Deciphering the effect of a Cu(II)-hydrazone complex on intracellular cell signalling pathways in a human osteosarcoma 2D and 3D models.

New therapeutic strategies for osteosarcoma (OS) have demonstrated the potential efficacy of copper compounds as anticancer drugs and as a substitute for the often used platinum compounds. OS is a type of bone cancer, primarily affecting young adults and children..The main objective of this work is to discover the molecular targets and cellular pathways related to the antitumor properties of a Cu(II)-hydrazone toward human OS  2D and 3D systems. Cell viability study using MG-63 cells was evaluated in OS monolayer and spheroids. CuHL significantly reduced cell viability in OS models (IC50 2D: 2.6 ± 0.3 µM; IC50 3D: 9.9 ± 1.4 µM) (p<0.001). Also, CuHL inhibits cell proliferation and it induces cells to apoptosis. The main mechanism of action found for CuHL are the interaction with DNA, genotoxicity, the ROS generation and the proteasome activity inhibition. Besides, 67 differentially expressed proteins were found using proteomic approaches. Of those 67 proteins, 40 were found overexpressed and 27 underexpressed. The response to stress and to unfolded protein, as well as ATP synthesis were the most affected biological process among upregulated proteins, whilst proteins related to DNA replication and redox homeostasis were downregulated.

A brief review on computer simulations of chalcopyrite surfaces: structure and reactivity.

Chalcopyrite, the world's primary copper ore mineral, is abundant in Latin America. Copper extraction offers significant economic and social benefits due to its strategic importance across various industries. However, the hydrometallurgical route, considered more environmentally friendly for processing low-grade chalcopyrite ores, remains challenging, as does its concentration by froth flotation. This limited understanding stems from the poorly understood structure and reactivity of chalcopyrite surfaces. This study reviews recent contributions using density functional theory (DFT) calculations with periodic boundary conditions and slab models to elucidate chalcopyrite surface properties. Our analysis reveals that reconstructed surfaces preferentially expose S atoms at the topmost layer. Furthermore, some studies report the formation of disulfide groups (S22-) on pristine sulfur-terminated surfaces, accompanied by the reduction of Fe3+ to Fe2+, likely due to surface oxidation. Additionally, Fe sites are consistently identified as favourable adsorption locations for both oxygen (O2) and water (H2O) molecules. Finally, the potential of computer modelling for investigating collector-chalcopyrite surface interactions in the context of selective froth flotation is discussed, highlighting the need for further research in this area.

Multivalent hydrogen-bonded architectures directed by self-complementarity between [Cu(2,2'-biimidazole)] and malonate building blocks.

The synthesis and structural characterization of four novel supramolecular hydrogen-bonded arrangements based on self-assembly from molecular `[Cu(2,2'-biimidazole)]' modules and malonate anions are presented, namely, tetrakis(2,2'-biimidazole)di-µ-chlorido-dimalonatotricopper(II) pentahydrate, [Cu3(C3H2O4)2Cl2(C6H6N4)4]·5H2O or [Cu(H2biim)2(µ-Cl)Cu0.5(mal)]2·5H2O, aqua(2,2'-biimidazole)malonatocopper(II) dihydrate, [Cu(C3H2O4)(C6H6N4)(H2O)]·2H2O or [Cu(H2biim)(mal)(H2O)]·2H2O, bis[aquabis(2,2'-biimidazole)copper(II)] dimalonatodiperchloratocopper(II) 2.2-hydrate, [Cu(C6H6N4)2(H2O)]2[Cu(C3H2O4)(ClO4)2]·2.2H2O or [Cu(H2biim)2(H2O)]2[Cu(mal)2(ClO4)2]·2.2H2O, and bis(2,2'-biimidazole)copper(II) bis[bis(2,2'-biimidazole)(2-carboxyacetato)malonatocopper(II)] tridecahydrate, [Cu(C6H6N4)2][Cu(C3H2O4)(C3H3O4)(C6H6N4)2]·13H2O or [Cu(H2biim)2][Cu(H2biim)2(Hmal)(mal)]2·13H2O. These assemblies are characterized by self-complementary donor-acceptor molecular interactions, demonstrating a recurrent and distinctive pattern of hydrogen-bonding preferences among the carboxylate, carboxylic acid and N-H groups of the coordinated 2,2'-biimidazole and malonate ligands. Additionally, coordination of the carboxylate group with the metallic centre helps sustain remarkable supramolecular assemblies, such as layers, helices, double helix columns or 3D channeled architectures, including mixed-metal complexes, into a single structure.

CuO nanoparticles' effect on the photosynthetic performance in seed tissues of Inga laurina (Fabaceae).

Copper oxide nanoparticles (CuONPs) have been produced on a large scale because they can be applied across various fields, especially in nano-enabled healthcare and agricultural products. However, the increasing use of CuONPs leads to their release and accumulation into the environment. The CuONPs uptaken by seeds and their implications on germination behavior have been reported, but little is known or understood about their impact on photosynthesis in seed tissues. To fill knowledge gaps, this study evaluated the effects of CuONP concentrations (0-300 mg L-1) on the photosynthetic activity of Inga laurina seeds. The microscopy data showed that CuONPs had an average size distribution of 57.5 ± 0.7 nm. Copper ion release and production of reactive oxygen species (ROS) by CuONPs were also evaluated by dialysis and spectroscopy experiments, respectively. CuONPs were not able to intrinsically generate ROS and released a low content of Cu2⁺ ions (4.5%, w/w). Time evolution of chlorophyll fluorescence imaging and laser-induced fluorescence spectroscopy were used to monitor the seeds subjected to nanoparticles during 168 h. The data demonstrate that CuONPs affected the steady-state maximum chlorophyll fluorescence ( F m ' ), the photochemical efficiency of photosystem II ( F v / F m ), and non-photochemical quenching ( NPQ ) of Inga laurina seeds over time. Besides, the NPQ significantly increased at the seed development stage, near the root protrusion stage, probably due to energy dissipation at this germination step. Additionally, the results indicated that CuONPs can change the oscillatory rhythms of energy dissipation of the seeds, disturbing the circadian clock. In conclusion, the results indicate that CuONPs can affect the photosynthetic behavior of I. laurina seeds. These findings open opportunities for using chlorophyll fluorescence as a non-destructive tool to evaluate nanoparticle impact on photosynthetic activity in seed tissues.

Evaluation of adhesive properties and enzymatic activity at the hybrid layer of a simplified adhesive loaded with 0.2 % Cu and 5 % ZnO nanoparticles: A Randomized Clinical Trial and ex vivo analysis.

OBJECTIVE: The aim of this study was to evaluate the effect of an adhesive loaded with 0.2 % copper (Cu) and 5 % zinc oxide (ZnO) nanoparticles (Nps) on its adhesive properties and enzymatic activity at the hybrid layer ex vivo in a randomized clinical model. METHODS: Fifteen patients participated in this study, and a total of 30 third molars were used. Occlusal cavities (4 × 4 × 2 mm) were made in each tooth, and randomly divided into 2 groups: (i) Experimental group: commercial adhesive loaded with 0.2wt % CuNps and 5wt % ZnONps; and (ii) Control Group: non-loaded commercial adhesive. Teeth were restored with resin composite. Thirty days later, extractions were performed. Extracted teeth were longitudinally sectioned. Nps in powder were characterized by field emission scanning electron microscope (FE-SEM) and energy dispersive X-ray (EDX) analysis. Microtensile bond strength (µTBS), degree of conversion (DC), and nanoleakeage (NL) tests were executed. In situ zymography (Zym) was performed to evaluate the gelatinolytic activity at the hybrid layer. Student's t-test (α = 0.05) was applied for all tests. RESULTS: µTBS and DC did not show significant differences (p > 0.05) between both groups. However, NL and gelatinolytic activity at the hybrid layer showed significant values (p < 0.05) for experimental group in comparison with control group. CONCLUSION: The addition of 0.2 % CuNps and 5 % ZnONps to a universal adhesive decreases NL and gelatinolytic activity at the hybrid layer, without jeopardizing its adhesive properties. SIGNIFICANCE: This randomized clinical trial with ex vivo analysis demonstrate that a commercial adhesive modified with 0.2wt % Cu and 5wt % ZnO Nps that does not affect its adhesive properties, reducing gelatinolytic activity and nanoleakage at the hybrid layer, which should contribute to an improvement of long term bonding-dentine clinical performance.

Synthesis and Superficial Modification "In Situ" of Copper Selenide (Cu2-x Se) Nanoparticles and Their Antibacterial Activity.

Copper selenide nanoparticles (Cu2-x Se NPs) have received a lot of attention in recent decades due to their interesting properties and potential applications in various areas such as electronics, health, solar cells, etc. In this study, details of the synthesis and characterization of copper selenide nanoparticles modified with gum arabic (GA) are reported. Also, through transmission electronic microscopy (TEM) analysis, the transformation of the morphology and particle size of copper selenide nanoparticles in aqueous solution was studied. In addition, we present an antimicrobial study with different microorganisms such as Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Candida albiacans (C. albicans). Copper selenide nanoparticles were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry analysis (DSC) and TEM. XRD confirmed the crystal-line structure of the nanoparticles such as cubic berzelanite with a particle size of 6 nm ± 0.5. FTIR and TGA corroborated the surface modification of copper selenide nanoparticles with gum arabic, and DSC suggested a change in the structural phase from cubic to hexagonal. TEM analysis demonstrated that the surface modification of the Cu2-x Se NPs stabilized the nanostructure of the particles, preventing changes in the morphology and particle size. The antimicrobial susceptibility analysis of copper selenide nanoparticles indicated that they have the ability to inhibit the microbial growth of Staphylococcus aureus, Escherichia coli and Candida albicans.

Antimicrobial Activity of Green Synthesized Silver and Copper Oxide Nanoparticles against the Foodborne Pathogen Campylobacter jejuni.

Campylobacter jejuni is a major cause of global foodborne illnesses. To develop alternative antimicrobial strategies against C. jejuni, this study designed and optimized the green synthesis of metallic nanoparticles (NPs) with intracellular components of the medicinal fungus Ganoderma sessile to provide the needed reducing and stabilizing agents. NPs were characterized by transmission electron microscopy and dynamic light scattering, and the quasi-spherical NPs had sizes of 2.9 ± 0.9 nm for the copper oxide NPs and 14.7 ± 0.6 nm for the silver NPs. Surface charge assessment revealed zeta potentials of -21.0 ± 6.5 mV and -24.4 ± 7.9 mV for the copper oxide and silver NPs, respectively. The growth inhibition of C. jejuni by the NPs occurred through attachment to the outer cell membrane and subsequent intracellular internalization and resulted in minimum inhibitory concentrations of the silver NPs at 6 µg/mL and copper oxide NPs at 10 µg/mL. On the other hand, a differential ROS production caused by silver and copper NPs was observed. In summary, this research presents the first demonstration of using green synthesis with the medicinal fungus G. sessile to produce metallic NPs that effectively inhibit C. jejuni growth, providing a sustainable and effective approach to the traditional use of antimicrobials.

Copper Is Accumulated as Copper Sulfide Particles, and Not Bound to Glutathione, Phytochelatins or Metallothioneins, in the Marine Alga Ulva compressa (Chlorophyta).

To analyze the mechanism of copper accumulation in the marine alga Ulva compressa, it was cultivated with 10 µM of copper, with 10 µM of copper and increasing concentrations of a sulfide donor (NaHS) for 0 to 7 days, and with 10 µM of copper and a concentration of the sulfide acceptor (hypotaurine) for 5 days. The level of intracellular copper was determined as well as the level of glutathione (GSH) and phytochelatins (PCs) and the expression of metallothioneins (UcMTs). The level of intracellular copper in the algae treated with copper increased at day 1, slightly increased until day 5 and remained unchanged until day 7. The level of copper in the algae cultivated with copper and 100 or 200 µM of NaHS continuously increased until day 7 and the copper level was higher in the algae cultivated with 200 µM of NaHS compared to 100 µM of NaHS. In contrast, the level of intracellular copper decreased in the algae treated with copper and hypotaurine. The level of intracellular copper did not correlate with the level of GSH or with the expression of UcMTs, and PCs were not detected in response to copper, or copper and NaHS. Algae treated with copper and with copper and 200 µM of NaHS for 5 days were visualized by TEM and the elemental composition of electrondense particles was analyzed by EDXS. The algae treated with copper showed electrondense particles containing copper and sulfur, but not nitrogen, and they were mainly located in the chloroplast, but also in the cytoplasm. The algae treated with copper and NaHS showed a higher level of electrondense particles containing copper and sulfur, but not nitrogen, and they were located in the chloroplast, and in the cytoplasm. Thus, copper is accumulated as copper sulfide insoluble particles, and not bound to GSH, PCs or UcMTs, in the marine alga U. compressa.

Eco-Friendly Transformation of Bioethanol into Ethylene over Bimetallic Nickel-Copper Catalysts.

The conversion of bioethanol to ethylene in gas phase and atmospheric pressure was investigated over γ-Al2O3 supported copper and nickel catalysts. These catalysts were prepared by co-precipitation and pre-treated with hydrogen at 450 °C. Six catalysts were studied at 450 °C under a nitrogen atmosphere. It was found that the monometallic Cu/γ-Al2O3 catalyst exhibited the highest ethylene concentration, with a selectivity of around 90 %. The bioethanol conversion obtained was between 57 %-86 %. Another catalyst that exhibited high concentration values was the NiCu1 : 7 bimetallic catalyst. The catalysts were characterised using XRD, SEM, EDS, TEM, TGA, FTIR, Raman, and N2-physisoption techniques. Furthermore, the Cu/γ-Al2O3 catalyst was studied under different reduction temperatures and gas flow conditions. It was found that the catalysts reduced at 350 °C and 35 ml/min N2 flow presented ethylene concentrations between (0.18-0.21) g/L. Moreover, the catalyst deactivation was identified to be first order and the equation of the Cu/γ-Al2O3 catalyst deactivation model was determined. Carbonaceous deposits over the used sample were not detected by Raman and FTIR. It was determined that the Cu/γ-Al2O3 catalyst deactivation could be mainly attributed to the blocking of the catalytic sites by strongly adsorbed compounds and hydroxylation of the catalyst surface.

Prospective Evaluation of Ease and Difficulties of 869 Cases of Intrauterine Devices Removals.

OBJECTIVES: The objective was to describe the ease and difficulty of removing intrauterine devices (IUDs). METHODS: We conducted a prospective study at the University of Campinas (UNICAMP), Faculty of Medical Sciences, UNICAMP. We included women who requested IUD removal. We excluded women with partial IUD expulsion in which the IUD was protruded at the external os. We identified difficult IUD removal when the removal was challenging, including the inability to visualize IUD strings extending from the cervical os. RESULTS: A total of 869 women participated. Women were aged 29.4 ± 8.0 years (mean ± SD; range 14-51) and the duration of IUD use at the time of removal was 4.3 ± 4.2 years. We found that 702 (80.8%) women had visible strings at the external os and the removals were performed at the first attempt without difficulty in 692 (79.6%) participants. The pain was more intense (>4) in cases of difficult removals. After multivariate logistic analysis, difficult removals were associated with users of IUD ≥3 years (3 times higher risk); for each previous cesarean delivery, the risk increased by 1.5 times. CONCLUSIONS: Our study showed that IUD removal is an easy and safe procedure, with only a small proportion of women reporting significant pain with IUD removal.

Laser Ablation for the Synthesis of Cu/Cu2O/CuO and Its Development as Photocatalytic Material for Escherichia coli Detoxification.

Advanced Oxidation Processes (AOPs) offer promising methods for disinfection by generating radical species like hydroxyl radicals, superoxide anion radicals, and hydroxy peroxyl, which can induce oxidative stress and deactivate bacterial cells. Photocatalysis, a subset of AOPs, activates a semiconductor using specific electromagnetic wavelengths. A novel material, Cu/Cu2O/CuO nanoparticles (NPs), was synthesized via a laser ablation protocol (using a 1064 nm wavelength laser with water as a solvent, with energy ranges of 25, 50, and 80 mJ for 10 min). The target was sintered from 100 °C to 800 °C at rates of 1.6, 1.1, and 1 °C/min. The composite phases of Cu, CuO, and Cu2O showed enhanced photocatalytic activity under visible-light excitation at 368 nm. The size of Cu/Cu2O/CuO NPs facilitates penetration into microorganisms, thereby improving the disinfection effect. This study contributes to synthesizing mixed copper oxides and exploring their activation as photocatalysts for cleaner surfaces. The electronic and electrochemical properties have potential applications in other fields, such as capacitor materials. The laser ablation method allowed for modification of the band gap absorption and enhancement of the catalytic properties in Cu/Cu2O/CuO NPs compared to precursors. The disinfection of E. coli with Cu/Cu2O/CuO systems serves as a case study demonstrating the methodology's versatility for various applications, including disinfection against different microorganisms, both Gram-positive and Gram-negative.

Homo- and Heterogeneous Benzyl Alcohol Catalytic Oxidation Promoted by Mononuclear Copper(II) Complexes: The Influence of the Ligand upon Product Conversion.

The catalytic properties of three copper complexes, [Cu(en)2](ClO4)2 (1), [Cu(amp)2](ClO4)2, (2) and [Cu(bpy)2](ClO4)2 (3) (where en = ethylenediamine, amp = 2-aminomethylpyridine and bpy = 2,2'-bipyridine), were explored upon the oxidation of benzyl alcohol (BnOH). Maximized conversions of the substrates to their respective products were obtained using a multivariate analysis approach, a powerful tool that allowed multiple variables to be optimized simultaneously, thus creating a more economical, fast and effective technique. Considering the studies in a fluid solution (homogeneous), all complexes strongly depended on the amount of the oxidizing agent (H2O2), followed by the catalyst load. In contrast, time seemed to be statistically less relevant for complexes 1 and 3 and not relevant for 2. All complexes showed high selectivity in their optimized conditions, and only benzaldehyde (BA) was obtained as a viable product. Quantitatively, the catalytic activity observed was 3 > 2 > 1, which is related to the π-acceptor character of the ligands employed in the study. Density functional theory (DFT) studies could corroborate this feature by correlating the geometric index for square pyramid Cu(II)-OOH species, which should be generated in the solution during the catalytic process. Complex 3 was successfully immobilized in silica-coated magnetic nanoparticles (Fe3O4@SiO2), and its oxidative activity was evaluated through heterogenous catalysis assays. Substrate conversion promoted by 3-Fe3O4@SiO2 generated only BA as a viable product, and the supported catalyst's recyclability was proven. Reduced catalytic conversions in the presence of the radical scavenger (2,2,6,6-tetrametil-piperidi-1-nil)oxil (TEMPO) indicate that radical and non-radical mechanisms are involved.

Copper recovery by solvent extraction for nanoparticle synthesis from waste motherboards.

Printed circuit boards, which make up part of waste from electrical and electronic equipment, contain elements that can be economically reused, such as copper, silver, gold, and nickel, as well as metals that are harmful to the environment and health, such as lead, mercury, and cadmium. Thus, through recycling this scrap, materials that would otherwise be discarded can be reinserted as secondary raw materials to produce new consumer goods through urban mining. In this context, the synthesis of nanoparticles shows promise as it allows the reinsertion of these materials in the manufacture of new products. Therefore, this study used obsolete computer motherboards as a secondary material to obtain copper to produce nanoparticles of this metal. From a solution based on the leach liquor of this scrap, a purification route using solvent extraction was defined and applied to the real leach liquor. Applying the hydroxyoxime extractant at a dilution of 20% (v/v) in kerosene, A/O of 1/1, 298 K, and 0.25 h of contact during extraction, and stripping in H2SO4 (2 M), 298 K, 0.25 h, W/O ratio of 3/1, and two theoretical countercurrent stages, a solution containing more than 95% of the copper in the leach liquor could be obtained with less than 1% of contaminants. From this purified liquor, nanoparticles containing copper and metallic copper oxides and hydroxides were produced, with an average size of 84 nm, at pH 11, 3 h of hot stirring, volume of 0.015 L of ascorbic acid (0.50 M) and 0.015 L of precursor solution (0.03 M Cu), and temperature (343 K).

L-Citrullinato-Bipyridine and L-Citrullinato-Phenanthroline Mixed Copper Complexes: Synthesis, Characterization and Potential Anticancer Activity.

Citrulline (C6H13N3O3) is an amino acid found in the body as a zwitterion. This means its carboxylic and amine groups can act as Lewis donors to chelate metal cations. In addition, citrulline possesses a terminal ureido group on its aliphatic chain, which also appears to coordinate. Here, two new mixed complexes of citrulline were made with 1,10-phenanthroline and 2,2'-bipyridine. These compounds, once dissolved in water, gave aquo-complexes that were subject to DFT studies and in vitro toxicity studies on cancer cell lines (HeLa, MDA-MB-231, HCT 15, and MCF7) showed promising results. Docking studies with DNA were also conducted, indicating potential anticancer properties.

A Comprehensive Investigation of Methanol Electrooxidation on Copper Anodes: Spectroelectrochemical Insights and Energy Conversion in Microfluidic Fuel Cells.

Here, we comprehensively investigated methanol electrooxidation on Cu-based catalysts, allowing us to build the first microfluidic fuel cell (µFC) equipped with a Cu anode and a metal-free cathode that converts energy from methanol. We applied a simple, fast, small-scale, and surfactant-free strategy for synthesizing Cu-based nanoparticles at room temperature in steady state (ST), under mechanical stirring (MS), or under ultrasonication (US). The morphology evaluation of the Cu-based samples reveals that they have the same nanoparticle (NP) needle-like form. The elemental mapping composition spectra revealed that pure Cu or Cu oxides were obtained for all synthesized materials. In addition to having more Cu2O on the surface, sample US had more Cu(OH)2 than the others, according to X-ray diffractograms and X-ray photoelectron spectroscopy. The sample US is less carbon-contaminated because of the local heating of the sonic bath, which also enhances the cleanliness of the Cu surface. The activity of the Cu NPs was investigated for methanol electrooxidation in an alkaline medium through electrochemical and spectroelectrochemical measurements. The potentiodynamic and potentiostatic experiments showed higher current densities for the NPs synthesized in the US. In situ FTIR experiments revealed that the three synthesized NP materials eletcrooxidize methanol completely to carbonate through formate. Most importantly, all pathways were led without detectable CO, a poisoning molecule not found at high overpotentials. The reaction path using the US electrode experienced an additional round of formate formation and conversion into carbonate (or CO2 in the thin layer) after 1.0 V (vs. Ag/Ag/Cl), suggesting improved catalysis. The high activity of NPs synthesized in the US is attributed to effective dissociative adsorption of the fuel due to the site's availability and the presence of hydroxyl groups that may fasten the oxidation of adsorbates from the surface. After understanding the surface reaction, we built a mixed-media µFC fed by methanol in alkaline medium and sodium persulfate in acidic medium. The µFC was equipped with Cu NPs synthesized in ultrasonic-bath-modified carbon paper as the anode and metal-free carbon paper as the cathode. Since the onset potential for methanol electrooxidation was 0.45 V and the reduction reaction revealed 0.90 V, the theoretical OCV is 0.45 V, which provides a spontaneous coupled redox reaction to produce power. The µFC displayed 0.56 mA cm-2 of maximum current density and 26 µW cm-2 of peak power density at 100 µL min-1. This membraneless system optimizes each half-cell individually, making it possible to build fuel cells with noble metal-free anodes and metal-free cathodes.

On the Use of Styrene-Based Nanoparticles to Mitigate the Effect of Montmorillonite in Copper Sulfide Recovery by Flotation.

Clay minerals have different negative effects on the froth flotation process such as low adsorption of collectors on valuable minerals, increased pulp viscosity, and the reduction in recovery and grade concentrates of copper sulfides. This study aims to evaluate the use of polystyrene-based nanoparticles (NPs) for the froth flotation of chalcopyrite and their ability to mitigate the negative effect of montmorillonite on the recovery of this sulfide. The experimental stage consisted of preparing a type of polystyrene-based nanoparticle (St-CTAB-VI), which was analyzed by dynamic night scattering (DLS) to establish its hydrodynamic size. Then, the effect of NPs on chalcopyrite's angle's in the presence and absence of montmorillonite (15%) was evaluated and compared with the contact angle achieved using potassium amyl xanthate (PAX) and a mixture of PAX and NPs. In addition, zeta potential measurements were carried out to investigate the interactions between the chalcopyrite and the montmorillonite or the NPs under fixed concentrations and microflotation tests were performed employing different times to evaluate the chalcopyrite recovery in the presence of montmorillonite, using NPs and mixtures with PAX. Finally, turbidity analysis as a function of time was performed to evaluate the occurrence of sedimentation and flocculation phenomena in suspensions of 15% montmorillonite in the presence and absence of chalcopyrite, nanoparticles, and mixtures of NPs and PAX. The results indicated that the mixture of NPs and PAX contributed to increasing the contact angle of chalcopyrite in the presence of montmorillonite. This can be associated with the presence of molecular and nanometric collectors that generated a higher hydrophobicity on the chalcopyrite particles, contributing to reducing the presence of clay minerals on the mineral surface. In addition, the mixture of NPs and PAX promoted the generation of nanoparticles on the sulfide mineral surface, which helps to detach the slime and facilitate the bubble/mineral attachment step during flotation.

Hexyltrimethylammonium ion enhances potential copper-chelating properties of ammonium thiomolybdate in an in vivo zebrafish model.

Ammonium and hexyltrimethylammonium thiomolybdates (ATM and ATM-C6) and thiotungstates (ATT and ATT-C6) were synthesized. Their toxicity was evaluated using both in vitro and in vivo approaches via the zebrafish embryo acute toxicity assay (ZFET), while the copper-thiometallate interaction was studied using cyclic voltammetry, as well as in an in vivo assay. Cyclic voltammetry suggests that all thiometallates form complexes with copper in a 2:1 Cu:thiometallate ratio. Both in vitro and in vivo assays demonstrated low toxicity in BALB/3T3 cells and in zebrafish embryos, with high IC50 and LC50 values. Furthermore, the hexyltrimethylammonium ion played a crucial role in enhancing viability and reducing toxicity during prolonged treatments for ATM and ATT. In particular, the ZEFT assay uncovered the accumulation of ATM in zebrafish yolk, averted by the incorporation of the hexyltrimethylammonium ion. Notably, the copper-thiometallate interaction assay highlighted the improved viability of embryos when cultured in CuCl2 and ATM-C6, even at high CuCl2 concentrations. The hatching assay further confirmed that copper-ATM-C6 interaction mitigates inhibitory effects induced by thiomolybdates and CuCl2 when administered individually. These results suggest that the incorporation of the hexyltrimethylammonium ion in ATM increase its ability to interact with copper and its potential application as a copper chelator.

Rhodococcus erythropolis ATCC 4277 behavior against different metals and its potential use in waste biomining.

Rhodococcus erythropolis bacterium is known for its remarkable resistance characteristics that can be useful in several biotechnological processes, such as bioremediation. However, there is scarce knowledge concerning the behavior of this strain against different metals. This study sought to investigate the behavior of R. erythropolis ATCC 4277 against the residue of chalcopyrite and e-waste to verify both resistive capacities to the metals present in these residues and their potential use for biomining processes. These tests were carried out in a stirred tank bioreactor for 48 h, at 24ºC, pH 7.0, using a total volume of 2.0 L containing 2.5% (v/v) of a bacterial pre-culture. The pulp density of chalcopyrite was 5% (w/w), and agitation and oxygen flow rates were set to 250 rpm and 1.5 LO2 min-1, respectively. On the other hand, we utilized a waste of computer printed circuit board (WPCB) with a pulp density of 10% (w/w), agitation at 400 rpm, and an oxygen flow rate of 3.0 LO2 min-1. Metal concentration analyses post-fermentation showed that R. erythropolis ATCC 4277 was able to leach about 38% of the Cu present in the chalcopyrite residue (in ~ 24 h), and 49.5% of Fe, 42.3% of Ni, 27.4% of Al, and 15% Cu present in WPCB (in ~ 24 h). In addition, the strain survived well in the environment containing such metals, demonstrating the potential of using this bacterium for waste biomining processes as well as in other processes with these metals.

Overweight, Obesity, Hypertriglyceridemia, and Insulin Resistance Are Positively Associated with High Serum Copper Levels in Mexican Adults.

Recently, the role of trace elements in the pathophysiology of obesity, insulin resistance (IR), and metabolic diseases has been explored. In this cross-sectional study, we aimed to assess the association of overweight, obesity, and cardiometabolic traits with serum copper (Cu) levels in 346 Mexican adults. Serum Cu level was measured by inductively coupled plasma mass spectrometry (ICP-MS). Anthropometrical data were collected, and biochemical parameters were measured. The triglyceride-glucose (TyG) index was used as a surrogate marker to evaluate IR. Overweight and obesity status was positively associated with the serum Cu level (ß = 19.434 ± 7.309, p = 0.008). Serum Cu level was observed to have a positive association with serum triglycerides level (ß = 0.160 ± 0.045, p < 0.001) and TyG (ß = 0.001 ± 0.001, p < 0.001). Additionally, high serum Cu level was positively associated with overweight and obesity status (odds ratio [OR] = 1.9, 95% confidence interval [95% CI] 1.1-3.4, p = 0.014), hypertriglyceridemia (OR = 3.0, 95% CI 1.7-5.3, p < 0.001), and IR (OR = 2.6, 95% CI 1.4-4.6, p = 0.001). In conclusion, our results suggest that overweight, obesity, hypertriglyceridemia, and IR are positively associated with serum Cu levels in Mexican adults.