (ICP-OES) and the results achieved are in agreement at a 95% of confidence level.

  10. Synergistic inhibition effect of benzotriazole (BTA) and oxalate ions on the corrosion of copper, zinc and brass in NaCl and HCl solutions

    Energy Technology Data Exchange (ETDEWEB)

    Yanardag, T.; Aksut, A.A. [Ankara Univ., Science Faculty, Dept. of Chemistry, Ankara (Turkey)

    2009-07-01

    Inhibition of corrosion is of high technological importance and progress made in this field has been phenomenal in recent years. Zinc is more active compared to copper. Copper is a valuable material, especially in electronics, solar cell fittings, household products, structural engineering, art and decoration, coinage and biomedical application. Even though copper is corrosion resistant due to its natural oxide film, it is prone to corrode in solutions that contain oxygen and high concentration of chloride, sulphate, sulphide and nitrate ions. A variety of potentially damaging environments require versatile inhibition actions. Although an inhibitor is sometimes added to avoid tarnishing, in the majority of cases the inhibitor's purpose is to prevent or postpone corrosion attack. The corrosion inhibition of copper, zinc and brass in 0.5 M NaCl and 0.5 M HCl solutions in the presence of BTA and sodium oxalate have been investigated using polarization, AC-impedance and current-potential methods. Inhibition effect depends to the pretreatment of electrode. For this reason, the electrodes were pretreated in 0.15 M HCl solution for 20 seconds in order to obtain better surface prone to form coatings on the electrode surface before immersing into the studied solutions. Results showed BTA and oxalate to have synergistic inhibition effect on the corrosion of copper and brass. All the methods employed showed good correlation between each other revealing a mean efficiency of 99% in neutral medium and 88% in acidic medium for brass. (authors)

  11. Polyacrylamide hydrogel encapsulated E. coli expressing metal-sensing green fluorescent protein as a potential tool for copper ion determination.

    Science.gov (United States)

    Tantimongcolwat, Tanawut; Isarankura-Na-Ayudhya, Chartchalerm; Srisarin, Apapan; Galla, Hans-Joachim; Prachayasittikul, Virapong

    2014-01-01

    A simple, inexpensive and field applicable metal determination system would be a powerful tool for the efficient control of metal ion contamination in various sources e.g. drinking-water, water reservoir and waste discharges. In this study, we developed a cell-based metal sensor for specific and real-time detection of copper ions. E. coli expressing metal-sensing green fluorescent protein (designated as TG1/(CG)6GFP and TG1/H6CdBP4GFP) were constructed and served as a metal analytical system. Copper ions were found to exert a fluorescence quenching effect, while zinc and cadmium ions caused minor fluorescence enhancement in the engineered bacterial suspension. To construct a user-friendly and reagentless metal detection system, TG1/H6CdBP4GFP and TG1/(CG)6GFP were encapsulated in polyacrylamide hydrogels that were subsequently immobilized on an optical fiber equipped with a fluorescence detection module. The sensor could be applied to measure metal ions by simply dipping the encapsulated bacteria into a metal solution and monitoring fluorescence changes in real time as a function of the metal concentration in solution. The sensor system demonstrated high specificity toward copper ions. The fluorescence intensities of the encapsulated TG1/(CG)6GFP and TG1/H6CdBP4GFP were quenched by approximately 70 % and 80 % by a high-dose of copper ions (50 mM), respectively. The level of fluorescence quenching exhibited a direct correlation with the copper concentration, with a linear correlation coefficient (r) of 0.99. The cell-based metal sensor was able to efficiently monitor copper concentrations ranging between 5 M and 50 mM, encompassing the maximum allowed copper contamination in drinking water (31.15 M) established by the WHO. Furthermore, the cell-based metal sensor could undergo prolonged storage for at least 2 weeks without significantly influencing the copper sensitivity.

  12. Corrosion and biofouling resistance evaluation of 90-10 copper-nickel

    Energy Technology Data Exchange (ETDEWEB)

    Powell, Carol [Consultant to Copper Development Association, UK, Square Covert, Caynham, Ludlow, Shropshire (United Kingdom)

    2004-07-01

    Copper-nickel alloys for marine use were developed for naval applications in the early part of the 20. century with a view to improving the corrosion resistance of condenser tubes and seawater piping. They still enjoy widespread use today not only for many navies but also in commercial shipping, floating production, storage and off loading vessels (FPSOs), and in multistage flash desalination. The two popular alloys contain 90% or 70% copper and differ in strength and maximum sea water velocity levels they can handle but it is the 90-10 copper-nickel (CuNi10Fe1Mn) which is the more economic and extensively used. An additional benefit of this alloy is its high resistance to biofouling: in recent years this has led to sheathing developments particularly for structures and boat hulls. This paper provides a review of the corrosion and biofouling resistance of 90-10 copper-nickel based on laboratory test data and documented experience of the alloy in marine environments. Particular attention is given to exposure trials over 8 years in Langstone Harbour, UK, which have recently been completed by Portsmouth University on behalf of the Nickel Institute. These examined four sheathing products; plate and foil as well as two composite products with rubber backing. The latter involved copper-nickel granules and slit sheet. The trial results are consistent with the behaviour of the alloy in the overall review. There is an inherent high resistance to marine biofouling when freely exposed. Prolonged exposure to quiet conditions can result in some growth of marine organisms but this is loosely attached and can readily be removed by wiping or a light scraping. The good corrosion resistance of 90-10 copper-nickel in sea water is also confirmed and associated with the formation of a thin, complex, protective and predominantly cuprous oxide surface film, which forms and matures naturally on exposure to seawater. Sound initial oxide film formation is also known to help protect against

  13. Reduction of microbial pathogens during apple cider production using sodium hypochlorite, copper ion, and sonication.

    Science.gov (United States)

    Rodgers, Stephanie L; Ryser, Elliot T

    2004-04-01

    Sodium hypochlorite (100 ppm), copper ion water (1 ppm), and sonication (22 to 44 kHz and 44 to 48 kHz) were assessed individually and in combination for their ability to reduce populations of Escherichia coli O157:H7 and Listeria monocytogenes on apples and in apple cider. Commercial unpasteurized cider was inoculated to contain approximately 10(6) CFU/ml of either pathogen and then sonicated at 44 to 48 kHz, with aliquots removed at intervals of 30 to 60 s for up to 5 min and plated to determine numbers of survivors. Subsequently, whole apples were inoculated by dipping to contain approximately 10(6) CFU/g E. coli O157:H7 or L. monocytogenes, held overnight, and then submerged in 1 ppm copper ion water with or without 100 ppm sodium hypochlorite for 3 min with or without sonication at 22 to 44 kHz and examined for survivors. Treated apples were also juiced, with the resulting cider sonicated for 3 min. Populations of both pathogens decreased 1 to 2 log CFU/ml in inoculated cider following 3 min of sonication. Copper ion water alone did not significantly reduce populations of either pathogen on inoculated apples. However, when used in combination with sodium hypochlorite, pathogen levels decreased approximately 2.3 log CFU/g on apples. Sonication of this copper ion-sodium hypochlorite solution at 22 to 44 kHz did not further improve pathogen reduction on apples. Numbers of either pathogen in the juice fraction were approximately 1.2 log CFU/ml lower after being juiced, with sonication (44 to 48 kHz) of the expressed juice decreasing L. monocytogenes and E. coli O157:H7 populations an additional 2 log. Hence, a 5-log reduction was achievable for both pathogens with the use of copper ion water in combination with sodium hypochlorite followed by juicing and sonication at 44 to 48 kHz.

  14. Extraction of copper ions by supercritical carbon dioxide

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Complexation combined with supercritical fluid extraction was used to extract Cu2+ in this study. The effects of pressure, temperature, volume of CO2 on the efficiency of extraction were systematically investigated. At the optimum condition a 57.32% recovery was achieved. Addition of suitable amount of methanol(v/v = 5 % ) to the supercritical CO2 can increase in the extraction of Cu2+ (72.69 %, RSD = 2.12 %, n = 3). And the recovery can further increase in the presence of non-ionic surfactant Triton X-100 because of its function of solubilization. Surfactant was first used in the extraction of metal ions in the present study, and the results are satisfied (90.52%, RSD=2.20%, n =3).

  15. Size-Controlled Synthesis of Copper Oxide Particles on Reduced Graphene Oxide for Lithium-Ion Battery Anode Applications.

    Science.gov (United States)

    Jang, Haneul; Kim, Kyungbae; Chang, Hyejung; Kim, Jae-Hun; Choi, Hyunjoo

    2015-11-01

    Copper oxide/reduced graphene oxide (rGO) hybrids have been successfully synthesized by attaching copper ions onto the functional groups of GO by means of a solution process, which causes precipitation and agglomeration of copper oxides during subsequent thermal reduction of the GO. The resulting copper oxide/rGO hybrid exhibited improved electrochemical performance compared to monolithic CuO, which is presumed to be due to rGO acting as a mechanical support that buffers the volume change in copper oxides that occurs as a result of the conversion reaction during charge/discharge cycling. Furthermore, it was found that the size of the copper oxide particles can be optimized by adjusting the annealing time, with a hybrid annealed for 30 min achieving a reversible capacity of 544 mA h g(-1) and an initial coulombic efficiency of 62.7%.

  16. Montmorillonite modified with copper ions: Efficient adsorbent for aflatoxin B1

    Directory of Open Access Journals (Sweden)

    Daković Aleksandra

    2008-01-01

    Full Text Available In this paper, the results of preparation of material for adsorption of aflatoxin B1, based on modification of montmorillonite with copper ions (Cu-MONT, are presented. The bentonite clay from Sokolac deposit (Šipovo, Bosnia was used as the starting raw material. After modification of concentrate of montmorillonite (MONT with copper, the content of copper in Cu-MONT, was 2.65%. It was shown that MONT, as well as the Cu-MONT were efficient in adsorption of aflatoxin B1, at different mass ratios of adsorbent : toxin, and at different pH values. It was determined that for MONT, at the mass ratio adsorbent : toxin = 5000 : 1, aflatoxin B1 adsorption index was 100% at pH 3, 98% at pH 7 and 96% at pH 9. For Cu-MONT, at the same mass ratio, the following aflatoxin B1 adsorption indexes were achieved: 98% at pH 3, 98% at pH 7 and 96% at pH 9. No differences in adsorption of this toxin by both montmorillonites with decreasing the mass ratio of adsorbent : toxin (250 : 1 were observed. That means that ion exchange of inorganic cations in montmorillonite with copper ions did not cause any changes in aflatoxin B1 adsorption, at pH 3, as well as at pH 7 and 9. It was also noticed that adsorption of aflatoxin B1 by MONT and Cu-MONT was not pH dependent.

  17. Strategy for copper speciation in white wine by differential pulse anodic stripping voltammetry, potentiometry with an ion-selective electrode and kinetic photometric determination

    Energy Technology Data Exchange (ETDEWEB)

    Wiese, C. [Inst. fuer Anorganische und Analytische Chemie, Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany); Schwedt, G. [Inst. fuer Anorganische und Analytische Chemie, Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany)

    1997-07-01

    Differential pulse anodic stripping voltammetry (DPASV), potentiometry with a copper ion-selective electrode and a kinetic photometric method were used to determine copper species in white wines. The kinetic method is based on the catalytic effect of labile copper(II) species on the oxidation of 3-hydroxybenzaldehyde azine by potassium peroxidisulfate in an ammonical medium at room temperature. The total copper concentrations were determined by flame atomic absorption spectrometry. Free copper(II) ions, labile and tightly bound copper species could be quantified in 16 non pre-treated wine samples. (orig.). With 3 figs., 5 tabs.

  18. Characterization of copper-resistant agrobacterium isolated from legume nodule in mining tailings.

    Science.gov (United States)

    Yu, Jianfu; Fan, Lianmei; Yang, Shushen; Tang, Ming; Yang, Wenquan; Li, Huifen; Wei, Gehong

    2009-03-01

    A copper-resistant bacteria CCNWSX2332 was isolated from root nodules of Lespedeza cuneata growing in a gold mining tailing region in northwest of China. The specific growth rate of the strain was 0.62 microh(-1) in the presence of 2.0 mM Cu(2+) in TY liquid media, and the maximum copper accumulation of whole cell reached 147.03 microM Cu(2+) per gram (dry weight) after 4 h incubation. A partial sequence of the copper resistance gene copA was amplified from the strain, and the phylogenetic analysis based on 16S rDNA sequence showed that CCNWSX2332 belonged to Agrobacterium, and it had 100% similarity with Agrobacterium tumefaciens type strain IAM13129(T).

  19. Effect of Mo Ion Implantation on Stability of Nanocrystalline Copper Surface Layers

    Directory of Open Access Journals (Sweden)

    XI Yang

    2016-08-01

    Full Text Available The surface of pure copper was modified using the surface mechanical attrition treatment (SMAT method, and molybdenum ions were implanted in the nanosurface using a metal vapor vacuum arc (MEVVA. The results of the SMAT were observed by optical microscopy (OM, X-ray diffraction (XRD and scanning electron microscopy (SEM. An obvious nanocrystalline layer and a deformation region exist on the surface. The size of the nanocrystalline layer was characterized using atomic force microscopy (AFM. The results indicate remarkable suppression on grain size, the nanocrystalline layer grows to 163nm after annealing and reduces to only 72nm due to the Mo ion implantation. In addition, the hardness of the topmost surface of the material is 3.5 times that of the SMATed copper, which is about 7 times of the value of the matrix. The above improvements most likely result from the dispersion of the Mo ions and the reactions of the crystal defects due to the SMAT and ion implantation.

  20. Two different modes for copper(II ion coordination to quinine-type ligands

    Directory of Open Access Journals (Sweden)

    Rey Nicolás A.

    2006-01-01

    Full Text Available Three new copper(II complexes with the ligands quinuclidine [Cu(C7H13N2(OH2Cl]Cl.2H 2O (1, quinine [Cu(C20H23O2N2(OH 22]ClO4 (2, and hydroquinidine [Cu(C20H27O2N2(OH 2 Cl2]Cl.fraction one-halfH2O (3 have been isolated and characterized. The binding sites were assigned on the basis of vibrational spectroscopy, electron paramagnetic resonance, and thermal analysis results. The possibility of the involvement of the quinuclidinic nitrogen in the coordination was evidenced in complex 1, in which copper(II is coordinated to two quinuclidine molecules. In the case of quinine-type ligands, if the starting material is deprotonated in both nitrogens, copper(II coordination occurs through the quinuclidinic nitrogen, as in complex 2. In contrast, if the starting material is protonated in the quinuclidinic nitrogen the binding site is the quinolinic nitrogen, as in complex 3. Therefore, both nitrogens of quinine-type ligands constitute binding sites for copper(II ions.

  1. Immobilization of Magnetic Nanoparticles onto Amine-Modified Nano-Silica Gel for Copper Ions Remediation

    Directory of Open Access Journals (Sweden)

    Marwa Elkady

    2016-06-01

    Full Text Available A novel nano-hybrid was synthesized through immobilization of amine-functionalized silica gel nanoparticles with nanomagnetite via a co-precipitation technique. The parameters, such as reagent concentrations, reaction temperature and time, were optimized to accomplish the nano-silica gel chelating matrix. The most proper amine-modified silica gel nanoparticles were immobilized with magnetic nanoparticles. The synthesized magnetic amine nano-silica gel (MANSG was established and characterized using X-ray diffraction (XRD, transmission electron microscopy (TEM, scanning electron microscopy (SEM, Fourier transform infrared (FTIR, thermal gravimetric analysis (TGA, differential scanning calorimetry (DSC and vibrating sample magnetometry (VSM. The feasibility of MANSG for copper ions’ remediation from wastewater was examined. MANSG achieves a 98% copper decontamination from polluted water within 90 min. Equilibrium sorption of copper ions onto MANSG nanoparticles obeyed the Langmuir equation compared to the Freundlich, Temkin, Elovich and Dubinin-Radushkevich (D-R equilibrium isotherm models. The pseudo-second-order rate kinetics is appropriate to describe the copper sorption process onto the fabricated MANSG.

  2. THE EFFECTS OF COPPER AND ZINC IONS DURING THEIR BINDING WITH HUMAN SERUM γ-GLOBULIN

    Directory of Open Access Journals (Sweden)

    S. B. Cheknev

    2006-01-01

    Full Text Available Abstract. Conformational changes of human serum γ-globulin were studied during and after its binding with copper and zinc ions, using molecular ultrafiltration and differential spectrophotometry. The contents of nonbound metals in the filtrate were evaluated, resp., with sodium diethyl thyocarbamate and o-phenanthroline. It has been shown that copper and zinc exhibited common biological properties during their interactions with protein, but the binding differed sufficiently under similar experimental conditions. E.g., it was confirmed that copper was more active at the external sites of γ-globulin molecule, whereas zinc demonstrated tropicity for the areas of protein intraglobular compartments. The metal-binding sites have been described that differ in their parameters of interactions with cations and their spatial location within globular domains. Approaches are suggested for dynamic analysis of saturation for these differently located sites by the metal ions. We discuss the issues of altered conformational state of the γ-globulin molecule during the binding of cations, as well as potential usage of these data in clinical immunology.

  3. Ion exchange in KTiOPO4 crystals irradiated by copper and hydrogen ions.

    Science.gov (United States)

    Zhang, Ruifeng; Lu, Fei; Lian, Jie; Liu, Hanping; Liu, Xiangzhi; Lu, Qingming; Ma, Hongji

    2008-05-12

    Cs(+)-K+ ion exchanges were produced on KTiOPO4 crystals which is prior irradiated by Cu+ can H+ ions. The energy and dose of implanted Cu+ ions are 1.5 MeV and 0.5 x 10(14) ions/cm2, and that of H+ are 300 keV and 1 x 10(16) ions/cm2, respectively. The temperature of ions exchange is 430 degrees C, and the time range from 15 minutes to 30 minutes. The prism coupling method is used to measure the dark mode spectra of the samples. Compared with results of ion exchange on the sample without irradiations, both the number of guided mode and its corresponding effective refractive index are decreased. The experimental results indicate that the ion exchange rate closely related with the lattice damage and the damage layers formed in the depth of maximum nuclear energy deposition act as a barrier to block the ions diffuse into the sample and the concentration of defects can modify the speed of ion exchange..

  4. Genome sequences of copper resistant and sensitive Enterococcus faecalis strains isolated from copper-fed pigs in Denmark

    DEFF Research Database (Denmark)

    Zhang, Siyu; Wang, Dan; Wang, Yihua;

    2015-01-01

    Six strains of Enterococcus faecalis (S1, S12, S17, S18, S19 and S32) were isolated from copper fed pigs in Denmark. These Gram-positive bacteria within the genus Enterococcus are able to survive a variety of physical and chemical challenges by the acquisition of diverse genetic elements....... The genome of strains S1, S12, S17, S18, S19 and S32 contained 2,615, 2,769, 2,625, 2,804, 2,853 and 2,935 protein-coding genes, with 41, 42, 27, 42, 32 and 44 genes encoding antibiotic and metal resistance, respectively. Differences between Cu resistant and sensitive E. faecalis strains, and possible co...

  5. Membrane Anchoring and Ion-Entry Dynamics in P-type ATPase Copper Transport

    DEFF Research Database (Denmark)

    Grønberg, Christina; Sitsel, Oleg; Lindahl, Erik

    2016-01-01

    Cu(+)-specific P-type ATPase membrane protein transporters regulate cellular copper levels. The lack of crystal structures in Cu(+)-binding states has limited our understanding of how ion entry and binding are achieved. Here, we characterize the molecular basis of Cu(+) entry using molecular......-dynamics simulations, structural modeling, and in vitro and in vivo functional assays. Protein structural rearrangements resulting in the exposure of positive charges to bulk solvent rather than to lipid phosphates indicate a direct molecular role of the putative docking platform in Cu(+) delivery. Mutational analyses...... and simulations in the presence and absence of Cu(+) predict that the ion-entry path involves two ion-binding sites: one transient Met148-Cys382 site and one intramembranous site formed by trigonal coordination to Cys384, Asn689, and Met717. The results reconcile earlier biochemical and x-ray absorption data...

  6. Rapid determination of trace level copper in tea infusion samples by solid contact ion selective electrode

    Directory of Open Access Journals (Sweden)

    Aysenur Birinci

    2016-07-01

    Full Text Available A new solid contact copper selective electrode with a poly (vinyl chloride (PVC membrane consisting of o-xylylenebis(N,N-diisobutyldithiocarbamate as ionophore has been prepared. The main novelties of constructed ion selective electrode concept are the enhanced robustness, cheapness, and fastness due to the use of solid contacts. The electrode exhibits a rapid (< 10 seconds and near-Nernstian response to Cu2+ activity from 10−1 to 10−6 mol/L at the pH range of 4.0–6.0. No serious interference from common ions was found. The electrode characterizes by high potential stability, reproducibility, and full repeatability. The electrode was used as an indicator electrode in potentiometric titration of Cu(II ions with EDTA and for the direct assay of tea infusion samples by means of the calibration graph technique. The results compared favorably with those obtained by the atomic absorption spectroscopy (AAS.

  7. Molecular basis of active copper resistance mechanisms in Gram-negative bacteria.

    Science.gov (United States)

    Bondarczuk, Kinga; Piotrowska-Seget, Zofia

    2013-12-01

    Copper is a metallic element that is crucial for cell metabolism; however, in extended concentrations, it is toxic for all living organisms. The dual nature of copper has forced organisms, including bacteria, to keep a tight hold on cellular copper content. This challenge has led to the evolution of complex mechanisms that on one hand enable them to deliver the essential element and on the other to protect cells against its toxicity. Such mechanisms have been found in both eukaryotic and prokaryotic cells. In bacteria a number of different systems such as extra- and intracellular sequestration, enzymatic detoxification, and metal removal from the cell enabling them to survive in the presence of high concentration of copper have been identified. Gram-negative bacteria, due to their additional compartment, need to deal with both cytoplasmic and periplasmic copper. Therefore, these bacteria have evolved intricate and precisely regulated systems which interact with each other. In this review the active mechanisms of copper resistance at their molecular level are discussed.

  8. Influence of copper ions on the viability and cytotoxicity of Pseudomonas aeruginosa under conditions relevant to drinking water environments.

    Science.gov (United States)

    Dwidjosiswojo, Zenyta; Richard, Jessica; Moritz, Miriam M; Dopp, Elke; Flemming, Hans-Curt; Wingender, Jost

    2011-11-01

    Copper plumbing materials can be the source of copper ions in drinking water supplies. The aim of the current study was to investigate the influence of copper ions on the viability and cytotoxicity of the potential pathogen Pseudomonas aeruginosa that presents a health hazard when occurring in building plumbing systems. In batch experiments, exposure of P. aeruginosa (10(6)cells/mL) for 24h at 20°C to copper-containing drinking water from domestic plumbing systems resulted in a loss of culturability, while total cell numbers determined microscopically did not decrease. Addition of the chelator diethyldithiocarbamate (DDTC) to copper-containing water prevented the loss of culturability. When suspended in deionized water with added copper sulfate (10 μM), the culturability of P. aeruginosa decreased by more than 6 log units, while total cell counts, the concentration of cells with intact cytoplasmic membranes, determined with the LIVE/DEAD BacLight kit, and the number of cells with intact 16S ribosomal RNA, determined by fluorescent in situ hybridization, remained unchanged. When the chelator DDTC was added to copper-stressed bacteria, complete restoration of culturability was observed to occur within 14 d. Copper-stressed bacteria were not cytotoxic towards Chinese hamster ovary (CHO-9) cells, while untreated and resuscitated bacteria caused an almost complete decrease of the concentration of viable CHO-9 cells within 24 h. Thus, copper ions in concentrations relevant to drinking water in plumbing systems seem to induce a viable but non-culturable (VBNC) state in P. aeruginosa accompanied by a loss of culturability and cytotoxicity, and VBNC cells can regain both culturability and cytotoxicity, when copper stress is abolished.

  9. Development and tests of molybdenum armored copper components for MITICA ion source

    Science.gov (United States)

    Pavei, Mauro; Böswirth, Bernd; Greuner, Henri; Marcuzzi, Diego; Rizzolo, Andrea; Valente, Matteo

    2016-02-01

    In order to prevent detrimental material erosion of components impinged by back-streaming positive D or H ions in the megavolt ITER injector and concept advancement beam source, a solution based on explosion bonding technique has been identified for producing a 1 mm thick molybdenum armour layer on copper substrate, compatible with ITER requirements. Prototypes have been recently manufactured and tested in the high heat flux test facility Garching Large Divertor Sample Test Facility (GLADIS) to check the capability of the molybdenum-copper interface to withstand several thermal shock cycles at high power density. This paper presents both the numerical fluid-dynamic analyses of the prototypes simulating the test conditions in GLADIS as well as the experimental results.

  10. Development and tests of molybdenum armored copper components for MITICA ion source

    Energy Technology Data Exchange (ETDEWEB)

    Pavei, Mauro, E-mail: mauro.pavei@igi.cnr.it; Marcuzzi, Diego; Rizzolo, Andrea; Valente, Matteo [Consorzio RFX, Corso Stati Uniti, 4, I-35127 Padova (Italy); Böswirth, Bernd; Greuner, Henri [Max-Planck-Institut für Plasmaphysik, Boltzmannstrasse 2, D-85748 Garching (Germany)

    2016-02-15

    In order to prevent detrimental material erosion of components impinged by back-streaming positive D or H ions in the megavolt ITER injector and concept advancement beam source, a solution based on explosion bonding technique has been identified for producing a 1 mm thick molybdenum armour layer on copper substrate, compatible with ITER requirements. Prototypes have been recently manufactured and tested in the high heat flux test facility Garching Large Divertor Sample Test Facility (GLADIS) to check the capability of the molybdenum-copper interface to withstand several thermal shock cycles at high power density. This paper presents both the numerical fluid-dynamic analyses of the prototypes simulating the test conditions in GLADIS as well as the experimental results.

  11. Non-invasive nano-imaging of ion implanted and activated copper in silicon

    Science.gov (United States)

    Ballout, Fouad; Samson, Jean-Sébastien; Schmidt, Diedrich A.; Bründermann, Erik; Mathis, Yves-Laurent; Gasharova, Biliana; Dirk Wieck, Andreas; Havenith, Martina

    2011-07-01

    Using vibrational imaging techniques including Fourier-transform infrared (FTIR) synchrotron microscopy, Raman microscopy, and scattering scanning near-field infrared microcscopy (s-SNIM), we mapped a sample of phosphor and copper ions implanted in a high-purity silicon wafer. While Raman microscopy monitors the structural disorder within the implantation fields, the aforementionedinfrared techniques provide a detailed picture of the distribution of the free carriers. On a large scale (tens of micrometers), we visualized the channeling effects of phosphor dopants in silicon using FTIR microscopy. In comparison, using s-SNIM we were able to image, on a nanometer scale, local variations of the dielectric properties of the silicon substrate due to the activation of copper dopants.

  12. Copper pollution decreases the resistance of soil microbial community to subsequent dry-rewetting disturbance.

    Science.gov (United States)

    Li, Jing; Wang, Jun-Tao; Hu, Hang-Wei; Ma, Yi-Bing; Zhang, Li-Mei; He, Ji-Zheng

    2016-01-01

    Dry-rewetting (DW) disturbance frequently occurs in soils due to rainfall and irrigation, and the frequency of DW cycles might exert significant influences on soil microbial communities and their mediated functions. However, how microorganisms respond to DW alternations in soils with a history of heavy metal pollution remains largely unknown. Here, soil laboratory microcosms were constructed to explore the impacts of ten DW cycles on the soil microbial communities in two contrasting soils (fluvo-aquic soil and red soil) under three copper concentrations (zero, medium and high). Results showed that the fluctuations of substrate induced respiration (SIR) decreased with repeated cycles of DW alternation. Furthermore, the resistance values of substrate induced respiration (RS-SIR) were highest in non-copper-stressed (zero) soils. Structural equation model (SEM) analysis ascertained that the shifts of bacterial communities determined the changes of RS-SIR in both soils. The rate of bacterial community variance was significantly lower in non-copper-stressed soil compared to the other two copper-stressed (medium and high) soils, which might lead to the higher RS-SIR in the fluvo-aquic soil. As for the red soil, the substantial increase of the dominant group WPS-2 after DW disturbance might result in the low RS-SIR in the high copper-stressed soil. Moreover, in both soils, the bacterial diversity was highest in non-copper-stressed soils. Our results revealed that initial copper stress could decrease the resistance of soil microbial community structure and function to subsequent DW disturbance.

  13. Recovery of electrical resistance in copper films on polyethylene terephthalate subjected to a tensile strain

    Energy Technology Data Exchange (ETDEWEB)

    Glushko, O. [Department Materials Physics, Montanuniversität Leoben, Jahnstrasse 12, 8700 Leoben (Austria); Marx, V.M.; Kirchlechner, C. [Department Materials Physics, Montanuniversität Leoben, Jahnstrasse 12, 8700 Leoben (Austria); Max-Plank-Institut für Eisenforschung GmbH, Max-Planck-Strasse 1, 40237 Düsseldorf (Germany); Zizak, I. [Helmholtz-Zentrum Berlin for Materials and Energy, Albert-Einstein-Str. 15, D-12489 Berlin (Germany); Cordill, M.J. [Department Materials Physics, Montanuniversität Leoben, Jahnstrasse 12, 8700 Leoben (Austria); Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Jahnstrasse 12, 8700 Leoben (Austria)

    2014-02-03

    Substantial recovery (decrease) of electrical resistance during and after unloading is demonstrated for copper films on polyethylene terephthalate substrates subjected to a tensile strain with different peak values. Particularly, the films strained to 5% exhibit full resistance recovery after unloading despite clearly visible plastic deformation of the film. The recovery of electrical resistance in connection with the mechanical behavior of film/substrate couple is discussed with the help of in situ scanning electron microscopy and X-ray diffraction analysis. - Highlights: • Tensile tests on 200 nm Cu films on PET substrate are performed. • Electrical resistance is recorded in-situ during loading and unloading. • Significant recovery (decrease) of resistance is observed during and after unloading. • Films strained to 5% demonstrate full resistance recovery. • Viscoelastic relaxation of PET is responsible for recovery of Cu film resistance.

  14. Comparative toxicity and biodistribution of copper nanoparticles and cupric ions in rats

    Directory of Open Access Journals (Sweden)

    Lee IC

    2016-06-01

    Full Text Available In-Chul Lee,1 Je-Won Ko,1 Sung-Hyeuk Park,1 Je-Oh Lim,1 In-Sik Shin,1 Changjong Moon,1 Sung-Hwan Kim,2 Jeong-Doo Heo,3 Jong-Choon Kim1 1College of Veterinary Medicine BK21 Plus Project Team, Chonnam National University, Gwangju, 2Jeonbuk Department of Inhalation Research, Korea Institute of Toxicology, Jeongeup, 3Gyeongnam Department of Environment and Toxicology, Korea Institute of Toxicology, Gyeongnam, Republic of Korea Abstract: Despite widespread use and prospective biomedical applications of copper nanoparticles (Cu NPs, their biosafety issues and kinetics remain unclear. Thus, the aim of this study was to compare the detailed in vivo toxicity of Cu NPs and cupric ions (CuCl2; Cu ions after a single oral dose. We determined the physicochemical characteristics of Cu NPs, including morphology, hydrodynamic size, zeta potential, and dissolution in gastric (pH 1.5, vehicle (pH 6.5, and intestinal (pH 7.8 conditions. We also evaluated the kinetics of Cu following a single equivalent dose (500 mg/kg of Cu NPs and Cu ions. Cu NPs had highest dissolution (84.5% only in gastric conditions when compared with complete dissolution of Cu ions under various physiological milieus. Kinetic analysis revealed that highest Cu levels in blood and tested organs of Cu NP-treated rats were 15%–25% lower than that of Cu ions. Similar to the case of Cu ions, Cu levels in the tested organs (especially liver, kidney, and spleen of Cu NP-treated rats increased significantly when compared with the vehicle control. However, delay in reaching the highest level and biopersistence of Cu were observed in the blood and tested organs of Cu NP-treated rats compared with Cu ions. Extremely high levels of Cu in feces indicated that unabsorbed Cu NPs or absorbed Cu ions were predominantly eliminated through liver/feces. Cu NPs exerted apparent toxicological effects at higher dose levels compared with Cu ions and showed sex-dependent differences in mortality, biochemistry, and

  15. Extraction of copper(II) ions from aqueous solutions with a methimazole-based ionic liquid.

    Science.gov (United States)

    Reyna-González, Juan M; Torriero, Angel A J; Siriwardana, Amal I; Burgar, Iko M; Bond, Alan M

    2010-09-15

    The recently synthesized ionic liquid (IL) 2-butylthiolonium bis(trifluoromethanesulfonyl)amide, [mimSBu][NTf(2)], has been used for the extraction of copper(II) from aqueous solution. The pH of the aqueous phase decreases upon addition of [mimSBu](+), which is attributed to partial release of the hydrogen attached to the N(3) nitrogen atom of the imidazolium ring. The presence of sparingly soluble water in [mimSBu][NTf(2)] also is required in solvent extraction studies to promote the incorporation of Cu(II) into the [mimSBu][NTf(2)] ionic liquid phase. The labile copper(II) system formed by interacting with both the water and the IL cation component has been characterized by cyclic voltammetry as well as UV-vis, Raman, and (1)H, (13)C, and (15)N NMR spectroscopies. The extraction process does not require the addition of a complexing agent or pH control of the aqueous phase. [mimSBu][NTf(2)] can be recovered from the labile copper-water-IL interacting system by washing with a strong acid. High selectivity of copper(II) extraction is achieved relative to that of other divalent cobalt(II), iron(II), and nickel(II) transition-metal cations. The course of microextraction of Cu(2+) from aqueous media into the [mimSBu][NTf(2)] IL phase was monitored in situ by cyclic voltammetry using a well-defined process in which specific interaction with copper is believed to switch from the ionic liquid cation component, [mimSBu], to the [NTf(2)] anion during the course of electrochemical reduction from Cu(II) to Cu(I). The microextraction-voltammetry technique provides a fast and convenient method to determine whether an IL is able to extract electroactive metal ions from an aqueous solution.

  16. Separation of metalloproteins using a novel metal ion contaminant sweeping technique and detection of protein-bound copper by a metal ion probe in polyacrylamide gel electrophoresis: distribution of copper in human serum.

    Science.gov (United States)

    Saito, Shingo; Kawashima, Mitsuyoshi; Ohshima, Hiroki; Enomoto, Kazuki; Sato, Makoto; Yoshimura, Hajime; Yoshimoto, Keitaro; Maeda, Mizuo; Shibukawa, Masami

    2013-10-21

    A polyacrylamide gel electrophoresis (PAGE)-based method has been developed, consisting of two types of gel electrophoresis, to obtain an accurate distribution of protein-bound metal ions in biological samples. First, proteins are separated by PAGE without the uptake of contaminant metal ions in the separation field and dissociation of metal ions from the proteins. This is followed by another PAGE for the separation and detection of protein-bound metal ions in small volume samples with high sensitivity in the ppt range using a fluorescent metal probe. The former is a new technique using blue-native (BN) PAGE to electrophoretically sweep all metal contaminants by employing two kinds of chelating agents. These agents form complexes with contaminants in the gel and the separation buffer solution, which migrate towards opposite pole directions, thus lowering the contaminants to below the ppt level during separation. This is termed "Metal Ion Contaminant Sweeping BN-PAGE (MICS-BN-PAGE)". After the separation of proteins under these first metal-free conditions, the metal ions in the gel fractions are eluted, followed by derivatization of copper ions into the metal probe complexes to be separated and determined by fluorescence detection in the second PAGE. In this PAGE-based method, the copper ions bound to ceruloplasmin and superoxide dismutase were quantitatively determined, in addition to the exchangeable albumin-bound copper ions. This system successfully provided distribution maps of protein-copper in human serum. The precise distribution of copper in human serum was investigated, and found to be different from that which is widely accepted.

  17. The interfacial structure of plated copper alloy resistance spot welded joint

    Science.gov (United States)

    Wu, Jingwei; Zhai, Guofu; Chen, Qing; Wang, Jianqi; Ren, Gang

    2008-09-01

    Plated copper alloys are widely used in electron industry. The plating lay caused the farther decreasing of the welding property of copper alloys, whose intrinsic weldability was poor. In this paper, the bronze and brass specimens with nickel-tin double plating layer were joined by resistance spot welding method. The microstructure and peel strength of the joints were investigated. The experiment results show that a sandwich-like structure was obtained in the faying surface after welding, and the nickel plating layer thickness had severe effect on the reliability of the joints.

  18. The interfacial structure of plated copper alloy resistance spot welded joint

    Energy Technology Data Exchange (ETDEWEB)

    Wu Jingwei [Xiamen Hongfa Electroacoustic Co., Ltd, 361021 Xiamen (China); Harbin Institute of Technology, 150001 Harbin (China)], E-mail: jingweiwu.hit@gmail.com; Zhai Guofu [Harbin Institute of Technology, 150001 Harbin (China); Chen Qing; Wang Jianqi; Ren Gang [Xiamen Hongfa Electroacoustic Co., Ltd, 361021 Xiamen (China)

    2008-09-15

    Plated copper alloys are widely used in electron industry. The plating lay caused the farther decreasing of the welding property of copper alloys, whose intrinsic weldability was poor. In this paper, the bronze and brass specimens with nickel-tin double plating layer were joined by resistance spot welding method. The microstructure and peel strength of the joints were investigated. The experiment results show that a sandwich-like structure was obtained in the faying surface after welding, and the nickel plating layer thickness had severe effect on the reliability of the joints.

  19. MECHANICAL PROPERTIES OF PVA NANOFIBER TEXTILES WITH INCORPORATED NANODIAMONDS, COPPER AND SILVER IONS

    Directory of Open Access Journals (Sweden)

    Kateřina Indrová

    2015-02-01

    Full Text Available The unique properties of nanotextiles based on poly(vinyl-alcohol (PVA manufactured using electrospinning method have been known and exploited for many years. Recently, the enrichment of nanofiber textiles with nanoparticles, such as ions or nanodiamond particles (NDP, has become a popular way to modify the textile mechanical, chemical and physical properties. The aim of our study is to investigate the macromechanical properties of PVA nanotextiles enriched with NDP, silver (Ag and copper (Cu ions. The nanofiber textiles of a various surface weight were prepared from 16% PVA solution, while glyoxal and phosphoric acid were used as cross-linking agents. The copper and silver ions were diluted in aqueous solution and NDP were dispersed into the fibers by ultrasound homogenization. All but one set of samples were exposed to the temperature of 140 °C for 10 minutes. The samples without thermal stabilization exhibited significantly lower elastic stiffness and tensile strength. Moreover, the results of tensile testing indicate that the addition of dispersed nanoparticles has a minor effect on the mechanical properties of textiles and contributes rather to their reinforcement. On the other hand, the lack of thermal stabilization results in a poor interconnection of individual nanofiber layers and the non-stabilized textiles exhibit a lower elastic stiffness and reduced tensile strength.

  20. Comparative toxicity and biodistribution of copper nanoparticles and cupric ions in rats.

    Science.gov (United States)

    Lee, In-Chul; Ko, Je-Won; Park, Sung-Hyeuk; Lim, Je-Oh; Shin, In-Sik; Moon, Changjong; Kim, Sung-Hwan; Heo, Jeong-Doo; Kim, Jong-Choon

    2016-01-01

    Despite widespread use and prospective biomedical applications of copper nanoparticles (Cu NPs), their biosafety issues and kinetics remain unclear. Thus, the aim of this study was to compare the detailed in vivo toxicity of Cu NPs and cupric ions (CuCl2; Cu ions) after a single oral dose. We determined the physicochemical characteristics of Cu NPs, including morphology, hydrodynamic size, zeta potential, and dissolution in gastric (pH 1.5), vehicle (pH 6.5), and intestinal (pH 7.8) conditions. We also evaluated the kinetics of Cu following a single equivalent dose (500 mg/kg) of Cu NPs and Cu ions. Cu NPs had highest dissolution (84.5%) only in gastric conditions when compared with complete dissolution of Cu ions under various physiological milieus. Kinetic analysis revealed that highest Cu levels in blood and tested organs of Cu NP-treated rats were 15%-25% lower than that of Cu ions. Similar to the case of Cu ions, Cu levels in the tested organs (especially liver, kidney, and spleen) of Cu NP-treated rats increased significantly when compared with the vehicle control. However, delay in reaching the highest level and biopersistence of Cu were observed in the blood and tested organs of Cu NP-treated rats compared with Cu ions. Extremely high levels of Cu in feces indicated that unabsorbed Cu NPs or absorbed Cu ions were predominantly eliminated through liver/feces. Cu NPs exerted apparent toxicological effects at higher dose levels compared with Cu ions and showed sex-dependent differences in mortality, biochemistry, and histopathology. Liver, kidney, and spleen were the major organs affected by Cu NPs. Collectively, the toxicity and kinetics of Cu NPs are most likely influenced by the release of Cu dissociated from Cu NPs under physiological conditions.

  1. Effect of decomposition and organic residues on resistivity of copper films fabricated via low-temperature sintering of complex particle mixed dispersions.

    Science.gov (United States)

    Yong, Yingqiong; Nguyen, Mai Thanh; Tsukamoto, Hiroki; Matsubara, Masaki; Liao, Ying-Chih; Yonezawa, Tetsu

    2017-03-24

    Mixtures of a copper complex and copper fine particles as copper-based metal-organic decomposition (MOD) dispersions have been demonstrated to be effective for low-temperature sintering of conductive copper film. However, the copper particle size effect on decomposition process of the dispersion during heating and the effect of organic residues on the resistivity have not been studied. In this study, the decomposition process of dispersions containing mixtures of a copper complex and copper particles with various sizes was studied. The effect of organic residues on the resistivity was also studied using thermogravimetric analysis. In addition, the choice of copper salts in the copper complex was also discussed. In this work, a low-resistivity sintered copper film (7 × 10(-6) Ω·m) at a temperature as low as 100 °C was achieved without using any reductive gas.

  2. Transport Measurements in the Mixed Ion-Electron Conductor Copper(x) Carbon-Disulfide

    Science.gov (United States)

    Kuo, Hung-Jen

    (sigma)(,i), (sigma)(,e), and the chemical diffusion coefficient, (')D, of highly-disordered Cu(,x)CS(,2) were investigated using a dc 4-lead technique employing Pt electrodes. The experiments were performed at various copper concentrations from x = 2.87 to 3.60 and various temperatures from 260 K to 350 K. The results were interpreted by Yokota's and ionic hopping diffusion theories. (sigma)(,i) and (sigma)(,e) are comparable at room temperature, 4.18 x 10('-3) (OMEGA)('-1)cm('-1) and 1.55 x 10('-3) (OMEGA)('-1)cm('-1) respectively at X = 3.60 and 300 K. Both (sigma)(,i) and (sigma)(,e) follow a simple Arrhenius form with activation energies (TURN)0.40 eV and (TURN)0.29 eV respectively. The exponential dependence of (sigma)(,i) on X is explained in terms of the activation entropy associated with the motion of ions. Electronic conduction is by hopping. Results show that it is reasonable to assume that all the copper ions are mobile. The mobility and the diffusivity of copper ions were found to be 0.71 x 10('-6) cm('2)V(' -1)sec('-1) and 1.83 x 10('-8) cm('2)/sec respectively at X = 3.6 and 300 K. The diffusivity is much less than the chemical diffusion coefficient evaluated from the diffusion time constant, (')D = 0.829 x 10('-5) cm('2)/sec at X = 3.60 and 300 K. This is because of a large enhancement factor W (TURN) 453, or a large (PAR-DIFF)m(,e)/(PAR-DIFF)N. The change in galvanic cell potential E with X, -(PAR-DIFF)E/(PAR -DIFF)X, calculated from the measurements of (sigma)(,i), (sigma)(,e), and (')D, is 14 Volt.

  3. A novel zerovalent manganese for removal of copper ions: synthesis, characterization and adsorption studies

    Science.gov (United States)

    Dada, A. O.; Adekola, F. A.; Odebunmi, E. O.

    2015-11-01

    Synthesis of nanoscale zerovalent manganese (nZVMn) by chemical reduction was carried out in a single pot system under inert environment. nZVMn was characterized using a combination of analytical techniques: Ultraviolet-Visible Spectroscopy, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Transmission Electron Microscopy, Energy Dispersive X-ray, BET surface area and Point of Zero Charge. The adsorption physicochemical factors: pH, contact time, adsorbent dose, agitation speed, initial copper ion concentration and temperature were optimized. The kinetic data fitted better to Pseudo second-order, Elovich, fractional power and intraparticle diffusion models and their validity was tested by three statistical models: sum of square error, Chi-square (χ 2) and normalized standard deviation (Δq). Seven of the two-parameter isotherm models [Freundlich, Langmuir, Temkin, Dubinin-Kaganer-Raduskevich (DKR), Halsey, Harkin-Jura and Flory-Huggins] were used to analyse the equilibrium adsorption data. The Langmuir monolayer adsorption capacity (Q max = 181.818 mg/g) obtained is greater than other those of nano-adsorbents utilized in adsorption of copper ions. The equilibrium adsorption data were better described by Langmuir, Freundlich, Temkin, DKR and Halsey isotherm models considering their coefficient of regression (R 2 > 0.90). The values of the thermodynamic parameters: standard enthalpy change ∆H° (+50.27848 kJ mol-1), standard entropy change ∆S° (203.5724 J mol-1 K-1) and the Gibbs free energy change ∆G° revealed that the adsorption process was feasible, spontaneous, and endothermic in nature. The performance of this novel nanoscale zerovalent manganese (nZVMn) suggested that it has a great potential for effective removal of copper ions from aqueous solution.

  4. A novel zerovalent manganese for removal of copper ions: synthesis, characterization and adsorption studies

    Science.gov (United States)

    Dada, A. O.; Adekola, F. A.; Odebunmi, E. O.

    2017-06-01

    Synthesis of nanoscale zerovalent manganese (nZVMn) by chemical reduction was carried out in a single pot system under inert environment. nZVMn was characterized using a combination of analytical techniques: Ultraviolet-Visible Spectroscopy, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Transmission Electron Microscopy, Energy Dispersive X-ray, BET surface area and Point of Zero Charge. The adsorption physicochemical factors: pH, contact time, adsorbent dose, agitation speed, initial copper ion concentration and temperature were optimized. The kinetic data fitted better to Pseudo second-order, Elovich, fractional power and intraparticle diffusion models and their validity was tested by three statistical models: sum of square error, Chi-square ( χ 2) and normalized standard deviation (Δ q). Seven of the two-parameter isotherm models [Freundlich, Langmuir, Temkin, Dubinin-Kaganer-Raduskevich (DKR), Halsey, Harkin-Jura and Flory-Huggins] were used to analyse the equilibrium adsorption data. The Langmuir monolayer adsorption capacity ( Q max = 181.818 mg/g) obtained is greater than other those of nano-adsorbents utilized in adsorption of copper ions. The equilibrium adsorption data were better described by Langmuir, Freundlich, Temkin, DKR and Halsey isotherm models considering their coefficient of regression ( R 2 > 0.90). The values of the thermodynamic parameters: standard enthalpy change ∆ H° (+50.27848 kJ mol-1), standard entropy change ∆ S° (203.5724 J mol-1 K-1) and the Gibbs free energy change ∆ G° revealed that the adsorption process was feasible, spontaneous, and endothermic in nature. The performance of this novel nanoscale zerovalent manganese (nZVMn) suggested that it has a great potential for effective removal of copper ions from aqueous solution.

  5. Removal of Copper (II Ions from Aqueous Solutions by Adsorption with Low Cost Acid Activated Cynodon Dactylon Carbon

    Directory of Open Access Journals (Sweden)

    U. Gayathri

    2011-01-01

    Full Text Available The main purpose of this work was to exploit low cost and efficient sorbents for the removal of copper from aqueous solution using Cynodon dactylon carbon. It was observed from the experimental results that almost 90-100% copper can be removed from the aqueous solution. Adsorption kinetics and equilibrium have been investigated as a function of initial copper ion concentration. pH, contact time and adsorbent dosage. Kinetics studies suggested that the adsorption allowed first order reaction. Equilibrium data were analyzed using Langmuir and Freundlich isotherm models. On the basis of experimental results and the model parameters, it can be concluded that the carbonaceous Cynodon dactylon is effective for the removal of copper ion from aqueous solution.

  6. Characterization of copper resistant ciliates: Potential candidates for ...

    African Journals Online (AJOL)

    Jane

    2011-08-17

    Aug 17, 2011 ... tolerate, resist or detoxify organic substances and heavy metals (Shakoori et al., 2004). ...... hexavalent chromium from industrial waste water. Bull. Environ. ... chemistry, vol. 2, Part K: Biodegradation and persistence (ed. B.

  7. Rapid determination of trace level copper in tea infusion samples by solid contact ion selective electrode

    OpenAIRE

    2016-01-01

    A new solid contact copper selective electrode with a poly (vinyl chloride) (PVC) membrane consisting of o-xylylenebis(N,N-diisobutyldithiocarbamate) as ionophore has been prepared. The main novelties of constructed ion selective electrode concept are the enhanced robustness, cheapness, and fastness due to the use of solid contacts. The electrode exhibits a rapid (< 10 seconds) and near-Nernstian response to Cu2+ activity from 10−1 to 10−6 mol/L at the pH range of 4.0–6.0. No serious interfer...

  8. Silicon-Copper Helical Arrays for New Generation Lithium Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Polat, B. D.; Keles, O; Amine, K

    2015-09-22

    The helical array (with 10 atom % Cu) exhibits 3130 mAh g–1 with 83% columbic efficiency and retains 83% of its initial discharge capacity after 100th cycle. Homogeneously distributed interspaces between the helical arrays accommodate high volumetric changes upon cycling and copper atoms form a conductive network to buffer the mechanical stress generated in the electrode while minimizing electrochemical agglomeration of Si. Also, ion assistance is believed to enhance the density of the helices at the bottom thus increasing the adhesion

  9. Chromium Ions Improve Moisure Resistance of Epoxy Resins

    Science.gov (United States)

    St. Clair, A. K.; St. Clair, T. L.; Stoakley, D. M.; Singh, J. J.; Sprinkle, D. R.

    1986-01-01

    Broad spectrum of thermosetting epoxy resins used on commercial and military aircraft, primarily as composite matrices and adhesives. In new technique, chromium-ion containing epoxy with improved resistance to moisture produced where chromium ions believed to prevent absorption of water molecules by coordinating themselves to hydroxyl groups on epoxy chain. Anticipated that improved epoxy formulation useful as composite matrix resin, adhesive, or casting resin for applications on commercial and advanced aircraft. Improvement made without sacrifice in mechanical properties of polymer.

  10. Mathematical modeling of copper(II) ion inhibition on COD removal in an activated sludge unit.

    Science.gov (United States)

    Pamukoglu, M Yunus; Kargi, Fikret

    2007-07-19

    A mathematical model was developed to describe the Cu(II) ion inhibition on chemical oxygen demand (COD) removal from synthetic wastewater containing 15 mg l(-1) Cu(II) in an activated sludge unit. Experimental data obtained at different sludge ages (5-30 days) and hydraulic residence times (HRT) (5-25 h) were used to determine the kinetic, stoichiometric and inhibition constants for the COD removal rate in the presence and absence of Cu(II) ions. The inhibition pattern was identified as non-competitive, since Cu(II) ion inhibitions were observed both on maximum specific substrate removal rate (k) and on the saturation constant (Ks) with the inhibition constants of 97 and 18 mg l(-1), respectively, indicating more pronounced inhibition on Ks. The growth yield coefficient (Y) decreased and the death rate constant (b) increased in the presence of Cu(II) ions due to copper ion toxicity on microbial growth with inhibition constants of 29 and 200 mg l(-1), respectively indicating more effective inhibition on the growth yield coefficient or higher maintenance requirements. The mathematical model with the predetermined kinetic constants was able to predict the system performance reasonably well especially at high HRT operations.

  11. [Isolation and biodiversity of copper-resistant bacteria from rhizosphere soil of Elsholtzia splendens].

    Science.gov (United States)

    Sun, Leni; He, Linyan; Zhang, Yanfeng; Zhang, Wenhui; Wang, Qi; Sheng, Xiafang

    2009-10-01

    Isolation and characterization of rhizosphere copper-resistant bacteria from a copper accumulator plant Elsholtzia splendens were investigated. Cultivable Cu-resistant bacteria were isolated by plating and screening from rhizosphere soils of Elsholtzia splendens growing on a copper mine tailing. Bacteria were characterized regarding characteristics that may be relevant for a beneficial plant-microbe interaction--Cu tolerance, phosphate-solubilizing, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, siderophore and indoleacetic acid production, and further classified by restriction analysis of 16S rDNA (ARDRA). Strains that produced ACC deaminase were identified by 16S rDNA sequence analysis. Twenty-seven Cu-resistant strains were isolated from rhizosphere soil of Elsholtzia splendens and classified by ARDRA in 7 different taxonomic groups at the similarity level of 60% . All strains produced IAA or their derivatives, 44.4% of the strains produced a very high level of siderophores, and five strains were able to grow on ACC as the sole nitrogen source. Strains 2EBS12, 2EBS13, 2EBS15 and 3EBS11 were identified as Acinetobacter, strain 2EBS14 was essentially consistent Alcaligenes. Cu-resistant rhizobacteria isolated from Elsholtzia splendens have abundant characteristics relative to promoting plant growth and genetic diversity, rhizobacteria Acinetobacter sp. and Alcaligenes sp. contained ACC deaminase activity.

  12. Fabrication of Chitosan-complexed Electrode and Evaluation of Its Efficiency in Removal of Copper Ion from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Yoon Young-Chan

    2016-01-01

    Full Text Available In this study, we fabricated chitosan/PVA/activated carbon complexed electrode to remove copper ion from aqueous solution. The prepared composite electrode was analyzed by BET and SEM to investigate its physicochemical properties. Electrochemical properties of prepared composite electrodes were analyzed via cyclic voltammetry. Adsorption performance of copper ion on chitosan composite complexed electrodes was evaluated. Almost similar pore size distribution results were observed in the series of ACP not included electrodes while observed differences in pore size distribution for the ACP included one. Cyclic voltammetry results exhibited that oxidation-reduction reaction does not occur in a potential range of -1.0 ~ 1.0 V. The amount of copper ion during adsroption reaction is increase according to increase of adsorption potential to 1.0 V.

  13. EFFECTS OF COPPER ION IMPLANTATION ON ANTIBACTERIAL ACTIVITY OF AISI420 STAINLESS STEEL

    Institute of Scientific and Technical Information of China (English)

    Z.G. Dan; H.W. Ni; B.F. Xu; J. Xiong; P. Y. Xiong

    2005-01-01

    Antibacterial activity of AISI420 stainless steel (SS) implanted by copper was investigated. Ions extracted from a metal vapor vacuum arc (MEVVA) are sourced with 100keV energy and a dose range from 0.2×1017 to 2.0×1017ions .cm-2. The saturation dose of Cu implantation in AISI420 SS and Cu surface concentration were calculated at the energy of 100keV. The effect of dose on the antibacterial activity was analyzed. Results of antibacterial test show that the saturation dose is the optimum implantation dose for best antibacterial activity, which is above 99% against both Escherichia coli and Staphylococcus aureus. Novel phases such as Fe4Cu3 and Cu9.9Fe0.1 were found in the implanted layer by glancing angle X-ray diffraction (GXRD). The antibacterial activity of AISI420 SS attributes to Cu-contained phase.

  14. Corrosion resistance of monolayer hexagonal boron nitride on copper

    Science.gov (United States)

    Mahvash, F.; Eissa, S.; Bordjiba, T.; Tavares, A. C.; Szkopek, T.; Siaj, M.

    2017-02-01

    Hexagonal boron nitride (hBN) is a layered material with high thermal and chemical stability ideal for ultrathin corrosion resistant coatings. Here, we report the corrosion resistance of Cu with hBN grown by chemical vapor deposition (CVD). Cyclic voltammetry measurements reveal that hBN layers inhibit Cu corrosion and oxygen reduction. We find that CVD grown hBN reduces the Cu corrosion rate by one order of magnitude compared to bare Cu, suggesting that this ultrathin layer can be employed as an atomically thin corrosion-inhibition coating.

  15. Colorimetric and fluorimetric response of salicylaldehyde dithiosemicarbazone towards fluoride, cyanide and copper ions: Spectroscopic and TD-DFT studies

    Science.gov (United States)

    Harikrishnan, Vengayil K.; Basheer, Sabeel M.; Joseph, Nithin; Sreekanth, Anandaram

    2017-07-01

    The sensing mechanism of salicylaldehyde phenyldithiosemicarbazone (SDTSC) chemosensor has been investigated by spectroscopic and TD-DFT methods. The SDTSC shows colourimetric and spectral changes towards fluoride, cyanide and copper ions. The interaction between SDTSC with fluoride, cyanide and copper ions was examined through their absorption and fluorescence behaviour, and found that SDTSC has more sensing ability towards Cu2 + ion than CN- and F- ions. The 1H NMR titration with SDTSC and F- gives the structural changes in the sensing process. The reversibility of SDTSC was also evaluated and thus it is confirmed as a reusable chemosensor which can be clarified by the ;Read-Erase-Read-Write; logic system. The DFT and TD-DFT calculations give the detailed sensing mechanism of SDTSC towards fluoride ion. The potential energy surface (PES) analysis confirms the excited state electron transfer mechanism.

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

    Science.gov (United States)

    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 MoS2, for further explorations.

  17. Real-time monitoring of copper ions-induced cytotoxicity by EIS cell chips.

    Science.gov (United States)

    Primiceri, Elisabetta; Chiriacò, Maria Serena; D'Amone, Eliana; Urso, Emanuela; Ionescu, Rodica Elena; Rizzello, Antonia; Maffia, Michele; Cingolani, Roberto; Rinaldi, Ross; Maruccio, Giuseppe

    2010-08-15

    An important goal of biomedical research is the development of tools for high-throughput evaluation of drug effects and cytotoxicity tests. Here we demonstrate EIS cell chips able to monitor cell growth, morphology, adhesion and their changes as a consequence of treatment with drugs or toxic compounds. As a case study, we investigate the uptake of copper ions and its effect on two cell lines: B104 and HeLa cells. For further understanding, we also carried out in parallel with EIS studies, a complete characterization of cell morphology and changes induced by copper ions through complementary methodologies (including state-of-the-art AFM, viability test and Western blot). Our results reveal a strong correlation between EIS data and both MTT test and AFM characterization so our chip can be used as powerful tools in all biology lab in combination with other standard methods giving additional information that can be useful in a complete and deep investigation of a biological process. This chip can be used even alone replacing in vitro drug tests based on conventional biochemical methods, being very cheap and reusable and allowing to perform cytotoxicity tests without using any expensive reagent or equipment.

  18. Complete Genome Sequence of Xanthomonas arboricola pv. juglandis 417, a Copper-Resistant Strain Isolated from Juglans regia L.

    Science.gov (United States)

    Pereira, Ulisses P; Gouran, Hossein; Nascimento, Rafael; Adaskaveg, James E; Goulart, Luiz Ricardo; Dandekar, Abhaya M

    2015-01-01

    Here, we report the complete genome sequence of Xanthomonas arboricola pv. juglandis 417, a copper-resistant strain isolated from a blighted walnut fruit (Juglans regia L. cv. Chandler). The genome consists of a single chromosome (5,218 kb).

  19. Copper resistance of different ectomycorrhizal fungi such as Pisolithus microcarpus, Pisolithus sp., Scleroderma sp. and Suillus sp.

    Directory of Open Access Journals (Sweden)

    R.F. Silva

    2013-01-01

    Full Text Available Environments contaminated with heavy metals negatively impact the living organisms. Ectomycorrhizal fungi have shown important role in these impacted sites. Thus, this study aimed to evaluate the copper-resistance of ectomycorrhizal fungi isolates Pisolithus microcarpus - UFSC-Pt116; Pisolithus sp. - UFSC-PT24, Suillus sp. - UFSM RA 2.8 and Scleroderma sp. - UFSC-Sc124 to different copper doses in solid and liquid media. The copper doses tested were: 0.00, 0.25, 0.5, 0.75, 1.0 and 1.25 mmol L-1 in the solid medium and 0.00, 0.32, 0.64 and 0.96 mmol L-1 in the liquid medium. Copper was amended as copper sulphate in order to supplement the culture medium MNM at pH 4.8, with seven replicates to each fungus-dose combination. The fungal isolates were incubated for 30 days at 28 °C. UFSC-Pt116 showed high copper-resistance such as accessed by CL50 determinations (concentration to reduce 50% of the growth as while as UFSC-PT24 displayed copper-resistance mechanism at 0.50 mmol L-1 in solid medium. The UFSC-PT24 and UFSC-Sc124 isolates have increased copper-resistance in liquid medium. The higher production of extracellular pigment was detected in UFSC-Pt116 cultures. The UFSC-Pt116 and UFSC-PT24 isolates showed higher resistance for copper and produced higher mycelium biomass than the other isolates. In this way, the isolates UFSG-Pt116 and UFSC-PT24 can be important candidates to survive in copper-contaminated areas, and can show important role in plants symbiosis in these contaminated sites.

  20. Effect of Contact Pressure on the Resistance Contact Value and Temperature Changes in Copper Busbar Connection

    Directory of Open Access Journals (Sweden)

    Agus Risdiyanto

    2012-12-01

    Full Text Available This paper discussed the influence of tightness or contacts pressure on copper busbar joints to determine changes in the value of the initial contact resistance and the maximum temperature at the joint due to high current load. The test sample was copper busbar 3 x 30 mm with configuration of bolted overlapping joint. Increasing contact pressure at the joint was measured to find out its effect on the value of contact resistance. The applied pressure was 6 to 36 MPa. Procedure of contact resistance measurement refer to the ASTM B539 standard using four-wire method. The sample subsequently loaded with the current of 350 A for 60 minutes and the maximum temperature at the joint was measured. The result showed that increasing contact pressure at the busbar joint will reduce the contact resistance and maximum temperature. The increase of contact pressure from 6 to 30 MPa causes decreasing contact resistance from 16 μΩ to 11 μΩ. Further increasing of contact pressure more than 30 MPa did not affect the contact resistance significantly. The lowest temperatur of busbar joint of 54°C was reached at a contact pressure of 36 Mpa.

  1. The corrosion rate of copper in a bentonite test package measured with electric resistance sensors

    Energy Technology Data Exchange (ETDEWEB)

    Rosborg, Bo [Division of Surface and Corrosion Science, KTH, Stockholm (Sweden); Kosec, Tadeja; Kranjc, Andrej; Kuhar, Viljem; Legat, Andraz [Slovenian National Building and Civil Engineering Institute, Ljubljana (Slovenia)

    2012-12-15

    LOT1 test parcel A2 was exposed for six years in the Aespoe Hard Rock Laboratory, which offers a realistic environment for the conditions that will prevail in a deep repository for high-level radioactive waste disposal in Sweden. The test parcel contained copper electrodes for real-time corrosion monitoring in bentonite ring 36, where the temperature was 24 deg C, and copper coupons in bentonite rings 22 and 30, where the temperature was higher. After retrieval of the test parcel in January 2006, a bentonite test package consisting of bentonite rings 35 - 37 was placed in a container and sealed with a thick layer of paraffin. Later the same year new copper electrodes were installed in the test package. In January 2007 electric resistance (ER) sensors of pure copper with a thickness of 35 {mu}m were also installed in the test package mainly to facilitate the interpretation of the results from the real-time corrosion monitoring with electrochemical techniques. The ER measurements have shown that the corrosion rate of pure copper exposed in an oxic bentonite/ saline groundwater environment at room temperate decreases slowly with time to low but measurable values. The corrosion rates estimated from the regularly performed EIS measurements replicate the ER data. Thus, for this oxic environment in which copper acquires corrosion potentials of the order of 200 mV (SHE) or higher, electrochemical measurements provide believable data. Comparing the recorded ER data with an estimate of the average corrosion rate based on comparing cross-sections from exposed and protected sensor elements, it is obvious that the former overestimates the actual corrosion rate, which is understandable. It seems as if electrochemical measurements can provide a better estimate of the corrosion rate; however, this is quite dependent on the use of proper measuring frequencies and evaluation methods. In this respect ER measurements are more reliable. It has been shown that real-time corrosion

  2. Estimation of free copper ion concentrations in blood serum using T1 relaxation rates

    Science.gov (United States)

    Blicharska, Barbara; Witek, Magdalena; Fornal, Maria; MacKay, Alex L.

    2008-09-01

    The water proton relaxation rate constant R1 = 1/ T1 (at 60 MHz) of blood serum is substantially increased by the presence of free Cu 2+ ions at concentrations above normal physiological levels. Addition of chelating agents to serum containing paramagnetic Cu 2+ nulls this effect. This was demonstrated by looking at the effect of adding a chelating agent—D-penicillamine (D-PEN) to CuSO 4 and CuCl 2 aqueous solutions as well as to rabbit blood serum. We propose that the measurement of water proton spin-lattice relaxation rate constants before and after chelation may be used as an alternative approach for monitoring the presence of free copper ions in blood serum. This method may be used in the diagnosis of some diseases (leukaemia, liver diseases and particularly Wilson's disease) because, in contrast to conventional methods like spectrophotometry which records the total number of both bound and free ions, the proton relaxation technique is sensitive solely to free paramagnetic ions dissolved in blood serum. The change in R1 upon chelation was found to be less than 0.06 s -1 for serum from healthy subjects but greater than 0.06 s -1 for serum from untreated Wilson's patients.

  3. PERIODATE AND HYPOBROMITE MODIFICATION OF SOUTHERN PINE WOOD TO IMPROVE SORPTION OF COPPER ION

    Directory of Open Access Journals (Sweden)

    James D. McSweeny

    2008-02-01

    Full Text Available Milled southern pine wood was modified with sequential treatments of sodium periodate and sodium hypobromite for the purpose of improving copper ion (Cu2+ sorption capacity of the wood when tested in 24-h equilibrium batch tests. The modified wood provided additional carboxyl groups to those in the native wood and substantially increased Cu2+ uptake over that of unmodified wood. Sorption capacity (qe measured with an unbuffered standard solution increased to a maximum of 7.8 mg Cu2+ ion per gram of wood (treated from 3.1 mg Cu2+ ion/g wood (untreated. Samples tested were first sodium ion exchanged to keep the pH of the standard solution from declining during the sorption test. The treatment necessary for maximum qe was 3% (w/v periodate for 24 h and 0.8% (w/v bromine (as hypobromite for 24 h; both treatments were at room temperature. These conditions corresponded to the maximum periodate concentration and treatment times tested. To further evaluate the efficacy of modification treatments, weight change after each treatment was determined. Weight loss after the periodate stage for any concentration and time used was minor, indicating the selective nature of this reaction. However, most of the weight loss was incurred after hypobromite treatment. Weight loss corresponding to the greatest increase in sorption capacity was 12.6% total from the combined periodate and hypobromite stages. The increase of carboxylate functional groups in the wood was monitored using FTIR/ATR spectroscopy.

  4. Activation of oxygen-mediating pathway using copper ions: fine-tuning of growth kinetics in gold nanorod overgrowth.

    Science.gov (United States)

    Liu, Wenqi; Zhang, Hui; Wen, Tao; Yan, Jiao; Hou, Shuai; Shi, Xiaowei; Hu, Zhijian; Ji, Yinglu; Wu, Xiaochun

    2014-10-21

    Growth kinetics plays an important role in the shape control of nanocrystals (NCs). Herein, we presented a unique way to fine-tune the growth kinetics via oxidative etching activated by copper ions. For the overgrowth of gold nanorods (Au NRs), competitive adsorption of dissolved oxygen on rod surface was found to slow down the overgrowth rate. Copper ions were able to remove the adsorbed oxygen species from the Au surface via oxidative etching, thus exposing more reaction sites for Au deposition. In this way, copper ions facilitated the overgrowth process. Furthermore, Cu(2+) rather than Cu(+) acted as the catalyst for the oxidative etching. Comparative study with Ag(+) indicated that Cu(2+) cannot regulate NC shapes via an underpotential deposition mechanism. In contrast, Ag(+) led to the formation of Au tetrahexahedra (THH) and a slight decrease of the growth rate at similar growth conditions. Combining the distinct roles of the two ions enabled elongated THH to be produced. Copper ions activating the O2 pathway suggested that dissolved oxygen has a strong affinity for the Au surface. Moreover, the results of NC-sensitized singlet oxygen ((1)O2) indicated that the absorbed oxygen species on the surface of Au NCs bounded with low-index facets mainly existed in the form of molecular O2.

  5. Isolation of copper oxide (CuO) nanoparticles resistant Pseudomonas strains from soil and investigation on possible mechanism for resistance.

    Science.gov (United States)

    Soltani Nezhad, Shahla; Rabbani Khorasgani, Mohammad; Emtiazi, Giti; Yaghoobi, Mohammad Mehdi; Shakeri, Shahryar

    2014-03-01

    The present study deals with isolation and characterization of copper oxide nanoparticles resistant Pseudomonas strains that were isolated from the soil collected from mining and refining sites of Sarcheshmeh copper mine in the Kerman Province of Iran. The three isolates were selected based on high level of copper oxide nanoparticles (CuO NPs) resistance. The isolates were authentically identified as Pseudomonas fluorescens CuO-1, Pseudomonas fluorescens CuO-2 and Pseudomonas sp. CuO-3 by morphological, biochemical and 16S rDNA gene sequencing analysis. The growth pattern of these isolates with all the studied CuO NPs concentrations was similar to that of control (without CuO NPs) indicating that CuO NPs would not affect the growth of isolated strains. A reduction in the amount of exopolysaccharides was observed after CuO NPs-P. fluorescens CuO-1 culture supernatant interaction. The Fourier transform infrared spectroscopy (FT-IR) peaks for the exopolysaccharides extracted from the bacterial culture supernatant and the interacted CuO NPs were almost similar. The exopolysaccharide capping of the CuO NPs was confirmed by FT-IR and X-ray diffraction analysis. The study of bacterial exopolysaccharides capped CuO NPs with E. coli PTCC 1338 and S. aureus PTCC 1113 showed less toxicity compared to uncoated CuO NPs. Our study suggests that the capping of nanoparticles by bacterially produced exopolysaccharides serve as the probable mechanism of tolerance.

  6. The Study of Corrosion and Wear Resistance of Copper Composite Coatings with Inclusions of Carbon Nanomaterials in the Copper Metal Matrix

    Directory of Open Access Journals (Sweden)

    Viktorija MEDELIENĖ

    2011-07-01

    Full Text Available This paper deals with the peculiarities of the behaviour of copper nanocomposite coatings with CNMs inclusions under the free corrosion conditions in the acidic medium. The parameters of corrosion current density (jcorr, anodic dissolution current density (ia and polarization resistance (Rp have been determined. In the acidic medium a stronger oxidation of nanostructured copper nanocomposites occurred. With longer immersion periods more corrosion products are formed, resulting in a increase in the polarization resistance (Rp of corrosion. Corrosion products cover the whole surface of the coatings and the corrosion rate (jcorr tends towards a steady value of 1.7×10-3 ¸ 2.1×10-3 A·cm-2 for all copper coatings studied: 1.7×10-3 A·cm-2 for both Cu and Cu-CNM1, 1.9×10-3 A·cm-2 - for Cu-CNM2 and 2.1×10-3 A·cm-2 - for Cu-CNM3 composite coatings. It has been established that nanocomposites possess a higher wear resistance as compared to that of pure copper. The damage of metal characterized as a depth scar (đ is lower. The roughness of the composites studied was found to be the essential factor affecting their wear resistance. Therefore, the wear resistance of nanocomposites is impaired when they are deposited on a hard steel substrate.http://dx.doi.org/10.5755/j01.ms.17.2.481

  7. The Study of Corrosion and Wear Resistance of Copper Composite Coatings with Inclusions of Carbon Nanomaterials in the Copper Metal Matrix

    Directory of Open Access Journals (Sweden)

    Viktorija MEDELIENĖ

    2011-07-01

    Full Text Available This paper deals with the peculiarities of the behaviour of copper nanocomposite coatings with CNMs inclusions under the free corrosion conditions in the acidic medium. The parameters of corrosion current density (jcorr, anodic dissolution current density (ia and polarization resistance (Rp have been determined. In the acidic medium a stronger oxidation of nanostructured copper nanocomposites occurred. With longer immersion periods more corrosion products are formed, resulting in a increase in the polarization resistance (Rp of corrosion. Corrosion products cover the whole surface of the coatings and the corrosion rate (jcorr tends towards a steady value of 1.7×10-3 ¸ 2.1×10-3 A·cm-2 for all copper coatings studied: 1.7×10-3 A·cm-2 for both Cu and Cu-CNM1, 1.9×10-3 A·cm-2 - for Cu-CNM2 and 2.1×10-3 A·cm-2 - for Cu-CNM3 composite coatings. It has been established that nanocomposites possess a higher wear resistance as compared to that of pure copper. The damage of metal characterized as a depth scar (đ is lower. The roughness of the composites studied was found to be the essential factor affecting their wear resistance. Therefore, the wear resistance of nanocomposites is impaired when they are deposited on a hard steel substrate.http://dx.doi.org/10.5755/j01.ms.17.2.481

  8. In-situ contact electrical resistance technique for investigating corrosion inhibitor adsorption on copper electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Moretti, G.; Quartarone, G.; Zingales, A. [Univ. of Venice (Italy). Dept. of Chemistry; Molokanov, V.V. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Physical Chemistry

    1998-02-01

    Traditional electrochemical tests and the contact electrical resistance technique (CER) were used to investigate the effect on corrosion of pure copper (99.999 wt%) of adding benzotriazole (BTA) and 1-hydroxybenzotriazone (1-OH-BTA) to acidic solutions (sulfuric acid [H{sub 2}SO{sub 4}], pH = 1.7, and sodium sulfate [Na{sub 2}SO{sub 4}] until total sulfate [SO{sub 4}{sup 2{minus}}] concentration = 0.1 M). This technique permitted growth of oxide and/or salt films as well as adsorption of the organic inhibitors on the copper surface to be evaluated. Formation of copper oxide ([Cu{sub 2}O]{sub 2})., sulfate (CuSo{sub 4}{center_dot}5H{sub 2}O), thiocyanate (CuSCN), and halogenyde (CuI, CuBr, and CuCl) films on copper electrodes was followed in situ in sulfate solutions at various pH values under low overpotentials. Effects of pH, solution anion content, and/or the amount of BTA or 1-OH-BTA on electrical resistance (R) of the surface films formed on pure copper electrodes were treated. BTA acted as a more efficient corrosion inhibitor than 1-OH-BTA, reaching inhibition percentages (IP) of {approximately}90% compared to those of 1-OH-BTA, which reached a maximum of {approximately}76% in 2 {times} 10{sup {minus}3} M solutions. It was possible to distinguish between maximum R of the surface film, found in solutions containing BTA, associated with the adsorption of neutral inhibitor molecules, and the sharp rise in R attributable to [Cu(BTA)]{sub n} complex formation.

  9. Effect of Lead and Copper on the Growth of Heavy Metal Resistance Fungi Isolated from Second Industrial City in Riyadh, Saudi Arabia

    Science.gov (United States)

    Siham, Al-Kadeeb A.

    In this study, soil samples for isolation of heavy metal resistance fungi were collected from different distance of Electric Meter manufactory in Second Industrial City, Riyadh, Saudi Arabia. Soil samples were analyzed chemically for heavy metal concentrations, total soluble salts and pH and mechanically for composition of soils. Saturation percent were determined also. Eighteen fungal isolates were grown in 10 mM concentration of either lead or copper ions. Aspergillus was predominant and represented by 6 species. Fusarium was represented by 4 species. Mucor was represented by 3 species. Penicillium was represented by 2 species. While Alternaria, Cephaliophora, Eurotium were represented by one species each. The intraspecific variability in growth response to Pb2+ and Cu2+ on agar and liquid culture was studied among isolated fungi. The growth rate of some fungi isolated on solid media was less sensitive to addition of lead or copper than biomass production in liquid culture.

  10. Study of the surface resistance of niobium sputter-coated copper cavities

    CERN Document Server

    Benvenuti, Cristoforo; Campisi, I E; Darriulat, Pierre; Peck, M A; Russo, R; Valente, A M

    1999-01-01

    A systematic study of the superconducting properties of niobium films deposited on the inner wall of copper radiofrequency cavities is presented. Films are grown by sputtering with different discharge gases (Xe, Kr, Ar and Ar/Ne mixtures) on substrates prepared under different conditions. The measured quantities include the surface resistance at 1.5 GHz, the critical temperature and the penetration depth. The surface resistance is analyzed in terms of its dependence on temperature, RF field and the density of trapped fluxons. Once allowance for electron scattering is made by means of a single mean free path parameter, good agreement with BCS theory is observed. The residual resistance is observed to be essentially noncorrelated with the superconducting properties, although influenced by specific coating conditions. On occasions, very low residual resistances, in the nano-ohm range, have been maintained over a broad range of RF field, indicating the absence of fundamental limitations specific to the film techn...

  11. RF surface resistance of copper-on-beryllium at cryogenic temperatures measured by a 22-GHZ demountable cavity

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jianfei; Krawczyk, F. L. (Frank L.); Kurennoy, S. (Sergey); Schrage, D. L. (Dale L.); Shapiro, A. H. (Alan H.); Tajima, T. (Tsuyoshi); Wood R. L. (Richard L.)

    2003-01-01

    A 22-GHz demountable cavity on the cold head of a compact refrigerator system was used to measure the RF performance of several coppt:r-plated Beryllium samples. The cavity inner surfce was treated by chemical polishing and heat treatment., as well as an OFE copper coupon to provide a baseline for comparison. The measured surhce resistance was reasonable and repeatable during either cooling or warming. Materials tested included four grades of Beryllium, OFE copper, alumina-dispersion strengthened copper (Glidcop), and Cu-plated versions of all of the above. Two coupons, Cuplated on Beryllium 0-30 and 1-70, offered comparable surface resistance to pure OFE copper or Cu-plated Glidcop. The RF surface resistance of Cu-on-Beryllium samples at cryogenic temperatures is reported together with that of other reference materials.

  12. Study of coagulation processes of selected humic acids under copper ions influence*

    Science.gov (United States)

    Boguta, Patrycja; Sokolowska, Zofia

    2013-04-01

    Humic acids have limited sorption capacity and big dose of metal or other mineral component which can be sorbed on humic acids, can cause saturation of negative, surface charge of humic acids leading to destabilization of dissolved humic acids compounds. Destabilisation can be observed as coagulation and floculation proces of humic acids. However there are a lot of mechanisms which causing precipitation of humic acids. Thereby, in order to full description of coagulation process, different methods should be applied. Ordinarily, humic acids coagulation is studied by measurement of absorbance, transmittance or carbon loss in solution. Meanwhile, very significant information is also variation of metal content in soil solution and information whether metal goes to precipitate together with humic acids or stays in dissolved form in solution. So, that, from one side, processes of stronger accumulation of metal can lead to soil degradation and micronutrient deficiency for plants. However, there is also possibility to stay metal in solution in toxic and bioavailable form for plants. Main aim of this paper was to study coagulation process of different humic acids extracted from mucking peats under copper ions influence at adjusted pH to 5. In order to this, four peaty-muck soils were taken from selected places in east part of Poland (meadows and river valleys). These soils differed by humification degree, secondary transformation, density and pH. At next step, humic acids were extracted from soils using sodium hydroxide (NaOH) extractant. After exact purification by washing with HF-HCl mixture and water, humic acids were liofilized. Solutions of humic acids were prepared at concentration 40 mg/dm3 with addition of different amount of copper ions to obtain final concentration of Cu(II) ranged from 0-40mg/dm3. After 24 hours solutions were investigated using measurements of absorbance at 470nm (UV-VIS spectrometer Jasco V-530), measurements of organic carbon in solution

  13. Biosorption of Lead and Copper by Heavy Metal Resistance Bacterium using Fourier Transform Infrared Spectrophotometer (FT IR

    Directory of Open Access Journals (Sweden)

    This paper should be cited as: Mohseni M, Khosravi F, Mohadjerani M, Chaichi, MJ . [ Biosorption of Lead and Copper by Heavy Metal Resistance Bacterium using Fourier Transform Infrared Spectrophotometer (FT - IR ]. MLJ. 201 4 ; 8 ( 3 : [Article in Persian] Mohseni, M. (PhD

    2014-09-01

    Full Text Available Background and Objectives: Contamination of environment to lead and copper is rising due to human activities. One of the best methods to remove heavy metals from the environment is bacterial remediation. This study aimed to isolate bacteria and investigate the mechanism of lead and copper bioremediation. Material and Methods: Heavy metal resistant bacteria were isolated from contaminated wastewater samples. The isolates with high resistance to lead and copper were selected for further studies and bioremediation was assessed by atomic absorption spectrophotometer. To determine the functional groups to remove metals, FT-IR was employed. In addition, plasmid curing was studied to determine the location of the genes that are resistance to heavy metals. Results: Ten bacterial isolates that are resistance to heavy metals were isolated. Among these, MKH3 with the highest remediation activity removed %90 lead and %92 copper from the growth medium. The absorption mechanism of MKH3 indicated that the functional groups such as carboxyl, amide, carbonyl and hydroxyl were most effective for removal of heavy metals from the growth medium. The results revealed that heavy metal resistant genes may be located on plasmid DNA. Furthermore, molecular identification demonstrated that MKH3 was similar to Enterobacterhormaechei with 98% homology. Conclusion: Bacterium isolated from a contaminated site showed the ability to remove a high amount of lead and copper. Thus, MKH3 could be useful for the bioremediation of heavy metals, particularly lead and copper, from industrial wastewater and contaminated sites.

  14. Controlled growth of few-layer hexagonal boron nitride on copper foils using ion beam sputtering deposition.

    Science.gov (United States)

    Wang, Haolin; Zhang, Xingwang; Meng, Junhua; Yin, Zhigang; Liu, Xin; Zhao, Yajuan; Zhang, Liuqi

    2015-04-01

    Ion beam sputtering deposition (IBSD) is used to synthesize high quality few-layer hexagonal boron nitride (h-BN) on copper foils. Compared to the conventional chemical vapor deposition, the IBSD technique avoids the use of unconventional precursors and is much easier to control, which should be very useful for the large-scale production of h-BN in the future.

  15. Possible wave formation and martensitic transformation of iron particles in copper single crystals during argon ion bombardment

    DEFF Research Database (Denmark)

    Thölén, Anders Ragnar; Li, Chang-Hai; Easterling, K.E.

    1983-01-01

    Thin single crystal copper specimens (thickness ~250 nm) containing coherent iron particles (diameter 40–50 nm) have been bombarded with argon ions (5, 80, and 330 keV). During this process some of the iron particles transform to martensite. The transformation was observed near the exposed surface...

  16. Electron Paramagnetic Resonance and Optical Absorption Studies on Copper Ions in Mixed Alkali Cadmium Phosphate Glasses

    Institute of Scientific and Technical Information of China (English)

    G.Giridhar; M.Rangacharyulu; R.V.S.S.N.Ravikumar; P.Sambasiva Rao

    2009-01-01

    Electron paramagnetic resonance (EPR) and optical absorption studies were carried out at room temperature on copper doped mixed alkali cadmium phosphate (LiNaCdP) glasses to understand the nature and symmetry of dopant. Three samples with varying concentrations of alkali ions have been prepared. The spin Hamiltonian parameters obtained from room temperature EPR spectra are: g||=2.437, g⊥=2.096, A||=117×10-4 cm-1, A⊥=26×10-4 cm-1 for LiNaCdP1, g||=2.441, g⊥=2.088, A||=121×10-4 cm-1, A⊥=25×10-4 cm-1 for LiNaCdP2 and g||=2.433, g⊥=2.096, A||=125×10-4 cm-1, A⊥=32×10-4 cm-1 for LiNaCdP3. These EPR results indicate that the dopant Cu2+ ion enters the glass matrix into a tetragonally elongated octahedral site. The bonding parameters evaluated by correlating optical and EPR data suggest that bonding between the central metal ion and ligands is partially covalent. The mixed alkali effect in cadmium phosphate glasses was reported.

  17. DNA cleavage system of nanosized graphene oxide sheets and copper ions.

    Science.gov (United States)

    Ren, Hongliu; Wang, Chong; Zhang, Jiali; Zhou, Xuejiao; Xu, Dafeng; Zheng, Jing; Guo, Shouwu; Zhang, Jingyan

    2010-12-28

    The exploration of efficient DNA intercalative agents (intercalators) is essential for understanding DNA scission, repair, and signal transduction. In this work, we explored systematically the graphene oxide (GO) interaction with DNA molecules using fluorescence spectroscopic (FL) and circular dichroism (CD) studies, gel electrophoresis, and DNA thermal denaturation. We demonstrated that the GO nanosheets could intercalate efficiently into DNA molecules. Significantly, we illustrated that the scission of DNA by GO sheets combining with copper ions could take place pronouncedly. The scission of DNA by the GO/Cu(2+) system is critically dependent on the concentrations of GO and Cu(2+) and their ratio. DNA cleavage ability exhibited by the GO with several other metal ions and the fact that GO/Cu(2+)-cleaved DNA fragments can be partially relegated suggest that the mechanism of DNA cleavage by the GO/metal ion system is oxidative and hydrolytic. The result reveals that the GO/Cu(2+) could be used as a DNA cleaving system that should find many practical applications in biotechnology and as therapeutic agents.

  18. D-penicillamine-templated copper nanoparticles via ascorbic acid reduction as a mercury ion sensor.

    Science.gov (United States)

    Lin, Shu Min; Geng, Shuo; Li, Na; Li, Nian Bing; Luo, Hong Qun

    2016-05-01

    Mercury ion is one of the most hazardous metal pollutants that can cause deleterious effects on human health and the environment even at low concentrations. It is necessary to develop new mercury detection methods with high sensitivity, specificity and rapidity. In this study, a novel and green strategy for synthesizing D-penicillamine-capped copper nanoparticles (DPA-CuNPs) was successfully established by a chemical reduction method, in which D-penicillamine and ascorbic acid were used as stabilizing agent and reducing agent, respectively. The as-prepared DPA-CuNPs showed strong red fluorescence and had a large Stoke's shift (270nm). Scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, fluorescence spectroscopy, and ultraviolet-visible spectrophotometry were utilized to elucidate the possible fluorescence mechanism, which could be aggregation-induced emission effect. Based on the phenomenon that trace mercury ion can disperse the aggregated DPA-CuNPs, resulting in great fluorescence quench of the system, a sensitive and selective assay for mercury ion in aqueous solution with the DPA-CuNPs was developed. Under optimum conditions, this assay can be applied to the quantification of Hg(2+) in the 1.0-30μM concentration range and the detection limit (3σ/slope) is 32nM. The method was successfully applied to determine Hg(2+) in real water samples.

  19. Effect of halide ions on passivation and pitting corrosion of copper in alkaline solutions

    Energy Technology Data Exchange (ETDEWEB)

    Gad Allah, A.G.; Abou-Romia, M.M.; Badawy, W.A.; Rehan, H.H. (Cairo Univ., Gizeh (Egypt). Dept. of Chemistry)

    1991-11-01

    The passivity of copper in NaOH and borate buffer solutions containing chloride, bromide and fluoride ions was studied by using cyclic voltammetry and potentiostatic current transient measurements. At scan rates >> 20 mVs{sup -1}, the addition of halide ions does not nearly affect the cyclic voltammograms in the absence of pitting. But they differ considerably in presence of pitting. The pitting potential was found to depend on the solution pH and decreased linearly with increase of logarithm of halide ion concentration. The current transients in the passivity as well as in the pitting potential regions were analyzed. Before the pitting, i-time curves were rather similar to those obtained in the plain solutions. At times > 20 seconds, the current varies linearly with the reciprocal of the square root of time indicating diffusional characteristics of the metal corrosion through the passive layer. In presence of pitting, the pitting current versus time relations fit the Engell-Stolica equation. (orig.).

  20. On the field dependent surface resistance of niobium on copper cavities

    CERN Document Server

    Junginger, Tobias

    2015-01-01

    The surface resistance Rs of superconducting cavities prepared by sputter coating a thin niobium film on a copper substrate increases significantly stronger with the applied RF field compared to cavities of bulk material. A possible cause is that due to the thermal boundary resistance between the copper substrate and the niobium film Rs is enhanced due to global heating of the inner cavity wall. Introducing helium gas in the cavity and measuring its pressure as a function of applied field allowed to conclude that the inner surface of the cavity is heated up by only 60+/-60 mK when Rs increases with Eacc by 100 nOhm. This is more than one order of magnitude less than what one would expect from global heating. Additionally the effect of cooldown speed and low temperature baking have been investigated in the framework of these experiments. It is shown that for current state of the art niobium on copper cavities there is only a detrimental effect of low temperature baking. A fast cooldown results in a lowered Rs.

  1. Copper ion implanted aluminum nitride dilute magnetic semiconductors (DMS) prepared by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Shah, A., E-mail: attaullah77@yahoo.com [National Institute of Lasers and Optronics (NILOP), PO Nilore, Islamabad (Pakistan); DMME, Pakistan Institute of Engineering and Applied Science (PIEAS), PO Nilore, Islamabad (Pakistan); Ahmad, Jamil [DMME, Pakistan Institute of Engineering and Applied Science (PIEAS), PO Nilore, Islamabad (Pakistan); Ahmad, Ishaq [Experimental Physics Lab, National Center for Physics (NCP), Islamabad (Pakistan); Mehmood, Mazhar [DMME, Pakistan Institute of Engineering and Applied Science (PIEAS), PO Nilore, Islamabad (Pakistan); Mahmood, Arshad [National Institute of Lasers and Optronics (NILOP), PO Nilore, Islamabad (Pakistan); Rasheed, Muhammad Asim [DMME, Pakistan Institute of Engineering and Applied Science (PIEAS), PO Nilore, Islamabad (Pakistan)

    2014-10-30

    Highlights: • AlN:Cu dilute magnetic semiconductors were successfully prepared by molecular beam epitaxy followed by Cu{sup +} implantation. • Room temperature ferromagnetism was observed after annealing the samples at appropriate temperature. • XRD and Raman spectrometry excluded the possibility of formation of any secondary phases. • By doping intrinsically nonmagnetic dopants (Cu), it has been proved experimentally that their precipitates do not contribute to ferromagnetism. • The reason for ferromagnetism in Cu-doped AlN as observed was explained on the basis of p–d hybridization mechanism (Wu et al.). - Abstract: Diluted magnetic semiconductor (DMS) AlN:Cu films were fabricated by implanting Cu{sup +} ions into AlN thin films at various ion fluxes. AlN films were deposited on c-plane sapphire by molecular beam epitaxy followed by Cu{sup +} ion implantation. The structural and magnetic characterization of the samples was performed through Rutherford backscattering and channeling spectrometry (RBS/C), X-ray diffraction (XRD), Raman spectroscopy, vibrating sample magnetometer (VSM) and SQUID. Incorporation of copper into the AlN lattice was confirmed by RBS, while XRD revealed that no new phase was formed as a result of ion implantation. RBS also indicated formation of defects as a result of implantation process and the depth and degree of damage increased with an increase in ion fluence. Raman spectra showed only E{sub 2} (high) and A{sub 1} (LO) modes of wurtzite AlN crystal structure and confirmed that no secondary phases were formed. It was found that both Raman modes shift with Cu{sup +} fluences, indicating that Cu ion may go to interstitial or substitutional sites resulting in distortion or damage of lattice. Although as implanted samples showed no magnetization, annealing of the samples resulted in appearance of room temperature ferromagnetism. The saturation magnetization increased with both the annealing temperature as well as with ion

  2. DNA degradation by aqueous extract of Aloe vera in the presence of copper ions.

    Science.gov (United States)

    Naqvi, Shoa; Ullah, M F; Hadi, S M

    2010-06-01

    The plant Aloe vera has long been used in medicine, as dietary supplements and for cosmetic purposes. Aloe vera extracts are a rich source of polyphenols, such as aloin and aloe emodin and have shown a wide range of pharmacological properties, including anti-inflammatory and anti-cancer properties. The bioactive component aloe emodin has been reported to induce apoptosis in various cancer cell lines. Many of the biological activities of Aloe vera have been attributed to its antioxidant properties. However, most plant-derived polyphenols that are also present in Aloe vera may exhibit pro-oxidant properties either alone or in the presence of transition metals, such as copper. Previous reports from this laboratory have implicated the pro-oxidant action as one of the mechanisms for their anti-cancer properties. In the present paper, we show that aqueous extract of Aloe vera is also able to cause DNA degradation in the presence of copper ions. Further, the extract is also able to reduce Cu(II) to Cu(I) and generate reactive oxygen species, such as superoxide anion and hydroxyl radicals in a dose-dependent manner, which correlates with ability of the extract to cause DNA breakage. Thus, the study shows that in addition to antioxidant activity, Aloe vera extract also possess pro-oxidant properties, leading to oxidative DNA breakage.

  3. Negative ion photoelectron spectroscopy of the copper-aspartic acid anion and its hydrated complexes

    Science.gov (United States)

    Li, Xiang; Wang, Haopeng; Bowen, Kit H.; Martínez, Ana; Salpin, Jean-Yves; Schermann, Jean-Pierre

    2010-08-01

    Negative ions of copper-aspartic acid Cu(Asp)- and its hydrated complexes have been produced in the gas phase and studied by anion photoelectron spectroscopy. The vertical detachment energies (VDE) of Cu(Asp)- and Cu(Asp)-(H2O)1,2 were determined to be 1.6, 1.95, and 2.20 eV, respectively. The spectral profiles of Cu(Asp)-(H2O)1 and Cu(Asp)-(H2O)2 closely resembled that of Cu(Asp)-, indicating that hydration had not changed the structure of Cu(Asp)- significantly. The successive shifts to higher electron binding energies by the spectra of the hydrated species provided measures of their stepwise solvation energies. Density functional calculations were performed on anionic Cu(Asp)- and on its corresponding neutral. The agreement between the calculated and measured VDE values implied that the structure of the Cu(Asp)- complex originated with a zwitterionic form of aspartic acid in which a copper atom had inserted into the N-H bond.

  4. Detoxification of copper fungicide using EDTA-modified cellulosic ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-02-04

    Feb 4, 2009 ... ugh the R2 values are high (and good), for the Longmuir isotherm, the .... mass transfer resistance and the third is intraparticle ... Chromium and Copper ions from aqueous solutions by shea Butter ... Batch nickel removal from.

  5. Copper-zinc superoxide dismutase-mediated redox regulation of bortezomib resistance in multiple myeloma.

    Science.gov (United States)

    Salem, Kelley; McCormick, Michael L; Wendlandt, Erik; Zhan, Fenghuang; Goel, Apollina

    2015-01-01

    Multiple myeloma (MM) is an incurable B-cell malignancy. The proteasome inhibitor bortezomib (BTZ) is a frontline MM drug; however, intrinsic or acquired resistance to BTZ remains a clinical hurdle. As BTZ induces oxidative stress in MM cells, we queried if altered redox homeostasis promotes BTZ resistance. In primary human MM samples, increased gene expression of copper-zinc superoxide dismutase (CuZnSOD or SOD1) correlated with cancer progression, high-risk disease, and adverse overall and event-free survival outcomes. As an in vitro model, human MM cell lines (MM.1S, 8226, U266) and the BTZ-resistant (BR) lines (MM.1SBR, 8226BR) were utilized to determine the role of antioxidants in intrinsic or acquired BTZ-resistance. An up-regulation of CuZnSOD, glutathione peroxidase-1 (GPx-1), and glutathione (GSH) were associated with BTZ resistance and attenuated prooxidant production by BTZ. Enforced overexpression of SOD1 induced BTZ resistance and pharmacological inhibition of CuZnSOD with disulfiram (DSF) augmented BTZ cytotoxicity in both BTZ-sensitive and BTZ-resistant cell lines. Our data validates CuZnSOD as a novel therapeutic target in MM. We propose DSF as an adjuvant to BTZ in MM that is expected to overcome intrinsic and acquired BTZ resistance as well as augment BTZ cytotoxicity.

  6. Thermal resistance of indium coated sapphire–copper contacts below 0.1K

    CERN Document Server

    Eisel, T; Koettig, T

    2014-01-01

    High thermal resistances exist at ultra-low temperatures for solid-solid interfaces. This is especially true for pressed metal-sapphire joints, where the heat is transferred by phonons only. For such pressed joints it is difficult to achieve good physical, i.e. thermal contacts due to surface irregularities in the microscopic or larger scale. Applying ductile indium as an intermediate layer reduces the thermal resistance of such contacts. This could be proven by measurements of several researchers. However, the majority of the measurements were performed at temperatures higher than 1 K. Consequently, it is difficult to predict the thermal resistance of pressed metal-sapphire joints at temperatures below 1 K. In this paper the thermal resistances across four different copper-sapphire-copper sandwiches are presented in a temperature range between 30 mK and 100 mK. The investigated sandwiches feature either rough or polished sapphire discs (empty set 20 mm x 1.5 mm) to investigate the phonon scattering at the bo...

  7. Application of magnetic particles modified with amino groups to adsorb copper ions in aqueous solution

    Institute of Scientific and Technical Information of China (English)

    Yafen Lin; Huawei Chen; Kaelong Lin; Boryann Chen; Chyowsan Chiou

    2011-01-01

    A magnetic adsorbent can be easily recovered from treated water by magnetic force, without requiring further downstream treatment.In this research, amine-functionalized silica magnetite has been synthesized using N-[3-(trimethoxysilyl)propyl]-ethylenediamine (TPED) as a surface modification agent.The synthesized magnetic amine adsorbents were used to adsorb copper ions in an aqueous solution in a batch system, and the maximum adsorption was found to occur at pH 5.5 ± 0.1.The adsorption equilibrium data fitted the Langmuir isotherm equation reasonably well, with a maximum adsorption capacity of 10.41 mg/g.A pseudo second-order model could best describe the adsorption kinetics, and the derived activation energy was 26.92 kJ/mol.The optimum condition to desorb Cu2+ from NH2/SiO2/Fe3O4 was provided by a solution with 0.1 mol/L HNO3.

  8. Colorimetric detection of trace copper ions based on catalytic leaching of silver-coated gold nanoparticles.

    Science.gov (United States)

    Lou, Tingting; Chen, Lingxin; Chen, Zhaopeng; Wang, Yunqing; Chen, Ling; Li, Jinhua

    2011-11-01

    A colorimetric, label-free, and nonaggregation-based silver coated gold nanoparticles (Ag/Au NPs) probe has been developed for detection of trace Cu(2+) in aqueous solution, based on the fact that Cu(2+) can accelerate the leaching rate of Ag/Au NPs by thiosulfate (S(2)O(3)(2-)). The leaching of Ag/Au NPs would lead to dramatic decrease in the surface plasmon resonance (SPR) absorption as the size of Ag/Au NPs decreased. This colorimetric strategy based on size-dependence of nanoparticles during their leaching process provided a highly sensitive (1.0 nM) and selective detection toward Cu(2+), with a wide linear detection range (5-800 nM) over nearly 3 orders of magnitude. The cost-effective probe allows rapid and sensitive detection of trace Cu(2+) ions in water samples, indicating its potential applicability for the determination of copper in real samples.

  9. Synthesis and characteristics of a novel artificial hapten using the copper mercaptide of penicillenic acid from penicillin G for immunoassay of heavy metal ions.

    Science.gov (United States)

    Xu, Wu; Xie, Peng; Fan, Liuyin; Cao, Chengxi; Xi, Tao; Zhou, Pei

    2011-09-01

    In this paper, we describe the synthesis of a novel copper ion hapten using the copper mercaptide of penicillenic acid (CMPA) derived from penicillin. Results from tests with immune rabbits indicate that: (i) A new antigen synthesized with CMPA has good stability and is safe for immunizing animals with no toxic phenomena being found in animal experiments; (ii) the immunogenic antigen (CMPA-BSA) can stimulate the immune system to produce specific antibodies with high titrations, up to 150000; and (iii) antibodies in antisera showed higher affinity to OVA-GSH-CuCl than OVA-GSH, which indicates that the antibodies have specific affinity towards copper ions. These results confirm that the novel hapten and relevant antigen for copper ion have been successfully synthesized, giving progress towards an immunoassay for copper ions in environmental and food samples.

  10. High resistance to sulfur poisoning of Ni with copper skin under electric field

    Science.gov (United States)

    Xu, Xiaopei; Zhang, Yanxing; Yang, Zongxian

    2017-02-01

    The effects of sulfur poisoning on the (1 0 0), (1 1 0) and (1 1 1) surfaces of pure Ni and Cu/Ni alloy are studied in consideration of the effect of electric field. The effects of Cu dopants on the S poisoning characteristics are analyzed by the means of the density functional theory results in combination with thermodynamics data using the ab initio atomistic thermodynamic method. When the Cu concentration increases to 50% on the surface layer of the Cu/Ni alloy, the (1 1 0) surface becomes the most vulnerable to the sulfur poisoning. Ni with a copper skin can mostly decrease the sulfur poisoning effect. Especially under the electric field of 1.0 V/Å, the sulfur adsorption and phase transition temperature can be further reduced. We therefore propose that Ni surfaces with copper skin can be very effective to improve the resistance to sulfur poisoning of the Ni anode under high electric field.

  11. Pyruvic Oxime Nitrification and Copper and Nickel Resistance by a Cupriavidus pauculus, an Active Heterotrophic Nitrifier-Denitrifier

    Directory of Open Access Journals (Sweden)

    Miguel Ramirez

    2014-01-01

    Full Text Available Heterotrophic nitrifiers synthesize nitrogenous gasses when nitrifying ammonium ion. A Cupriavidus pauculus, previously thought an Alcaligenes sp. and noted as an active heterotrophic nitrifier-denitrifier, was examined for its ability to produce nitrogen gas (N2 and nitrous oxide (N2O while heterotrophically nitrifying the organic substrate pyruvic oxime [CH3–C(NOH–COOH]. Neither N2 nor N2O were produced. Nucleotide and phylogenetic analyses indicated that the organism is a member of a genus (Cupriavidus known for its resistance to metals and its metabolism of xenobiotics. The microbe (a Cupriavidus pauculus designated as C. pauculus strain UM1 was examined for its ability to perform heterotrophic nitrification in the presence of Cu2+ and Ni2+ and to metabolize the xenobiotic phenol. The bacterium heterotrophically nitrified well when either 1 mM Cu2+ or 0.5 mM Ni2+ was present in either enriched or minimal medium. The organism also used phenol as a sole carbon source in either the presence or absence of 1 mM Cu2+ or 0.5 mM Ni2+. The ability of this isolate to perform a number of different metabolisms, its noteworthy resistance to copper and nickel, and its potential use as a bioremediation agent are discussed.

  12. Atom probe field ion microscopy of high resistivity materials

    Energy Technology Data Exchange (ETDEWEB)

    Sibrandij, S.J.; Larson, D.J.; Miller, M.K.

    1998-02-01

    Over the last 30 years the atom probe has proved to be a powerful tool for studying nanometer-sized compositional fluctuations in a wide range of metallic alloys but has had only limited applications to semiconductors and ceramics. One of the primary reasons for this difference is the higher resistivity of semiconducting and ceramic specimens. Because of this high resistivity, the high voltage field evaporation pulse is attenuated before it reaches the apex of the specimen thereby making the pulse ineffective for field evaporation. Experiments have demonstrated that both variants of the voltage-pulsed atom probe (i.e., those instruments in which the field evaporation pulse is applied directly to the specimen and those in which the negative pulse is applied to a counter electrode in front of the specimen) are equally affected. In this overview, the limits of applicability of the voltage-pulsed atom probe to high resistivity materials are examined. In this study, a wide range of materials have been examined to determine whether field ion microscopy and voltage-pulsed field evaporation can be achieved and the results are summarized in the report. Field ion microscopy including dc field evaporation was possible for all materials except bulk ceramic insulators and glasses. Field ion microscopy requires some conductivity both to achieve a high electric field at the apex of the specimen, and also to support the field ion current. In contrast, voltage-pulsed field evaporation requires transmission of the pulse to the apex of the specimen. All metallic alloys including high resistance alloys and metallic glasses were successfully field evaporated with a voltage pulse. Specimens that were produced from bulk material of several conducting ceramics including MoSi, TiB and TiC were also successfully field evaporated with a voltage pulse.

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

    Science.gov (United States)

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

    2017-01-01

    Increased copper (Cu) and iron (Fe) levels in liver and brain are associated to oxidative stress and damage with increased phospholipid oxidation process. The aim of this work was to assess the toxic effects of Cu(2+) and Fe(3+) addition to rat liver mitochondria by determining mitochondrial respiration in states 3 (active respiration) and 4 (resting respiration), and phospholipid peroxidation. Both, Cu(2+) and Fe(3+) produced decreases in O2 consumption in a concentration-dependent manner in active state 3: both ions by 42% with malate-glutamate as complex I substrate (concentration for half maximal response (C50) 60μM Cu(2+) and 1.25mM Fe(3+)), and with succinate as complex II substrate: 64-69% with C50 of 50μM Cu(2+) and with C50 of 1.25mM of Fe(3+). Respiratory control decreased with Cu(2+) (C50 50μM) and Fe(3+) (C50 1.25-1-75mM) with both substrates. Cu(2+) produced a 2-fold increase and Fe(3+) a 5-fold increase of thiobarbituric acid-reactive substances (TBARS) content from 25μM Cu(2+) (C50 40μM) and from 100μM Fe(3+) (C50 1.75mM). Supplementations with Cu(2+) and Fe(3+) ions induce mitochondrial dysfunction with phospholipid peroxidation in rat liver mitochondria. Although is proved that a Fenton/Haber Weiss mechanism of oxidative damage occurs in metal-ion induced mitochondrial toxicity, slightly different responses to the metal ions suggest some differences in the mechanism of intracellular toxicity. The decreased rates of mitochondrial respiration and the alteration of mitochondrial function by phospholipid and protein oxidations lead to mitochondrial dysfunction, cellular dyshomeostasis and cell death.

  14. Adsorption of lead and copper ions from aqueous effluents on rice husk ash in a dynamic system

    Directory of Open Access Journals (Sweden)

    M. G. A. Vieira

    2014-06-01

    Full Text Available This study evaluated the kinetic adsorption of Pb and Cu ions using rice husk ash as adsorbent in a fixed bed. The maximum adsorption capacities obtained for lead and copper ions in the fixed bed were 0.0561 and 0.0682 mmol/g (at 20 ºC, respectively. The thermodynamic studies indicated that the lead adsorption process was exothermic and spontaneous, while the copper adsorption process was endothermic and spontaneous. Characterization results indicated the presence of several functional groups, amorphous silica and a fibrous and longitudinal structure of rice husks. Rice husk ash (RHA from northern Brazil can be used as a bioadsorbent for the individual removal of Pb(II and Cu(II ions from metal-containing effluents.

  15. Femtomole level photoelectrochemical aptasensing for mercury ions using quercetin-copper(II) complex as the DNA intercalator.

    Science.gov (United States)

    Li, Hongbo; Xue, Yan; Wang, Wei

    2014-04-15

    An ultrasensitive and selective photoelectrochemical (PEC) aptasensor for mercury ions was first fabricated based on perylene-3, 4, 9, 10-tetracarboxylic acid/graphene oxide (PTCA/GO) heterojunction using quercetin-copper(II) complex intercalated into the poly(dT)-poly(dA) duplexes. Both the PTCA/GO heterojunction and the quercetin-copper(II) complex are in favor of the sensitivity for the fabricated PEC aptasensor due to band alignment and strong reduction capability, respectively. And they efficiently promote the separation of photoexcited carriers and enhance the photocurrent. The formation of thymine-Hg(2+)-thymine coordination chemistry resulted in the dehybridization of poly(dT)-poly(dA) duplexes and then the intercalator quercetin-copper(II) complex broke away from the surface of the PEC aptasensor. As the concentration of mercury ions increased, the photocurrent gradually decreased. The electrode response for mercury ions detection was in the linear range from 0.01 pmol L(-1) to 1.00 pmol L(-1) with the detection limit of 3.33 fmol L(-1). The label-free PEC aptasensor has excellent performances with ultrasensitivity and good selectivity besides the advantage of economic and facile fabrication. The strategy of quercetin-copper(II) complex as a novel DNA intercalator paves a new way to improve the performances for PEC sensors. © 2013 Published by Elsevier B.V.

  16. Solid-phase extraction of copper, iron and zinc ions on Bacillus thuringiensis israelensis loaded on Dowex optipore V-493

    Energy Technology Data Exchange (ETDEWEB)

    Tuzen, Mustafa; Melek, Esra [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey); Soylak, Mustafa [Erciyes University, Faculty of Science and Arts, Chemistry Department, 38039 Kayseri (Turkey)], E-mail: msoylak@gmail.com

    2008-11-30

    Bacillus thuringiensis israelensis loaded on Dowex optipore V-493 as new adsorbent for the separation-preconcentration of heavy metal ions has been proposed. The analytical conditions for the quantitative recoveries of copper(II), iron(III) and zinc(II) including pH, amounts of adsorbent, sample volume, etc. were investigated. The influences of alkaline and earth alkaline ions were also reported. The recovery values for the analytes are generally higher than 95%. The preconcentration factor was 37. The limit of detections of the analyte ions (k = 3, N = 21) were 1.14 {mu}g L{sup -1} for copper, 2.01 {mu}g L{sup -1} for iron and 0.14 {mu}g L{sup -1} for zinc. The relative standard deviations of the determinations were found to be lower than 9%. The procedure was validated by analyzing copper, iron and zinc contents in two certified reference materials, NRCC-SLRS-4 Riverine water and NIST SRM 1515 Apple leaves. Agreements between the obtained results and the certified values were achieved. The developed preconcentration method was applied in the flame atomic absorption spectrometric determination of copper, iron and zinc in several samples including a multivitamin-multimineral tablet, dialysis solutions, natural waters and some food samples.

  17. 铜粉处理酸性镀铜溶液中氯离子的机理%Mechanism of Treating Chloride Ion in Acidic Copper Plating Bath with Copper Powder

    Institute of Scientific and Technical Information of China (English)

    郭崇武

    2011-01-01

    阐明了用铜粉处理酸性镀铜溶液中氯离子的机理,理论分析和实验表明,在酸性镀铜溶液中,Cu2+离子与铜粉反应生成Cu+离子,同时氯离子与Cu+离子反应生成氯化亚铜沉淀.向镀液中加铜粉1g/L,氯离子的起始质量浓度为174mg/L时,氯离子的去除率为58.9%,而向镀液中加锌粉1g/L,氯离子的去除率为47.0%,用铜粉处理氯离子的效率较高.%The mechanism of treating chloride ion in acidic copper plating bath by using copper powder was illustrated. Theoretical analyses and experimental tests indicated that in acidic copper plating solution Cu2+ ion could react with copper powder to form Cu + ion and the Cu + ion could react with chloride ion in the solution to produce cuprous chloride precipitation. When the initial mass concentration of the chloride ions in the acidic copper plating solution was 174 mg/L, the elimination rate of chloride ions after adding 1 g/L copper powders to the solution was 58.9% while that after adding 1 g/L zinc powders was 47.0%. This indicates that the treatment efficiency of chloride ion in the acidic copper plating solution with copper powders is higher than that with zinc powders.

  18. CYCLIC VOLTAMMETRY STUDIES OF COPPER (II AND TELLURIUM (IV IONS IN ACIDIC AQUEOUS SOLUTIONS FOR THIN FILM DEPOSITION

    Directory of Open Access Journals (Sweden)

    SARAVANAN NAGALINGAM

    2014-05-01

    Full Text Available Cyclic voltammetry studies of copper (II and tellurium (IV ions in acidic aqueous solutions were carried out to determine the optimum condition for copper telluride thin film deposition. The voltammetry studies include reversible scans at different solution pH. Based on the voltammogram, suitable deposition conditions was determined to be in the range of -0.35 V to -0.45 V versus Ag/AgCl at pH values between 2.0 to 2.2 under non diffusion-limited conditions.

  19. Recovery of Copper Ions from Wastewater by Hollow Fiber Supported Emulsion Liquid Membrane

    Institute of Scientific and Technical Information of China (English)

    郑辉东; 陈晶晶; 王碧玉; 赵素英

    2013-01-01

    Recovery of copper ions from wastewater using a hollow fiber supported emulsion liquid membrane (HFSELM) was studied with LIX984N as carrier, kerosene as diluents, and sulfuric acid solution as stripping phase. Effects of compositions of feed and emulsion liquid phase, flow rates on both sides of membrane, and hollow fiber module parameters were investigated. The stability of the emulsion liquid phase without surfactant and the effect of buffer in the feed phase on the extraction rate were also evaluated. It is found that the stability of the emulsion phase without surfactant is poor. Higher flow velocity gives shorter residence time for the emulsion liquid phase on the tube side, reducing the effect of particle coalescence on the separation process. The extraction rate increases with the increase of feed phase pH, carrier concentration, hydrogen ion concentration in the stripping phase, and ef-fective hollow fiber area. The phase ratio in the emulsion liquid phase has a negative effect on extraction rate. The flow rates on both sides have little influence on the extraction performance of the HFSELM, while buffer addition in the feed solution improves the extraction efficiency.

  20. Study of the interaction mechanism in the biosorption of copper(II) ions onto posidonia oceanica and peat

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo, Marta; Marzal, Paula; Gabaldon, Carmen [Departamento de Ingenieria Quimica, Escuela Tecnica Superior de Ingenieria, Universitat de Valencia, Valencia (Spain); Silvetti, Margherita; Castaldi, Paola [Dipartimento di Scienze Ambientali e Agrarie e Biotecnologie Agro-Alimentari, Sez. Chimica Agraria ed Ambientale, University of Sassari, Sassari (Italy)

    2012-04-15

    A systematic approach was used to characterize the biosorption of copper(II) onto two biosorbents, Posidonia oceanica and peat, focusing on the interaction mechanisms, the copper(II) sorption-desorption process and the thermal behavior of the biosorbents. Sorption isotherms at pH 4-6 were obtained and the experimental data were fitted to the Langmuir model with a maximum uptake (q{sub max}) at pH 6 of 85.78 and 49.69 mg g{sup -1}, for P. oceanica and peat, respectively. A sequential desorption (SD) with water, Ca(NO{sub 3}){sub 2}, and EDTA was applied to copper-saturated biosorbents. Around 65-70% copper(II) were desorbed with EDTA, indicating that this heavy metal was strongly bound. The reversibility of copper(II) sorption was obtained by desorption with HCl and SD. Fourier transform IR spectroscopy (FTIR) analysis detected the presence of peaks associated with OH groups in aromatic and aliphatic structures, CH, CH{sub 2}, and CH{sub 3} in aliphatic structures, COO{sup -} and COOH groups and unsaturated aromatic structures on the surface of both biosorbents, as well as peaks corresponding to Si-O groups on the surface of peat. The results of SEM-EDX and FTIR analysis of copper-saturated samples demonstrated that ion exchange was one of the mechanisms involved in copper(II) retention. Thermal analysis of biosorbent samples showed that copper(II) sorption-desorption processes affected the thermal stability of the biosorbents. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Releasing of Cupric Ion of Three types of Copper-bearing Intrauterine Contraceptive Device in Simulated Uterine Fluid

    Institute of Scientific and Technical Information of China (English)

    Jie GAO; Ying LI; Jian-ping LIU; Xuan GU

    2007-01-01

    Objective To compare the cupric ion releasing in vitro of the three IUDs.Methods The stability of cupric ion releasing of IUDs including TCu 380A IUD (TCu 380A), Multiload Cu375 IUD (MCu 375) and Yuangong 365 copper-bearing indomethacin-releasing IUD (Yuangong 365) by the determination of cupric ion releasing in simulated uterine fluid. The simulated uterine fluid was used for releasing media. Copper ion was determined by flame atomic absorption spectrometerResults The cupric ion releasing of three IUDs were instable at the beginning and tend to be stable gradually. In the stable phase, the average level of cupric ion releasing of TCu380A, MCu375 and Yuangong 365 were 4.25±2.71 -7.62±6.42 μg,4.92±1.23 -8.62±3.08 μg and 2.19±0.40-4.68±1.66 μg, respectively. TCu380A had higher instable releasing level than those of Yuangong 365 (P<0. 05).Conclusion TCu 380A and MCu 375 showed a "burst release" during the first few days and the former was of great significance(P<0. 05). The initial cupric ion releasing of Yuangong 365 appeared to be the lowest, followed by MCu375 and TCu380A in a releasing order.

  2. Simultaneous and sensitive analysis of aliphatic carboxylic acids by ion-chromatography using on-line complexation with copper(II) ion.

    Science.gov (United States)

    Kemmei, Tomoko; Kodama, Shuji; Yamamoto, Atsushi; Inoue, Yoshinori; Hayakawa, Kazuichi

    2015-01-02

    A new approach to ion chromatography is proposed to improve the UV detection of aliphatic carboxylic acids separated by anion-exchange chromatography. When copper(II) ion added to the mobile phase, it forms complexes with carboxylic acids that can be detected at 240 nm. The absorbance was found to increase with increasing copper(II) ion concentration. The retention times of α-hydroxy acids were also found to depend on the copper(II) ion concentration. Addition of acetonitrile to the mobile phase improved the separation of aliphatic carboxylic acids. The detection limits of the examined carboxylic acids (formate, glycolate, acetate, lactate, propionate, 3-hydroxypropionate, n-butyrate, isobutyrate, n-valerate, isovalerate, n-caproate) calculated at S/N=3 ranged from 0.06 to 3 μM. The detector signal was linear over three orders of magnitude of carboxylic acid concentration. The proposed method was successfully applied to analyze aliphatic carboxylic acids in rainwater and bread.

  3. Superhydrophobic copper surfaces fabricated by fatty acid soaps in aqueous solution for excellent corrosion resistance

    Science.gov (United States)

    Xu, Wenlong; Hu, Yuanyuan; Bao, Wenda; Xie, Xiaoyu; Liu, Yiran; Song, Aixin; Hao, Jingcheng

    2017-03-01

    A simple and safe one-step immersion method was developed to obtain the stable superhydrophobic copper surfaces with excellent corrosion resistance ability using fatty acids in water-medium instead of ethanol. An organic alkali, N,N-dimethylcyclohexylamine (DMCHA), was chosen to solve the poor solubility of fatty acids in water and the high Krafft point of carboxylate salts with inorganic counterions. The superhydrophobic property can be realized in a much quicker process (7.5 min) in aqueous solution than in ethanol (more than 2 d), which is universally feasible for the fabrication of superhydrophobic metal surfaces in industry scale, thereby greatly increasing the safety in industrial manufacture.

  4. Bio sorption of copper ions with biomass of algae and dehydrated waste of olives; Biosorcion de iones cobre con biomasa de algas y orujos deshidratados

    Energy Technology Data Exchange (ETDEWEB)

    Tapia, P.; Santander, M.; Pavez, O.; Valderrama, L.; Guzman, D.; Romero, L.

    2011-07-01

    They were carried out experiments of biosorption batch and in continuous to remove copper from aqueous solutions using as adsorbents green algae and olive residues under virgins conditions and chemically activated. The results of batch bio sorption indicate that the algae present mayor elimination capacities than the waste of olives, with uptakes of copper of the order of 96 % using activated algae with dissolution of Na{sub 2}SO{sub 4} under the optimum conditions. The results of the columns tests show that the virgin algae permits the removal of more copper ions than the activate algae, with removal efficiency of 98 % during the firth 20 min, a breakthrough time of 240 min and a saturation at time of 600 min. In the second cycle the regenerated biomass showed a best performance indicating that they can be used for another bio sorption cycle. (Author) 42 refs.

  5. [Study on the release of copper ion and corrosion for intrauterine contraceptive device with two kinds of Cu-containing stent].

    Science.gov (United States)

    Zou, Fengping; Huang, Shuze; Ji, Rong; Ding, Biao; Yao, Tianping

    2014-05-01

    Two kinds of Cu-containing intrauterine contraceptive device (Cu-IUD) has been evaluated through the study on the release of copper ion and corrosion of copper surface in artificially formulated fluid. The result showed that the copper ions were released profusely from the stainless steel stents Cu-IUD in the first week of soak (25-12 microg/d), and then it became slowly and steady. The release of the copper ions from the titanium nickel shape memory alloy stents Cu-IUD were always slowly and steady in two months (0.5-5 microg/d). It obviously shows that the corrosion on copper surface of stainless steel stents Cu-IUD were more serious than titanium nickel shape memory alloy stents Cu-IUD by using 200 times microscope testing before and after soaking in formulated fluid.

  6. Cloud point extraction and flame atomic absorption spectrometry combination for copper(II) ion in environmental and biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Shokrollahi, Ardeshir [Chemistry Department, Yasouj University, Yasouj 75914-353 (Iran, Islamic Republic of)], E-mail: ashokrollahi@mail.yu.ac.ir; Ghaedi, Mehrorang [Chemistry Department, Yasouj University, Yasouj 75914-353 (Iran, Islamic Republic of)], E-mail: m_ghaedi@mail.yu.ac.ir; Hossaini, Omid; Khanjari, Narges [Chemistry Department, Yasouj University, Yasouj 75914-353 (Iran, Islamic Republic of); Soylak, Mustafa [Chemistry Department, University of Erciyes, 38039 Kayseri (Turkey)

    2008-12-30

    A cloud point extraction procedure was presented for the preconcentration of copper(II) ion in various samples. After complexation by 4-(phenyl diazenyl) benzene-1,3-diamine (PDBDM) (chrysoidine), copper(II) ions were quantitatively recovered in Triton X-114 after centrifugation. 0.5 ml of methanol acidified with 1.0 mol L{sup -1} HNO{sub 3} was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). The influence of analytical parameters including ligand, Triton X-114 and HNO{sub 3} concentrations, bath temperature, heating time, centrifuge rate and time were optimized. The effect of the matrix ions on the recovery of copper(II) ions was investigated. The detection limit (3S.D.{sub b}/m, n = 10) of 0.6 ng mL{sup -1} along with preconcentration factor of 30 and enrichment factor of 41.1 with R.S.D. of 1.0% for Cu was achieved. The proposed procedure was applied to the analysis of various environmental and biological samples.

  7. Use of ligand-modified micellar-enhanced ultrafiltration to selectively separate copper ions from wastewater streams

    Energy Technology Data Exchange (ETDEWEB)

    Shadizadeh, S.B.

    1992-12-31

    The selective removal of target ions from an aqueous solution containing ions of like charge by ligand-modified micellar-enhanced ultrafiltration (LM-MEUF), is presented. In LM-MEUF, surfactant and specially tailored ligand are added to the contaminated stream. The surfactant forms aggregates called micelles, the hydrocarbon core of which the ligand complexed with the target species will solubilize. The surfactant is chosen to have the same charge type as the target ion; therefore, other ions (with similar charge) will not associate with the micelle, which makes the separation of the target ion selective. The solution is then processed by ultrafiltration, using a membrane with pore size small enough to block the passage of the micelles. In this study the divalent copper is the target ion in the solution containing divalent calcium. The surfactant is cetylpyridinium chloride (CPC) and the ligand is 4-hexadecyloxybenzyliminodiacetic acid (C{sub 16}BIDA). Experiments were conducted with batch stirred cells and the results have been compared to separation that take place under a variety of conditions in the LM-MEUF process. Rejections of copper of up to 99.8% are observed, with almost no rejection of calcium, showing that LM-MEUF has excellent selectivity and separation efficiency.

  8. Removal of Copper(II and Zinc(II Ions From Aqueous Solution by Chemical Treatment of Coal Fly Ash

    Directory of Open Access Journals (Sweden)

    Eleonora Sočo

    2015-12-01

    Full Text Available The aim of this study was to investigate the chemical modifications of coal fly ash (CFA treated with HNO3 or ammonium acetate (AcNH4 or NaOH or sodium diethyldithiocarbamate (NaDDTC as an adsorbent for the removal of copper(II and zinc(II ions from aqueous solution. The morphology of fly ash grains before and after modification was examined via X-ray diffraction (XRD and images of scanning electron microscope (SEM. Adsorption of copper(II and zinc(II ions was conducted under batch process at different duration, concentrations and temperature of the suspension. Equilibrium experiments shows that the selectivity of CFA-NaOH nanoparticles towards Cu(II ions is greater than that of Zn(II ions, which is related to their hydrated ionic radius and first hydrolysis equilibrium constant. The adsorption isotherms were described by Langmuir and Freundlich models. Kinetic data revealed that the adsorption fits well by the pseudo-second-order rate model with high regression coefficients. Thermodynamic parameters suggested that the immobilization Cu(II and Zn(II ions onto CFA-NaOH is a spontaneous process. Results demonstrated that the treating coal fly ash with alkaline solution was a promising way to enhance Cu(II and Zn(II ions adsorption.

  9. Coupled stress-strain and electrical resistivity measurements on copper based shape memory single crystals

    Directory of Open Access Journals (Sweden)

    Gonzalez Cezar Henrique

    2004-01-01

    Full Text Available Recently, electrical resistivity (ER measurements have been done during some thermomechanical tests in copper based shape memory alloys (SMA's. In this work, single crystals of Cu-based SMA's have been studied at different temperatures to analyse the relationship between stress (s and ER changes as a function of the strain (e. A good consistency between ER change values is observed in different experiments: thermal martensitic transformation, stress induced martensitic transformation and stress induced reorientation of martensite variants. During stress induced martensitic transformation (superelastic behaviour and stress induced reorientation of martensite variants, a linear relationship is obtained between ER and strain as well as the absence of hys teresis. In conclusion, the present results show a direct evidence of martensite electrical resistivity anisotropy.

  10. Paths and determinants for Penicillium janthinellum to resist low and high copper.

    Science.gov (United States)

    Xu, Jian; Chen, Guo-Li; Sun, Xue-Zhe; Fan, Xian-Wei; You-Zhi, Li

    2015-08-12

    Copper (Cu) tolerance was well understood in fungi yeasts but not in filamentous fungi. Filamentous fungi are eukaryotes but unlike eukaryotic fungi yeasts, which are a collection of various fungi that are maybe classified into different taxa but all characterized by growth as filamentous hyphae cells and with a complex morphology. The current knowledge of Cu resistance of filamentous fungi is still fragmental and therefore needs to be bridged. In this study, we characterized Cu resistance of Penicillium janthinellum strain GXCR and its Cu-resistance-decreasing mutants (EC-6 and UC-8), and conducted sequencing of a total of 6 transcriptomes from wild-type GXCR and mutant EC-6 grown under control and external Cu. Taken all the results together, Cu effects on the basal metabolism were directed to solute transport by two superfamilies of solute carrier and major facilitator, the buffering free CoA and Acyl-CoA pool in the peroxisome, F-type H(+)-transporting ATPases-based ATP production, V-type H(+)-transporting ATPases-based transmembrane transport, protein degradation, and alternative splicing of pre-mRNAs. Roles of enzymatic and non-enzymatic antioxidants in resistance to low and high Cu were defined. The backbone paths, signaling systems, and determinants that involve resistance of filamentous fungi to high Cu were determined, discussed and outlined in a model.

  11. Variation in adult stress resistance does not explain vulnerability to climate change in copper butterflies.

    Science.gov (United States)

    Klockmann, Michael; Wallmeyer, Leonard; Fischer, Klaus

    2017-03-15

    Ongoing climate change is a major threat to biodiversity. However, although many species clearly suffer from ongoing climate change, others benefit from it, for example, by showing range expansions. However, which specific features determine a species' vulnerability to climate change? Phenotypic plasticity, which has been described as the first line of defence against environmental change, may be of utmost importance here. Against this background, we here compare plasticity in stress tolerance in 3 copper butterfly species, which differ arguably in their vulnerability to climate change. Specifically, we investigated heat, cold and desiccation resistance after acclimatization to different temperatures in the adult stage. We demonstrate that acclimation at a higher temperature increased heat but decreased cold tolerance and desiccation resistance. Contrary to our predictions, species did not show pronounced variation in stress resistance, though plastic capacities in temperature stress resistance did vary across species. Overall, our results seemed to reflect population-rather than species-specific patterns. We conclude that the geographical origin of the populations used should be considered even in comparative studies. However, our results suggest that, in the 3 species studied here, vulnerability to climate change is not in the first place determined by stress resistance in the adult stage. As entomological studies focus all too often on adults only, we argue that more research effort should be dedicated to other developmental stages when trying to understand insect responses to environmental change. © 2017 Institute of Zoology, Chinese Academy of Sciences.

  12. New Screening Test Developed for the Blanching Resistance of Copper Alloys

    Science.gov (United States)

    Thomas-Ogbuji, Linus U.

    2004-01-01

    NASA's extensive efforts towards more efficient, safer, and more affordable space transportation include the development of new thrust-cell liner materials with improved capabilities and longer lives. For rocket engines fueled with liquid hydrogen, an important metric of liner performance is resistance to blanching, a phenomenon of localized wastage by cycles of oxidation-reduction due to local imbalance in the oxygen-fuel ratio. The current liner of the Space Shuttle Main Engine combustion chamber, a Cu-3Ag-0.5Zr alloy (NARloy-Z) is degraded in service by blanching. Heretofore, evaluating a liner material for blanching resistance involved elaborate and expensive hot-fire tests performed on rocket test stands. To simplify that evaluation, researchers at the NASA Glenn Research Center developed a screening test that uses simple, in situ oxidation-reduction cycling in a thermogravimetric analyzer (TGA). The principle behind this test is that resistance to oxidation or to the reduction of oxide, or both, implies resistance to blanching. Using this test as a preliminary tool to screen alloys for blanching resistance can improve reliability and save time and money. In this test a small polished coupon is hung in a TGA furnace at the desired (service) temperature. Oxidizing and reducing gases are introduced cyclically, in programmed amounts. Cycle durations are chosen by calibration, such that all copper oxides formed by oxidation are fully reduced in the next reduction interval. The sample weight is continuously acquired by the TGA as usual.

  13. A new disubstituted polyacetylene bearing 6-benzylaminopurine moieties: postfunctional synthetic strategy and sensitive chemosensor towards copper and cobalt ions.

    Science.gov (United States)

    Ou, Daxin; Zhang, Liang; Huang, Yanfen; Lou, Xiaoding; Qin, Jingui; Li, Zhen

    2013-05-14

    A new 6-benzylaminopurine-functionalized disubstituted polyacetylene (P2) with strong green fluorescence is successfully synthesized by utilizing the postfunctional method. The polymer is soluble in common organic solvents, and its strong green fluorescence can be quenched by copper and cobalt ions with a detection limit down to 1.0 × 10(-8) (0.64 ppb) and 3.3 × 10(-8) mol L(-1) (1.94 ppb), respectively. Moreover, not much interference is observed from other metal ions, including Li(+) , Na(+) , K(+) , Fe(3+) , Fe(2+) , Ni(2+) , Hg(2+) , Mg(2+) , Al(3+) , Zn(2+) , Mn(2+) , Pb(2+) , Ba(2+) , Ca(2+) , Cd(2+) , Ag(+) , and Cr(3+) . Furthermore, P2 can be put into application using test strips, making P2 a practical, sensitive, and selective copper and cobalt probe.

  14. Comparative time-courses of copper-ion-mediated protein and lipid oxidation in low-density lipoprotein

    DEFF Research Database (Denmark)

    Knott, Heather M; Baoutina, Anna; Davies, Michael Jonathan

    2002-01-01

    Free radicals damage both lipids and proteins and evidence has accumulated for the presence of both oxidised lipids and proteins in aged tissue samples as well as those from a variety of pathologies including atherosclerosis, diabetes, and Parkinson's disease. Oxidation of the protein and lipid...... moieties of low-density lipoprotein is of particular interest due to its potential role in the unregulated uptake of lipids and cholesterol by macrophages; this may contribute to the initial stage of foam cell formation in atherosclerosis. In the study reported here, we examined the comparative time......-courses of lipid and protein oxidation during copper-ion-mediated oxidation of low-density lipoprotein. We show that there is an early, lipid-mediated loss of 40-50% of the Trp residues of the apoB100 protein. There is no comparable loss over an identical period during the copper-ion-mediated oxidation of lipid...

  15. SBA-15 mesoporous silica free-standing thin films containing copper ions bounded via propyl phosphonate units - preparation and characterization

    Science.gov (United States)

    Laskowski, Lukasz; Laskowska, Magdalena; Jelonkiewicz, Jerzy; Dulski, Mateusz; Wojtyniak, Marcin; Fitta, Magdalena; Balanda, Maria

    2016-09-01

    The SBA-15 silica thin films containing copper ions anchored inside channels via propyl phosphonate groups are investigated. Such materials were prepared in the form of thin films, with hexagonally arranged pores, laying rectilinear to the substrate surface. However, in the case of our thin films, their free standing form allowed for additional research possibilities, that are not obtainable for typical thin films on a substrate. The structural properties of the samples were investigated by X-ray reflectometry, atomic force microscopy (AFM) and transmission electron microscopy (TEM). The molecular structure was examined by Raman spectroscopy supported by numerical simulations. Magnetic measurements (SQUID magnetometry and EPR spectroscopy) showed weak antiferromagnetic interactions between active units inside silica channels. Consequently, the pores arrangement was determined and the process of copper ions anchoring by propyl phosphonate groups was verified in unambiguous way. Moreover, the type of interactions between magnetic atoms was determined.

  16. Highly selective and sensitive determination of copper ion by two novel optical sensors

    Directory of Open Access Journals (Sweden)

    Mehrorang Ghaedi

    2017-05-01

    Full Text Available New optical sensors for the determination of copper ion by incorporation of 1,1′-(4-nitro-1,2-phenylenebis(azan-1-yl-1-ylidenebis(methan-1-yl-1-lidenedinaphthalen-2-ol(L1, 1,1′-2,2′-(1,2-phenylenebis(ethene-2,1-diyldinaphthalen-2-ol 1(L2, dibutylphthalate (DBP and sodium tetraphenylborate (Na-TPB to the plasticized polyvinyl chloride matrices were prepared. The tendency of both ionophores (L2 and L1 as chromoionophore was significantly enhanced by the addition of DBP to the membrane. The proposed sensors benefit from advantages such as high stability, reproducibility and relatively long lifetime, good selectivity for Cu2+ ion determination over a large number of alkali, alkaline earth, transition and heavy metal ions. At optimum values of membrane compositions and experimental conditions, both sensors’ response was linear over a concentration range of 7.98 × 10−6 to 1.31 × 10−4mol L−1 and 1.99 × 10−6 to 5.12 × 10−5 mol L−1 for L2 and L1, respectively. Sensor detection limit based on the definition that the concentration of the sample leads to a signal equal to the blank signal plus three times of its standard deviation was found to be 3.99 × 10−7 and 5.88 × 10−7 mol L−1 for L2 and L1, respectively. The response time of the optodes (defined as the time required reaching the 90% of the peak signal was found to be 5–8 min for L2 and 20–25 min for L1 based sensor. The proposed optical sensors were applied successfully for the determination of Cu2+ ion content in water samples.

  17. Biological Effects of Drug-Free Alginate Beads Cross-Linked by Copper Ions Prepared Using External Ionotropic Gelation.

    Science.gov (United States)

    Pavelková, M; Kubová, K; Vysloužil, J; Kejdušová, M; Vetchý, D; Celer, V; Molinková, D; Lobová, D; Pechová, A; Vysloužil, J; Kulich, P

    2016-08-08

    External ionotropic gelation offers a unique possibility to entrap multivalent ions in a polymer structure. The aim of this experimental study was to prepare new drug-free sodium alginate (ALG) particles cross-linked by Cu(2+) ions and to investigate their technological parameters (particle size, sphericity, surface topology, swelling capacity, copper content, release of Cu(2+) ions, mucoadhesivity) and biological activity (cytotoxicity and efficiency against the most common vaginal pathogens-Herpes simplex, Escherichia coli, Candida albicans) with respect to potential vaginal administration. Beads prepared from NaALG dispersions (3 or 4%) were cross-linked by Cu(2+) ions (0.5 or 1.0 M CuCl2) using external ionotropic gelation. Prepared mucoadhesive beads with particle size over 1000 μm exhibited sufficient sphericity (all ˃0.89) and copper content (214.8-249.07 g/kg), which increased with concentration of polymer and hardening solution. Dissolution behaviour was characterized by extended burst effect, followed by 2 h of copper release. The efficiency of all samples against the most common vaginal pathogens was observed at cytotoxic Cu(2+) concentrations. Anti-HSV activity was demonstrated at a Cu(2+) concentration of 546 mg/L. Antibacterial activity of beads (expressed as minimum inhibition concentration, MIC) was influenced mainly by the rate of Cu(2+) release which was controlled by the extent of swelling capacity. Lower MIC values were found for E. coli in comparison with C. albicans. Sample ALG-3_1.0 exhibited the fastest copper release and was proved to be the most effective against both bacteria. This could be a result of its lower polymer concentration in combination with smaller particle size and thus larger surface area.

  18. Copper and silver ion implantation of aluminium oxide-blasted titanium surfaces: proliferative response of osteoblasts and antibacterial effects.

    Science.gov (United States)

    Fiedler, Jörg; Kolitsch, Andreas; Kleffner, Bernhard; Henke, Dietmar; Stenger, Steffen; Brenner, Rolf E

    2011-09-01

    Implant infection still represents a major clinical problem in orthopedic surgery. We therefore tested the in vitro biocompatibility and antibacterial effects of copper (Cu)- and silver (Ag)-ion implantation. Discs of a commonly used titanium alloy (Ti6AlV4) with an aluminium oxide-blasted surface were treated by Cu- or Ag-ion implantation with different dosage regimen (ranging from 1e15-17 ions cm(-2) at energies of 2-20 keV). The samples were seeded with primary human osteoblasts and cell attachment and proliferation was analyzed by an MTT-assay. In comparison to the reference titanium alloy there was no difference in the number of attached viable cells after two days. After seven days the number of viable cells was increased for Cu with 1e17 ions cm(-2) at 2 and 5 keV, and for Ag with 1e16 ions cm(-2) at 5 keV while it was reduced for the highest amount of Ag deposition (1e17 ions cm(-2) at 20 keV). Antibacterial effects on S.aureus and E.coli were marginal for the studied dosages of Cu but clearly present for Ag with 1e16 ions cm(-2) at 2 and 5 keV and 1e17 ions cm(-2) at 20 keV. These results indicate that Ag-ion implantation may be a promising methodological approach for antibacterial functionalization of titanium implants.

  19. Combined effects of temperature and copper ion concentration on the superoxide dismutase activity inCrassostrea ariakensis

    Institute of Scientific and Technical Information of China (English)

    WANG Hui; YANG Hongshuai; LIU Jiahui; LI Yanhong; LIU Zhigang

    2016-01-01

    Superoxide dismutase (SOD) is a crucial antioxidant enzyme playing the first defense line in antioxidant pathways against reactive oxygen species in various organisms including marine invertebrates. There exist mainly two specific forms, Cu/Zn-SOD (SOD1) and Mn-SOD (SOD2), in eukaryotes. SODs are known to be concurrently modulated by a variety of environmental stressors. By using central composite experimental design and response surface method, the joint effects of water temperature (18–34°C) and copper ion concentration (0.1–1.5 mg/L) on the total SOD activity in the digestive gland ofCrassostrea ariakensis were studied. The results showed that the linear effect of temperature was highly significant (P0.05), while the quadratic effect of copper ion concentration was highly significant (P0.05); the effect of temperature was greater than that of copper ion concentration. The model equation of digestive gland SOD enzyme activity towards the two factors of interest was established, withR2 and predictiveR2 as high as 0.961 6 and 0.820 7, respectively, suggesting that the goodness-of-fit to experimental data be very satisfactory, and could be applied to prediction of digestive gland SOD activity in C. ariakensis under the conditions of the experiment. Our results would be conducive to addressing the health of aquatic animals and/or to detecting environmental problems by taking SOD as a potential bioindicator.

  20. Silica nanoparticles functionalized with polyamidoamine (PAMAM) dendrimers as platforms for photoluminescence (PL) sensing of copper and cyanide ions.

    Science.gov (United States)

    Gerrans, Kateryna; Luhrs, Alicia; Feider, Clara; Margerum, Lawrence D

    2016-05-15

    Functionalized nanoparticles for photoluminescence (PL) applications are a promising technology for biomedical imaging and as sensors for small molecules. This work presents a new method to modify silica nanoparticles (SNP) using the bifunctional linker 1,1'-carbonyldiimidazole (CDI) with a series of polyamidoamine (PAMAM) dendrimer molecules followed by grafting of fluorescein isothiocyanate (FITC) or rhodamine B isothiocyanate (RITC) to create platforms for photoluminescence (PL) sensors. A dendrimer size and charge-variable response to only copper(II) ions confirmed the prediction of a selective turn-off sensor via proximity quenching. Both dye density and Cu(2+) quenching efficiency peaked with SNP-dendrimer generation 4 (64 terminal amines). In addition, changing the terminal dendrimer arms to carboxylic acid end groups increased the copper quenching suggesting that more metal ion binding sites were created in close proximity to the dyes. Of the small anions tested for a turn-off sensor, only cyanide ion fully restored the PL when reaching a 2:1 CN(-):Cu(2+) ratio, while EDTA was not as effective at the same ratio. Therefore, dendrimer size and surface charge on the nanoparticles controlled the dye loading and copper quenching efficiency, while creating multiple binding sites for cyanide over other metal binding anions. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Copper Nanoparticle-Incorporated Carbon Fibers as Free-Standing Anodes for Lithium-Ion Batteries.

    Science.gov (United States)

    Han, Pan; Yuan, Tao; Yao, Long; Han, Zhuo; Yang, Junhe; Zheng, Shiyou

    2016-12-01

    Copper-incorporated carbon fibers (Cu/CF) as free-standing anodes for lithium-ion batteries are prepared by electrospinning technique following with calcination at 600, 700, and 800 °C. The structural properties of materials are characterized by X-ray diffraction (XRD), Raman, thermogravimetry (TGA), scanning electron microscopy (SEM), transmission electron microscope (TEM), and energy dispersive X-ray spectrometry (EDS). It is found that the Cu/CF composites have smooth, regular, and long fibrous morphologies with Cu nanoparticles uniformly dispersed in the carbon fibers. As free-standing anodes, the unique structural Cu/CF composites show stable and high reversible capacities, together with remarkable rate and cycling capabilities in Li-ion batteries. The Cu/CF calcined at 800 °C (Cu/CF-800) has the highest charge/discharge capacities, long-term stable cycling performance, and excellent rate performance; for instance, the Cu/CF-800 anode shows reversible charge/discharge capacities of around 800 mAh g(-1) at a current density of 100 mA g(-1) with stable cycling performance for more than 250 cycles; even when the current density increases to 2 A g(-1), the Cu/CF-800 anode can still deliver a capacity of 300 mAh g(-1). This excellent electrochemical performance is attributed to the special 1D structure of Cu/CF composites, the enhanced electrical conductivity, and more Li(+) active positions by Cu nanoinclusion.

  2. Di(2-ethylhexyl)phosphoric acid-coconut oil supported liquid membrane for the separation of copper ions from copper plating wastewater

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Permeation of Cu(II) from its aqueous solution through a supported liquid membrane (SLM) containing di(2-ethylhexyl)phosphoric acid (D2EHPA) carrier dissolved in coconut oil has been studied. The effects of Cu(II), pH (in feed), H2SO4 (stripping) and D2EHPA (in membrane) concentrations have been investigated. The stability of the D2EHPA-coconutoil has also been evaluated. High Cu(II) concentration in the feed leads to an increase in flux from 4.1 × 10-9 to 8.9 × 10-9 mol/(m2·s) within the Cu(II) concentration range 7.8×10-4-78.6×10-4 mol/L at pH of 4.0 in the feed and 12.4 × 10-4 mol/L D2EHPA in the membrane phase. Increase in H2SO4 concentration in strip solution leads to an increase in copper ions flux up to 0.25 mol/L H2SO4, providing a maximum flux of 7.4 × 10-9 mol/(m2·s). The optimum conditions for Cu(II) transport are, pH of feed 4.0, 0.25 mol/L H2SO4 in strip phase and 12.4 × 10-4 mol/L D2EHPA (membrane) in 0.5 (m pore size polytetrafluoroethylene (PTFE) membrane. It has been observed that Cu(II) flux across the membrane tends to increase with the concentration of copper ions. Application of the method developed to copper plating bath rinse solutions has been found to be successful in the recovery of Cu(II). rane. It

  3. Copper-ion-assisted self-assembly of silicate clays in rod- and disklike morphologies.

    Science.gov (United States)

    Tsai, Wei-Cheng; Lin, Jiang-Jen

    2010-06-15

    Self-assembled rodlike (0.3-2.5 microm in diameter and 5.3-31 microm in length) and disklike microstructures (1.8-10.6 microm in width and 0.1-1.0 microm in thickness) are uniquely present in amorphous clay aggregates. Clay units were prepared by intercalation of Na(+)-montmorillonite (Na(+)-MMT) with copper ions (Cu(2+)) and poly(oxypropylene)-amine salt (POP) in simultaneous or stepwise ionic exchange reactions. Differences in process control during incorporation of Cu(2+) and hydrophobic POP greatly affected the layer structure of the clay units (d spacing of 12-53 A) and consequently their amphiphilic dispersion properties. By controlling the dispersion in water and drying at 80 degrees C, highly ordered self-assembly structures were obtained, presumably as a result of self-piling of clay units in competing vertical and horizontal directions. In general, association with Cu(2+) yielded units with a disklike microstructure, in contrast to the rod-like structure obtained for POP-intercalated clay. The self-assembled structures were characterized using X-ray diffraction, UV adsorption, thermal gravimetric analysis, zeta potential, scanning electron microscopy, and energy-dispersive X-ray spectroscopy techniques. Control of the clay self-piling process provides a new synthetic route for the fabrication of bottom-up microstructures that are potentially useful for templates, sensors, and electronic devices.

  4. Role of zinc and copper ions in the pathogenetic mechanisms of Alzheimer's and Parkinson's diseases.

    Science.gov (United States)

    Stelmashook, E V; Isaev, N K; Genrikhs, E E; Amelkina, G A; Khaspekov, L G; Skrebitsky, V G; Illarioshkin, S N

    2014-05-01

    Disbalance of zinc (Zn2+) and copper (Cu2+) ions in the central nervous system is involved in the pathogenesis of numerous neurodegenerative disorders such as multisystem atrophy, amyotrophic lateral sclerosis, Creutzfeldt-Jakob disease, Wilson-Konovalov disease, Alzheimer's disease, and Parkinson's disease. Among these, Alzheimer's disease (AD) and Parkinson's disease (PD) are the most frequent age-related neurodegenerative pathologies with disorders in Zn2+ and Cu2+ homeostasis playing a pivotal role in the mechanisms of pathogenesis. In this review we generalized and systematized current literature data concerning this problem. The interactions of Zn2+ and Cu2+ with amyloid precursor protein (APP), β-amyloid (Abeta), tau-protein, metallothioneins, and GSK3β are considered, as well as the role of these interactions in the generation of free radicals in AD and PD. Analysis of the literature suggests that the main factors of AD and PD pathogenesis (oxidative stress, structural disorders and aggregation of proteins, mitochondrial dysfunction, energy deficiency) that initiate a cascade of events resulting finally in the dysfunction of neuronal networks are mediated by the disbalance of Zn2+ and Cu2+.

  5. Studies on the Interactions of Copper and Zinc Ions with β-Amyloid Peptides by a Surface Plasmon Resonance Biosensor

    Directory of Open Access Journals (Sweden)

    He Tian

    2012-09-01

    Full Text Available The aggregation of β-amyloid peptide (Aβ into fibrils plays an important role in the pathogenesis of Alzheimer’s disease (AD. Metal ions including copper and zinc are closely connected to the precipitation and toxicity of Aβ. In this study, a surface plasmon resonance (SPR biosensor was constructed to investigate the interactions between Aβ and metal ions. Aβ peptide was immobilized on the SPR chip surface through a preformed alkanethiol self-assembled monolayer (SAM. Our observations indicate that the immobilized Aβ undergoes a conformational change upon exposure to the metal ions. A difference in metal binding affinity between Aβ1–28 and Aβ1–42 was also detected. The results suggest that SPR is an effective method to characterize the interactions between Aβ and metal ions.

  6. Studies on the interactions of copper and zinc ions with β-amyloid peptides by a surface plasmon resonance biosensor.

    Science.gov (United States)

    Yao, Fujun; Zhang, Ruiping; Tian, He; Li, Xiangjun

    2012-01-01

    The aggregation of β-amyloid peptide (Aβ) into fibrils plays an important role in the pathogenesis of Alzheimer's disease (AD). Metal ions including copper and zinc are closely connected to the precipitation and toxicity of Aβ. In this study, a surface plasmon resonance (SPR) biosensor was constructed to investigate the interactions between Aβ and metal ions. Aβ peptide was immobilized on the SPR chip surface through a preformed alkanethiol self-assembled monolayer (SAM). Our observations indicate that the immobilized Aβ undergoes a conformational change upon exposure to the metal ions. A difference in metal binding affinity between Aβ(1-28) and Aβ(1-42) was also detected. The results suggest that SPR is an effective method to characterize the interactions between Aβ and metal ions.

  7. Preparation of 3D nanoporous copper-supported cuprous oxide for high-performance lithium ion battery anodes.

    Science.gov (United States)

    Liu, Dequan; Yang, Zhibo; Wang, Peng; Li, Fei; Wang, Desheng; He, Deyan

    2013-03-01

    Three-dimensional (3D) nanoporous architectures can provide efficient and rapid pathways for Li-ion and electron transport as well as short solid-state diffusion lengths in lithium ion batteries (LIBs). In this work, 3D nanoporous copper-supported cuprous oxide was successfully fabricated by low-cost selective etching of an electron-beam melted Cu(50)Al(50) alloy and subsequent in situ thermal oxidation. The architecture was used as an anode in lithium ion batteries. In the first cycle, the sample delivered an extremely high lithium storage capacity of about 2.35 mA h cm(-2). A high reversible capacity of 1.45 mA h cm(-2) was achieved after 120 cycles. This work develops a promising approach to building reliable 3D nanostructured electrodes for high-performance lithium ion batteries.

  8. Application of a metal ion-imprinted polymer based on salen-Cu complex to flow injection preconcentration and FAAS determination of copper.

    Science.gov (United States)

    Walas, Stanisław; Tobiasz, Anna; Gawin, Marta; Trzewik, Bartosz; Strojny, Marcin; Mrowiec, Halina

    2008-06-30

    A new Cu(II)-imprinted polymer (Cu-IIP) for preconcentration of copper by liquid-solid extraction via flow injection technique has been proposed. Cu-IIP was obtained by copolymerization of salen-Cu(II) complex with styrene and divinylbenzene using suspension polymerization technique. Granules fraction of 60-80 microm in diameter was used as a microcolumn packing. Cu(II) sorption was proved to be the most effective from solutions of pH 7, whereas similar elution effectiveness was observed when applying as eluents hydrochloric or nitric acid in the concentration range of 0.5-10% (v/v). The system exhibited good long-term stability and acid resistance. Batch sorbent capacity was found to be 0.11 mmol g(-1) of a dry polymer. Enrichment factor (EF) for 30 s loading time was 16. Preconcentration of Cu(II) and potentially interfering metal ions is strongly pH dependent. Examination of Cu(II) sorption in the presence of Pb(II), Cd(II), Zn(II) and Ag(I) showed significant influence of cadmium and zinc ions only and that was for the interferent concentrations above 0.5 mg L(-1) (Cu-IIP mass of ca. 35 mg). The interference effect was reduced with the sorbent mass increase. Fe(III) and Mn(II) ions, present in treated tap water in relatively high concentrations, did not interfere. Effective pH adjusting of the loaded solution in on-line mode, when applying diluted Clark-Lubs buffering solution, allowed accurate copper determination in tap water (compared to graphite furnace atomic absorption spectrometry, GFAAS) using standard addition or combination calibration method.

  9. Process for improving moisture resistance of epoxy resins by addition of chromium ions

    Science.gov (United States)

    St.clair, A. K.; Stoakley, D. M.; St.clair, T. L.; Singh, J. J. (Inventor)

    1985-01-01

    A process for improving the moisture resistance properties of epoxidized TGMDA and DGEBA resin system by chemically incorporating chromium ions is described. The addition of chromium ions is believed to prevent the absorption of water molecules.

  10. Copper oxide and zinc oxide nanomaterials act as inhibitors of multidrug resistance transport in sea urchin embryos: their role as chemosensitizers.

    Science.gov (United States)

    Wu, Bing; Torres-Duarte, Cristina; Cole, Bryan J; Cherr, Gary N

    2015-05-05

    The ability of engineered nanomaterials (NMs) to act as inhibitors of ATP-binding cassette (ABC) efflux transporters in embryos of white sea urchin (Lytechinus pictus) was studied. Nanocopper oxide (nano-CuO), nanozinc oxide (nano-ZnO), and their corresponding metal ions (CuSO4 and ZnSO4) were used as target chemicals. The results showed that nano-CuO, nano-ZnO, CuSO4, and ZnSO4, even at relatively low concentrations (0.5 ppm), significantly increased calcein-AM (CAM, an indicator of ABC transporter activity) accumulation in sea urchin embryos at different stages of development. Exposure to nano-CuO, a very low solubility NM, at increasing times after fertilization (>30 min) decreased CAM accumulation, but nano-ZnO (much more soluble NM) did not, indicating that metal ions could cross the hardened fertilization envelope, but not undissolved metal oxide NMs. Moreover, nontoxic levels (0.5 ppm) of nano-CuO and nano-ZnO significantly increased developmental toxicity of vinblastine (an established ABC transporter substrate) and functioned as chemosensitizers. The multidrug resistance associated protein (MRP, one of ABC transporters) inhibitor MK571 significantly increased copper concentrations in embryos, indicating ABC transporters are important in maintaining low intracellular copper levels. We show that low concentrations of nano-CuO and nano-ZnO can make embryos more susceptible to other contaminants, representing a potent amplification of nanomaterial-related developmental toxicity.

  11. Metalloselenonein, the selenium analogue of metallothionein: synthesis and characterization of its complex with copper ions.

    OpenAIRE

    Oikawa, T; Esaki, N; Tanaka, H.; Soda, K

    1991-01-01

    We used an automated peptide synthesizer to produce a peptide, metalloselenonein, that contains selenocysteine residues substituted for all cysteine residues in Neurospora crassa copper metallothionein. Metalloselenonein binds 3 mol of Cu(I) per mol. This adduct shows a broad absorption band between 230 and 400 nm and a fluorescence band at 395 nm, which can be attributed to copper-selenolate coordination. The circular dichroism spectrum of the copper-metalloselenonein complex shows a positiv...

  12. [Study on the orientation of liquid crystals presented on the glass substrates spin-coated and functionalized with copper ions].

    Science.gov (United States)

    Wang, Shiming; Xiong, Xingliang; Zhang, Yan; Li, Guang; Chen, Mengmeng

    2013-06-01

    A stable, uniform, easily implemented, LC-based chemical and biological sensor substrate for orientations of liquid crystals (LCs) for a long-term is urgently needed for medical applications of the sensors. We proposed a use of spin-coating of copper perchlorate (Cu(ClO4)2), with five different concentrations(0-100mmol/L), directly on glass slides for fabricating a layer of chemically-sensitive copper ions. Observing the transmitted light with a polarized microscope, we found the luminosity of the light propagated through sensors deposited with copper ions started to weaken gradually after a certain time. The higher was the concentration of copper ions covered on the glass substrates of the sensors, the faster the weakening occurred, and the less time was needed for transmitted light to turn completely dark. But there was no change in luminosity of the transmitted light for the sensors without Cu(ClO4)2 spin-coating even after stored at room temperature (25 degrees C) for a whole day. When the Cu(ClO4)2 deposited sensors were stored within a drying oven at room temperature (25 degrees C) for 2 months, it was found that there vas almost no change in luminosity of the transmitted lights. The results showed that all the thin films of LC on glass slides functionalized with Cu(ClO4)2 could keep homeotropic and stable orientation for a long time; the concentration of Cu (ClO4)2I has an influence on the orientation response speed of LC from planar to perpendicular orientation.

  13. Facile synthesis of oxidation-resistant copper nanowires toward solution-processable, flexible, foldable, and free-standing electrodes.

    Science.gov (United States)

    Yin, Zhenxing; Lee, Chaedong; Cho, Sanghun; Yoo, Jeeyoung; Piao, Yuanzhe; Kim, Youn Sang

    2014-12-29

    Oxidation-resistant copper nanowires (Cu NWs) are synthesized by a polyol reduction method. These Cu NWs show excellent oxidation resistance, good dispersibility, and have a low sintering temperature. A Cu NW-based flexible, foldable, and free-standing electrode is fabricated by filtration and a sintering process. The electrode also exhibits high electrical conductivity even bending, folding, and free-standing. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Ion implantation method for preparing polymers having oxygen erosion resistant surfaces

    Science.gov (United States)

    Lee, Eal H.; Mansur, Louis K.; Heatherly, Jr., Lee

    1995-01-01

    Hard surfaced polymers and the method for making them are generally described. Polymers are subjected to simultaneous multiple ion beam bombardment, that results in a hardening of the surface, improved wear resistance, and improved oxygen erosion resistance.

  15. Rolling Resistance and Mechanical Properties of Grinded Copper Surfaces Using Molecular Dynamics Simulation

    Science.gov (United States)

    Liang, Shih-Wei; Wang, Chih-Hao; Fang, Te-Hua

    2016-09-01

    Mechanical properties of copper (Cu) film under grinding process were accomplished by molecular dynamics simulation. A numerical calculation was carried out to understand the distributions of atomic and slip vector inside the Cu films. In this study, the roller rotation velocity, temperature, and roller rotation direction change are investigated to clarify their effect on the deformation mechanism. The simulation results showed that the destruction of materials was increased proportionally to the roller rotation velocity. The machining process at higher temperature results in larger kinetic energy of atoms than lower temperature during the grinding process of the Cu films. The result also shows that the roller rotation in the counterclockwise direction had the better stability than the roller rotation in the clockwise direction due to significantly increased backfill atoms in the groove of the Cu film surface. Additionally, the effects of the rolling resistances on the Cu film surfaces during the grinding process are studied by the molecular dynamics simulation method.

  16. Rolling Resistance and Mechanical Properties of Grinded Copper Surfaces Using Molecular Dynamics Simulation.

    Science.gov (United States)

    Liang, Shih-Wei; Wang, Chih-Hao; Fang, Te-Hua

    2016-12-01

    Mechanical properties of copper (Cu) film under grinding process were accomplished by molecular dynamics simulation. A numerical calculation was carried out to understand the distributions of atomic and slip vector inside the Cu films. In this study, the roller rotation velocity, temperature, and roller rotation direction change are investigated to clarify their effect on the deformation mechanism. The simulation results showed that the destruction of materials was increased proportionally to the roller rotation velocity. The machining process at higher temperature results in larger kinetic energy of atoms than lower temperature during the grinding process of the Cu films. The result also shows that the roller rotation in the counterclockwise direction had the better stability than the roller rotation in the clockwise direction due to significantly increased backfill atoms in the groove of the Cu film surface. Additionally, the effects of the rolling resistances on the Cu film surfaces during the grinding process are studied by the molecular dynamics simulation method.

  17. An Optical Fiber-Based Sensor Array for the Monitoring of Zinc and Copper Ions in Aqueous Environments

    Directory of Open Access Journals (Sweden)

    Steven Kopitzke

    2014-02-01

    Full Text Available Copper and zinc are elements commonly used in industrial applications as aqueous solutions. Before the solutions can be discharged into civil or native waterways, waste treatment processes must be undertaken to ensure compliance with government guidelines restricting the concentration of ions discharged in solution. While currently there are methods of analysis available to monitor these solutions, each method has disadvantages, be it high costs, inaccuracy, and/or being time-consuming. In this work, a new optical fiber-based platform capable of providing fast and accurate results when performing solution analysis for these metals is described. Fluorescent compounds that exhibit a high sensitivity and selectivity for either zinc or copper have been employed for fabricating the sensors. These sensors demonstrated sub-part-per-million detection limits, 30-second response times, and the ability to analyze samples with an average error of under 10%. The inclusion of a fluorescent compound as a reference material to compensate for fluctuations from pulsed excitation sources has further increased the reliability and accuracy of each sensor. Finally, after developing sensors capable of monitoring zinc and copper individually, these sensors are combined to form a single optical fiber sensor array capable of simultaneously monitoring concentration changes in zinc and copper in aqueous environments.

  18. A new approach to copper ion removal from water by polymeric nanocomposite membrane embedded with γ-alumina nanoparticles

    Science.gov (United States)

    Ghaemi, Negin

    2016-02-01

    The ability of alumina (Al2O3) nanoparticles in adsorption of heavy metals was employed in improving the copper removal efficiency of PES membranes. Mixed matrix membranes were prepared using PES and different amounts of alumina nanoparticles by phase inversion method. The fabricated membranes were characterized in terms of morphology and performance using scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses, water contact angle and porosity measurements, determination of pure water flux, copper ion removal, and reusability test. Mixed matrix membranes revealed higher water permeation compared with the pristine PES membrane just by adding small amounts of nanoparticles (≤ 1.0 wt. %) as a result of increasing the membrane porosity and hydrophilicity after addition of alumina nanoparticles into the membrane matrix. Moreover, copper ion removal efficiency of alumina mixed membranes was improved. Membrane performance tests as well as adsorptive nature of alumina nanoparticles proposed that adsorption was the most possible separation mechanism by mixed matrix membranes. Reusability test of membrane confirmed the durability of removal efficiency even after four cycles of filtration.

  19. In vitro efficacy of copper and silver ions in eradicating Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Acinetobacter baumannii: implications for on-site disinfection for hospital infection control.

    Science.gov (United States)

    Huang, Hsin-I; Shih, Hsiu-Yun; Lee, Chien-Ming; Yang, Thomas C; Lay, Jiunn-Jyi; Lin, Yusen E

    2008-01-01

    Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Acinetobacter baumannii are major opportunistic waterborne pathogens causing hospital-acquired infections. Copper-silver ionization has been shown to be effective in controlling Legionella colonization in hospital water systems. The objective was to determine the efficacy of copper and silver ions alone and in combination in eradicating P. aeruginosa, S. maltophilia and A. baumannii at the concentration applied to Legionella control. Kill curve experiments and mathematical modeling were conducted at copper and silver ion concentrations of 0.1, 0.2, 0.4, 0.8 and 0.01, 0.02, 0.04, 0.08 mg/L, respectively. The combinations of copper and silver ions were tested at concentrations of 0.2/0.02 and 0.4/0.04 mg/L, respectively. Initial organism concentration was ca. of 3 x 10(6)cfu/mL, and viability of the test organisms was assessed at predetermined time intervals. Samples (0.1 mL) withdrawn were mixed with 10 microL neutralizer solution immediately, serially diluted and plated in duplicate onto blood agar plates. The culture plates were incubated for 48 h at 37 degrees C and enumerated for the cfu (detection limit 10 cfu/mL). The results showed all copper ion concentrations tested (0.1-0.8 mg/L) achieved more than 99.999% reduction of P. aeruginosa which appears to be more susceptible to copper ions than S. maltophilia and A. baumannii. Silver ions concentration of 0.08 mg/L achieved more than 99.999% reduction of P. aeruginosa, S. maltophilia and A. baumannii in 6, 12 and 96 h, respectively. Combination of copper and silver ions exhibited a synergistic effect against P. aeruginosa and A. baumannii while the combination exhibited an antagonistic effect against S. maltophilia. Ionization may have a potential to eradicate P. aeruginosa, S. maltophilia and A. baumannii from hospital water systems.

  20. Catalytic therapy of cancer by ascorbic acid involves redox cycling of exogenous/endogenous copper ions and generation of reactive oxygen species.

    Science.gov (United States)

    Hadi, S M; Ullah, M F; Shamim, U; Bhatt, S H; Azmi, A S

    2010-01-01

    Catalytic therapy is a cancer treatment modality based on the generation of reactive oxygen species (ROS) through administration of ascorbate/medicinal herbal extracts and copper. It is known that antioxidants such as ascorbate also exhibit prooxidant activity in the presence of transition metals such as copper. Based on our work and that in the literature, in this review we propose a mechanism for the cytotoxic action of ascorbate against cancer cells. It involves redox cycling of exogenous/endogenous copper ions and the consequent generation of ROS leading to oxidative DNA breakage. Using human peripheral lymphocytes and the Comet assay, we have shown that ascorbic acid is able to cause oxidative breakage in cellular DNA. Such DNA degradation is inhibited by neocuproine (a Cu(I) sequestering agent) and scavengers of ROS indicating that the cellular DNA breakage involves the generation of Cu(I) and formation of ROS. Similar results are also obtained with plant polyphenol antioxidants that are important constituents of medicinal herbal extracts. Copper is an essential component of chromatin and can take part in redox reactions. It is well established that tissue, cellular and serum copper levels are considerably elevated in various malignancies. Therefore, cancer cells may be more subject to electron transfer between copper ions and ascorbate/plant polyphenols to generate ROS. In this review we cite evidence to indicate that in catalytic therapy cytotoxic action against cancer cells involves redox cycling of exogenous/endogenous copper ions.

  1. EVALUATION OF APPLICATION OF COAGULANTS CONTAINING DIVALENT AND TRIVALENT IRON TO ENHANCE REMOVAL OF ORGANIC COMPOUNDS AND COMPLEXED COPPER AND TIN IONS FROM INDUSTRIAL EFFLUENTS

    Directory of Open Access Journals (Sweden)

    Maciej Thomas

    2014-10-01

    Full Text Available The article presents the issues concerning physical and chemical parameters of raw sewage from the production of printed circuit boards and the composition of the bath used technology in terms of meeting the requirements for the introduction of treated wastewater into surface waters, ground or the municipal sewage system. Showed test results for the removal of organic compounds and ions complexed copper (II and tin (II and (IV using coagulants containing ions of Fe (II and Fe (III. The studies showed the high efficiency of removal of organic compounds and tin compounds. Explained the possible causes of the difficulties of precipitation complexed copper ions (II.

  2. Redox active copper chelate overcomes multidrug resistance in T-lymphoblastic leukemia cell by triggering apoptosis.

    Science.gov (United States)

    Ganguly, Avishek; Basu, Soumya; Banerjee, Kaushik; Chakraborty, Paramita; Sarkar, Avijit; Chatterjee, Mitali; Chaudhuri, Soumitra Kumar

    2011-05-01

    Multidrug resistance (MDR) mediated by the over expression of drug efflux protein P-glycoprotein (P-gp) is one of the major impediments to successful treatment of cancer. P-gp acts as an energy-dependent drug efflux pump and reduces the intracellular concentration of structurally unrelated drugs inside the cells. Therefore, there is an urgent need for development of new molecules that are less toxic to normal cell and preferentially effective against drug resistant malignant cells. In this preclinical study we report the apoptotic potential of copper N-(2-hydroxyacetophenone) glycinate (CuNG) on doxorubicin resistant T lymphoblastic leukaemia cells (CEM/ADR5000). To evaluate the cytotoxic effect of CuNG, we used different normal cell lines (NIH 3T3, Chang liver and human PBMC) and cancerous cell lines (CEM/ADR5000, parental sensitive CCRF-CEM, SiHa and 3LL) and conclude that CuNG preferentially kills cancerous cells, especially both leukemic cell types irrespective of their MDR status, while leaving normal cell totally unaffected. Moreover, CuNG involves reactive oxygen species (ROS) for induction of apoptosis in CEM/ADR5000 cells through the intrinsic apoptotic pathway. This is substantiated by our observation that antioxidant N-acetyle-cysteine (NAC) and PEG catalase could completely block ROS generation and, subsequently, abrogates CuNG induced apoptosis. On the other hand, uncomplexed ligand N-(2-hydroxyacetophenone) glycinate (NG) fails to generate a significant amount of ROS and concomitant induction of apoptosis in CEM/ADR5000 cells. Therefore, CuNG induces drug resistant leukemia cells to undergo apoptosis and proves to be a molecule having therapeutic potential to overcome MDR in cancer.

  3. Biosorption of copper ions from aqueous solutions by Spirulina platensis biomass

    Directory of Open Access Journals (Sweden)

    Ali A. Al-Homaidan

    2014-01-01

    Full Text Available In this study, the economically important micro-alga (cyanobacterium Spirulina platensis was used as biosorbent for the removal of copper from aqueous solutions. The cyanobacterium was exposed to various concentrations of copper and adsorption of copper by the biomass was evaluated under different conditions that included pH, contact time, temperature, concentration of adsorbate and the concentration of dry biomass. Increased adsorption of copper by the non-living biomass was recorded with gradually increasing pH, and a maximal uptake by the biomass was observed at pH 7. The adsorption of copper was found to increase gradually along with decrease in biomass concentration. Biosorption was found to be at a maximum (90.6%, in a solution containing 100 mg copper/L, at pH 7, with 0.050 g dry biomass and at 37 °C with 90 min of contact time. Analysis of the spectrum obtained with atomic absorption spectrophotometer (AAS, indicated that the adsorbent has a great potential to remove copper from aqueous media contributing to an eco-friendly technology for efficient bioremediation in the natural environment.

  4. Metalloselenonein, the selenium analogue of metallothionein: synthesis and characterization of its complex with copper ions.

    Science.gov (United States)

    Oikawa, T; Esaki, N; Tanaka, H; Soda, K

    1991-01-01

    We used an automated peptide synthesizer to produce a peptide, metalloselenonein, that contains selenocysteine residues substituted for all cysteine residues in Neurospora crassa copper metallothionein. Metalloselenonein binds 3 mol of Cu(I) per mol. This adduct shows a broad absorption band between 230 and 400 nm and a fluorescence band at 395 nm, which can be attributed to copper-selenolate coordination. The circular dichroism spectrum of the copper-metalloselenonein complex shows a positive band around 245 nm attributable to asymmetry in metal coordination. PMID:1826562

  5. Ion release from copper phosphate cement and influence on Streptococcus mutans growth in vitro: a comparative study.

    Science.gov (United States)

    Foley, Jennifer; Blackwell, Alison

    2003-01-01

    The aim of this study was to compare the effects of a black copper cement (BCC), an established restorative material (a conventional glass ionomer cement) and two temporary restorative materials (a zinc phosphate and a zinc polycarboxylate cement) on the growth of Streptococcus mutans in vitro, and to correlate bacterial growth with ion release from each material. Test specimens were eluted in either 0.1 M lactic acid, pH 4, or 0.1 M sodium chloride, pH 7. At 2 days, 7 days, 28 days and 6 months, eluates were inoculated with S. mutans and bacterial growth was recorded. Metal ion (Cu(2+), Zn(2+ )and Mg(2+)) and fluoride release were measured. At most immersion times, the different materials had a statistically significant inhibitory effect on bacterial growth compared to the respective control, at both pH levels. The inhibitory effect decreased with time and in most cases was associated with high levels of ion release at the beginning of the experimental period, followed by significantly lower levels. For BCC, there were statistically significant relationships between the median rates of growth of S. mutans in the presence of BCC eluates and the median values for release of copper and zinc, although not magnesium. Of the different materials, BCC demonstrated greatest antibacterial activity.

  6. Acid-base characterization, coordination properties towards copper(II) ions and DNA interaction studies of ribavirin, an antiviral drug.

    Science.gov (United States)

    Nagaj, Justyna; Starosta, Radosław; Jeżowska-Bojczuk, Małgorzata

    2015-01-01

    We have studied processes of copper(II) ion binding by ribavirin, an antiviral agent used in treating hepatitis C, which is accompanied usually by an increased copper level in the serum and liver tissue. Protonation equilibria and Cu(II) binding were investigated using the UV-visible, EPR and NMR spectroscopic techniques as well as the DFT (density functional theory) calculations. The spectroscopic data suggest that the first complex is formed in the water solution at pH as low as 0.5. In this compound Cu(II) ion is bound to one of the nitrogen atoms from the triazole ring. Above pH6.0, the metal ion is surrounded by two nitrogen and two oxygen atoms from two ligand molecules. The DFT calculations allowed to determine the exact structure of this complex. We found that in the lowest energy isomer two molecules of the ligand coordinate via O and N4 atoms in trans positions. The hypothetical oxidative properties of the investigated system were also examined. It proved not to generate plasmid DNA scission products. However, the calf thymus (CT)-DNA binding studies showed that it reacts with ribavirin and its cupric complex. Moreover, the interaction with the complex is much more efficient.

  7. Aminobenzenesulfonamide functionalized SBA-15 nanoporous molecular sieve: A new and promising adsorbent for preconcentration of lead and copper ions

    Institute of Scientific and Technical Information of China (English)

    Leila Hajiaghababaei; Babak Ghasemi; Alireza Badiei; Hassan Goldooz; Mohammad Reza Ganjali; Ghodsi Mohammadi Ziarani

    2012-01-01

    A rapid method for the extraction and monitoring of nanogram level of Pb2+ and Cu2+ ions using uniform silanized mesopor (SBA-15) functionalized with aminobenzenesulfonamide groups and flame atomic absorption spectrometry (FAAS) is presented.Aminobenzenesulfonamide functionalized SBA-15 was synthesized according to procedure in the literature and the presence of organic groups in the silica framework was demonstrated by FT-IR spectra.The functionalized product showed the BET surface area 110 m2/g and pore diameter 5.1 nm,based on adsorption-desorption of N2 at 77 K.The effect of several variables such as (amount of adsorbent,stirring time,pH and presence of other ions in the medium) has been studied.Lead and copper were completely extracted at pH greater than 3 after stirring for 10 min.The maximum capacity of the adsorbent was found to be 191.3 ± 1.4 and 155.0 ± 1.0 μg of lead and copper ions/mg functionalized SBA-15,respectively.The preconcentration factor of the method was found to be 200.The detection limit of the technique was 3.4 and 0.4 ng/mL for Pb2+ and Cu2+,respectively.The applications of this methodology for real samples were examined by various water type,black tea and pepper samples.

  8. Characteristics of copper removal and ion release during copper biosorption by Stenotrophomonas maltophilia in presence of benzo[a]pyrene

    Institute of Scientific and Technical Information of China (English)

    田云; 叶锦韶; 尹华; 彭辉; 李取生; 白洁琼; 谢丹平

    2013-01-01

    The ability of Stenotrophomonas maltophilia was demonstrated to selectively remove Cu2+from Cu(NO3)2 solution under the circumstance that 1 mg/L benzo[a]pyrene(BaP) was either present or not. The removal ratios of 2 and 10 mg/L Cu2+by 0.25 g/L biosorbent are up to 80% and 49% at 10 min, respectively. The biosorption includes ion exchange, NO3 reduction, ion release, and cell oxidation by Cu2+. BaP does not significantly affect Cu2+removal and ion release. Although 2 mg/L Cu2+increases the release of PO4 3, K+, NH4 +and Ca2+, 10 mg/L Cu2+has strong oxidation on cell, and then decreases NO3 reduction and hinders the release of K+, NH4 +and Ca2+. Exogenous cations inhibit the Cu2+biosorption, while additional anions increase the removal ratios of 10 mg/L Cu2+from 52% to 88%.

  9. Sorption of diuron, atrazine, and copper ion on chars with long-term natural oxidation in soils

    Science.gov (United States)

    Cheng, C.; Lin, T.; Lai, C.

    2011-12-01

    Biochar has been proposed as a measure to sequestrate carbon (C) and to increase soil fertility in sustainable agriculture. However, its sorption characteristics to herbicides, such as lowing herbicides efficacy, may constrain its agricultural application. This assertion may be arguable because most studies so far were conducted with the newly produced char and barely considered the "ageing effect" of old char since it could be oxidized over long time. In this study, historical char samples were collected and compared with the newly produced char. Batch sorption studies of diuron, atrazine, and copper ion onto chars was performed. Greater sorption of Cu was observed on the historical char samples and reached a saturated sorption at 30 mg g-1 for Cu, much higher adsorption value than newly produced char at 4 mg g-1. In contrast, sorption of diuron and atrazine on newly produced char had the highest sorption capacity than the historical char samples. The historical chars also had much higher negative charge than the newly produced char, but its surface area were lower than the new char. The results indicated that change in surface functional groups through natural oxidation rather than the change of surface area may have more pronounced influences on sorption characteristics, in which the negative charge on the historical chars' surface could hinder the adsorption of diuron and atrazine while enhance the sorption to copper ion. Biological assay to test the toxicity of diuron and copper ion for both historical and new chars on rye seed were conducted and will be presented in our poster.

  10. Correlation models between environmental factors and bacterial resistance to antimony and copper.

    Directory of Open Access Journals (Sweden)

    Zunji Shi

    Full Text Available Antimony (Sb and copper (Cu are toxic heavy metals that are associated with a wide variety of minerals. Sb(III-oxidizing bacteria that convert the toxic Sb(III to the less toxic Sb(V are potentially useful for environmental Sb bioremediation. A total of 125 culturable Sb(III/Cu(II-resistant bacteria from 11 different types of mining soils were isolated. Four strains identified as Arthrobacter, Acinetobacter and Janibacter exhibited notably high minimum inhibitory concentrations (MICs for Sb(III (>10 mM,making them the most highly Sb(III-resistant bacteria to date. Thirty-six strains were able to oxidize Sb(III, including Pseudomonas-, Comamonas-, Acinetobacter-, Sphingopyxis-, Paracoccus- Aminobacter-, Arthrobacter-, Bacillus-, Janibacter- and Variovorax-like isolates. Canonical correspondence analysis (CCA revealed that the soil concentrations of Sb and Cu were the most obvious environmental factors affecting the culturable bacterial population structures. Stepwise linear regression was used to create two predictive models for the correlation between soil characteristics and the bacterial Sb(III or Cu(II resistance. The concentrations of Sb and Cu in the soil was the significant factors affecting the bacterial Sb(III resistance, whereas the concentrations of S and P in the soil greatly affected the bacterial Cu(II resistance. The two stepwise linear regression models that we derived are as follows: MIC(Sb(III=606.605+0.14533 x C(Sb+0.4128 x C(Cu and MIC((Cu(II=58.3844+0.02119 x C(S+0.00199 x CP [where the MIC(Sb(III and MIC(Cu(II represent the average bacterial MIC for the metal of each soil (μM, and the C(Sb, C(Cu, C(S and C(P represent concentrations for Sb, Cu, S and P (mg/kg in soil, respectively, p<0.01]. The stepwise linear regression models we developed suggest that metals as well as other soil physicochemical parameters can contribute to bacterial resistance to metals.

  11. Studies on Zinc and Copper Ion in Relation to Wound Healing in ...

    African Journals Online (AJOL)

    olayemitoyin

    of both male and female goats could also be a factor for wound healing in the animals. Keywords: Wound ... and healing of wounds. The direct role of copper in facilitating angiogenesis .... well as activities of fibroblasts and skin immune cells.

  12. Manganese-II oxidation and Copper-II resistance in endospore forming Firmicutes isolated from uncontaminated environmental sites

    Directory of Open Access Journals (Sweden)

    Cristina Dorador

    2016-04-01

    Full Text Available The accumulation of metals in natural environments is a growing concern of modern societies since they constitute persistent, non-degradable contaminants. Microorganisms are involved in redox processes and participate to the biogeochemical cycling of metals. Some endospore-forming Firmicutes (EFF are known to oxidize and reduce specific metals and have been isolated from metal-contaminated sites. However, whether EFF isolated from uncontaminated sites have the same capabilities has not been thoroughly studied. In this study, we measured manganese oxidation and copper resistance of aerobic EFF from uncontaminated sites. For the purposes of this study we have sampled 22 natural habitats and isolated 109 EFF strains. Manganese oxidation and copper resistance were evaluated by growth tests as well as by molecular biology. Overall, manganese oxidation and tolerance to over 2 mM copper was widespread among the isolates (more than 44% of the isolates exhibited Mn (II-oxidizing activity through visible Birnessite formation and 9.1% tolerate over 2 mM copper. The co-occurrence of these properties in the isolates was also studied. Manganese oxidation and tolerance to copper were not consistently found among phylogenetically related isolates. Additional analysis correlating the physicochemical parameters measured on the sampling sites and the metabolic capabilities of the isolates showed a positive correlation between in situ alkaline conditions and the ability of the strains to perform manganese oxidation. Likewise, a negative correlation between temperature in the habitat and copper tolerance of the strains was observed. Our results lead to the conclusion that metal tolerance is a wide spread phenomenon in unrelated aerobic EFF from natural uncontaminated environments.

  13. Complete Genome Sequences of Six Copper-Resistant Xanthomonas citri pv.?citri Strains Causing Asiatic Citrus Canker, Obtained Using Long-Read Technology

    OpenAIRE

    Richard, Damien; Boyer, Claudine; Vernière, Christian; Canteros, B.I.; Lefeuvre, Pierre; Pruvost, Olivier

    2017-01-01

    The gammaproteobacterium Xanthomonas citri pv. citri causes Asiatic citrus canker. Pathotype A strains have a broad host range, which includes most commercial citrus species, and they cause important economic losses worldwide. Control often relies on frequent copper sprays. We present here the complete genomes of six X. citri pv. citri copper-resistant strains. (Résumé d'auteur)

  14. Complete Genome Sequences of Six Copper-Resistant Xanthomonas citri pv. citri Strains Causing Asiatic Citrus Canker, Obtained Using Long-Read Technology

    Science.gov (United States)

    Richard, Damien; Boyer, Claudine; Vernière, Christian; Canteros, Blanca I.; Lefeuvre, Pierre

    2017-01-01

    ABSTRACT The gammaproteobacterium Xanthomonas citri pv. citri causes Asiatic citrus canker. Pathotype A strains have a broad host range, which includes most commercial citrus species, and they cause important economic losses worldwide. Control often relies on frequent copper sprays. We present here the complete genomes of six X. citri pv. citri copper-resistant strains. PMID:28336584

  15. Analytical application of solid contact ion-selective electrodes for determination of copper and nitrate in various food products and drinking water.

    Science.gov (United States)

    Wardak, Cecylia; Grabarczyk, Malgorzata

    2016-08-02

    A simple, fast and cheap method for monitoring copper and nitrate in drinking water and food products using newly developed solid contact ion-selective electrodes is proposed. Determination of copper and nitrate was performed by application of multiple standard additions technique. The reliability of the obtained results was assessed by comparing them using the anodic stripping voltammetry or spectrophotometry for the same samples. In each case, satisfactory agreement of the results was obtained, which confirms the analytical usefulness of the constructed electrodes.

  16. Static secondary ion mass spectrometry investigation of corrosion inhibitor Irgamet®39 on copper surfaces treated in power transformer insulating oil

    OpenAIRE

    Facciotti, Marco; Amaro, Pedro S.; Brown, Richard C. D.; Paul L. Lewin; Pilgrim, James A.; Wilson, Gordon; Jarman, Paul N.; Fletcher, Ian W.

    2015-01-01

    Static secondary ion mass spectrometry was used to study the corrosion inhibitor Irgamet®39 on the surface of copper treated in insulating oils and the effect of temperature changes, by means of temperature programmed desorption experiments under vacuum, on metal coverage. Four commercial oils, both corrosive and non-corrosive, showed no significant influence on the stability of the tolyltriazole layer and the energy of its main desorption event from copper was calculated around 100 kJ mol?1....

  17. Role of copper oxides in contact killing of bacteria.

    Science.gov (United States)

    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.

  18. Electrical Resistivity, Tribological Behaviour of Multiwalled Carbon Nanotubes and Nanoboron Carbide Particles Reinforced Copper Hybrid Composites for Pantograph Application

    Directory of Open Access Journals (Sweden)

    N. Selvakumar

    2016-01-01

    Full Text Available This work focuses on the influence and contribution of multiwalled carbon-nanotube (MWCNT–boron carbide (B4C to the mechanical and tribological properties of copper matrix composites. Different weight fractions of nano- B4C-containing fixed-weight fractions of MWCNT-reinforced copper composites were prepared using the entrenched cold-press sintering method of powder metallurgy. The wear losses of sintered Cu–MWCNT–B4C composites were investigated by conducting sliding tests in a pin-on-disc apparatus. The addition of reinforcements showed enhancements in the hardness and wear properties of the composites due to the uniform dispersion of the secondary reinforcement in the copper matrix and the self-lubricating effect of the MWCNTs. The effects of the nanoparticle distribution in the matrix, the worn surface morphology, and the elemental composition of the composites were characterized using high-resolution scanning electron microscopy and X-ray diffraction analysis. The electrical resistivity of the fabricated copper hybrid composite preforms was evaluated using a four-point probe tester. Our results highlight the use of experiential reinforcing limits of B4C on the wear and electrical and mechanical behaviour of copper composites.

  19. Biodynamics of copper oxide nanoparticles and copper ions in an oligochaete - Part II: Subcellular distribution following sediment exposure

    Science.gov (United States)

    Thit, Amalie; Ramskov, Tina; Croteau, Marie-Noele; Selck, Henriette

    2016-01-01

    The use and likely incidental release of metal nanoparticles (NPs) is steadily increasing. Despite the increasing amount of published literature on metal NP toxicity in the aquatic environment, very little is known about the biological fate of NPs after sediment exposures. Here, we compare the bioavailability and subcellular distribution of copper oxide (CuO) NPs and aqueous Cu (Cu-Aq) in the sediment-dwelling worm Lumbriculus variegatus. Ten days (d) sediment exposure resulted in marginal Cu bioaccumulation in L. variegatus for both forms of Cu. Bioaccumulation was detected because isotopically enriched 65Cu was used as a tracer. Neither burrowing behavior or survival was affected by the exposure. Once incorporated into tissue, Cu loss was negligible over 10 d of elimination in clean sediment (Cu elimination rate constants were not different from zero). With the exception of day 10, differences in bioaccumulation and subcellular distribution between Cu forms were either not detectable or marginal. After 10 d of exposure to Cu-Aq, the accumulated Cu was primarily partitioned in the subcellular fraction containing metallothionein-like proteins (MTLP, ≈40%) and cellular debris (CD, ≈30%). Cu concentrations in these fractions were significantly higher than in controls. For worms exposed to CuO NPs for 10 d, most of the accumulated Cu was partitioned in the CD fraction (≈40%), which was the only subcellular fraction where the Cu concentration was significantly higher than for the control group. Our results indicate that L. variegatus handle the two Cu forms differently. However, longer-term exposures are suggested in order to clearly highlight differences in the subcellular distribution of these two Cu forms.

  20. Structural Studies of the Alzheimer's Amyloid Precursor Protein Copper-Binding Domain Reveal How It Binds Copper Ions

    Energy Technology Data Exchange (ETDEWEB)

    Kong, G.K.-W.; Adams, J.J.; Harris, H.H.; Boas, J.F.; Curtain, C.C.; Galatis, D.; Master, C.L.; Barnham, K.J.; McKinstry, W.J.; Cappai, R.; Parker, M.W.; /Sydney U.

    2007-07-09

    Alzheimer's disease (AD) is the major cause of dementia. Amyloid {beta} peptide (A {beta}), generated by proteolytic cleavage of the amyloid precursor protein (APP), is central to AD pathogenesis. APP can function as a metalloprotein and modulate copper (Cu) transport, presumably via its extracellular Cu-binding domain (CuBD). Cu binding to the CuBD reduces A{beta} levels, suggesting that a Cu mimetic may have therapeutic potential. We describe here the atomic structures of apo CuBD from three crystal forms and found they have identical Cu-binding sites despite the different crystal lattices. The structure of Cu[2+]-bound CuBD reveals that the metal ligands are His147, His151, Tyrl68 and two water molecules, which are arranged in a square pyramidal geometry. The site resembles a Type 2 non-blue Cu center and is supported by electron paramagnetic resonance and extended X-ray absorption fine structure studies. A previous study suggested that Met170 might be a ligand but we suggest that this residue plays a critical role as an electron donor in CuBDs ability to reduce Cu ions. The structure of Cu[+]-bound CuBD is almost identical to the Cu[2+]-bound structure except for the loss of one of the water ligands. The geometry of the site is unfavorable for Cu[+], thus providing a mechanism by which CuBD could readily transfer Cu ions to other proteins.

  1. Experimental and numerical optical characterization of plasmonic copper nanoparticles embedded in ZnO fabricated by ion implantation and annealing

    Energy Technology Data Exchange (ETDEWEB)

    Le, Khai Q. [Faculty of Science and Technology, Hoa Sen University, Ho Chi Minh City (Viet Nam); Department of Physics, Faculty of Science, Jazan University, P.O. Box 114, 45142 Jazan (Saudi Arabia); Nguyen, Hieu P.T. [Department of Electrical and Computer Engineering, New Jersey Institute of Technology, NJ 07102 (United States); Ngo, Quang Minh [Institute of Material Sciences, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay, Hanoi (Viet Nam); Canimoglu, Adil [Nigde University, Faculty of Arts and Sciences, Physics Department, Nigde (Turkey); Can, Nurdogan, E-mail: cannurdogan@yahoo.com [Celal Bayar University, Faculty of Arts and Sciences, Department of Physics, Muradiye, Manisa (Turkey); Department of Physics, Faculty of Science, Jazan University, P.O. Box 114, 45142 Jazan (Saudi Arabia)

    2016-06-05

    Here we describe the successfully fabrication of metal nanoparticle crystals by implanting copper (Cu) ions into single zinc oxide (ZnO) crystals with ion energy of 400 keV at ion doses of 1 × 10{sup 16} to 1 × 10{sup 17} ions/cm{sup 2}. After implantation and post-annealing treatment, the Cu implanted ZnO produces a broad range of luminescence emissions, ranging from green to yellow. A green luminescence peak at 550 nm could be ascribed to the isolated Cu ions. The changes in luminescence emission bands between the initial implant and annealed suggest that the implants give rise to clustering Cu nanoparticles in the host matrix but that the annealing process dissociates these. Numerical modelling of the Cu nanoparticles was employed to simulate their optical properties including the extinction cross section, electron energy loss spectroscopy and cathodoluminescence. We demonstrate that the clustering of nanoparticles generates Fano resonances corresponding to the generation of multiple resonances, while the isolation of nanoparticles results in intensity amplification. - Highlights: • We present the fabrication of metal nanoparticle crystals by implanting Cu into ZnO. • The luminescence properties were studied at different annealing temperature. • Numerical modelling of the Cu nanoparticles was employed. • We demonstrate that the clustering of nanoparticles generates Fano resonances.

  2. A highly selective and sensitive fluorescence assay for determination of copper(II) and cobalt(II) ions in environmental water and toner samples.

    Science.gov (United States)

    Tsai, Chia-Yi; Lin, Yang-Wei

    2013-02-21

    In this study, a highly selective and sensitive fluorescence assay has been proposed for the determination of copper(II) and cobalt(II) ions in environmental water and toner samples. In the presence of hydrogen peroxide, copper(II) reacted with a new fluorescence reagent Amplex® UltraRed (AUR), forming a fluorescence product only at pH 7.0, while the fluorescence product of cobalt(II) with AUR formed only at pH 9.0. The fluorescence signal obtained was linear with respect to the copper(II) concentration over the range of 1.6-12.0 μM (R(2) = 0.988) and was linear with respect to the cobalt(II) concentration over the range of 45.0 nM to 1.0 μM (R(2) = 0.992). The limits of detection (at a signal-to-noise ratio of 3) for copper(II) and cobalt(II) were 0.17 μM and 14.0 nM, respectively. Our present approach is simpler, faster, and more cost-effective than other techniques for the detection of copper(II) and cobalt(II) ions in environmental water samples and that of copper(II) ions in toner samples.

  3. Biosorption of copper(II) ions onto powdered waste sludge in a completely mixed fed-batch reactor: estimation of design parameters.

    Science.gov (United States)

    Pamukoglu, Yunus; Kargi, Fikret

    2007-04-01

    Biosorption of Cu(II) ions onto pre-treated powdered waste sludge (PWS) was investigated using a fed-batch operated completely mixed reactor. Fed-batch adsorption experiments were performed by varying the feed flow rate ( 0.075-0.325 l h(-1)), feed copper (II) ion concentrations (50-300 mg l(-1)) and the amount of adsorbent (1-6 g PWS) using fed-batch operation. Breakthrough curves describing the variations of effluent copper ion concentrations with time were determined for different operating conditions. Percent copper ion removals from the aqueous phase decreased, but the biosorbed (solid phase) copper ion concentrations increased with increasing the feed flow rate and Cu(II) concentration. A modified Bohart-Adams equation was used to determine the biosorption capacity of PWS and the rate constant for Cu(II) ion biosorption. Adsorption rate constant in fed-batch operation was an order of magnitude larger than those obtained in adsorption columns because of elimination of mass transfer limitations encountered in the column operations while the biosorption capacity of PWS was comparable with powdered activated (PAC) in column operations. Therefore, a completely mixed reactor operated in fed-batch mode was proven to be more advantageous as compared to adsorption columns due to better contact between the phases yielding faster adsorption rates.

  4. Microanalysis of oligodeoxynucleotides by cathodic stripping voltammetry at amalgam-alloy surfaces in the presence of copper ions.

    Science.gov (United States)

    Hason, Stanislav; Vetterl, Vladimír

    2006-05-15

    The application of gold amalgam-alloy electrode (AuAE) for a sensitive voltammetric detection of different oligodeoxynucleotides (ODNs) containing the purine units within the ODN-chains in the presence of copper is described. The detection of ODNs is based on the following procedure: (i) the first step includes an acidic hydrolysis of the ODN (ahODN) samples performing the release of the purine bases from ODN-chain; (ii) the second step includes an electrochemical accumulation of the complex of the purine base residues released from ODN-chain with copper ions Cu(I) (ahODN-Cu(I) complex) at the potential of reduction of copper ions Cu(II) on the amalgam-alloy electrode surfaces; (iii) finally followed the cathodic stripping of the electrochemically accumulated ahODN-Cu(I) complex from the electrode surface. The proposed electrochemical method was used for: (a) detection of different ODN lengths containing only adenine units (the number of adenine units within the ODN-chains was changed from 10 to 80), and (b) determination of the number of purine units within the 30-mer ODNs containing a random sequence segments involving both the purine and pyrimidine units. The intensity of the cathodic stripping current density peak (j(CSP)) of the electrochemically accumulated ahODN-Cu(I) complex increased linearly with the increasing number of purine units within the ODN-chains. We observed a good correlation between the percentage content of purine units to the whole length of different 30-mer ODNs and the percentage content of the intensity of the j(CSP) of the electrochemically accumulated 30-mer ahODN-Cu(I) complexes. The detection of acid hydrolysed 80-mer (A(80)) in the bulk solution and in a 20-mul volume is possible down to 200pM and 2nM at the AuAE, respectively. For the shortest 10-mer (A(10)) a detectable value of 5nM in the bulk solution on the AuAE was observed. The sensitive detection of different ODNs containing the purine units in their chains in the presence of

  5. The Formation of Polycomplexes of Poly(Methyl Vinyl Ether-Co-Maleic Anhydride and Bovine Serum Albumin in the Presence of Copper Ions

    Directory of Open Access Journals (Sweden)

    Karahan Mesut

    2014-09-01

    Full Text Available The binary and ternary complex formations of poly(methyl vinyl ether-co-maleic anhydride (PMVEMA with copper ions and with bovine serum albumin (BSA in the presence of copper ions in phosphate buffer solution at pH = 7 were examined by the techniques of UV-visible, fluorescence, dynamic light scattering, atomic force microscopy measurements. In the formation of binary complexes of PMVEMA-Cu(II, the addition of copper ions to the solution of PMVEMA in phosphate buffer solution at pH = 7 forms homogeneous solutions when the molar ratio of Cu(II/MVEMA is 0.5. Then the formations of ternary complexes of PMVEMA-Cu(II-BSA were examined. Study analysis revealed that the toxicities of polymer-metal and polymer-metal-protein mixture solutions depend on the nature and ratio of components in mixtures.

  6. Use of copper slag in glass-epoxy composites for improved wear resistance.

    Science.gov (United States)

    Biswas, Sandhyarani; Satapathy, Alok

    2010-07-01

    Copper slag is a by-product obtained during matte smelting and refining of copper. The common management options for copper slag are recycling, recovery of metal and production of value-added products. In the present study using copper slag as a filler in glass-epoxy composites, the tensile modulus increased from 8.77 GPa to 9.64 GPa when using up to 10 wt% of copper slag but on further addition of copper slag (up to 20 wt%), the tensile modulus started to decrease down to 7.11 GPa. Similar trends were observed in the case of flexural strength and interlaminar shear strength. With the incorporation of copper slag particles, the impact strength increased about 10-15%. This work includes the processing, characterization and study of the erosion behaviour of a class of such copper slag filled glass-epoxy composites based on Taguchi's experimental approach to characterise erosion behaviour. The results show that peak erosion takes place at an impingement angle of 60 degrees for the unfilled composites whereas for the copper slag filled glass-epoxy composites it occurs at a 45 degrees impingement angle. This paper considers the possible utilisation of copper slag as filler material for the preparation of composite materials and preparation of added-value products such as abrasive tools, cutting tools and railroad ballast.

  7. Effect of sorption conditions on the state of copper(II) ions in the phase of AN-31 ion exchange resin, according to data from ESR and UV-vis diffuse reflectance spectroscopy

    Science.gov (United States)

    Stroganova, E. A.; Anufrienko, V. F.; Larina, T. V.; Vasenin, N. T.; Lebedev, Yu. A.; Parmon, V. N.

    2017-08-01

    It is found that the sorption recovery of copper ions from water solutions in the phase of AN-31 low basicity anion exchanger has a mixed character. It is established via diffuse reflectance spectroscopy that ions are stabilized through complexation with the participation of the functional groups of the sorbent with the formation of structures [Cu(NR3)2(OH)2(H2O)2], [Cu(NR3)3(OH)(H2O)2], and as a result of the physical adsorption of oxide dimers and planar-squared copper clusters. It is shown that increasing the ionic strength of a solution by introducing sodium chloride into the system greatly improves the capacity of the sorbent and leads to the uniform distribution of copper ions in the resin matrix. The similarity between the ESR spectrum parameters of copper-containing samples of the ion exchanger, obtained in a wider range of pH, is determined via ESR and testifies to the homogeneity of the stabilization positions of Cu2+ ions. The crystalline field of tetragonal-elongated octahedron is typical of all Cu2+ ions. All of the complexes have Cu(NO3)2 coordination nodes with the covalent bonding of Cu2+ ions and the amine groups of the sorbent.

  8. Bactericidal activity and mechanism of action of copper-sputtered flexible surfaces against multidrug-resistant pathogens.

    Science.gov (United States)

    Ballo, Myriam K S; Rtimi, Sami; Mancini, Stefano; Kiwi, John; Pulgarin, César; Entenza, José M; Bizzini, Alain

    2016-07-01

    Using direct current magnetron sputtering (DCMS), we generated flexible copper polyester surfaces (Cu-PES) and investigated their antimicrobial activity against a range of multidrug-resistant (MDR) pathogens including eight Gram-positive isolates (three methicillin-resistant Staphylococcus aureus [MRSA], four vancomycin-resistant enterococci, one methicillin-resistant Staphylococcus epidermidis) and four Gram-negative strains (one extended-spectrum β-lactamase-producing [ESBL] Escherichia coli, one ESBL Klebsiella pneumoniae, one imipenem-resistant Pseudomonas aeruginosa, and one ciprofloxacin-resistant Acinetobacter baumannii). Bactericidal activity (≥3 log10 CFU reduction of the starting inoculum) was reached within 15-30 min exposure to Cu-PES. Antimicrobial activity of Cu-PES persisted in the absence of oxygen and against both Gram-positive and Gram-negative bacteria containing elevated levels of catalases, indicating that reactive oxygen species (ROS) do not play a primary role in the killing process. The decrease in cell viability of MRSA ATCC 43300 and Enterococcus faecalis V583 correlated with the progressive loss of cytoplasmic membrane integrity both under aerobic and anaerobic conditions, suggesting that Cu-PES mediated killing is primarily induced by disruption of the cytoplasmic membrane function. Overall, we here present novel antimicrobial copper surfaces with improved stability and sustainability and provide further insights into their mechanism of killing.

  9. Carboxymethyl-{beta}-cyclodextrin conjugated magnetic nanoparticles as nano-adsorbents for removal of copper ions: Synthesis and adsorption studies

    Energy Technology Data Exchange (ETDEWEB)

    Badruddoza, A.Z.M.; Tay, A.S.H.; Tan, P.Y.; Hidajat, K. [Department of Chemical and Biomolecular Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260 (Singapore); Uddin, M.S., E-mail: cheshahb@nus.edu.sg [Department of Chemical and Biomolecular Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260 (Singapore)

    2011-01-30

    A novel nano-adsorbent, carboxymethyl-{beta}-cyclodextrin modified Fe{sub 3}O{sub 4} nanoparticles (CMCD-MNPs) is fabricated for removal of copper ions from aqueous solution by grafting CM-{beta}-CD onto the magnetite surface via carbodiimide method. The characteristics results of FTIR, TEM, TGA and XPS show that CM-{beta}-CD is grafted onto Fe{sub 3}O{sub 4} nanoparticles. The grafted CM-{beta}-CD on the Fe{sub 3}O{sub 4} nanoparticles contributes to an enhancement of the adsorption capacity because of the strong abilities of the multiple hydroxyl and carboxyl groups in CM-{beta}-CD to adsorb metal ions. The adsorption of Cu{sup 2+} onto CMCD-MNPs is found to be dependent on pH and temperature. Adsorption equilibrium is achieved in 30 min and the adsorption kinetics of Cu{sup 2+} is found to follow a pseudo-second-order kinetic model. Equilibrium data for Cu{sup 2+} adsorption are fitted well by Langmuir isotherm model. The maximum adsorption capacity for Cu{sup 2+} ions is estimated to be 47.2 mg/g at 25 {sup o}C. Furthermore, thermodynamic parameters reveal the feasibility, spontaneity and exothermic nature of the adsorption process. FTIR and XPS reveal that Cu{sup 2+} adsorption onto CMCD-MNPs mainly involves the oxygen atoms in CM-{beta}-CD to form surface-complexes. In addition, the copper ions can be desorbed from CMCD-MNPs by citric acid solution with 96.2% desorption efficiency and the CMCD-MNPs exhibit good recyclability.

  10. Carboxymethyl-β-cyclodextrin conjugated magnetic nanoparticles as nano-adsorbents for removal of copper ions: synthesis and adsorption studies.

    Science.gov (United States)

    Badruddoza, A Z M; Tay, A S H; Tan, P Y; Hidajat, K; Uddin, M S

    2011-01-30

    A novel nano-adsorbent, carboxymethyl-β-cyclodextrin modified Fe(3)O(4) nanoparticles (CMCD-MNPs) is fabricated for removal of copper ions from aqueous solution by grafting CM-β-CD onto the magnetite surface via carbodiimide method. The characteristics results of FTIR, TEM, TGA and XPS show that CM-β-CD is grafted onto Fe(3)O(4) nanoparticles. The grafted CM-β-CD on the Fe(3)O(4) nanoparticles contributes to an enhancement of the adsorption capacity because of the strong abilities of the multiple hydroxyl and carboxyl groups in CM-β-CD to adsorb metal ions. The adsorption of Cu(2+) onto CMCD-MNPs is found to be dependent on pH and temperature. Adsorption equilibrium is achieved in 30 min and the adsorption kinetics of Cu(2+) is found to follow a pseudo-second-order kinetic model. Equilibrium data for Cu(2+) adsorption are fitted well by Langmuir isotherm model. The maximum adsorption capacity for Cu(2+) ions is estimated to be 47.2mg/g at 25 °C. Furthermore, thermodynamic parameters reveal the feasibility, spontaneity and exothermic nature of the adsorption process. FTIR and XPS reveal that Cu(2+) adsorption onto CMCD-MNPs mainly involves the oxygen atoms in CM-β-CD to form surface-complexes. In addition, the copper ions can be desorbed from CMCD-MNPs by citric acid solution with 96.2% desorption efficiency and the CMCD-MNPs exhibit good recyclability. Copyright © 2010 Elsevier B.V. All rights reserved.

  11. Synergistic inhibition effect of L-phenylalanine and rare earth Ce(IV) ion on the corrosion of copper in hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Daquan, E-mail: zhangdaquan@shiep.edu.cn [Department of Environmental Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Wu Huan; Gao Lixin [Department of Environmental Engineering, Shanghai University of Electric Power, Shanghai 200090 (China)

    2012-04-16

    Highlights: Black-Right-Pointing-Pointer Synergistic effect of L-phenylalanine (L-Phe) and Ce(SO{sub 4}){sub 2} on the corrosion of copper on the corrosion inhibition of copper in 0.5 M HCl solution. Black-Right-Pointing-Pointer Structure of the complex film formed by the interaction of L-phenylalanine (L-Phe) and Ce(SO{sub 4}){sub 2} on the copper surface. Black-Right-Pointing-Pointer Mechanism of the improvement of the inhibition property of amino acids by the addition of rare earth compound. - Abstract: The synergistic inhibition effect of L-phenylalanine (L-Phe) and Ce(SO{sub 4}){sub 2} on the corrosion of copper in 0.5 M HCl solution was investigated by weight-loss, electrochemical methods and surface analysis. The electrochemical results showed that L-Phe has definite inhibition effects for copper, while Ce(IV) promoted the anodic process of copper corrosion. The combination L-Phe with Ce(IV) ion produced strong synergistic effect on corrosion inhibition for copper. The maximum inhibition efficiency was 82.7% for 5 mM L-Phe + 2 mM Ce(IV). The results of EIS and potentiodynamic polarization are in good agreement. SEM showed that L-Phe and Ce(IV) can form a dense protective film on the copper surface.

  12. Ligandless-dispersive liquid-liquid microextraction of trace amount of copper ions

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadi, Sayed Zia, E-mail: szmohammadi@yahoo.com [Department of Chemistry, Payame Noor University (PNU), Kerman (Iran, Islamic Republic of); Afzali, Daryoush [Environment Department, Institute Research of Environmental Sciences, International Center for Science, High Technology and Environmental Sciences, Kerman (Iran, Islamic Republic of); Baghelani, Yar Mohammad [Department of Chemistry, Payame Noor University (PNU), Kerman (Iran, Islamic Republic of)

    2009-10-27

    In the present work, a new ligandless-dispersive liquid-liquid microextraction (LL-DLLME) method has been developed for preconcentration trace amounts of copper as a prior step to its determination by flame atomic absorption spectrometry. In the proposed approach 1,2-dicholorobenzene and ethanol were used as extraction and dispersive solvents, respectively. Some factors influencing on the extraction efficiency of copper and its subsequent determination were studied and optimized, such as the extraction and dispersive solvent type and volume, pH of sample solution, extraction time and salting out effect. Under the optimal conditions, the calibration curve was linear in the range of 1.0 ng mL{sup -1}-0.6 {mu}g mL{sup -1} of copper with R{sup 2} = 0.9985. Detection limit was 0.5 ng mL{sup -1} in original solution (3S{sub b}/m) and the relative standard deviation for seven replicate determination of 0.2 {mu}g mL{sup -1} copper was {+-}1.4%. The proposed method has been applied for determination of copper in standard and water samples with satisfactory results.

  13. Increasing wear resistance of copper friction pair with electrically-conductive tribological Cu-Mo-S coatings

    Science.gov (United States)

    Zharkov, S. Yu.; Sergeev, V. P.; Fedorischeva, M. V.; Sergeev, O. V.; Kalashnikov, M. P.

    2016-11-01

    The composite solid lubricant Cu-Mo-S coating was produced by pulse magnetron sputtering system. The electrical resistivity of deposited Cu-Mo-S coatings was (22.8±3) × 10-8 Ohm×m. Cu-Mo-S coatings decrease the wear rate of the copper friction pair by 38 times. The decrease in the wear rate occurs owing to the formation of a transferred film on the counterface.

  14. Resistance to peroxide degradation of Hyflon ® Ion membranes

    Science.gov (United States)

    Merlo, L.; Ghielmi, A.; Cirillo, L.; Gebert, M.; Arcella, V.

    Perfluorosulfonic acid (PFSA) membranes have been used for 40 years as solid electrolytes in low temperature fuel cells and are considered from the scientific community superior to other polymeric products due to their good combination between chemical resistance and proton conductivity. In recent years, development of the class of PFSA membranes known as 'short side chain' membranes has been restarted from Solvay Solexis (Hyflon ® Ion). Although PFSA are highly stable, still, decay in fuel cell performance might be detected over time due to membrane degradation, especially under certain working conditions. Different degradation mechanisms, mainly based on Nafion ® structure, have been proposed by several Authors and both ex situ and in situ test protocols have been developed to perform accelerated testing. The generally accepted opinion is that the degradation problem is mostly related to peroxide radical attack. A short review of the degradation mechanisms is first presented in this work. For the first time a campaign of chemical degradation tests (open circuit voltage fuel cell operation and ex situ Fenton tests) on the short-side-chain PFSA is presented and discussed, both for standard extruded and chemical stabilized membranes.

  15. A Copper Coordination Compound Produced by a Marine Fungus Fusarium sp. ZZF51 with Biosorption of Cu(Ⅱ) Ions

    Institute of Scientific and Technical Information of China (English)

    TAN Ni; PAN Jia-Hui; PENG Guang-Tian; MOU Cheng-Bo; TAO Yi-Wen; SHE Zhi-Gang; YANG Ze-Liang; ZHOU Shi-Ning; LIN Yong-Cheng

    2008-01-01

    A copper coordination compound ZZF51 (A) named bis(5-butyl-2-pyridinecarboxylato-N1,O2)-copper, the first time found in the nature, was isolated from a marine endophytic fungus Fusarium sp. ZZF51 from the South China Sea coast. Its structure was elucidated using spectroscopic methods and single crystal X-ray diffraction analysis.The antimicrobial cytotoxicity experiments exhibited that ZZF51(A) had mutagenicity activities against four aerobic reference strains Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Salmonella enteritidis with respective MIC values of 12.5, 25, 12.5, and 50 μg/mL. The anti-cancer tests showed that the compound had strong inhibitory activities against three human cancer lines KB, KBv200, and HepG2 with IC50 values of 3.54, 3.68 and 25.12 μg/mL respectively. In the course of investigating the source of ZZF51(A) in biomass, it was found that the output of ZZF51(A) was largely influenced by the amount of CuCl2 in the liquid medium, and the fungus (No.ZZF51) had two notable characteristics: endurance of high concentration Cu(Ⅱ) ions and biosorption of Cu(Ⅱ) ions.

  16. Formation of TiO2 photoanodes by simultaneous electrophoretic deposition of anatase and rutile particles for photoassisted electrolytic copper ions removal

    Directory of Open Access Journals (Sweden)

    Yeimmy Y. Peralta-Ruiz

    2012-01-01

    Full Text Available The influence of Anatasa/Rutile ratio on TiO2 films, grown by electrophoretic deposition was studied in the photoassisted electrolytic copper ions removal from cyanide solutions. The proper dispersant dosage allowing the simultaneous electrophoretic deposition of Anatase and Rutile was chosen based on electrokinetic measurements; evidenced by the XRD spectra of the formed films. The evaluation of films photoassisted electrolytic copper ion removal showeds that it is possible to enhance the activity of Anatase films by adding some Rutile exploiting the synergetic interaction between these two materials, achieve by its proper deposition.

  17. Isolation and Characterization of Bacteria Resistant to Metallic Copper Surfaces▿ †

    OpenAIRE

    Espírito Santo, Christophe; Morais, Paula Vasconcelos; Grass, Gregor

    2010-01-01

    Metallic copper alloys have recently attracted attention as a new antimicrobial weapon for areas where surface hygiene is paramount. Currently it is not understood on a molecular level how metallic copper kills microbes, but previous studies have demonstrated that a wide variety of bacteria, including Escherichia coli, Staphylococcus aureus, and Clostridium difficile, are inactivated within minutes or a few hours of exposure. In this study, we show that bacteria isolated from copper alloy coi...

  18. Molecular basis of active copper resistance mechanisms in Gram-negative bacteria

    OpenAIRE

    Bondarczuk, Kinga; Piotrowska-Seget, Zofia

    2013-01-01

    Copper is a metallic element that is crucial for cell metabolism; however, in extended concentrations, it is toxic for all living organisms. The dual nature of copper has forced organisms, including bacteria, to keep a tight hold on cellular copper content. This challenge has led to the evolution of complex mechanisms that on one hand enable them to deliver the essential element and on the other to protect cells against its toxicity. Such mechanisms have been found in both eukaryotic and prok...

  19. Copper resistance of the evergreen dwarf shrub Arctostaphylos uva-ursi: an experimental exposure

    Energy Technology Data Exchange (ETDEWEB)

    Salemaa, Maija; Monni, Satu

    2003-12-01

    The copper (Cu) resistance of Arctostaphylos uva-ursi was tested in a pot experiment (lasting 8 weeks) using rooted cuttings originating from an area near the Harjavalta Cu-Ni smelter, SW Finland. The fine roots were moderately infected by arbutoid mycorrhizae. The plants were exposed to five Cu levels (1, 10, 22, 46 and 100 mg l{sup -1}) given repeatedly together with a nutrient solution. The critical Cu concentration in the nutrient solution inhibiting the growth of A. uva-ursi was below 10 mg l{sup -1} Cu (EC{sub 50} value for biomass production 3.3 mg l{sup -1} Cu). This concentration was clearly lower than the value we have found earlier for other dwarf shrubs under similar experimental conditions. Most of the Cu given accumulated in the roots and old stems. The results suggest that A. uva-ursi cuttings were relatively sensitive to Cu despite the ability of the adult clones to grow in Cu-contaminated soil. The adult clones extend their roots into the less toxic deeper soil layers, which may facilitate the avoidance of heavy metals. - Root extension into deeper layers of soil may aid in avoidance of heavy metals.

  20. Synthesis and characterization of novel ion-imprinted polymeric nanoparticles for very fast and highly selective recognition of copper(II) ions.

    Science.gov (United States)

    Shamsipur, Mojtaba; Besharati-Seidani, Abbas; Fasihi, Javad; Sharghi, Hashem

    2010-12-15

    This work reports the preparation of new Cu(2+) ion-imprinted polymeric nanoparticles using 1-hydroxy-4-(prop-2'-enyloxy)-9,10-anthraquinone (AQ) as a vinylated chelating agent. The Cu(2+) ion found to form a stable 1:1 complex with AQ in methanol solution. The resulting Cu(2+)-AQ complex was copolymerized with ethyleneglycol dimethacrylate, as a cross-linking monomer, via precipitation polymerization method. The imprint copper ion was removed from the polymeric matrix using a 0.1 mol L(-1) HNO(3) solution. The Cu(2+)-imprinted polymeric nanoparticles were characterized by IR spectroscopy, scanning electron microscopy (SEM) and N(2) adsorption-desorption isotherms. The SEM micrographs showed colloidal nanoparticles of 60-100 nm in diameter and slightly irregular in shape. Optimum pH for maximum sorption was 7.0. Sorption and desorption of Cu(2+) ion on the IIP nanoparticles were quite fast and achieved completely over entire investigated time periods of 2-30 min. Maximum sorbent capacity and enrichment factor of the prepared IIP for Cu(2+) were 73.8 μmol g(-1) and 56.5, respectively. The relative standard deviation and limit of detection (C(LOD)=3S(b)/m) of the method were evaluated as 2.6% and 0.1 ng mL(-1), using inductively coupled plasma-atomic emission spectrometry, respectively. It was found that the imprinting technology results in increased affinity of the prepared material toward Cu(2+) ion over other metal ions with the same charge and close ionic radius. The relative standard deviations for six and twenty replicates with the same nanoparticles were found to be 1.7% and 2.1%, respectively. Copyright © 2010 Elsevier B.V. All rights reserved.

  1. Interaction between Langmuir and Langmuir-Blodgett films of two calix[4]arenes with aqueous copper and lithium ions.

    Science.gov (United States)

    Supian, Faridah L; Richardson, Tim H; Deasy, Mary; Kelleher, Fintan; Ward, James P; McKee, Vickie

    2010-07-06

    The binding interactions between aqueous copper (Cu(2+)) and lithium (Li(+)) ions and Langmuir monolayers and Langmuir-Blodgett (LB) multilayers have been investigated by studying surface pressure-area (Pi-A) isotherms and surface potential-area (DeltaV-A) behavior in order to find the effective dipole moment, mu(perpendicular), of the calixarene molecules in the uncomplexed and complexed states. The orientation of both calix[4]arenes, namely, 5,11,17,23-tetra-tert-butyl-25,27-diethoxycarbonyl methyleneoxy-26,28-dihydroxycalix[4]arene and 5,17-(9H-fluoren-2-yl)methyleneamino)-11,23-di-tert-butyl-25,27-diethoxycarbonyl methyleneoxy-26,28-dihydroxycalix[4]arene, is such that the plane of the calix ring is parallel with the plane of the water surface regardless of the ion content of the subphase. The Gibbs equation was used to interpret the adsorption of ions with both calix[4]arenes as a function of the concentration. Effective dipole moments have been calculated from surface potential values using the Helmholtz equation. In this work, new LB films have been prepared employing two novel amphiphilic calix[4]arene derivatives bearing different upper rim substituents. Thus, the effect of modifiying the upper rim has been observed. The results have shown that these calixarenes may be useful components of ion sensors.

  2. Impact of manganese, copper and zinc ions on the transcriptome of the nosocomial pathogen Enterococcus faecalis V583.

    Directory of Open Access Journals (Sweden)

    Marta Coelho Abrantes

    Full Text Available Mechanisms that enable Enterococcus to cope with different environmental stresses and their contribution to the switch from commensalism to pathogenicity of this organism are still poorly understood. Maintenance of intracellular homeostasis of metal ions is crucial for survival of these bacteria. In particular Zn(2+, Mn(2+ and Cu(2+ are very important metal ions as they are co-factors of many enzymes, are involved in oxidative stress defense and have a role in the immune system of the host. Their concentrations inside the human body vary hugely, which makes it imperative for Enterococcus to fine-tune metal ion homeostasis in order to survive inside the host and colonize it. Little is known about metal regulation in Enterococcus faecalis. Here we present the first genome-wide description of gene expression of E. faecalis V583 growing in the presence of high concentrations of zinc, manganese or copper ions. The DNA microarray experiments revealed that mostly transporters are involved in the responses of E. faecalis to prolonged exposure to high metal concentrations although genes involved in cellular processes, in energy and amino acid metabolisms and genes related to the cell envelope also seem to play important roles.

  3. Handling of Copper and Copper Oxide Nanoparticles by Astrocytes.

    Science.gov (United States)

    Bulcke, Felix; Dringen, Ralf

    2016-02-01

    Copper is an essential trace element for many important cellular functions. However, excess of copper can impair cellular functions by copper-induced oxidative stress. In brain, astrocytes are considered to play a prominent role in the copper homeostasis. In this short review we summarise the current knowledge on the molecular mechanisms which are involved in the handling of copper by astrocytes. Cultured astrocytes efficiently take up copper ions predominantly by the copper transporter Ctr1 and the divalent metal transporter DMT1. In addition, copper oxide nanoparticles are rapidly accumulated by astrocytes via endocytosis. Cultured astrocytes tolerate moderate increases in intracellular copper contents very well. However, if a given threshold of cellular copper content is exceeded after exposure to copper, accelerated production of reactive oxygen species and compromised cell viability are observed. Upon exposure to sub-toxic concentrations of copper ions or copper oxide nanoparticles, astrocytes increase their copper storage capacity by upregulating the cellular contents of glutathione and metallothioneins. In addition, cultured astrocytes have the capacity to export copper ions which is likely to involve the copper ATPase 7A. The ability of astrocytes to efficiently accumulate, store and export copper ions suggests that astrocytes have a key role in the distribution of copper in brain. Impairment of this astrocytic function may be involved in diseases which are connected with disturbances in brain copper metabolism.

  4. Removal of copper ions from aqueous solution by adsorption onto novel polyelectrolyte film-coated nanofibrous silk fibroin non-wovens

    Science.gov (United States)

    Zhou, Weitao; Huang, Haitao; Du, Shan; Huo, Yingdong; He, Jianxin; Cui, Shizhong

    2015-08-01

    In this approach, polyelectrolyte film-coated nanofibrous silk fibroin (SF) nonwovens were prepared from the alternate deposition of positively charged polyethylenimine (PEI) and negatively charged SF using electrostatic layer-by-layer (LBL) self-assembled technology. The composite membranes were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectrometer. The SF-PEI multilayer-assembled nanofibers (less than five layers) were fine and uniform with the fiber diameter from 400 nm to 600 nm, and had very large surface area and high porosity (more than 70%). The amino groups of PEI were proved to be deposited onto SF nonwovens, which granted the coated nonwovens with potential applicability for copper ions adsorption. The PEI films coated SF substrate showed much higher copper ions adsorption capacity than that of ethanol treated SF nanofibers. Adding the number of PEI coated could enhance the Cu2+ adsorption capacity significantly. The maximum milligrams per gram of copper ions adsorbed reached 59.7 mg/g when the SF substrate was coated with 5 bilayers of SF-PEI. However, the copper ions adsorption capacity had no obvious change as the number of PEI continued to increase. These results suggest potential for PEL film-coated nanofibrous nonwovens as a new adsorbent for metal ions.

  5. The effect of copper ions, aluminium ions and their mixtures on separation of pectin from the sugar beet juice

    Directory of Open Access Journals (Sweden)

    Kuljanin Tatjana A.

    2013-01-01

    Full Text Available In sugar industry there is a problem of the presence of undesirable macromolecules compounds such as pectin in sugar beet juice. The affinity of calcium ions commonly used in the sugar industry for the removal of pectin from the sugar beet juice is relatively small. Coagulation and precipitation of pectin can be performed by process of discharging that is chemically induced. Compounds with di- and trivalent cations such as pure CuSO4, Al2(SO43 or their mixtures can be applied for clarification of pectin colloidal systems. According to data from the order of pectin selectivity to divalent metal ions, Cu2+ ions are the first order of ion binding. Also, aluminum sulfate is commonly used in the waste water treatment. Two model solutions of pectin whose concentration corresponds to the concentration of these macromolecules in sugar beet juice (0.1% w/w are investigated. Using a method of measuring zeta potential, it was proven for both investigated pectin that fewer quantities of Cu2+ ions compared to the values of Al3+ ions are needed to reach zero zeta potential. In all the investigated coagulants and their mixtures, zeta potential has changed the sign. In experiments with mixtures has been shown that pure salts showed better coagulation properties. The reduced strength of binding of cations in the case of most of the applied mixture of Cu2+ and Al3+ ions, can be explained by the mutual competition of these ions for the adsorption site (COO- groups on the surface of macromolecules. Mixture with approximately equal shares of ions Cu2+ and Al3+ had the most unfavorable coagulation ability (ion antagonism. Mechanism of discharge as well as the model of double electric layer surrounding pectin macromolecules in the presence of mixtures of Cu2+ and Al3+ ions are suggested. However, due to possible undesirable effects of CuSO4 on food processing, Al2(SO43 is proposed instead of traditional coagulant CaO, not only because of lower consumptions of

  6. Copper-transporting P-type ATPases use a unique ion-release pathway

    DEFF Research Database (Denmark)

    Andersson, Magnus; Mattle, Daniel; Sitsel, Oleg

    2014-01-01

    Heavy metals in cells are typically regulated by PIB-type ATPases. The first structure of the class, a Cu(+)-ATPase from Legionella pneumophila (LpCopA), outlined a copper transport pathway across the membrane, which was inferred to be occluded. Here we show by molecular dynamics simulations...

  7. Combined effects of trapped energetic ions and resistive layer damping on the stability of the resistive wall mode

    Energy Technology Data Exchange (ETDEWEB)

    He, Yuling; Liu, Yue, E-mail: Yueqiang.Liu@ccfe.ac.uk, E-mail: liuyue@dlut.edu.cn; Liu, Chao; Xia, Guoliang [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Liu, Yueqiang, E-mail: Yueqiang.Liu@ccfe.ac.uk, E-mail: liuyue@dlut.edu.cn [CCFE, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041 (China); Department of Earth and Space Science, Chalmers University of Technology, SE-412 96 Gothenburg (Sweden); Wang, Aike; Hao, Guangzhou [Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041 (China); Li, Li [College of Science, Donghua University, Shanghai 201620 (China); Cui, Shaoyan [School of Mathematics and Statistics Science, Ludong University, Yantai 264025 (China)

    2016-01-15

    A dispersion relation is derived for the stability of the resistive wall mode (RWM), which includes both the resistive layer damping physics and the toroidal precession drift resonance damping from energetic ions in tokamak plasmas. The dispersion relation is numerically solved for a model plasma, for the purpose of systematic investigation of the RWM stability in multi-dimensional plasma parameter space including the plasma resistivity, the radial location of the resistive wall, as well as the toroidal flow velocity. It is found that the toroidal favorable average curvature in the resistive layer contributes a significant stabilization of the RWM. This stabilization is further enhanced by adding the drift kinetic contribution from energetic ions. Furthermore, two traditionally assumed inner layer models are considered and compared in the dispersion relation, resulting in different predictions for the stability of the RWM.

  8. Adaptation of genetically monomorphic bacteria: evolution of copper resistance through multiple horizontal gene transfers of complex and versatile mobile genetic elements.

    Science.gov (United States)

    Richard, D; Ravigné, V; Rieux, A; Facon, B; Boyer, C; Boyer, K; Grygiel, P; Javegny, S; Terville, M; Canteros, B I; Robène, I; Vernière, C; Chabirand, A; Pruvost, O; Lefeuvre, P

    2017-04-01

    Copper-based antimicrobial compounds are widely used to control plant bacterial pathogens. Pathogens have adapted in response to this selective pressure. Xanthomonas citri pv. citri, a major citrus pathogen causing Asiatic citrus canker, was first reported to carry plasmid-encoded copper resistance in Argentina. This phenotype was conferred by the copLAB gene system. The emergence of resistant strains has since been reported in Réunion and Martinique. Using microsatellite-based genotyping and copLAB PCR, we demonstrated that the genetic structure of the copper-resistant strains from these three regions was made up of two distant clusters and varied for the detection of copLAB amplicons. In order to investigate this pattern more closely, we sequenced six copper-resistant X. citri pv. citri strains from Argentina, Martinique and Réunion, together with reference copper-resistant Xanthomonas and Stenotrophomonas strains using long-read sequencing technology. Genes involved in copper resistance were found to be strain dependent with the novel identification in X. citri pv. citri of copABCD and a cus heavy metal efflux resistance-nodulation-division system. The genes providing the adaptive trait were part of a mobile genetic element similar to Tn3-like transposons and included in a conjugative plasmid. This indicates the system's great versatility. The mining of all available bacterial genomes suggested that, within the bacterial community, the spread of copper resistance associated with mobile elements and their plasmid environments was primarily restricted to the Xanthomonadaceae family. © 2017 John Wiley & Sons Ltd.

  9. Removal of copper ions from aqueous solution by adsorption onto novel polyelectrolyte film-coated nanofibrous silk fibroin non-wovens

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Weitao, E-mail: weitao_zhou@yahoo.com [Key Laboratory of Functional Textiles, The Education Department of Henan Province, Zhongyuan University of Technology, Zhengzhou 450007 (China); Huang, Haitao [School of Textile, Henan Institute of Engineering, Zhengzhou 451191 (China); Du, Shan [Australian Future Fibers Research and Innovation Centre for Frontier Materials, Deakin University, Geelong, VIC 3217 (Australia); Huo, Yingdong; He, Jianxin [Key Laboratory of Functional Textiles, The Education Department of Henan Province, Zhongyuan University of Technology, Zhengzhou 450007 (China); Cui, Shizhong, E-mail: snowballer@163.com [Key Laboratory of Functional Textiles, The Education Department of Henan Province, Zhongyuan University of Technology, Zhengzhou 450007 (China)

    2015-08-01

    Graphical abstract: - Highlights: • Polyethylenimine coated silk fibroin nanofibrous nonwovens were fabricated. • The characteristics such as the fiber shape and porous structure were well maintained. • The structure and adsorption properties were studied. The adsorption property for copper ions is good. - Abstract: In this approach, polyelectrolyte film-coated nanofibrous silk fibroin (SF) nonwovens were prepared from the alternate deposition of positively charged polyethylenimine (PEI) and negatively charged SF using electrostatic layer-by-layer (LBL) self-assembled technology. The composite membranes were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectrometer. The SF-PEI multilayer-assembled nanofibers (less than five layers) were fine and uniform with the fiber diameter from 400 nm to 600 nm, and had very large surface area and high porosity (more than 70%). The amino groups of PEI were proved to be deposited onto SF nonwovens, which granted the coated nonwovens with potential applicability for copper ions adsorption. The PEI films coated SF substrate showed much higher copper ions adsorption capacity than that of ethanol treated SF nanofibers. Adding the number of PEI coated could enhance the Cu{sup 2+} adsorption capacity significantly. The maximum milligrams per gram of copper ions adsorbed reached 59.7 mg/g when the SF substrate was coated with 5 bilayers of SF-PEI. However, the copper ions adsorption capacity had no obvious change as the number of PEI continued to increase. These results suggest potential for PEL film-coated nanofibrous nonwovens as a new adsorbent for metal ions.

  10. Magnetic Graphene Nanosheet-Based Microfluidic Device for Homogeneous Real-Time Electronic Monitoring of Pyrophosphatase Activity Using Enzymatic Hydrolysate-Induced Release of Copper Ion.

    Science.gov (United States)

    Lin, Youxiu; Zhou, Qian; Li, Juan; Shu, Jian; Qiu, Zhenli; Lin, Yuping; Tang, Dianping

    2016-01-01

    A novel flow-through microfluidic device based on a magneto-controlled graphene sensing platform was designed for homogeneous electronic monitoring of pyrophosphatase (PPase) activity; enzymatic hydrolysate-induced release of inorganic copper ion (Cu(2+)) from the Cu(2+)-coordinated pyrophosphate ions (Cu(2+)-PPi) complex was assessed to determine enzyme activity. Magnetic graphene nanosheets (MGNS) functionalized with negatively charged Nafion were synthesized by using the wet-chemistry method. The Cu(2+)-PPi complexes were prepared on the basis of the coordination reaction between copper ion and inorganic pyrophosphate ions. Upon target PPase introduction into the detection system, the analyte initially hydrolyzed pyrophosphate ions into phosphate ions and released the electroactive copper ions from Cu(2+)-PPi complexes. The released copper ions could be readily captured through the negatively charged Nafion on the magnetic graphene nanosheets, which could be quantitatively monitored by using the stripping voltammetry on the flow-through detection cell with an external magnet. Under optimal conditions, the obtained electrochemical signal exhibited a high dependence on PPase activity within a dynamic range from 0.1 to 20 mU mL(-1) and allowed the detection at a concentration as low as 0.05 mU mL(-1). Coefficients of variation for reproducibility of the intra-assay and interassay were below 7.6 and 9.8%, respectively. The inhibition efficiency of sodium fluoride (NaF) also received good results in pyrophosphatase inhibitor screening research. In addition, the methodology afforded good specificity and selectivity, simplification, and low cost without the need of sample separations and multiple washing steps, thus representing a user-friendly protocol for practical utilization in a quantitative PPase activity.

  11. Effect of copper content in the new conductive material Cu-SPB used in low-temperature Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Yaqub, Adnan; Pervez, Syed Atif; Farooq, Umer; Saleem, Mohsin; Doh, Chilhoon [Korea Electro-technology Research Institute, Changwon (Korea, Republic of); University of Science and Technology, Daejeon (Korea, Republic of); Lee, Youjin; Hwang, Minji; Choi, Jeonghee; Kim, Doohun [Korea Electro-technology Research Institute, Changwon (Korea, Republic of)

    2014-08-15

    A new conductive material, copper/Super-P carbon black composite (Cu-SPB), is prepared via an efficient ion reducing method for use in low-temperature lithium-ion batteries (LIBs). The present study investigated the effects of copper content on the low-temperature performance of LIBs. Electrodes prepared with a high-copper-content conductive material (Cu = 18.54%) showed remarkably improved performance in terms of capacity retention (around 40%), cycling stability, and columbic efficiency. The electrochemical impedance spectroscopy (EIS) analysis revealed that the presence of higher Cu contents could reduce the cell's impedance. The results were also confirmed by using a coin-type full cell's improved capacity retention, which indicated the significance of Cu particles in enhancing the low-temperature performance of LIBs.

  12. Coumarin-Based Fluorescent Probes for Dual Recognition of Copper(II and Iron(III Ions and Their Application in Bio-Imaging

    Directory of Open Access Journals (Sweden)

    Olimpo García-Beltrán

    2014-01-01

    Full Text Available Two new coumarin-based “turn-off” fluorescent probes, (E-3-((3,4-dihydroxybenzylideneamino-7-hydroxy-2H-chromen-2-one (BS1 and (E-3-((2,4-dihydroxybenzylideneamino-7-hydroxy-2H-chromen-2-one (BS2, were synthesized and their detection of copper(II and iron(III ions was studied. Results show that both compounds are highly selective for Cu2+ and Fe3+ ions over other metal ions. However, BS2 is detected directly, while detection of BS1 involves a hydrolysis reaction to regenerate 3-amino-7-hydroxycoumarin (3 and 3,4-dihydroxybenzaldehyde, of which 3 is able to react with copper(II or iron(III ions. The interaction between the tested compounds and copper or iron ions is associated with a large fluorescence decrease, showing detection limits of ca. 10−5 M. Preliminary studies employing epifluorescence microscopy demonstrate that Cu2+ and Fe3+ ions can be imaged in human neuroblastoma SH-SY5Y cells treated with the tested probes.

  13. Coumarin-based fluorescent probes for dual recognition of copper(II) and iron(III) ions and their application in bio-imaging.

    Science.gov (United States)

    García-Beltrán, Olimpo; Cassels, Bruce K; Pérez, Claudio; Mena, Natalia; Núñez, Marco T; Martínez, Natalia P; Pavez, Paulina; Aliaga, Margarita E

    2014-01-13

    Two new coumarin-based "turn-off" fluorescent probes, (E)-3-((3,4-dihydroxybenzylidene)amino)-7-hydroxy-2H-chromen-2-one (BS1) and (E)-3-((2,4-dihydroxybenzylidene)amino)-7-hydroxy-2H-chromen-2-one (BS2), were synthesized and their detection of copper(II) and iron(III) ions was studied. Results show that both compounds are highly selective for Cu²⁺ and Fe³⁺ ions over other metal ions. However, BS2 is detected directly, while detection of BS1 involves a hydrolysis reaction to regenerate 3-amino-7-hydroxycoumarin (3) and 3,4-dihydroxybenzaldehyde, of which 3 is able to react with copper(II) or iron(III) ions. The interaction between the tested compounds and copper or iron ions is associated with a large fluorescence decrease, showing detection limits of ca. 10⁻⁵ M. Preliminary studies employing epifluorescence microscopy demonstrate that Cu²⁺ and Fe³⁺ ions can be imaged in human neuroblastoma SH-SY5Y cells treated with the tested probes.

  14. Disposable competitive-type immunoassay for determination of aflatoxin B1 via detection of copper ions released from Cu-apatite.

    Science.gov (United States)

    Wang, Huan; Zhang, Yihe; Chu, Yanguang; Ma, Hongmin; Li, Yan; Wu, Dan; Du, Bin; Wei, Qin

    2016-01-15

    A disposable electrochemical immunosensor was developed for detection of aflatoxin B1 (AFB1) based on stripping voltammetric detection of copper ions released from Cu-apatite. AFB1 antibody (Ab) was firstly fixed on the gold nanoparticle (Au NPs) modified screen-printed carbon electrode (SPCE). AFB1-bovine serum albumin (AFB1-BSA) conjugate was labeled with Cu-apatite, and then competed with AFB1 for binding to the Ab. Copper ions were released from Cu-apatite through acidolysis and stripping voltammetry signal of the copper ions was used for the detection. The Cu-apatite increased the amount of loaded copper ions, and the anodic stripping strategy performed in the micro electrolytic cell of the SPCE simplified the detection procedure and further amplified the electrochemical signal. This immunosensor could detect AFB1 over a wide concentration range from 0.001 to 100ng mL(-1) with a detection limit of 0.2pg mL(-1). The low cost, high sensitive, rapid and accurate method may find widely potential application in the detection of other toxic or harmful substances.

  15. Fluorescent sensor for selective determination of copper ion based on N-acetyl-L-cysteine capped CdHgSe quantum dots.

    Science.gov (United States)

    Wang, Qingqing; Yu, Xiangyang; Zhan, Guoqing; Li, Chunya

    2014-04-15

    Using N-acetyl-L-cysteine as a stabilizer, well water-dispersed, high-quality and stable CdHgSe quantum dots were facilely synthesized via a simple aqueous phase method. The as-prepared N-acetyl-L-cysteine capped CdHgSe quantum dots were thoroughly characterized by transmission electron microscopy, X-ray diffraction spectroscopy and FTIR. A fluorescent sensor for selective determination of copper ions was developed using N-acetyl-L-cysteine capped CdHgSe quantum dots as fluorescent probe. The fluorescence intensity of N-acetyl-L-cysteine capped CdHgSe quantum dots decreased when interacted with copper ions due to the formation of coordination complex and aggregates. The method possesses high selectivity and is not influenced by some potential interferences such as Ag(+), Zn(2+), Co(2+) and Ni(2+). Under the optimal conditions, the change of fluorescence intensity (ΔI) was linearly proportional to the concentration of copper ions in the range of 1.0×10(-9)-4.0×10(-7) mol L(-1), with a detection limit as low as 2.0×10(-10) mol L(-1) (S/N=3). The developed method had been successfully employed to determine Cu(2+) in shrimp and South-lake water samples, and the results were verified by atomic absorption spectroscopy. The fluorescent sensor was demonstrated to be selective, sensitive and simple for copper ion determination, and promise for practical applications.

  16. Simple Colorimetric Detection of Amyloid β-peptide (1-40) based on Aggregation of Gold Nanoparticles in the Presence of Copper Ions.

    Science.gov (United States)

    Zhou, Yanli; Dong, Hui; Liu, Lantao; Xu, Maotian

    2015-05-13

    A simple method for specific colorimetric sensing of Alzheimer's disease related amyloid-β peptide (Aβ) is developed based on the aggregation of gold nanoparticles in the presence of copper ion. The detection of limit for Aβ(1-40) is 0.6 nM and the promising results from practical samples (human serum) indicate the great potential for the routine detection.

  17. Biosorption of copper ions from dilute aqueous solutions on base treated rubber (Hevea brasiliensis) leaves powder: kinetics, isotherm, and biosorption mechanisms

    Institute of Scientific and Technical Information of China (English)

    W. S. Wan Ngah; M. A. K. M. Hanafiah

    2008-01-01

    The efficiency of sodium hydroxide treated rubber (Hevea brasiliensis) leaves powder (NHBL) for removing copper ions fromaqueous solutions has been investigated. The effects of physicochemical parameters on biosorption capacities such as stirring speed,pH, biosorbent dose, initial concentrations of copper, and ionic strength were studied. The biosorption capacities of NHBL increasedwith increase in pH, stirring speed and copper concentration hut decreased with increase in biosorbent dose and ionic strength. Theisotherm study indicated that NHBL fitted well with Langmuir model compared to Freundlich and Dubinin-Radushkevich models. Themaximum biosorption capacity determined from Langmuir isotherm was 14.97 mg/g at 27~C. The kinetic study revealed that pseudo-second order model fitted well the kinetic data, while Boyd kinetic model indicated that film diffusion was the main rate determiningstep in biosorption process. Based on surface area analysis, NHBL has low surface area and categorized as macroporous. Fouriertransform infrared (FT-IR) analyses revealed that hydroxyl, carboxyl, and amino are the main functional groups involved in the bindingof copper ions. Complexation was one of the main mechanisms for the removal of copper ions as indicated by FT-IR spectra. Ionexchange was another possible mechanism since the ratio of adsorbed cations (Cu2+ and H+) to the released cations (Na, Ca, andMg) from NHBL was almost unity. Copper ions bound on NHBL were able to be desorbed at>99% using 0.05 mol/L HCI, 0.01mol/L HNO, and 0.01 mol/L EDTA solutions.

  18. Photophysical studies of the interactions of poly(amidoamine) generation zero (PAMAM G0) with copper and zinc ions

    Energy Technology Data Exchange (ETDEWEB)

    López-Cabaña, Z.E. [Laboratory of Asymmetric Synthesis, Chemistry Institute of Natural Resources, University of Talca (Chile); Valdés, O. [Nanobiotechnology Division at University of Talca, Fraunhofer Chile Research Foundation – Center for Systems Biotechnology, FCR-CSB, P.O. Box 747 Talca (Chile); Vergara, C.E. [Laboratory of Asymmetric Synthesis, Chemistry Institute of Natural Resources, University of Talca (Chile); Camarada, M.B. [Universidad Andrés Bello, Facultad de Biología, Center for Bioinformatics and Integrative Biology (CBIB), República 239, Santiago (Chile); Fundación Fraunhofer Chile Research, M. Sánchez Fontecilla 310 piso 14, Las Condes (Chile); Nachtigall, F.M. [Nanobiotechnology Division at University of Talca, Fraunhofer Chile Research Foundation – Center for Systems Biotechnology, FCR-CSB, P.O. Box 747 Talca (Chile); González-Nilo, F.D. [Universidad Andrés Bello, Facultad de Biología, Center for Bioinformatics and Integrative Biology (CBIB), República 239, Santiago (Chile); Fundación Fraunhofer Chile Research, M. Sánchez Fontecilla 310 piso 14, Las Condes (Chile); Santos, Leonardo S., E-mail: lssantos@utalca.cl [Laboratory of Asymmetric Synthesis, Chemistry Institute of Natural Resources, University of Talca (Chile); Nanobiotechnology Division at University of Talca, Fraunhofer Chile Research Foundation – Center for Systems Biotechnology, FCR-CSB, P.O. Box 747 Talca (Chile)

    2015-08-15

    This study reports the photophysical behavior of poly(amidoamine) generation zero (PAMAM G0) in the presence of Cu(II) and Zn(II) ions in aqueous solutions using absorption and fluorescence spectroscopy. Theoretical and experimental results confirmed the presence of a strong covalent metal–ligand interaction between PAMAM G0 and copper ion that favored the formation of a ligand–metal charge transfer band coordination complex. In the case of Zn(II), no complex formation with PAMAM G0 was registered. Structure analysis identified the presence of aggregate like PAMAM G0–Zn moieties that generated an enhancement in the fluorescence emission of PAMAM G0. - Highlights: • Photophysical behavior of PAMAM G0 dendrimer with Cu and Zn ions was studied. • Strong covalent metal–ligand interaction was confirmed between PAMAM G0–Cu(II). • No complex formation with PAMAM G0 was registered in the case of Zn(II). • Dendrimer aggregate generated an enhancement in fluorescence emission.

  19. Trapping of muscle relaxant methocarbamol degradation product by complexation with copper(II) ion: Spectroscopic and quantum chemical studies

    Science.gov (United States)

    Mansour, Ahmed M.; Shehab, Ola R.

    2014-07-01

    Structural properties of methocarbamol (Mcm) were extensively studied both experimentally and theoretically using FT IR, 1H NMR, UV-Vis., geometry optimization, Mulliken charge, and molecular electrostatic potential. Stability arises from hyper-conjugative interactions, charge delocalization and H-bonding was analyzed using natural bond orbital (NBO) analysis. Mcm was decomposed in ethanol/water mixture at 80 °C to guaifenesin [(RS)-3-(2-methoxyphenoxy)propane-1,2-diol] and carbamate ion [NH2COO-], where the degradation mechanism was explained by trapping the carbamate ion via the complexation with copper(II) ion. The structure of the isolated complex ([Cu(NH2COO)2(H2O)]ṡ4H2O) was elucidated by spectral, thermal, and magnetic tools. Electronic spectra were discussed by TD-DFT and the descriptions of frontier molecular orbitals and the relocations of the electron density were determined. Calculated g-tensor values showed best agreement with experimental values from EPR when carried out using both the B3LYP and B3PW91 functional.

  20. Extended adsorption transport models for permeation of copper ions through nanocomposite chitosan/polyvinyl alcohol thin affinity membranes

    Institute of Scientific and Technical Information of China (English)

    Ehsan Salehi; Leila Bakhtiari; Mahdi Askari

    2016-01-01

    Transport of copper ions through nanocomposite chitosan/polyvinyl alcohol thin adsorptive membranes has been mathematical y investigated in the current study. Unsteady-state diffusive transport model was coupled with the Freundlich isotherm to predict the concentration of the ions in dialysis permeation operation. Pristine model was not successful in predicting the experimental data based upon its low coefficients of determination (0.1﹤R2﹤0.65). Well-behaved polynomial and exponential functions were used to describe time-dependency of the inlet-concentration in the first extension of the model with a little improvement in the model adjustment (0.4﹤R2﹤0.69). Similar time-dependent functions were employed for tracking the ion diffusivity and then applied in combination with the optimized functions of inlet-concentration in the second extension of the model. A sensible enhancement was obtained in the adjustment of the second extended models as a result of this combination (0.73﹤R2﹤0.93). APRE, AAPRE, RSME, RMSE, STD and R-square statistical analyses were per-formed to verify the agreement of the models with the experimental results. Concentration distribution versus time and location (inside the membrane) was obtained as 3D plots with the help of the optimized models. Modeling results emphasized on the transiency of diffusivity and feed-side concentration in dialysis permeation through chitosan membranes.

  1. Cloud point extraction for the determination of copper, nickel and cobalt ions in environmental samples by flame atomic absorption spectrometry.

    Science.gov (United States)

    Ghaedi, M; Shokrollahi, A; Ahmadi, F; Rajabi, H R; Soylak, M

    2008-02-11

    A cloud point extraction procedure was presented for the preconcentration of copper, nickel and cobalt ions in various samples. After complexation with methyl-2-pyridylketone oxime (MPKO) in basic medium, analyte ions are quantitatively extracted to the phase rich in Triton X-114 following centrifugation. 1.0 mol L(-1) HNO(3) nitric acid in methanol was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). The adopted concentrations for MPKO, Triton X-114 and HNO(3), bath temperature, centrifuge rate and time were optimized. Detection limits (3 SDb/m) of 1.6, 2.1 and 1.9 ng mL(-1) for Cu(2+), Co(2+) and Ni(2+) along with preconcentration factors of 30 and for these ions and enrichment factor of 65, 58 and 67 for Cu(2+), Ni(2+) and Co(2+), respectively. The high efficiency of cloud point extraction to carry out the determination of analytes in complex matrices was demonstrated. The proposed procedure was applied to the analysis of biological, natural and wastewater, soil and blood samples.

  2. Cloud point extraction for the determination of copper, nickel and cobalt ions in environmental samples by flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ghaedi, M. [Chemistry Department, University of Yasouj, Yasouj 75914-353 (Iran, Islamic Republic of)], E-mail: m_ghaedi@mail.yu.ac.ir; Shokrollahi, A.; Ahmadi, F.; Rajabi, H.R. [Chemistry Department, University of Yasouj, Yasouj 75914-353 (Iran, Islamic Republic of); Soylak, M. [Chemistry Department, University of Erciyes, 38039 Kayseri (Turkey)

    2008-02-11

    A cloud point extraction procedure was presented for the preconcentration of copper, nickel and cobalt ions in various samples. After complexation with methyl-2-pyridylketone oxime (MPKO) in basic medium, analyte ions are quantitatively extracted to the phase rich in Triton X-114 following centrifugation. 1.0 mol L{sup -1} HNO{sub 3} nitric acid in methanol was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). The adopted concentrations for MPKO, Triton X-114 and HNO{sub 3}, bath temperature, centrifuge rate and time were optimized. Detection limits (3 SDb/m) of 1.6, 2.1 and 1.9 ng mL{sup -1} for Cu{sup 2+}, Co{sup 2+} and Ni{sup 2+} along with preconcentration factors of 30 and for these ions and enrichment factor of 65, 58 and 67 for Cu{sup 2+}, Ni{sup 2+} and Co{sup 2+}, respectively. The high efficiency of cloud point extraction to carry out the determination of analytes in complex matrices was demonstrated. The proposed procedure was applied to the analysis of biological, natural and wastewater, soil and blood samples.

  3. Non-noble metal graphene oxide-copper (II) ions hybrid electrodes for electrocatalytic hydrogen evolution reaction

    KAUST Repository

    Muralikrishna, S.

    2015-08-25

    Non-noble metal and inexpensive graphene oxide-copper (II) ions (GO-Cu2+) hybrid catalysts have been explored for the hydrogen evolution reaction (HER). We were able to tune the binding abilities of GO toward the Cu2+ ions and hence their catalytic properties by altering the pH. We have utilized the oxygen functional moieties such as carboxylate, epoxide, and hydroxyl groups on the edge and basal planes of the GO for binding the Cu2+ ions through dative bonds. The GO-Cu2+ hybrid materials were characterized by cyclic voltammetry in sodium acetate buffer solution. The morphology of the hybrid GO-Cu2+ was characterized by atomic force microscopy. The GO-Cu2+ hybrid electrodes show good electrocatalytic activity for HER with low overpotential in acidic solution. The Tafel slope for the GO-Cu2+ hybrid electrode implies that the primary discharge step is the rate determining step and HER proceed with Volmer step. © 2015 American Institute of Chemical Engineers Environ Prog.

  4. REMOVAL OF COPPER IONS USING ALIQUAT 336/TBP BASED SUPPORTED LIQUID MEMBRANE

    Directory of Open Access Journals (Sweden)

    Baghdad Medjahed

    2014-03-01

    Full Text Available The sorption of copper (II present in an aqueous media using a supported liquid membrane (SLM by chloride tri-N-octylmethylammonium (Aliquat 336 and Tri-n-butylphosphate (TBP from molar ratio 1:1, with polytetrafluoroethylene (PTFE as a membrane support was studied. The effects of various parameters as initial pH, KSCN concentration and ammonium acetate concentration on the extraction yield were carried out. By a calculation program using CHEAQS V. L20.1, the determination of the percentages of the present species before and after extraction were given, in aqueous medium and on the membrane to be able to determine the relation between the nature of the extracted species and the extraction yield. The 23 factorial design achieve the best conditions of recovery procedure. The recovery of copper (II is almost quantitative (94 %, in one step.

  5. The effects of argon ion bombardment on the corrosion resistance of tantalum

    Science.gov (United States)

    Ramezani, A. H.; Sari, A. H.; Shokouhy, A.

    2017-02-01

    Application of ion beam has been widely used as a surface modification method to improve surface properties. This paper investigates the effect of argon ion implantation on surface structure as well as resistance against tantalum corrosion. In this experiment, argon ions with energy of 30 keV and in doses of 1 × 1017-10 × 1017 ions/cm2 were used. The surface bombardment with inert gases mainly produces modified topography and morphology of the surface. Atomic Force Microscopy was also used to patterned the roughness variations prior to and after the implantation phase. Additionally, the corrosion investigation apparatus wear was applied to compare resistance against tantalum corrosion both before and after ion implantation. The results show that argon ion implantation has a substantial impact on increasing resistance against tantalum corrosion. After the corrosion test, scanning electron microscopy (SEM) analyzed the samples' surface morphologies. In addition, the elemental composition is characterized by energy-dispersive X-ray (EDX) analysis. The purpose of this paper was to obtain the perfect condition for the formation of tantalum corrosion resistance. In order to evaluate the effect of the ion implantation on the corrosion behavior, potentiodynamic tests were performed. The results show that the corrosion resistance of the samples strongly depends on the implantation doses.

  6. Copper bis(diphosphine) complexes: radiopharmaceuticals for the detection of multi-drug resistance in tumours by PET

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, J.S.; Dearling, J.L.S.; Blower, P.J. [Research School of Biosciences, University of Kent, Canterbury (United Kingdom); Sosabowski, J.K.; Zweit, J.; Carnochan, P.; Kelland, L.R.; Coley, H.M. [Joint Department of Physics and CRC Centre for Cancer Therapeutics, Institute for Cancer Research, Royal Marsden Hospital, Sutton (United Kingdom)

    2000-06-01

    Experience with imaging of the multi-drug resistance (MDR) phenotype in tumours using technetium-99m sestamibi, a substrate of the P-glycoprotein (Pgp) transporter, suggests that better quantification of images and separation of MDR from other variables affecting tracer uptake in tumours are required. One approach to these problems is the development of short half-life positron-emitting tracers which are substrates of Pgp. Several lipophilic cationic copper(I) bis(diphosphine) complexes labelled with copper-64 have been synthesised and evaluated in vitro as substrates for Pgp. The synthesis is rapid and efficient with no need for purification steps. The chemistry is suitable for use with very short half-life radionuclides such as copper-62 (9.7 min) and copper-60 (23.7 min). Incubation of the complexes with human serum in vitro showed that they are sufficiently stable in serum to support clinical imaging, and the more lipophilic members of the series are taken up rapidly by cells (Chinese hamster ovary and human ovarian carcinoma) in vitro with great avidity. Uptake in human ovarian carcinoma cells is significantly reduced after several months of conditioning in the presence of doxorubicin, which induces increased Pgp expression. Uptake in hooded rat sarcoma (HSN) cells, which express Pgp, is significantly increased in the presence of the MDR modulator cyclosporin A. Biodistribution studies in hooded rats show rapid blood clearance, excretion through both kidneys and liver, and low uptake in other tissues. The one complex investigated in HSN tumour-bearing rats showed uptake in tumour increasing up to 30 min p.i. while it was decreasing in other tissues. We conclude that diphosphine ligands offer a good basis for development of radiopharmaceuticals containing copper radionuclides, and that this series of complexes should undergo further evaluation in vivo as positron emission tomography imaging agents for MDR. (orig.)

  7. Simultaneous spectrophotometric determination of trace copper, nickel, and cobalt ions in water samples using solid phase extraction coupled with partial least squares approaches

    Science.gov (United States)

    Guo, Yugao; Zhao, He; Han, Yelin; Liu, Xia; Guan, Shan; Zhang, Qingyin; Bian, Xihui

    2017-02-01

    A simultaneous spectrophotometric determination method for trace heavy metal ions based on solid-phase extraction coupled with partial least squares approaches was developed. In the proposed method, trace metal ions in aqueous samples were adsorbed by cation exchange fibers and desorbed by acidic solution from the fibers. After the ion preconcentration process, the enriched solution was detected by ultraviolet and visible spectrophotometer (UV-Vis). Then, the concentration of heavy metal ions were quantified by analyzing ultraviolet and visible spectrum with the help of partial least squares (PLS) approaches. Under the optimal conditions of operation time, flow rate and detection parameters, the overlapped absorption peaks of mixed ions were obtained. The experimental data showed that the concentration, which can be calculated through chemometrics method, of each metal ion increased significantly. The heavy metal ions can be enriched more than 80-fold. The limits of detection (LOD) for the target analytes of copper ions (Cu2 +), cobalt ions (Co2 +) and nickel ions (Ni2 +) mixture was 0.10 μg L- 1, 0.15 μg L- 1 and 0.13 μg L- 1, respectively. The relative standard deviations (RSD) were less than 5%. The performance of the solid-phase extraction can enrich the ions efficiently and the combined method of spectrophotometric detection and PLS can evaluate the ions concentration accurately. The work proposed here is an interesting and promising attempt for the trace ions determination in water samples and will have much more applied field.

  8. Microstructural Features and Properties of High-hardness and Heat-resistant Dispersion Strengthened Copper by Reaction Milling

    Institute of Scientific and Technical Information of China (English)

    YAN Peng; LIN Chenguang; CUI Shun; LU Yanjie; ZHOU Zenglin; LI Zengde

    2011-01-01

    The oxide dispersion strengthened copper alloys are attractive due to their excellent combination of thermal and electrical conductivities,high-temperature strength and microstructure stability.To date,the state-of-art to fabrication of them was the intemal oxidation (IO) process.In this paper,alumina dispersion strengthened copper (ADSC) powders of nominal composition of Cu-2.5 vo1%Al2O3 were produced by reaction milling (RM) process which was an in-situ gas-solid reaction process.The bulk ADSC alloys for electrical and mechanical properties investigation were obtained by sintering and thereafter hot extrusion.After the hot consolidation processes,the fully densified powder compacts can be obtained.The single y-Al2O3 phase and profile broaden effects are evident in accordance with the results of X-ray diffraction (XRD); the HRB hardness of the ADSC can be as high as 95; the outcomes should be attributed to the pinning effect ofnano γ-Al2O3 on dislocations and grain boundaries in the copper matrix.The electrical conductivity of the ADSC alloy is 55%IACS (International Annealing Copper Standard).The room temperature hardness of the hot consolidated material was approximately maintained after annealing for l h at 900 ℃ in hydrogen atmosphere.In terms of the above merits,the RM process to fabricating ADSC alloys is a promising method to improve heat resistance,hardness,electrical conductivity and wear resistance properties etc.

  9. Removal of copper (II), iron (III) and lead (II) ions from Mono ...

    African Journals Online (AJOL)

    EJIRO

    The adsorption of Pb (II) was found to be maximum (94%±3.2) at pH 5, temperature of 100°C, metal ion concentration of ... Key words: Metal ions, adsorption, simulated effluent, coconut husk. INTRODUCTION ..... activated carbon and zeolite.

  10. A Room Temperature Nitric Oxide Gas Sensor Based on a Copper-Ion-Doped Polyaniline/Tungsten Oxide Nanocomposite

    Science.gov (United States)

    Wang, Shih-Han; Shen, Chi-Yen; Su, Jian-Ming; Chang, Shiang-Wen

    2015-01-01

    The parts-per-billion-level nitric oxide (NO) gas sensing capability of a copper-ion-doped polyaniline/tungsten oxide nanocomposite (Cu2+/PANI/WO3) film coated on a Rayleigh surface acoustic wave device was investigated. The sensor developed in this study was sensitive to NO gas at room temperature in dry nitrogen. The surface morphology, dopant distribution, and electric properties were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy mapping, and Hall effect measurements, respectively. The Cu2+/PANI/WO3 film exhibited high NO gas sensitivity and selectivity as well as long-term stability. At 1 ppb of NO, a signal with a frequency shift of 4.3 ppm and a signal-to-noise ratio of 17 was observed. The sensor exhibited distinct selectivity toward NO gas with no substantial response to O2, NH3 and CO2 gases. PMID:25811223

  11. Highly sensitive detection of copper ions by densely grafting fluorescein inside polyethyleneimine core-silica shell nanoparticles.

    Science.gov (United States)

    Qiao, Yali; Zheng, Xingwang

    2015-12-21

    In this work, polyethyleneimine (PEI) core-silica shell nanoparticles were synthesized and used for densely grafting fluorescent receptor units inside the core of these particles to result in multi-receptor units collectively sensing a target. Herein, copper ion quenching of the fluorescence intensity of a fluorescein isothiocyanate (FITC) system was selected as a model to confirm our proof-of-concept strategy. Our results showed that, compared to free FITC in solution, a 10-fold enhancement of the Stern-Volmer constant value for Cu(2+) quenching of the fluorescence intensity of the grafted state of FITC in PEI core-silica shell nanoparticles was achieved. Furthermore, compared to a previous collective sensing scheme by densely grafting fluorescent receptor units on a silica nanoparticle surface, the proposed scheme, which grafted fluorescent receptor units inside a polymer nano-core, was simple, highly efficient and presented higher sensitivity.

  12. A Room Temperature Nitric Oxide Gas Sensor Based on a Copper-Ion-Doped Polyaniline/Tungsten Oxide Nanocomposite

    Directory of Open Access Journals (Sweden)

    Shih-Han Wang

    2015-03-01

    Full Text Available The parts-per-billion-level nitric oxide (NO gas sensing capability of a copper-ion-doped polyaniline/tungsten oxide nanocomposite (Cu2+/PANI/WO3 film coated on a Rayleigh surface acoustic wave device was investigated. The sensor developed in this study was sensitive to NO gas at room temperature in dry nitrogen. The surface morphology, dopant distribution, and electric properties were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy mapping, and Hall effect measurements, respectively. The Cu2+/PANI/WO3 film exhibited high NO gas sensitivity and selectivity as well as long-term stability. At 1 ppb of NO, a signal with a frequency shift of 4.3 ppm and a signal-to-noise ratio of 17 was observed. The sensor exhibited distinct selectivity toward NO gas with no substantial response to O2, NH3 and CO2 gases.

  13. A room temperature nitric oxide gas sensor based on a copper-ion-doped polyaniline/tungsten oxide nanocomposite.

    Science.gov (United States)

    Wang, Shih-Han; Shen, Chi-Yen; Su, Jian-Ming; Chang, Shiang-Wen

    2015-03-24

    The parts-per-billion-level nitric oxide (NO) gas sensing capability of a copper-ion-doped polyaniline/tungsten oxide nanocomposite (Cu(2+)/PANI/WO3) film coated on a Rayleigh surface acoustic wave device was investigated. The sensor developed in this study was sensitive to NO gas at room temperature in dry nitrogen. The surface morphology, dopant distribution, and electric properties were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy mapping, and Hall effect measurements, respectively. The Cu(2+)/PANI/WO3 film exhibited high NO gas sensitivity and selectivity as well as long-term stability. At 1 ppb of NO, a signal with a frequency shift of 4.3 ppm and a signal-to-noise ratio of 17 was observed. The sensor exhibited distinct selectivity toward NO gas with no substantial response to O2, NH3 and CO2 gases.

  14. New insights into single-compound and binary adsorption of copper and lead ions on a treated sea mango shell: experimental and theoretical studies.

    Science.gov (United States)

    Sellaoui, Lotfi; Edi Soetaredjo, Felycia; Ismadji, Suryadi; Cláudio Lima, Éder; Dotto, Guilherme L; Ben Lamine, Abdelmottaleb; Erto, Alessandro

    2017-09-21

    Herein, adsorption isotherms of Pb(ii) and Cu(ii) ions on treated sea mango fruit in both single-compound and binary systems were experimentally realized at different temperatures in the range of 30-50 °C. Experimental results show that adsorption of Pb(ii) was more as compared to that of Cu(ii) ions; however, for both ions, a significant reduction in the adsorption capacity was observed in the binary system as compared to that in the single-compound systems. Moreover, under all the investigated conditions, adsorption seems to be promoted by an increase in temperature. To understand and interpret the experimental evidences, the Hill and competitive Hill models developed on the basis of the grand canonical ensemble were applied for the analysis of adsorption equilibrium data. These models contain some physicochemical parameters that allow an exhaustive analysis of the dynamics of single-compound and binary adsorptions. Based on the fitting results, in particular, through the evaluation of the number of ions bonded per site (n and ni), it was found that lead and copper ions interacted by inclined and horizontal positions on treated sea mango in single-compound and binary systems, respectively. In addition, based on the same parameters, a significant interaction between ions was retrieved. A study focused on the saturation adsorption capacity in single-compound and binary systems affirmed that the adsorbent was more selective for lead than for copper. The reduction of the adsorbed capacity ratio between the binary and single-compound systems (i.e. Qb/Qs) explained and confirmed that an inhibition effect between copper and lead ions at the same receptor site occurred. Finally, based on the energetic investigations, it was deduced that the adsorption energy represented the dominant factor promoting the greater adsorption of lead than that of copper in both systems.

  15. Copper Nanoparticle/Multiwalled Carbon Nanotube Composite Films with High Electrical Conductivity and Fatigue Resistance Fabricated via Flash Light Sintering.

    Science.gov (United States)

    Hwang, Hyun-Jun; Joo, Sung-Jun; Kim, Hak-Sung

    2015-11-18

    In this work, multiwalled carbon nanotubes (MWNTs) were employed to improve the conductivity and fatigue resistance of flash light sintered copper nanoparticle (NP) ink films. The effect of CNT weight fraction on the flash light sintering and the fatigue characteristics of Cu NP/CNT composite films were investigated. The effect of carbon nanotube length was also studied with regard to enhancing the conductivity and fatigue resistance of flash light sintered Cu NP/CNT composite films. The flash light irradiation energy was optimized to obtain high conductivity Cu NP/CNT composite films. Cu NP/CNT composite films fabricated via optimized flash light irradiation had the lowest resistivity (7.86 μΩ·cm), which was only 4.6 times higher than that of bulk Cu films (1.68 μΩ·cm). It was also demonstrated that Cu NP/CNT composite films had better durability and environmental stability than those of Cu NPs only.

  16. Complete genome sequence of a copper-resistant bacterium from the citrus phyllosphere, #Stenotrophomonas# sp. strain LM091, obtained using long-read technology

    OpenAIRE

    Richard, Damien; Boyer, Claudine; Lefeuvre, Pierre; Pruvost, Olivier

    2016-01-01

    The Stenotrophomonas genus shows great adaptive potential including resistance to multiple antimicrobials, opportunistic pathogenicity, and production of numerous secondary metabolites. Using long-read technology, we report the sequence of a plant-associated Stenotrophomonas strain originating from the citrus phyllosphere that displays a copper resistance phenotype.(Résumé d'auteur)

  17. Complete Genome Sequence of a Copper-Resistant Bacterium from the Citrus Phyllosphere, Stenotrophomonas sp. Strain LM091, Obtained Using Long-Read Technology

    Science.gov (United States)

    Richard, Damien; Boyer, Claudine; Lefeuvre, Pierre

    2016-01-01

    The Stenotrophomonas genus shows great adaptive potential including resistance to multiple antimicrobials, opportunistic pathogenicity, and production of numerous secondary metabolites. Using long-read technology, we report the sequence of a plant-associated Stenotrophomonas strain originating from the citrus phyllosphere that displays a copper resistance phenotype. PMID:27979933

  18. Evaluation of EUV resist performance below 20nm CD using helium ion lithography

    NARCIS (Netherlands)

    Maas, D.J.; Veldhoven, E. van; Langen-Suurling, A. van; Alkemade, P.F.A.; Wuister, S.; Hoefnagels, R.; Verspaget, C.; Meessen, J.; Fliervoet, T.

    2014-01-01

    For the introduction of EUV lithography, development of high performance EUV resists is of key importance. This development involves studies into resist sensitivity, resolving power and pattern uniformity. We have used a sub-nanometer-sized 30 keV helium ion beam to expose chemically amplified (CAR)

  19. Adsorption characteristics of copper, lead, zinc and cadmium ions by tourmaline

    Institute of Scientific and Technical Information of China (English)

    JIANG Kan; SUN Tie-heng; SUN Li-na; LI Hai-bo

    2006-01-01

    The adsorption characteristics of heavy metals: Cu(Ⅱ), Pb(Ⅱ), Zn(Ⅱ) and Cd(Ⅱ) ions on tourmaline were studied. Adsorption equilibrium was established. The adsorption isotherms of all the four metal ions followed well Langmuir equation. Tourmaline was found to remove heavy metal ions efficiently fiom aqueous solution with selectivity in the order of Pb(Ⅱ)>Cu(Ⅱ)>Cd(Ⅱ)>Zn(Ⅱ).The adsorption of metal ions by tourmaline increased with the initial concentration of metal ions increasing in the medium.Tourmaline could also increase pH value of metal solution. Themaximum heavy metal ions adsorbed by tourmaline was found to be 78.86, 154.08, 67.25, and 66.67 mg/g for Cu(Ⅱ), Pb(Ⅱ), Zn(Ⅱ) and Cd(Ⅱ), respectively. The temperature (25-55℃) had a small effect on the adsorption capacity of tourmaline. Competitive adsorption of Cu(Ⅱ), Pb(Ⅱ), Zn(Ⅱ) and Cd(Ⅱ) ions was also studied. The adsorption capacity of tourmaline for single metal decreased in the order of Pb>Cu>Zn>Cd and inhibition dominance observed in two metal systems was Pb>Cu, Pb>Zn, Pb>Cd, Cu>Zn, Cu>Cd, and Cd>Zn.

  20. Effects of chlortetracycline and copper supplementation on the prevalence, distribution, and quantity of antimicrobial resistance genes in the fecal metagenome of weaned pigs.

    Science.gov (United States)

    Agga, Getahun E; Scott, H Morgan; Vinasco, Javier; Nagaraja, T G; Amachawadi, Raghavendra G; Bai, Jianfa; Norby, Bo; Renter, David G; Dritz, Steve S; Nelssen, Jim L; Tokach, Mike D

    2015-05-01

    Use of in-feed antibiotics such as chlortetracycline (CTC) in food animals is fiercely debated as a cause of antimicrobial resistance in human pathogens; as a result, alternatives to antibiotics such as heavy metals have been proposed. We used a total community DNA approach to experimentally investigate the effects of CTC and copper supplementation on the presence and quantity of antimicrobial resistance elements in the gut microbial ecology of pigs. Total community DNA was extracted from 569 fecal samples collected weekly over a 6-week period from groups of 5 pigs housed in 32 pens that were randomized to receive either control, CTC, copper, or copper plus CTC regimens. Qualitative and quantitative PCR were used to detect the presence of 14 tetracycline resistance (tet) genes and to quantify gene copies of tetA, tetB, blaCMY-2 (a 3rd generation cephalosporin resistance gene), and pcoD (a copper resistance gene), respectively. The detection of tetA and tetB decreased over the subsequent sampling periods, whereas the prevalence of tetC and tetP increased. CTC and copper plus CTC supplementation increased both the prevalence and gene copy numbers of tetA, while decreasing both the prevalence and gene copies of tetB. In summary, tet gene presence was initially very diverse in the gut bacterial community of weaned pigs; thereafter, copper and CTC supplementation differentially impacted the prevalence and quantity of the various tetracycline, ceftiofur and copper resistance genes resulting in a less diverse gene population. Published by Elsevier B.V.

  1. Energy distribution of metal and noble gas ions traversing single-crystal copper films

    Science.gov (United States)

    Isakhanov, Z. A.

    2012-09-01

    A comparative investigation of the energy distribution of ions that traversed single-crystal cooper films reveals that the energy loss of channeled and nonchanneled particles depends not only on the mass but also on the radius of bombarding ions. It is established that the energy spectra of transmitted ions are highly sensitive to a change in the composition and structure of the films. From the change in these spectra, one can estimate the degree of disordering in thin films under various applied forces.

  2. Engineering Short Preorganized Peptide Sequences for Metal Ion Coordination: Copper(II) a Case Study.

    Science.gov (United States)

    Lima, L M P; Iranzo, O

    2016-01-01

    Peptides are multidentate chiral ligands capable of coordinating different metal ions. Nowadays, they can be obtained with high yield and purity, thanks to the advances on peptide/protein chemistry as well as in equipment (peptide synthesizers). Based on the identity and length of their amino acid sequences, peptides can present different degrees of flexibility and folding. Although short peptide sequences (ion coordination. Based on our experience, we present a general scheme for the design, synthesis, and characterization of these peptidic scaffolds and provide protocols for the study of their metal ion coordination properties.

  3. Resistance to antibiotics and inorganic ions in virulent bacterial strains from a hospital.

    Science.gov (United States)

    Vazquez, F; Fidalgo, S; Mendez, F J; Mendoza, M C

    1989-08-01

    Virulent strains of Staphylococcus aureus, S. epidermidis, Escherichia coli and Pseudomonas aeruginosa were studied for their resistance to antibiotics and inorganic ions, the correlation with their clinical use and the usefulness as an epidemioliogical tool. Multiresistance was common, the antibiotypes were similar to those previously reported, but characteristic resistotypes endemic of our county were found. A correlation between resistance and metal ion consumption was not detected. Staphylococci strains were susceptible to vancomycin, cephalothin and mercury chloride; S. epidermidis showed higher rates of resistance to antibiotics and lower to cadmium chloride and potassium iodine than S. aureus. E. coli strains were susceptible to new beta-lactamans; resistance to cephalothin, gentamicin, tobramycin and amikacin was less than 10%. P, aeruginosa was the species with the most multiresistance and antibiotype diversity, only ceftazidime, amikacin and imipenem had a resistance rate less than 11%. In both E. coli and P. aeruginosa resistance to all tested metals (except silver nitrate) was found although with different percentages.

  4. Potassium sorbate-A new aqueous copper corrosion inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Abelev, Esta [Department of Materials Engineering, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Starosvetsky, David [Department of Materials Engineering, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Ein-Eli, Yair [Department of Materials Engineering, Technion-Israel Institute of Technology, Haifa 32000 (Israel)]. E-mail: eineli@tx.technion.ac.il

    2007-01-01

    This work presents the novel nature of 2,4-hexadienoic acid potassium salt (potassium sorbate (KCH{sub 3}CH=CHCH=CHCO{sub 2})) as an effective copper aqueous corrosion inhibitor. The influence of pH and potassium sorbate concentration on copper corrosion in aerated sulfate and chloride solutions is reported. Degree of copper protection was found to increase with an increase in potassium sorbate concentration; an optimum concentration of this inhibitor in sulfate solutions was found to be 10 g/L. Copper is highly resistant to corrosion attacks by chloride ions in the presence of potassium sorbate. X-ray photoelectron spectroscopy (XPS) studies suggest that copper protection is achieved via the formation of a mixed layer of cuprous oxide, cupric hydroxide and copper(II)-sorbate at the metal surface.

  5. Heavy-metal resistance of a France vineyard soil bacterium, Pseudomonas mendocina strain S5.2, revealed by whole-genome sequencing.

    Science.gov (United States)

    Chong, Teik Min; Yin, Wai-Fong; Mondy, Samuel; Grandclément, Catherine; Dessaux, Yves; Chan, Kok-Gan

    2012-11-01

    Here we present the draft genome of Pseudomonas mendocina strain S5.2, possessing tolerance to a high concentration of copper. In addition to being copper resistant, the genome of P. mendocina strain S5.2 contains a number of heavy-metal-resistant genes known to confer resistance to multiple heavy-metal ions.

  6. Cadmium Sulphide-Reduced Graphene Oxide-Modified Photoelectrode-Based Photoelectrochemical Sensing Platform for Copper(II Ions.

    Directory of Open Access Journals (Sweden)

    I Ibrahim

    Full Text Available A photoelectrochemical (PEC sensor with excellent sensitivity and detection toward copper (II ions (Cu2+ was developed using a cadmium sulphide-reduced graphene oxide (CdS-rGO nanocomposite on an indium tin oxide (ITO surface, with triethanolamine (TEA used as the sacrificial electron donor. The CdS nanoparticles were initially synthesized via the aerosol-assisted chemical vapor deposition (AACVD method using cadmium acetate and thiourea as the precursors to Cd2+ and S2-, respectively. Graphene oxide (GO was then dip-coated onto the CdS electrode and sintered under an argon gas flow (50 mL/min for the reduction process. The nanostructured CdS was adhered securely to the ITO by a continuous network of rGO that also acted as an avenue to intensify the transfer of electrons from the conduction band of CdS. The photoelectrochemical results indicated that the ITO/CdS-rGO photoelectrode could facilitate broad UV-visible light absorption, which would lead to a higher and steady-state photocurrent response in the presence of TEA in 0.1 M KCl. The photocurrent decreased with an increase in the concentration of Cu2+ ions. The photoelectrode response for Cu2+ ion detection had a linear range of 0.5-120 μM, with a limit of detection (LoD of 16 nM. The proposed PEC sensor displayed ultra-sensitivity and good selectivity toward Cu2+ ion detection.

  7. Investigation on Interface Structure and Wear-resistant Properties of HVOF Sprayed Carbides Coating onto Copper Substrate

    Institute of Scientific and Technical Information of China (English)

    HOU Li-feng; ZHANG Heng-jin; WEI Ying-hui; YAN Kai; HU Lan-qing; XU Bing-she

    2004-01-01

    In this paper, we deposited carbides on copper substrate by High velocity oxy-fuel (HVOF) spraying. The structure of the coating and microstructure of the substrate-coating interface have been investigated by means of scanning electron microscope (SEM) and transmission electron microscopy (TEM). We observed the worn surface of the coating and investigated the wear mechanism. The results show that the microstructure of the interface between HVOF sprayed coating and substrate which consists of the amorphous layers, nanocrystalls in the coating and dislocation cells in copper substrate,etc. is complex. The amorphous layers are formed from heated adhesion after rapidly cooling, while the nanocrystalls come from the fragmentation of half-molten carbides. At the same time we found that the wear-resistant properties of the WC-Co coating is better than that of Cr3C2-NiCr coating at room temperature. The early wear-resistance of the HVOF sprayed coating is poor because of the roughness of its surface or bad bond of hard composite particles. The high velocity of molten droplets is propitious to fill up the interspaces between carbides, so as to make the coating more compact and reduce its porosities, thus the wear-resistance of carbides coatings is improved.

  8. Investigation on Interface Structure and Wear-resistant Properties of HVOF Sprayed Carbides Coating onto Copper Substrate

    Institute of Scientific and Technical Information of China (English)

    HOULi-feng; ZHANGHeng-jin; WEIYing-hui; YANKai; HULan-qing; XUBing-she

    2004-01-01

    In this paper, we deposited carbides on copper substrate by High velocity oxy-fuel (HVOF) spraying. The structure of the coating and microstructure of the substrate-coating interface have been investigated by means of scanning electron microscope (SEM) and transmission electron microscopy (TEM). We observed the worn surface of the coating and investigated the wear mechanism. The results show that the microstructure of the interface between HVOF sprayed coating and substrate which consists of the amorphous layers, nanocrystalls in the coating and dislocation cells in copper substrate, etc. is complex. The amorphous layers are formed from heated adhesion after rapidly cooling, while the nanocrystalls come from the fragmentation of half-molten carbides. At the same time we found that the wear-resistant properties of the WC-Co coating is better than that of Cr3C2-NiCr coating at room temperature. The early wear-resistance of the HVOF sprayed coating is poor because of the roughness of its surface or bad bond of hard composite particles. The high velocity of molten droplets is propitious to fill up the interspaces between carbides, so as to make the coating more compact and reduce its porosities, thus the wear-resistance of carbides coatings is improved.

  9. Technical note: removal of metal ion inhibition encountered during DNA extraction and amplification of copper-preserved archaeological bone using size exclusion chromatography.

    Science.gov (United States)

    Matheson, Carney D; Marion, Travis E; Hayter, Shana; Esau, Neal; Fratpietro, Renee; Vernon, Kim K

    2009-10-01

    A novel technique for the removal of metal ions inhibiting DNA extraction and PCR of archaeological bone extracts is presented using size exclusion chromatography. Two case studies, involving copper inhibition, demonstrate the effective removal of metal ion inhibition. Light microscopy, SEM, elemental analysis, and genetic analysis were used to demonstrate the effective removal of metal ions from samples that previously exhibited molecular inhibition. This research identifies that copper can cause inhibition of DNA polymerase during DNA amplification. The use of size exclusion chromatography as an additional purification step before DNA amplification from degraded bone samples successfully removes metal ions and other inhibitors, for the analysis of archaeological bone. The biochemistry of inhibition is explored through chemical and enzymatic extraction methodology on archaeological material. We demonstrate a simple purification technique that provides a high yield of purified DNA (>95%) that can be used to address most types of inhibition commonly associated with the analysis of degraded archaeological and forensic samples. We present a new opportunity for the molecular analysis of archaeological samples preserved in the presence of metal ions, such as copper, which have previously yielded no DNA results.

  10. Neutron production from 158 GeV/c per nucleon lead ions on thin copper and lead targets in the angular range 30-135 degree

    CERN Document Server

    Silari, Marco; Birattari, C; Foglio-Para, A; Gini, L; Mitaroff, Angela; Ulrici, L

    2002-01-01

    The neutron emission from 5, 10 and 20 mm thick lead and 10 and 20 mm thick copper targets bombarded by a lead ion beam with momentum of 158 GeV/c per nucleon were measured at the CERN Super Proton Synchrotron. The neutron yield and spectral fluence per incident ion on target were measured with an extended range Bonner sphere spectrometer in the angular range 30-135 degree with respect to beam direction. Monte Carlo simulations with the FLUKA code were performed to establish a guess spectrum for the unfolding of the experimental data. The results have shown that, lacking Monte Carlo radiation transport codes dealing with ions with masses larger than 1 amu, a reasonable prediction can be carried out by scaling the result of a Monte Carlo calculation for protons by the projectile mass number to the power of 0.85-0.95 for a lead target and 0.88-1.03 for a copper target.

  11. Effects of chlortetracycline and copper on tetracyclines and copper resistance genes and microbial community during swine manure anaerobic digestion.

    Science.gov (United States)

    Wang, Rui; Chen, Meixue; Feng, Feng; Zhang, Junya; Sui, Qianwen; Tong, Juan; Wei, Yuansong; Wei, Dongbin

    2017-08-01

    As antibiotic and heavy metals are over used in the livestock industry, animal manure is a reservoir of antibiotic resistance genes (ARGs). Anaerobic digestion has been reported to have the potential to reduce ARGs. However, few studies investigated whether reduction of ARGs would be affected by different external pressures including antibiotics and heavy metals during anaerobic digestion. The purpose of this study was thus to investigate effects of both chlortetracycline (CTC) and Cu on reduction of ARGs, heavy metal resistance genes (HMRGs) and mobile genetic elements (MGEs) during the swine manure anaerobic digestion. The results showed that the predominant ARGs (tetO, tetW, tetX, tetL) could be effectively reduced (approximately 1.00 log copies/g TS) through mesophilic anaerobic digestion. Microbial community evolution was the main driver. It was interesting that Treponema might indicate the termination of anaerobic digestion and compete with ARGs host bacteria. Addition of CTC, Cu and CTC+Cu affected microbial community change and hindered removal of ARGs, especially, CTC+Cu seriously affected Treponema and ARGs during anaerobic digestion. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Ion beam analysis of copper selenide thin films prepared by chemical bath deposition

    Science.gov (United States)

    Andrade, E.; García, V. M.; Nair, P. K.; Nair, M. T. S.; Zavala, E. P.; Huerta, L.; Rocha, M. F.

    2000-03-01

    Analyses of Rutherford back scattered (RBS) 4He+-particle spectra of copper selenide thin films deposited on glass slides by chemical bath were carried out to determine the changes brought about in the thin film by annealing processes. The atomic density per unit area and composition of the films were obtained from these measurements. This analysis shows that annealing in a nitrogen atmosphere at 400°C leads to the conversion of Cu xSe thin film to Cu 2Se. Results of X-ray diffraction, optical, and electrical characteristics on the films are presented to supplement the RBS results.

  13. Effect of copper ions on voltammetric signals of aminopurines at a carbon electrode

    Directory of Open Access Journals (Sweden)

    Frantisek Jelen

    2010-12-01

    Full Text Available Electrochemical oxidations of aminopurines (adenine–Ade, 2–aminopurine, 2AP, 2,6–diaminopurine, 2,6–DAP and theircomplexes with Cu(I on carbon electrodes (pencil–PeGE wereinvestigated by means of linear sweep voltammetry (LSV andelimination voltammetry with linear scan (EVLS. We found thatthe Cu(I–purine complex was formed not only by aminopurines butalso by purine. On the other hand the complex is not formed in thecase of imidazol or cytosine. The results showed that carbonelectrodes in connection with EVLS can be an excellent prototypefor cheap and fast working sensor for aminopurines in the presenceof copper.

  14. Performance, resolving power, and radial ion distributions of a prototype nanoelectrospray ionization resistive glass atmospheric pressure ion mobility spectrometer.

    Science.gov (United States)

    Kwasnik, Mark; Fuhrer, Katrin; Gonin, Marc; Barbeau, Katherine; Fernandez, Facundo M

    2007-10-15

    In this article, we describe and characterize a novel ion mobility spectrometer constructed with monolithic resistive glass desolvation and drift regions. This instrument is equipped with switchable corona discharge and nanoelectrospray ionization sources and a Faraday plate detector. Following description of the instrument, pulsing electronics, and data acquisition system, we examine the effects of drift gas flow rate and temperature, and of the aperture grid to anode distance on the observed resolving power and sensitivity. Once optimum experimental parameters are identified, different ion gate pulse lengths, and their effect on the temporal spread of the ion packet were investigated. Resolving power ranged from an average value of 50 ms/ms for a 400-micros ion gate pulse, up to an average value of 68 ms/ms for a 100-micros ion gate pulse, and a 26-cm drift tube operated at 383 V cm(-1). Following these experiments, the radial distribution of ions in the drift region of the spectrometer was studied by using anodes of varying sizes, showing that the highest ionic density was located at the center of the drift tube. Finally, we demonstrate the applicability of this instrument to the study of small molecules of environmental relevance by analyzing a commercially available siderophore, deferoxamine mesylate, in both the free ligand and Fe-bound forms. Ion mobility experiments showed a dramatic shift to shorter drift times caused by conformational changes upon metal binding, in agreement with previous reversed-phase liquid chromatography observations.

  15. Fluorescence Quenching of Pheo-phytin-a by Copper(Ⅱ)Ions

    Institute of Scientific and Technical Information of China (English)

    HU,Mingbo; LI,Huaixiang; CHEN,Lusheng; ZHANG,Huaibin; DONG,Chuan

    2009-01-01

    A method was developed for determination of Cu(Ⅱ)ions quantitatively by measuring fluorescent intensity of pheophytin-a(Pheoa)solution.The Pheoa was obtained by de-intercalation of magnesium from the porphyrin ring of chlorophyll-a(Chla)extracted from fresh spinach leaves.Its two UV-Vis absorption peaks at 505 and 535 am in acetone solution have been observed but disappeared When the acetone solution of Pheoa was mixed with a Cu(Ⅱ)ion aqueous solution.A fluorescence quenching phenomenon was thus observed when the acetone solution of Pheoa was mixed with an aqueous solution of Cu(Ⅱ)ions.However,other physiologically relevant cations rarely caused any quenching fluorescence of Pheoa under the same experimental conditions.Kinetics of the fluorescence fading process Was investigated by measuring the effects of Cu(Ⅱ)ion concentration,reaction time and reaction temperature on the fluorescence intensity of the Pheoa acetone solution.An activation energy of(10±1)kJ·mol-1 was estimated from Arrhenius empirical relation assuming that the interaction between the Pheoa and the Cu(Ⅱ)ions was the first order reaction.The calibration graph obtained with the fluorescence Was linear over the Cu(Ⅱ)concentration range of 8.0×10-5-8.0×10-7 mol·dm-3 with a detection limit of 8.0×10-7 mool·dm-3 for Cu(Ⅱ)ion.

  16. Fabrication of new carbon paste electrodes based on gold nano-particles self-assembled to mercapto compounds as suitable ionophores for potentiometric determination of copper ions

    Directory of Open Access Journals (Sweden)

    Rasoul Pourtaghavi Talemi

    2013-12-01

    Full Text Available In the present study, we investigate the potentiometric behavior of Cu2+ carbon paste electrodes based on two mercapto compounds 2-ethylmino-5-mercapto-1,3,4-thiadiazole (EAMT and 2-acetylamino-5-mercapto-1,3,4-thiadiazole (AAMT self-assembled on gold nano-paricle (GNP as ionophore. Then, the obtained results from the modified electrodes are compared. The self-assembled ionophores exhibit a high selectivity for copper ion (Cu2+, in which the sulfur and nitrogen atoms in their structure play a significant role as the effective coordination donor site for the copper ion. Among these electrodes, the best performance was obtained with the sensor with a EAMT/graphite powder/paraffin oil weight ratio of 4.0/68/28 with 200 µL of GNP which exhibits the working concentration range of 1.6×10−9 to 6.3×10−2 M and a nernstian slope of 28.9±0.4 mVdecade−1 of copper(II activity. The detection limit of electrode was 2.9(±0.2×10−10M and potential response was pH ; in other words, it was independent across the range of 2.8–6.3. The proposed electrode presented very good selectivity and sensitivity towards the Cu2+ ions over a wide variety of cations including alkali, alkaline earth, transition and heavy metal ions. Moreover, the proposed electrode was successfully applied as an indicator electrode in the potentiometric titration of Cu(II ions with EDTA and also the potentiometric determination of copper ions in spiked water samples.

  17. Thermodynamics of the formation of complexes of copper(II) ions and glycylglycine in aqueous solutions at 298 K according to calorimetry data

    Science.gov (United States)

    Kochergina, L. A.; Emel'yanov, A. V.

    2015-04-01

    Heat effects of the interaction between glycylglycine and copper(II) nitrate solutions are measured by direct calorimetry at a [metal] : [ligand] ratio of 1 : 5 and at different pH values of the solution. The measurements are made at a temperature of 298.15 K and ionic strengths of 0.25, 0.50, and 0.75. KNO3 is used as a background electrolyte. The thermodynamic characteristics of complex formation by the peptide and copper(II) ions in aqueous solutions are determined. Standard enthalpies of the formation of complex particles in aqueous solutions are calculated.

  18. Integrated metabolomic and proteomic approaches dissect the effect of metal-resistant bacteria on maize biomass and copper uptake.

    Science.gov (United States)

    Li, Kefeng; Pidatala, Venkataramana R; Shaik, Rafi; Datta, Rupali; Ramakrishna, Wusirika

    2014-01-21

    Marginal soils arise due to various industrial and agricultural practices reducing crop productivity. Pseudomonas sp. TLC 6-6.5-4 is a free-living multiple-metal-resistant plant-growth-promoting bacteria (PGPB) isolated from Torch Lake sediment that promotes maize growth and nutrient uptake. In this study, we examined both PGPB-soil and PGPB-plant interactions. PGPB inoculation resulted in significant increase in maize biomass. Soil inoculation before sowing seeds and coating seeds with the PGPB resulted in higher copper uptake by maize compared to other methods. The PGPB-soil interaction improved phosphorus uptake by maize and led to significant decrease in organic bound copper in marginal soil and a notable increase in exchangeable copper. PGPB improved soil health based on soil enzyme activities. Metabolomic analysis of maize revealed that PGPB inoculation upregulated photosynthesis, hormone biosynthesis, and tricarboxylic acid cycle metabolites. Proteomic analysis identified upregulation of proteins related to plant development and stress response. Further, the activity of antioxidant enzymes and total phenolics decreased in plants grown in marginal soil suggesting alleviation of metal stress in presence of PGPB. The ability of PGPB to modulate interconnected biochemical pathways could be exploited to increase crop productivity in marginal soils, phytoremediation of metal contaminated soils, and organic agriculture.

  19. [Flotation spectrophotometric determination of copper on isochromatic dye ion pair with crystal violet and bromopnenol blue].

    Science.gov (United States)

    Liu, B; Chen, C; Zuo, B

    1999-02-01

    Bromophenol blue (BPB) was produced and entered into the aqueous phase when NaOH solution of pH = 10 was added to Cu(biq)2BPB by trichloromethane and isoamyl alcohol (20:1) extractive. And then CV x BPB was floated by crystal violet (CV) with benzene solution. The flotation was dissolved in ethanol and the absorbance of the solution measured at 590 nm. The sensitivity was raised because of the two dyes assistant effect. The molar absorptivity was 1.45 x 10(5) L x mol(-1) x cm(-1). Copper in the sample was separated first by extracting the Cu(biq)2BPB complex with trichloromethane and isoamyl alcohol, thus achieving a high selectivity. Beer's law was obeyd in the range of 0-0. 4 mg/L with a relative standard deviation of 3.6%. For 4.8 x 10(-8) g/mL copper solution, the recoveries were 97.8%-101.7%.

  20. ELECTRODEPOSITION OF COPPER IONS ON FIXED BED ELECTRODES: KINETIC AND HYDRODYNAMIC STUDY

    Directory of Open Access Journals (Sweden)

    L.A.M. Ruotolo

    2002-03-01

    Full Text Available The kinetic and hydrodynamic behaviour of a fixed-bed electrochemical reactor was studied in terms of current efficiency (CE and energy efficiency (EE. In the kinetic experiments the effects of fixed bed thickness (L, current density (i and initial concentration of copper (C0 were studied. In the hydrodynamic experiments the permeability (k of the electrode and the coefficient for inertial forces (c were also studied as functions of the applied current density. At low current densities and bed thicknesses greater than 1.0 cm, negative CE and EE were observed as a consequence of the dissolution of the porous matrix. At high current densities low CE and EE were observed and a powdery deposit was formed on the surface of the particles. From the results of the kinetic study bed thickness and the range of current densities employed in the hydrodynamic experiments were chosen. In these experiments the electrodeposition process continued until the whole electrode had been clogged and no more electrolyte could pass through it. The relationship between pressure drop and flow rate was well described by the Forchheimer equation. It was observed that the reduction in porosity due to copper electrodeposition causes the flow rate to decrease because of the decrease in electrode permeability, but it had no influence on current efficiency.

  1. Bioinspired, direct synthesis of aqueous CdSe quantum dots for high-sensitive copper(II) ion detection.

    Science.gov (United States)

    Bu, Xiaohai; Zhou, Yuming; He, Man; Chen, Zhenjie; Zhang, Tao

    2013-11-21

    Luminescent CdSe semiconductor quantum dots (QDs), which are coated with a denatured bovine serum albumin (dBSA) shell, have been directly synthesized via a bioinspired approach. The dBSA coated CdSe QDs are ultrasmall (d CdSe QDs. The luminescent QDs are used for copper(II) ion detection due to their highly sensitive and selective fluorescence quenching response to Cu(2+). The concentration dependence of the quenching effect can be best described by the typical Stern-Volmer equation in a linearly proportional concentration of Cu(2+) ranging from 10 nM to 7.5 μM with a detection limit of 5 nM. As confirmed by various characterization results, a possible quenching mechanism is given: Cu(2+) ions are first reduced to Cu(+) by the dBSA shell and then chemical displacement between Cu(+) and Cd(2+) is performed at the surface of the ultrasmall metallic core to impact the fluorescence performance.

  2. Reducing of internal resistance lithium ion battery using glucose addition

    Energy Technology Data Exchange (ETDEWEB)

    Salim, Andri Pratama; Hafidlullah, Noor; Purwanto, Agus, E-mail: aguspurw@gmail.com [Research Group of Battery & Advanced Material, Department of Chemical Engineering, Sebelas Maret University, Jl. Ir. Sutami 36 A Kentingan, Surakarta Indonesia 57126 (Indonesia)

    2016-02-08

    There are two indicators of battery performance, i.e : capacity and the internal resistance of battery. In this research, the affect of glucose addition to decrease the internal resistance of lithium battery was investigated. The ratio of glucose addition were varied at weight ratio 1%, 3%, and 5% and one mixtures without glucose addition. Lithium ferri phosphate (LiFePO{sub 4}), polyvinylidene fluoride (PVDF), acetylene black (AB) and glucose were materials that used in this study. Both of mixtures were mixed in the vacuum mixer until became homogeneous. The slurry was coated on an aluminium foil sheet and the coated thickness was 200 µm. The performance of battery lithium was examined by Eight Channel Battery Analyzer and the Internal resistance was examined by Internal Resistance of Battery Meter. The result from all analyzer were showed that the internal resistance reduced as well as the battery capacity. The best internal resistance value is owned by mixtures with 3wt% ratio glucose addition. It has an internal resistance value about 64 miliohm.

  3. Erythromycin- and copper-resistant Enterococcus hirae from marine sediment and co-transfer of erm(B) and tcrB to human Enterococcus faecalis.

    Science.gov (United States)

    Pasquaroli, Sonia; Di Cesare, Andrea; Vignaroli, Carla; Conti, Giulia; Citterio, Barbara; Biavasco, Francesca

    2014-09-01

    An erythromycin-, copper- and cadmium-resistant isolate of Enterococcus hirae from marine sediment was shown to harbor the plasmid pRE25 and to co-transfer erm(B) and tcrB to Enterococcus faecalis JH2-2. These data highlight the scope for antibiotic resistance selection by the marine environment through heavy metals and its possible involvement in antibiotic-resistant enterococcal infections.

  4. Ion pair formation in copper sulfate aqueous solutions at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Mendez De Leo, Lucila P. [Unidad de Actividad Quimica, Comision Nacional de Energia, Avenida del Libertador 8250, 1429 Ciudad de Buenos Aires (Argentina); Escuela de Ciencia y Tecnologia, Universidad Nacional General San Martin, Alem 3901, 1653 Villa Ballester (Argentina); Bianchi, Hugo L. [Unidad de Actividad Quimica, Comision Nacional de Energia, Avenida del Libertador 8250, 1429 Ciudad de Buenos Aires (Argentina); Escuela de Ciencia y Tecnologia, Universidad Nacional General San Martin, Alem 3901, 1653 Villa Ballester (Argentina); Fernandez-Prini, Roberto [Unidad de Actividad Quimica, Comision Nacional de Energia, Avenida del Libertador 8250, 1429 Ciudad de Buenos Aires (Argentina) and INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon II, 1428 Ciudad de Buenos Aires (Argentina)]. E-mail: rfprini@cnea.gov.ar

    2005-05-15

    Ionic association between Cu{sup 2+}(aq) and SO42-(aq) has been studied in the temperature range (298 to 473) K using a spectrophotometric technique. Experiments were designed to minimize the contribution of other protolytic equilibria in solution. The values of the ionic association equilibrium constant at different temperatures and pressures were fitted to an appropriate equation that allows the calculation of the thermodynamic quantities for states close to the saturation line. Using Bjerrum's model for ionic association evidence for two ion pair populations was obtained. The process of ion pairing is discussed and a possibility to reconcile the continuum model (Bjerrum) with molecular simulation results is suggested.

  5. Low resistance barrier layer for isolating, adhering, and passivating copper metal in semiconductor fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Weihs, Timothy P. (Baltimore, MD); Barbee, Jr., Troy W. (Palto Alto, CA)

    2002-01-01

    Cubic or metastable cubic refractory metal carbides act as barrier layers to isolate, adhere, and passivate copper in semiconductor fabrication. One or more barrier layers of the metal carbide are deposited in conjunction with copper metallizations to form a multilayer characterized by a cubic crystal structure with a strong (100) texture. Suitable barrier layer materials include refractory transition metal carbides such as vanadium carbide (VC), niobium carbide (NbC), tantalum carbide (TaC), chromium carbide (Cr.sub.3 C.sub.2), tungsten carbide (WC), and molybdenum carbide (MoC).

  6. Sulfated chitosan/PVA absorbent membrane for removal of copper and nickel ions from aqueous solutions-Fabrication and sorption studies.

    Science.gov (United States)

    Abu-Saied, M A; Wycisk, Ryszard; Abbassy, Moustafa M; El-Naim, G Abd; El-Demerdash, F; Youssef, M E; Bassuony, H; Pintauro, Peter N

    2017-06-01

    Novel absorbents for the removal of Cu(2+) and Ni(2+) ions from aqueous solutions were prepared from solution cast sulfated chitosan/polyvinyl alcohol membranes (SCS/PVA) and their properties were investigated. FTIR, SEM, XRD and TGA analyses were used to determine membrane structure. The effect of environmental parameters on absorption was studied, including pH, contact time, temperature and the initial concentration of Ni(2+) and Cu(2+) ions. Freundlich and Langmuir absorption isotherms were fitted to experimental data and a pseudo-second order rate equation was employed to model the kinetics of uptake for several copper and nickel ion concentrations. The results indicate that the affinity of an SCS/PVA membrane for Cu(2+) ions was higher than that for Ni(2+) ions. The study demonstrated that the SCS/PVA system can be utilized as highly efficient sorbents, to extract Ni(2+) and Cu(2+) from aqueous feed solutions.

  7. Fabrication of Nano-Crossbar Resistive Switching Memory Based on the Copper-Tantalum Pentoxide-Platinum Device Structure

    Science.gov (United States)

    Olga Gneri, Paula; Jardim, Marcos

    Resistive switching memory has been of interest lately not only for its simple metal-insulator-metal (MIM) structure but also for its promising ease of scalability an integration into current CMOS technologies like the Field Programmable Gate Arrays and other non-volatile memory applications. There are several resistive switching MIM combinations but under this scope of research, attention will be paid to the bipolar resistive switching characteristics and fabrication of Tantalum Pentaoxide sandwiched between platinum and copper. By changing the polarity of the voltage bias, this metal-insulator-metal (MIM) device can be switched between a high resistive state (OFF) and low resistive state (ON). The change in states is induced by an electrochemical metallization process, which causes a formation or dissolution of Cu metal filamentary paths in the Tantalum Pentaoxide insulator. There is very little thorough experimental information about the Cu-Ta 2O5-Pt switching characteristics when scaled to nanometer dimensions. In this light, the MIM structure was fabricated in a two-dimensional crossbar format. Also, with the limited available resources, a multi-spacer technique was formulated to localize the active device area in this MIM configuration to less than 20nm. This step is important in understanding the switching characteristics and reliability of this structure when scaled to nanometer dimensions.

  8. Modelling the effects of copper on soil organisms and processes using the free ion approach: towards a multi-species toxicity model.

    Science.gov (United States)

    Lofts, Stephen; Criel, Peggy; Janssen, Colin R; Lock, Koen; McGrath, Steve P; Oorts, Koen; Rooney, Corinne P; Smolders, Erik; Spurgeon, David J; Svendsen, Claus; Van Eeckhout, Hilde; Zhao, Fang-Zie

    2013-07-01

    The free ion approach has been previously used to calculate critical limit concentrations for soil metals based on point estimates of toxicity. Here, the approach was applied to dose-response data for copper effects on seven biological endpoints in each of 19 European soils. The approach was applied using the concept of an effective dose, comprising a function of the concentrations of free copper and 'protective' major cations, including H(+). A significant influence of H(+) on the toxicity of Cu(2+) was found, while the effects of other cations were inconsistent. The model could be generalised by forcing the effect of H(+) and the slope of the dose-response relationship to be equal for all endpoints. This suggests the possibility of a general bioavailability model for copper effects on organisms. Furthermore, the possibility of such a model could be explored for other cationic metals such as nickel, zinc, cadmium and lead.

  9. Preparation and copper ions adsorption properties of thiosemicarbazide chitosan from squid pens.

    Science.gov (United States)

    Lin, Yue-Cheng; Wang, Hong-Peng; Gohar, Faryal; Ullah, Muhammad Haseeb; Zhang, Xiang; Xie, Dong-Fang; Fang, Hui; Huang, Jun; Yang, Jun-Xing

    2017-02-01

    Chitosan was prepared by alkaline N-deacetylation of β-chitin from squid pens. Thiosemicarbazide group was introduced to chitosan via formaldehyde-derived linkages, and thiosemicarbazide chitosan (TSFCS) with different degrees of substitution (DS) was synthesized. The DS values of TSFCS calculated by elemental analysis were 0.19, 0.36 and 0.63. The structure of the TSFCS was confirmed by elemental analysis, FTIR, XRD, TGA and SEM. The adsorption capacity of Cu(II) ions by TSFCS showed good correlation with the DS and pH (pH range 2.2-5.8). The maximum Cu(II) ions adsorption capacity of all three TSFCS samples reached 134.0mgg(-1) at pH 3.6, but chitosan showed no adsorption at this pH. The adsorption equilibrium process of Cu(II) ions onto TSFCS was better described by the Langmuir model than the Freundlich isotherm model. Cu(II) ions adsorbed by TSFCS could be released using 0.01M Na2EDTA and the adsorption capacity could retain above 80% after five adsorption-desorption cycles. TSFCS exhibited good potential for heavy metal removal because of its high adsorption capacity at the low pH.

  10. Antioxidant properties of carnosine re-evaluated with oxidizing systems involving iron and copper ions.

    Science.gov (United States)

    Mozdzan, Monika; Szemraj, Janusz; Rysz, Jacek; Nowak, Dariusz

    2005-05-01

    Carnosine has antioxidant properties and is efficient in the treatment of chemically-induced inflammatory lesions in animals. However, some studies question its biological significance as antioxidant and show lack of protection and even pro-oxidant effect of carnosine in systems containing nickel and iron ions. The ability of carnosine to: (1) reduce Fe(3+) into Fe(2+) ions; (2) protect deoxyribose from oxidation by Fe(2+)-, Fe(3+)-, and Cu(2+)-H(2)O(2)-EDTA systems; (3) protect DNA from damage caused by Cu(2+)-, and Fe(2+)-H(2)O(2)-ascorbate systems; (4) inhibit HClO- and H(2)O(2)-peroxidase-induced luminol dependent chemiluminescence was tested in vitro. At concentration 10 mM carnosine reduced 16.6+/-0.5 nmoles of Fe(3+) into Fe(2+) ions during 20 min. incubation and added to plasma significantly increased its ferric reducing ability. Inhibition of deoxyribose oxidation by 10 mM carnosine reached 56+/-5, 40+/-11 and 30+/-11% for systems containing Fe(2+), Fe(3+) and Cu(2+) ions, respectively. The damage to DNA was decreased by 84+/-9 and 61+/-14% when Cu(2+)-, and Fe(2+)-H(2)O(2)-ascorbate systems were applied. Combination of 10 mM histidine with alanine or histidine alone (but not alanine) enhanced 1.3 and 2.3 times (Peffect on DNA. Carnosine at 10 and 20 mM decreased by more than 90% light emission from both chemiluminescent systems. It is concluded that carnosine has significant antioxidant activity especially in the presence of transition metal ions. However, hydrolysis of carnosine with subsequent histidine release may be responsible for some pro-oxidant effects.

  11. The formation of copper sulphide semiconductors inside Langmuir–Blodgett films of Cu(II) ion complexes

    NARCIS (Netherlands)

    Werkman, P.J.; Wieringa, R.H.; Schouten, A.J.

    1998-01-01

    The fabrication of layers of copper sulphide within multilayers of copper complexes of the amphiphile 4-(10,12-pentacosadiynamido methyl pyridine, by diffusion of H2S into the multilayers, was studied by UV–VIS spectroscopy. XPS measurements revealed that copper sulphides can be synthesised which di

  12. Electrical Resistance and Transport Numbers of Ion-Exchange Membranes Used in Electrodialytic Soil Remediation

    DEFF Research Database (Denmark)

    Hansen, Henrik; Ottosen, Lisbeth M.; Villumsen, Arne

    1999-01-01

    causes damage to the membrane. This work presents the result from transport number and electrical resistance measurements done on four sets of ion-exchange membranes (Ionics, Inc. CR67 HMR412 cation-exchange membranes and Ionics, Inc. AR204 SXZR anion-exchange membranes), which have been used in four......Electrodialytic soil remediation is a recently developed method to decontaminate heavy metal polluted soil using ion-exchange membranes. In this method one side of the ion-exchange membrane is in direct contact with the polluted soil. It is of great importance to know if this contact with the soil...... different electrodialytic soil remediation experiments. The experiments showed that after the use in electrodialytic soil remediation, the ion-exchange membranes had transport numbers in the same magnitude as new membranes. The electrical resistance for six membranes did not differ from that of new...

  13. H4octapa: highly stable complexation of lanthanide(III) ions and copper(II).

    Science.gov (United States)

    Kálmán, Ferenc Krisztián; Végh, Andrea; Regueiro-Figueroa, Martín; Tóth, Éva; Platas-Iglesias, Carlos; Tircsó, Gyula

    2015-03-02

    The acyclic ligand octapa(4-) (H4octapa = 6,6'-((ethane-1,2-diylbis((carboxymethyl)azanediyl))bis(methylene))dipicolinic acid) forms stable complexes with the Ln(3+) ions in aqueous solution. The stability constants determined for the complexes with La(3+), Gd(3+), and Lu(3+) using relaxometric methods are log KLaL = 20.13(7), log KGdL = 20.23(4), and log KLuL = 20.49(5) (I = 0.15 M NaCl). High stability constants were also determined for the complexes formed with divalent metal ions such as Zn(2+) and Cu(2+) (log KZnL = 18.91(3) and log KCuL = 22.08(2)). UV-visible and NMR spectroscopic studies and density functional theory (DFT) calculations point to hexadentate binding of the ligand to Zn(2+) and Cu(2+), the donor atoms of the acetate groups of the ligand remaining uncoordinated. The complexes formed with the Ln(3+) ions are nine-coordinated thanks to the octadentate binding of the ligand and the presence of a coordinated water molecule. The stability constants of the complexes formed with the Ln(3+) ions do not change significantly across the lanthanide series. A DFT investigation shows that this is the result of a subtle balance between the increased binding energies across the 4f period, which contribute to an increasing complex stability, and the parallel increase of the absolute values of the hydration free energies of the Ln(3+) ions. In the case of the [Ln(octapa)(H2O)](-) complexes the interaction between the amine nitrogen atoms of the ligand and the Ln(3+) ions is weakened along the lanthanide series, and therefore the increased electrostatic interaction does not overcome the increasing hydration energies. A detailed kinetic study of the dissociation of the [Gd(octapa)(H2O)](-) complex in the presence of Cu(2+) shows that the metal-assisted pathway is the main responsible for complex dissociation at pH 7.4 and physiological [Cu(2+)] concentration (1 μM).

  14. Effects of ion beam treatment on atomic and macroscopic adhesion of copper to different polymer materials

    Science.gov (United States)

    Zaporojtchenko, V.; Zekonyte, J.; Faupel, F.

    2007-12-01

    Low-energy ion irradiation of polymer induces different phenomena in the near surface layer, which effect strongly the metal-polymer interface formation and promotes adhesion of polymers to metals. Low-energy argon and oxygen ion beams were used to alter the chemical and physical properties of different polymers (PS (polystyrene), PαMS (poly(α-methylstyrene), BPA-PC (bisphenol-A-polycarbonate) and PMMA (poly(methyl methacrylate)), in order to understand the adhesion phenomena between a deposited Cu layer and the polymers. The resulting changes were investigated by various techniques including X-ray photoelectron spectroscopy, measurements of the metal condensation coefficient and a new technique to measure cross-linking at the polymer surface. Two types of practical adhesion strengths of Cu-polymer systems, measured using 90° peel tests, were observed: (i) peel strength increased at low ion fluences, reached a maximum and then decreased after prolonged treatment and (ii) no improvement in the peel strength on treated polymer surfaces was recorded. The improvement in the metal-polymer adhesion in the ion fluence range of 10 13-10 15 cm -2 is attributed to the creation of a large density of new adsorption sites resulting in a larger contact area and incorporation of chemically active groups that lead to increased interaction between metal and polymer by metal-oxygen-polymer species formation. XPS analysis of peeled-off surfaces showed that in most cases the failure location changed from interfacial for untreated polymers to cohesive failure in the polymer for treated surfaces. These observations and measurements of the metal condensation coefficients suggest that bonding is improved at the metal-polymer interface for all metal-polymer systems. However, the decrease in the peel strength at high ion fluences is attributed to the formation of a weak boundary layer in polymers. The correlation between sputter rate of polymers and altering in the peel strength for

  15. 氯化银浊度法测定铜电解液中氯离子%Determination of Chlorine Ion in Copper Electrolyte Using Chloride Turbidimetric Method

    Institute of Scientific and Technical Information of China (English)

    巫来富

    2012-01-01

    在丙酮存在的条件下,铜电解液中的氯离子与硝酸银反应,形成氯化银乳浊液,用铜电解液的原液(即实验中铜电解液原液没有加硝酸银的试液)作参比,于分光光度计500nm处测定其吸光度,从而得出铜电解液中氯离子的含量.%In the condition of Acetone existence,Chloride ion in Copper electrolyte reacted with Silver nitrate,forming the Silver Chloride emulsion.And then we used the initial copper electrolyte solution(i.e.,copper electrolyte solution without the addition of silver nitrate solution) as reference to determine its absorbance at 500nm in spectrophotometer.Finally,we got the content of Chloride ion in Copper electrolyte.

  16. Detection and investigation of the molecular nature of low-molecular-mass copper ions in isolated rheumatoid knee-joint synovial fluid.

    Science.gov (United States)

    Naughton, D P; Knappitt, J; Fairburn, K; Gaffney, K; Blake, D R; Grootveld, M

    1995-03-20

    Low-molecular-mass copper(II) species have been detected and quantified in ultrafiltrates (n = 7) of rheumatoid synovial fluid (SF) by a highly-sensitive HPLC-based assay system with the ability to determine Cu(II) concentrations of ultrafiltrates resulted in complexation by histidine > alanine > formate > threonine > lactate > tyrosine > phenylalanine, their effectiveness in this context being in the given order. CD spectra of Cu(II)-treated samples of intact SF exhibited absorption bands typical of copper(II)-albumin complexes, in addition to a band attributable to a low-molecular-mass histidinate complex (lambda min 610 nm). Since both albumin and histidine are potent radical scavengers, these results indicate that any .OH radical generated from bound copper ions will be 'site-specifically' scavenged. Hence, low-molecular-mass copper complexes with the ability to promote the generation of .OH radical which can then escape from the metal ion co-ordination sphere (and in turn, cause damage to critical biomolecules) appear to be absent from inflammatory SF.

  17. Immobilization of Trichosporon cutaneum R 57 Cells onto Methylcellulose/SiO2 Hybrids and Biosorption of Cadmium and Copper Ions

    Directory of Open Access Journals (Sweden)

    Georgieva N.

    2009-12-01

    Full Text Available Methylcellulose/Silica (MC/SiO2 hybrids were synthesized via poly step sol-gel method. SiO2 was included into the hybrids from two silica precursors - methyltriethoxysilane (MTES and ethyltrimethoxysilane (ETMS with different quantity of organic part-5, 20 and 50 wt.%. The filamentous yeasts Trichosporon cutaneum strain R 57 was immobilized onto the synthesized MC/SiO2 hybrids. After immobilization the hybrid materials were used in the processes of sorption of cadmium and copper ions. The obtained results of protein content analysis indicated that the amount of protein increased with increasing of MC in the hybrids. It was established that the maximal efficiency of copper and cadmium removal were observed for hybrid materials containing MTES and 50 wt.% MC - 66% and 26% respectively. For ETMS and 50 wt.% MC a high value of copper removal was 56% and for cadmium - 45% removal, respectively. FTIR analysis of free and immobilized cells with metal ions was conducted. SEM images showed successful immobilization of the yeasts cells. Second order model was employed in order to investigate the kinetics of copper and cadmium biosorption.

  18. Surface reaction of Bacillus cereus biomass and its biosorption for lead and copper ions

    Institute of Scientific and Technical Information of China (English)

    PAN Jian-hua; LIU Rui-xia; TANG Hong-xiao

    2007-01-01

    In this study, the Fourier transform infrared (FTIR) analytical technique identified the surface chemical functional groups of Bacillus cereus biomass. B. Cereus cells mainly contained carboxyl, hydroxyl, phosphate, amino, and amide functional groups. In order to explain the surface acid-base properties of aqueous B. Cereus biomass, the potentiometric titration was conducted . The computer program FITEQL 4.0 was used to perform the model calculations. The optimization results indicated that three sites-three pKas model, which assumed the cell surface to have three distinct types of surface organic functional groups based on IR analysis results, simulated the experimental results very well. Moreover, batch adsorption experiments were performed to investigate biosorption behavior of Cu (Ⅱ) and Pb (Ⅱ) ions onto the biomass. Obviously, the adsorption equilibrium data for the two ions were reasonably described by typical Langmuir isotherm.

  19. A novel method for thermodynamic study on binding of copper ion with Alzheimer's amyliod β peptide

    Institute of Scientific and Technical Information of China (English)

    BEHBEHANI G. Rezaei

    2009-01-01

    The interaction of Cu2+ with the first 16 residues of the Alzheimer's amyliod β peptide, Afl(1-16), was studied by employing isothermal titration calorimetry at pH 7.2 and 37℃ in aqueous solution. The Gholamreza Rezaei Behbehani (GRB) solvation model was used to reproduce the enthalpies of Cu2++Aβ(1-16) interaction over the whole Cu++concentrations. The binding parameters recovered from the solvation model were attributed to the structural change of Aβ(1-16) due to the metal ion interaction. It was found that there is a set of two identical and non interacting binding sites for Cu2+ ions. The molar enthalpy of binding is △H=27.895 kJ/mol. The association binding constants are 1.895 μM-1 and 1.891 μM-1 for the first and second binding sites respectively.

  20. Helium release and amorphization resistance in ion irradiated nanochannel films

    Science.gov (United States)

    Hong, Mengqing; Wang, Yongqiang; Ren, Feng; Zhang, Hongxiu; Fu, Dejun; Yang, Bing; Xiao, Xiangheng; Jiang, Changzhong

    2014-04-01

    Volumetric swelling, surface blistering, exfoliation and embrittlement partially induced by the aggregation of gas bubbles are serious problems for materials in nuclear reactors. This letter demonstrates that the “vein-like” nanochannel films possess greater He management capability and radiation tolerance. For a given fluence, the He bubble size in the nanochannel film decreases with increasing the nanochannel density. For a given nanochannel density, the bubble size increases with increasing fluence initially but levels off to a maximum value of 0.8 nm after the ion fluence reaches 2\\times10^{17}\\ \\text{ions/cm}^{2} , corresponding to He release ratio of 79% in the irradiated CrN RT films. The abundant surfaces in the nanochannel films are perfect defect sinks and thereby large sized He bubbles and supersaturated defects are less likely to be developed in these high radiation tolerant materials.

  1. Oxidative degradation of propachlor by ferrous and copper ion activated persulfate.

    Science.gov (United States)

    Liu, C S; Shih, K; Sun, C X; Wang, F

    2012-02-01

    The process of in situ chemical oxidation (ISCO) by persulfate (S(2)O(8)(2-)) can be accelerated by metal ion activation, which more effectively degrades subsurface pollutants by enhancing sulfate radical (SO(4)(-)) generation. This study compared the results of propachlor degradation by Cu(2+) and Fe(2+) activated persulfate and revealed differing degradation kinetics and mechanisms between the two types of activation system. The activation of persulfate by Fe(2+) ions generally resulted in rapid degradation in the early stage, but was accompanied by a dramatic decrease in efficiency due to the rapid depletion of Fe(2+) by the sulfate radicals generated. In contrast, the Cu(2+) activated persulfate had a longer lasting degradation effect and a proportionally greater degradation enhancement at elevated Cu(2+) concentrations. An optimal Fe(2+) concentration should be sought to activate the persulfate, as a high Fe(2+) concentration of 2.5mM or above, as was used in this study, may inhibit propachlor degradation due to the competitive consumption of sulfate radicals by the excess Fe(2+) ions. Higher temperatures (55°C compared with 30°C) resulted in enhanced metal activation, particularly with the Cu(2+) activated system. Furthermore, acidic conditions were found to be more favorable for propachlor degradation by metal activated persulfate. The ecotoxicity of degraded propachlor samples, which was indicated by average well color development (AWCD) for its microbial community activity, was confirmed to be decreased during the degradation processes with these two ions activated persulfate. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Copper amendment of agricultural soil selects for bacterial antibiotic resistance in the field

    DEFF Research Database (Denmark)

    Berg, J.; Tom-Petersen, A.; Nybroe, O.

    2005-01-01

    Aims: The objective of this study was to determine whether Cu-amendment of field plots affects the frequency of Cu resistance, and antibiotic resistance patterns in indigenous soil bacteria. Methods and Results: Soil bacteria were isolated from untreated and Cu-amended field plots. Cu......-amendment significantly increased the frequency of Cu-resistant isolates. A panel of isolates were characterized by Gram-reaction, amplified ribosomal DNA restriction analysis and resistance profiling against seven antibiotics. More than 95% of the Cu-resistant isolates were Gram-negative. Cu-resistant Gram......-negative isolates had significantly higher incidence of resistance to ampicillin, sulphanilamide and multiple (greater than or equal to3) antibiotics than Cu-sensitive Gram-negative isolates. Furthermore, Cu-resistant Gram-negative isolates from Cu-contaminated plots had significantly higher incidence of resistance...

  3. The structure and phase composition of the surface layer of the samples during the processing of VT-10 titanium alloys by copper ions

    Science.gov (United States)

    Kalashnikov, Mark P.; Fedorischeva, Marina V.; Nikonenko, Alisa V.; Bozhko, Irina A.; Sergeev, Victor P.

    2016-11-01

    The phase composition, structure and morphology of the surface of VT-10 titanium modified by copper ions have been investigated by X-ray, SEM and TEM. It has been established that there are intermetallide phases of Cu-Ti equilibrium diagram in the surface layer during the treatment of VT-10 titanium by copper ions. The modified surface layer in the cross section is divided into two layers: up to 1 µm in thickness and from 1µm up to 4.5-5.0 µm, depending on the treatment time. Two-level micro and nanoporous nanocrystalline structure was formed in the modified layer. It was found that the phase structure and the morphology of the surface layers of VT-10 alloys depend on the treatment time.

  4. Sputtering of copper atoms by keV atomic and molecular ions A comparison of experiment with analytical and computer based models

    CERN Document Server

    Gillen, D R; Goelich,

    2002-01-01

    Non-resonant multiphoton ionisation combined with quadrupole and time-of-flight analysis has been used to measure energy distributions of sputtered copper atoms. The sputtering of a polycrystalline copper target by 3.6 keV Ar sup + , N sup + and CF sub 2 sup + and 1.8 keV N sup + and CF sub 2 sup + ion bombardment at 45 deg. has been investigated. The linear collision model in the isotropic limit fails to describe the high energy tail of the energy distributions. However the TRIM.SP computer simulation has been shown to provide a good description. The results indicate that an accurate description of sputtering by low energy, molecular ions requires the use of computer simulation rather than analytical approaches. This is particularly important when considering plasma-surface interactions in plasma etching and deposition systems.

  5. EPR study of complex formation between copper (II) ions and sympathomimetic amines in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Preoteasa, E.A. [Inst. of Atomic Physics, IFIN, Bucharest (Romania); Duliu, O.G.; Grecu, V.V. [Bucharest, Univ. (Romania). Dept. of Atomic and Nuclear Physics

    1997-07-01

    The complex formation between sympathomimetic amines (SA): adrenaline (AD), noradrenaline (NA), dopamine (DA), ephedrine (ED) and p-tyramine (pTA), and Cu(II) ion in aqueous solution has been studied by X-band EPR at room temperature. Excepting pTA, all investigated SA yielded two types of complexes in different pH domains. All complexes consistent with a ligand fields having a distorted octahedral symmetry, i.e., hexacoordination of Cu(II). The covalence coefficient calculated from the isotropic g and A values has shown strong ionic sigma-type ligand bonds. A structural model with the Cu(II) ion bound by four catecholic O(hydroxy) atoms for the low pH complexes of AD, NA and DA is proposed. For the high pH complexes of the former compounds as well as for both Ed complexes, the authors suppose Cu(II) bound by two N (amino) and two O (hydroxy) atoms. The spectra are consistent to water binding on the longitudinal octahedron axis in all compounds excepting the high pH complex of Ed, where OH2- ions are bound. Possible implications for the SA-cell receptors interactions are discussed.

  6. Effect of calcium-ion implantation on the corrosion resistance and biocompatibility of titanium.

    Science.gov (United States)

    Krupa, D; Baszkiewicz, J; Kozubowski, J A; Barcz, A; Sobczak, J W; Bilińiski, A; Lewandowska-Szumieł, M D; Rajchel, B

    2001-08-01

    This work presents data on the structure and corrosion resistance of titanium after calcium-ion implantation with a dose of 10(17) Ca+/cm2. The ion energy was 25 keV. Transmission electron microscopy was used to investigate the microstructure of the implanted layer. The chemical composition of the surface layer was examined by XPS and SIMS. The corrosion resistance was examined by electrochemical methods in a simulated body fluid (SBF) at a temperature of 37 degrees C. Biocompatibility tests in vitro were performed in a culture of human derived bone cells (HDBC) in direct contact with the materials tested. Both, the viability of the cells determined by an XTT assay and activity of the cells evaluated by alkaline phosphatase activity measurements in contact with implanted and non-implanted titanium samples were detected. The morphology of the cells spread on the surface of the materials examined was also observed. The results confirmed the biocompatibility of both calcium-ion-implanted and non-implanted titanium under the conditions of the experiment. As shown by TEM results, the surface layer formed during calcium-ion implantation was amorphous. The results of electrochemical examinations indicate that calcium-ion implantation increases the corrosion resistance, but only under stationary conditions; during anodic polarization the calcium-ion-implanted samples undergo pitting corrosion. The breakdown potential is high (2.7-3 V).

  7. Comparison of Wear Resistance Mechanisms of Die Steel Implanted with C and mo Ions

    Science.gov (United States)

    Cheng, M. F.; Yang, J. H.; Luo, X. D.; Zhang, T. H.

    Mo and C ions extracted from a metal vapor vacuum arc ion source were implanted into the surface of die steel (H13) to compare the wear resistance mechanisms of the implanted samples, respectively. The concentration depth profiles of implanted ions were measured using Rutherford backscattering spectroscopy and calculated by a code called TRIDYN. The structures of the implanted steel were observed by X-ray photoelectron spectroscopy and grazing-angle X-ray diffraction, respectively. It was found that the conventional heat-treated H13 steel could not be further hardened by the subsequent implanted C ions, and the thickness of the implanted layer was not an important factor for the Mo and C ion implantation to improve the wear resistance of the H13 steel. Mo ion implantation could obviously improve the wear resistance of the steel at an extraction voltage of 48 kV and a dose of 5 × 1017cm-2 due to formation of a modification layer of little oxidation with Mo2C in the implanted surface.

  8. Effect of phosphorus-ion implantation on the corrosion resistance and biocompatibility of titanium.

    Science.gov (United States)

    Krupa, D; Baszkiewicz, J; Kozubowski, J A; Barcz, A; Sobczak, J W; Biliński, A; Lewandowska-Szumieł, M; Rajchel, B

    2002-08-01

    This work presents data on the structure and corrosion resistance of titanium after phosphorus-ion implantation with a dose of 10(17)P/cm2. The ion energy was 25keV. Transmission electron microscopy was used to investigate the microstructure of the implanted layer. The chemical composition of the surface layer was examined by X-ray photoelectron spectroscopy and secondary ion mass spectrometry. The corrosion resistance was examined by electrochemical methods in a simulated body fluid at a temperature of 37 C. Biocompatibility tests in vitro were performed in a culture of human derived bone cells in direct contact with the materials tested. Both, the viability of the cells determined by an XTT assay and activity of the cells evaluated by alkaline phosphatase activity measurements in contact with implanted and non-implanted titanium samples were detected. The morphology of the cells spread on the surface of the materials examined was also observed. The results confirmed the biocompatibility of both phosphorus-ion-implanted and non-implanted titanium under the conditions of the experiment. As shown by transmission electron microscope results, the surface layer formed during phosphorus-ion implantation was amorphous. The results of electrochemical examinations indicate that phosphorus-ion implantation increases the corrosion resistance after short-term as well as long-term exposures.

  9. Characterisation and Optical Studies of Copper Oxide Nanostructures Doped with Lanthanum Ions

    Directory of Open Access Journals (Sweden)

    Varughese G.

    2014-12-01

    Full Text Available Copper Oxide is an extensively studied group II-VI semiconductor with optical properties. It exhibits a wide variety of morphologies in the nano regime that can be grown by tuning the growth habit of the CuO crystal. CuO nano materials with an average particle size of 15-27 nm are synthesized by chemical route. XRD, SEM, FTIR UV-Vis and EDS characterize the samples. The percentage of doping material is confirmed from the EDS spectra. The average crystal size of the prepared CuO: La nanopowder is determined by XRD. The UV absorption spectra revealed the absorption edge at wavelength 389 nm indicating the smaller size of CuO:La nano particle. The optical direct band gap energy of doped CuO nanoparticle is found to be in the range 3.149 eV. The increasing red shift with decreasing particle size suggests that the defects responsible for the intra gap states are primarily surface defect. The La doped CuO is highly effective and can significantly enhance the photo catalytic degradation.

  10. Removal of copper (II) from aqueous solutions by flotation using polyaluminum chloride silicate (PAX-XL60 S) as coagulant and carbonate ion as activator.

    Science.gov (United States)

    Ghazy, S E; Mahmoud, I A; Ragab, A H

    2006-01-01

    Flotation is a separation technology for removing toxic heavy metal ions from aqueous solutions. Here a simple and rapid flotation procedure is presented for the removal of copper(II) from aqueous solutions. It is based on the use of polyaluminum chloride silicate (PAX-XL60 S) as coagulant and flocculent, carbonate ion as activator and oleic acid (HOL) as surfactant. Both ion and precipitate flotation are included depending on the solution pH. Ion and precipitate flotation in the aqueous HOL-PAX-XL60 S-Cu2+-CO3(2-) system gave powerful preferential removal of Cu2+ (F -100%) over the HOL-PAX-XL60 S-Cu2+ system containing no CO3(2+) ion (F approximately 86%). The role of CO3(2-) ion is also evident from decreasing the dose of PAX-XL60 S from 700 mg l(-1) to 200 mg l(-1). The other parameters, influencing the flotation process, namely: metal ion, surfactant and PAX-XL60 S concentrations, ionic strength, temperature and foreign ions were examined. Moreover, the procedure was successfully applied to recover Cu2+ ions from different volumes up to 11 and from natural water samples.

  11. Copper ion-mediated liposomal encapsulation of mitoxantrone: the role of anions in drug loading, retention and release.

    Science.gov (United States)

    Li, Chunlei; Cui, Jingxia; Li, Yingui; Wang, Caixia; Li, Yanhui; Zhang, Lan; Zhang, Li; Guo, Wenmin; Wang, Jinxu; Zhang, Hongwu; Hao, Yanli; Wang, Yongli

    2008-08-01

    Besides pH gradient, other transmembrane gradients such as metal ion gradient could be also employed to load drugs into liposomes. In pH gradient method, anions have an important role since they could form specific aggregates with drugs, and then affect drug release kinetics from vesicles. To explore the role of anions in metal ion gradient method, copper ion-mediated mitoxantrone (MIT) loading was investigated systematically. When empty liposomes exhibiting a transmembrane copper ion gradient (300 mM) were mixed with MIT in a molar ratio of 0.2:1, after 5 min incubation at 60 degrees C, >95% MIT could be loaded into vesicles and the encapsulation was stable, regardless of the kinds of anions and initial intraliposomal pH values. The encapsulation ratio decreased with increased MIT/lipid molar ratio. But even when the molar ratio increased to 0.4, >90% encapsulation could still be achieved. In the presence of nigericin and ammonium, the drug loading profiles were affected to different degree with respect to both drug loading rate and encapsulation ratio. Relative to CuSO(4)-containing systems, CuCl(2) mediated MIT loading was unstable. Both nigericin and ammonium could alter the absorption spectra of liposomal MITs loaded with CuSO(4) gradient. In vitro release studies were performed in glucose/histidine buffer and in 50% human plasma using a dialysis method. In both of release media, CuCl(2)-containing vesicles displayed rapid release kinetics in comparison with CuSO(4) systems; and during the experiment period, MIT was lost from the vesicles continuously. When the formulations were injected into BDF1 mice at a dose of 4 mg/kg, all the liposomal formulations exhibited enhanced blood circulation time, with half-life values of 6.8-7.2h, significantly compared to the rapid clearance of free-MIT. In L1210 ascitic model, CuCl(2) formulation was more therapeutically active than CuSO(4) formulation. At a dose of 6 mg/kg, the treatment with CuCl(2) formulation resulted in

  12. Adsorption Treatment of Copper Ion and Corrosive Sulfur in Transformer Oil%变压器油中腐蚀性硫与铜离子综合处理研究

    Institute of Scientific and Technical Information of China (English)

    万涛; 周舟; 冯兵; 钱晖; 何铁祥

    2016-01-01

    Corrosive sulfur and copper ion often exist in transformer oils. It is extremely dangerous to the safety and stability operation of transformers. In view of this technical problem, we used an effective adsorbent to remove the corrosive sulfur and copper ion. The results show that after adsorption treatment for 84 h, the copper ion decreases from 1.2 mg/kg to 0.2 mg/kg, the dielectric loss factor decreases from 1.57% to 0.057%, the volume resistivity increases from 3.6 × 1010Ω·m to 1.96 × 1011Ω·m, the total sulfur decreases from 550.1 mg/kg to 380.8 mg/kg, and the corrosive sulfur decreases from 51.6 mg/L to 18.1 mg/L. The insulation resistance of transformer winding increases about three times, and the absorp-tion ratio return to normal. Moreover, the treatment process has no harmful effect to the antioxidant T501 content, water, interfacial tension acid value, and breakdown voltage.%变压器油中存在腐蚀性硫和铜离子会严重威胁变压器的安全稳定运行.针对腐蚀性硫和铜离子综合治理这一技术难题,采用吸附法对变压器油进行脱除处理.结果表明:经过84 h吸附处理,油中铜离子含量从1.2 mg/kg降至0.2 mg/kg,介质损耗因数从1.57%降至0.057%,体积电阻率从3.6 × 1010Ω·m升至1.96 × 1012Ω·m,总硫含量从550.1 mg/kg降至380.8 mg/kg,腐蚀性硫含量从51.6 mg/L降至18.1 mg/L.绕组绝缘电阻提高约3倍,吸收比恢复正常.处理过程对抗氧剂T501含量、水分、酸值、界面张力和击穿电压没有不良影响.

  13. Binding of transition metal ions [cobalt, copper, nickel and zinc] with furanyl-, thiophenyl-, pyrrolyl-, salicylyl- and pyridyl-derived cephalexins as potent antibacterial agents.

    Science.gov (United States)

    Chohan, Zahid H; Pervez, Humayun; Khan, Khalid Mohammed; Rauf, A; Supuran, Claudiu T

    2004-02-01

    A method is described for the preparation of novel cephalexin-derived furanyl-, thiophenyl-, pyrrolyl-, salicylyl- and pyridyl-containing compounds showing potent antibacterial activity. The binding of these newly synthesized antibacterial agents with metal ions such as cobalt(II), copper(II), nickel(II) and zinc(II) has been studied and their inhibitory properties against various bacterial species such as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae are also reported. These results suggest that metal ions to possess an important role in the designing of metal-based antibacterials and that such complexes are more effective against infectious diseases compared to the uncomplexed drugs.

  14. Oxygen and hydrogen peroxide reduction catalyses in neutral aqueous media using copper ion loaded glassy carbon electrode electrolyzed in ammonium carbamate solution

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Hiroaki; Yamazaki, Haruhito [Department of Materials Science and Engineering, Graduate School of Engineering, Saitama Institute of Technology, 1690 Fusaiji Fukaya, Saitama 369-0293 (Japan); Wang, Xiuyun [School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, Liaoning, 114051 (China); Uchiyama, Shunichi [Department of Materials Science and Engineering, Graduate School of Engineering, Saitama Institute of Technology, 1690 Fusaiji Fukaya, Saitama 369-0293 (Japan)], E-mail: uchiyama@sit.ac.jp

    2009-01-30

    An aminated glassy carbon electrode (AGCE) can be obtained by the electrode oxidation of glassy carbon electrode in ammonium carbamate solution. In the cyclic voltammetric experiments, the electrode reduction of the dissolved oxygen began from -0.15 V vs. Ag/AgCl in neutral aqueous media when the aminated glassy carbon electrode was used as a working electrode although it began from -0.40 V vs. Ag/AgCl when a polished GCE was used. The nitrogen containing groups introduced by the electrode oxidation of carbamic acid must be related with the acceleration of the electron transfer rate of oxygen. Moreover, the new reduction wave of the dissolved oxygen appeared at +0.15 V vs. Ag/AgCl when copper (II) ion was coordinated to AGCE surface. This reduction potential of oxygen coincided with that of copper (II) ion and this fact suggests that the coordinated copper ion to the aminated carbon surface works as a redox mediator of oxygen. The reduction product of oxygen was monitored by rotating platinum ring - aminated glassy carbon disk electrode, and it was found that most of oxygen was reduced to water in a potential range negative than -0.4 V vs. Ag/AgCl. By using AGCE, it was recognized that the catalytic reduction of hydrogen peroxide was also taken place as well as oxygen reduction.

  15. Polyacrylamide-phytic acid-polydopamine conducting porous hydrogel for rapid detection and removal of copper (II) ions.

    Science.gov (United States)

    Zhao, Zhen; Chen, Hongda; Zhang, Hua; Ma, Lina; Wang, Zhenxin

    2017-05-15

    In this work, a conducting porous polymer hydrogel-based electrochemical sensor has been developed for rapid detection of copper (II) ions (Cu(2+)). The polymer (termed as PAAM/PA/PDA) hydrogel is prepared through multi-interactions of the monomers dopamine (DA), acrylamide (AAM) and phytic acid (PA) under mild ambient conditions: the AAM polymerizes through free-radical polymerization, DA occurs poly coupling reaction, and PA crosslinks polydopamine (PDA) and polyacrylamide (PAAM) by hydrogen bonds. The three dimensional (3D) network nanostructured PAAM/PA/PDA hydrogel not only provides a large surface area for increasing the amount of immobilized molecules/ions, but also exhibits a good conductivity. The PAAM/PA/PDA hydrogel-based electrochemical sensor exhibits a low detection limit (1nmolL(-)(1), S/N=3) and wide linear range (from 1nmolL(-)(1) to 1µmolL(-1)) for Cu(2+) detection in aqueous samples. Furthermore, the Cu(2+) can be sensitively detected by the electrochemical sensor in different sample matrices, indicating that the electrochemical sensor could be used to monitor Cu(2+) with reasonable assay performance in practical samples. The PAAM/PA/PDA hydrogel also exhibits a good capacity to remove Cu(2+)(231.36±4.70mgg(-1)), which is superior to those of other adsorption materials reported in the literature. The facile synthesized PAAM/PA/PDA hydrogel provides a novel and regenerable platform for monitoring and removing Cu(2+) in real samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Copper and Zinc Ions Specifically Promote Nonamyloid Aggregation of the Highly Stable Human γ-D Crystallin.

    Science.gov (United States)

    Quintanar, Liliana; Domínguez-Calva, José A; Serebryany, Eugene; Rivillas-Acevedo, Lina; Haase-Pettingell, Cameron; Amero, Carlos; King, Jonathan A

    2016-01-15

    Cataract is the leading cause of blindness in the world. It results from aggregation of eye lens proteins into high-molecular-weight complexes, causing light scattering and lens opacity. Copper and zinc concentrations in cataractous lens are increased significantly relative to a healthy lens, and a variety of experimental and epidemiological studies implicate metals as potential etiological agents for cataract. The natively monomeric, β-sheet rich human γD (HγD) crystallin is one of the more abundant proteins in the core of the lens. It is also one of the most thermodynamically stable proteins in the human body. Surprisingly, we found that both Cu(II) and Zn(II) ions induced rapid, nonamyloid aggregation of HγD, forming high-molecular-weight light-scattering aggregates. Unlike Zn(II), Cu(II) also substantially decreased the thermal stability of HγD and promoted the formation of disulfide-bridged dimers, suggesting distinct aggregation mechanisms. In both cases, however, metal-induced aggregation depended strongly on temperature and was suppressed by the human lens chaperone αB-crystallin (HαB), implicating partially folded intermediates in the aggregation process. Consistently, distinct site-specific interactions of Cu(II) and Zn(II) ions with the protein and conformational changes in specific hinge regions were identified by nuclear magnetic resonance. This study provides insights into the mechanisms of metal-induced aggregation of one of the more stable proteins in the human body, and it reveals a novel and unexplored bioinorganic facet of cataract disease.

  17. Oscillatory Changes of the Heterogeneous Reactive Layer Detected with the Motional Resistance during the Galvanostatic Deposition of Copper in Sulfuric Solution.

    Science.gov (United States)

    Cuenca, Alejandro; Agrisuelas, Jerónimo; García-Jareño, José J; Vicente, Francisco

    2015-11-24

    Metallic copper was galvanostatically deposited on quartz|gold resonant electrodes by applying a constant current in a 0.5 M CuSO4/0.1 M H2SO4 aqueous solution. Galvanostatic copper deposition is one of the best methodologies to calibrate the electrochemical quartz crystal microbalances (EQCM), a gravimetric sensor to evaluate changes in mass during the electrochemical reactions through the Sauerbrey equation. The simultaneous measurement of mass, current density, and motional resistance by an EQCM with motional resistance monitoring allows us to characterize the processes occurring on the electrode surface and at the interfacial regions with unprecedented detail. During the galvanostatic copper deposition, Cu(H2O)4(OH)2 is accumulated close to the copper surface, generating a passive layer. This passive layer can act as Cu(2+) reservoir for the Cu(2+) → Cu process since the copper deposition is not affected. The analysis of motional resistance evolution in different experimental conditions reveals that the passive layer is formed by the reaction of oxidizing agents generated at the counter electrode with the metallic copper surface. The simplistic Cu(2+) → Cu process is completed with a more detailed mechanism, which includes the passive layer formation/dissolution and the transport of species from the counter electrode surface (Pt) to the working electrode surface. The results further support the calibration procedure of EQCM by the galvanostatic deposition of copper in sulfuric solutions. However, we suggest applying high current densities, separating the counter electrode and quartz|gold resonant electrode about 0.5 cm, and keeping oxygen in solution for the EQCM calibration. Moreover, the better interval time to calculate the Sauerbrey's constant from charge and resonant frequency data is between 150 and 300 s.

  18. Simple PEG Modification of DNA Aptamer Based on Copper Ion Coordination for Tumor Targeting.

    OpenAIRE

    Takafuji, Yoshimasa; Jo, Jun-ichiro; Tabata, Yasuhiko

    2011-01-01

    A simple modification of a DNA aptamer with poly(ethylene glycol) (PEG) based on metal coordination was developed. N, N-bis(carboxymethyl)-L-lysine (NTA) of a metal chelate residue was chemically introduced to one terminus of PEG. The NTA-introduced PEG (PEG-NTA) chelated Cu(2+) ions form a Cu(2+)-chelated PEG (PEG-Cu). When PEG-Cu was mixed with a DNA aptamer of anti-tumor activity (AS1411) in aqueous solution, a complex of PEG-Cu and AS1411 based on metal coordination was formed. The comple...

  19. Use of Composite Sorbents for the Removal of Copper (II ions from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Rebecca Oyedoyin Adeeyo

    2015-01-01

    Full Text Available Composite adsorbents are synthesized from two or more materials with different chemical and physical properties in order to increase their selectivity and the reusability. Researchers have developed and applied several novel composite materials for enhancing the removal of heavy metal. In this review, extensive list of composites developed via advanced technologies with specified characteristics for the removal of Cu (II ion are discussed. Emphases on their adsorption capacities, reusability, desorption and regeneration with improved mechanical strengths are presented. Conclusively, prospects and other challenges to be checked and addressed in future are outlined.

  20. Determination of trace labile copper in environmental waters by magnetic nanoparticle solid phase extraction and high-performance chelation ion chromatography.

    Science.gov (United States)

    Wei, Z; Sandron, S; Townsend, A T; Nesterenko, P N; Paull, B

    2015-04-01

    Cobalt magnetic nanoparticles surface functionalised with iminodiacetic acid were evaluated as a nano-particulate solid phase extraction absorbent for copper ions (Cu(2+)) from environmental water samples. Using an external magnetic field, the collector nanoparticles could be separated from the aqueous phase, and adsorbed ions simply decomplexed using dilute HNO3. Effects of pH, buffer concentration, sample and sorbent volume, extraction equilibrium time, and interfering ion concentration on extraction efficiency were investigated. Optimal conditions were then applied to the extraction of Cu(2+) ions from natural water samples, prior to their quantitation using high-performance chelation ion chromatography. The limits of detection (LOD) of the combined extraction and chromatographic method were ~0.1 ng ml(-1), based upon a 100-fold preconcentration factor (chromatographic performance; LOD=9.2 ng ml(-1) Cu(2+)), analytical linear range from 20 to 5000 ng mL(-1), and relative standard deviations=4.9% (c=1000 ng ml(-1), n=7). Accuracy and precision of the combined approach was verified using a certified reference standard estuarine water sample (SLEW-2) and comparison of sample determinations with sector field inductively coupled plasma mass spectrometry. Recoveries from the addition of Cu(2+) to impacted estuarine and rain water samples were 103.5% and 108.5%, respectively. Coastal seawater samples, both with and without prior UV irradiation and dissolved organic matter removal were also investigated using the new methodology. The effect of DOM concentration on copper availability was demonstrated.

  1. Mobilization of Copper ions by Flavonoids in Human Peripheral Lymphocytes Leads to Oxidative DNA Breakage: A Structure Activity Study

    Directory of Open Access Journals (Sweden)

    Hussain Arif

    2015-11-01

    Full Text Available Epidemiological studies have linked dietary consumption of plant polyphenols with lower incidence of various cancers. In particular, flavonoids (present in onion, tomato and other plant sources induce apoptosis and cytotoxicity in cancer cells. These can therefore be used as lead compounds for the synthesis of novel anticancer drugs with greater bioavailability. In the present study, we examined the chemical basis of cytotoxicity of flavonoids by studying the structure–activity relationship of myricetin (MN, fisetin (FN, quercetin (QN, kaempferol (KL and galangin (GN. Using single cell alkaline gel electrophoresis (comet assay, we established the relative efficiency of cellular DNA breakage as MN > FN > QN > KL > GN. Also, we determined that the cellular DNA breakage was the result of mobilization of chromatin-bound copper ions and the generation of reactive oxygen species. The relative DNA binding affinity order was further confirmed using molecular docking and thermodynamic studies through the interaction of flavonoids with calf thymus DNA. Our results suggest that novel anti-cancer molecules should have ortho-dihydroxy groups in B-ring and hydroxyl groups at positions 3 and 5 in the A-ring system. Additional hydroxyl groups at other positions further enhance the cellular cytotoxicity of the flavonoids.

  2. Imprint Molding of a Microfluidic Optical Cell on Thermoplastics with Reduced Surface Roughness for the Detection of Copper Ions.

    Science.gov (United States)

    Wu, Jing; Lee, Nae Yoon

    2016-01-01

    Here, we introduce a simple and facile technique for fabricating microfluidic optical cells by utilizing a micropatterned polymer mold, followed by imprinting on thermoplastic substrates. This process has reduced the surface roughness of the microchannel, making it suitable for microscale optical measurements. The micropatterned polymer mold was fabricated by first micromilling on a poly(methylmethacrylate) (PMMA) substrate, and then transferring the micropattern onto an ultraviolet (UV)-curable optical adhesive. After an anti-adhesion treatment of the polymer mold fabricated using the UV-curable optical adhesive, the polymer mold was used repeatedly for imprinting onto various thermoplastics, such as PMMA, polycarbonate (PC), and poly(ethyleneterephthalate) (PET). The roughness values for the PMMA, PC, and PET microchannels were approximately 11.3, 20.3, and 14.2 nm, respectively, as compared to those obtained by micromilling alone, which were 15.9, 76.8, and 207.5 nm, respectively. Using the imprint-molded thermoplastic optical cell, rhodamine B and copper ions were successfully quantified. The reduced roughness of the microchannel surface resulted in improved sensitivity and reduced noise, paving the way for integration of the detection module so as to realize totally integrated microdevices.

  3. Creatinine and urea biosensors based on a novel ammonium ion-selective copper-polyaniline nano-composite.

    Science.gov (United States)

    Zhybak, M; Beni, V; Vagin, M Y; Dempsey, E; Turner, A P F; Korpan, Y

    2016-03-15

    The use of a novel ammonium ion-specific copper-polyaniline nano-composite as transducer for hydrolase-based biosensors is proposed. In this work, a combination of creatinine deaminase and urease has been chosen as a model system to demonstrate the construction of urea and creatinine biosensors to illustrate the principle. Immobilisation of enzymes was shown to be a crucial step in the development of the biosensors; the use of glycerol and lactitol as stabilisers resulted in a significant improvement, especially in the case of the creatinine, of the operational stability of the biosensors (from few hours to at least 3 days). The developed biosensors exhibited high selectivity towards creatinine and urea. The sensitivity was found to be 85 ± 3.4 mAM(-1)cm(-2) for the creatinine biosensor and 112 ± 3.36 mAM(-1)cm(-2) for the urea biosensor, with apparent Michaelis-Menten constants (KM,app), obtained from the creatinine and urea calibration curves, of 0.163 mM for creatinine deaminase and 0.139 mM for urease, respectively. The biosensors responded linearly over the concentration range 1-125 µM, with a limit of detection of 0.5 µM and a response time of 15s. The performance of the biosensors in a real sample matrix, serum, was evaluated and a good correlation with standard spectrophotometric clinical laboratory techniques was found.

  4. Copper Ferrocyanide Functionalized Core-Shell Magnetic Silica Composites for the Selective Removal of Cesium Ions from Radioactive Liquid Waste.

    Science.gov (United States)

    Lee, Hyun Kyu; Yang, Da Som; Oh, Wonzin; Choi, Sang-June

    2016-06-01

    The copper ferrocyanide functionalized core-shell magnetic silica composite (mag@silica-CuFC) was prepared and was found to be easily separated from aqueous solutions by using magnetic field. The synthesized mag@silica-CuFC composite has a high sorption ability of Cs owing to its strong affinity for Cs as well as the high surface area of the supports. Cs sorption on the mag@silica-CuFC composite quickly reached the sorption equilibrium after 2 h of contact time. The effect of the presence of salts with a high concentration of up to 3.5 wt% on the efficiency of Cs sorption onto the composites was also studied. The maximum sorption ability was found to be maintained in the presence of up to 3.5 wt% of NaCl in the solution. Considering these results, the mag@silica-CuFC composite has great potential for use as an effective sorbent for the selective removal of radioactive Cs ions.

  5. Solvothermal syntheses and characterization of three new silver(I)/copper(I)-thioarsenates based on As2+/As3+ ions

    Science.gov (United States)

    Yao, Hua-Gang; Tang, Cheng-Fei; An, Yong-Lin; Ou, Zi-Jian; Wu, Guo-Hao; Lan, Pei; Zheng, Yi-Long

    2017-02-01

    Three new silver(I)/copper(I)-thioarsenates KAgAsIIS2 (1), RbCu2AsIIIS3 (2) and RbCu4AsIIIS4 (3) have been solvothermally synthesized and structurally characterized. 1 exhibits a two-dimensional anionic network built up by As-As bond connecting the left- and right-handed helical [AgS2]4- chains, and represents the first examples of thioarsenates(II). The structure of 2 consists of two kinds of helical [Cu2S3]4- chains linked by the arsenic atoms to form double layers with rubidium ions between the layers. Compound 3 is built up of infinite [Cu2S2]2- chain and layered [Cu6As2S6] linked to form a three-dimensional anionic framework, [Cu4AsS4]-, and containing channels in which the rubidium cations reside. The optical properties of 1-3 have been investigated by UV-vis spectroscopy.

  6. Polyethyleneimine-templated copper nanoclusters via ascorbic acid reduction approach as ferric ion sensor

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Jie; Ju, Yuyun; Liu, Juanjuan; Zhang, Huige [State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Chen, Xingguo, E-mail: chenxg@lzu.edu.cn [State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou 730000 (China)

    2015-01-07

    Highlights: • A new method for synthesis of the BPEI-CuNCs is established. • A facile approach for Fe{sup 3+} ion sensing by fluorescence quenching is developed. • The method for Fe{sup 3+} sensing has high sensitivity and excellent selectivity. - Abstract: In this report we reported a facile one-pot method for synthesis of water-soluble and stable fluorescent CuNCs at room temperature, in which branched polyethyleneimine (BPEI) served as capping scaffold and ascorbic acid as reducing agent. The prepared BPEI-CuNCs exhibited excellent properties such as good water-solubility, photostability and high stability toward high ionic strength. Based on the electron transfer induced fluorescence quenching mechanism, this fluorescence probe was used for the sensitive and selective determination of ferric ions (Fe{sup 3+}) in aqueous solution. The limit of detection was 340 nM in the linear range of 0.5–1000 μM, which was lower than the maximum level of Fe{sup 3+} permitted in drinking water by the U.S. Environmental Protection Agency. The method was successfully applied to the detection of Fe{sup 3+} in tap water, Yellow River water and human urine samples with the quantitative spike recoveries ranging from 95.3% to 112.0%.

  7. Self-assembly of core-satellite gold nanoparticles for colorimetric detection of copper ions.

    Science.gov (United States)

    Weng, Ziqing; Wang, Hongbin; Vongsvivut, Jitraporn; Li, Runqing; Glushenkov, Alexey M; He, Jin; Chen, Ying; Barrow, Colin J; Yang, Wenrong

    2013-11-25

    Molecule-coated nanoparticles are hybrid materials which can be engineered with novel properties. The molecular coating of metal nanoparticles can provide chemical functionality, enabling assembly of the nanoparticles that are important for applications, such as biosensing devices. Herein, we report a new self-assembly of core-satellite gold nanoparticles linked by a simple amino acid l-Cysteine for biosensing of Cu(2+). The plasmonic properties of core-satellite nano-assemblies were investigated, a new red shifted absorbance peak from about 600 to 800 nm was found, with specific wavelength depending on ratios with assembly of large and small gold nanoparticles. The spectral features obtained using surface-enhanced Raman spectroscopy (SERS) provided strong evidence for the assembly of the Cu(2+) ions to the L-Cysteine molecules leading to the successful formation of the core-satellite Cu(l-Cysteine) complex on the gold surfaces. In addition, a linear relationship between the concentration of mediating Cu(2+) and absorbance of self-assembled gold nanoparticles (GNPs) at 680 nm was obtained. These results strongly address the potential strategy for applying the functionalized GNPs as novel biosensing tools in trace detections of certain metal ions.

  8. Pseudomonas lini Strain ZBG1 Revealed Carboxylic Acid Utilization and Copper Resistance Features Required for Adaptation to Vineyard Soil Environment: A Draft Genome Analysis

    Science.gov (United States)

    Chan, Kok-Gan; Chong, Teik-Min; Adrian, Tan-Guan-Sheng; Kher, Heng Leong; Grandclément, Catherine; Faure, Denis; Yin, Wai-Fong; Dessaux, Yves; Hong, Kar-Wai

    2016-01-01

    Pseudomonas lini strain ZBG1 was isolated from the soil of vineyard in Zellenberg, France and the draft genome was reported in this study. Bioinformatics analyses of the genome revealed presence of genes encoding tartaric and malic acid utilization as well as copper resistance that correspond to the adaptation this strain in vineyard soil environment. PMID:27512520

  9. In Vitro Susceptibility of Methicillin-Resistant Staphylococcus aureus and Methicillin-Susceptible Staphylococcus aureus to a New Antimicrobial, Copper Silicate▿

    OpenAIRE

    2007-01-01

    The soluble copper silicate (CS) MIC of 100 strains of methicillin-resistant Staphylococcus aureus and 100 strains of methicillin-susceptible S. aureus (MSSA) was 175 mg Cu/liter. Bactericidal and postantibiotic effects (≥1 h) were seen at 2× MIC and 4× MIC. The frequency of mutation was

  10. Influence of the Ion Coordination Number on Cation Exchange Reactions with Copper Telluride Nanocrystals.

    Science.gov (United States)

    Tu, Renyong; Xie, Yi; Bertoni, Giovanni; Lak, Aidin; Gaspari, Roberto; Rapallo, Arnaldo; Cavalli, Andrea; Trizio, Luca De; Manna, Liberato

    2016-06-01

    Cu2-xTe nanocubes were used as starting seeds to access metal telluride nanocrystals by cation exchanges at room temperature. The coordination number of the entering cations was found to play an important role in dictating the reaction pathways. The exchanges with tetrahedrally coordinated cations (i.e., with coordination number 4), such as Cd(2+) or Hg(2+), yielded monocrystalline CdTe or HgTe nanocrystals with Cu2-xTe/CdTe or Cu2-xTe/HgTe Janus-like heterostructures as intermediates. The formation of Janus-like architectures was attributed to the high diffusion rate of the relatively small tetrahedrally coordinated cations, which could rapidly diffuse in the Cu2-xTe NCs and nucleate the CdTe (or HgTe) phase in a preferred region of the host structure. Also, with both Cd(2+) and Hg(2+) ions the exchange led to wurtzite CdTe and HgTe phases rather than the more stable zinc-blende ones, indicating that the anion framework of the starting Cu2-xTe particles could be more easily deformed to match the anion framework of the metastable wurtzite structures. As hexagonal HgTe had never been reported to date, this represents another case of metastable new phases that can only be accessed by cation exchange. On the other hand, the exchanges involving octahedrally coordinated ions (i.e., with coordination number 6), such as Pb(2+) or Sn(2+), yielded rock-salt polycrystalline PbTe or SnTe nanocrystals with Cu2-xTe@PbTe or Cu2-xTe@SnTe core@shell architectures at the early stages of the exchange process. In this case, the octahedrally coordinated ions are probably too large to diffuse easily through the Cu2-xTe structure: their limited diffusion rate restricts their initial reaction to the surface of the nanocrystals, where cation exchange is initiated unselectively, leading to core@shell architectures. Interestingly, these heterostructures were found to be metastable as they evolved to stable Janus-like architectures if annealed at 200 °C under vacuum.

  11. MODIFICATION OF KELUD VOLCANIC ASH 2014 AS SELECTIVE ADSORBENT MATERIAL FOR COPPER(II METAL ION

    Directory of Open Access Journals (Sweden)

    Susila Kristianingrum

    2017-01-01

      This research aims to prepare an adsorbent from Kelud volcanic ash for better Cu(II adsorption efficiency than Kiesel gel 60G E'Merck. Adsorbent synthesis was done by dissolving 6 grams of volcanic ash activated 700oC 4 hours and washed with HCl 0.1 M into 200 ml of 3M sodium hydroxide with stirring and heating of 100 °C for 1 hour. The filtrate sodium silicate was then neutralized using sulfuric acid. The mixture was allowed to stand for 24 hours then filtered and washed with aquaDM, then dried and crushed. The procedure is repeated for nitric acid, acetic acid and formic acid with a contact time of 24 hours. The products were then characterized using FTIR and XRD, subsequently determined acidity, moisture content, and tested for its adsorption of the ion Cu (II with AAS. The results showed that the type of acid that produced highest rendemen is AK-H2SO4-3M ie 36.93%, acidity of the adsorbent silica gel synthesized similar to Kiesel gel 60G E'Merck ie adsorbent AK-CH3COOH-3M and the water content of the silica gel adsorbent synthesized similar to Kiesel gel 60G E'Merck ie adsorbent AK-H2SO4-2 M. The character of the functional groups of silica gel synthesized all have similarities with Kiesel gel 60G E'Merck as a comparison. Qualitative analysis by XRD for all modified adsorbent showed a dominant peak of SiO2 except adsorbent AK-H2SO4 amorphous and chemical bonds with FTIR indicates that it has formed a bond of Si-O-Si and Si-OH. The optimum adsorption efficiency of the metal ions Cu(II obtained from AK-H2SO4-5M adsorbent that is equal to 93.2617% and the optimum adsorption capacity of the Cu(II metal ions was obtained from the adsorbent AK-CH3COOH-3M is equal to 2.4919 mg/ g.   Keywords: adsorbents, silica gel, adsorption, kelud volcanic ash

  12. In vivo detection of copper ions by magnetic resonance imaging using a prion-based contrast agent.

    Science.gov (United States)

    Makino, Satoshi; Umemoto, Tomohiro; Yamada, Hiroshi; Yezdimer, Eric M; Tooyama, Ikuo

    2012-10-01

    Abnormal distributions of transition metals inside the body are potential diagnostic markers for several diseases, including Alzheimer's disease, Parkinson's disease, Wilson's disease, and cancer. In this article, we demonstrate that P57/Gd, a novel prion-based contrast agent, can selectively image tissues with excessive copper accumulation using magnetic resonance imaging (MRI). P57/Gd selectivity binds copper(II) over other physiologically relevant cations such as zinc, iron, manganese, and calcium. To simulate a metabolic copper disorder, we treated mice with an intraperitoneal injection of a CuSO(4) solution to induce a renal copper overload. The MRI signal intensities from the renal cortex and medulla of copper spiked animals that were administered P57/Gd were found to correlate with the ex vivo copper concentrations determined by inductively coupled plasma mass spectrometry.

  13. Iron sulfide attenuates the methanogenic toxicity of elemental copper and zinc oxide nanoparticles and their soluble metal ion analogs.

    Science.gov (United States)

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

    2016-04-01

    Elemental copper (Cu(0)) and zinc oxide (ZnO) nanoparticle (NP) toxicity to methanogens has been attributed to the release of soluble metal ions. Iron sulfide (FeS) partially controls the soluble concentration of heavy metals and their toxicity in aquatic environments. Heavy metals displace the Fe from FeS forming poorly soluble metal sulfides in the FeS matrix. Therefore, FeS may be expected to attenuate the NP toxicity. This work assessed FeS as an attenuator of the methanogenic toxicity of Cu(0) and ZnO NPs and their soluble salt analogs. The toxicity attenuation capacity of fine (25-75μm) and coarse (500 to 1200μm) preparations of FeS (FeS-f and FeS-c respectively) was tested in the presence of highly inhibitory concentrations of CuCl2, ZnCl2 Cu(0) and ZnO NPs. FeS-f attenuated methanogenic toxicity better than FeS-c. The results revealed that 2.5× less FeS-f than FeS-c was required to recover the methanogenic activity to 50% (activity normalized to uninhibited controls). The results also indicated that a molar FeS-f/Cu(0) NP, FeS-f/ZnO NP, FeS-f/ZnCl2, and FeS-f/CuCl2 ratio of 2.14, 2.14, 4.28, and 8.56 respectively, was necessary to recover the methanogenic activity to >75%. Displacement experiments demonstrated that CuCl2 and ZnCl2 partially displaced Fe from FeS. As a whole, the results indicate that not all the sulfide in FeS was readily available to react with the soluble Cu and Zn ions which may explain the need for a large stoichiometric excess of FeS to highly attenuate Cu and Zn toxicity. Overall, this study provides evidence that FeS attenuates the toxicity caused by Cu(0) and ZnO NPs and their soluble ion analogs to methanogens.

  14. Ultrasensitive probing of the protein resistance of PEG surfaces by secondary ion mass spectrometry

    DEFF Research Database (Denmark)

    Kingshott, P.; McArthur, S.; Thissen, H.

    2002-01-01

    The highly sensitive surface analytical techniques X-ray photoelectron spectroscopy (XPS) and time-of-flight static secondary ion mass spectrometry (ToF-SIMS) were used to test the resistance of poly(ethylene glycol) (PEG) coatings towards adsorption of lysozyme (LYS) and fibronectin (FN). PEG co...

  15. Resist and Exposure Processes for Sub-10-nm Electron and Ion Beam Lithography

    NARCIS (Netherlands)

    Sidorkin, V.A.

    2010-01-01

    The research work described in this thesis deals with studying the ultimate resolution capabilities of electron and ion beam lithography (EBL and IBL respectively) with a focus on resist and exposure processes. The aim of this research was to enlarge knowledge and improve methods on the formation of

  16. Ion channels and transporters in the development of drug resistance in cancer cells

    DEFF Research Database (Denmark)

    Hoffmann, Else Kay; Lambert, Ian Henry

    2014-01-01

    Multi-drug resistance (MDR) to chemotherapy is the major challenge in the treatment of cancer. MDR can develop by numerous mechanisms including decreased drug uptake, increased drug efflux and the failure to undergo drug-induced apoptosis. Evasion of drug-induced apoptosis through modulation of ion...

  17. Resist and Exposure Processes for Sub-10-nm Electron and Ion Beam Lithography

    NARCIS (Netherlands)

    Sidorkin, V.A.

    2010-01-01

    The research work described in this thesis deals with studying the ultimate resolution capabilities of electron and ion beam lithography (EBL and IBL respectively) with a focus on resist and exposure processes. The aim of this research was to enlarge knowledge and improve methods on the formation of

  18. Removal of copper ions from aqueous solution by calcium alginate immobilized kaolin.

    Science.gov (United States)

    Li, Yanhui; Xia, Bing; Zhao, Quansheng; Liu, Fuqiang; Zhang, Pan; Du, Qiuju; Wang, Dechang; Li, Da; Wang, Zonghua; Xia, Yanzhi

    2011-01-01

    Kaolin has been widely used as an adsorbent to remove heavy metal ions from aqueous solutions. However, the lower heavy metal adsorption capacity of kaolin limits its practical application. A novel environmental friendly material, calcium alginate immobilized kaolin (kaolin/CA), was prepared using a sol-gel method. The effects of contact time, pH, adsorbent dose, and temperature on Cu2+ adsorption by kaolin/CA were investigated. The Langmuir isotherm was used to describe the experimental adsorption, the maximum Cu2+ adsorption capacity of the kaolin/CA reached up to 53.63 mg/g. The thermodynamic studies showed that the adsorption reaction was a spontaneous and endothermic process.

  19. Removal of copper ions from aqueous solution by calcium alginate immobilized kaolin

    Institute of Scientific and Technical Information of China (English)

    Yanhui Li; Yanzhi Xia; Bing Xia; Quansheng Zhao; Fuqiang Liu; Pan Zhang; Qiuju Du; Dechang Wang; Da Li; Zonghua Wang

    2011-01-01

    Kaolin has been widely used as an adsorbent to remove heavy metal ions from aqueous solutions. However, the lower heavy metal adsorption capacity of kaolin limits its practical application. A novel environmental friendly material, calcium alginate immobilized kaolin (kaolin/CA), was prepared using a sol-gel method. The effects of contact time, pH, adsorbent dose, and temperature on Cu2+ adsorption by kaolin/CA were investigated. The Langmuir isotherm was used to describe the experimental adsorption, the maximum Cu2+ adsorption capacity of the kaolin/CA reached up to 53.63 mg/g. The thermodynamic studies showed that the adsorption reaction was a spontaneous and endothermic process.

  20. Understanding the Photoluminescence Mechanism of Nitrogen-Doped Carbon Dots by Selective Interaction with Copper Ions.

    Science.gov (United States)

    Ganiga, Manjunatha; Cyriac, Jobin

    2016-08-04

    Doped fluorescent carbon dots (CDs) have drawn widespread attention because of their diverse applications and attractive properties. The present report focusses on the origin of photoluminescence in nitrogen-doped CDs (NCDs), which is unraveled by the interaction with Cu(2+) ions. Detailed spectroscopic and microscopic studies reveal that the broad steady-state photoluminescence emission of the NCDs originates from the direct recombination of excitons (high energy) and the involvement of defect states (low energy). In addition, highly selective detection of Cu(2+) is achieved, with a detection limit of 10 μm and a dynamic range of 10 μm-0.4 mm. The feasibility of the present sensor for the detection of Cu(2+) in real water samples is also presented. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Resistance-driven bunching mode of an accelerated ion pulse

    Energy Technology Data Exchange (ETDEWEB)

    Lee, E.P.

    1981-10-16

    Amplification of a longitudinal perturbation of an ion pulse in a linear induction accelerator is calculated. The simplified accelerator model consists only of an applied field (E/sub a/), distributed gap impedance per meter (R) and beam-pipe capacity per meter (C). The beam is treated as a cold, one-dimensional fluid. It is found that normal mode frequencies are nearly real, with only a very small damping rate proportional to R. This result is valid for a general current profile and is not restricted to small R. However, the mode structure exhibits spatial amplification from pulse head to tail by the factor exp(RCLv/sub o//2), where L is pulse length and v/sub 0/ is drift velocity. This factor is very large for typical HIF parameters. An initially small disturbance, when expanded in terms of the normal modes, is found to oscillate with maximum amplitude proportional to the amplification factor.

  2. Copper(II) ions interactions in the systems with triamines and ATP. Potentiometric and spectroscopic studies.

    Science.gov (United States)

    Hoffmann, S K; Goslar, J; Bregier-Jarzebowska, R; Gasowska, A; Zalewska, A; Lomozik, L

    2017-09-09

    The mode of interaction and thermodynamic stability of complexes formed in binary and ternary Cu(II)/ATP/triamines systems were studied using potentiometric and spectroscopic (NMR, EPR, UV-Vis) methods. It was found that in binary metal-free systems ATP/HxPA species are formed (PA: Spd=spermidine or 3,3-tri=1,7-diamino-4-azaheptane) where the phosphate groups from nucleotides are preferred negative centers and protonated amine groups of amines are positive centers of reaction. In the ternary systems Cu/ATP/Hx(PA) as well as Cu/(ATP)(PA) species are formed. The type of the formed Cu(II) complexes depends on pH of the solution. For a low pH value the complexation appears between Cu(II) and ATP molecules via oxygen atoms of phosphate groups. For a very high pH value, where ATP is hydrolyzed, the Cu(II) ions are bound to the nitrogen atoms of polyamine molecules. We did not detect any direct coordination of the N7 nitrogen atom of adenosine to Cu(II) ions. It means that the CuN7 interaction is an indirect type and can be due to noncovalent interplay including water molecule. EPR studies were performed at glassy state (77K) after a fast freezing both for binary and ternary systems. The glassy state EPR spectra do not reflect species identified in titration studies indicating significant effect of rapid temperature decrease on equilibrium of Cu(II) complexes. We propose the molecular structure of all the studied complexes at the glassy state deduced from EPR and optical spectroscopy results. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Biosorption of aluminum, cobalt, and copper ions by Providencia rettgeri isolated from wastewater.

    Science.gov (United States)

    Abo-Amer, Aly E; Ramadan, Abou Bakr; Abo-State, Mervat; Abu-Gharbia, Magdy A; Ahmed, Hamdy E

    2013-06-01

    Twenty-three bacterial isolates from polluted water and soil were screened for heavy metals resistance (i.e., Al(3+), Co(2+), and Cu(2+)). The most potent isolate was identified by morphological characteristics, biochemical tests and confirmed by API20E kits as Providencia rettgeri MAM-4. Removal of Al(3+) from aqueous solution by P. rettgeri is more efficient (∼fourfold) than that by B. cereus ATCC 11778 (a comparison strain) at concentration of 200 mg L(-1) Al(3+). P. rettgeri was able to remove Co(2+) more than B. cereus ATCC 11778 at concentration of 50 mg L(-1) Co(2+). Inoculation of P. rettgeri into clay enhanced significantly the removal of Al(3+), Co(2+), and Cu(2+). P. rettegri MI (mutant strain) was able to tolerate more Al(3+) than that of the parent strain. P. rettgeri was resistant to 7 out of 15 antibiotics tested. P. rettgeri MAM-4 isolated from wastewater had ability to remove Al(3+), Co(2+), and Cu(2+) efficiently from aqueous media; and enhanced significantly metal biosporption by clay. This study has revealed that P. rettgeri could be employed as an effective and economic technology for the removal such metal elements from polluted environment.

  4. Role of graphene layers on the radiation resistance of copper-graphene nanocomposite: Inhibiting the expansion of thermal spike

    Science.gov (United States)

    Huang, Hai; Tang, Xiaobin; Chen, Feida; Liu, Jian; Chen, Da

    2017-09-01

    Metal-graphene nanocomposites are expected to have excellent radiation resistance. The intrinsic role of the graphene layers (GrLs) in their performance has not been fully understood. Five copper-graphene nanocomposite (CGNC) systems were used to investigate the detailed mechanisms underpinning this behaviour by atomistic simulation. Results showed that GrLs can reduce the formation, growth, and intensity of the thermal spike of CGNC; this effect became more evident with the increasing number of layers of graphene. The role of the GrLs can be explained by three mechanisms: first, the ultra-strength C-C bonds of graphene hindered the penetration of high-energy atoms, second, the number of recoiled atoms decreased with the increasing number of layers of graphene, and third, the energy dissipation along the graphene planes also indirectly weakened the damage caused to the entire system. These mechanisms may provide a pathway to prevent material degradation in extreme radiation environments.

  5. Selective dissolution in copper-tin alloys: Formation of corrosion- resistant patina on ancient Chinese bronze mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Taube, M. [State Univ. of New York, Stony Brook, NY (United States). Dept. of Materials Science and Engineering]|[Brookhaven National Lab., Upton, NY (United States); Davenport, A.J. [Brookhaven National Lab., Upton, NY (United States); King, A.H. [State Univ. of New York, Stony Brook, NY (United States). Dept. of Materials Science and Engineering; Chase, T. III [Smithsonian Institution, Washington, D.C. (United States) Freer Gallery of Art, Dept. of Conservation and Scientific Research

    1996-07-01

    Many ancient Chinese bronze mirrors have survived with a patina that leaves the delicate relief surface decorations intact. The microstructure of these ancient mirrors is two-phase and consists of acicular {alpha}-phase (Cu-rich) regions encased in a {delta}-phase (Sn-rich) matrix. At the surface, there is evidence of selective dissolution of the ct phase; the cc-phase regions are replaced pseudomorphically by a mineral product with the {delta} phase remaining metallic. Electrochemical polarization has been used to drive the copper dealloying process in modem, cast bronze. Synchrotron x-ray diffraction was employed to compare the ancient samples with those that were prepared potentiostatically. Poorly crystallized tin oxide (SnO{sub 2}) was found in the {alpha} replacement products of both sample types. The corrosion-resistance of the potentiostatically-treated bronze samples was tested by atmospheric exposure. Comparison with exposed, untreated samples indicated that the treatment was protective.

  6. Inhibition of Staphylococcus aureus biofilm by a copper-bearing 317L-Cu stainless steel and its corrosion resistance.

    Science.gov (United States)

    Sun, Da; Xu, Dake; Yang, Chunguang; Chen, Jia; Shahzad, M Babar; Sun, Ziqing; Zhao, Jinlong; Gu, Tingyue; Yang, Ke; Wang, Guixue

    2016-12-01

    The present study investigated the antibacterial performance, corrosion resistance and surface properties of antibacterial austenitic 317L-Cu stainless steel (317L-Cu SS). After 4.5wt% copper was added to 317L stainless steel (317L SS), the new alloy underwent solid solution and aging heat treatment. Fluorescent staining using 4',6-diamidino-2-phenylindole (DAPI) revealed that the 317L-Cu SS showed strong antibacterial efficacy, achieving a 99% inhibition rate of sessile Staphylococcus aureus cells after 5days. The corrosion data obtained by potentiodynamic polarization curves indicated that in comparison with 317L SS, the pitting potential and corrosion current density of 317L-Cu slightly decreased due to the addition of Cu. The 317L-Cu SS exhibited no cytotoxicity against zebrafish (Danio rerio) embryos. The experimental results in this study demonstrated that the new alloy has potential applications in medical and daily uses.

  7. Heat-Affected Zone Liquation Cracking Resistance of Friction Stir Processed Aluminum-Copper Alloy AA 2219

    Science.gov (United States)

    Karthik, G. M.; Janaki Ram, G. D.; Kottada, Ravi Sankar

    2016-12-01

    In the current work, the effect of friction stir processing on heat-affected zone (HAZ) liquation cracking resistance of aluminum-copper alloy AA 2219 was evaluated. In Gleeble hot-ductility tests and longitudinal Varestraint tests, the FSPed material, despite its very fine dynamically recrystallized equiaxed grain structure, showed considerably higher susceptibility to HAZ liquation cracking when compared to the base material. Detailed microstructural studies showed that the increased cracking susceptibility of the FSPed material is due to (i) increase in the amount of liquating θ phase (equilibrium Al2Cu) and (ii) increase in the population of grain boundary θ particles. An important learning from the current work is that, in certain materials like alloy 2219, the use of FSP as a pretreatment to fusion welding can be counterproductive.

  8. Heat-Affected Zone Liquation Cracking Resistance of Friction Stir Processed Aluminum-Copper Alloy AA 2219

    Science.gov (United States)

    Karthik, G. M.; Janaki Ram, G. D.; Kottada, Ravi Sankar

    2017-04-01

    In the current work, the effect of friction stir processing on heat-affected zone (HAZ) liquation cracking resistance of aluminum-copper alloy AA 2219 was evaluated. In Gleeble hot-ductility tests and longitudinal Varestraint tests, the FSPed material, despite its very fine dynamically recrystallized equiaxed grain structure, showed considerably higher susceptibility to HAZ liquation cracking when compared to the base material. Detailed microstructural studies showed that the increased cracking susceptibility of the FSPed material is due to (i) increase in the amount of liquating θ phase (equilibrium Al2Cu) and (ii) increase in the population of grain boundary θ particles. An important learning from the current work is that, in certain materials like alloy 2219, the use of FSP as a pretreatment to fusion welding can be counterproductive.

  9. Trophic-metabolic activity of earthworms (Lumbricidae as a zoogenic factor of maintaining reclaimed soils’ resistance to copper contamination

    Directory of Open Access Journals (Sweden)

    Y. L. Kulbachko

    2014-07-01

    which restricts movement of excess chemicals, maintains stability and increases resistance to soil contamination, in particular, with copper. Besides, it is possible to accelerate the artificial forest edaphotop naturalization on reclaimed land, and to increase its ecological value

  10. Durable Corrosion Resistance of Copper Due to Multi-Layer Graphene

    Directory of Open Access Journals (Sweden)

    Abhishek Tiwari

    2017-09-01

    Full Text Available Ultra-thin graphene coating has been reported to provide considerable resistance against corrosion during short-term exposures, however, there is great variability in the corrosion resistance due to graphene coating in different studies. It may be possible to overcome the problem of hampered corrosion protection ability of graphene that is caused due to defective single layer graphene by applying multilayer graphene. Systematic electrochemical characterization showed that the multilayer graphene coating developed in the study provided significant corrosion resistance in a chloride solution and the corrosion resistance was sustained for long durations (~400 h, which is attributed to the multilayer graphene.

  11. ADSORPTION OF ION EXCHANGE RESIN FOR COPPER ION IN ORGANIC WASTE WATER%离子交换树脂对有机废水中铜离子的吸附

    Institute of Scientific and Technical Information of China (English)

    张剑波; 王维敬; 祝乐

    2001-01-01

    Different ion exchange resins were selected to adsorb the copperion in organic wastewater. The absorption rate of resin for copper was determined. The impact of copper ion concentration and pH value on absorption rate, and the regenesis capability of the resin were tested. Results showed "zhengguang", "Qiangsuan 1#" and PK208 resin possess outstanding performance, which should be used in decontamination of wastewater that contains copper ion.%选用多种大孔强酸型离子交换树脂,用于吸附浓集含有机物废水中的铜离子,通过测定各种树脂对铜离子的去除率、不同铜离子浓度和溶液pH值对去除率的影响,以及各树脂再生性能的比较,表明“争光”、“强酸1号”和PK208树脂性能最为突出,效果明显优于其它几种树脂,可用于吸附处理有机废水中的铜离子。

  12. Investigation of low-resistivity from hydrogenated lightly B-doped diamond by ion implantation

    Directory of Open Access Journals (Sweden)

    Cui Xia Yan et al

    2008-01-01

    Full Text Available We have implanted boron (B ions (dosage: 5×1014 cm-2 into diamond and then hydrogenated the sample by implantating hydrogen ions at room temperature. A p-type diamond material with a low resistivity of 7.37 mΩ cm has been obtained in our experiment, which suggests that the hydrogenation of B-doped diamond results in a low-resistivity p-type material. Interestingly, inverse annealing, in which carrier concentration decreased with increasing annealing temperature, was observed at annealing temperatures above 600 °C. In addition, the formation mechanism of a low-resistivity material has been studied by density functional theory calculation using a plane wave method.

  13. Bivalent Copper Ions Promote Fibrillar Aggregation of KCTD1 and Induce Cytotoxicity.

    Science.gov (United States)

    Liu, Zhepeng; Song, Feifei; Ma, Zhi-Li; Xiong, Qiushuang; Wang, Jingwen; Guo, Deyin; Sun, Guihong

    2016-01-01

    Potassium channel tetramerization domain containing 1 (KCTD1) family members have a BTB/POZ domain, which can facilitate protein-protein interactions involved in the regulation of different signaling pathways. KCTD proteins have potential Zn(2+)/Cu(2+) binding sites with currently unknown structural and functional roles. We investigated potential Cu(2+)-specific effects on KCTD1 using circular dichroism, turbidity measurement, fluorescent dye binding, proteinase K (PK) digestion, cell proliferation and apoptosis assays. These experiments indicate that the KCTD1 secondary structure assumes greater β-sheet content and the proteins aggregate into a PK-resistant form under 20 μM Cu(2+), and this β-sheet-rich aggregation with Cu(2+) promotes fibril formation, which results in increased cell toxicity by apoptosis. Our results reveal a novel role for Cu(2+) in determining the structure and function of KCTD1.

  14. Removal of copper, nickel and zinc ions from aqueous solution by chitosan-8-hydroxyquinoline beads

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Francisco C.F.; Dias, Francisco S.; Vasconcellos, Luiz C.G. [Departamento de Quimica Organica e Inorganica, Campus do Pici - Universidade Federal do Ceara, Fortaleza (Brazil); Sousa, Francisco W. [Departamento de Engenharia Hidraulica e Ambiental, Campus do Pici - Universidade Federal do Ceara, Fortaleza (Brazil); Cavalcante, Rivelino M.; Carvalho, Tecia V.; Queiroz, Danilo C. [Departamento de Quimica Analitica e Fisico Quimica, Campus do Pici - Universidade Federal do Ceara, Fortaleza (Brazil); Nascimento, Ronaldo F.

    2008-03-15

    In this work, 8-hydroxyquinoline is used as the active sites in cross-linked chitosan beads with epichlorohydrin (CT-8HQ). The CT-8HQ material was shaped in bead form and used for heavy metal removal from aqueous solution. The study was carried out at pH 5.0 with both batch and column methods and the maximum adsorption capacity of metal ions by the CT-8HQ was attained in 4 h in the batch experiment. The adsorption capacity order was: Cu{sup 2+} > Ni{sup 2+} > Zn{sup 2+} for both mono- and multi-component systems with batch conditions. From breakthrough curves with column conditions, the adsorption capacity followed the order Cu{sup 2+} > Zn{sup 2+} > Ni{sup 2+} for both mono- and multi-component systems. The CT-8HQ beads maintained good metal adsorption capacity for all five cycles with absorbent restoration achieved with the use of 1.0 mol L{sup -1} HCl solution, with 90% regeneration. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  15. Increased Uptake of Chelated Copper Ions by Lolium perenne Attributed to Amplified Membrane and Endodermal Damage

    Directory of Open Access Journals (Sweden)

    Anthea Johnson

    2015-10-01

    Full Text Available The contributions of mechanisms by which chelators influence metal translocation to plant shoot tissues are analyzed using a combination of numerical modelling and physical experiments. The model distinguishes between apoplastic and symplastic pathways of water and solute movement. It also includes the barrier effects of the endodermis and plasma membrane. Simulations are used to assess transport pathways for free and chelated metals, identifying mechanisms involved in chelate-enhanced phytoextraction. Hypothesized transport mechanisms and parameters specific to amendment treatments are estimated, with simulated results compared to experimental data. Parameter values for each amendment treatment are estimated based on literature and experimental values, and used for model calibration and simulation of amendment influences on solute transport pathways and mechanisms. Modeling indicates that chelation alters the pathways for Cu transport. For free ions, Cu transport to leaf tissue can be described using purely apoplastic or transcellular pathways. For strong chelators (ethylenediaminetetraacetic acid (EDTA and diethylenetriaminepentaacetic acid (DTPA, transport by the purely apoplastic pathway is insufficient to represent measured Cu transport to leaf tissue. Consistent with experimental observations, increased membrane permeability is required for simulating translocation in EDTA and DTPA treatments. Increasing the membrane permeability is key to enhancing phytoextraction efficiency.

  16. Increased Uptake of Chelated Copper Ions by Lolium perenne Attributed to Amplified Membrane and Endodermal Damage.

    Science.gov (United States)

    Johnson, Anthea; Singhal, Naresh

    2015-10-23

    The contributions of mechanisms by which chelators influence metal translocation to plant shoot tissues are analyzed using a combination of numerical modelling and physical experiments. The model distinguishes between apoplastic and symplastic pathways of water and solute movement. It also includes the barrier effects of the endodermis and plasma membrane. Simulations are used to assess transport pathways for free and chelated metals, identifying mechanisms involved in chelate-enhanced phytoextraction. Hypothesized transport mechanisms and parameters specific to amendment treatments are estimated, with simulated results compared to experimental data. Parameter values for each amendment treatment are estimated based on literature and experimental values, and used for model calibration and simulation of amendment influences on solute transport pathways and mechanisms. Modeling indicates that chelation alters the pathways for Cu transport. For free ions, Cu transport to leaf tissue can be described using purely apoplastic or transcellular pathways. For strong chelators (ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA)), transport by the purely apoplastic pathway is insufficient to represent measured Cu transport to leaf tissue. Consistent with experimental observations, increased membrane permeability is required for simulating translocation in EDTA and DTPA treatments. Increasing the membrane permeability is key to enhancing phytoextraction efficiency.

  17. Influence of the Ion Coordination Number on Cation Exchange Reactions with Copper Telluride Nanocrystals

    CERN Document Server

    Tu, Renyong; Bertoni, Giovanni; Lak, Aidin; Gaspari, Roberto; Rapallo, Arnaldo; Cavalli, Andrea; De Trizio, Luca; Manna, Liberato

    2016-01-01

    Cu2-xTe nanocubes were used as starting seeds to access metal telluride nanocrystals by cation exchanges at room temperature. The coordination number of the entering cations was found to play an important role in dictating the reaction pathways. The exchanges with tetrahedrally coordinated cations (i.e. with coordination number 4), such as Cd2+ or Hg2+, yielded monocrystalline CdTe or HgTe nanocrystals with Cu2-xTe/CdTe or Cu2-xTe/HgTe Janus-like heterostructures as intermediates. The formation of Janus-like architectures was attributed to the high diffusion rate of the relatively small tetrahedrally coordinated cations, which could rapidly diffuse in the Cu2-xTe NCs and nucleate the CdTe (or HgTe) phase in a preferred region of the host structure. Also, with both Cd2+ and Hg2+ ions the exchange led to wurtzite CdTe and HgTe phases rather than the more stable zinc-blende ones, indicating that the anion framework of the starting Cu2- xTe particles could be more easily deformed to match the anion framework of t...

  18. Simple PEG modification of DNA aptamer based on copper ion coordination for tumor targeting.

    Science.gov (United States)

    Takafuji, Yoshimasa; Jo, Jun-ichiro; Tabata, Yasuhiko

    2011-01-01

    A simple modification of a DNA aptamer with poly(ethylene glycol) (PEG) based on metal coordination was developed. N,N-bis(carboxymethyl)-L-lysine (NTA) of a metal chelate residue was chemically introduced to one terminus of PEG. The NTA-introduced PEG (PEG-NTA) chelated Cu(2+) ions form a Cu(2+)-chelated PEG (PEG-Cu). When PEG-Cu was mixed with a DNA aptamer of anti-tumor activity (AS1411) in aqueous solution, a complex of PEG-Cu and AS1411 based on metal coordination was formed. The complex inhibited in vitro tumor growth in a dose-dependent manner. A body distribution study with tumor-bearing mice revealed that PEG-Cu-AS1411 complexes injected intravenously had a significant longer lifetime in the blood circulation and 1.5-2.0-fold higher accumulation in the tumor tissue than free AS1411. Intravenous injection of complexes suppressed the in vivo growth of tumor mass to a significantly greater extent compared with that of free AS1411. The Cu(2+)-coordinated PEG modification is a simple and promising method to enhance accumulation of the aptamer in the tumor, resulting in the augmented anti-tumor effect.

  19. A New Rhodamine B Derivative As a Colorimetric Chemosensor for Recognition of Copper(II) Ion

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Lijun; Li, Fangfang; Liu, Minghui [Bohai University, Jinzhou (China); Nandhakumar, Raju [Karunya University, TamilNadu (India)

    2010-11-15

    A new rhodamine-based sensor 1 was designed and synthesized by incorporating rhodamine B and benzimidazole moieties. Sensor 1 exhibits high selectivity and sensitivity to Cu{sup 2+} in CH{sub 3}CN-water solution (HEPES buffer, pH = 7.0) with an obvious color change from colorless to pink. Other metal ions such as Hg{sup 2+}, Ag{sup +}, Pb{sup 2+}, Sr{sup 2+}, Ba{sup 2+}, Cd{sup 2+}, Ni{sup 2+}, Co{sup 2+}, Fe{sup 2+}, Mn{sup 2+}, Cu{sup 2+}, Zn{sup 2+}, Ce{sup 3+}, Mg{sup 2+}, K{sup +} and Na{sup +} had no such color change and have no significant influence on Cu{sup 2+} recognition process. The interaction of Cu{sup 2+} and sensor 1 was proven to adopt a 1:1 binding stoichiometry and the recognition process is reversible.

  20. Copper Ion Attenuated the Antiproliferative Activity of Di-2-pyridylhydrazone Dithiocarbamate Derivative; However, There Was a Lack of Correlation between ROS Generation and Antiproliferative Activity.

    Science.gov (United States)

    Wang, Tingting; Fu, Yun; Huang, Tengfei; Liu, Youxun; Wu, Meihao; Yuan, Yanbin; Li, Shaoshan; Li, Changzheng

    2016-08-20

    The use of chelators for cancer treatment has been an alternative option. Dithiocarbamates have recently attracted considerable attention owning to their diverse biological activities; thus, the preparation of new dithiocarbamate derivatives with improved antitumor activity and selectivity as well as probing the underlying molecular mechanism are required. In this study, di-2-pyridylhydrazone dithiocarbamate S-propionic acid (DpdtpA) and its copper complex were prepared and characterized, and its antiproliferative activity was evaluated. The proliferation inhibition assay showed that DpdtpA exhibited excellent antiproliferative effect in hepatocellular carcinoma (IC50 = 1.3 ± 0.3 μM for HepG2, and 2.5 ± 0.6 μM for Bel-7402). However, in the presence of copper ion, the antiproliferative activity of DpdtpA was dramatically attenuated (20-30 fold) owing to the formation of copper chelate. A preliminarily mechanistic study revealed that reactive oxygen species (ROS) generation mediated the antiproliferative activity of DpdtpA, and accordingly induced apoptosis, DNA cleavage, and autophagy. Surprisingly, the cytotoxicity of DpdtpA copper complex (DpdtpA-Cu) was also involved in ROS generation; however, a paradoxical relation between cellular ROS level and cytotoxicity was observed. Further investigation indicated that DpdtpA could induce cell cycle arrest at the S phase; however, DpdtpA-Cu lacked this effect, which explained the difference in their antiproliferative activity.

  1. Copper Ion Attenuated the Antiproliferative Activity of Di-2-pyridylhydrazone Dithiocarbamate Derivative; However, There Was a Lack of Correlation between ROS Generation and Antiproliferative Activity

    Directory of Open Access Journals (Sweden)

    Tingting Wang

    2016-08-01

    Full Text Available The use of chelators for cancer treatment has been an alternative option. Dithiocarbamates have recently attracted considerable attention owning to their diverse biological activities; thus, the preparation of new dithiocarbamate derivatives with improved antitumor activity and selectivity as well as probing the underlying molecular mechanism are required. In this study, di-2-pyridylhydrazone dithiocarbamate S-propionic acid (DpdtpA and its copper complex were prepared and characterized, and its antiproliferative activity was evaluated. The proliferation inhibition assay showed that DpdtpA exhibited excellent antiproliferative effect in hepatocellular carcinoma (IC50 = 1.3 ± 0.3 μM for HepG2, and 2.5 ± 0.6 μM for Bel-7402. However, in the presence of copper ion, the antiproliferative activity of DpdtpA was dramatically attenuated (20–30 fold owing to the formation of copper chelate. A preliminarily mechanistic study revealed that reactive oxygen species (ROS generation mediated the antiproliferative activity of DpdtpA, and accordingly induced apoptosis, DNA cleavage, and autophagy. Surprisingly, the cytotoxicity of DpdtpA copper complex (DpdtpA–Cu was also involved in ROS generation; however, a paradoxical relation between cellular ROS level and cytotoxicity was observed. Further investigation indicated that DpdtpA could induce cell cycle arrest at the S phase; however, DpdtpA–Cu lacked this effect, which explained the difference in their antiproliferative activity.

  2. Erratum to: Study on Chloride Ion Penetration Resistance of Rubberized Concrete Under Steady State Condition

    Directory of Open Access Journals (Sweden)

    Md Noor Nurazuwa

    2016-01-01

    In this paper, the effect of crumb rubber, CR as fine aggregate in the concrete to enhance concrete durability against chloride ion diffusion was studied. Chloride ion diffusion in rubberized concrete was tested by migration test under steady state condition. Concrete specimen with water-to-cement ratio of 0.50 was prepared to study the CR effectiveness in comparison with lower water-to-cement ratio. In addition, 10% silica fume, SF was added to provide denser concrete and to understand its effectiveness against chloride ion diffusion. Results showed that chloride transport characteristics were improved by the increasing amount of CR in all mixed due to the fact that CR has the ability to repel water. Meanwhile, rubberized concrete with w/c = 0.35 gave better resistance against chloride ion penetration compared to w/c = 0.50. This was much improved with combination of CR and SF.

  3. Development of two highly sensitive immunoassays for detection of copper ions and a suite of relevant immunochemicals

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Hongwei [College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193 (China); Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, Honolulu, HI 96822 (United States); Nan Tiegui; Tan Guiyu; Gao Wei; Cao Zhen; Sun Shuo; Li Zhaohu [College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193 (China); Li, Qing X., E-mail: qingl@hawaii.edu [Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, Honolulu, HI 96822 (United States); Wang Baomin, E-mail: wbaomin@263.com [College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193 (China)

    2011-09-19

    Highlights: {center_dot} Two highly sensitive immunoassays for determination of Cu(II) at sub ppb levels. {center_dot} The heterologous competitive enzyme linked immunosorbent assay for heavy metals. {center_dot} Haptenated protein directly conjugated with HRP can reduce the loss of HRP activity. - Abstract: Availability of highly sensitive assays for metal ions can help monitor and manage the environmental and food contamination. In the present study, a monoclonal antibody against Copper(II)-ethylenediaminetetraacetic acid was used to develop two sensitive ELISAs for Cu(II) analysis. Cobalt(II)-EDTA-BSA was the coating antigen in a heterologous indirect competitive ELISA (hicELISA), whereas Co(II)-EDTA-BSA-horseradish peroxidase (HRP) was the enzyme tracer in a heterologous direct competitive ELISA (hdcELISA). Both ELISAs were validated for detecting the content of Cu(II) in environmental waters. The ELISA data agreed well with those from graphite furnace atomic absorption spectroscopy. The methods of developing the Cu(II) hicELISA and hdcELISA are potentially applicable for developing ELISAs for other metals. The chelator-protein complexes such as EDTA-BSA and EDTA-BSA-HRP can form a suite of metal complexes having the consistent hapten density, location and orientation on the conjugates except the difference of the metal core, which can be used as ideal reagents to investigate the relationship between assay sensitivity and antibody affinities for the haptens and the analytes. The strategy of conjugating a haptenated protein directly with HRP can reduce the loss of HRP activity during the conjugation reaction and thus can be applicable for the development of ELISAs for small molecules.

  4. New force field parameters for metalloproteins I: Divalent copper ion centers including three histidine residues and an oxygen-ligated amino acid residue.

    Science.gov (United States)

    Wise, Olivia; Coskuner, Orkid

    2014-06-30

    Transition metal ion complexation with proteins is ubiquitous across such diverse fields as neurodegenerative and cardiovascular diseases and cancer. In this study, the structures of divalent copper ion centers including three histidine and one oxygen-ligated amino acid residues and the relative binding affinities of the oxygen-ligated amino acid residues with these metal ion centers, which are debated in the literature, are presented. Furthermore, new force field parameters, which are currently lacking for the full-length metal-ligand moieties, are developed for metalloproteins that have these centers. These new force field parameters enable investigations of metalloproteins possessing these binding sites using molecular simulations. In addition, the impact of using the atom equivalence and inequivalence atomic partial charge calculation procedures on the simulated structures of these metallopeptides, including hydration properties, is described.

  5. Effect of calcium and phosphorus ion implantation on the corrosion resistance and biocompatibility of titanium.

    Science.gov (United States)

    Krupa, D; Baszkiewicz, J; Kozubowski, J A; Lewandowska-Szumieł, M; Barcz, A; Sobczak, J W; Biliński, A; Rajchel, A

    2004-01-01

    This paper is concerned with the corrosion resistance and biocompatibility of titanium after surface modification by the ion implantation of calcium or phosphorus or calcium + phosphorus. Calcium and phosphorus ions were implanted in a dose of 10(17) ions/cm(2). The ion beam energy was 25 keV. The microstructure of the implanted layers was examined by TEM. The chemical composition of the surface layers was determined by XPS and SIMS. The corrosion resistance was examined by electrochemical methods in a simulated body fluid (SBF) at a temperature of 37 degrees C. The biocompatibility was evaluated in vitro. As shown by TEM results, the surface layers formed during calcium, phosphorus and calcium + phosphorus implantation were amorphous. The results of the electrochemical examinations (Stern's method) indicate that the calcium, phosphorus and calcium + phosphorus implantation into the surface of titanium increases its corrosion resistance in stationary conditions after short- and long-term exposures in SBF. Potentiodynamic tests show that the calcium-implanted samples undergo pitting corrosion during anodic polarisation. The breakdown potentials measured are high (2.5 to 3 V). The good biocompatibility of all the investigated materials was confirmed under the specific conditions of the applied examination, although, in the case of calcium implanted titanium it was not as good as that of non-implanted titanium.

  6. Streptococcus mutans copper chaperone, CopZ, is critical for biofilm formation and competitiveness.

    Science.gov (United States)

    Garcia, S S; Du, Q; Wu, H

    2016-12-01

    The oral cavity is a dynamic environment characterized by hundreds of bacterial species, saliva, and an influx of nutrients and metal ions such as copper. Although there is a physiologic level of copper in the saliva, the oral cavity is often challenged with an influx of copper ions. At high concentrations copper is toxic and must therefore be strictly regulated by pathogens for them to persist and cause disease. The cariogenic pathogen Streptococcus mutans manages excess copper using the copYAZ operon that encodes a negative DNA-binding repressor (CopY), the P1-ATPase copper exporter (CopA), and the copper chaperone (CopZ). These hypothetical roles of the copYAZ operon in regulation and copper transport to receptors led us to investigate their contribution to S. mutans virulence. Mutants defective in the copper chaperone CopZ, but not CopY or CopA, were impaired in biofilm formation and competitiveness against commensal streptococci. Characterization of the CopZ mutant biofilm revealed a decreased secretion of glucosyltransferases and reduced expression of mutacin genes. These data suggest that the function of copZ on biofilm and competitiveness is independent of copper resistance and CopZ is a global regulator for biofilm and other virulence factors. Further characterization of CopZ may lead to the identification of new biofilm pathways. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Ultrahigh Oxidation Resistance and High Electrical Conductivity in Copper-Silver Powder

    Science.gov (United States)

    Li, Jiaxiang; Li, Yunping; Wang, Zhongchang; Bian, Huakang; Hou, Yuhang; Wang, Fenglin; Xu, Guofu; Liu, Bin; Liu, Yong

    2016-12-01

    The electrical conductivity of pure Cu powder is typically deteriorated at elevated temperatures due to the oxidation by forming non-conducting oxides on surface, while enhancing oxidation resistance via alloying is often accompanied by a drastic decline of electrical conductivity. Obtaining Cu powder with both a high electrical conductivity and a high oxidation resistance represents one of the key challenges in developing next-generation electrical transferring powder. Here, we fabricate a Cu-Ag powder with a continuous Ag network along grain boundaries of Cu particles and demonstrate that this new structure can inhibit the preferential oxidation in grain boundaries at elevated temperatures. As a result, the Cu-Ag powder displays considerably high electrical conductivity and high oxidation resistance up to approximately 300 °C, which are markedly higher than that of pure Cu powder. This study paves a new pathway for developing novel Cu powders with much enhanced electrical conductivity and oxidation resistance in service.

  8. Evaluation of Cracking Resistance of Copper-Bearing Age Hardening Steel Weldment

    Institute of Scientific and Technical Information of China (English)

    CHAI Feng; YANG Cai-fu; SU Hang; ZHANG Yong-quan; XU Zhou

    2007-01-01

    The weldability of a low-carbon copper-bearing age hardening steel was evaluated using cracking susceptibility calculation, HAZ maximum hardness measurement, and Y-groove cracking evaluation test. The results show that the hardenability characteristics and cold cracking susceptibility of the steel are very low. The results also indicate that a crack-free weldment can be obtained during the welding of this type of steel even at an ambient temperature as low as -5 ℃ as well as in an absolute humidity lower than 4 000 Pa without any preheat treatment. A slight preheat treatment can prevent the joint from cracking when welding is carried out at lower ambient temperature or higher absolute humidity.

  9. Facile fabrication of superhydrophobic surface with excellent mechanical abrasion and corrosion resistance on copper substrate by a novel method.

    Science.gov (United States)

    Su, Fenghua; Yao, Kai

    2014-06-11

    A novel method for controllable fabrication of a superhydrophobic surface with a water contact angle of 162 ± 1° and a sliding angle of 3 ± 0.5° on copper substrate is reported in this Research Article. The facile and low-cost fabrication process is composed from the electrodeposition in traditional Watts bath and the heat-treatment in the presence of (heptadecafluoro-1,1,2,2-tetradecyl) triethoxysilane (AC-FAS). The superhydrophobicity of the fabricated surface results from its pine-cone-like hierarchical micro-nanostructure and the assembly of low-surface-energy fluorinated components on it. The superhydrophobic surface exhibits high microhardness and excellent mechanical abrasion resistance because it maintains superhydrophobicity after mechanical abrasion against 800 grit SiC sandpaper for 1.0 m at the applied pressure of 4.80 kPa. Moreover, the superhydrophobic surface has good chemical stability in both acidic and alkaline environments. The potentiodynamic polarization and electrochemical impedance spectroscopy test shows that the as-prepared superhydrophobic surface has excellent corrosion resistance that can provide effective protection for the bare Cu substrate. In addition, the as-prepared superhydrophobic surface has self-cleaning ability. It is believed that the facile and low-cost method offer an effective strategy and promising industrial applications for fabricating superhydrophobic surfaces on various metallic materials.

  10. A novel solidified floating organic drop microextraction method for preconcentration and determination of copper ions by flow injection flame atomic absorption spectrometry.

    Science.gov (United States)

    Sahin, Ciğdem Arpa; Tokgöz, Ilknur

    2010-05-14

    A rapid, simple and cost effective solidified floating organic drop microextraction (SFODME) and flow injection flame atomic absorption spectrometric determination (FI-FAAS) method for copper was developed. In this method, a free microdrop of 1-undecanol containing 1,5-diphenyl carbazide (DPC) as the complexing agent was transferred to the surface of an aqueous sample including Cu(II) ions, while being agitated by a stirring bar in the bulk of the solution. Under the proper stirring conditions, the suspended microdrop can remain at the top-center position of the aqueous sample. After the completion of the extraction, the sample vial was cooled by placing it in a refrigerator for 10min. The solidified microdrop was then transferred into a conical vial, where it melted immediately and diluted to 300microL with ethanol. Finally, copper ions in 200microL of diluted solution were determined by FI-FAAS. Several factors affecting the microextraction efficiency, such as type of extraction solvent, pH, complexing agent concentration, extraction time, stirring rate, sample volume and temperature were investigated and optimized. Under optimized conditions for 100mL of solution, the preconcentration factor was 333 and the enrichment factor was 324. The limit of detection (3s) was 0.4ngmL(-1), the limit of quantification (10s) was 1.1ngmL(-1) and the relative standard deviation (RSD) for 10 replicate measurements of 10ngmL(-1) copper was 0.9%. The proposed method was successfully applied to the determination of copper in different water samples.

  11. Fabricating Copper Nanotubes by Electrodeposition

    Science.gov (United States)

    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.

  12. Lack of Involvement of Fenton Chemistry in Death of Methicillin-Resistant and Methicillin-Sensitive Strains of Staphylococcus aureus and Destruction of Their Genomes on Wet or Dry Copper Alloy Surfaces.

    Science.gov (United States)

    Warnes, Sarah L; Keevil, C William

    2016-01-29

    The pandemic of hospital-acquired infections caused by methicillin-resistant Staphylococcus aureus (MRSA) has declined, but the evolution of strains with enhanced virulence and toxins and the increase of community-associated infections are still a threat. In previous studies, 10(7) MRSA bacteria applied as simulated droplet contamination were killed on copper and brass surfaces within 90 min. However, contamination of surfaces is often via finger tips and dries rapidly, and it may be overlooked by cleaning regimes (unlike visible droplets). In this new study, a 5-log reduction of a hardy epidemic strain of MRSA (epidemic methicillin-resistant S. aureus 16 [EMRSA-16]) was observed following 10 min of contact with copper, and a 4-log reduction was observed on copper nickel and cartridge brass alloys in 15 min. A methicillin-sensitive S. aureus (MSSA) strain from an osteomyelitis patient was killed on copper surfaces in 15 min, and 4-log and 3-log reductions occurred within 20 min of contact with copper nickel and cartridge brass, respectively. Bacterial respiration was compromised on copper surfaces, and superoxide was generated as part of the killing mechanism. In addition, destruction of genomic DNA occurs on copper and brass surfaces, allaying concerns about horizontal gene transfer and copper resistance. Incorporation of copper alloy biocidal surfaces may help to reduce the spread of this dangerous pathogen. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  13. Lack of Involvement of Fenton Chemistry in Death of Methicillin-Resistant and Methicillin-Sensitive Strains of Staphylococcus aureus and Destruction of Their Genomes on Wet or Dry Copper Alloy Surfaces

    Science.gov (United States)

    2016-01-01

    The pandemic of hospital-acquired infections caused by methicillin-resistant Staphylococcus aureus (MRSA) has declined, but the evolution of strains with enhanced virulence and toxins and the increase of community-associated infections are still a threat. In previous studies, 107 MRSA bacteria applied as simulated droplet contamination were killed on copper and brass surfaces within 90 min. However, contamination of surfaces is often via finger tips and dries rapidly, and it may be overlooked by cleaning regimes (unlike visible droplets). In this new study, a 5-log reduction of a hardy epidemic strain of MRSA (epidemic methicillin-resistant S. aureus 16 [EMRSA-16]) was observed following 10 min of contact with copper, and a 4-log reduction was observed on copper nickel and cartridge brass alloys in 15 min. A methicillin-sensitive S. aureus (MSSA) strain from an osteomyelitis patient was killed on copper surfaces in 15 min, and 4-log and 3-log reductions occurred within 20 min of contact with copper nickel and cartridge brass, respectively. Bacterial respiration was compromised on copper surfaces, and superoxide was generated as part of the killing mechanism. In addition, destruction of genomic DNA occurs on copper and brass surfaces, allaying concerns about horizontal gene transfer and copper resistance. Incorporation of copper alloy biocidal surfaces may help to reduce the spread of this dangerous pathogen. PMID:26826226

  14. Contact resistance and normal zone formation in coated yttrium barium copper oxide superconductors

    Science.gov (United States)

    Duckworth, Robert Calvin

    2001-11-01

    This project presents a systematic study of contact resistance and normal zone formation in silver coated YBa2CU3Ox (YBCO) superconductors. A unique opportunity exists in YBCO superconductors because of the ability to use oxygen annealing to influence the interfacial properties and the planar geometry of this type of superconductor to characterize the contact resistance between the silver and YBCO. The interface represents a region that current must cross when normal zones form in the superconductor and a high contact resistance could impede the current transfer or produce excess Joule heating that would result in premature quench or damage of the sample. While it has been shown in single-crystalline YBCO processing methods that the contact resistance of the silver/YBCO interface can be influenced by post-process oxygen annealing, this has not previously been confirmed for high-density films, nor for samples with complete layers of silver deposited on top of the YBCO. Both the influence of contact resistance and the knowledge of normal zone formation on conductor sized samples is essential for their successful implementation into superconducting applications such as transmission lines and magnets. While normal zone formation and propagation have been studied in other high temperature superconductors, the amount of information with respect to YBCO has been very limited. This study establishes that the processing method for the YBCO does not affect the contact resistance and mirrors the dependence of contact resistance on oxygen annealing temperature observed in earlier work. It has also been experimentally confirmed that the current transfer length provides an effective representation of the contact resistance when compared to more direct measurements using the traditional four-wire method. Finally for samples with low contact resistance, a combination of experiments and modeling demonstrate an accurate understanding of the key role of silver thickness and substrate

  15. Comparison of Several Methods for Determining the Internal Resistance of Lithium Ion Cells

    Directory of Open Access Journals (Sweden)

    Hans-Georg Schweiger

    2010-06-01

    Full Text Available The internal resistance is the key parameter for determining power, energy efficiency and lost heat of a lithium ion cell. Precise knowledge of this value is vital for designing battery systems for automotive applications. Internal resistance of a cell was determined by current step methods, AC (alternating current methods, electrochemical impedance spectroscopy and thermal loss methods. The outcomes of these measurements have been compared with each other. If charge or discharge of the cell is limited, current step methods provide the same results as energy loss methods.

  16. Comparison of Several Methods for Determining the Internal Resistance of Lithium Ion Cells

    Science.gov (United States)

    Schweiger, Hans-Georg; Obeidi, Ossama; Komesker, Oliver; Raschke, André; Schiemann, Michael; Zehner, Christian; Gehnen, Markus; Keller, Michael; Birke, Peter

    2010-01-01

    The internal resistance is the key parameter for determining power, energy efficiency and lost heat of a lithium ion cell. Precise knowledge of this value is vital for designing battery systems for automotive applications. Internal resistance of a cell was determined by current step methods, AC (alternating current) methods, electrochemical impedance spectroscopy and thermal loss methods. The outcomes of these measurements have been compared with each other. If charge or discharge of the cell is limited, current step methods provide the same results as energy loss methods. PMID:22219678

  17. Selective extraction and release using (EDTA-Ni)-layered double hydroxide coupled with catalytic oxidation of 3,3',5,5'-tetramethylbenzidine for sensitive detection of copper ion.

    Science.gov (United States)

    Tang, Sheng; Chang, Yuepeng; Chia, Guo Hui; Lee, Hian Kee

    2015-07-23

    Copper is an important heavy metal in various biological processes. Many methods have been developed for detecting of copper ions (Cu(2+)) in aqueous samples. However, an easy, cheap, selective and sensitive method is still desired. In this study, a selective extraction-release-catalysis approach has been developed for sensitive detection of copper ion. Ethylenediaminetetraacetic acid (EDTA) chelated with nickel ion (Ni(2+)) were intercalated in a layered double hydroxide via a co-precipitation reaction. The product was subsequently applied as sorbent in dispersive solid-phase extraction for the enrichment of Cu(2+) at pH 6. Since Cu(2+) has a stronger complex formation constant with EDTA, Ni(2+) exchanged with Cu(2+) selectively. The resulting sorbent containing Cu(2+) was transferred to catalyze the 3,3',5,5'-tetramethylbenzidine oxidation reaction, since Cu(2+) could be released by the sorbent effectively and has high catalytic ability for the reaction. Blue light emitted from the oxidation product was measured by ultraviolet-visible spectrophotometry for the determination of Cu(2+). The extraction temperature, extraction time, and catalysis time were optimized. The results showed that this method provided a low limit of detection of 10nM, a wide linear range (0.05-100μM) and good linearity (r(2)=0.9977). The optimized conditions were applied to environmental water samples. Using Cu(2+) as an example, this work provided a new and interesting approach for the convenient and efficient detection of metal cations in aqueous samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Integrated miniature fluorescent probe to leverage the sensing potential of ZnO quantum dots for the detection of copper (II) ions.

    Science.gov (United States)

    Ng, Sing Muk; Wong, Derrick Sing Nguong; Phung, Jane Hui Chiun; Chin, Suk Fun; Chua, Hong Siang

    2013-11-15

    Quantum dots are fluorescent semiconductor nanoparticles that can be utilised for sensing applications. This paper evaluates the ability to leverage their analytical potential using an integrated fluorescent sensing probe that is portable, cost effective and simple to handle. ZnO quantum dots were prepared using the simple sol-gel hydrolysis method at ambient conditions and found to be significantly and specifically quenched by copper (II) ions. This ZnO quantum dots system has been incorporated into an in-house developed miniature fluorescent probe for the detection of copper (II) ions in aqueous medium. The probe was developed using a low power handheld black light as excitation source and three photo-detectors as sensor. The sensing chamber placed between the light source and detectors was made of 4-sided clear quartz windows. The chamber was housed within a dark compartment to avoid stray light interference. The probe was operated using a microcontroller (Arduino Uno Revision 3) that has been programmed with the analytical response and the working algorithm of the electronics. The probe was sourced with a 12 V rechargeable battery pack and the analytical readouts were given directly using a LCD display panel. Analytical optimisations of the ZnO quantum dots system and the probe have been performed and further described. The probe was found to have a linear response range up to 0.45 mM (R(2)=0.9930) towards copper (II) ion with a limit of detection of 7.68×10(-7) M. The probe has high repeatable and reliable performance.

  19. Facilitated Transport of Ethylene in Poly (Amide 12-Block Tetramethylenoxide) Copolymer/AgBF4 Membranes Containing Silver (I) and Copper (I) Ions as Carriers

    Science.gov (United States)

    Ben Hamouda, Sofiane; Trong Nguyen, Quang; Langevin, Dominique; Roudesli, Sadok

    Metal-incorporated poly(amide 12-block-tetramethylenoxide) (PA12-co-PTMO) copolymer was used for studying facilitated transport of olefines through new composite membranes. The metals incorporated were silver {Ag(I)} and copper {Cu(I)}. Tests were carried out at room temperature (25±2°C) to determine the selectivity and permeability of these membranes to ethylene and ethane gas. The membranes prepared by mixing in solution the copolymer with silver (AgBF4) or copper (CuBF4) salt show a ethylene/ethane selectivity much higher than that of pure PA12-co-PTMO. The membranes were also characterized by Fourier Transform Infra Red (FTIR) spectroscopy and Scanning Electron Microscopy (SEM) in order to understand the structural feature responsible for the observed behaviour. The IRFT spectrum indicate that Ag+ and Cu+ ions are developing interactions with the copolymer. The permeation results obtained with copper containing membranes show that CuBF4 salt introduction in the copolymer tends to reduce ethane permeability. This phenomenon is explained by a diminution of the free volume caused by a decrease of the interchain distance due to the formation of metal ions-polymer matrix complexes. At the same time, for ethylene, the decrease in permeability observed at low salt content is recouped rapidly, when the salt content increases, by a dramatic increase of the permeability which attains 10 times that of the pure PA12-co-PTMO. This behaviour is attributed to the facilitated transport mechanism of the ethylene molecules able to develop specific interactions with the incorporated metal ions. It results from these two antagonistic phenomena a multiplication by 18 of the ethylene/ethane selectivity of the pure copolymer when the CuBF4 content of the composite attains 60%.

  20. Fluorescence enhancement of CdTe/CdS quantum dots by coupling of glyphosate and its application for sensitive detection of copper ion

    Energy Technology Data Exchange (ETDEWEB)

    Liu Zhengqing; Liu Shaopu; Yin Pengfei [Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); He Youqiu, E-mail: heyq@swu.edu.cn [Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China)

    2012-10-01

    Graphical abstract: Glyphosate (Glyp) had been used to modify the surface of CdTe/CdS QDs, resulting in the enhancement of fluorescence intensity. The Glyp-functionalized QDs fluorescent probe offers good sensitivity and selectivity for detecting Cu{sup 2+} based on the fluorescence quenching. Highlights: Black-Right-Pointing-Pointer Water soluble CdTe/CdS quantum dots capped with glyphosate were firstly synthesized. Black-Right-Pointing-Pointer The fluorescence of the Glyp-functionalized QDs was quenched by copper ion. Black-Right-Pointing-Pointer A new fluorescent sensor for copper ion was developed based on the prepared QDs. Black-Right-Pointing-Pointer The sensor exhibited high sensitivity and good selectivity for copper ion. - Abstract: A novel fluorescent probe for Cu{sup 2+} determination based on the fluorescence quenching of glyphosate (Glyp)-functionalized quantum dots (QDs) was firstly reported. Glyp had been used to modify the surface of QDs to form Glyp-functionalized QDs following the capping of thioglycolic acid on the core-shell CdTe/CdS QDs. Under the optimal conditions, the response was linearly proportional to the concentration of Cu{sup 2+} between 2.4 Multiplication-Sign 10{sup -2} {mu}g mL{sup -1} and 28 {mu}g mL{sup -1}, with a detection limit of 1.3 Multiplication-Sign 10{sup -3} {mu}g mL{sup -1} (3{delta}). The Glyp-functionalized QDs fluorescent probe offers good sensitivity and selectivity for detecting Cu{sup 2+}. The fluorescent probe was successfully used for the determination of Cu{sup 2+} in environmental samples. The mechanism of reaction was also discussed.

  1. Direct write of copper-graphene composite using micro-cold spray

    Directory of Open Access Journals (Sweden)

    Sameh Dardona

    2016-08-01

    Full Text Available Direct write of a new class of composite materials containing copper and graphene in the powder phase is described. The composite was synthesized using batch electroless plating of copper for various times onto Nano Graphene Platelets (NGP to control the amount of copper deposited within the loosely aggregated graphene powder. Copper deposition was confirmed by both Focused Ion Beam (FIB and Auger electron spectroscopic analysis. A micro-cold spray technique was used to deposit traces that are ∼230 μm wide and ∼5 μm thick of the formulated copper/graphene powder onto a glass substrate. The deposited traces were found to have good adhesion to the substrate with ∼65x the copper bulk resistivity.

  2. A variable hydrophobic surface improves corrosion resistance of electroplating copper coating

    Science.gov (United States)

    Xu, Xiuqing; Zhu, Liqun; Li, Weiping; Liu, Huicong

    2011-04-01

    In this paper, Cu/liquid microcapsule composite coating was prepared by electroplating method. And a variable hydrophobic surface was obtained due to the slow release of microcapsules and the rough surface. The hydrophobic property and corrosion resistance of the composite was investigated by means of water contact angle instrument and electrochemical technique, respectively. The results suggest that the contact angle (CA) of composite increases gradually with the increasing storing time, and the stable super-hydrophobic property was exhibited after storing in air for 15 days. Meanwhile, the excellent corrosion resistance was displayed, which could be ascribed to the good stability of hydrophobic film on composite surface.

  3. Copper Status of Exposed Microorganisms Influences Susceptibility to Metallic Nanoparticles

    Science.gov (United States)

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

    2017-01-01

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

  4. Chromate (CrO(4)(2-)) and copper (Cu2+) adsorption by dual-functional ion exchange resins made from agricultural by-products.

    Science.gov (United States)

    Marshall, Wayne E; Wartelle, Lynda H

    2006-07-01

    Ion exchange resins commonly have a single functionality for either cations or anions. Resins that have a dual functionality for both cations and anions are uncommon. The objective of this study was to create dual-functional ion exchange resins derived from soybean hulls, sugarcane bagasse and corn stover. Dual-functional resins were prepared by two separate two-step processes. In the first two-step process, by-products were reacted with a solution of citric acid in order to impart additional negative charge, and then reacted with the cross-linking reagent dimethyloldihydroxyethylene urea (DMDHEU) and a quaternary amine (choline chloride) to add positive charge to the lignocellulosic material. In the second two-step process, the order of reaction was reversed, with positive charge added first, followed by the addition of negative charge. These combined reactions added both cationic and anionic character to the by-products as evidenced by the increased removal from solution of copper (Cu(2+)) cation and the chromate (CrO(4)(2-)) anion compared to unmodified by-products. The order of reaction appeared to slightly favor the functionality that was added last. That is, if negative charge was added last, the resulting resin sequestered more copper ion than a comparable resin where the negative charge was added first and vice-versa. Cu(2+) and CrO(4)(2-) were used as marker ions in a solution that contained both competing cations and anions. The dual-functional resins adsorbed as much as or more of the marker ions compared to commercial cation or anion exchange resins used for comparison. None of the commercial resins exhibited dual-functional properties to the same extent as the by-product-based resins.

  5. Lowering the resistivity of polyacrylate ion-selective membranes by platinum nanoparticles addition.

    Science.gov (United States)

    Jaworska, Ewa; Kisiel, Anna; Maksymiuk, Krzysztof; Michalska, Agata

    2011-01-01

    The effect of platinum nanoparticles introduction into polyacrylate membranes was examined. Platinum nanoparticles were added to the membrane cocktail before photopolymerization of the poly(n-butyl acrylate) based ion-selective membranes. Thus obtained sensors were characterized with significantly lowered electrical resistance and increased stability of potential readings compared to classical poly(n-butyl acrylate) membranes. The analytical parameters of platinum nanoparticle containing membranes were well comparable with those of classical membranes.

  6. Effect of Ce+ Ion Implantation upon Oxidation Resistance of Superalloy K38G

    Institute of Scientific and Technical Information of China (English)

    Qian Yuhai; Li Meishuan; Duo Shuwang; Zhao Youming

    2005-01-01

    The oxidation behavior (isothermal and cyclic oxidation) of cast superalloy K38G and the effect of Ce+ ion implantation with dose of 1×1017 ions/cm2 upon its oxidation resistance at 900 and 1000 ℃ in air were investigated. Meanwhile, the influence of Ce+ implantation on oxidation behavior of K38G with pre-oxide scale at 1000 ℃ in air was compared. The pre-oxidation was performed at 1000 ℃ in static air for 0.25 and 1.5 h, respectively. It is shown that the homogeneous external mixture oxide of rutile TiO2+Cr2O3 and non-continuous internal oxide of Al2O3 are formed during the oxidation procedure in all the cases. The isothermal oxidation resistance and the cracking or spallation resistance of superalloy K38G implanted with Ce+ by both of the two different implantation ways are not improved notably. This may be attributed to the mixed oxide composition characteristics and the blocking effect differences of Ce+ segregation along the oxide grain boundaries on the transport process for different diffusing ions.

  7. Helium ion beam lithography (HIBL) using HafSOx as the resist

    Science.gov (United States)

    Luo, Feixiang; Manichev, Viacheslav; Li, Mengjun; Mitchson, Gavin; Yakshinskiy, Boris; Gustafsson, Torgny; Johnson, David; Garfunkel, Eric

    2016-03-01

    Helium ion beam lithography (HIBL) is a novel alternative lithographic technique with the capacity of fabricating highresolution and high-density features. Only limited research has been performed exploring HIBL to date. HafSOx (Hf(OH)4-2x-2y(O2)x(SO4)y·qH2O) is a negative-tone inorganic resist that is one of several candidate resist materials for extreme ultraviolet lithography (EUVL) and e-beam lithography (EBL), and has been demonstrated to show high resolution, moderate sensitivity and low line-edge roughness (LER) in both EUVL and EBL. To date, no ion beam lithography work on HafSOx has been reported. In this study, we tested HafSOx as an HIBL resist and achieved a high sensitivity compared with EBL with a turn-on dose D100 ~ 2-4 μC/cm2. We obtained sub-10 nm line widths with low LER. A simple Monte Carlo simulation suggests that ionizing excitation accounts for most of the incident He ions' energy loss.

  8. Sheet resistance of alumina ceramic after high energy implantation of tantalum ions

    Energy Technology Data Exchange (ETDEWEB)

    Savkin, Konstantin P., E-mail: savkinkp@mail2000.ru [Institute of High Current Electronics SB RAS, 2/3 Akademichesky Avenue, 634055 Tomsk (Russian Federation); Bugaev, Alexey S., E-mail: bugaev@opee.hcei.tsc.ru [Institute of High Current Electronics SB RAS, 2/3 Akademichesky Avenue, 634055 Tomsk (Russian Federation); Nikolaev, Alexey G., E-mail: nik@opee.hcei.tsc.ru [Institute of High Current Electronics SB RAS, 2/3 Akademichesky Avenue, 634055 Tomsk (Russian Federation); Oks, Efim M., E-mail: oks@opee.hcei.tsc.ru [Institute of High Current Electronics SB RAS, 2/3 Akademichesky Avenue, 634055 Tomsk (Russian Federation); Shandrikov, Maxim V., E-mail: shandrikov@opee.hcei.tsc.ru [Institute of High Current Electronics SB RAS, 2/3 Akademichesky Avenue, 634055 Tomsk (Russian Federation); Yushkov, Georgy Yu., E-mail: gyushkov@mail.ru [Institute of High Current Electronics SB RAS, 2/3 Akademichesky Avenue, 634055 Tomsk (Russian Federation); Tyunkov, Andrey V., E-mail: tyunkov@opee.hcei.tsc.ru [Tomsk State University of Control Systems and Radioelectronics, 40 Lenin Avenue, 634050 Tomsk (Russian Federation); Savruk, Elena V., E-mail: savruk@mail.ru [Tomsk State University of Control Systems and Radioelectronics, 40 Lenin Avenue, 634050 Tomsk (Russian Federation)

    2014-08-15

    Highlights: • Tantalum ions with the average energy about 145 keV were implanted in the surfaces of flat polycrystalline alumina samples. • The sheet resistance of implanted ceramic reduced after implantation with increasing of the implanted dose. • Normalized surface conductivity of treated alumina ceramic reduced only on 1% during 200 days after finishing the implantation process. • Creation of weak conducting layer on the surface of the ceramic insulator electric field strength of the flashover increases more than 25%. - Abstract: The results of investigation of the sheet resistance of alumina ceramic as a function of the fluence of implanted metal ions are presented. Tantalum ions with the average energy about 145 keV were used in experiments. Estimation of the sheet resistance was performed from analysis of volt–ampere characteristics by measuring the leakage current at a voltage between 100 V and several kilovolts, which was applied at a small area of the implanted surface. Energy dispersive X-ray analysis was used to determine composition of elements in the surface of the implanted ceramics. As a practical application of research results, it was shown that, after the creation of a weak conducting layer on the surface of the ceramic insulator, the electric field strength of the flashover increases by more than 25%.

  9. Genome sequence of the copper resistant and acid-tolerant Desulfosporosinus sp. BG isolated from the tailings of a molybdenum-tungsten mine in the Transbaikal area

    Directory of Open Access Journals (Sweden)

    Olga V. Karnachuk

    2017-03-01

    Full Text Available Here, we report on the draft genome of a copper-resistant and acidophilic Desulfosporosinus sp. BG, isolated from the tailings of a molybdenum-tungsten mine in Transbaikal area. The draft genome has a size of 4.52 Mb and encodes transporters of heavy metals. The phylogenetic analysis based on concatenated ribosomal proteins revealed that strain BG clusters together with the other acidophilic copper-resistant strains Desulfosporosi