An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
... An efficient synthetic organic transformation was developed to access isoquinoline-substituted isobenzofurans by reaction of substituted 1,5-diynes with isoquinoline N-oxides. Moderate to excellent yields of isoquinoline-derived isobenzofurans were achieved by formation of a new C–C and two C–O bonds in the presence of copper catalyst in one pot. whereas quinoline-substituted isobenzofurans were o ...
... Plastic waste is an environmental problematic, not only because of its own contamination, but also because it can act as a vector for other pollutants, particularly metals. In this work, taking advantage of the sensitivity of the LIBS technique, the presence of copper in plastics and microplastics present in a stream that receives effluents from a medium-sized city was determined. The influence of ...
copper; copper metabolism, etc ; Schizosaccharomyces pombe; amino acid sequences; iron; ligands; microbiology; oxidoreductases; toxicity; Show all 9 Subjects
Abstract:
... Iron is an essential trace metal ion required for all living organisms, and is taken up by iron transporters. Here, we identified and characterized three-candidate high-affinity (Fio1, Frp1 and Frp2) and two-candidate low-affinity iron transporters (Fet4 and Pdt1) from the fission yeast Schizosaccharomyces pombe. Protein sequence analyses revealed that Fio1 is a multicopper oxidase that contains t ...
copper; copper sulfate, etc ; Burkholderia cepacia; bioremediation; color; decolorization; genes; methylene blue; nucleotide sequences; wastewater; Show all 10 Subjects
Abstract:
... Irawati W, Lindarto V, Pinontoan R, Yuwono T, Mangunsong FM, Silalahi DW. 2022. Burkholderia cepacia strain IrV1 multi-resistant to copper and dyes isolated from laboratory wastewater effluent. Biodiversitas 23: 2614-2620. Copper and dye multi-resistant bacteria may be cultivated to increase the efficiency of waste bioremediation processes. Multi-resistant bacteria can be isolated from waste conta ...
copper; copper nanoparticles, etc ; aquaculture; aquatic environment; bioaccumulation; biofouling; cages; fish; innovation adoption; polyaniline; polyethylene; Show all 11 Subjects
Abstract:
... Biofouling is a major issue in aquaculture cages and nano materials based antifouling strategies became more prominent in recent years. Polyethylene aquaculture cage net surface which is modified with polyaniline and nano-copper oxide (CuO), reported to have biofouling resistance. Leaching of nano CuO from the net to the aquatic environment and its bioaccumulation in fish is the major concern agai ...
... The extensive use of copper-based fungicides in orchards, especially in vineyards, leads to the accumulation of copper, which has caused growing concern. However, data on the acquisition of antibiotic resistance in opportunistic pathogens under copper-based fungicides are scarce. In this study, we investigated the potential development of antibiotic resistance in Escherichia coli K12 under selecti ...
... Drinking-water contamination with nitrate ions is inevitable and wide spreading, which demands feasible removal. Water de-nitration by potentiostatic electroreduction is described here. A novel electrocatalyst based on nano-copper particles, supported onto multi-walled carbon nanotubes (MWCNTs), and spray-deposited onto fluorine doped tin oxide-glass substrates, is described. The Cu/MWCNT/FTO elec ...
... An efficient annulation method for the synthesis of polysubstituted dihydrofurans from 1,3-dicarbonyl compounds and maleimides is described. The reactions can afford furo[2,3-c]pyrrole derivatives with satisfactory yields. The developed strategy realizes the direct oxidative double C(sp³)–H functionalization in the presence of copper(I) salts and 2-(tert-butylperoxy)-2-methylpropane. Meanwhile, th ...
... In recent years, there has been growing interest in the mechanism (radical or nonradical) of persulfate activation processes. In this study, the enhancement of naproxen (NPX) degradation in a Cu⁰/peroxymonosulfate (PMS) system by complexing reagents was investigated. Surprisingly, neocuproine (NCP) alters the nature of reactive species in the Cu⁰/PMS system. A high-valent copper species, Cu(III)-N ...
copper, etc ; absorption; electromagnetic radiation; nanocomposites; Show all 4 Subjects
Abstract:
... The preparation of hollow materials is one of the most feasible ways to obtain efficient electromagnetic wave (EMW) absorbers. Herein, using the copper-based metal–organic frameworks (Cu-MOF-74) as templates, hollow copper-based sulfides with various morphologies (rod-like, cubic, and dodecahedral) were designed and synthesized. The outer Cu₂S and/or Cu₃₁S₁₆ shell possesses excellent electronic co ...
copper, etc ; alloys; microstructure; oxidation; oxygen; Show all 5 Subjects
Abstract:
... Herein, CoCrₓCuFeMnNi (x = 0, 0.5, 1.0, 1.5, and 2.0, in molar ratio) high-entropy alloys (HEAs) are fabricated by vacuum hot-pressing sintering (VHPS). The effect of Cr content on the microstructure and oxidation behavior are studied. When x ≤ 1.5 mol, the phases of the four alloys were all composed of FCC2 major phase and FCC1 secondary phase, while Cr₂.₀ alloy consisted of a small amount of FCC ...
... Copper-based chalcogenide semiconductors are particularly attractive materials for photovoltaic and nonlinear optical applications. Unfortunately, accurate theoretical understanding of the optical responses of these materials is hindered by the presence of strongly localized Cu 3d electrons. To assess the validity of calculation schemes for determining the optical properties of Cu-based chalcogeni ...
copper nanoparticles, etc ; alkenes; catalysts; durability; nanosheets; Show all 5 Subjects
Abstract:
... Utilizing heterogeneous catalysts to overcome obstacles for homogeneous reactions is fascinating but very challenging owing to the difficult fabrication of such catalysts based on the character of target reactions. Herein, we report a Al³⁺ doping strategy to construct single-atom Cu on MgO nanosheets (Cu₁/MgO(Al)) for boosting the free-radical hydrophosphinylation of alkenes. Al³⁺ dopants in MgO b ...
copper, etc ; carbenes; diazo compounds; organic chemistry; Show all 4 Subjects
Abstract:
... A concise synthetic route to spiroindoline-fused S-heterocycles was developed through copper-catalyzed [4 + 1] annulation using enaminothiones as donor–acceptor synthons. Both 3-diazoindolin-2-imines and 3-diazooxindoles were amenable to work as effective C1 building blocks. The reaction proceeds via a copper-catalyzed cascade process involving the in situ generation of copper(I) carbene and C–S/C ...
... Green synthesis of copper oxide nanoparticles (CuONPs) was performed using Sesbania aculeata leaf extract. The characteristics of CuONPs were studied using the selected area electron diffraction analysis. The effect of nanoparticles on the plant growth including germination efficiency was studied in Brassica nigra at different concentrations (25, 30, 100 mg/100 ml) using plant tissue culture techn ...
copper; copper nanoparticles, etc ; X-ray photoelectron spectroscopy; decontamination; environment; equations; nitrates; pH; sorbents; temperature; thermodynamics; thorium; uranium; water treatment; Show all 14 Subjects
Abstract:
... The removal of radioactive contaminants from aquifers is a matter of great concern. In this paper, coated copper-based nanoparticles (Cu-based NPs) were investigated as sorbent materials to remove uranium and thorium from low-level wastes, and especially from water, considering the influences of temperature, time, concentration, and pH. Cu-based NPs were derived through a hydrothermal synthesis fr ...
... Inhalation exposure to copper may occur during a range of occupational activities and the purpose of this study was to characterise the toxicological response to repeated inhalation of two copper compounds, representative of copper substances in large-scale production/use. Crl:CD(SD) rats were repeatedly exposed to aerosols of dicopper oxide (Cu₂O) or copper sulphate pentahydrate (CuSO₄.5 H₂O) for ...
copper nanoparticles, etc ; carbon dioxide; comparative study; electrochemistry; Show all 4 Subjects
Abstract:
... Herein, we demonstrated how the processing routes of OD-Cu affected the surface structure and electrochemical reduction of CO₂. We found that the OD-Cu obtained by H₂ annealing is large Cu nanoparticles (>100 nm) while the OD-Cu processed by electrochemical reduction possesses a porous structure of aggregated small Cu + Cu₂O nanoparticles (∼5 nm). These structural differences lead to a distinct pe ...
copper, etc ; Bacillus subtilis; Gram-positive bacteria; peptidoglycans; Show all 4 Subjects
Abstract:
... In the original paper, Chang and co-workers describe the contact killing of Bacillus subtilis, a Gram-positive bacterium, on copper-containing substrates and offer a mechanism for its accomplishment. The present Comment offers support for that mechanism and adds a necessary initial step, the degradation of the overlying peptidoglycan lattice. Degradation is necessary because the lattice is too thi ...
copper, etc ; Lewis acids; cyclization reactions; ligands; phosphine; Show all 5 Subjects
Abstract:
... A new series of C₁-symmetric P-chirogenic bisphosphine ligands of the type (R)-5,8-Si-Quinox-tBu₃ (Silyl = SiMe₃, SiEt₃, SiMe₂Ph) have been developed. The bulky silyl modulators attached to the ligand backbone fix the phosphine substituents to form rigid chiral environments that can be used for substrate recognition. The ligand showed high performances for a copper(I)-catalyzed asymmetric borylati ...