Characteristics of Plant Communities and Copper Content in Dominant Plants in Hongtou Shan Copper Ore Region of Liaoning Province

Copper content in the soil of Hongtou Shan copper ore is 40–2000 ppm, with mean value at 471 ppm. Standard deviation is 667.5. There are many principal types of plant communities: Coppice of Quercus liaotungensis and Corylus sp. and Lespedeza bicolor scrub. In the soli with copper content more than 500 ppm, Gypsophila pacffica usually grows together. It significantly indicates the abnormal soil with respect to copper content. Analysis of copper content for 347 samples of 48 species shows: Limiting value of copper content is 8.45–44.40 ppm in dry plants, with difference of the values being 35.95. The plants contained copper at 5–10 ppm account for 12.8% of the total plants, at 10–30 ppm for 76.9% and at 30–45 ppm for 10.6%. Direct correlation is found between copper content in the Plants and in the soil, for example, Gypsophila pacifiea r=0.844 (N=8) It is important in biogeoehemical prospecting. There are no striking correlation between copper content of the plants and pH and organic matter content of soil.     

Comparison of Leaching of Copper–Nickel Concentrates and Metallurgical Slag with Biogenic Ferric Iron

Applied Biochemistry and Microbiology - The leaching of nonferrous metals from copper–nickel sulfide concentrates and copper–nickel slags with ferric sulfate solution obtained by...     

Associations Between Copper and Zinc and Risk of Hypertension in US Adults

Evidence linking copper and zinc to hypertension are limited and conflicting. Data from the National Health and Nutrition Examination Survey (NHANES) 2007–2014 were used. Zinc and copper intake from diet and supplements was assessed with 24-h dietary recall. Hypertension was defined as systolic blood pressure (SBP) ≥?140 mmHg/diastolic blood pressure (DBP) ≥?90 mmHg/treatment with hypertensive medications. In a sensitivity analysis, according to the 2017 American College of Cardiology and American Heart Association guideline, hypertension was also defined as SBP ≥?130 mmHg/DBP ≥?80 mmHg/treatment with hypertensive medications. A total of 17,811 adults (8430 men and 9381 women) were included. After adjustment for age, gender, body mass index (BMI), race, educational level, smoking status, family income, and total daily energy intake, the OR of hypertension for highest vs. lowest quartile intake of copper, zinc, and copper/zinc ratio was 1.11 (0.90–1.37), 1.11 (0.90–1.35), and 0.95 (0.81–1.11), respectively. In stratified analysis by BMI (<?25 kg/m², 25–30 kg/m², >?30 kg/m²), no significant association was found between hypertension and intakes of copper, zinc, and copper/zinc ratio (highest vs. lowest quartile) in multivariate analysis. In multivariate analysis, the OR of hypertension for highest vs. lowest quartile levels of serum copper, zinc, and copper/zinc ratio was 1.11 (0.61–2.04), 1.43 (0.84–2.44), and 0.68 (0.34–1.33), respectively. Similar results were found in the sensitivity analysis. Zinc and copper might be not independently associated with hypertension in US adults.     

Insight in the transport behavior of copper glycinate complexes through the porcine gastrointestinal membrane using an Ussing chamber assisted by mass spectrometry analysis

An Ussing chamber study was conducted in order to investigate the transport behavior of copper glycinate complexes through a porcine gastrointestinal membrane. Organic copper complexes such as copper tri- and tetraglycinates (GGG–Cu(II) and GGGG–Cu(II)) were used as model system. In a novel analytical approach the Ussing chamber was combined with mass spectrometry. Therefore, relevant analytical methods based on MALDI-MS and a coupling of capillary electrophoresis to ICP-MS and ESI-MS were developed for the determination of copper complexes in the mucosal and serosal half-chambers. It was found that 86.1±8.5% of copper triglycinate but only 20.8±9.9% of copper tetraglycinate penetrated the digestive membrane without modification. Furthermore, inorganic copper species were not detected but a new copper complex (m/z 442) was found to be formed in both compartments of the Ussing chamber.     

Increased generation of intracellular reactive oxygen species initiates selective cytotoxicity against the MCF-7 cell line resultant from redox active combination therapy using copper–thiosemicarbazone complexes

The combination of cytotoxic copper–thiosemicarbazone complexes with phenoxazines results in an up to 50-fold enhancement in the cytotoxic potential of the thiosemicarbazone against the MCF-7 human breast adenocarcinoma cell line over the effect attributable to drug additivity—allowing minimization of the more toxic copper–thiosemicarbazone component of the therapy. The combination of a benzophenoxazine with all classes of copper complex examined in this study proved more effective than combinations of the copper complexes with related isoelectronic azines. The combination approach results in rapid elevation of intracellular reactive oxygen levels followed by apoptotic cell death. Normal fibroblasts representative of non-cancerous cells (MRC-5) did not display a similar elevation of reactive oxygen levels when exposed to similar drug levels. The minimization of the copper–thiosemicarbazone component of the therapy results in an enhanced safety profile against normal fibroblasts.     

Diamagnetic dilution due to the phase spin transition – An opportunity for the EPR study of intercluster exchange in “breathing” crystals of copper(II) hexafluoroacetylacetonate with pyrazole-substituted nitronyl nitroxide

Chain complex of copper(II) hexafluoroacetylacetonate with pyrazole-substituted nitronyl nitroxide containing exchange-coupled copper(II)–nitroxide clusters has been studied using electron paramagnetic resonance (EPR) spectroscopy. The structural rearrangements at low temperatures induce spin transitions in one half of the copper(II)–nitroxide clusters and effectively lead to reversible diamagnetic dilution. This results in significant changes of EPR spectra and allows us to obtain the value of dipole–dipole interaction in exchange-coupled spin pair as well as the value of exchange interaction between neighboring pairs.     

Element bioimaging of liver needle biopsy specimens from patients with Wilson’s disease by laser ablation-inductively coupled plasma-mass spectrometry

A laser ablation–inductively coupled plasma–mass spectrometry (LA–ICP–MS) method is developed and applied for the analysis of paraffin-embedded liver needle biopsy specimens of patients with Wilson’s disease (WD), a rare autosomal recessive disorder of the copper metabolism causing various hepatic, neurological and psychiatric symptoms due to a copper accumulation in the liver and the central nervous system. The sample set includes two WD liver samples and one negative control sample. The imaging analysis was performed with a spatial resolution of 10 μm. Besides copper, iron was monitored because an elevated iron concentration in the liver is known for WD. In addition to this, both elements were quantified using an external calibration based on matrix-matched gelatine standards. The presented method offers low limits of detection of 1 and 5 μg/g for copper and iron, respectively. The high detection power and good spatial resolution allow the analysis of small needle biopsy specimen using this method. The two analyzed WD samples can be well differentiated from the control sample due to their inhomogeneous copper distribution and high copper concentrations of up to 1200 μg/g. Interestingly, the WD samples show an inverse correlation of regions with elevated copper concentrations and regions with high iron concentrations.     

The effect of phospholipid depletion on the EPR behavior of cytochrome oxidase

Phospholipids are essential components for electron transport activity of cytochrome oxidase. Recently, we have found that the removal of phospholipids from the oxidase affected the copper and low-spin heme signals, and conceivably other paramagnetic centers as demonstrated by EPR spectroscopy. At 4.2–30 °K, the signal amplitudes and power saturation behaviors were studied at approximately g = 2.0 for the copper signal, and in the neighborhood of g = 3.0 for the low-spin heme signal. After depletion of phospholipids the amplitude of the copper signal decreased 25–30% at 12–30 °K and below 12 °K 40–50% under nonsaturating conditions. The amplitude of the low-spin heme signal decreased 60–70% at 4.2–20 °K. Below 14 °K both signals became more resistant to power saturation, but the copper signal was more readily saturated above this temperature, compared to the oxidase with about 25% lipid. After removal of phospholipids, the spectral features of the copper signal remained essentially the same, but the low-spin heme signal broadened and became very asymmetric to show two signals as revealed by the second harmonic EPR spectra. These findings may explain, at least partially, the wide variations in percentage of EPR detectable copper and heme of cytochrome oxidase reported by different laboratories. Unequivocally, the EPR behavior of cytochrome oxidase is not only affected by the protein moiety, but also by the associated phospholipids of the enzyme.     

The copper (II) ion as a carrier for the antibiotic capreomycin against Mycobacterium tuberculosis

In recent years, the bacterium responsible for tuberculosis has been increasing its resistance to antibiotics resulting in new multidrug resistant Mycobacterium tuberculosis (MR-TB) and extensively drug-resistant tuberculosis (XDR-TB). In this study we use several analytical techniques including NMR, FT-ICR, TOF-MS, LC–MS and UV/Vis to study the copper–capreomycin complex. The copper (II) cation is used as a carrier for the antibiotic capreomycin. Once this structure was studied using NMR, FT-ICR, and MALDI-TOF-MS, the NIH-NIAID tuberculosis cell line for several Tb strains (including antibiotic resistant strains) were tested against up to seven variations of the copper–capreomycin complex. Different variations of copper improved the efficacy of capreomycin against Tb up to 250 fold against drug resistant strains of Tb.     

Leachability,metal corrosion,and termite resistance of wood treated with copper-based preservative

Health-awareness and concern for the environment have resulted in voluntary removal of chromated copper arsenate (CCA) from wood preservatives in residential applications worldwide. Copper-based preservatives have been formulated as replacements, but these may not provide a permanent solution to all of the related problems, including copper contamination of aquatic environments and corrosion of fasteners. In this study, the copper retention (before and after the leaching process) of five softwood specimens vacuum-treated with alkaline copper quaternary (ACQ) and copper azole (CA) at three target retention levels was investigated by X-ray fluorescence studies. The metal corrosion and termite (Coptotermes formosanus) resistance of treated specimens were studied under laboratory conditions. Except for treated Japanese larch wood, the copper retention levels of the other wood specimens were able to meet the target copper retention values (use classes 2–4) in Chinese National Standard 3000. The copper leaching rates were 6.92–19.54% for ACQ-treated wood and 9.38–22.46% for CA-treated wood. The metal corrosion rates of iron nails due to corrosion tests (CNS 6717) were influenced significantly by the 1.2% ACQ and 1.2% CA treatments; whereas the metal corrosion rates of zinc-galvanized steel nails were less than 2 and could meet the tested standard. Even though the ACQ and CA treatments caused higher copper leaching rates from the treated specimens, they also increased termite mortalities and reduced the mass loss significantly after termite-resistance tests (JIS K 1571).     

The complexation of aqueous metal ions relevant to biological applications. 2. Reactions of copper(II) citrate and copper(II) succinate with selected amino acids

Abstract

Addition of amino acids, glycine, alanine, and serine, to poorly soluble copper(II) salts [copper(II) citrate and copper(II) succinate] all increase solubility of the copper(II) salts. Relative increases in solubility follow the polarity trend in the selected amino acids, with serine creating the greatest increase in solubility. Simultaneous equilibria calculations indicate the formation of mixed-ligand complexes in the copper(II) succinate–amino acid systems, the first time such mixed-ligand complexes have been observed. In contrast, mixed-ligand complexes are not predicted in the copper(II) citrate–amino acid systems. Potential bioavailability of copper(II) appears to be increased by the inclusion of amino acids in solution, roughly in parallel with the increase in solubility of the copper(II) salt. Therefore, measurement of the change in solubility caused by addition of amino acids to aqueous solution gives qualitative insight to the potential increase in bioavailability of the metal ion.     

Copper Nitrate Catalyzed Three-Component One-Pot Synthesis of 3,4-Dihydropyrimidin-2(1H)-Ones

Abstract

An efficient synthesis of 3,4-dihydropyrimidin-2(1H)-ones from aldehydes, 1,3-dicarbonyl compounds, and urea using copper nitrate under refluxing temperature in ethanol was described. Compared with other Lewis copper salts, copper nitrate proved to be the most efficient. The advantages of the new method were good yields (61–93%), short reaction time (0.4–3 h), and inexpensive catalyst.     

Biomethanation of spent wash: Heavy metal inhibition of methanogenesis in synthetic medium

Five heavy metals detected in distillery waste were lead (1.0–8.8 μg/ml), copper (1.7–15.7 μg/ml), zinc (3.1–11.8 μg/ml), iron (36.0–43.5 μg/ml), and manganese (3.0–5.1 μg/ml). Their toxicity to biomethanogenesis in a synthetic medium containing 1% sodium acetate, propionate, or butyrate was measured by batch fermentation, after cultivating the bacterial biomass semicontinuously. Lead, copper, and zinc in decreasing order were found to be toxic to biomethanogenesis. Lead at the concentration of 10 μg/ml completely stopped methane production. Iron did not produce any notable change in the process while manganese stimulated the rate of methane production. The toxicity of lead, copper, and zinc to methanogenic bacteria and methane production was dose-dependent but the growth of acetogenic bacteria was impaired at higher concentrations (2.5–10.0 μg/ml) of lead, copper, and zinc. Manganese stimulated the growth of only methanogenic bacteria, but not that of non-methanogenic bacteria or acetic acid production. The reduction in the synthesis of acetic acid via butyrate was more in the presence of these three metals than the synthesis of this acid via propionate.     

Effects of oxidation on redox and cytotoxic properties of copper complex of Aβ1–16 peptide

Abstract

The effect of oxidation on redox and cytotoxic properties of copper complex of amyloid beta (Aβ) peptide was studied by gamma radiolysis. The oxidation of Aβ1–16 and Aβ1–16/Cu(II) complex was carried out using hydroxyl (^?OH) radicals produced by gamma radiolysis and the products were analyzed using mass spectrometry. The presence of Cu(II) was found to enhance the oxidation of Aβ1–16 peptide. The oxidation of residues Asp1, His6, and His13 was enhanced due to their involvement in copper binding. The oxidation of His residues of Aβ1–16 peptide, which are chiefly responsible for copper binding, resulted in altered redox properties and subsequently in higher cytotoxicity of the Aβ1–16 peptide in SH-SY5Y cells.     

Copper ion as a delivery platform for taxanes and taxane complexes

A number of delivery agents, such as proteins, liposomes, micelles, and nanoparticles, are utilized for transporting pharmaceutical agents in a physiological environment. This Letter focuses on the use of the copper(II) ion and its potential role as a delivery agent for the taxanes and taxol couple to a malaria drug. Nuclear magnetic resonance (NMR, ¹H, ¹³C, ¹⁵N), Mass Spectrometry (LC-MS, MALDI-TOF, FT-ICR) and computational methods are used to examine the structure of the complex. The National Cancer Institute’s benchmark 60 cell line panel is used to compare the efficacy of the copper–taxol and copper–taxol–hydroxychloroquin complexes to that of iron–taxol and pure taxol.     

COPPER TOLERANCE OF CHLAMYDOMONAS ACIDOPHILA (CHLOROPHYCEAE) ISOLATED FROM ACIDIC,COPPER-CONTAMINATED SOILS1

Cells of Chlamydomonas acidophila Negoro, isolated from three soils with different available copper contents (74, 80, and 87 μg·g^?1), were assayed for their responses to copper. Soil pH ranged from 3.3–3.9. Responses were evaluated using algistatic assays involving five day exposure to copper concentrations from 0.1–100 mg·L^?1 at pH 3.8 and 6.6 in defined liquid media. Interspecies and intraspecies comparisons were made between the soil isolates and laboratory strains of C. reinhardtii and C. acidophila, respectively. Algistatic copper concentrations of soil isolates were 20–125 times greater than those of the laboratory strain of C. reinhardtii. Concentrations of 0.1 mg Cu·L^?1, or greater, killed the laboratory strain of C. acidophila. Soil isolates of C. acidophila appeared to be copper tolerant; however, there was no conclusive evidence to indicate that the level of copper tolerance in the soil isolates was positively correlated with the level of available copper in the soil.     

A chemiluminescent metalloimmunoassay based on copper‐enhanced gold nanoparticles for quantification of human growth hormone

A chemiluminescence (CL) immunoassay was developed to determine human growth hormone (hGH) based on copper‐enhanced gold nanoparticles. In this method, gold nanoparticles were deposited on polystyrene wells for adsorption of human growth antibodies as well as catalyst for reducing of copper ions from the copper enhancer solution. The reduction of copper ions was prevented where the gold nanoparticles were covered by the antibody–antigen immunocomplex. The deposited copper on Au nanoparticles was then dissolved in HNO₃ solution and quantified using the CL method. The CL intensity response was logarithmically dependent on the hGH concentrations over the range 0.2–50 ng/mL, with a detection limit (3σ) of 0.036 ng/mL. Copyright © 2012 John Wiley & Sons, Ltd.     

Antimicrobial properties of ternary eutectic aluminum alloys

Several Escherichia coli deletion mutants of the Keio collection were selected for analysis to better understand which genes may play a key role in copper or silver homeostasis. Each of the selected E. coli mutants had a deletion of a single gene predicted to encode proteins for homologous recombination or contained functions directly linked to copper or silver transport or transformation. The survival of these strains on pure copper surfaces, stainless steel, and alloys of aluminum, copper and/or silver was investigated. When exposed to pure copper surfaces, E. coli ΔcueO was the most sensitive, whereas E. coli ΔcopA was the most resistant amongst the different strains tested. However, we observed a different trend in sensitivities in E. coli strains upon exposure to alloys of the system Al–Ag–Cu. While minor antimicrobial effects were detected after exposure of E. coli ΔcopA and E. coli ΔrecA to Al–Ag alloys, no effect was detected after exposure to Al–Cu alloys. The release of copper ions and cell-associated copper ion concentrations were determined for E. coli ΔcopA and the wild-type E. coli after exposure to pure copper surfaces. Altogether, compared to binary alloys, ternary eutectic alloys (Al–Ag–Cu) had the highest antimicrobial effect and thus, warrant further investigation.     

Effects of some trace elements on the blood of Kuwait mullets, Liza Macrolepis (Smith)

Haemopathological changes attributed to heavy metal poisoning were observed in blood smears of Liza macrolepis (Smith) taken after exposures of 96 h to graded doses (mg/l) of copper (0.11–1.80), lead (1.15–18.36), and mercury (0.04–0.59), in a flow-through marin bioassay system. In general, changes in leucocytic profile appear to be correlated with pathological changes caused by increasing copper and mercury concentrations. By contrast, blood samples of mullets exposed to lead, showed significant polychromasia and + anisocytosis regardless of concentrations. The RBC count, haemoglobin content, and haemotocrit percentages were less valuable in diagnosis of copper and mercury effects.These manifestations of poisoning by trace elements bear a resemblance to the pathological changes that have been shown clinically and experimentally in mammals. Consequently, blood measurements on marine organisms may be diagnostic of undeirably high levels of copper and mercury, and so may constitute useful indicators of marine pollution.     

Tissue-and metal-specific effects of thiolacrylic acids in rats

Kidney copper increased 12- to 18-fold above the normal level in rats administered alpha-mercapto-beta-(2-furyl)acrylic acid (MFA). Kidney zinc increased twofold; plasma zinc increased more than 10-fold and liver zinc increased 30–50%. No other changes in copper, iron, and zinc concentrations were found in these tissues or in bone, brain, heart, lung, skeletal muscle, spleen, or testis. Related compounds produced similar effects, although MFA and its disulfide were the most potent of the compounds tested. These increases in tissue copper and zinc were largely complete after 2–5 d of daily administration of compound. Increased plasma zinc returned toward normal with a half-life of 1.0 d for the process, after dosing was ended; albumin was identified as the species binding the excess zinc in plasma. Kidney copper and zinc, which had increased in the ratio of 3 Cu/Zn, returned to normal levels after dosing was stopped with half-lives of 2.1–2.5 d. Consistent with the observations of highly tissuespecific effects of MFA, copper and zinc balances over 8 weeks of trials were found to be not greatly affected by administration of the compound. Thus, it was not established whether excess metal in affected organs derived from enhanced retention of dietary metal or redistribution from other tissues. Kidney copper and zinc and serum zinc increased even in zinc-deficient rats administered MFA.